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1.30 ! cvs 5: <title>The Languages of Thot</title>
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1.19 cvs 11: <div class="frontmatter" align="center">
1.18 cvs 12: <h1>The Languages of Thot</h1>
13:
14: <h3>Vincent Quint</h3>
15:
16: <h4>Translated from French by Ethan Munson</h4>
17:
1.30 ! cvs 18: <h4>Version of November 21, 2000</h4>
! 19:
! 20: <p>© 1996-2000 INRIA</p>
1.18 cvs 21: <hr>
22: </div>
23:
24: <div class="tableofcontents">
25: <h2><a href="languages.toc.html">Contents</a></h2>
26: <ul>
1.30 ! cvs 27: <li><big><a href="#sect2">The document model of Thot</a></big>
! 28: <ul>
! 29: <li><strong><a href="#sectb21">The logical structure of
! 30: documents</a></strong></li>
! 31: <li><strong><a href="#sectb22">Generic and specific
! 32: structures</a></strong></li>
! 33: <li><strong><a href="#sectb23">Logical structure and physical
! 34: structure</a></strong></li>
! 35: <li><strong><a href="#sectb24">Document structures and object
! 36: structures</a></strong></li>
! 37: </ul>
! 38: </li>
! 39: <li><big><a href="#sect3">The S language</a></big>
! 40: <ul>
! 41: <li><strong><a href="#sectb31">Document meta-structure</a></strong>
! 42: <ul>
! 43: <li><a href="#sectc311">The basic types</a></li>
! 44: <li><a href="#sectc312">Constructed elements</a></li>
! 45: <li><a href="#sectc313">Logical structure constructors</a>
! 46: <ul>
! 47: <li><small><a href="#sectd3131">Aggregate and
! 48: List</a></small></li>
! 49: <li><small><a href="#sectd3132">Choice, Schema, and
! 50: Unit</a></small></li>
! 51: <li><small><a href="#sectd3133">Reference and
! 52: Inclusion</a></small></li>
! 53: <li><small><a href="#sectd3134">Mark pairs</a></small></li>
! 54: <li><small><a href="#sectd3135">Restrictions and
! 55: Extensions</a></small></li>
! 56: <li><small><a href="#sectd3136">Summary</a></small></li>
! 57: </ul>
! 58: </li>
! 59: <li><a href="#sectc314">Associated Elements</a></li>
! 60: <li><a href="#sectc315">Attributes</a></li>
! 61: <li><a href="#sectc316">Discussion of the model</a></li>
! 62: </ul>
! 63: </li>
! 64: <li><strong><a href="#sectb32">The definition language for generic
! 65: structures</a></strong>
! 66: <ul>
! 67: <li><a href="#sectc321">Writing Conventions</a></li>
! 68: <li><a href="#sectc322">Extension schemas</a></li>
! 69: <li><a href="#sectc323">The general organization of structure
! 70: schemas</a></li>
! 71: <li><a href="#sectc324">The default presentation</a></li>
! 72: <li><a href="#sectc325">Global Attributes</a></li>
! 73: <li><a href="#sectc326">Parameters</a></li>
! 74: <li><a href="#sectc327">Structured elements</a></li>
! 75: <li><a href="#sectc328">Structure definitions</a>
! 76: <ul>
! 77: <li><small><a href="#sectd3281">List</a></small></li>
! 78: <li><small><a href="#sectd3282">Aggregate</a></small></li>
! 79: <li><small><a href="#sectd3283">Choice</a></small></li>
! 80: <li><small><a href="#sectd3284">Reference</a></small></li>
! 81: <li><small><a href="#sectd3285">Mark pairs</a></small></li>
! 82: </ul>
! 83: </li>
! 84: <li><a href="#sectc329">Imports</a></li>
! 85: <li><a href="#sectc3210">Extension rules</a></li>
! 86: <li><a href="#sectc3211">Associated elements</a></li>
! 87: <li><a href="#sectc3212">Units</a></li>
! 88: <li><a href="#sectc3213">Skeleton elements</a></li>
! 89: <li><a href="#sectc3214">Exceptions</a></li>
! 90: </ul>
! 91: </li>
! 92: <li><strong><a href="#sectb33">Some examples</a></strong>
! 93: <ul>
! 94: <li><a href="#sectc331">A class of documents: articles</a></li>
! 95: <li><a href="#sectc332">A class of objects: mathematical
! 96: formulas</a></li>
! 97: </ul>
! 98: </li>
! 99: </ul>
! 100: </li>
! 101: <li><big><a href="#sect4">The P language</a></big>
! 102: <ul>
! 103: <li><strong><a href="#sectb41">Document presentation</a></strong>
! 104: <ul>
! 105: <li><a href="#sectc411">Two levels of presentation</a></li>
! 106: <li><a href="#sectc412">Boxes</a></li>
! 107: <li><a href="#sectc413">Views and visibility</a></li>
! 108: <li><a href="#sectc414">Pages</a></li>
! 109: <li><a href="#sectc415">Numbering</a></li>
! 110: <li><a href="#sectc416">Presentation parameters</a></li>
! 111: </ul>
! 112: </li>
! 113: <li><strong><a href="#sectb42">Presentation description
! 114: language</a></strong>
! 115: <ul>
! 116: <li><a href="#sectc421">The organization of a presentation
! 117: schema</a></li>
! 118: <li><a href="#sectc422">Views</a></li>
! 119: <li><a href="#sectc423">Print Views</a></li>
! 120: <li><a href="#sectc424">Counters</a></li>
! 121: <li><a href="#sectc425">Presentation constants</a></li>
! 122: <li><a href="#sectc426">Variables</a></li>
! 123: <li><a href="#sectc427">Default presentation rules</a></li>
! 124: <li><a href="#sectc428">Presentation and page layout boxes</a></li>
! 125: <li><a href="#sectc429">Presentation of structured elements</a></li>
! 126: <li><a href="#sectc4210">Logical attribute presentation</a></li>
! 127: <li><a href="#sectc4212">Value transmission rules</a></li>
! 128: <li><a href="#sectc4213">Presentation rules</a></li>
! 129: <li><a href="#sectc4214">Conditions applying to presentation
! 130: rules</a>
! 131: <ul>
! 132: <li><small><a href="#sectd42141">Conditions based on the logical
! 133: position of the element</a></small></li>
! 134: <li><small><a href="#sectd42142">Conditions on
! 135: references</a></small></li>
! 136: <li><small><a href="#sectd42143">Conditions on logical
! 137: attributes</a></small></li>
! 138: <li><small><a href="#sectd42144">Conditions on page
! 139: breaks</a></small></li>
! 140: <li><small><a href="#sectd42145">Conditions on the element's
! 141: content</a></small></li>
! 142: <li><small><a href="#sectd42146">Conditions on
! 143: counters</a></small></li>
! 144: </ul>
! 145: </li>
! 146: <li><a href="#sectc4215">A presentation rule</a></li>
! 147: <li><a href="#sectc4216">Box axes</a></li>
! 148: <li><a href="#sectc4217">Distance units</a></li>
! 149: <li><a href="#sectc4218">Relative positions</a></li>
! 150: <li><a href="#sectc4219">Box extents</a>
! 151: <ul>
! 152: <li><small><a href="#sectd42191">Fixed extents</a></small></li>
! 153: <li><small><a href="#sectd42192">Relative
! 154: extents</a></small></li>
! 155: <li><small><a href="#sectd42193">Elastic
! 156: extents</a></small></li>
! 157: </ul>
! 158: </li>
! 159: <li><a href="#sectc4220">Overflow</a></li>
! 160: <li><a href="#sectc4221">Inheritance</a></li>
! 161: <li><a href="#sectc4222">Line breaking</a>
! 162: <ul>
! 163: <li><small><a href="#sectd42221">Line spacing</a></small></li>
! 164: <li><small><a href="#sectd42222">First line
! 165: indentation</a></small></li>
! 166: <li><small><a href="#sectd42223">Alignment</a></small></li>
! 167: <li><small><a href="#sectd42224">Justification</a></small></li>
! 168: <li><small><a href="#sectd42225">Hyphenation</a></small></li>
! 169: <li><small><a href="#sectd42226">Avoiding line
! 170: breaking</a></small></li>
! 171: </ul>
! 172: </li>
! 173: <li><a href="#sectc4223">Page breaking and line breaking
! 174: conditions</a></li>
! 175: <li><a href="#sectc4224">Visibility</a></li>
! 176: <li><a href="#sectc4225">Character style parameters</a>
! 177: <ul>
! 178: <li><small><a href="#sectd42251">Character size</a></small></li>
! 179: <li><small><a href="#sectd42252">Font and character
! 180: style</a></small></li>
! 181: <li><small><a href="#sectd42253">Underlining</a></small></li>
! 182: </ul>
! 183: </li>
! 184: <li><a href="#sectc4226">Stacking order</a></li>
! 185: <li><a href="#sectc4227">Line style</a></li>
! 186: <li><a href="#sectc4228">Line thickness</a></li>
! 187: <li><a href="#sectc4229">Fill pattern</a></li>
! 188: <li><a href="#sectc4230">Colors</a></li>
! 189: <li><a href="#sectc4230a">Background color and border</a></li>
! 190: <li><a href="#sectc4230b">Background pictures</a></li>
! 191: <li><a href="#sectc4231">Presentation box content</a></li>
! 192: <li><a href="#sectc4232">Presentation box creation</a></li>
! 193: <li><a href="#sectc4233">Page layout</a></li>
! 194: <li><a href="#sectc4234">Box copies</a></li>
! 195: </ul>
! 196: </li>
! 197: </ul>
! 198: </li>
! 199: <li><big><a href="#sect5">The T language</a></big>
! 200: <ul>
! 201: <li><strong><a href="#sectb51">Document translation</a></strong>
! 202: <ul>
! 203: <li><a href="#sectc511">Translation principles</a></li>
! 204: <li><a href="#sectc512">Translation procedure</a></li>
! 205: </ul>
! 206: </li>
! 207: <li><strong><a href="#sectb52">Translation definition
! 208: language</a></strong>
! 209: <ul>
! 210: <li><a href="#sectc521">Organization of a translation
! 211: schema</a></li>
! 212: <li><a href="#sectc522">Line length</a></li>
! 213: <li><a href="#sectc523">Buffers</a></li>
! 214: <li><a href="#sectc524">Counters</a></li>
! 215: <li><a href="#sectc525">Constants</a></li>
! 216: <li><a href="#sectc526">Variables</a></li>
! 217: <li><a href="#sectc527">Translating structure elements</a></li>
! 218: <li><a href="#sectc528">Conditional rules</a>
! 219: <ul>
! 220: <li><small><a href="#sectd5281">Conditions based on the logical
! 221: position of the element</a></small></li>
! 222: <li><small><a href="#sectd5282">Conditions on
! 223: references</a></small></li>
! 224: <li><small><a href="#sectd5283">Conditions on the
! 225: parameters</a></small></li>
! 226: <li><small><a href="#sectd5284">Conditions on the
! 227: alphabets</a></small></li>
! 228: <li><small><a href="#sectd5285">Conditions on page
! 229: breaks</a></small></li>
! 230: <li><small><a href="#sectd5286">Conditions on the element's
! 231: content</a></small></li>
! 232: <li><small><a href="#sectd5287">Conditions on the presence of
! 233: comments</a></small></li>
! 234: <li><small><a href="#sectd5288">Conditions on the presence of
! 235: specific presentation rules</a></small></li>
! 236: <li><small><a href="#sectd5289">Conditions on the presence of
! 237: logical attributes</a></small></li>
! 238: <li><small><a href="#sectd52810">Conditions on logical
! 239: attributes</a></small></li>
! 240: <li><small><a href="#sectd52811">Conditions on specific
! 241: presentation rules</a></small></li>
! 242: </ul>
! 243: </li>
! 244: <li><a href="#sectc529">Translation rules</a></li>
! 245: <li><a href="#sectc5210">The <tt>Create</tt> rule</a></li>
! 246: <li><a href="#sectc5211">The <tt>Write</tt> rule</a></li>
! 247: <li><a href="#sectc5212">The <tt>Read</tt> rule</a></li>
! 248: <li><a href="#sectc5213">The <tt>Include</tt> rule</a></li>
! 249: <li><a href="#sectc5214">The <tt>Get</tt> rule</a></li>
! 250: <li><a href="#sectc5215">The <tt>Copy</tt> rule</a></li>
! 251: <li><a href="#sectc5216">The <tt>Use</tt> rule</a></li>
! 252: <li><a href="#sectc5217">The <tt>Remove</tt> rule</a></li>
! 253: <li><a href="#sectc5218">The <tt>NoTranslation</tt> rule</a></li>
! 254: <li><a href="#sectc5219">The <tt>NoLineBreak</tt> rule</a></li>
! 255: <li><a href="#sectc5220">The <tt>ChangeMainFile</tt> rule</a></li>
! 256: <li><a href="#sectc5220a">The <tt>RemoveFile</tt> rule</a></li>
! 257: <li><a href="#sectc5221">The <tt>Set</tt> and <tt>Add</tt>
! 258: rules</a></li>
! 259: <li><a href="#sectc5221a">The <tt>Indent</tt> rule</a></li>
! 260: <li><a href="#sectc5222">Rule application order</a></li>
! 261: <li><a href="#sectc5223">Translation of logical attributes</a></li>
! 262: <li><a href="#sectc5224">Translation of specific
! 263: presentations</a></li>
! 264: <li><a href="#sectc5225">Recoding of characters, symbols and
! 265: graphics</a></li>
! 266: </ul>
! 267: </li>
! 268: </ul>
! 269: </li>
! 270: <li><big><a href="#sect6">Language grammars</a></big>
! 271: <ul>
! 272: <li><strong><a href="#sectb61">The M meta-language</a></strong></li>
! 273: <li><strong><a href="#sectb62">The S language</a></strong></li>
! 274: <li><strong><a href="#sectb63">The P language</a></strong></li>
! 275: <li><strong><a href="#sectb64">The T language</a></strong></li>
! 276: </ul>
! 277: </li>
! 278: <li><big><a href="#sect7">Character coding</a></big>
! 279: <ul>
! 280: <li><strong><a href="#sectb71">Characters</a></strong></li>
! 281: <li><strong><a href="#sectb72">Symbols</a></strong></li>
! 282: <li><strong><a href="#sectb73">Graphical elements</a></strong></li>
! 283: </ul>
! 284: </li>
1.18 cvs 285: </ul>
286: <hr>
287: </div>
1.1 cvs 288:
1.18 cvs 289: <div class="chapter">
1.30 ! cvs 290: <h1><a name="sect2">The document model of Thot</a></h1>
1.1 cvs 291:
1.30 ! cvs 292: <p>All of the services which Thot provides to the user are based on the
! 293: system's internal document representation. This representation is itself
! 294: derived from the document model which underlies Thot. The model is presented
! 295: here, prior to the description of the languages which permit the generic
! 296: specification of documents.</p>
1.1 cvs 297:
1.18 cvs 298: <div class="section">
1.30 ! cvs 299: <h2><a name="sectb21">The logical structure of documents</a></h2>
1.1 cvs 300:
1.30 ! cvs 301: <p>The document model of Thot is primarily designed to allow the user to
! 302: operate on those entities which s/he has in mind when s/he works on a
! 303: document. The model makes no assumptions about the nature of these entities.
! 304: It is essentially these logical entities, such as paragraphs, sections,
! 305: chapters, notes, titles, and cross-references which give a document its
! 306: logical structure.</p>
! 307:
! 308: <p>Because of this model, the author can divide the document into chapters,
1.1 cvs 309: giving each one a title. The content of these chapters can be further divided
1.2 cvs 310: into sections, subsections, etc. The text is organized into successive
311: paragraphs, according to the content. In the writing phase, the lines, pages,
312: margins, spacing, fonts, and character styles are not very important. In fact,
313: if the system requires documents to be written in these terms, it gets in the
314: way. So, Thot's model is primarily based on the logical aspect of documents.
1.18 cvs 315: The creation of a model of this type essentially requires the definition :</p>
316: <ul>
1.30 ! cvs 317: <li>of the entities which can appear in the documents,</li>
! 318: <li>and the relations between these entities.</li>
1.18 cvs 319: </ul>
1.30 ! cvs 320:
! 321: <p>The choice of entities to include in the model can be subtle. Some
! 322: documents require chapters, while others only need various levels of sections.
! 323: Certain documents contain appendices, others don't. In different documents
! 324: the same logical entity may go by different names (e.g. ``Conclusion'' and
1.1 cvs 325: ``Summary''). Certain entities which are absolutely necessary in some
326: documents, such as clauses in a contract or the address of the recipient in a
1.18 cvs 327: letter, are useless in most other cases.</p>
1.30 ! cvs 328:
! 329: <p>The differences between documents result from more than just the entities
! 330: that appear in them, but also from the relationships between these entities
! 331: and the ways that they are linked. In certain documents, notes are spread
! 332: throughout the document, for example at the bottom of the page containing the
1.1 cvs 333: cross-reference to them, while in other documents they are collected at the
334: end of each chapter or even at the end of the work. As another example, the
335: introduction of some documents can contain many sections, while in other
336: documents, the introduction is restricted to be a short sequence of
1.18 cvs 337: paragraphs.</p>
1.30 ! cvs 338:
! 339: <p>All of this makes it unlikely that a single model can describe any document
! 340: at a relatively high level. It is obviously tempting to make up a list of
! 341: widely used entities, such as chapters, sections, paragraphs, and titles, and
! 342: then map all other entities onto the available choices. In this way, an
1.1 cvs 343: introduction can be supported as a chapter and a contract clause supported as
344: a paragraph or section. However, in trying to widen the range of usage of
345: certain entities, their meaning can be lost and the power of the model
346: reduced. In addition, while this widening partially solves the problem of
347: choosing entities, it does not solve the problem of their organization: when a
348: chapter must be composed of sections, how does one indicate that an
349: introduction has none when it is merely another chapter? One solution is to
350: include introductions in the list of supported entities. But then, how does
351: one distinguish those introductions which are allowed to have sections from
352: those which are not. Perhaps this could be done by defining two types of
353: introduction. Clearly, this approach risks an infinite expansion of the list
1.18 cvs 354: of widely used entities.</p>
355: </div>
1.1 cvs 356:
1.18 cvs 357: <div class="section">
1.30 ! cvs 358: <h2><a name="sectb22">Generic and specific structures</a></h2>
1.1 cvs 359:
1.30 ! cvs 360: <p>Thus, it is apparently impossible to construct an exhaustive inventory of
! 361: all those entities which are necessary and sufficient to precisely describe
! 362: any document. It also seems impossible to specify all possible arrangements of
1.18 cvs 363: these entities in a document. This is why Thot uses a <em>meta-model</em>
364: instead, which permits the description of numerous <em>models</em>, each one
365: describing a <em>class</em> of documents.</p>
1.30 ! cvs 366:
! 367: <p>A <em>class</em> is a set of documents having very similar structure. Thus,
1.1 cvs 368: the collection of research reports published by a laboratory constitutes a
369: class; the set of commercial proposals by the sales department of a company
370: constitutes another class; the set of articles published by a journal
371: constitutes a third class. Clearly, it is not possible to enumerate every
372: possible document class. It is also clear that new document classes must be
1.18 cvs 373: created to satisfy new needs and applications.</p>
1.30 ! cvs 374:
! 375: <p>To give a more rigorous definition of classes, we must introduce the ideas
! 376: of <em>generic structure</em> and <em>specific structure</em>. Each document
! 377: has a <em>specific structure</em> which organizes the various parts which
! 378: comprise it. We illustrate this with the help of a simple example comparing
! 379: two reports, A and B (<a href="#specstruct">see Figure</a>). The report A
! 380: contains an introduction followed by three chapters and a conclusion. The
! 381: first chapter contains two sections, the second, three sections. That is the
1.18 cvs 382: <em>specific</em> structure of document A. Similarly, the structure of
1.1 cvs 383: document B is: an introduction, two chapters, a conclusion; Chapter 1 has
384: three sections while Chapter 2 has four. The specific structures of these two
1.18 cvs 385: documents are thus different.</p>
1.1 cvs 386:
1.18 cvs 387: <div class="figure">
388: <hr>
389: <pre> Report A Report B
1.1 cvs 390: Introduction Introduction
391: Chapter 1 Chapter 1
392: Section 1.1 Section 1.1
393: Section 1.2 Section 1.2
394: Chapter 2 Section 1.3
395: Section 2.1 Chapter 2
396: Section 2.2 Section 2.1
397: Section 2.3 Section 2.2
398: Chapter 3 Section 2.3
399: Conclusion Section 2.4
1.18 cvs 400: Conclusion</pre>
1.30 ! cvs 401:
! 402: <p align="center"><em><a name="specstruct">Two specific
! 403: structures</a></em></p>
1.18 cvs 404: <hr>
1.30 ! cvs 405: </div>
! 406:
! 407: <p>The <em>generic structure</em> defines the ways in which specific
! 408: structures can be constructed. It specifies how to generate specific
! 409: structures. The reports A and B, though different, are constructed in
! 410: accordance with the same generic structure, which specifies that a report
! 411: contains an introduction followed by a variable number of chapters and a
! 412: conclusion, with each chapter containing a variable number of sections.</p>
! 413:
! 414: <p>There is a one-to-one correspondence between a class and a generic
! 415: structure: all the documents of a class are constructed in accordance with the
! 416: same generic structure. Hence the definition of the class: a class is a set
! 417: of documents whose specific structure is constructed in accordance with the
! 418: same generic structure. A class is characterized by its generic
! 419: structure.</p>
1.19 cvs 420:
1.30 ! cvs 421: <p>Thus, a generic structure can be considered to be a model at the level
! 422: which interests us, but only for one class of documents. When the definition
! 423: is limited to a single class of documents, it is possible to define a model
! 424: which does a good job of representing the documents of the class, including
! 425: the necessary entities and unencumbered by useless entities. The description
! 426: of the organization of the documents in the class can then be sufficiently
1.18 cvs 427: precise.</p>
428: </div>
1.1 cvs 429:
1.18 cvs 430: <div class="section">
1.30 ! cvs 431: <h2><a name="sectb23">Logical structure and physical structure</a></h2>
1.1 cvs 432:
1.30 ! cvs 433: <p>Generic structures only describe the <em>logical</em> organization of
1.18 cvs 434: documents, not their <em>physical</em> presentation on a screen or on sheets
1.1 cvs 435: of paper. However, for a document to be displayed or printed, its graphic
1.18 cvs 436: presentation must be taken into account.</p>
1.30 ! cvs 437:
! 438: <p>An examination of current printed documents shows that the details of
1.1 cvs 439: presentation essentially serve to bring out their logical structure. Outside
440: of some particular domains, notably advertising, the presentation is rarely
441: independent of the logical organization of the text. Moreover, the art of
442: typography consists of enhancing the organization of the text being set,
443: without catching the eye of the reader with overly pronounced effects. Thus,
444: italic and boldface type are used to emphasize words or expressions which have
445: greater significance than the rest of the text: keywords, new ideas,
446: citations, book titles, etc. Other effects highlight the organization of the
447: text: vertical space, margin changes, page breaks, centering, eventually
448: combined with the changes in the shapes or weight of the characters. These
449: effects serve to indicate the transitions between paragraphs, sections, or
450: chapters: an object's level in the logical structure of the document is shown
1.18 cvs 451: by the markedness of the effects.</p>
1.30 ! cvs 452:
! 453: <p>Since the model permits the description of all of the logical structure of
! 454: the document, the presentation can be derived from the model without being
1.1 cvs 455: submerged in the document itself. It suffices to use the logical structure of
456: the document to make the desired changes in its presentation: changes in type
1.18 cvs 457: size, type style, spacing, margin, centering, etc.</p>
1.30 ! cvs 458:
! 459: <p>Just as one cannot define a unique generic logical structure for all
! 460: document classes, one cannot define universal presentation rules which can be
! 461: applied to all document classes. For certain types of documents the chapter
! 462: titles will be centered on the page and printed in large, bold type. For
! 463: other documents, the same chapter titles will be printed in small, italic type
! 464: and aligned on the left margin.</p>
! 465:
! 466: <p>Therefore, it is necessary to base the presentation specifications for
1.1 cvs 467: documents on their class. Such a specification can be very fine-grained,
468: because the presentation is expressed in terms of the entities defined in the
469: generic logical structure of the class. Thus, it is possible to specify a
470: different presentation for the chapter titles and the section titles, and
471: similarly to specify titles for the sections according to their level in the
472: section hierarchy. The set of rules which specify the presentation of all the
1.18 cvs 473: elements defined in a generic logical structure is called a <em>generic
474: presentation</em>.</p>
1.30 ! cvs 475:
! 476: <p>There are several advantages derived from having a presentation linked to
! 477: the generic structure and described by a generic presentation. Homogeneity is
! 478: the first. Since every document in a class corresponds to the same generic
1.1 cvs 479: logical structure, a homogenous presentation for different documents of the
480: same class can be assured by applying the same generic presentation to all
481: documents of the class. Homogeneity of presentation can also be found among
1.2 cvs 482: the entities of a single document: every section heading will be presented in
1.1 cvs 483: the same way, the first line of every paragraph of the same type will have the
1.18 cvs 484: same indentation, etc.</p>
1.30 ! cvs 485:
! 486: <p>Another advantage of this approach to presentation is that it facilitates
1.1 cvs 487: changes to the graphical aspect of documents. A change to the generic
488: presentation rules attached to each type of entity will alter the presentation
489: of the entire document, and will do so homogenously. In this case, the
490: internal homogeneity of the class is no longer assured, but the way to control
491: it is simple. It suffices to adopt a single generic presentation for the
1.18 cvs 492: entire class.</p>
1.30 ! cvs 493:
! 494: <p>If the presentation of the class does not have to be homogenous, then the
1.1 cvs 495: appearance of the document can be adapted to the way it will be used or to the
496: device used to render it. This quality is sufficient to allow the existence
1.18 cvs 497: of <a name="mulpres">many generic presentations</a> for the same document
1.1 cvs 498: class. By applying one or the other of these presentations to it, the document
499: can be seen under different graphical aspects. It must be emphasized that
500: this type of modification of the presentation is not a change to the document
501: itself (in its specific logical structure or its content), but only in its
1.18 cvs 502: appearance at the time of editing or printing.</p>
503: </div>
1.1 cvs 504:
1.18 cvs 505: <div class="section">
1.30 ! cvs 506: <h2><a name="sectb24">Document structures and object structures</a></h2>
1.1 cvs 507:
1.30 ! cvs 508: <p>So far, we have only discussed the global structure of documents and have
! 509: not considered the contents found in that structure. We could limit ourselves
! 510: to purely textual contents by assuming that a title or a paragraph contains a
1.1 cvs 511: simple linear text. But this model would be too restrictive. In fact,
512: certain documents contain not only text, but also contain tables, diagrams,
513: photographs, mathematical formulas, and program fragments. The model must
1.18 cvs 514: permit the representation of such <em>objects</em>.</p>
1.30 ! cvs 515:
! 516: <p>Just as with the whole of the document, the model takes into account the
1.1 cvs 517: logical structure of objects of this type. Some are clearly structured,
518: others are less so. Logical structure can be recognized in mathematical
519: formulas, in tables, and in certain types of diagrams. On the other hand, it
520: is difficult to define the structure of a photograph or of some drawings. But
521: in any case, it does not seem possible to define one unique structure which
522: can represent every one of these types of objects. The approach taken in the
523: definition of meta-structure and document classes also applies to objects.
524: Object classes can be defined which put together objects of similar type,
1.18 cvs 525: constructed from the same generic logical structure.</p>
1.30 ! cvs 526:
! 527: <p>Thus, a mathematical class can be defined and have a generic logical
! 528: structure associated with it. But even if a single generic structure can
! 529: represent a sufficient variety of mathematical formulas, for other objects
! 530: with less rigorous structure, multiple classes must be defined. As for
! 531: documents, using multiple classes assures that the model can describe the full
! 532: range of objects to be presented. It also permits the system to support
! 533: objects which were not initially anticipated. Moreover, this comment applies
! 534: equally to mathematics: different classes of formulas can be described
! 535: depending on the domain of mathematics being described.</p>
! 536:
! 537: <p>Since objects have the same level of logical representation as documents,
! 538: they gain the same advantages. In particular, it is possible to define the
1.1 cvs 539: presentation separately from the objects themselves and attach it to the
540: class. Thus, as for documents, objects of the same type have a uniform
541: presentation and the presentation of every object in a given class can be
542: changed simply by changing the generic presentation of the class. Another
543: advantage of using this document model is that the system does not bother the
544: user with the details of presentation, but rather allows the user to
1.18 cvs 545: concentrate on the logical aspect of the document and the objects.</p>
1.30 ! cvs 546:
! 547: <p>It is clear that the documents in a class do not necessarily use the same
1.1 cvs 548: classes of objects: one technical report will contain tables while another
549: report will have no tables but will use mathematical formulas. The usable
1.2 cvs 550: object classes are not always mentioned in a limiting way in the generic
551: logical structure of documents. Rather, they can be chosen freely from a
1.18 cvs 552: large set, independent of the document class.</p>
1.30 ! cvs 553:
! 554: <p>Thus, the object classes will be made commonplace and usable in every
1.1 cvs 555: document. The notion of ``object'' can be enlarged to include not only
556: non-textual elements, but also certain types of textual elements which can
557: appear in practically every document, whatever their class. Among these
1.2 cvs 558: textual elements, one can mention enumerations, descriptions, examples,
1.18 cvs 559: quotations, even paragraphs.</p>
1.30 ! cvs 560:
! 561: <p>Thus, the document model is not a single, general model describing every
! 562: type of document in one place. Rather, it is a meta-model which can be used
! 563: to describe many different models each of which represents either a class of
1.1 cvs 564: similar documents or a class of similar objects which every document can
1.18 cvs 565: include.</p>
566: </div>
567: <hr>
568: </div>
1.1 cvs 569:
1.18 cvs 570: <div class="chapter">
571: <h1><a name="sect3">The S language</a></h1>
1.1 cvs 572:
1.18 cvs 573: <div class="section">
1.30 ! cvs 574: <h2><a name="sectb31">Document meta-structure</a></h2>
1.1 cvs 575:
1.30 ! cvs 576: <p>Since the concept of meta-structure is well suited to the task of
! 577: describing documents at a high level of abstraction, this meta-structure must
! 578: be precisely defined. Toward that end this section first presents the basic
1.1 cvs 579: elements from which documents and structured objects are composed and then
580: specifies the ways in which these basic elements are assembled into structures
1.18 cvs 581: representing complete documents and objects.</p>
1.1 cvs 582:
1.18 cvs 583: <div class="subsection">
1.30 ! cvs 584: <h3><a name="sectc311">The basic types</a></h3>
1.1 cvs 585:
1.30 ! cvs 586: <p>At the lowest level of a document's structure, the first atom considered is
1.1 cvs 587: the character. However, since characters are seldom isolated, usually
588: appearing as part of a linear sequence, and in order to reduce the complexity
1.18 cvs 589: of the document structure, <em>character strings</em> are used as atoms and
1.1 cvs 590: consecutive characters belonging to the same structural element are grouped in
1.18 cvs 591: the same character string.</p>
1.30 ! cvs 592:
! 593: <p>If the structure of a document is not refined to go down to the level of
1.1 cvs 594: words or phrases, the contents of a simple paragraph can be considered to be a
595: single character string. On the other hand, the title of a chapter, the title
596: of the first section of that chapter, and the text of the first paragraph of
597: that section constitute three different character strings, because they belong
1.18 cvs 598: to distinct structural elements.</p>
1.30 ! cvs 599:
! 600: <p>If, instead, a very fine-grained representation for the structure of a
1.1 cvs 601: document is sought, character strings could be defined to contain only a
602: single word, or even just a single character. This is the case, for example,
603: in programs, for which one wants to retain a structure very close to the
1.2 cvs 604: syntax of the programming language. In this case, an assignment statement
1.1 cvs 605: initializing a simple variable to zero would be composed of two structural
606: elements, the identifier of the variable (a short character string) and the
1.18 cvs 607: assigned value (a string of a single character, `0').</p>
1.30 ! cvs 608:
! 609: <p>The character string is not the only atom necessary for representing those
1.1 cvs 610: documents that interest us. It suffices for purely textual documents, but as
611: soon as the non-textual objects which we have considered arise, there must be
612: other atoms; the number of objects which are to be represented determines the
1.18 cvs 613: number of types of atoms that are necessary.</p>
1.30 ! cvs 614:
! 615: <p>Primitive <em>graphical elements</em> are used for tables and figures of
1.1 cvs 616: different types. These elements are simple geometric shapes like horizontal
617: or vertical lines, which are sufficient for tables, or even oblique lines,
1.2 cvs 618: arrows, rectangles, circles, polygons, and curves for use in figures. From
619: these elements and character strings, graphical objects and tables can be
1.18 cvs 620: constructed.</p>
1.30 ! cvs 621:
! 622: <p>Photographs, though having very little structure, must still appear in
1.18 cvs 623: documents. They are supported by <em>picture</em> elements, which are
624: represented as matrices of pixels.</p>
1.30 ! cvs 625:
! 626: <p>Finally, mathematical notations require certain elements which are
1.18 cvs 627: simultaneously characters and graphical elements, the <em>symbols</em>. By way
1.2 cvs 628: of example, radicals, integration signs, or even large parentheses are
1.1 cvs 629: examples of this type of atom. The size of each of these symbols is
630: determined by its environment, that is to say, by the expression to which it
1.18 cvs 631: is attached.</p>
1.30 ! cvs 632:
! 633: <p>To summarize, the primitive elements which are used in the construction of
1.18 cvs 634: documents and structured objects are:</p>
635: <ul>
1.30 ! cvs 636: <li>character strings,</li>
! 637: <li>graphical elements,</li>
! 638: <li>pictures,</li>
! 639: <li>and mathematical symbols.</li>
1.18 cvs 640: </ul>
641: </div>
1.1 cvs 642:
1.18 cvs 643: <div class="subsection">
1.30 ! cvs 644: <h3><a name="sectc312">Constructed elements</a></h3>
! 645:
! 646: <p>A document is evidently formed from primitive elements. But the model of
! 647: Thot also proposes higher level elements. Thus, in a document composed of
! 648: several chapters, each chapter is an element, and in the chapters each section
! 649: is also an element, and so on. A document is thus an organized set of
! 650: elements.</p>
1.1 cvs 651:
1.30 ! cvs 652: <p>In a document there are different sorts of elements. Each element has a
1.18 cvs 653: <em>type</em> which indicates the role of the element within the document as a
1.1 cvs 654: whole. Thus, we have, for example, the chapter and section types. The
655: document is made up of typed elements: elements of the type chapter and
656: elements of the type section, among others, but also character string elements
657: and graphical elements: the primitive elements are typed elements just as
658: well. At the other extreme, the document itself is also considered to be a
1.18 cvs 659: typed element.</p>
1.30 ! cvs 660:
! 661: <p>The important difference between the primitive elements and the other
! 662: elements of the document is that the primitive elements are atoms (they cannot
! 663: be decomposed), whereas the others, called <em>constructed elements</em>, are
1.1 cvs 664: composed of other elements, which can either be primitive elements or
665: constructed elements. A constructed element of type chapter (or more simply,
666: ``a chapter'') is composed of sections, which are also constructed elements. A
667: paragraph, a constructed element, can be made up of character strings, which
1.18 cvs 668: are primitive elements, and of equations, which are constructed elements.</p>
1.30 ! cvs 669:
! 670: <p>A document is also a constructed element. This is an important point. In
1.1 cvs 671: particular, it allows a document to be treated as part of another document,
672: and conversely, permits a part of a document to be treated as a complete
673: document. Thus, an article presented in a journal is treated by its author as
674: a document in itself, while the editor of the journal considers it to be part
675: of an issue. A table or a figure appearing in a document can be extracted and
676: treated as a complete document, for example to prepare transparencies for a
1.18 cvs 677: conference.</p>
1.30 ! cvs 678:
! 679: <p>These thoughts about types and constructed elements apply just as well to
1.1 cvs 680: objects as they do to documents. A table is a constructed element made up of
681: other constructed elements, rows and columns. A row is formed of cells, which
682: are also constructed elements which contain primitive elements (character
1.18 cvs 683: strings) and/or constructed elements like equations.</p>
684: </div>
1.1 cvs 685:
1.18 cvs 686: <div class="subsection">
1.30 ! cvs 687: <h3><a name="sectc313">Logical structure constructors</a></h3>
1.1 cvs 688:
1.30 ! cvs 689: <p>Having defined the primitive elements and the constructed elements, it is
! 690: now time to define the types of organization which allow the building of
1.18 cvs 691: structures. For this, we rely on the notion of the <em>constructor</em>. A
1.1 cvs 692: constructor defines a way of assembling certain elements in a structure. It
693: resides at the level of the meta-structure: it does not describe the existing
694: relations in a given structure, but rather defines how elements are assembled
1.18 cvs 695: to build a structure that conforms to a model.</p>
1.30 ! cvs 696:
! 697: <p>In defining the overall organization of documents, the first two
! 698: constructors considered are the aggregate and the list.</p>
1.1 cvs 699:
1.18 cvs 700: <div class="subsubsection">
1.30 ! cvs 701: <h4><a name="sectd3131">Aggregate and List</a></h4>
1.1 cvs 702:
1.30 ! cvs 703: <p>The <em>aggregate</em> constructor is used to define constructed element
! 704: types which are collections of a given number of other elements. These
! 705: collections may or may not be ordered. The elements may be either constructed
! 706: or primitive and are specified by their type. A report (that is, a
! 707: constructed element of the report type) has an aggregate structure. It is
! 708: formed from a title, an author's name, an introduction, a body, and a
! 709: conclusion, making it a collection of five element types. This type of
! 710: constructor is found in practically every document, and generally at several
! 711: levels in a document.</p>
! 712:
! 713: <p>The <em>list</em> constructor is used to define constructed elements which
! 714: are ordered sequences of elements (constructed or primitive) having the same
! 715: type. The minimum and maximum numbers of elements for the sequence can be
! 716: specified in the list constructor or the number of elements can be left
! 717: unconstrained. The body of a report is a list of chapters and is typically
! 718: required to contain a minimum of two chapters (is a chapter useful if it is
! 719: the only one in the report?) The chapter itself can contain a list of
! 720: sections, each section containing a list of paragraphs. In the same way as
! 721: the aggregate, the list is a very frequently used constructor in every type of
! 722: document. However, these two constructors are not sufficient to describe every
! 723: document structure; thus other constructors supplement them.</p>
1.18 cvs 724: </div>
1.1 cvs 725:
1.18 cvs 726: <div class="subsubsection">
1.30 ! cvs 727: <h4><a name="sectd3132">Choice, Schema, and Unit</a></h4>
1.1 cvs 728:
1.30 ! cvs 729: <p>The <em>choice</em> constructor is used to define the structure of an
! 730: element type for which one alternative is chosen from several possibilities.
! 731: Thus, a paragraph can be either a simple text paragraph, or an enumeration, or
! 732: a citation.</p>
! 733:
! 734: <p>The choice constructor indicates the complete list of possible options,
! 735: which can be too restrictive in certain cases, the paragraph being one such
! 736: case. Two constructors, <em>unit</em> and <em>schema</em>, address this
1.1 cvs 737: inconvenience. They allow more freedom in the choice of an element type. If
738: a paragraph is defined by a schema constructor, it is possible to put in the
739: place of a paragraph a table, an equation, a drawing or any other object
740: defined by another generic logical structure. It is also possible to define a
741: paragraph as a sequence of units, which could be character strings, symbols,
1.2 cvs 742: or pictures. The choice constructor alone defines a generic logical structure
1.1 cvs 743: that is relatively constrained; in contrast, using units and schemas, a very
1.18 cvs 744: open structure can be defined.</p>
1.30 ! cvs 745:
! 746: <p>The <em>schema</em> constructor represents an object defined by a generic
1.18 cvs 747: logical structure chosen freely from among those available.</p>
1.30 ! cvs 748:
! 749: <p>The <em>unit</em> constructor represents an element whose type can be
! 750: either a primitive type or an element type defined as a unit in the generic
! 751: logical structure of the document, or in another generic logical structure
! 752: used in the document. Such an element may be used in document objects
! 753: constructed according to other generic structures.</p>
! 754:
! 755: <p>Thus, for example, if a cross-reference to a footnote is defined in the
1.1 cvs 756: generic logical structure ``Article'' as a unit, a table (an object defined by
757: another generic structure) can contain cross-references to footnotes, when
758: they appear in an article. In another type of document, a table defined by
759: the same generic structure can contain other types of elements, depending on
760: the type of document into which the table is inserted. All that is needed is
761: to declare, in the generic structure for tables, that the contents of cells
762: are units. In this way, the generic structure of objects is divided up
763: between different types of documents which are able to adapt themselves to the
1.18 cvs 764: environment into which they are inserted.</p>
765: </div>
1.1 cvs 766:
1.18 cvs 767: <div class="subsubsection">
1.30 ! cvs 768: <h4><a name="sectd3133">Reference and Inclusion</a></h4>
1.1 cvs 769:
1.30 ! cvs 770: <p>The <em>reference</em> is used to define document elements that are
1.18 cvs 771: cross-references to other elements, such as a section, a chapter, a
772: bibliographic citation, or a figure. The reference is bi-directional. It can
773: be used to access both the element being cross-referenced and each of the
774: elements which make use of the cross-reference.</p>
1.30 ! cvs 775:
! 776: <p>References can be either <em>internal</em> or <em>external</em>. That is,
1.1 cvs 777: they can designate elements which appear in the same document or in another
1.18 cvs 778: document.</p>
1.30 ! cvs 779:
! 780: <p>The <em><a name="inclusion">inclusion</a></em> constructor is a special
! 781: type of reference. Like the reference, it is an internal or external
! 782: bidirectional link, but it is not a cross-reference. This link represents the
! 783: ``live'' inclusion of the designated element; it accesses the most recent
! 784: version of that element and not a ``dead'' copy, fixed in the state in which
! 785: it was found at the moment the copy was made. As soon as an element is
! 786: modified, all of its inclusions are automatically brought up to date. It must
! 787: be noted that, in addition to inclusion, Thot permits the creation of ``dead''
! 788: copies.</p>
! 789:
! 790: <p>There are three types of inclusions: inclusions with full expansion,
1.1 cvs 791: inclusions with partial expansion, and inclusions without expansion. During
792: editing, inclusions without expansion are represented on the screen by the
793: name of the included document, in a special color, while inclusions with
794: expansion (full or partial) are represented by a copy (full or partial) of the
795: included element (also in a special color). The on-screen representation of a
1.18 cvs 796: partial inclusion is a <a href="#sectc3213">``skeleton''</a> image of the
797: included document.</p>
1.30 ! cvs 798:
! 799: <p>Inclusion with complete expansion can be used to include parts of the same
1.1 cvs 800: document or of other documents. Thus, it can be either an internal or an
801: external link. It can be used to include certain bibliographic entries of a
802: scientific article in another article, or to copy part of a mathematical
803: formula into another formula of the same document, thus assuring that both
1.18 cvs 804: copies will remain synchronized.</p>
1.30 ! cvs 805:
! 806: <p>Inclusion without expansion or with partial expansion is used to include
1.1 cvs 807: complete documents. It is always an external link. It is used primarily to
808: divide very large documents into sub-documents that are easier to manipulate,
809: especially when there are many authors. So, a book can include some chapters,
810: where each chapter is a different document which can be edited separately.
811: When viewing the book on the screen, it might be desirable to see only the
812: titles of the chapters and sections. This can be achieved using inclusion
1.18 cvs 813: with partial expansion.</p>
1.30 ! cvs 814:
! 815: <p>During printing, inclusions without expansion or with partial expansion can
! 816: be represented either as they were shown on the screen or by a complete (and
1.18 cvs 817: up-to-date) copy of the included element or document.</p>
1.30 ! cvs 818:
! 819: <p>The inclusion constructor, whatever its type, respects the generic
! 820: structure: only those elements authorized by the generic structure can be
! 821: included at a given position in a document.</p>
1.18 cvs 822: </div>
1.1 cvs 823:
1.18 cvs 824: <div class="subsubsection">
1.30 ! cvs 825: <h4><a name="sectd3134">Mark pairs</a></h4>
1.1 cvs 826:
1.30 ! cvs 827: <p>It is often useful to delimit certain parts of a document independently
! 828: from the logical structure. For example, one might wish to attach some
! 829: information (in the form of an <a href="#sectc315">attribute</a>) or a
! 830: particular treatment to a group of words or a set of consecutive paragraphs.
! 831: <em>Mark pairs</em> are used to do this.</p>
! 832:
! 833: <p>Mark pairs are elements which are always paired and are terminals in the
1.1 cvs 834: logical structure of the document. Their position in the structure of the
835: document is defined in the generic structure. It is important to note that
1.18 cvs 836: when the terminals of a mark pair are <em>extensions</em> (see the next
837: section), they can be used quite freely.</p>
838: </div>
1.1 cvs 839:
1.18 cvs 840: <div class="subsubsection">
1.30 ! cvs 841: <h4><a name="sectd3135">Restrictions and Extensions</a></h4>
1.1 cvs 842:
1.30 ! cvs 843: <p>The primitive types and the constructors presented so far permit the
1.1 cvs 844: definition of the logical structure of documents and objects in a rigorous
845: way. But this definition can be very cumbersome in certain cases, notably
846: when trying to constrain or extend the authorized element types in a
1.18 cvs 847: particular context. <em>Restrictions</em> and <em>extensions</em> are used to
848: cope with these cases.</p>
1.30 ! cvs 849:
! 850: <p>A restriction associates with a particular element type <em>A</em>, a list
! 851: of those element types which elements of type <em>A</em> may not contain, even
! 852: if the definition of type <em>A</em> and those of its components authorize
! 853: them otherwise. This simplifies the writing of generic logical structures and
1.1 cvs 854: allows limitations to be placed, when necessary, on the choices offered by the
1.18 cvs 855: schema and unit constructors.</p>
1.30 ! cvs 856:
! 857: <p>Extensions are the inverse of restrictions. They identify a list of
! 858: element types whose presence <em>is</em> permitted, even if its definition and
! 859: those of its components do not authorize them otherwise.</p>
1.18 cvs 860: </div>
861:
862: <div class="subsubsection">
1.30 ! cvs 863: <h4><a name="sectd3136">Summary</a></h4>
1.18 cvs 864:
1.30 ! cvs 865: <p>Thus, four constructors are used to construct a document:</p>
1.18 cvs 866: <ul>
1.30 ! cvs 867: <li>the aggregate constructor (ordered or not),</li>
! 868: <li>the list constructor,</li>
! 869: <li>the choice constructor and its extensions, the unit and schema
! 870: constructors,</li>
! 871: <li>the reference constructor and its variant, the inclusion.</li>
! 872: </ul>
! 873:
! 874: <p>These constructors are also sufficient for objects. Thus, these
! 875: constructors provide a homogenous meta-model which can describe both the
! 876: organization of the document as a whole and that of the various types of
! 877: objects which it contains. After presenting the description language for
! 878: generic structures, we will present several examples which illustrate the
! 879: appropriateness of the model.</p>
! 880:
! 881: <p>The first three constructors (aggregate, list and choice) lead to tree-like
1.1 cvs 882: structures for documents and objects, the objects being simply the subtrees of
883: the tree of a document (or even of other objects' subtrees). The reference
884: constructor introduces other, non-hierarchical, relations which augment those
885: of the tree: when a paragraph makes reference to a chapter or a section, that
886: relation leaves the purely tree-like structure. Moreover, external reference
887: and inclusion constructors permit the establishment of links between different
1.18 cvs 888: documents, thus creating a hypertext structure.</p>
889: </div>
890: </div>
1.1 cvs 891:
1.18 cvs 892: <div class="subsection">
1.30 ! cvs 893: <h3><a name="sectc314">Associated Elements</a></h3>
1.1 cvs 894:
1.30 ! cvs 895: <p>Thanks to the list, aggregate and choice constructors, the organization of
! 896: the document is specified rigorously, using constructed and primitive
! 897: elements. But a document is made up of more than just its elements; it clearly
! 898: also contains links between them. There exist elements whose position in the
1.1 cvs 899: document's structure is not determinable. This is notably the case for
900: figures and notes. A figure can be designated at many points in the same
901: document and its place in the physical document can vary over the life of the
902: document without any effect on the meaning or clarity of the document. At one
903: time, it can be placed at the end of the document along with all other
904: figures. At another time, it can appear at the top of the page which follows
905: the first mention of the figure. The figures can be dispersed throughout the
906: document or can be grouped together. The situation is similar for notes,
907: which can be printed at the bottom of the page on which they are mentioned or
908: assembled together at the end of the chapter or even the end of the work. Of
909: course, this brings up questions of the physical position of elements in
910: documents that are broken into pages, but this reflects the structural
911: instability of these elements. They cannot be treated the same way as
912: elements like paragraphs or sections, whose position in the structure is
1.18 cvs 913: directly linked to the semantics of the document.</p>
1.30 ! cvs 914:
! 915: <p>Those elements whose position in the structure of the document is not
! 916: fixed, even though they are definitely part of the document, are called
1.18 cvs 917: <em>associated elements</em>. Associated elements are themselves structures,
1.1 cvs 918: which is to say that their content can be organized logically by the
1.18 cvs 919: constructors from primitive and constructed elements.</p>
1.30 ! cvs 920:
! 921: <p>It can happen that the associated elements are totally disconnected from
! 922: the structure of the document, as in a commentary or appraisal of the entire
! 923: work. But more often, the associated elements are linked to the content of the
1.1 cvs 924: document by references. This is generally the case for notes and figures,
1.18 cvs 925: among others.</p>
1.30 ! cvs 926:
! 927: <p>Thus, associated elements introduce a new use for the reference
! 928: constructor. It not only serves to create links between elements of the
! 929: principal structure of the document, but also serves to link the associated
! 930: elements to the primary structure.</p>
1.18 cvs 931: </div>
1.1 cvs 932:
1.18 cvs 933: <div class="subsection">
1.30 ! cvs 934: <h3><a name="sectc315">Attributes</a></h3>
1.1 cvs 935:
1.30 ! cvs 936: <p>There remain logical aspects of documents that are not entirely described
! 937: by the structure. Certain types of semantic information, which are not stated
1.1 cvs 938: explicitly in the text, must also be taken into account. In particular, such
939: information is shown by typographic effects which do not correspond to a
940: change between structural elements. In fact, certain titles are set in bold
941: or italic or are printed in a different typeface from the rest of the text in
942: order to mark them as structurally distinct. But these same effects
943: frequently appear in the middle of continuous text (e.g. in the interior of a
944: paragraph). In this case, there is no change between structural elements; the
945: effect serves to highlight a word, expression, or phrase. The notion of an
1.18 cvs 946: <em>attribute</em> is used to express this type of information.</p>
1.30 ! cvs 947:
! 948: <p>An attribute is a piece of information attached to a structural element
! 949: which augments the type of the element and clarifies its function in the
! 950: document. Keywords, foreign language words, and titles of other works can all
! 951: be represented by character strings with attached attributes. Attributes may
1.1 cvs 952: also be attached to constructed elements. Thus, an attribute indicating the
953: language can be attached to a single word or to a large part of a
1.18 cvs 954: document.</p>
1.30 ! cvs 955:
! 956: <p>In fact, an attribute can be any piece of information which is linked to a
1.1 cvs 957: part of a document and which can be used by agents which work on the document.
958: For example, the language in which the document is written determines the set
959: of characters used by an editor or formatter. It also determines the
960: algorithm or hyphenation dictionary to be used. The attribute ``keyword''
961: facilitates the work of an information retrieval system. The attribute
962: ``index word'' allows a formatter to automatically construct an index at the
1.18 cvs 963: end of the document.</p>
1.30 ! cvs 964:
! 965: <p>As with the types of constructed elements, the attributes and the values
! 966: they can take are defined separately in each generic logical structure, not in
! 967: the meta-model, according to the needs of the document class or the nature of
! 968: the object.</p>
! 969:
! 970: <p>Many types of attributes are offered: numeric, textual, references, and
1.18 cvs 971: enumerations:</p>
972: <ul>
1.30 ! cvs 973: <li><em>Numeric attributes</em> can take integer values (negative, positive,
! 974: or null).</li>
! 975: <li><em>Textual attributes</em> have as their values character strings.</li>
! 976: <li><em>Reference attributes</em> designate an element of the logical
! 977: structure.</li>
! 978: <li><em>Enumeration attributes</em> can take one value from a limited list
! 979: of possible values, each value being a name.</li>
1.18 cvs 980: </ul>
1.30 ! cvs 981:
! 982: <p>In a generic structure, there is a distinction between <em>global
1.18 cvs 983: attributes</em> and <em>local attributes</em>. A global attribute can be
1.1 cvs 984: applied to every element type defined in the generic structure where it is
985: specified. In contrast, a local attribute can only be applied to certain
986: types of elements, even only a single type. The ``language'' attribute
987: presented above is an example of a global attribute. An example of a local
988: attribute is the rank of an author (principal author of the document or
989: secondary author): this attribute can only be applied sensibly to an element
1.18 cvs 990: of the ``author'' type.</p>
1.30 ! cvs 991:
! 992: <p>Attributes can be assigned to the elements which make up the document in
! 993: many different ways. The author can freely and dynamically place them on any
! 994: part of the document in order to attach supplementary information of his/her
1.18 cvs 995: choice. However, attributes may only be assigned in accordance with the rules
996: of the generic structure; in particular, local attributes can only be assigned
997: to those element types for which they are defined.</p>
1.30 ! cvs 998:
! 999: <p>In the generic structure, certain local attributes can be made mandatory
! 1000: for certain element types. In this case, Thot automatically associates the
1.2 cvs 1001: attribute with the elements of this type and it requires the user to provide a
1.18 cvs 1002: value for this attribute.</p>
1.30 ! cvs 1003:
! 1004: <p>Attributes can also be automatically assigned, with a given value, by every
1.1 cvs 1005: application processing the document in order to systematically add a piece of
1006: information to certain predefined elements of the document. By way of
1007: example, in a report containing a French abstract and an English abstract,
1008: each of the two abstracts is defined as a sequence of paragraphs. The first
1009: abstract has a value of ``French'' for the ``language'' attribute while the
1.18 cvs 1010: second abstract's ``language'' attribute has a value of ``English''.</p>
1.30 ! cvs 1011:
! 1012: <p>In the case of mark pairs, attributes are logically associated with the
! 1013: pair as a whole, but are actually attached to the first mark.</p>
1.18 cvs 1014: </div>
1.1 cvs 1015:
1.18 cvs 1016: <div class="subsection">
1.30 ! cvs 1017: <h3><a name="sectc316">Discussion of the model</a></h3>
1.1 cvs 1018:
1.30 ! cvs 1019: <p>The notions of attribute, constructor, structured element, and associated
1.1 cvs 1020: element are used in the definition of generic logical structures of documents
1021: and objects. The problem is to assemble them to form generic structures. In
1022: fact, many types of elements and attributes can be found in a variety of
1023: generic structures. Rather than redefine them for each structure in which
1024: they appear, it is best to share them between structures. The object classes
1025: already fill this sharing function. If a mathematical class is defined, its
1026: formulas can be used in many different document classes, without redefining
1027: the structure of each class. This problem arises not only for the objects
1028: considered here; it also arises for the commonplace textual elements found in
1029: many document classes. This is the reason why the notion of object is so
1030: broad and why paragraphs and enumerations are also considered to be objects.
1031: These object classes not only permit the sharing of the structures of
1.18 cvs 1032: elements, but also of the attributes defined in the generic structures.</p>
1.30 ! cvs 1033:
! 1034: <p>Structure, such as that presented here, can appear very rigid, and it is
1.1 cvs 1035: possible to imagine that a document editing system based on this model could
1036: prove very constraining to the user. This is, in fact, a common criticism of
1037: syntax-directed editors. This defect can be avoided with Thot, primarily for
1.18 cvs 1038: three reasons:</p>
1039: <ul>
1.30 ! cvs 1040: <li>the generic structures are not fixed in the model itself,</li>
! 1041: <li>the model takes the dynamics of documents into account,</li>
! 1042: <li>the constructors offer great flexibility.</li>
1.18 cvs 1043: </ul>
1.30 ! cvs 1044:
! 1045: <p>When the generic structure of a document is not predefined, but rather is
1.1 cvs 1046: constructed specifically for each document class, it can be carefully adapted
1047: to the current needs. In cases where the generic structure is inadequate for
1048: a particular document of the class, it is always possible either to create a
1049: new class with a generic structure well suited to the new case or to extend
1050: the generic structure of the existing class to take into account the specifics
1051: of the document which poses the problem. These two solutions can also be
1.18 cvs 1052: applied to objects whose structures prove to be poorly designed.</p>
1.30 ! cvs 1053:
! 1054: <p>The model is sufficiently flexible to take into account all the phases of
! 1055: the life of the document. When a generic structure specifies that a report
! 1056: must contain a title, an abstract, an introduction, at least two chapters, and
! 1057: a conclusion, this means only that a report, <em>upon completion</em>, will
! 1058: have to contain all of these elements. When the author begins writing, none
! 1059: of these elements is present. Thot uses this model. Therefore, it tolerates
1.2 cvs 1060: documents which do not conform strictly to the generic structure of their
1061: class; it also considers the generic logical structure to be a way of helping
1.18 cvs 1062: the user in the construction of a complex document.</p>
1.30 ! cvs 1063:
! 1064: <p>In contrast, other applications may reject a document which does not
! 1065: conform strictly to its generic structure. This is, for example, what is done
! 1066: by compilers which refuse to generate code for a program which is not
1.1 cvs 1067: syntactically correct. This might also occur when using a document
1.18 cvs 1068: application for a report which does not have an abstract or title.</p>
1.30 ! cvs 1069:
! 1070: <p>The constructors of the document model bring a great flexibility to the
1.1 cvs 1071: generic structures. A choice constructor (and even more, a unit or schema
1072: constructor) can represent several, very different elements. The list
1073: constructor permits the addition of more elements of the same type. Used
1074: together, these two constructors permit any series of elements of different
1075: types. Of course, this flexibility can be reduced wherever necessary since a
1076: generic structure can limit the choices or the number of elements in a
1.18 cvs 1077: list.</p>
1.30 ! cvs 1078:
! 1079: <p>Another difficulty linked to the use of structure in the document model
1.1 cvs 1080: resides in the choice of the level of the structure. The structure of a
1081: discussion could be extracted from the text itself via linguistic analysis.
1082: Some studies are exploring this approach, but the model of Thot excludes this
1083: type of structure. It only takes into account the logical structure provided
1.18 cvs 1084: explicitly by the author.</p>
1.30 ! cvs 1085:
! 1086: <p>However, the level of structure of the model is not imposed. Each generic
1.1 cvs 1087: structure defines its own level of structure, adapted to the document class or
1088: object and to the ways in which it will be processed. If it will only be
1089: edited and printed, a relatively simple structure suffices. If more
1090: specialized processing will be applied to it, the structure must represent the
1091: element types on which this processing must act. By way of example, a simple
1092: structure is sufficient for printing formulas, but a more complex structure is
1093: required to perform symbolic or numeric calculations on the mathematical
1.18 cvs 1094: expressions. The document model of Thot allows both types of structure.</p>
1095: </div>
1096: </div>
1.1 cvs 1097:
1.18 cvs 1098: <div class="section">
1.30 ! cvs 1099: <h2><a name="sectb32">The definition language for generic structures</a></h2>
1.1 cvs 1100:
1.30 ! cvs 1101: <p>Generic structures, which form the basis of the document model of Thot, are
1.1 cvs 1102: specified using a special language. This definition language, called S, is
1.18 cvs 1103: described in this section.</p>
1.30 ! cvs 1104:
! 1105: <p>Each generic structure, which defines a class of documents or objects, is
1.2 cvs 1106: specified by a file, written in the S language, which is called a
1.18 cvs 1107: <em>structure schema</em>. Structure schemas are compiled into tables, called
1108: structure tables, which are used by Thot and which determine its behavior.</p>
1.1 cvs 1109:
1.18 cvs 1110: <div class="subsection">
1.30 ! cvs 1111: <h3><a name="sectc321">Writing Conventions</a></h3>
1.1 cvs 1112:
1.30 ! cvs 1113: <p>The grammar of S, like those of the languages P and T presented later, is
1.1 cvs 1114: described using the meta-language M, derived from the Backus-Naur Form
1.18 cvs 1115: (BNF).</p>
1.30 ! cvs 1116:
! 1117: <p>In this meta-language each rule of the grammar is composed of a grammar
! 1118: symbol followed by an equals sign (`=') and the right part of the rule. The
! 1119: equals sign plays the same role as the traditional `::=' of BNF: it indicates
! 1120: that the right part defines the symbol of the left part. In the right
! 1121: part,</p>
1.18 cvs 1122: <dl>
1.30 ! cvs 1123: <dt>concatenation</dt>
! 1124: <dd>is shown by the juxtaposition of symbols;</dd>
! 1125: <dt>character strings</dt>
! 1126: <dd>between apostrophes ' represent terminal symbols, that is, keywords in
! 1127: the language defined. Keywords are written here in upper-case letters,
! 1128: but can be written in any combination of upper and lower-case letters.
! 1129: For example, the keyword <tt>DEFPRES</tt> of S can also be written as
! 1130: <tt>defpres</tt> or <tt>DefPres</tt>.</dd>
! 1131: <dt>material between brackets</dt>
! 1132: <dd>(`[' and `]') is optional;</dd>
! 1133: <dt>material between angle brackets</dt>
! 1134: <dd>(`<' and `>') can be repeated many times or omitted;</dd>
! 1135: <dt>the slash</dt>
! 1136: <dd>(`/') indicates an alternative, a choice between the options separated
! 1137: by the slash character;</dd>
! 1138: <dt>the period</dt>
! 1139: <dd>marks the end of a rule;</dd>
! 1140: <dt>text between braces</dt>
! 1141: <dd>(`{' and `}') is simply a comment.</dd>
1.18 cvs 1142: </dl>
1.30 ! cvs 1143:
! 1144: <p>The M meta-language also uses the concepts of identifiers, strings, and
1.18 cvs 1145: integers:</p>
1146: <dl>
1.30 ! cvs 1147: <dt><tt>NAME</tt></dt>
! 1148: <dd>represents an identifier, a sequence of letters (upper or lower-case),
! 1149: digits, and underline characters (`_'), beginning with a letter. Also
! 1150: considered a letter is the sequence of characters `<tt>\nnn</tt>' where
! 1151: the letter <tt>n</tt> represents the ISO Latin-1 code of the letter in
! 1152: octal. It is thus possible to use accented letters in identifiers. The
! 1153: maximum length of identifiers is fixed by the compiler. It is normally
! 1154: 31 characters.
! 1155: <p>Unlike keywords, upper and lower-case letters are distinct in
! 1156: identifiers. Thus, <tt>Title</tt>, <tt>TITLE</tt>, and <tt>title</tt>
! 1157: are considered different identifiers.</p>
! 1158: </dd>
! 1159: <dt><tt>STRING</tt></dt>
! 1160: <dd>represents a string. This is a string of characters delimited by
! 1161: apostrophes. If an apostrophe must appear in a string, it is doubled.
! 1162: As with identifiers, strings can contain characters represented by their
! 1163: octal code (after a backslash). As with apostrophes, if a backslash
! 1164: must appear in a string, it is doubled.</dd>
! 1165: <dt><tt>NUMBER</tt></dt>
! 1166: <dd>represents a positive integer or zero (without a sign), or said
! 1167: another way, a sequence of decimal digits.</dd>
1.18 cvs 1168: </dl>
1.30 ! cvs 1169:
! 1170: <p>The M language can be used to define itself as follows:</p>
1.18 cvs 1171: <pre>{ Any text between braces is a comment. }
1.30 ! cvs 1172: Grammar = Rule < Rule > 'END' .
! 1173: { The < and > signs indicate zero }
1.1 cvs 1174: { or more repetitions. }
1175: { END marks the end of the grammar. }
1176: Rule = Ident '=' RightPart '.' .
1177: { The period indicates the end of a rule }
1178: RightPart = RtTerminal / RtIntermed .
1179: { The slash indicates a choice }
1180: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
1181: { Right part of a terminal rule }
1.30 ! cvs 1182: RtIntermed = Possibility < '/' Possibility > .
1.1 cvs 1183: { Right part of an intermediate rule }
1.30 ! cvs 1184: Possibility = ElemOpt < ElemOpt > .
! 1185: ElemOpt = Element / '[' Element < Element > ']' /
! 1186: '<' Element < Element > '>' .
1.1 cvs 1187: { Brackets delimit optional parts }
1188: Element = Ident / KeyWord .
1189: Ident = NAME .
1190: { Identifier, sequence of characters }
1191: KeyWord = STRING .
1192: { Character string delimited by apostrophes }
1.18 cvs 1193: END</pre>
1194: </div>
1.1 cvs 1195:
1.18 cvs 1196: <div class="subsection">
1.30 ! cvs 1197: <h3><a name="sectc322">Extension schemas</a></h3>
1.1 cvs 1198:
1.30 ! cvs 1199: <p>A structure schema defines the generic logical structure of a class of
1.1 cvs 1200: documents or objects, independent of the operations which can be performed on
1201: the documents. However, certain applications may require particular
1202: information to be represented by the structure for the documents that they
1203: operate on. Thus a document version manager will need to indicate in the
1204: document the parts which belong to one version or another. An indexing system
1205: will add highly-structured index tables as well as the links between these
1.18 cvs 1206: tables and the rest of the document.</p>
1.30 ! cvs 1207:
! 1208: <p>Thus, many applications need to extend the generic structure of the
! 1209: documents on which they operate to introduce new attributes, associated
! 1210: elements or element types. These additions are specific to each application
! 1211: and must be able to be applied to any generic structure: users will want to
! 1212: manage versions or construct indices for many types of documents. Extension
! 1213: schemas fulfill this role: they define attributes, elements, associated
! 1214: elements, units, etc., but they can only be used jointly with a structure
! 1215: schema that they complete. Otherwise, structure schemas can always be used
! 1216: without these extensions when the corresponding applications are not
! 1217: available.</p>
1.18 cvs 1218: </div>
1.1 cvs 1219:
1.18 cvs 1220: <div class="subsection">
1.30 ! cvs 1221: <h3><a name="sectc323">The general organization of structure schemas</a></h3>
1.1 cvs 1222:
1.30 ! cvs 1223: <p>Every structure schema begins with the keyword <tt>STRUCTURE</tt> and ends
1.18 cvs 1224: with the keyword <tt>END</tt>. The keyword <tt>STRUCTURE</tt> is followed by
1225: the keyword <tt>EXTENSION</tt> in the case where the schema defines an
1.1 cvs 1226: extension, then by the name of the generic structure which the schema defines
1227: (the name of the document or object class). The name of the structure is
1.18 cvs 1228: followed by a semicolon.</p>
1.30 ! cvs 1229:
! 1230: <p>In the case of a complete schema (that is, a schema which is not an
1.1 cvs 1231: extension), the definition of the name of the structure is followed by the
1232: declarations of the default presentation schema, the global attributes, the
1233: parameters, the structure rules, the associated elements, the units, the
1234: skeleton elements and the exceptions. Only the definition of the structure
1235: rules is required. Each series of declarations begins with a keyword:
1.18 cvs 1236: <tt>DEFPRES</tt>, <tt>ATTR</tt>, <tt>PARAM</tt>, <tt>STRUCT</tt>,
1237: <tt>ASSOC</tt>, <tt>UNITS</tt>, <tt>EXPORT</tt>, <tt>EXCEPT</tt>.</p>
1.30 ! cvs 1238:
! 1239: <p>In the case of an extension schema, there are neither parameters nor
! 1240: skeleton elements and the <tt>STRUCT</tt> section is optional, while that
! 1241: section is required in a schema that is not an extension. On the other hand,
! 1242: extension schemas can contain an <tt>EXTENS</tt> section, which must not
! 1243: appear in a schema which is not an extension; this section defines the
! 1244: complements to attach to the rules found in the schema to which the extension
! 1245: will be added. The sections <tt>ATTR</tt>, <tt>STRUCT</tt>, <tt>ASSOC</tt>,
! 1246: and <tt>UNITS</tt> define new attributes, new elements, new associated
! 1247: elements, and new units which add their definitions to the principal
! 1248: schema.</p>
1.18 cvs 1249: <pre> StructSchema ='STRUCTURE' ElemID ';'
1.1 cvs 1250: 'DEFPRES' PresID ';'
1251: [ 'ATTR' AttrSeq ]
1252: [ 'PARAM' RulesSeq ]
1253: 'STRUCT' RulesSeq
1254: [ 'ASSOC' RulesSeq ]
1255: [ 'UNITS' RulesSeq ]
1256: [ 'EXPORT' SkeletonSeq ]
1257: [ 'EXCEPT' ExceptSeq ]
1258: 'END' .
1.18 cvs 1259: ElemID = NAME .</pre>
1.30 ! cvs 1260:
! 1261: <p>or</p>
1.18 cvs 1262: <pre> ExtensSchema ='STRUCTURE' 'EXTENSION' ElemID ';'
1.1 cvs 1263: 'DEFPRES' PresID ';'
1264: [ 'ATTR' AttrSeq ]
1265: [ 'STRUCT' RulesSeq ]
1266: [ 'EXTENS' ExtensRuleSeq ]
1267: [ 'ASSOC' RulesSeq ]
1268: [ 'UNITS' RulesSeq ]
1269: [ 'EXCEPT' ExceptSeq ]
1270: 'END' .
1.18 cvs 1271: ElemID = NAME .</pre>
1272: </div>
1.1 cvs 1273:
1.18 cvs 1274: <div class="subsection">
1.30 ! cvs 1275: <h3><a name="sectc324">The default presentation</a></h3>
1.1 cvs 1276:
1.30 ! cvs 1277: <p>It was shown <a href="#mulpres">above</a> that many different presentations
1.1 cvs 1278: are possible for documents and objects of the same class. The structure
1.18 cvs 1279: schema defines a preferred presentation for the class, called the <em>default
1280: presentation</em>. Like generic structures, presentations are described by
1281: programs, called <em>presentation schemas</em>, which are written in a
1282: specific language, P, presented <a href="#sectb42">later</a> in this document.
1283: The name appearing after the keyword <tt>DEFPRES</tt> is the name of the
1.2 cvs 1284: default presentation schema. When a new document is created, Thot will use
1285: this presentation schema by default, but the user remains free to choose
1.18 cvs 1286: another if s/he wishes.</p>
1287: <pre> PresID = NAME .</pre>
1288: </div>
1.1 cvs 1289:
1.18 cvs 1290: <div class="subsection">
1.30 ! cvs 1291: <h3><a name="sectc325">Global Attributes</a></h3>
1.1 cvs 1292:
1.30 ! cvs 1293: <p>If the generic structure includes global attributes of its own, they are
1.18 cvs 1294: declared after the keyword <tt>ATTR</tt>. Each global attribute is defined by
1.1 cvs 1295: its name, followed by an equals sign and the definition of its type. The
1.18 cvs 1296: declaration of a global attribute is terminated by a semi-colon.</p>
1.30 ! cvs 1297:
! 1298: <p>For attributes of the numeric, textual, or reference types, the type is
1.18 cvs 1299: indicated by a keyword, <tt>INTEGER</tt>, <tt>TEXT</tt>, or <tt>REFERENCE</tt>
1300: respectively.</p>
1.30 ! cvs 1301:
! 1302: <p>In the case of a reference attribute, the keyword <tt>REFERENCE</tt> is
1.1 cvs 1303: followed by the type of the referenced element in parentheses. It can refer
1.18 cvs 1304: to any type at all, specified by using the keyword <tt>ANY</tt>, or to a
1.1 cvs 1305: specific type. In the latter case, the element type designated by the
1.18 cvs 1306: reference can be defined either in the <a href="#sectc327"><tt>STRUCT</tt>
1307: section</a> of the same structure schema or in the <tt>STRUCT</tt> section of
1.1 cvs 1308: another structure schema. When the type is defined in another schema, the
1309: element type is followed by the name of the structure schema (within
1310: parentheses) in which it is defined. The name of the designated element type
1.18 cvs 1311: can be preceded by the keyword <tt>First</tt> or <tt>Second</tt>, but only in
1312: the case where the type is defined as <a href="#sectd3285">a pair</a>. These
1.1 cvs 1313: keywords indicate whether the attribute must designate the first mark of the
1314: pair or the second. If the reference refers to a pair and neither of these
1.18 cvs 1315: two keywords is present, then the first mark is used.</p>
1.30 ! cvs 1316:
! 1317: <p>In the case of an enumeration attribute, the equals sign is followed by the
1.1 cvs 1318: list of names representing the possible values of the attribute, the names
1319: being separated from each other by commas. An enumeration attribute has at
1320: least one possible value; the maximum number of values is defined by the
1.18 cvs 1321: compiler for the S language.</p>
1.30 ! cvs 1322: <pre> AttrSeq = Attribute < Attribute > .
1.1 cvs 1323: Attribute = AttrID '=' AttrType ';' .
1324: AttrType = 'INTEGER' / 'TEXT' /
1325: 'REFERENCE' '(' RefType ')' /
1326: ValueSeq .
1327: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .
1328: FirstSec = 'First' / 'Second' .
1329: ExtStruct = '(' ElemID ')' .
1.30 ! cvs 1330: ValueSeq = AttrVal < ',' AttrVal > .
1.1 cvs 1331: AttrID = NAME .
1.18 cvs 1332: AttrVal = NAME .</pre>
1.30 ! cvs 1333:
! 1334: <p>There is a predefined global text attribute, the <em>language</em>, which
! 1335: is automatically added to every Thot structure schema. This attribute allows
1.2 cvs 1336: Thot to perform certain actions, such as hyphenation and spell-checking, which
1337: cannot be performed without knowing the language in which each part of the
1338: document is written. This attribute can be used just like any explicitly
1.18 cvs 1339: declared attribute: the system acts as if every structure schema contains</p>
1340: <pre>ATTR
1341: Language = TEXT;</pre>
1.30 ! cvs 1342:
1.18 cvs 1343: <blockquote class="example">
1.30 ! cvs 1344: <p><strong>Example:</strong></p>
! 1345:
! 1346: <p>The following specification defines the global enumeration attribute
! 1347: WordType.</p>
! 1348: <pre>ATTR
1.18 cvs 1349: WordType = Definition, IndexWord, DocumentTitle;</pre>
1350: </blockquote>
1351: </div>
1.1 cvs 1352:
1.18 cvs 1353: <div class="subsection">
1.30 ! cvs 1354: <h3><a name="sectc326">Parameters</a></h3>
1.1 cvs 1355:
1.30 ! cvs 1356: <p>A parameter is a document element which can appear many times in the
! 1357: document, but always has the same value. This value can only be modified in a
1.1 cvs 1358: controlled way by certain applications. For example, in an advertising
1359: circular, the name of the recipient may appear in the address part and in the
1360: text of the circular. If the recipient's name were a parameter, it might only
1.18 cvs 1361: be able to be changed by a ``mail-merge'' application.</p>
1.30 ! cvs 1362:
! 1363: <p>Parameters are not needed for every document class, but if the schema
! 1364: includes parameters they are declared after the keyword <tt>PARAM</tt>. Each
! 1365: parameter declaration is made in the same way as a <a
! 1366: href="#sectc327">structure element declaration</a>.</p>
! 1367:
! 1368: <p>During editing, Thot permits the insertion of parameters wherever the
1.1 cvs 1369: structure schema allows; it also permits the removal of parameters which are
1370: already in the document but does not allow the modification of the parameter's
1.2 cvs 1371: content in any way. The content is generated automatically by Thot during the
1372: creation of the parameter, based on the value of the parameter in the
1.18 cvs 1373: document.</p>
1374: </div>
1.1 cvs 1375:
1.18 cvs 1376: <div class="subsection">
1.30 ! cvs 1377: <h3><a name="sectc327">Structured elements</a></h3>
1.1 cvs 1378:
1.30 ! cvs 1379: <p>The rules for defining structured elements are required, except in an
1.1 cvs 1380: extension schema: they constitute the core of a structure schema, since they
1381: define the structure of the different types of elements that occur in a
1.18 cvs 1382: document or object of the class defined by the schema.</p>
1.30 ! cvs 1383:
! 1384: <p>The first structure rule after the keyword <tt>STRUCT</tt> must define the
1.1 cvs 1385: structure of the class whose name appears in the first instruction
1.18 cvs 1386: (<tt>STRUCTURE</tt>) of the schema. This is the root rule of the schema,
1387: defining the root of the document tree or object tree.</p>
1.30 ! cvs 1388:
! 1389: <p>The remaining rules may be placed in any order, since the language permits
! 1390: the definition of element types before or after their use, or even in the same
1.1 cvs 1391: instruction in which they are used. This last case allows the definition of
1.18 cvs 1392: recursive structures.</p>
1.30 ! cvs 1393:
! 1394: <p>Each rule is composed of a name (the name of the element type whose
! 1395: structure is being defined) followed by an equals sign and a structure
! 1396: definition.</p>
! 1397:
! 1398: <p>If any local attributes are associated with the element type defined by the
1.2 cvs 1399: rule, they appear between parentheses after the type name and before the
1.18 cvs 1400: equals sign. The parentheses contain, first, the keyword <tt>ATTR</tt>, then
1.2 cvs 1401: the list of local attributes, separated by commas. Each local attribute is
1402: composed of the name of the attribute followed by an equals sign and the
1.18 cvs 1403: definition of the attribute's type, just as in the definition of <a
1404: href="#sectc325">global attributes</a>. The name of the attribute can be
1.2 cvs 1405: preceded by an exclamation point to indicate that the attribute must always be
1406: present for this element type. The same attribute, identified by its name,
1407: can be defined as a local attribute for multiple element types. In this
1408: case, the equals sign and definition of the attribute type need only appear in
1409: the first occurrence of the attribute. It should be noted that global
1.18 cvs 1410: attributes cannot also be defined as local attributes.</p>
1.30 ! cvs 1411:
! 1412: <p>If any <a href="#sectd3135">extensions</a> are defined for this element
! 1413: type, a plus sign follows the structure definition and the names of the
! 1414: extension element types appear between parentheses after the plus. If there
! 1415: are multiple extensions, they are separated by commas. These types can either
! 1416: be defined in the same schema, defined in other schemas, or they may be base
1.18 cvs 1417: types identified by the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>,
1418: <tt>SYMBOL</tt>, or <tt>PICTURE</tt>.</p>
1.30 ! cvs 1419:
! 1420: <p><a href="#sectd3135">Restrictions</a> are indicated in the same manner as
1.18 cvs 1421: extensions, but they are introduced by a minus sign and they come after the
1422: extensions, or if there are no extensions, after the structure definition.</p>
1.30 ! cvs 1423:
! 1424: <p>If the values of attributes must be attached systematically to this element
1.18 cvs 1425: type, they are introduced by the keyword <tt>WITH</tt> and declared in the
1.1 cvs 1426: form of a list of fixed-value attributes. When such definitions of fixed
1.18 cvs 1427: attribute values appear, they are always the last part of the rule.</p>
1.30 ! cvs 1428:
! 1429: <p>The rule is terminated by a semicolon.</p>
! 1430: <pre> RuleSeq = Rule < Rule > .
1.1 cvs 1431: Rule = ElemID [ LocAttrSeq ] '=' DefWithAttr ';'.
1.30 ! cvs 1432: LocAttrSeq = '(' 'ATTR' LocAttr < ';' LocAttr > ')' .
1.1 cvs 1433: LocAttr = [ '!' ] AttrID [ '=' AttrType ] .
1434: DefWithAttr = Definition
1435: [ '+' '(' ExtensionSeq ')' ]
1436: [ '-' '(' RestrictSeq ')' ]
1437: [ 'WITH' FixedAttrSeq ] .
1.30 ! cvs 1438: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1.1 cvs 1439: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
1440: 'SYMBOL' / 'PICTURE' .
1.30 ! cvs 1441: RestrictSeq = RestrictElem < ',' RestrictElem > .
1.1 cvs 1442: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
1.18 cvs 1443: 'SYMBOL' / 'PICTURE' .</pre>
1.30 ! cvs 1444:
! 1445: <p>The list of fixed-value attributes is composed of a sequence of
1.1 cvs 1446: attribute-value pairs separated by commas. Each pair contains the name of the
1447: attribute and the fixed value for this element type, the two being separated
1448: by an equals sign. If the sign is preceded by a question mark the given value
1449: is only an initial value that may be modified later rather than a value fixed
1450: for all time. Reference attributes are an exception to this norm. They
1451: cannot be assigned a fixed value, but when the name of such an attribute
1452: appears this indicates that this element type must have a valid value for the
1.2 cvs 1453: attribute. For the other attribute types, the fixed value is indicated by a
1.1 cvs 1454: signed integer (numeric attributes), a character string between apostrophes
1.18 cvs 1455: (textual attributes) or the name of a value (enumeration attributes).</p>
1.30 ! cvs 1456:
! 1457: <p>Fixed-value attributes can either be <a href="#sectc325">global</a> or
! 1458: local to the element type for which they are fixed, but they must be declared
! 1459: before they are used.</p>
! 1460: <pre> FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 1461: FixedAttr = AttrID [ FixedOrModifVal ] .
1462: FixedOrModifVal = [ '?' ] '=' FixedValue .
1463: FixedValue = [ '-' ] NumValue / TextVal / AttrVal .
1464: NumValue = NUMBER .
1.18 cvs 1465: TextVal = STRING .</pre>
1466: </div>
1.1 cvs 1467:
1.18 cvs 1468: <div class="subsection">
1.30 ! cvs 1469: <h3><a name="sectc328">Structure definitions</a></h3>
1.1 cvs 1470:
1.30 ! cvs 1471: <p>The structure of an element type can be a simple base type or a constructed
1.18 cvs 1472: type.</p>
1.30 ! cvs 1473:
! 1474: <p>For constructed types, it is frequently the case that similar structures
1.1 cvs 1475: appear in many places in a document. For example the contents of the
1476: abstract, of the introduction, and of a section can have the same structure,
1477: that of a sequence of paragraphs. In this case, a single, common structure
1478: can be defined (the paragraph sequence in this example), and the schema is
1479: written to indicate that each element type possesses this structure, as
1.18 cvs 1480: follows:</p>
1481: <pre> Abstract = Paragraph_sequence;
1.1 cvs 1482: Introduction = Paragraph_sequence;
1.18 cvs 1483: Section_contents = Paragraph_sequence;</pre>
1.30 ! cvs 1484:
! 1485: <p>The equals sign means ``has the same structure as''.</p>
! 1486:
! 1487: <p>If the element type defined is a simple base type, this is indicated by one
! 1488: of the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>, <tt>SYMBOL</tt>, or
1.18 cvs 1489: <tt>PICTURE</tt>. If some local attributes must be associated with a base
1.1 cvs 1490: type, the keyword of the base type is followed by the declaration of the local
1.18 cvs 1491: attributes using the syntax <a href="#sectc327">presented above.</a></p>
1.30 ! cvs 1492:
! 1493: <p>In the case of an open choice, the type is indicated by the keyword
1.18 cvs 1494: <tt>UNIT</tt> for units or the keyword <tt>NATURE</tt> for objects having a
1495: structure defined by any other schema.</p>
1.30 ! cvs 1496:
! 1497: <p>A unit represents one of the two following categories:</p>
1.18 cvs 1498: <ul>
1.30 ! cvs 1499: <li>a base type: text, graphical element, symbol, picture,</li>
! 1500: <li>an element whose type is chosen from among the types defined as units in
! 1501: the <tt>UNITS</tt> section of the document's structure schema. It can
! 1502: also be chosen from among the types defined as <a
! 1503: href="#sectd3132">units</a> in the <a href="#sectc3212"><tt>UNITS</tt>
! 1504: section</a> of the structure schemas that defines the ancestors of the
! 1505: element to which the rule is applied.</li>
1.18 cvs 1506: </ul>
1.30 ! cvs 1507:
! 1508: <p>Before the creation of an element defined as a unit, Thot asks the user to
1.18 cvs 1509: choose between the categories of elements.</p>
1.30 ! cvs 1510:
! 1511: <p>Thus, the contents of a paragraph can be specified as a sequence of units,
1.1 cvs 1512: which will permit the inclusion in the paragraphs of character strings,
1513: symbols, and various elements, such as cross-references, if these are defined
1.18 cvs 1514: as units.</p>
1.30 ! cvs 1515:
! 1516: <p>A schema object (keyword <tt>NATURE</tt>) represents an object defined by a
1.1 cvs 1517: structure schema freely chosen from among the available schemas; in the case
1518: the element type is defined by the first rule (the root rule) of the chosen
1.18 cvs 1519: schema.</p>
1.30 ! cvs 1520:
! 1521: <p>If the element type defined is a constructed type, the list, aggregate,
1.1 cvs 1522: choice, and reference constructors are used. In this case the definition
1523: begins with a keyword identifying the constructor. This keyword is followed
1.18 cvs 1524: by a syntax specific to each constructor.</p>
1.30 ! cvs 1525:
! 1526: <p>The local attribute definitions appear after the name of the element type
1.18 cvs 1527: being defined, if this element type has <a href="#sectc327">local
1528: attributes</a>.</p>
1529: <pre> Definition = BaseType [ LocAttrSeq ] / Constr / Element .
1.1 cvs 1530: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' / 'PICTURE' /
1531: 'UNIT' / 'NATURE' .
1532: Element = ElemID [ ExtOrDef ] .
1533: ExtOrDef = 'EXTERN' / 'INCLUDED' /
1534: [ LocAttrSeq ] '=' Definition .
1535: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
1536: '(' DefWithAttr ')' /
1537: 'BEGIN' DefOptSeq 'END' /
1538: 'AGGREGATE' DefOptSeq 'END' /
1539: 'CASE' 'OF' DefSeq 'END' /
1540: 'REFERENCE' '(' RefType ')' /
1.18 cvs 1541: 'PAIR' .</pre>
1.1 cvs 1542:
1.18 cvs 1543: <div class="subsubsection">
1.30 ! cvs 1544: <h4><a name="sectd3281">List</a></h4>
1.1 cvs 1545:
1.30 ! cvs 1546: <p>The list constructor permits the definition of an element type composed of
! 1547: a list of elements, all of the same type. A list definition begins with the
1.18 cvs 1548: <tt>LIST</tt> keyword followed by an optional range, the keyword <tt>OF</tt>,
1.1 cvs 1549: and the definition, between parentheses, of the element type which must
1550: compose the list. The optional range is composed of the minimum and maximum
1551: number of elements for the list separated by two periods and enclosed by
1552: brackets. If the range is not present, the number of list elements is
1553: unconstrained. When only one of the two bounds of the range is unconstrained,
1554: it is represented by a star ('*') character. Even when both bounds are
1.18 cvs 1555: unconstrained, they can be specified by <tt>[*..*]</tt>, but it is simpler not
1556: to specify any bound.</p>
1557: <pre> 'LIST' [ '[' min '..' max ']' ]
1.1 cvs 1558: 'OF' '(' DefWithAttr ')'
1559: min = Integer / '*' .
1560: max = Integer / '*' .
1.18 cvs 1561: Integer = NUMBER .</pre>
1.30 ! cvs 1562:
! 1563: <p>Before the document is edited, Thot creates the minimum number of elements
! 1564: for the list. If no minimum was given, it creates a single element. If a
! 1565: maximum number of elements is given and that number is attained, the editor
! 1566: refuses to create new elements for the list.</p>
! 1567:
! 1568: <blockquote class="example">
! 1569: <p><strong>Example:</strong></p>
! 1570:
! 1571: <p>The following two instructions define the body of a document as a
! 1572: sequence of at least two chapters and the contents of a section as a
! 1573: sequence of paragraphs. A single paragraph can be the entire contents of a
! 1574: section.</p>
! 1575: <pre>Body = LIST [2..*] OF (Chapter);
1.18 cvs 1576: Section_contents = LIST OF (Paragraph);</pre>
1577: </blockquote>
1578: </div>
1.1 cvs 1579:
1.18 cvs 1580: <div class="subsubsection">
1.30 ! cvs 1581: <h4><a name="sectd3282">Aggregate</a></h4>
1.1 cvs 1582:
1.30 ! cvs 1583: <p>The aggregate constructor is used to define an element type as a collection
! 1584: of sub-elements, each having a fixed type. The collection may be ordered or
1.1 cvs 1585: unordered. The elements composing the collection are called
1.18 cvs 1586: <em>components</em>. In the definition of an aggregate, a keyword indicates
1587: whether or not the aggregate is ordered: <tt>BEGIN</tt> for an ordered
1588: aggregate, <tt>AGGREGATE</tt> for an unordered aggregate. This keyword is
1.1 cvs 1589: followed by the list of component type definitions which is terminated by the
1.18 cvs 1590: <tt>END</tt> keyword. The component type definitions are separated by
1591: commas.</p>
1.30 ! cvs 1592:
! 1593: <p>Before creating an aggregate, the Thot editor creates all the aggregate's
1.1 cvs 1594: components in the order they appear in the structure schema, even for
1595: unordered aggregates. However, unlike ordered aggregates, the components of
1596: an unordered aggregate may be rearranged using operations of the Thot editor.
1597: The exceptions to the rule are any components whose name was preceded by a
1598: question mark character ('?'). These components, which are optional, can be
1599: created by explicit request, possibly at the time the aggregate is created,
1.18 cvs 1600: but they are not created automatically <em>prior</em> to the creation of the
1601: aggregate.</p>
1602: <pre> 'BEGIN' DefOptSeq 'END'
1.30 ! cvs 1603: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.18 cvs 1604: DefOpt = [ '?' ] DefWithAttr .</pre>
1.30 ! cvs 1605:
1.18 cvs 1606: <blockquote class="example">
1.30 ! cvs 1607: <p><strong>Example:</strong></p>
! 1608:
! 1609: <p>In a bilingual document, each paragraph has an English version and a
! 1610: French version. In certain cases, the translator wants to add a marginal
! 1611: note, but this note is present in very few paragraphs. Thus, it must not be
! 1612: created systematically for every paragraph. A bilingual paragraph of this
! 1613: type is declared:</p>
! 1614: <pre>Bilingual_paragraph = BEGIN
1.1 cvs 1615: French_paragraph = TEXT;
1616: English_paragraph = TEXT;
1617: ? Note = TEXT;
1.18 cvs 1618: END;</pre>
1619: </blockquote>
1620: </div>
1.1 cvs 1621:
1.18 cvs 1622: <div class="subsubsection">
1.30 ! cvs 1623: <h4><a name="sectd3283">Choice</a></h4>
1.1 cvs 1624:
1.30 ! cvs 1625: <p>The choice constructor permits the definition of an element type which is
1.18 cvs 1626: chosen from among a set of possible types. The keywords <tt>CASE</tt> and
1627: <tt>OF</tt> are followed by a list of definitions of possible types, which are
1628: separated by semicolons and terminated by the <tt>END</tt> keyword.</p>
1629: <pre> 'CASE' 'OF' DefSeq 'END'
1.30 ! cvs 1630: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .</pre>
! 1631:
! 1632: <p>Before the creation of an element defined as a choice, the Thot editor
1.1 cvs 1633: presents the list of possible types for the element to the user. The user has
1.18 cvs 1634: only to select the element type that s/he wants to create from this list.</p>
1.30 ! cvs 1635:
! 1636: <p>The order of the type declarations is important. It determines the order
! 1637: of the list presented to the user before the creation of the element. Also,
! 1638: when a Choice element is being created automatically, the first type in the
! 1639: list is used. In fact, using the Thot editor, when an empty Choice element is
1.1 cvs 1640: selected, it is possible to select this element and to enter its text from
1641: keyboard. In this case, the editor uses the first element type which can
1.18 cvs 1642: contain an atom of the character string type.</p>
1.30 ! cvs 1643:
! 1644: <p>The two special cases of the choice constructor, the <a
1.18 cvs 1645: href="#sectc328"><em>schema</em></a> and the <a
1646: href="#sectc3212"><em>unit</em></a> are discussed elsewhere.</p>
1.30 ! cvs 1647:
1.18 cvs 1648: <blockquote class="example">
1.30 ! cvs 1649: <p><strong>Example:</strong></p>
! 1650:
! 1651: <p>It is common in documents to treat a variety of objects as if they were
! 1652: ordinary paragraphs. Thus, a ``Paragraph'' might actually be composed of a
! 1653: block of text (an ordinary paragraph), or a mathematical formula whose
! 1654: structure is defined by another structure schema named Math, or a table,
! 1655: also defined by another structure schema. Here is a definition of such a
! 1656: paragraph:</p>
! 1657: <pre>Paragraph = CASE OF
1.1 cvs 1658: Simple_text = TEXT;
1659: Formula = Math;
1660: Table_para = Table;
1.18 cvs 1661: END;</pre>
1662: </blockquote>
1663: </div>
1.1 cvs 1664:
1.18 cvs 1665: <div class="subsubsection">
1.30 ! cvs 1666: <h4><a name="sectd3284">Reference</a></h4>
1.1 cvs 1667:
1.30 ! cvs 1668: <p>Like all elements in Thot, references are typed. An element type defined
! 1669: as a reference is a cross-reference to an element of some other given type.
! 1670: The keyword <tt>REFERENCE</tt> is followed by the name of a type enclosed in
1.1 cvs 1671: parentheses. When the type which is being cross-referenced is defined in
1672: another structure schema, the type name is itself followed by the name of the
1.18 cvs 1673: external structure schema in which it is defined.</p>
1.30 ! cvs 1674:
! 1675: <p>When the designated element type is a <a href="#sectd3285">mark pair</a>,
! 1676: it can be preceded by a <tt>FIRST</tt> or <tt>SECOND</tt> keyword. These
1.18 cvs 1677: keywords indicate whether the reference points to the first or second mark of
1678: the pair. If the reference points to a pair and neither of these two keywords
1679: is present, the reference is considered to point to the first mark of the
1680: pair.</p>
1.30 ! cvs 1681:
! 1682: <p>There is an exception to the principle of typed references: it is possible
! 1683: to define a reference which designates an element of any type, which can
! 1684: either be in the same document or another document. In this case, it suffices
! 1685: to put the keyword <tt>ANY</tt> in the parentheses which indicate the
! 1686: referenced element type.</p>
1.18 cvs 1687: <pre> 'REFERENCE' '(' RefType ')'
1688: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .</pre>
1.30 ! cvs 1689:
! 1690: <p>When defining an inclusion, the <tt>REFERENCE</tt> keyword is not used.
1.1 cvs 1691: Inclusions with complete expansion are not declared as such in the structure
1692: schemas, since any element defined in a structure schema can be replaced by an
1693: element of the same type. Instead, inclusions without expansion or with
1694: partial expansion must be declared explicitly whenever they will include a
1695: complete object ( and not a part of an object). In this case, the object type
1696: to be included (that is, the name of its structure schema) is followed by a
1.18 cvs 1697: keyword: <tt>EXTERN</tt> for inclusion without expansion and <tt>INCLUDED</tt>
1698: for partial expansion.</p>
1.30 ! cvs 1699:
! 1700: <p>Before creating a cross-reference or an inclusion, the Thot editor asks the
1.1 cvs 1701: user to choose, from the document images displayed, the referenced or included
1.18 cvs 1702: element.</p>
1.30 ! cvs 1703:
1.18 cvs 1704: <blockquote class="example">
1.30 ! cvs 1705: <p><strong>Example:</strong></p>
! 1706:
! 1707: <p>If the types Note and Section are defined in the Article structure
! 1708: schema, it is possible to define, in the same structure schema, a reference
! 1709: to a note and a reference to a section in this manner:</p>
! 1710: <pre>Ref_note = REFERENCE (Note);
1.18 cvs 1711: Ref_section = REFERENCE (Section);</pre>
1.30 ! cvs 1712:
! 1713: <p>It is also possible to define the generic structure of a collection of
! 1714: articles, which include (with partial expansion) objects of the Article
! 1715: class and which possess an introduction which may include cross-references
! 1716: to sections of the included articles. In the Collection structure schema,
! 1717: the definitions are:</p>
! 1718: <pre>Collection = BEGIN
1.6 cvs 1719: Collection_title = TEXT;
1720: Introduction = LIST OF (Elem = CASE OF
1.1 cvs 1721: TEXT;
1722: Ref_sect;
1723: END);
1.6 cvs 1724: Body = LIST OF (Article INCLUDED);
1725: END;
1.18 cvs 1726: Ref_sect = REFERENCE (Section (Article));</pre>
1.30 ! cvs 1727:
! 1728: <p>Here we define a Folder document class which has a title and includes
! 1729: documents of different types, particularly Folders:</p>
! 1730: <pre>Folder = BEGIN
1.6 cvs 1731: Folder_title = TEXT;
1732: Folder_contents = LIST OF (Document);
1733: END;
1.1 cvs 1734:
1735: Document = CASE OF
1736: Article EXTERN;
1737: Collection EXTERN;
1738: Folder EXTERN;
1.18 cvs 1739: END;</pre>
1.30 ! cvs 1740:
! 1741: <p>Under this definition, Folder represents either an aggregate which
! 1742: contains a folder title and the list of included documents or an included
! 1743: folder. To resolve this ambiguity, in the P language, the placement of a
! 1744: star character in front of the type name (here, Folder) indicates an
! 1745: included document.</p>
1.18 cvs 1746: </blockquote>
1747: </div>
1.1 cvs 1748:
1.18 cvs 1749: <div class="subsubsection">
1.30 ! cvs 1750: <h4><a name="sectd3285">Mark pairs</a></h4>
1.1 cvs 1751:
1.30 ! cvs 1752: <p>Like other elements, mark pairs are typed. The two marks of the pair have
! 1753: the same type, but there exist two predefined subtypes which apply to all mark
1.18 cvs 1754: pairs: the first mark of the pair (called <tt>First</tt> in the P and T
1755: languages) and the second mark (called <tt>Second</tt>).</p>
1.30 ! cvs 1756:
! 1757: <p>In the S language, a mark pair is noted simply by the <tt>PAIR</tt>
1.18 cvs 1758: keyword.</p>
1.30 ! cvs 1759:
! 1760: <p>In the Thot editor, marks are always moved or destroyed together. The two
1.1 cvs 1761: marks of a pair have the same identifier, unique within the document, which
1.18 cvs 1762: permits intertwining mark pairs without risk of ambiguity.</p>
1763: </div>
1764: </div>
1.1 cvs 1765:
1.18 cvs 1766: <div class="subsection">
1.30 ! cvs 1767: <h3><a name="sectc329">Imports</a></h3>
1.1 cvs 1768:
1.30 ! cvs 1769: <p>Because of schema constructors, it is possible, before editing a document,
! 1770: to use classes defined by other structure schemas whenever they are needed. It
! 1771: is also possible to assign specific document classes to certain element types.
! 1772: In this case, these classes are simply designated by their name. In fact, if
! 1773: a type name is not defined in the structure schema, it is assumed that it
1.18 cvs 1774: specifies a structure defined by another structure schema.</p>
1.30 ! cvs 1775:
1.18 cvs 1776: <blockquote class="example">
1.30 ! cvs 1777: <p><strong>Example:</strong></p>
! 1778:
! 1779: <p>If the types Math and Table don't appear in the left part of a structure
! 1780: rule in the schema, the following two rules indicate that a formula has the
! 1781: structure of an object defined by the structure schema Math and that a table
! 1782: element has the structure of an object defined by the Table schema.</p>
! 1783: <pre>Formula = Math;
1.18 cvs 1784: Table_elem = Table;</pre>
1785: </blockquote>
1786: </div>
1787:
1788: <div class="subsection">
1.30 ! cvs 1789: <h3><a name="sectc3210">Extension rules</a></h3>
1.18 cvs 1790:
1.30 ! cvs 1791: <p>The <tt>EXTENS</tt> section, which can only appear in an extension schema,
1.1 cvs 1792: defines complements to the rules in the primary schema (i.e. the structure
1793: schema to which the extension schema will be applied). More precisely, this
1794: section permits the addition to an existing type of local attributes,
1.18 cvs 1795: extensions, restrictions and fixed-value attributes.</p>
1.30 ! cvs 1796:
! 1797: <p>These additions can be applied to the root rule of the primary schema,
1.18 cvs 1798: designated by the keyword <tt>Root</tt>, or to any other explicitly named
1799: rule.</p>
1.30 ! cvs 1800:
! 1801: <p>Extension rules are separated from each other by a semicolon and each
1.18 cvs 1802: extension rule has the same syntax as a <a href="#sectc327">structure
1803: rule</a>, but the part which defines the constructor is absent.</p>
1.30 ! cvs 1804: <pre> ExtenRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.6 cvs 1805: ExtensRule = RootOrElem [ LocAttrSeq ]
1806: [ '+' '(' ExtensionSeq ')' ]
1807: [ '-' '(' RestrictSeq ')' ]
1808: [ 'WITH' FixedAttrSeq ] .
1.18 cvs 1809: RootOrElem = 'Root' / ElemID .</pre>
1810: </div>
1.1 cvs 1811:
1.18 cvs 1812: <div class="subsection">
1.30 ! cvs 1813: <h3><a name="sectc3211">Associated elements</a></h3>
1.1 cvs 1814:
1.30 ! cvs 1815: <p>If associated elements are necessary, they must be declared in a specific
1.18 cvs 1816: section of the structure schema, introduced by the keyword <tt>ASSOC</tt>.
1.1 cvs 1817: Each associated element type is specified like any other structured element.
1818: However, these types must not appear in any other element types of the schema,
1.18 cvs 1819: except in <tt>REFERENCE</tt> rules.</p>
1820: </div>
1.1 cvs 1821:
1.18 cvs 1822: <div class="subsection">
1.30 ! cvs 1823: <h3><a name="sectc3212">Units</a></h3>
! 1824:
! 1825: <p>The <tt>UNITS</tt> section of the structure schema contains the
! 1826: declarations of the element types which can be used in the external objects
! 1827: making up parts of the document or in objects of the class defined by the
! 1828: schema. As with associated elements, these element types are defined just
! 1829: like other structured element types. They can be used in the other element
! 1830: types of the schema, but they can also be used in any other rule of the
! 1831: schema.</p>
! 1832:
! 1833: <blockquote class="example">
! 1834: <p><strong>Example:</strong></p>
1.1 cvs 1835:
1.30 ! cvs 1836: <p>If references to notes are declared as units:</p>
! 1837: <pre>UNITS
1.18 cvs 1838: Ref_note = REFERENCE (Note);</pre>
1.30 ! cvs 1839:
! 1840: <p>then it is possible to use references to notes in a cell of a table, even
! 1841: when <tt>Table</tt> is an external structure schema. The <tt>Table</tt>
! 1842: schema must declare a cell to be a sequence of units, which can then be base
! 1843: element types (text, for example) or references to notes in the
! 1844: document.</p>
! 1845: <pre>Cell = LIST OF (UNITS);</pre>
1.18 cvs 1846: </blockquote>
1847: </div>
1.1 cvs 1848:
1.18 cvs 1849: <div class="subsection">
1.30 ! cvs 1850: <h3><a name="sectc3213">Skeleton elements</a></h3>
1.1 cvs 1851:
1.30 ! cvs 1852: <p>When editing a document which contains or must contain external references
! 1853: to several other documents, it may be necessary to load a large number of
1.1 cvs 1854: documents, simply to see the parts designated by the external references of
1855: the document while editing, or to access the source of included elements. In
1856: this case, the external documents are not modified and it is only necessary to
1857: see the elements of these documents which could be referenced. Because of
1858: this, the editor will suggest that the documents be loaded in ``skeleton''
1859: form. This form contains only the elements of the document explicitly
1.18 cvs 1860: mentioned in the <tt>EXPORT</tt> section of their structure schema and, for
1.1 cvs 1861: these elements, only the part of the contents specified in that section. This
1862: form has the advantage of being very compact, thus requiring very few
1863: resources from the editor. This is also the skeleton form which constitutes
1.18 cvs 1864: the expanded form of <a href="#inclusion">inclusions</a> with partial
1865: expansion.</p>
1.30 ! cvs 1866:
! 1867: <p>Skeleton elements must be declared explicitly in the <tt>EXPORT</tt>
! 1868: section of the structure schema that defines them. This section begins with
! 1869: the keyword <tt>EXPORT</tt> followed by a comma-separated list of the element
1.1 cvs 1870: types which must appear in the skeleton form and ending with a semicolon.
1.18 cvs 1871: These types must have been previously declared in the schema.</p>
1.30 ! cvs 1872:
! 1873: <p>For each skeleton element type, the part of the contents which is loaded by
1.1 cvs 1874: the editor, and therefore displayable, can be specified by putting the keyword
1.18 cvs 1875: <tt>WITH</tt> and the name of the contained element type to be loaded after
1.1 cvs 1876: the name of the skeleton element type. In this case only that named element,
1877: among all the elements contained in the exportable element type, will be
1.18 cvs 1878: loaded. If the <tt>WITH</tt> is absent, the entire contents of the skeleton
1.1 cvs 1879: element will be loaded by the editor. If instead, it is better that the
1880: skeleton form not load the contents of a particular element type, the keyword
1.18 cvs 1881: <tt>WITH</tt> must be followed by the word <tt>Nothing</tt>.</p>
1882: <pre> [ 'EXPORT' SkeletonSeq ]
1.1 cvs 1883:
1.30 ! cvs 1884: SkeletonSeq = SkelElem < ',' SkelElem > ';' .
1.1 cvs 1885: SkelElem = ElemID [ 'WITH' Contents ] .
1.18 cvs 1886: Contents = 'Nothing' / ElemID [ ExtStruct ] .</pre>
1.30 ! cvs 1887:
1.18 cvs 1888: <blockquote class="example">
1.30 ! cvs 1889: <p><strong>Example:</strong></p>
! 1890:
! 1891: <p>Suppose that, in documents of the article class, the element types
! 1892: Article_title, Figure, Section, Paragraph, and Biblio should appear in the
! 1893: skeleton form in order to make it easier to create external references to
! 1894: them from other documents. When loading an article in its skeleton form,
! 1895: all of these element types will be loaded except for paragraphs, but only
! 1896: the article title will be loaded in its entirety. For figures, the caption
! 1897: will be loaded, while for sections, the title will be loaded, and for
! 1898: bibliographic entries, only the title that they contain will be loaded.
! 1899: Note that bibliographic elements are defined in another structure schema,
! 1900: RefBib. To produce this result, the following declarations should be placed
! 1901: in the Article structure schema:</p>
! 1902: <pre>EXPORT
1.1 cvs 1903: Article_title,
1.5 cvs 1904: Figure With Caption,
1.1 cvs 1905: Section With Section_title,
1906: Paragraph With Nothing,
1.18 cvs 1907: Biblio With Biblio_title(RefBib);</pre>
1908: </blockquote>
1909: </div>
1.1 cvs 1910:
1.18 cvs 1911: <div class="subsection">
1.30 ! cvs 1912: <h3><a name="sectc3214">Exceptions</a></h3>
1.1 cvs 1913:
1.30 ! cvs 1914: <p>The behavior of the Thot editor and the actions that it performs are
1.1 cvs 1915: determined by the structure schemas. These actions are applied to all
1916: document and object types in accordance with their generic structure. For
1917: certain object types, such as tables and graphics, these actions are not
1918: sufficient or are poorly adapted and some special actions must be added to or
1919: substituted for certain standard actions. These special actions are called
1.18 cvs 1920: <em>exceptions</em>.</p>
1.30 ! cvs 1921:
! 1922: <p>Exceptions only inhibit or modify certain standard actions, but they can be
1.18 cvs 1923: used freely in every structure schema.</p>
1.30 ! cvs 1924:
! 1925: <p>Each structure schema can contain a section defining exceptions. It begins
1.18 cvs 1926: with the keyword <tt>EXCEPT</tt> and is composed of a sequence of exception
1.1 cvs 1927: declarations, separated by semicolons. Each declaration of an exception
1928: begins with the name of an element type or attribute followed by a colon. This
1929: indicates the element type or attribute to which the following exceptions
1.18 cvs 1930: apply. When the given element type name is a <a href="#sectd3285">mark
1931: pair</a>, and only in this case, the type name can be preceded by the keyword
1932: <tt>First</tt> or <tt>Second</tt>, to indicate if the exceptions which follow
1.1 cvs 1933: are associated with the first mark of the pair or the second. In the absence
1.18 cvs 1934: of this keyword, the first mark is used.</p>
1.30 ! cvs 1935:
! 1936: <p>When placed in an <a href="#sectc322">extension schema</a>, the keyword
1.18 cvs 1937: <tt>EXTERN</tt> indicates that the type name which follows is found in the
1.1 cvs 1938: principal schema (the schema being extended by the extension schema). The
1.18 cvs 1939: exceptions are indicated by a name. They are separated by semicolons.</p>
1940: <pre> [ 'EXCEPT' ExceptSeq ]
1.1 cvs 1941:
1.30 ! cvs 1942: ExceptSeq = Except ';' < Except ';' > .
1.1 cvs 1943: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr
1944: ':' ExcValSeq .
1945: ExcTypeOrAttr = ElemID / AttrID .
1.30 ! cvs 1946: ExcValSeq = ExcValue < ',' ExcValue > .
1.19 cvs 1947: ExcValue ='NoCut' / 'NoCreate' / 'NoHMove' /
1948: 'NoVMove' / 'NoHResize' / 'NoVResize' /
1949: 'NoMove' / 'NoResize' / 'MoveResize' /
1950: 'NewWidth' / 'NewHeight' / 'NewHPos' /
1951: 'NewVPos' / 'Invisible' /
1.28 cvs 1952: 'NoSelect' / 'NoSpellCheck' /
1.1 cvs 1953: 'Hidden' / 'ActiveRef' /
1954: 'ImportLine' / 'ImportParagraph' /
1955: 'NoPaginate' / 'ParagraphBreak' /
1.19 cvs 1956: 'PageBreak' / 'PageBreakAllowed' / 'PageBreakPlace' /
1957: 'PageBreakRepetition' / 'PageBreakRepBefore' /
1.9 cvs 1958: 'HighlightChildren' / 'ExtendedSelection' /
1.29 cvs 1959: 'ReturnCreateNL' / 'ReturnCreateWithin' /
1960: 'IsDraw' / 'IsTable' /
1.19 cvs 1961: 'IsRow' / 'IsColHead' / 'IsCell' /
1962: 'NewPercentWidth' / 'ColRef' / 'ColSpan' /
1963: 'RowSpan' / 'SaveDocument' / 'Shadow' .</pre>
1.30 ! cvs 1964:
! 1965: <p>The following are the available exceptions:</p>
1.18 cvs 1966: <dl>
1.30 ! cvs 1967: <dt><tt>NoCut</tt></dt>
! 1968: <dd>This exception can only be applied to element types. Elements of a
! 1969: type to which this exception is applied cannot be deleted by the
! 1970: editor.</dd>
! 1971: <dt><tt>NoCreate</tt></dt>
! 1972: <dd>This exception can only be applied to element types. Elements of a
! 1973: type to which this exception is applied cannot be created by ordinary
! 1974: commands for creating new elements. These elements are usually created
! 1975: by special actions associated with other exceptions.</dd>
! 1976: <dt><tt>NoHMove</tt></dt>
! 1977: <dd>This exception can only be applied to element types. Elements of a
! 1978: type to which this exception is applied cannot be moved horizontally
! 1979: with the mouse. Their children elements cannot be moved either.</dd>
! 1980: <dt><tt>NoVMove</tt></dt>
! 1981: <dd>This exception can only be applied to element types. Elements of a
! 1982: type to which this exception is applied cannot be moved vertically with
! 1983: the mouse. Their children elements cannot be moved either.</dd>
! 1984: <dt><tt>NoMove</tt></dt>
! 1985: <dd>This exception can only be applied to element types. Elements of a
! 1986: type to which this exception is applied cannot be moved in any direction
! 1987: with the mouse. Their children elements cannot be moved either.</dd>
! 1988: <dt><tt>NoHResize</tt></dt>
! 1989: <dd>This exception can only be applied to element types. Elements of a
! 1990: type to which this exception is applied cannot be resized horizontally
! 1991: with the mouse. Their children elements cannot be resized either.</dd>
! 1992: <dt><tt>NoVResize</tt></dt>
! 1993: <dd>This exception can only be applied to element types. Elements of a
! 1994: type to which this exception is applied cannot be resized vertically
! 1995: with the mouse. Their children elements cannot be resized either.</dd>
! 1996: <dt><tt>NoResize</tt></dt>
! 1997: <dd>This exception can only be applied to element types. Elements of a
! 1998: type to which this exception is applied cannot be resized in any
! 1999: direction with the mouse. Their children elements cannot be resized
! 2000: either.</dd>
! 2001: <dt><tt>MoveResize</tt></dt>
! 2002: <dd>This exception can only be applied to element types. Elements of a
! 2003: type to which this exception is applied can be moved and resized in any
! 2004: direction with the mouse, even if one of their ancestor element has an
! 2005: exception that prevents moving or resizing. Their children elements can
! 2006: also be resized or moved.</dd>
! 2007: <dt><tt>NewWidth</tt></dt>
! 2008: <dd>This exception can only be applied to numeric attributes. If the
! 2009: width of an element which has this attribute is modified with the mouse,
! 2010: the value of the new width will be assigned to the attribute.</dd>
! 2011: <dt><tt>NewHeight</tt></dt>
! 2012: <dd>This exception can only be applied to numeric attributes. If the
! 2013: height of an element which has this attribute is modified with the
! 2014: mouse, the value of the new height will be assigned to the
! 2015: attribute.</dd>
! 2016: <dt><tt>NewHPos</tt></dt>
! 2017: <dd>This exception can only be applied to numeric attributes. If the
! 2018: horizontal position of an element which has this attribute is modified
! 2019: with the mouse, the value of the new horizontal position will be
! 2020: assigned to the attribute.</dd>
! 2021: <dt><tt>NewVPos</tt></dt>
! 2022: <dd>This exception can only be applied to numeric attributes. If the
! 2023: vertical position of an element which has this attribute is modified
! 2024: with the mouse, the value of the new vertical position will be assigned
! 2025: to the attribute.</dd>
! 2026: <dt><tt>Invisible</tt></dt>
! 2027: <dd>This exception can only be applied to attributes, but can be applied
! 2028: to all attribute types. It indicates that the attribute must not be
! 2029: seen by the user and that its value must not be changed directly. This
! 2030: exception is usually used when another exception manipulates the value
! 2031: of an attribute.</dd>
! 2032: <dt><tt>NoSelect</tt></dt>
! 2033: <dd>This exception can only be applied to element types. Elements of a
! 2034: type to which this exception is applied cannot be selected directly
! 2035: with the mouse, but they can be selected by other methods provided by
! 2036: the editor.</dd>
! 2037: <dt>NoSpellCheck</dt>
! 2038: <dd>This exception can only be applied to element types. Elements of a
! 2039: type to which this exception is applied are not taken into account by
! 2040: the spell checker.</dd>
! 2041: <dt><tt>Hidden</tt></dt>
! 2042: <dd>This exception can only be applied to element types. It indicates
! 2043: that elements of this type, although present in the document's
! 2044: structure, must not be shown to the user of the editor. In particular,
! 2045: the creation menus must not propose this type and the selection message
! 2046: must not pick it.</dd>
! 2047: <dt><tt>ActiveRef</tt></dt>
! 2048: <dd>This exception can only be applied to attributes of the reference
! 2049: type. It indicates that when the user of the editor makes a double
! 2050: click on an element which possesses a reference attribute having this
! 2051: exception, the element designated by the reference attribute will be
! 2052: selected.</dd>
! 2053: <dt><tt>ImportLine</tt></dt>
! 2054: <dd>This exception can only be applied to element types. It indicates
! 2055: that elements of this type should receive the content of imported text
! 2056: files. An element is created for each line of the imported file. A
! 2057: structure schema cannot contain several exceptions <tt>ImportLine</tt>
! 2058: and, if it contains one, it should not contain any exception
! 2059: <tt>ImportParagraph</tt>.</dd>
! 2060: <dt><tt>ImportParagraph</tt></dt>
! 2061: <dd>This exception can only be applied to element types. It indicates
! 2062: that elements of this type should receive the content of imported text
! 2063: files. An element is created for each paragraph of the imported file.
! 2064: A paragraph is a sequence of lines without any empty line. A structure
! 2065: schema cannot contain several exceptions <tt>ImportParagraph</tt> and,
! 2066: if it contains one, it should not contain any exception
! 2067: <tt>ImportLine</tt>.</dd>
! 2068: <dt><tt>NoPaginate</tt></dt>
! 2069: <dd>This exception can only be applied to the root element, i.e. the name
! 2070: that appear after the keyword <tt>STRUCTURE</tt> at the beginning of the
! 2071: structure schema. It indicates that the editor should not allow the
! 2072: user to paginate documents of that type.</dd>
! 2073: <dt><tt>ParagraphBreak</tt></dt>
! 2074: <dd>This exception can only be applied to element types. When the caret
! 2075: is within an element of a type to which this exception is applied, it is
! 2076: that element that will be split when the user hits the Return key.</dd>
! 2077: <dt><tt>ReturnCreateNL</tt></dt>
! 2078: <dd>This exception can only be applied to element types. When the caret
! 2079: is within an element of a type to which this exception is applied, the
! 2080: Return key simply inserts a New line character (code \212) at the
! 2081: current position. The Return key does not create a new element; it does
! 2082: not split the current element either.</dd>
! 2083: <dt><tt>ReturnCreateWithin</tt></dt>
! 2084: <dd>This exception can only be applied to element types. When the caret
! 2085: is within an element of a type to which this exception is applied, the
! 2086: Return key will create a new element within that element, not a sibling
! 2087: after that element.</dd>
! 2088: <dt><tt>HighlightChildren</tt></dt>
! 2089: <dd>This exception can only be applied to element types. Elements of a
! 2090: type to which this exception is applied are not highlighted themselves
! 2091: when they are selected, but all their children are highlighted
! 2092: instead.</dd>
! 2093: <dt><tt>ExtendedSelection</tt></dt>
! 2094: <dd>This exception can only be applied to element types. The selection
! 2095: extension command (middle button of the mouse) only add the clicked
! 2096: element (if it has that exception) to the current selection, without
! 2097: selecting other elements between the current selection and the clicked
! 2098: element.</dd>
! 2099: <dt>IsDraw, IsTable, IsColHead, IsRow, IsCell</dt>
! 2100: <dd>These exceptions can only be applied to element types. Elements of a
! 2101: type to which these exceptions are applied are identified as Draws,
! 2102: Tables, Colheads, Rows or Cells and specific processing are applied to
! 2103: them.</dd>
! 2104: <dt>ColRef</dt>
! 2105: <dd>This exception can only be applied to attributes of the reference
! 2106: type. It indicates that this attribute refers to the column head (see
! 2107: exception IsColHead) which the element belongs to.</dd>
! 2108: <dt>ColSpan, RowSpan</dt>
! 2109: <dd>These exceptions can only be applied to numeric attributes of cells.
! 2110: They indicate that attribute values give how many columns or rows the
! 2111: element spans.</dd>
! 2112: <dt>Shadow</dt>
! 2113: <dd>This exception can only be applied to element types. Text of elements
! 2114: of a type to which this exception is applied are displayed and printed
! 2115: as a set of stars ('*').</dd>
1.18 cvs 2116: </dl>
1.30 ! cvs 2117:
1.18 cvs 2118: <blockquote class="example">
1.30 ! cvs 2119: <p><strong>Example:</strong></p>
! 2120:
! 2121: <p>Consider a structure schema for object-style graphics which defines the
! 2122: Graphic_object element type with the associated Height and Weight numeric
! 2123: attributes. Suppose that we want documents of this class to have the
! 2124: following qualities:</p>
! 2125: <ul>
! 2126: <li>Whenever the width or height of an object is changed using the mouse,
! 2127: the new values are stored in the object's Width and Height
! 2128: attributes.</li>
! 2129: <li>The user should not be able to change the values of the Width and
! 2130: Height attributes via the Attributes menu of the Thot editor.</li>
! 2131: </ul>
! 2132:
! 2133: <p>The following exceptions will produce this effect.</p>
! 2134: <pre>STRUCT
1.1 cvs 2135: ...
1.5 cvs 2136: Graphics_object (ATTR Height = Integer; Width = Integer)
1.1 cvs 2137: = GRAPHICS with Height ?= 10, Width ?= 10;
2138: ...
2139: EXCEPT
2140: Height: NewHeight, Invisible;
1.18 cvs 2141: Width: NewWidth, Invisible;</pre>
2142: </blockquote>
2143: </div>
2144: </div>
1.1 cvs 2145:
1.18 cvs 2146: <div class="section">
1.30 ! cvs 2147: <h2><a name="sectb33">Some examples</a></h2>
1.1 cvs 2148:
1.30 ! cvs 2149: <p>In order to illustrate the principles of the document model and the syntax
! 2150: of the S language, this section presents two examples of structure schemas.
! 2151: One defines a class of documents, the other defines a class of objects.</p>
1.1 cvs 2152:
1.18 cvs 2153: <div class="subsection">
1.30 ! cvs 2154: <h3><a name="sectc331">A class of documents: articles</a></h3>
1.1 cvs 2155:
1.30 ! cvs 2156: <p>This example shows a possible structure for articles published in a
! 2157: journal. Text between braces is comments.</p>
1.18 cvs 2158: <pre>STRUCTURE Article; { This schema defines the Article class }
1.1 cvs 2159: DEFPRES ArticleP; { The default presentation schema is
2160: ArticleP }
2161: ATTR { Global attribute definitions }
2162: WordType = Definition, IndexWord, DocumentTitle;
2163: { A single global attribute is defined, with three values }
2164: STRUCT { Definition of the generic structure }
2165: Article = BEGIN { The Article class has an aggregate
2166: structure }
2167: Title = BEGIN { The title is an aggregate }
2168: French_title =
2169: Text WITH Language='Fran\347ais';
2170: English_title =
2171: Text WITH Language='English';
2172: END;
2173: Authors =
2174: LIST OF (Author
2175: (ATTR Author_type=principal,secondary)
2176: { The Author type has a local attribute }
2177: = BEGIN
2178: Author_name = Text;
2179: Info = Paragraphs ;
2180: { Paragraphs is defined later }
2181: Address = Text;
2182: END
2183: );
2184: Keywords = Text;
2185: { The journal's editor introduces the article
2186: with a short introduction, in French and
2187: in English }
2188: Introduction =
2189: BEGIN
2190: French_intr = Paragraphs WITH
2191: Language='Fran\347ais';
2192: English_intr = Paragraphs WITH
2193: Language='English';
2194: END;
2195: Body = Sections; { Sections are defined later }
2196: { Appendixes are only created on demand }
2197: ? Appendices =
2198: LIST OF (Appendix =
2199: BEGIN
2200: Appendix_Title = Text;
2201: Appendix_Contents = Paragraphs;
2202: END
2203: );
2204: END; { End of the Article aggregate }
2205:
2206: Sections = LIST [2..*] OF (
2207: Section = { At least 2 sections }
2208: BEGIN
2209: Section_title = Text;
2210: Section_contents =
2211: BEGIN
2212: Paragraphs;
2213: Sections; { Sections at a lower level }
2214: END;
2215: END
2216: );
2217:
2218: Paragraphs = LIST OF (Paragraph = CASE OF
2219: Enumeration =
2220: LIST [2..*] OF
2221: (Item = Paragraphs);
2222: Isolated_formula = Formula;
2223: LIST OF (UNIT);
2224: END
2225: );
2226:
2227: ASSOC { Associated elements definitions }
2228:
2229: Figure = BEGIN
1.5 cvs 2230: Figure_caption = Text;
1.1 cvs 2231: Illustration = NATURE;
2232: END;
2233:
2234: Biblio_citation = CASE OF
2235: Ref_Article =
2236: BEGIN
2237: Authors_Bib = Text;
2238: Article_Title = Text;
2239: Journal = Text;
2240: Page_Numbers = Text;
2241: Date = Text;
2242: END;
2243: Ref_Livre =
2244: BEGIN
2245: Authors_Bib; { Defined above }
2246: Book_Title = Text;
2247: Editor = Text;
2248: Date; { Defined above }
2249: END;
2250: END;
2251:
2252: Note = Paragraphs - (Ref_note);
2253:
2254: UNITS { Elements which can be used in objects }
2255:
2256: Ref_note = REFERENCE (Note);
2257: Ref_biblio = REFERENCE (Biblio_citation);
2258: Ref_figure = REFERENCE (Figure);
2259: Ref_formula = REFERENCE (Isolated_formula);
2260:
2261: EXPORT { Skeleton elements }
2262:
2263: Title,
1.5 cvs 2264: Figure with Figure_caption,
1.1 cvs 2265: Section With Section_title;
2266:
1.18 cvs 2267: END { End of the structure schema }</pre>
1.30 ! cvs 2268:
! 2269: <p>This schema is very complete since it defines both paragraphs and
1.1 cvs 2270: bibliographic citations. These element types could just as well be defined in
1.18 cvs 2271: other structure schemas, as is the case with the <tt>Formula</tt> class. All
1.1 cvs 2272: sorts of other elements can be inserted into an article, since a paragraph can
2273: contain any type of unit. Similarly, figures can be any class of document or
1.18 cvs 2274: object that the user chooses.</p>
1.30 ! cvs 2275:
! 2276: <p>Generally, an article doesn't contain appendices, but it is possible to add
1.1 cvs 2277: them on explicit request: this is the effect of the question mark before the
1.18 cvs 2278: word Appendices.</p>
1.30 ! cvs 2279:
! 2280: <p>The Figure, Biblio_citation and Note elements are associated elements.
! 2281: Thus, they are only used in <tt>REFERENCE</tt> statements.</p>
! 2282:
! 2283: <p>Various types of cross-references can be put in paragraphs. They can also
! 2284: be placed the objects which are part of the article, since the
! 2285: cross-references are defined as units (<tt>UNITS</tt>).</p>
! 2286:
! 2287: <p>There is a single restriction to prevent the creation of Ref_note elements
1.18 cvs 2288: within notes.</p>
1.30 ! cvs 2289:
! 2290: <p>It is worth noting that the S language permits the definition of recursive
1.1 cvs 2291: structures like sections: a section can contain other sections (which are thus
2292: at the next lower level of the document tree). Paragraphs are also recursive
2293: elements, since a paragraph can contain an enumeration in which each element
1.18 cvs 2294: (<tt>Item</tt>) is composed of paragraphs.</p>
2295: </div>
1.1 cvs 2296:
1.18 cvs 2297: <div class="subsection">
1.30 ! cvs 2298: <h3><a name="sectc332">A class of objects: mathematical formulas</a></h3>
1.1 cvs 2299:
1.30 ! cvs 2300: <p>The example below defines the <tt>Formula</tt> class which is used in
! 2301: Article documents. This class represents mathematical formulas with a rather
! 2302: simple structure, but sufficient to produce a correct rendition on the screen
! 2303: or printer. To support more elaborate operations (formal or numeric
1.1 cvs 2304: calculations), a finer structure should be defined. This class doesn't use any
1.18 cvs 2305: other class and doesn't define any associated elements or units.</p>
2306: <pre>STRUCTURE Formula;
1.1 cvs 2307: DEFPRES FormulaP;
2308:
2309: ATTR
2310: String_type = Function_name, Variable_name;
2311:
2312: STRUCT
2313: Formula = Expression;
2314: Expression = LIST OF (Construction);
2315: Construction = CASE OF
2316: TEXT; { Simple character string }
2317: Index = Expression;
2318: Exponent = Expression;
2319: Fraction =
2320: BEGIN
1.6 cvs 2321: Numerator = Expression;
1.1 cvs 2322: Denominator = Expression;
2323: END;
2324: Root =
2325: BEGIN
2326: ? Order = TEXT;
2327: Root_Contents = Expression;
2328: END;
2329: Integral =
2330: BEGIN
2331: Integration_Symbol = SYMBOL;
2332: Lower_Bound = Expression;
2333: Upper_Bound = Expression;
2334: END;
2335: Triple =
2336: BEGIN
2337: Princ_Expression = Expression;
2338: Lower_Expression = Expression;
2339: Upper_Expression = Expression;
2340: END;
2341: Column = LIST [2..*] OF
2342: (Element = Expression);
2343: Parentheses_Block =
2344: BEGIN
2345: Opening = SYMBOL;
2346: Contents = Expression;
2347: Closing = SYMBOL;
2348: END;
2349: END; { End of Choice Constructor }
1.18 cvs 2350: END { End of Structure Schema }</pre>
1.30 ! cvs 2351:
! 2352: <p>This schema defines a single global attribute which allows functions and
1.1 cvs 2353: variables to be distinguished. In the presentation schema, this attribute can
2354: be used to choose between roman (for functions) and italic characters (for
1.18 cvs 2355: variables).</p>
1.30 ! cvs 2356:
! 2357: <p>A formula's structure is that of a mathematical expression, which is itself
! 2358: a sequence of mathematical constructions. A mathematical construction can be
1.1 cvs 2359: either a simple character string, an index, an exponent, a fraction, a root,
2360: etc. Each of these mathematical constructions has a sensible structure which
2361: generally includes one or more expressions, thus making the formula class's
1.18 cvs 2362: structure definition recursive.</p>
1.30 ! cvs 2363:
! 2364: <p>In most cases, the roots which appear in the formulas are square roots and
1.1 cvs 2365: their order (2) is not specified. This is why the Order component is marked
2366: optional by a question mark. When explicitly requested, it is possible to add
1.18 cvs 2367: an order to a root, for example for cube roots (order = 3).</p>
1.30 ! cvs 2368:
! 2369: <p>An integral is formed by an integration symbol, chosen by the user (simple
1.1 cvs 2370: integral, double, curvilinear, etc.), and two bounds. A more fine-grained
2371: schema would add components for the integrand and the integration variable.
2372: Similarly, the Block_Parentheses construction leaves the choice of opening and
2373: closing symbols to the user. They can be brackets, braces, parentheses,
1.18 cvs 2374: etc.</p>
2375: </div>
2376: </div>
2377: <hr>
2378: </div>
1.1 cvs 2379:
1.18 cvs 2380: <div class="chapter">
2381: <h1><a name="sect4">The P Language</a></h1>
1.1 cvs 2382:
1.18 cvs 2383: <div class="section">
1.30 ! cvs 2384: <h2><a name="sectb41">Document presentation</a></h2>
1.1 cvs 2385:
1.30 ! cvs 2386: <p>Because of the model adopted for Thot, the presentation of documents is
1.1 cvs 2387: clearly separated from their structure and content. After having presented
2388: the logical structure of documents, we now detail the principles implemented
1.18 cvs 2389: for their presentation. The concept of <em>presentation</em> encompasses what
1.5 cvs 2390: is often called the page layout, the composition, or the document style. It
1.18 cvs 2391: is the set of operations which display the document on the screen or print it
2392: on paper. Like logical structure, document presentation is defined
2393: generically with the help of a language, called P.</p>
1.1 cvs 2394:
1.18 cvs 2395: <div class="subsection">
1.30 ! cvs 2396: <h3><a name="sectc411">Two levels of presentation</a></h3>
1.1 cvs 2397:
1.30 ! cvs 2398: <p>The link between structure and presentation is clear: the logical
! 2399: organization of a document is used to carry out its presentation, since the
! 2400: purpose of the presentation is to make evident the organization of the
! 2401: document. But the presentation is equally dependent on the device used to
! 2402: render the document. Certain presentation effects, notably changes of font or
! 2403: character set, cannot be performed on all printers or on all screens. This is
! 2404: why Thot uses a two-level approach, where the presentation is first described
! 2405: in abstract terms, without taking into account each particular device, and
! 2406: then the presentation is realized within the constraints of a given
! 2407: device.</p>
! 2408:
! 2409: <p>Thus, presentation is only described as a function of the structure of the
1.1 cvs 2410: documents and the image that would be produced on an idealized device. For
2411: this reason, presentation descriptions do not refer to any device
1.18 cvs 2412: characteristics: they describe <em>abstract presentations</em> which can be
2413: concretized on different devices.</p>
1.30 ! cvs 2414:
! 2415: <p>A presentation description also defines a <em>generic presentation</em>,
! 2416: since it describes the appearance of a class of documents or objects. This
! 2417: generic presentation must also be applied to document and object instances,
! 2418: each conforming to its generic logical structure, but with all the allowances
! 2419: that were called to mind above: missing elements, constructed elements with
! 2420: other logical structures, etc.</p>
! 2421:
! 2422: <p>In order to preserve the homogeneity between documents and objects,
1.1 cvs 2423: presentation is described with a single set of tools which support the layout
2424: of a large document as well as the composition of objects like a graphical
2425: figure or mathematical formula. This unity of presentation description tools
2426: contrasts with the traditional approach, which focuses more on documents than
2427: objects and thus is based on the usual typographic conventions, such as the
2428: placement of margins, indentations, vertical spaces, line lengths,
1.18 cvs 2429: justification, font changes, etc.</p>
2430: </div>
1.1 cvs 2431:
1.18 cvs 2432: <div class="subsection">
1.30 ! cvs 2433: <h3><a name="sectc412">Boxes</a></h3>
1.1 cvs 2434:
1.30 ! cvs 2435: <p>To assure the homogeneity of tools, all presentation in Thot, for documents
! 2436: as well as for the objects which they contain, is based on the notion of the
1.18 cvs 2437: <em>box</em>, such as was implemented in T<sub><big>E</big></sub>X.</p>
1.30 ! cvs 2438:
! 2439: <p>Corresponding to each element of the document is a box, which is the
1.1 cvs 2440: rectangle enclosing the element on the display device (screen or sheet of
1.18 cvs 2441: paper); the outline of this rectangle is not visible, except when a <a
2442: href="#sectc4230a"><tt>ShowBox</tt> rule</a> applies to the element. The sides
2443: of the box are parallel to the sides of the screen or the sheet of paper. By
2444: way of example, a box is associated with a character string, a line of text, a
2445: page, a paragraph, a title, a mathematical formula, or a table cell.</p>
1.30 ! cvs 2446:
! 2447: <p>Whatever element it corresponds to, each box possesses four sides and four
1.18 cvs 2448: axes, which we designate as follows (<a href="#boxes">see figure</a>):</p>
2449: <dl>
1.30 ! cvs 2450: <dt><tt>Top</tt></dt>
! 2451: <dd>the upper side,</dd>
! 2452: <dt><tt>Bottom</tt></dt>
! 2453: <dd>the lower side,</dd>
! 2454: <dt><tt>Left</tt></dt>
! 2455: <dd>the left side,</dd>
! 2456: <dt><tt>Right</tt></dt>
! 2457: <dd>the right side,</dd>
! 2458: <dt><tt>VMiddle</tt></dt>
! 2459: <dd>the vertical axis passing through the center of the box,</dd>
! 2460: <dt><tt>HMiddle</tt></dt>
! 2461: <dd>the horizontal axis passing through the center of the box,</dd>
! 2462: <dt><tt>VRef</tt></dt>
! 2463: <dd>the vertical reference axis,</dd>
! 2464: <dt><tt>HRef</tt></dt>
! 2465: <dd>the horizontal reference axis.</dd>
1.18 cvs 2466: </dl>
2467:
2468: <div class="figure">
2469: <hr>
2470: <pre> Left VRef VMiddle Right
1.1 cvs 2471: : :
2472: Top -----------------------------
2473: | : : |
2474: | : : |
2475: | : : |
2476: | : : |
2477: | : : |
2478: HMiddle ..|...........................|..
2479: | : : |
2480: | : : |
2481: HRef ..|...........................|..
2482: | : : |
2483: | : : |
2484: Bottom -----------------------------
1.18 cvs 2485: : :</pre>
1.30 ! cvs 2486:
! 2487: <p align="center"><em><a name="boxes">The sides and axes of
! 2488: boxes</a><em></em></em></p>
1.18 cvs 2489: <hr>
1.30 ! cvs 2490: </div>
1.19 cvs 2491:
1.30 ! cvs 2492: <p>The principal role of boxes is to set the extent and position of the images
! 2493: of the different elements of a document with respect to each other on the
1.1 cvs 2494: reproduction device. This is done by defining relations between the boxes of
2495: different elements which give relative extents and positions to these
1.18 cvs 2496: boxes.</p>
1.30 ! cvs 2497:
! 2498: <p>There are three types of boxes:</p>
1.18 cvs 2499: <ul>
1.30 ! cvs 2500: <li>boxes corresponding to structural elements of the document,</li>
! 2501: <li>presentation boxes,</li>
! 2502: <li>page layout boxes.</li>
1.18 cvs 2503: </ul>
1.30 ! cvs 2504:
! 2505: <p><strong>Boxes corresponding to structural elements of the document</strong>
1.1 cvs 2506: are those which linked to each of the elements (base or structured) of the
2507: logical structure of the document. Such a box contains all the contents of
1.18 cvs 2508: the element to which it corresponds (there is an exception: see <a
2509: href="#sectc4220">rules <tt>VertOverflow</tt> and <tt>HorizOverflow</tt></a>).
2510: These boxes form a tree-like structure, identical to that of the structural
2511: elements to which they correspond. This tree expresses the inclusion
2512: relationships between the boxes: a box includes all the boxes of its subtree.
2513: On the other hand, there are no predefined rules for the relative positions of
2514: the included boxes. If they are at the same level, they can overlap, be
2515: contiguous, or be disjoint. The rules expressed in the generic presentation
2516: specify their relative positions.</p>
1.30 ! cvs 2517:
! 2518: <p><strong>Presentation boxes</strong> represent elements which are not found
! 2519: in the logical structure of the document but which are added to meet the needs
! 2520: of presentation. These boxes are linked to the elements of the logical
! 2521: structure that are best suited to bringing them out. For example, they are
! 2522: used to add the character string ``Summary:'' before the summary in the
! 2523: presentation of a report or to represent the fraction bar in a formula, or
! 2524: also to make the title of a field in a form appear. These elements have no
! 2525: role in the logical structure of the document: the presence of a Summary
! 2526: element in the document does not require the creation of another structural
! 2527: object to hold the word ``Summary''. Similarly, if a Fraction element contains
! 2528: both a Numerator element and a Denominator element, the fraction bar has no
! 2529: purpose structurally. On the other hand, these elements of the presentation
! 2530: are important for the reader of the reproduced document or for the user of an
1.1 cvs 2531: editor. This is why they must appear in the document's image. It is the
2532: generic presentation which specifies the presentation boxes to add by
2533: indicating their content (a base element for which the value is specified) and
2534: the position that they must take in the tree of boxes. During editing, these
1.18 cvs 2535: boxes cannot be modified by the user.</p>
1.30 ! cvs 2536:
! 2537: <p><strong>Page layout boxes</strong> are boxes created implicitly by the page
1.1 cvs 2538: layout rules. These rules indicate how the contents of a structured element
2539: must be broken into lines and pages. In contrast to presentation boxes, these
2540: line and page boxes do not depend on the logical structure of the document,
1.18 cvs 2541: but rather on the physical constraints of the output devices: character size,
2542: height and width of the window on the screen or of the sheet of paper.</p>
2543: </div>
1.1 cvs 2544:
1.18 cvs 2545: <div class="subsection">
1.30 ! cvs 2546: <h3><a name="sectc413">Views and visibility</a></h3>
1.1 cvs 2547:
1.30 ! cvs 2548: <p>One of the operations that one might wish to perform on a document is to
! 2549: view it is different ways. For this reason, it is possible to define several
1.18 cvs 2550: <em>views</em> for the same document, or better yet, for all documents of the
1.1 cvs 2551: same class. A view is not a different presentation of the document, but
2552: rather a filter which only allows the display of certain parts of the
2553: document. For example, it might be desirable to see only the titles of
2554: chapters and sections in order to be able to move rapidly through the
2555: document. Such a view could be called a ``table of contents''. It might also
2556: be desirable to see only the mathematical formulas of a document in order to
2557: avoid being distracted by the non-mathematical aspects of the document. A
1.18 cvs 2558: ``mathematics'' view could provide this service.</p>
1.30 ! cvs 2559:
! 2560: <p>Views, like presentation, are based on the generic logical structure. Each
1.1 cvs 2561: document class, and each generic presentation, can be provided with views
2562: which are particularly useful for that class or presentation. For each view,
1.18 cvs 2563: the <em>visibility</em> of elements is defined, indicated whether or not the
1.1 cvs 2564: elements must be presented to the user. The visibility is calculated as a
2565: function of the type of the elements or their hierarchical position in the
2566: structure of the document. Thus, for a table of contents, all the ``Chapter
2567: Title'' and ``Section Title'' elements are made visible. However, the
2568: hierarchical level could be used to make the section titles invisible below a
2569: certain threshold level. By varying this threshold, the granularity of the
2570: view can be varied. In the ``mathematics'' view, only Formula elements would
1.18 cvs 2571: be made visible, no matter what their hierarchical level.</p>
1.30 ! cvs 2572:
! 2573: <p>Because views are especially useful for producing a synthetic image of the
1.1 cvs 2574: document, it is necessary to adapt the presentation of the elements to the
2575: view in which they appear. For example, it is inappropriate to have a page
2576: break before every chapter title in the table of contents. Thus, generic
2577: presentations take into account the possible views and permit each element
1.18 cvs 2578: type's presentation to vary according the view in which its image appears.</p>
1.30 ! cvs 2579:
! 2580: <p><a name="views">Views</a> are also used, when editing documents, to display
1.1 cvs 2581: the associated elements. So, in addition to the primary view of the document,
2582: there can be a ``notes'' view and a ``figures'' view which contain,
2583: respectively, the associated elements of the Note and Figure types. In this
2584: way, it is possible to see simultaneously the text which refers to these
2585: elements and the elements themselves, even if they will be separated when
1.18 cvs 2586: printed.</p>
2587: </div>
1.1 cvs 2588:
1.18 cvs 2589: <div class="subsection">
1.30 ! cvs 2590: <h3><a name="sectc414">Pages</a></h3>
1.1 cvs 2591:
1.30 ! cvs 2592: <p>Presentation schemas can be defined which display the document as a long
1.1 cvs 2593: scroll, without page breaks. This type of schema is particularly well-suited
2594: to the initial phase of work on a document, where jumps from page to page
2595: would hinder composing and reading the document on a screen. In this case,
2596: the associated elements (such as notes), which are normally displayed in the
2597: page footer, are presented in a separate window. But, once the document is
2598: written, it may be desirable to display the document on the screen in the same
2599: manner in which it will be printed. So, the presentation schema must define
1.18 cvs 2600: pages.</p>
1.30 ! cvs 2601:
! 2602: <p>The P language permits the specification of the dimensions of pages as well
! 2603: as their composition. It is possible to generate running titles, page
! 2604: numbers, zones at the bottom of the page for notes, etc. The editor follows
! 2605: this model and inserts page break marks in the document which are used during
! 2606: printing, insuring that the pages on paper are the same as on the screen.</p>
! 2607:
! 2608: <p>Once a document has been edited with a presentation schema defining pages,
! 2609: it contains page marks. But it is always possible to edit the document using
! 2610: a schema without pages. In this case, the page marks are simply ignored by
! 2611: the editor. They are considered again as soon as a schema with pages is used.
1.18 cvs 2612: Thus, the user is free to choose between schemas with and without pages.</p>
1.30 ! cvs 2613:
! 2614: <p>Thot treats the page break, rather than the page itself, as a box. This
! 2615: page break box contains all the elements of one page's footer, a rule marking
! 2616: the edge of this page, and all the elements of the next page's header. The
1.1 cvs 2617: elements of the header and footer can be running titles, page number,
2618: associated elements (notes, for example), etc. All these elements, as well as
2619: their content and graphical appearance, are defined by the generic
1.18 cvs 2620: presentation.</p>
2621: </div>
1.1 cvs 2622:
1.18 cvs 2623: <div class="subsection">
1.30 ! cvs 2624: <h3><a name="sectc415">Numbering</a></h3>
1.1 cvs 2625:
1.30 ! cvs 2626: <p>Many elements are numbered in documents: pages, chapters, sections,
! 2627: formulas, theorems, notes, figures, bibliographic references, exercises,
! 2628: examples, lemmas, etc. Because Thot has a notion of logical structure, all of
! 2629: these numbers (with the exception of pages) are redundant with information
! 2630: implicit in the logical structure of the document. Such numbers are simply a
! 2631: way to make the structure of the document more visible. So, they are part of
! 2632: the document's presentation and are calculated by the editor from the logical
1.1 cvs 2633: structure. The structure does not contain numbers as such; it only defines
2634: relative structural positions between elements, which serve as ordering
1.18 cvs 2635: relations on these elements.</p>
1.30 ! cvs 2636:
! 2637: <p>If the structure schema defines the body of a document as a sequence of at
1.18 cvs 2638: least two chapters:</p>
2639: <pre>Body = LIST [2..*] OF Chapter;</pre>
1.30 ! cvs 2640:
! 2641: <p>the sequence defined by the list constructor is ordered and each chapter
! 2642: can be assigned a number based on its rank in the Body list. Therefore, all
1.18 cvs 2643: elements contained in lists a the structure of a document can be numbered, but
2644: they are not the only ones. The tree structure induced by the aggregate,
2645: list, and choice constructors (excluding references) defines a total order on
2646: the elements of the document's primary structure. So, it is possible to
2647: define a numbering which uses this order, filtering elements according to
2648: their type so that only certain element types are taken into account in the
2649: numbering. In this way, it possible to number all the theorems and lemmas of
2650: a chapter in the same sequence of numbers, even when they are not part of the
2651: same list constructor and appear at different levels of the document's tree.
2652: By changing the filter, they can be numbered separately: one sequence of
2653: numbers for theorems, another for the lemmas.</p>
1.30 ! cvs 2654:
! 2655: <p>Associated elements pose a special problem, since they are not part of the
1.1 cvs 2656: document's primary structure, but are attached only by references, which
2657: violate the total order of the document. Then, these associated elements are
2658: frequently numbered, precisely because the number is an effective way to
2659: visualize the reference. In order to resolve this problem, Thot implicitly
2660: defines a list constructor for each type of associated element, gathering
2661: together (and ordering) these elements. Thus, the associated elements can be
1.18 cvs 2662: numbered by type.</p>
1.30 ! cvs 2663:
! 2664: <p>Since they are calculated from the document's logical structure and only
! 2665: for the needs of the presentation, numbers are presentation elements,
! 2666: described by presentation boxes, just like the fraction bar or the word
! 2667: ``Summary''. Nevertheless, numbers differ from these other boxes because their
! 2668: content varies from instance to instance, even though they are of the same
! 2669: type, whereas all fraction bars are horizontal lines and the same word
! 2670: ``Summary'' appears at the head of every document's summary.</p>
1.18 cvs 2671: </div>
1.1 cvs 2672:
1.18 cvs 2673: <div class="subsection">
1.30 ! cvs 2674: <h3><a name="sectc416">Presentation parameters</a></h3>
1.1 cvs 2675:
1.30 ! cvs 2676: <p>The principal parameters which determine document presentation are the
1.18 cvs 2677: <em>positions</em> and <em>dimensions</em> of boxes, the <em>font</em>, the
2678: <em>style</em>, the <em>size</em>, the <em>underlining</em> and the
2679: <em>color</em> of their content. From these parameters, and some others of
1.1 cvs 2680: less importance, it is possible to represent the usual typographic parameters
2681: for the textual parts of the document. These same parameters can be used to
2682: describe the geometry of the non-textual elements, even though they are
1.18 cvs 2683: two-dimensional elements unlike the text, which is linear.</p>
1.30 ! cvs 2684:
! 2685: <p>As we have already seen, the positions of the boxes always respect the
! 2686: rule of enclosure: a box in the tree encloses all the boxes of the next lower
! 2687: level which are attached to it. The positional parameters permit the
! 2688: specification of the position of each box in relation to the enclosing box or
! 2689: to its sibling boxes (boxes directly attached to the same enclosing box in the
! 2690: tree of boxes).</p>
! 2691:
! 2692: <p>The presentation parameters also provide control over the dimensions of the
1.1 cvs 2693: boxes. The dimensions of a box can depend either on its content or on its
2694: context (its sibling boxes and the enclosing box). Each dimension (height or
1.18 cvs 2695: width) can be defined independently of the other.</p>
1.30 ! cvs 2696:
! 2697: <p>Because of the position and dimension parameters, it is possible to do the
1.1 cvs 2698: same things that are normally done in typography by changing margins, line
2699: lengths, and vertical or horizontal skips. This approach can also align or
1.18 cvs 2700: center elements and groups of elements.</p>
1.30 ! cvs 2701:
! 2702: <p>In contrast to the position and dimension parameters, the font, style,
! 2703: size, underlining, and color do not concern the box itself (the rectangle
! 2704: delimiting the element), but its content. These parameters indicate the
! 2705: typographic attributes which must be applied to the text contained in the box,
! 2706: and by extension, to all base elements.</p>
! 2707:
! 2708: <p>For text, the font parameter is used to change the family of characters
1.1 cvs 2709: (Times, Helvetica, Courier, etc.); the style is used to obtain italic or
2710: roman, bold or light characters; the size determines the point size of the
2711: characters; underlining defines the type and thickness of the lines drawn
1.18 cvs 2712: above, below, or through the characters.</p>
1.30 ! cvs 2713:
! 2714: <p>For graphics, the line style parameter can be either solid, dotted, or
! 2715: dashed; the line thickness parameter controls the width of the lines; the fill
! 2716: pattern parameter determines how closed geometric figures must be filled.</p>
! 2717:
! 2718: <p>While some of the parameters which determine the appearance of a box's
1.1 cvs 2719: contents make sense only for one content type (text or graphic), other
2720: parameters apply to all content types: these are the color parameters. These
1.18 cvs 2721: indicate the color of lines and the background color.</p>
2722: </div>
2723: </div>
1.1 cvs 2724:
1.18 cvs 2725: <div class="section">
1.30 ! cvs 2726: <h2><a name="sectb42">Presentation description language</a></h2>
! 2727:
! 2728: <p>A generic presentation defines the values of presentation parameters (or
! 2729: the way to calculate those values) for a generic structure, or more precisely,
! 2730: for all the element types and all the global and local attributes defined in
! 2731: that generic structure. This definition of the presentation parameters is
! 2732: made with the P language. A program written in this language, that is a
! 2733: generic presentation expressed in P, is call a <em>presentation schema</em>.
! 2734: This section describes the syntax and semantics of the language, using the
! 2735: same <a href="#sectc321">meta-language</a> as was used for the definition of
! 2736: the S language.</p>
1.1 cvs 2737:
1.30 ! cvs 2738: <p>Recall that it is possible to write many different presentation schemas for
1.1 cvs 2739: the same class of documents or objects. This allows users to choose for a
2740: document the graphical appearance which best suits their type of work or
1.18 cvs 2741: their personal taste.</p>
1.1 cvs 2742:
1.18 cvs 2743: <div class="subsection">
1.30 ! cvs 2744: <h3><a name="sectc421">The organization of a presentation schema</a></h3>
1.1 cvs 2745:
1.30 ! cvs 2746: <p>A presentation schema begins with the word <tt>PRESENTATION</tt> and ends
! 2747: with the word <tt>END</tt>. The word <tt>PRESENTATION</tt> is followed by the
! 2748: name of the generic structure to which the presentation will be applied. This
! 2749: name must be the same as that which follows the keyword <tt>STRUCTURE</tt> in
! 2750: the structure schema associated with the presentation schema.</p>
! 2751:
! 2752: <p>After this declaration of the name of the structure, the following sections
1.18 cvs 2753: appear (in order):</p>
2754: <ul>
1.30 ! cvs 2755: <li>Declarations of
! 2756: <ul>
! 2757: <li>all views,</li>
! 2758: <li>printed views,</li>
! 2759: <li>counters,</li>
! 2760: <li>presentation constants,</li>
! 2761: <li>variables,</li>
! 2762: </ul>
! 2763: </li>
! 2764: <li>default presentation rules,</li>
! 2765: <li>presentation box and page layout box definitions,</li>
! 2766: <li>presentation rules for structured elements,</li>
! 2767: <li>presentation rules for attributes,</li>
! 2768: <li>rules for transmitting values to attributes of included documents.</li>
1.18 cvs 2769: </ul>
1.30 ! cvs 2770:
! 2771: <p>Each of these sections is introduced by a keyword which is followed by a
1.18 cvs 2772: sequence of declarations. Every section is optional.</p>
2773: <pre> SchemaPres ='PRESENTATION' ElemID ';'
1.1 cvs 2774: [ 'VIEWS' ViewSeq ]
2775: [ 'PRINT' PrintViewSeq ]
2776: [ 'COUNTERS' CounterSeq ]
2777: [ 'CONST' ConstSeq ]
2778: [ 'VAR' VarSeq ]
2779: [ 'DEFAULT' ViewRuleSeq ]
2780: [ 'BOXES' BoxSeq ]
2781: [ 'RULES' PresentSeq ]
2782: [ 'ATTRIBUTES' PresAttrSeq ]
2783: [ 'TRANSMIT' TransmitSeq ]
2784: 'END' .
1.18 cvs 2785: ElemID = NAME .</pre>
2786: </div>
1.1 cvs 2787:
1.18 cvs 2788: <div class="subsection">
1.30 ! cvs 2789: <h3><a name="sectc422">Views</a></h3>
1.1 cvs 2790:
1.30 ! cvs 2791: <p>Each of the possible views must be declared in the presentation schema. As
1.18 cvs 2792: has <a href="#views">already been described</a>, the presentation rules for an
1.1 cvs 2793: element type can vary according to the view in which the element appears. The
2794: name of the view is used to designate the view to which the presentation rules
1.18 cvs 2795: apply (see the <a href="#inkeyword"><tt>IN</tt> instruction</a>). The
1.1 cvs 2796: definition of the view's contents are dispersed throughout the presentation
2797: rules attached to the different element types and attributes. The
1.18 cvs 2798: <tt>VIEWS</tt> section is simply a sequence of view names separated by commas
2799: and terminated by a semi-colon.</p>
1.30 ! cvs 2800:
! 2801: <p>One of the view names (and only one) can be followed by the keyword
1.18 cvs 2802: <tt>EXPORT</tt>. This keyword identifies the view which presents the members
2803: of the document class in <a href="#sectc3213">skeleton form</a>. The
2804: graphical appearance and the content of this view is defined just as with
2805: other views, but it is useless to specify presentation rules concerning this
2806: view for the elements which are not loaded in the skeleton form.</p>
1.30 ! cvs 2807:
! 2808: <p>It is not necessary to declare any views; in this case there is a single
1.1 cvs 2809: unnamed view. If many views are declared, the first view listed is considered
2810: the principal view. The principal view is the one to which all rules that are
1.18 cvs 2811: not preceded by an indication of a view will apply (see the <a
2812: href="#inkeyword">instruction <tt>IN</tt></a>).</p>
1.30 ! cvs 2813:
! 2814: <p>The principal view is the the one which the editor presents on the screen
! 2815: when the user asks to create or edit a document. Thus, it makes sense to put
! 2816: the most frequently used view at the head of the list. But if the structure
1.18 cvs 2817: schema contains <a href="#sectc3213">skeleton elements</a> and is loaded in
2818: its skeleton form, the view whose name is followed by the keyword
2819: <tt>EXPORT</tt> will be opened and no other views can be opened.</p>
2820: <pre> 'VIEWS' ViewSeq
1.1 cvs 2821: ViewSeq = ViewDeclaration
1.30 ! cvs 2822: < ',' ViewDeclaration > ';' .
1.1 cvs 2823: ViewDeclaration = ViewID [ 'EXPORT' ] .
1.18 cvs 2824: ViewID = NAME .</pre>
1.30 ! cvs 2825:
1.18 cvs 2826: <blockquote class="example">
1.30 ! cvs 2827: <p><strong>Example:</strong></p>
! 2828:
! 2829: <p>When editing a report, it might be useful have views of the table of
! 2830: contents and of the mathematical formulas, in addition to the principal view
! 2831: which shows the document in its entirety. To achieve this, a presentation
! 2832: schema for the Report class would have the following <tt>VIEWS</tt>
! 2833: section:</p>
! 2834: <pre>VIEWS
1.18 cvs 2835: Full_text, Table_of_contents, Formulas;</pre>
1.30 ! cvs 2836:
! 2837: <p>The contents of these views are specified in the presentation rules of
! 2838: the schema.</p>
1.18 cvs 2839: </blockquote>
2840: </div>
1.1 cvs 2841:
1.18 cvs 2842: <div class="subsection">
1.30 ! cvs 2843: <h3><a name="sectc423">Print Views</a></h3>
1.1 cvs 2844:
1.30 ! cvs 2845: <p>When editing a document, each view is presented in a different window. In
1.18 cvs 2846: addition to the views specified by the <tt>VIEWS</tt> instruction, the user
1.1 cvs 2847: can display the associated elements with one window for each type of
1.18 cvs 2848: associated element.</p>
1.30 ! cvs 2849:
! 2850: <p>When printing a document, it is possible to print any number of views,
! 2851: chosen from among all the views which the editor can display (views in the
! 2852: strict sense or associated elements). Print views, as well as the order in
! 2853: which they must be printed, are indicated by the <tt>PRINT</tt> instruction.
! 2854: It appears after the <tt>VIEWS</tt> instruction and is formed of the keyword
1.18 cvs 2855: <tt>PRINT</tt> followed by the ordered list of print view names. The print
1.1 cvs 2856: view names are separated by commas and followed by a semi-colon. A print view
1.18 cvs 2857: name is either a view name declared in the <tt>VIEWS</tt> instruction or the
1.1 cvs 2858: name of an associated element type (with an ``s'' added to the end). The
1.18 cvs 2859: associated element must have been declared in the <tt>ASSOC</tt> section of
2860: the structure schema.</p>
2861: <pre> 'PRINT' PrintViewSeq
1.30 ! cvs 2862: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.18 cvs 2863: PrintView = ViewID / ElemID .</pre>
1.30 ! cvs 2864:
! 2865: <p>If the <tt>PRINT</tt> instruction is absent, the printing program will
! 2866: print only the principal view (the first view specified by the <tt>VIEWS</tt>
1.18 cvs 2867: instruction or the single, unnamed view when there is no <tt>VIEWS</tt>
2868: instruction).</p>
1.30 ! cvs 2869:
1.18 cvs 2870: <blockquote class="example">
1.30 ! cvs 2871: <p><strong>Example:</strong></p>
! 2872:
! 2873: <p>Consider a Report presentation using the view declarations from the
! 2874: preceding example. Suppose we want to print the full text and table of
! 2875: contents views, but not the Formulas view, which is only useful when
! 2876: editing. In addition, suppose that we also want to print the bibliographic
! 2877: citations, which are associated elements (of type <tt>Citation</tt>). A
! 2878: sensible printing order would be to print the full text then the
! 2879: bibliography and finally the table of contents. To obtain this result when
! 2880: printing, the presentation schema would say:</p>
! 2881: <pre>PRINT
1.18 cvs 2882: Full_text, Citations, Table_of_contents;</pre>
2883: </blockquote>
2884: </div>
2885:
2886: <div class="subsection">
1.30 ! cvs 2887: <h3><a name="sectc424">Counters</a></h3>
1.18 cvs 2888:
1.30 ! cvs 2889: <p>A presentation has a <em>counter</em> for each type of number in the
1.1 cvs 2890: presentation. All counters, and therefore all types of numbers, used in the
1.18 cvs 2891: schema must be declared after the <tt>COUNTERS</tt> keyword.</p>
1.30 ! cvs 2892:
! 2893: <p>Each counter declaration is composed of a name identifying the counter
1.1 cvs 2894: followed by a colon and the counting function to be applied to the counter.
1.18 cvs 2895: The counter declaration ends with a semi-colon.</p>
1.30 ! cvs 2896:
! 2897: <p>The counting function indicates how the counter values will be calculated.
1.16 cvs 2898: Three types of counting functions are available. The first type is used to
2899: count the elements of a list or aggregate: it assigns to the counter the rank
1.18 cvs 2900: of the element in the list or aggregate. More precisely, the function</p>
2901: <pre>RANK OF ElemID [ LevelAsc ] [ INIT AttrID ]
2902: [ 'REINIT' AttrID ]</pre>
1.30 ! cvs 2903:
! 2904: <p>indicates that when an element creates, by a creation rule (see the <a
1.18 cvs 2905: href="#sectc4232"><tt>Create</tt> instructions</a>), a presentation box
1.5 cvs 2906: containing the counter value, this value is the rank of the creating element,
1.18 cvs 2907: if it is of type <tt>ElemID</tt>, otherwise the rank of the first element of
2908: type <tt>ElemID</tt> which encloses the creating element in the logical
2909: structure of the document.</p>
1.30 ! cvs 2910:
! 2911: <p>The type name can be preceded by a star in the special case where the
1.18 cvs 2912: structure schema defines an element of whose <tt>ElemID</tt> is the same as
2913: that of an <a href="#sectd3284">inclusion</a> without expansion or with
2914: partial expansion. To resolve this ambiguity, the <tt>ElemID</tt> alone
2915: refers to the type defined in the structure schema while the <tt>ElemID</tt>
2916: preceded by a star refers to the included type.</p>
1.30 ! cvs 2917:
! 2918: <p>The type name <tt>ElemID</tt> can be followed by an integer. That number
1.1 cvs 2919: represents the relative level, among the ancestors of the creating element, of
1.18 cvs 2920: the element whose rank is asked. If that relative level <i>n</i> is unsigned,
2921: the <i>n</i><sup>th</sup> element of type <tt>ElemID</tt> encountered when
1.1 cvs 2922: travelling the logical structure from the root to the creating element is
1.16 cvs 2923: taken into account. If the relative level is negative, the logical structure
2924: is travelled in the other direction, from the creating element to the
1.18 cvs 2925: root.</p>
1.30 ! cvs 2926:
! 2927: <p>The function can end with the keyword <tt>INIT</tt> followed by the name of
! 2928: a numeric attribute (and only a numeric attribute). Then, the rank of the
! 2929: first element of the list or aggregate is considered to be the value of this
1.1 cvs 2930: attribute, rather than the default value of 1, and the rank of the other
2931: elements is shifted accordingly. The attribute which determines the initial
1.18 cvs 2932: value is searched on the element itself and on its ancestors.</p>
1.30 ! cvs 2933:
! 2934: <p>The function can end with the keyword <tt>REINIT</tt> followed by the name
! 2935: of a numeric attribute (and only a numeric attribute). Then, if an element to
! 2936: be counted has this attribute, the counter value for this element is the
1.1 cvs 2937: attribute value and the following elements are numbered starting from this
1.18 cvs 2938: value.</p>
1.30 ! cvs 2939:
! 2940: <p>When the <tt>RANK</tt> function is written</p>
1.18 cvs 2941: <pre>RANK OF Page [ ViewID ] [ INIT AttrID ]</pre>
1.30 ! cvs 2942:
! 2943: <p>(<tt>Page</tt>is a keyword of the P language), the counter takes as its
! 2944: value the number of the page on which the element which creates the
! 2945: presentation box containing the number appears. This is done as if the pages
! 2946: of the document form a list for each view. The counter only takes into
! 2947: account the pages of the relevant view, that is the view displaying the
! 2948: presentation box whose contents take the value of the number. However, if the
! 2949: keyword <tt>Page</tt> is followed by the name of a view (between parentheses),
! 2950: it is the pages of that view that are taken into account. As in the preceding
! 2951: form, the <tt>RANK</tt> function applied to pages can end with the
! 2952: <tt>INIT</tt> keyword followed by the name of a numeric attribute which sets
! 2953: the value of the first page's number. This attribute must be a local
! 2954: attribute of the document itself, and not of one of its components.</p>
! 2955:
! 2956: <p>The second counting function is used to count the occurrences of a certain
1.18 cvs 2957: element type in a specified context. The instruction</p>
2958: <pre>SET n ON Type1 ADD m ON Type2 [ INIT AttrID ]</pre>
1.30 ! cvs 2959:
! 2960: <p>says that when the document is traversed from beginning to end (in the
! 2961: order induced by the logical structure), the counter is assigned the value
1.18 cvs 2962: <tt>n</tt> each time an element of type <tt>Type1</tt> is encountered, no
2963: matter what the current value of the counter, and the value <tt>m</tt> is
2964: added to the current value of the counter each time an element of type
2965: <tt>Type2</tt> is encountered.</p>
1.30 ! cvs 2966:
! 2967: <p>As with the <tt>RANK</tt> function, the type names can be preceded by a
! 2968: star to resolve the ambiguity of included elements.</p>
! 2969:
! 2970: <p>If the function ends with the keyword <tt>INIT</tt> followed by the name of
! 2971: an attribute and if the document possesses this attribute, the value of this
1.18 cvs 2972: attribute is used in place of <tt>n</tt>. The attribute must be numeric. It
2973: is searched on the element itself and on its ancestors.</p>
1.30 ! cvs 2974:
! 2975: <p>This function can also be used with the <tt>Page</tt> keyword in the place
! 2976: of <tt>Type1</tt> or <tt>Type2</tt>. In the first case, the counter is
1.18 cvs 2977: reinitialized on each page with the value <tt>n</tt>, while in the second
2978: case, it is incremented by <tt>m</tt> on each page. As with the preceding
2979: counting function, the word <tt>Page</tt> can be followed by a name between
1.1 cvs 2980: parentheses. In this case, the name specifies a view whose pages are taken
1.18 cvs 2981: into account.</p>
1.30 ! cvs 2982:
! 2983: <p>The definition of a counter can contain several <tt>SET</tt> functions and
1.18 cvs 2984: several <tt>ADD</tt> functions, each with a different value. The total number
2985: of counting functions must not be greater than 6.</p>
1.30 ! cvs 2986:
! 2987: <p>The third counting function is used to count the elements of a certain type
1.16 cvs 2988: encountered when travelling from the creating element to the root of the
2989: logical structure. The creating element is included if it is of that type.
1.18 cvs 2990: That function is written</p>
2991: <pre>RLEVEL OF Type</pre>
1.30 ! cvs 2992:
! 2993: <p>where <tt>Type</tt> represents the type of the elements to be counted.</p>
! 2994:
! 2995: <p>The formal definition of counter declarations is:</p>
1.18 cvs 2996: <pre> 'COUNTERS' CounterSeq
1.30 ! cvs 2997: CounterSeq = Counter < Counter > .
1.1 cvs 2998: Counter = CounterID ':' CounterFunc ';' .
2999: CounterID = NAME .
3000: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
1.16 cvs 3001: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.30 ! cvs 3002: SetFunction < SetFunction >
! 3003: AddFunction < AddFunction >
1.16 cvs 3004: [ 'INIT' AttrID ] /
3005: 'RLEVEL' 'OF' ElemID .
1.1 cvs 3006: SLevelAsc = [ '-' ] LevelAsc .
3007: LevelAsc = NUMBER .
3008: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
3009: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
3010: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 3011: [ '*' ] ElemID .
1.18 cvs 3012: CounterValue = NUMBER .</pre>
1.30 ! cvs 3013:
1.18 cvs 3014: <blockquote class="example">
1.30 ! cvs 3015: <p><strong>Example:</strong></p>
! 3016:
! 3017: <p>If the body of a chapter is defined as a sequence of sections in the
! 3018: structure schema:</p>
! 3019: <pre>Chapter_body = LIST OF (Section =
1.1 cvs 3020: BEGIN
3021: Section_Title = Text;
3022: Section_Body = Paragraphs;
3023: END
1.18 cvs 3024: );</pre>
1.30 ! cvs 3025:
! 3026: <p>the section counter is declared:</p>
! 3027: <pre>SectionCtr : RANK OF Section;</pre>
! 3028:
! 3029: <p>and the display of the section number before the section title is
! 3030: obtained by a <a href="#sectc4232"><tt>CreateBefore</tt> rule</a> attached
! 3031: the <tt>Section_Title</tt> type, which creates a presentation box whose
! 3032: content is the value of the <tt>SectionCtr</tt> counter (see the <a
! 3033: href="#sectc4231"><tt>Content</tt> instruction</a>).</p>
! 3034:
! 3035: <p>In order to number the formulas separately within each chapter, the
! 3036: formula counter is declared:</p>
! 3037: <pre>FormulaCtr : SET 0 ON Chapter ADD 1 ON Formula;</pre>
! 3038:
! 3039: <p>and the display of the formula number in the right margin, alongside each
! 3040: formula, is obtained by a <tt>CreateAfter</tt> instruction attached to the
! 3041: <tt>Formula</tt> type, which creates a presentation box whose content is the
! 3042: value of the <tt>FormulaCtr</tt> counter.</p>
! 3043:
! 3044: <p>To number the page chapter by chapter, with the first page of each
! 3045: chapter having the number 1, the counter definition would be</p>
! 3046: <pre>ChapterPageCtr : SET 0 ON Chapter ADD 1 ON Page;</pre>
! 3047:
! 3048: <p>If there is also a chapter counter</p>
! 3049: <pre>ChapterCtr : RANK OF Chapter;</pre>
! 3050:
! 3051: <p>the <a href="#sectc4231">content</a> of a presentation box created at the
! 3052: top of each page could be defined as:</p>
! 3053: <pre>Content : (VALUE(ChapterCtr, URoman) TEXT '-'
1.18 cvs 3054: VALUE(ChapterPageCtr, Arabic));</pre>
1.30 ! cvs 3055:
! 3056: <p>Thus, the presentation box contains the number of the chapter in
! 3057: upper-case roman numerals followed by a hyphen and the number of the page
! 3058: within the chapter in arabic numerals.</p>
1.18 cvs 3059: </blockquote>
1.30 ! cvs 3060:
1.18 cvs 3061: <blockquote class="example">
1.30 ! cvs 3062: <p><strong>Example:</strong></p>
! 3063:
! 3064: <p>To count tables and figures together in a document of the chapter type, a
! 3065: counter could be defined using:</p>
! 3066: <pre>CommonCtr : SET 0 ON Chapter ADD 1 ON Table
1.18 cvs 3067: ADD 1 ON Figure;</pre>
3068: </blockquote>
3069: </div>
1.1 cvs 3070:
1.18 cvs 3071: <div class="subsection">
1.30 ! cvs 3072: <h3><a name="sectc425">Presentation constants</a></h3>
1.1 cvs 3073:
1.30 ! cvs 3074: <p>Presentation constants are used in the definition of the content of
1.18 cvs 3075: presentation boxes. This content is used in <a href="#sectc426">variable
3076: definitions</a> and in the <a href="#sectc4231"><tt>Content</tt> rule</a>. The
1.1 cvs 3077: only presentation constants which can be used are character strings,
1.2 cvs 3078: mathematical symbols, graphical elements, and pictures, that is to say, base
1.18 cvs 3079: elements.</p>
1.30 ! cvs 3080:
! 3081: <p>Constants can be defined directly in the variables or presentation boxes
1.18 cvs 3082: (<tt>Content</tt> rule) which use them. But it is only necessary them to
1.1 cvs 3083: declare once, in the constant declaration section, even though they are used
3084: in many variables or boxes. Thus, each declared constant has a name, which
3085: allows it to be designated whenever it is used, a type (one of the four base
3086: types) and a value (a character string or a single character for mathematical
1.18 cvs 3087: symbols and graphical elements).</p>
1.30 ! cvs 3088:
! 3089: <p>The constant declarations appear after the keyword <tt>CONST</tt>. Each
1.1 cvs 3090: declaration is composed of the name of the constant, an equals sign, a keyword
1.18 cvs 3091: representing its type (<tt>Text</tt>, <tt>Symbol</tt>, <tt>Graphics</tt> or
3092: <tt>Picture</tt>) and the string representing its value. A semi-colon
3093: terminates each declaration.</p>
1.30 ! cvs 3094:
! 3095: <p>In the case of a character string, the keyword <tt>Text</tt> can be
! 3096: followed by the name of an alphabet (for example, <tt>Greek</tt> or
! 3097: <tt>Latin</tt>) in which the constant's text should be expressed. If the
! 3098: alphabet name is absent, the Latin alphabet is used. When the alphabet name
! 3099: is present, only the first letter of the alphabet name is interpreted. Thus,
! 3100: the words <tt>Greek</tt> and <tt>Grec</tt> designate the same alphabet. In
! 3101: current versions of Thot, only the Greek and Latin alphabets are
! 3102: available.</p>
1.18 cvs 3103: <pre> 'CONST' ConstSeq
1.30 ! cvs 3104: ConstSeq = Const < Const > .
1.1 cvs 3105: Const = ConstID '=' ConstType ConstValue ';' .
3106: ConstID = NAME .
3107: ConstType ='Text' [ Alphabet ] / 'Symbol' /
3108: 'Graphics' / 'Picture' .
3109: ConstValue = STRING .
1.18 cvs 3110: Alphabet = NAME .</pre>
1.30 ! cvs 3111:
! 3112: <p>For character strings in the Latin alphabet (ISO Latin-1 character set),
1.1 cvs 3113: characters having codes higher than 127 (decimal) are represented by their
1.18 cvs 3114: code in octal.</p>
1.30 ! cvs 3115:
! 3116: <p>In the case of a symbol or graphical element, the value only contains a
! 3117: single character, between apostrophes, which indicates the form of the element
! 3118: which must be drawn in the box whose content is the constant. The symbol or
1.1 cvs 3119: graphical element takes the dimensions of the box, which are determined by the
1.18 cvs 3120: <tt>Height</tt> and <tt>Width</tt> rules. See <a href="#sectb72">table of
3121: codes</a> for the symbols and graphical elements.</p>
1.30 ! cvs 3122:
1.18 cvs 3123: <blockquote class="example">
1.30 ! cvs 3124: <p><strong>Example:</strong></p>
! 3125:
! 3126: <p>The constants ``Summary:'' and fraction bar, which were described
! 3127: earlier, are declared:</p>
! 3128: <pre>CONST
1.1 cvs 3129: SummaryConst = Text 'Summary:';
1.18 cvs 3130: Bar = Graphics 'h';</pre>
3131: </blockquote>
3132: </div>
1.1 cvs 3133:
1.18 cvs 3134: <div class="subsection">
1.30 ! cvs 3135: <h3><a name="sectc426">Variables</a></h3>
1.1 cvs 3136:
1.30 ! cvs 3137: <p>Variables permit the definition of computed content for presentation boxes.
! 3138: A variable is associated with a presentation box by a <tt>Content</tt> rule;
! 3139: but before being used in a <tt>Content</tt> rule, a variable can be defined in
! 3140: the <tt>VAR</tt> section. It is also possible to define a variable at the
! 3141: time of its use in a <tt>Content</tt> rule, as can be done with a
! 3142: constant.</p>
! 3143:
! 3144: <p>A variable has a name and a value which is a character string resulting
! 3145: from the concatenation of the values of a sequence of functions. Each
! 3146: variable declaration is composed of the variable name followed by a colon and
! 3147: the sequence of functions which produces its value, separated by spaces. Each
1.18 cvs 3148: declaration is terminated by a semi-colon.</p>
3149: <pre> 'VAR' VarSeq
1.30 ! cvs 3150: VarSeq = Variable < Variable > .
1.1 cvs 3151: Variable = VarID ':' FunctionSeq ';' .
3152: VarID = NAME .
1.30 ! cvs 3153: FunctionSeq = Function < Function > .</pre>
! 3154:
! 3155: <p>Several functions are available. The first two return, in the form of a
1.18 cvs 3156: character string, the current date. <tt>DATE</tt> returns the date in
3157: English, while <tt>FDATE</tt> returns the date in french.</p>
1.30 ! cvs 3158:
! 3159: <p>Two other functions, <tt>DocName</tt> and <tt>DirName</tt>, return the
1.18 cvs 3160: document name and the directory where the document is stored.</p>
1.30 ! cvs 3161:
! 3162: <p>Function <tt>ElemName</tt> returns the type of the element which created
! 3163: the presentation box whose contents are the variable.</p>
! 3164:
! 3165: <p>Another function simply returns the value of a presentation constant. For
! 3166: any constant declared in the <tt>CONST</tt> section, it is sufficient to give
! 3167: the name of the constant. Otherwise, the type and value of the constant must
! 3168: be given, using the same form as in a <a href="#sectc425">constant
1.18 cvs 3169: declaration</a>. If the constant is not of type text, (types <tt>Symbol</tt>,
3170: <tt>Graphics</tt> or <tt>Picture</tt>), it must be alone in the variable
3171: definition; only constants of type <tt>Text</tt> can be mixed with other
3172: functions.</p>
1.30 ! cvs 3173:
! 3174: <p>It is also possible to obtain the value of an attribute, simply by
! 3175: mentioning the attribute's name. The value of this function is the value of
! 3176: the attribute for the element which created the presentation box whose
! 3177: contents are the variable. If the creating element does not have the
! 3178: indicated attribute, the value is an empty string. In the case of a numeric
! 3179: attribute, the attribute is translated into a decimal number in arabic
! 3180: numerals. If another form is desired, the <tt>VALUE</tt> function must be
! 3181: used.</p>
! 3182:
! 3183: <p>The last available function returns, as a character string, the value of a
1.1 cvs 3184: counter, an attribute or a page number. This value can be presented in
1.18 cvs 3185: different styles. The keyword <tt>VALUE</tt> is followed (between
1.1 cvs 3186: parentheses) by the name of the counter, the name of the attribute, or the
1.18 cvs 3187: keyword <tt>PageNumber</tt> and the desired style, the two parameters being
1.1 cvs 3188: separated by a comma. The style is a keyword which indicates whether the
1.18 cvs 3189: value should be presented in arabic numerals (<tt>Arabic</tt>), lower-case
3190: roman numerals (<tt>LRoman</tt>), or upper-case roman numerals
3191: (<tt>URoman</tt>), or by an upper-case letter (<tt>Uppercase</tt>) or
3192: lower-case letter (<tt>Lowercase</tt>).</p>
1.30 ! cvs 3193:
! 3194: <p>For a page counter, the keyword <tt>PageNumber</tt> can be followed,
! 3195: between parentheses, by the name of the view from which to obtain the page
! 3196: number. By default, the first view declared in the <tt>VIEWS</tt> section is
! 3197: used. The value obtained is the number of the page on which is found the
! 3198: element that is using the variable in a <tt>Content</tt> rule.</p>
! 3199:
! 3200: <p>For an ordinary counter, the name of the counter can be preceded by the
1.18 cvs 3201: keyword <tt>MaxRangeVal</tt> or <tt>MinRangeVal</tt>. These keywords mean
1.1 cvs 3202: that the value returned by the function is the maximum (minimum resp.) value
3203: taken by the counter in the whole document, not the value for the element
1.18 cvs 3204: concerned by the function.</p>
3205: <pre> Function = 'DATE' / 'FDATE' /
1.1 cvs 3206: 'DocName' / 'DirName' /
3207: 'ElemName' / 'AttributeName' /
3208: ConstID / ConstType ConstValue /
3209: AttrID /
3210: 'VALUE' '(' PageAttrCtr ','
3211: CounterStyle ')' .
1.6 cvs 3212: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
1.1 cvs 3213: [ MinMax ] CounterID / AttrID .
3214: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
3215: 'Uppercase' / 'Lowercase' .
1.18 cvs 3216: MinMax = 'MaxRangeVal' / 'MinRangeVal' .</pre>
1.30 ! cvs 3217:
1.18 cvs 3218: <blockquote class="example">
1.30 ! cvs 3219: <p><strong>Example:</strong></p>
! 3220:
! 3221: <p>To make today's date appear at the top of the first page of a report, a
! 3222: <a href="#sectc4232"><tt>CREATE</tt> rule</a> associated with the
! 3223: Report_Title element type generates a presentation box whose content
! 3224: (specified by the <tt>Content</tt> rule of that presentation box) is the
! 3225: variable:</p>
! 3226: <pre>VAR
1.18 cvs 3227: Todays_date : TEXT 'Version of ' DATE;</pre>
1.30 ! cvs 3228:
! 3229: <p>To produce, before each section title, the chapter number (in upper-case
! 3230: roman numerals) followed by the section number (in arabic numerals), two
! 3231: counters must be defined:</p>
! 3232: <pre>COUNTERS
1.1 cvs 3233: ChapterCtr : RANK OF Chapter;
1.18 cvs 3234: SectionCtr : RANK OF Section;</pre>
1.30 ! cvs 3235:
! 3236: <p>and the Section_Title element must create a presentation box whose
! 3237: content is the variable</p>
! 3238: <pre>VAR
1.1 cvs 3239: SectionNum : VALUE (ChapterCtr, URoman) TEXT '-'
1.18 cvs 3240: VALUE (SectionCtr, Arabic);</pre>
1.30 ! cvs 3241:
! 3242: <p>In order to make the page number on which each section begins appear in
! 3243: the table of contents view next to the section title, each Section_Title
! 3244: element must create a presentation box, visible only in the table of
! 3245: contents view, whose content is the variable:</p>
! 3246: <pre>VAR
1.1 cvs 3247: TitlePageNume :
1.18 cvs 3248: VALUE (PageNumber(Full_text), Arabic);</pre>
3249: </blockquote>
3250: </div>
1.1 cvs 3251:
1.18 cvs 3252: <div class="subsection">
1.30 ! cvs 3253: <h3><a name="sectc427">Default presentation rules</a></h3>
1.1 cvs 3254:
1.30 ! cvs 3255: <p>In order to avoid having to specify, for each element type defined in the
1.1 cvs 3256: structure schema, values for every one of the numerous presentation
3257: parameters, the presentation schema allows the definition of a set of default
3258: presentation rules. These rules apply to all the boxes of the elements
3259: defined in the structure schema and to the presentation boxes and page layout
3260: boxes defined in the presentation schema. Only rules which differ from these
1.18 cvs 3261: default need to be specified in other sections of the presentation schema.</p>
1.30 ! cvs 3262:
! 3263: <p>For the primary view, the default rules can define every presentation
1.18 cvs 3264: parameter, but not the <a href="#presfunct">presentation functions</a> or the
3265: <a href="#sectc4223">linebreaking conditions</a> (the <tt>NoBreak1</tt>,
3266: <tt>NoBreak2</tt>, and <tt>Gather</tt> rules).</p>
1.30 ! cvs 3267:
! 3268: <p>In a presentation schema, the default presentation rules section is
! 3269: optional; in this case, the <tt>DEFAULT</tt> keyword is also absent and the
! 3270: following rules are considered to be the default rules:</p>
1.26 cvs 3271: <pre> Visibility: Enclosing =;
3272: VertRef: * . Left;
3273: HorizRef: Enclosed . HRef;
3274: Height: Enclosed . Height;
3275: Width: Enclosed . Width;
3276: VertPos: Top = Previous . Bottom;
3277: HorizPos: Left = Enclosing . Left;
3278: MarginTop: 0;
3279: MarginRight: 0;
3280: MarginBottom: 0;
3281: MarginLeft: 0;
3282: PaddingTop: 0;
3283: PaddingRight: 0;
3284: PaddingBottom: 0;
3285: PaddingLeft: 0;
3286: BorderTopWidth: 0;
3287: BorderRightWidth: 0;
3288: BorderBottomWidth: 0;
3289: BorderLeftWidth: 0;
3290: BorderTopColor: Foreground;
3291: BorderRightColor: Foreground;
3292: BorderBottomColor: Foreground;
3293: BorderLeftColor: Foreground;
3294: BorderTopStyle: None;
3295: BorderRightStyle: None;
3296: BorderBottomStyle: None;
3297: BorderLeftStyle: None;
3298: VertOverflow: No;
3299: HorizOverflow: No;
3300: Size: Enclosing =;
3301: Style: Enclosing =;
3302: Weight: Enclosing =;
3303: Font: Enclosing =;
3304: Underline: Enclosing =;
3305: Thickness: Enclosing =;
3306: Indent: Enclosing =;
3307: LineSpacing: Enclosing =;
3308: Adjust: Enclosing =;
3309: Justify: Enclosing =;
3310: Hyphenate: Enclosing =;
3311: PageBreak: Yes;
3312: LineBreak: Yes;
3313: InLine: Yes;
3314: Depth: 0;
3315: LineStyle: Enclosing =;
3316: LineWeight: Enclosing =;
3317: FillPattern: Enclosing =;
3318: Background: Enclosing =;
3319: Foreground: Enclosing =;</pre>
1.30 ! cvs 3320:
! 3321: <p>If other values are desired for the default rules, they must be defined
1.1 cvs 3322: explicitly in the default rules section. In fact, it is only necessary to
3323: define those default rules which differ from the ones above, since the rules
1.18 cvs 3324: above will be used whenever a rule is not explicitly named.</p>
1.30 ! cvs 3325:
! 3326: <p>Default rules for views other than the primary view can also be specified.
1.1 cvs 3327: Otherwise, the default rules for the primary views are applied to the other
1.18 cvs 3328: views.</p>
1.30 ! cvs 3329:
! 3330: <p>Default rules are expressed in the same way as <a
! 3331: href="#sectc4215">explicit rules for document elements</a>.</p>
1.18 cvs 3332: </div>
1.1 cvs 3333:
1.18 cvs 3334: <div class="subsection">
1.30 ! cvs 3335: <h3><a name="sectc428">Presentation and page layout boxes</a></h3>
1.1 cvs 3336:
1.30 ! cvs 3337: <p>The presentation process uses elements which are not part of the logical
1.1 cvs 3338: structure of the document, such as pages (which are the page layout boxes) or
3339: alternatively, rules, numbers, or words introducing certain parts of the
3340: document, such as ``Summary'', ``Appendices'', ``Bibliography'', etc. (which
1.18 cvs 3341: are presentation boxes).</p>
1.30 ! cvs 3342:
! 3343: <p>After the word <tt>BOXES</tt>, each presentation or page layout box is
! 3344: defined by its name and a sequence of presentation rules which indicate how
! 3345: they must be displayed. These rules are the same as those which define the
! 3346: boxes associated with element of the logical structure of the document, with a
1.18 cvs 3347: single exception, the <a href="#sectc4231"><tt>Content</tt> rule</a> which is
1.1 cvs 3348: used only to specify the content of presentation boxes. The content of boxes
3349: associated with elements of the document structure is defined in each document
3350: or object and thus is not specified in the presentation schema, which applies
1.18 cvs 3351: to all documents or objects of a class.</p>
1.30 ! cvs 3352:
! 3353: <p>Among the rules which define a presentation box, certain ones can refer to
1.1 cvs 3354: another presentation box (for example, in their positional rules). If the
3355: designated box is defined after the box which designates it, a
1.18 cvs 3356: <tt>FORWARD</tt> instruction followed by the name of the designated box must
3357: appear before the designation.</p>
3358: <pre> 'BOXES' BoxSeq
1.30 ! cvs 3359: BoxSeq = Box < Box > .
1.1 cvs 3360: Box ='FORWARD' BoxID ';' /
3361: BoxID ':' ViewRuleSeq .
1.18 cvs 3362: BoxID = NAME .</pre>
3363: </div>
1.1 cvs 3364:
1.18 cvs 3365: <div class="subsection">
1.30 ! cvs 3366: <h3><a name="sectc429">Presentation of structured elements</a></h3>
1.1 cvs 3367:
1.30 ! cvs 3368: <p>After the words <tt>RULES</tt>, the presentation schema gives the
! 3369: presentation rules that apply to the elements whose types are defined in the
! 3370: structure schema. Only those rules which differ from the <a
1.18 cvs 3371: href="#sectc427">default</a> must be specified in the <tt>RULES</tt>
3372: section.</p>
1.30 ! cvs 3373:
! 3374: <p>The rule definitions for each element type are composed of the name of the
1.1 cvs 3375: element type (as specified in the structure schema) followed by a colon and
1.18 cvs 3376: the set of rules specific to that type.</p>
1.30 ! cvs 3377:
! 3378: <p>The type name can be preceded by a star in the special case where the
1.18 cvs 3379: structure schema defines an <a href="#sectd3284">inclusion</a> without
1.1 cvs 3380: expansion (or with partial expansion) of a type with the same name as an
1.18 cvs 3381: element of defined in the structure schema.</p>
1.30 ! cvs 3382:
! 3383: <p>In the case where the element is a <a href="#sectd3285">mark pair</a>, but
1.18 cvs 3384: only in this case, the type name can be preceded by the keywords
3385: <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
3386: that follow apply to the first or second mark of the pair.</p>
3387: <pre> 'RULES' PresentSeq
1.30 ! cvs 3388: PresentSeq = Present < Present > .
1.6 cvs 3389: Present = [ '*' ] [ FirstSec ] ElemID ':'
3390: ViewRuleSeq .
1.18 cvs 3391: FirstSec = 'First' / 'Second' .</pre>
1.30 ! cvs 3392:
! 3393: <p>A presentation schema can define presentation rules for base elements,
! 3394: which are defined implicitly in the structure schemas. In the English version
! 3395: of the presentation schema compiler, the base type names are the same as in
! 3396: the S language, but they are terminated by the <tt>_UNIT</tt> suffix:
1.18 cvs 3397: <tt>TEXT_UNIT</tt>, <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>,
3398: <tt>GRAPHICS_UNIT</tt>. The base type names are written in upper-case
3399: letters.</p>
3400: </div>
3401:
3402: <div class="subsection">
1.30 ! cvs 3403: <h3><a name="sectc4210">Logical attribute presentation</a></h3>
1.18 cvs 3404:
1.30 ! cvs 3405: <p>After the keyword <tt>ATTRIBUTES</tt>, all attributes which are to have
! 3406: some effect on the presentation of the element to which they are attached must
! 3407: be mentioned, along with the corresponding presentation rules. This is true
! 3408: for both global attributes (which can be attached to all element types) and
! 3409: local attributes (which can only be attached to certain element types).</p>
! 3410:
! 3411: <p>Also mentioned in this section are attributes which imply an effect on
1.1 cvs 3412: elements in the subtree of the element to which they are attached. The
3413: presentation of these descendants can be modified as a function of the value
3414: of the attribute which they inherit, just as if it was attached to them
1.18 cvs 3415: directly.</p>
1.30 ! cvs 3416:
! 3417: <p>The specification for each attribute includes the attribute's name,
! 3418: followed by an optional value specification and, after a colon, a set of
! 3419: rules. The set of rules must contain at least one rule.</p>
! 3420:
! 3421: <p>When there is no value specification, the rules are applied to all elements
1.1 cvs 3422: which carry the attribute, no matter what their value. When the rules must
3423: only apply when the attribute has certain values, these values must be
1.18 cvs 3424: specified. Thus, the same attribute can appear in the <tt>ATTRIBUTES</tt>
1.1 cvs 3425: section several times, with each appearance having a different value
3426: specification. However, reference attributes never have a value specification
1.18 cvs 3427: and, as a result, can only appear once in the <tt>ATTRIBUTES</tt> section.</p>
1.30 ! cvs 3428:
! 3429: <p>To specify that the presentation rules apply to some of the descendants of
! 3430: the element having the attribute, the name of the affected element type is
! 3431: given, between parentheses, after the attribute name. This way, the
! 3432: presentation rules for the attribute will be applied to the element having the
! 3433: attribute, if it is of the given type, and to all of its descendants of the
! 3434: given type. In the case where this type is a <a href="#sectd3285">mark
! 3435: pair</a>, but only in this case, the type name can be preceded by the keywords
! 3436: <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
! 3437: that follow apply to the first or second mark of the pair. If the rule must
! 3438: apply to several different element types, the specification must be repeated
! 3439: for each element type.</p>
! 3440:
! 3441: <p>The specification of values for which the presentation rules will be
! 3442: applied varies according to the type of the attribute:</p>
1.18 cvs 3443: <dl>
1.30 ! cvs 3444: <dt>numeric attribute</dt>
! 3445: <dd>If the rules are to apply for one value of the attribute, then the
! 3446: attribute name is followed by an equals sign and this value. If the
! 3447: rules are to apply for all values less than (or greater than) a
! 3448: threshold value, non-inclusive, the attribute name followed by a '<'
! 3449: sign (or a '>' sign, respectively) and the threshold value. If the
! 3450: rules must apply to a range of values, the attribute name is followed by
! 3451: the word '<tt>IN</tt>' and the two bounds of the range, enclosed in
! 3452: brackets and separated by two periods ('<tt>..</tt>'). In the case of
! 3453: ranges, the values of the bounds are included in the range.
! 3454: <p>The threshold value in the comparisons can be the value of an
! 3455: attribute attached to an ancestor element. In this case, the attribute
! 3456: name is given instead of a constant value.</p>
! 3457: <p>It is also possible to write rules which apply only when a comparison
! 3458: between two different attributes of the element's ancestors is true. In
! 3459: this case, the first attribute name is followed by a comparison keyword
! 3460: and the name of the second attribute. The comparison keywords are
! 3461: <tt>EQUAL</tt> (simple equality), <tt>LESS</tt> (non-inclusive less
! 3462: than), and <tt>GREATER</tt> (non-inclusive greater than).</p>
! 3463: </dd>
! 3464: <dt>text attribute</dt>
! 3465: <dd>If the rules are to apply for one value of the attribute, then the
! 3466: attribute name is followed by an equals sign and this value.</dd>
! 3467: <dt>reference attribute</dt>
! 3468: <dd>There is never a value specification; the rules apply no matter what
! 3469: element is designated by the attribute.</dd>
! 3470: <dt>enumerated attribute</dt>
! 3471: <dd>If the rules are to apply for one value of the attribute, then the
! 3472: attribute name is followed by an equals sign and this value.</dd>
1.18 cvs 3473: </dl>
1.30 ! cvs 3474:
! 3475: <p>The order in which the rules associated with a numeric attribute are
! 3476: defined is important. When multiple sets of rules can be applied, the first
! 3477: set declared is the one used.</p>
! 3478:
! 3479: <p>Rules for attributes have priority over both default rules and rules
1.1 cvs 3480: associated with element types. The attribute rules apply to the element to
3481: which the attribute is attached. It is the rules which apply to the
3482: surrounding elements (and especially to the descendants) which determine the
3483: effect of the attribute rules on the environment ( and especially on the
1.18 cvs 3484: terminal elements of the structure).</p>
3485: <pre> 'ATTRIBUTES' PresAttrSeq
1.30 ! cvs 3486: PresAttrSeq = PresAttr < PresAttr > .
1.1 cvs 3487: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
3488: [ AttrRelation ] ':' ViewRuleSeq .
3489: AttrID = NAME .
3490: AttrRelation ='=' AttrVal /
1.30 ! cvs 3491: '>' [ '-' ] MinValue /
1.1 cvs 3492: '<' [ '-' ] MaxValue /
3493: 'IN' '[' [ '-' ] LowerBound '..'
3494: [ '-' ] UpperBound ']' /
3495: 'GREATER' AttrID /
3496: 'EQUAL' AttrID /
3497: 'LESS' AttrID .
3498: AttrVal = [ '-' ] EqualNum / EqualText /
3499: AttrValue .
3500: MinValue = NUMBER .
3501: MaxValue = NUMBER .
3502: LowerBound = NUMBER .
3503: UpperBound = NUMBER.
3504: EqualNum = NUMBER .
3505: EqualText = STRING .
1.18 cvs 3506: AttrValue = NAME .</pre>
1.30 ! cvs 3507:
! 3508: <p>In presentation rules associated with a numeric attribute (and only in such
1.1 cvs 3509: rules), the attribute name can be used in place of a numeric value. In this
3510: case, the value of the attribute is used in the application of the rule. Thus,
3511: the attribute can represent a relation between the size of two boxes, the
3512: height and width of a box, the height of an area where page breaks are
3513: prohibited, the distance between two boxes, the position of the reference axis
3514: of a box, the interline spacing, the indentation of the first line, the
1.18 cvs 3515: visibility, the depth (z-order), or the character set.</p>
1.30 ! cvs 3516:
! 3517: <p>The presentation rules associated with reference attributes, it is possible
! 3518: to use the element designated by the attribute as a reference box in a
! 3519: positional or extent rule. This element is represented in the <a
1.18 cvs 3520: href="#sectc4218">position</a> or <a href="#sectc4219">extent</a> rule by the
3521: keyword <tt>Referred</tt>.</p>
1.30 ! cvs 3522:
1.18 cvs 3523: <blockquote class="example">
1.30 ! cvs 3524: <p><strong>Example:</strong></p>
! 3525:
! 3526: <p>In all structure schemas, there is a global Language attribute defined as
! 3527: follows:</p>
! 3528: <pre>ATTR
1.18 cvs 3529: Language = TEXT;</pre>
1.30 ! cvs 3530:
! 3531: <p>The following rules would make French text be displayed in roman
! 3532: characters and English text be displayed in italics:</p>
! 3533: <pre>ATTRIBUTES
1.1 cvs 3534: Language = 'French' :
1.6 cvs 3535: Style : Roman;
1.1 cvs 3536: Language = 'English' :
1.18 cvs 3537: Style : Italics;</pre>
1.30 ! cvs 3538:
! 3539: <p>Using these rules, when the user puts the Language attribute with the
! 3540: value 'English' on the summary of a document, every character string
! 3541: (terminal elements) contained in the summary are displayed in italics. See
! 3542: the <a href="#sectd42252"><tt>Style</tt> rule</a>.</p>
1.18 cvs 3543: </blockquote>
1.30 ! cvs 3544:
1.18 cvs 3545: <blockquote class="example">
1.30 ! cvs 3546: <p><strong>Example:</strong></p>
! 3547:
! 3548: <p>A numeric attribute representing the importance of the part of the
! 3549: document to which it is attached can be defined:</p>
! 3550: <pre>ATTR
1.18 cvs 3551: Importance = INTEGER;</pre>
1.30 ! cvs 3552:
! 3553: <p>In the presentation schema, the importance of an element is reflected in
! 3554: the choice of character size, using the following rules.</p>
! 3555: <pre>ATTRIBUTES
1.1 cvs 3556: Importance < 2 :
3557: Size : 1;
3558: Importance IN [2..4] :
3559: Size : Importance;
3560: Importance = 10 :
3561: Size : 5;
1.30 ! cvs 3562: Importance > 4 :
1.18 cvs 3563: Size : 4;</pre>
1.30 ! cvs 3564:
! 3565: <p>Thus, the character size corresponds to the value of the Importance
! 3566: attribute; its value is</p>
! 3567: <ul>
! 3568: <li>the value of the Importance attribute when the value is between 2 and
! 3569: 4 (inclusive),</li>
! 3570: <li>1, when the value of the Importance attribute is less than 2,</li>
! 3571: <li>4, when the value of the Importance attribute is greater than 4,</li>
! 3572: <li>5, when the value of the Importance attribute is 10.</li>
! 3573: </ul>
! 3574:
! 3575: <p>The last case (value 5) must be defined before the case which handles all
! 3576: Importance values greater than 4, because the two rules are not disjoint and
! 3577: the first one defined will have priority. Otherwise, when the Importance
! 3578: attribute has value 10, the font size will be 4.</p>
1.18 cvs 3579: </blockquote>
1.30 ! cvs 3580:
1.18 cvs 3581: <blockquote class="example">
1.30 ! cvs 3582: <p><strong>Example:</strong></p>
! 3583:
! 3584: <p>Suppose the structure defines a list element which can have an attribute
! 3585: defining the type of list (numbered or not):</p>
! 3586: <pre>STRUCT
1.1 cvs 3587: list (ATTR list_type = enumeration, dash)
1.18 cvs 3588: = LIST OF (list_item = TEXT);</pre>
1.30 ! cvs 3589:
! 3590: <p>Then, the presentation schema could use the attribute placed on the list
! 3591: element to put either a dash or a number before the each element of the
! 3592: list:</p>
! 3593: <pre>ATTRIBUTES
1.1 cvs 3594: list_type (list_item) = enumeration :
3595: CreateBefore (NumberBox);
3596: list_type (list_item) = dash :
1.18 cvs 3597: CreateBefore (DashBox);</pre>
3598: </blockquote>
1.30 ! cvs 3599:
1.18 cvs 3600: <blockquote class="example">
1.30 ! cvs 3601: <p><strong>Example:</strong></p>
! 3602:
! 3603: <p>Suppose that two attributes are defined in the structure schema. The
! 3604: first is a numeric global attribute called ``version''. The other is a
! 3605: local attribute defined on the root of the document called
! 3606: ``Document_version'':</p>
! 3607: <pre>STRUCTURE Document
1.1 cvs 3608: ATTR
3609: version = INTEGER;
3610: STRUCT
3611: Document (ATTR Document_version = INTEGER) =
3612: BEGIN
3613: SomeElement ;
3614: ...
3615: SomeOtherElement ;
3616: END ;
1.18 cvs 3617: ...</pre>
1.30 ! cvs 3618:
! 3619: <p>These attributes can be used in the presentation schema to place change
! 3620: bars in the margin next to elements whose version attribute has a value
! 3621: equal to the Document_version attribute of the root and to place a star in
! 3622: margin of elements whose version attribute is less than the value of the
! 3623: root's Document_version attribute:</p>
! 3624: <pre>ATTRIBUTES
1.1 cvs 3625: version EQUAL Document_version :
3626: CreateBefore (ChangeBarBox) ;
3627: version LESS Document_version :
1.18 cvs 3628: CreateBefore (StarBox) ;</pre>
3629: </blockquote>
3630: </div>
1.1 cvs 3631:
1.18 cvs 3632: <div class="subsection">
1.30 ! cvs 3633: <h3><a name="sectc4212">Value transmission rules</a></h3>
1.1 cvs 3634:
1.30 ! cvs 3635: <p>The last section of a presentation schema, which is optional, serves to
1.1 cvs 3636: defines the way in which a document transmits certain values to its
1.18 cvs 3637: sub-documents. A sub-document is an document <a
3638: href="#inclusion">included</a> without expansion or with partial expansion.
1.1 cvs 3639: The primary document can transmit to its sub-documents the values of certain
3640: counters or the textual content of certain of its elements, as a function of
1.18 cvs 3641: their type.</p>
1.30 ! cvs 3642:
! 3643: <p>The sub-documents receive these values in attributes which must be defined
! 3644: in their structure schema as local attributes of the root element. The types
! 3645: of these attributes must correspond to the type of the value which they
! 3646: receive: numeric attributes for receiving the value of a counter, textual
! 3647: attributes for receiving the content of an element.</p>
! 3648:
! 3649: <p>In the structure schema of the primary document, there appears at the end,
1.18 cvs 3650: after the <tt>TRANSMIT</tt> keyword, a sequence of transmission rules. Each
1.1 cvs 3651: rule begins with the name of the counter to transmit or of the element type
3652: whose textual content will be transmitted. This name is followed by the
1.18 cvs 3653: keyword <tt>To</tt> and the name of the attribute of the sub-document to which
1.1 cvs 3654: the value is transmitted. The sub-document class is indicated between
3655: parentheses after the name of the attribute. The transmission rule ends with
1.18 cvs 3656: a semicolon.</p>
1.30 ! cvs 3657: <pre> TransmitSeq = Transmit < Transmit > .
1.1 cvs 3658: Transmit = TypeOrCounter 'To' ExternAttr
3659: '(' ElemID ')' ';' .
3660: TypeOrCounter = CounterID / ElemID .
1.18 cvs 3661: ExternAttr = NAME .</pre>
1.30 ! cvs 3662:
1.18 cvs 3663: <blockquote class="example">
1.30 ! cvs 3664: <p><strong>Example:</strong></p>
! 3665:
! 3666: <p>Consider a Book document class which includes instances of the Chapter
! 3667: document class. These classes might have the following schemas:</p>
! 3668: <pre>STRUCTURE Book
1.1 cvs 3669: STRUCT
3670: Book = BEGIN
3671: Title = Text;
3672: Body = LIST OF (Chapter INCLUDED);
3673: END;
3674: ...
3675:
3676: STRUCTURE Chapter
3677: STRUCT
3678: Chapter (ATTR FirstPageNum = Integer;
3679: ChapterNum = Integer;
3680: CurrentTitle = Text) =
1.6 cvs 3681: BEGIN
3682: ChapterTitle = Text;
3683: ...
3684: END;
1.18 cvs 3685: ...</pre>
1.30 ! cvs 3686:
! 3687: <p>Then the presentation schema for books could define chapter and page
! 3688: counters. The following transmission rules in the book presentation schema
! 3689: would transmit values for the three attributes defined at the root of each
! 3690: chapter sub-document.</p>
! 3691: <pre>PRESENTATION Book;
1.1 cvs 3692: VIEWS
3693: Full_text;
3694: COUNTERS
3695: ChapterCtr: Rank of Chapter;
3696: PageCtr: Rank of Page(Full_text);
3697: ...
3698: TRANSMIT
3699: PageCtr TO FirstPageNum(Chapter);
3700: ChapterCtr TO ChapterNum(Chapter);
3701: Title TO CurrentTitle(Chapter);
1.18 cvs 3702: END</pre>
1.30 ! cvs 3703:
! 3704: <p>Thus, each chapter included in a book can number its pages as a function
! 3705: of the number of pages preceding it in the book, can make the chapter's
! 3706: number appear before the number of each of its sections, or can place the
! 3707: title of the book at the top of each page.</p>
1.18 cvs 3708: </blockquote>
3709: </div>
1.1 cvs 3710:
1.18 cvs 3711: <div class="subsection">
1.30 ! cvs 3712: <h3><a name="sectc4213">Presentation rules</a></h3>
1.1 cvs 3713:
1.30 ! cvs 3714: <p>Whether defining the appearance of a presentation or page layout box, an
1.1 cvs 3715: element type, or an attribute value, the set of presentation rules that apply
1.18 cvs 3716: is always defined in the same way.</p>
1.30 ! cvs 3717:
! 3718: <p>Normally, a set of presentation rules is placed between the keywords
1.18 cvs 3719: <tt>BEGIN</tt> and <tt>END</tt>, the keyword <tt>END</tt> being followed by a
1.1 cvs 3720: semicolon. The first section of this block defines the rules that apply to
1.18 cvs 3721: the primary view, if the <a href="#sectc427">default rules</a> are not
1.1 cvs 3722: completely suitable. Next comes the rules which apply to specific other
3723: views, with a rule sequence for each view for which the default rules are not
3724: satisfactory. If the default rules are suitable for the non-primary views,
3725: there will not be any specific rules for these views. If there is only one
1.18 cvs 3726: rule which applies to all views then the keywords <tt>BEGIN</tt> and
3727: <tt>END</tt> need not appear.</p>
1.30 ! cvs 3728:
! 3729: <p>For each view, it is only necessary to specify those rules which differ
! 3730: from the default rules for the view, so that for certain views (or even all
! 3731: views), there may be no specific rules.</p>
! 3732:
! 3733: <p>The specific rules for a non-primary view are introduced by the <a
1.18 cvs 3734: name="inkeyword"><tt>IN</tt> keyword</a>, followed by the view name. The
3735: rules for that view follow, delimited by the keywords <tt>BEGIN</tt> and
3736: <tt>END</tt>, or without these two keywords when there is only one rule.</p>
1.30 ! cvs 3737:
! 3738: <p><strong>Note:</strong> the view name which follows the <tt>IN</tt> keyword
1.1 cvs 3739: must not be the name of the primary view, since the rules for that view are
1.18 cvs 3740: found before the rules for the other views.</p>
1.30 ! cvs 3741:
! 3742: <p>Within each block concerning a view, other blocks can appear, delimited by
! 3743: the same keywords <tt>BEGIN</tt> and <tt>END</tt>. Each of these blocks
! 3744: gathers the presentation rules that apply, for a given view, only when a given
1.1 cvs 3745: condition is satisfied. Each block is preceded by a condition introduced by
1.18 cvs 3746: the <tt>IF</tt> keyword. If such a conditional block contains only one rule,
3747: the keywords <tt>BEGIN</tt> and <tt>END</tt> can be omitted.</p>
1.30 ! cvs 3748:
! 3749: <p>Although the syntax allows any presentation rule to appear in a conditional
1.18 cvs 3750: block, only <a href="#sectc4232">creation rules</a> are allowed after any
3751: condition; other rules are allowed only after conditions <tt>Within</tt> and
1.1 cvs 3752: ElemID. In addition, the following rules cannot be conditional:
1.18 cvs 3753: <tt>PageBreak, LineBreak, Inline, Gather</tt>.</p>
1.30 ! cvs 3754:
! 3755: <p>For a given view, the rules that apply without any condition must appear
1.1 cvs 3756: before the first conditional block. If some rules apply only when none of the
3757: specified condition holds, they are grouped in a block preceded by the keyword
1.18 cvs 3758: <tt>Otherwise</tt>, and that block must appear after the last conditionnal
3759: block concerning the same view.</p>
1.30 ! cvs 3760: <pre> ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 3761: 'END' ';' /
3762: ViewRules / CondRules / Rule .
3763: RulesAndCond = CondRules / Rule .
3764: ViewRules = 'IN' ViewID CondRuleSeq .
1.30 ! cvs 3765: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
1.1 cvs 3766: CondRules / Rule .
1.30 ! cvs 3767: CondRules = CondRule < CondRule >
1.1 cvs 3768: [ 'Otherwise' RuleSeq ] .
3769: CondRule = 'IF' ConditionSeq RuleSeq .
1.30 ! cvs 3770: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' /
1.18 cvs 3771: Rule .</pre>
1.30 ! cvs 3772:
1.18 cvs 3773: <blockquote class="example">
1.30 ! cvs 3774: <p><strong>Example:</strong></p>
! 3775:
! 3776: <p>The following rules for a report's title make the title visible in the
! 3777: primary view and invisible in the table of contents and in the formula views
! 3778: (see the <a href="#sectc4224"><tt>Visibility</tt> rule</a>).</p>
! 3779: <pre>Title : BEGIN
1.1 cvs 3780: Visibility : 1;
3781: ... {Other rules for the primary view}
3782: IN Table_of_contents
3783: Visibility : 0;
3784: IN Formulas
3785: Visibility : 0;
1.18 cvs 3786: END;</pre>
3787: </blockquote>
3788: </div>
1.1 cvs 3789:
1.18 cvs 3790: <div class="subsection">
1.30 ! cvs 3791: <h3><a name="sectc4214">Conditions applying to presentation rules</a></h3>
1.1 cvs 3792:
1.30 ! cvs 3793: <p>Many conditions can be applied to presentation rules. Conditions allow
1.1 cvs 3794: certain presentation rules to apply only in certain cases. These conditions
3795: can be based on the structural position of the element. They can be based on
3796: whether the element has references, and what type of references, whether the
3797: element has attributes, whether the element is empty or not. They can also be
1.18 cvs 3798: based on the value of a counter.</p>
1.30 ! cvs 3799:
! 3800: <p>It is possible to specify several conditions which must all be true for the
1.18 cvs 3801: rules to apply.</p>
1.30 ! cvs 3802:
! 3803: <p>A set of conditions is specified by the <tt>IF</tt> keyword. This keyword
! 3804: is followed by the sequence of conditions, separated by the <tt>AND</tt>
! 3805: keyword. Each condition is specified by a keyword which defines the condition
! 3806: type. In some cases, the keyword is followed by other data, which specify the
! 3807: condition more precisely.</p>
! 3808:
! 3809: <p>An elementary condition can be negative; it is then preceded by the
1.18 cvs 3810: <tt>NOT</tt> keyword.</p>
1.30 ! cvs 3811:
! 3812: <p>When the presentation rule(s) controlled by the condition apply to a
! 3813: reference element or a reference attribute, an elementary condition can also
! 3814: apply to element referred by this reference. The <tt>Target</tt> keyword is
! 3815: used for that purpose. It must appear before the keyword defining the
! 3816: condition type.</p>
1.18 cvs 3817: <pre> CondRule ='IF' ConditionSeq RuleSeq .
1.30 ! cvs 3818: ConditionSeq = Condition < 'AND' Condition > .
1.1 cvs 3819: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
3820: ConditionElem ='First' / 'Last' /
3821: [ 'Immediately' ] 'Within' [ NumParent ]
3822: ElemID [ ExtStruct ] /
3823: ElemID /
3824: 'Referred' / 'FirstRef' / 'LastRef' /
3825: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
3826: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
3827: 'UserPage' / 'StartPage' / 'ComputedPage' /
3828: 'Empty' /
3829: '(' [ MinMax ] CounterName CounterCond ')' /
3830: CondPage '(' CounterID ')' .
3831: NumParent = [ GreaterLess ] NParent .
1.30 ! cvs 3832: GreaterLess ='>' / '<' .
1.1 cvs 3833: NParent = NUMBER.
1.6 cvs 3834: ExtStruct ='(' ElemID ')' .
1.30 ! cvs 3835: CounterCond ='<' MaxCtrVal / '>' MinCtrVal /
1.1 cvs 3836: '=' EqCtrVal /
3837: 'IN' '[' ['-'] MinCtrBound '.' '.'
3838: ['-'] MaxCtrBound ']' .
3839: PageCond ='Even' / 'Odd' / 'One' .
3840: MaxCtrVal = NUMBER .
3841: MinCtrVal = NUMBER .
3842: EqCtrVal = NUMBER .
3843: MaxCtrBound = NUMBER .
1.18 cvs 3844: MinCtrBound = NUMBER .</pre>
1.1 cvs 3845:
1.18 cvs 3846: <div class="subsubsection">
3847: <h4><a name="sectd42141">Conditions based on the logical position of the
3848: element</a></h4>
1.30 ! cvs 3849:
! 3850: <p>The condition can be on the position of the element in the document's
! 3851: logical structure tree. It is possible to test whether the element is the
! 3852: first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
! 3853: not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>). These
1.18 cvs 3854: conditions can be associated only with <a href="#sectc4232">creation
3855: rules</a>.</p>
1.30 ! cvs 3856:
! 3857: <p>It is also possible to test if the element is contained in an element of a
1.18 cvs 3858: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). The type
3859: is indicated after the keyword <tt>Within</tt>. If that element type is
1.1 cvs 3860: defined in a structure schema which is not the one which corresponds to the
3861: presentation schema, the type name of this element must be followed, between
1.18 cvs 3862: parentheses, by the name of the structure schema which defines it.</p>
1.30 ! cvs 3863:
! 3864: <p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
1.18 cvs 3865: condition is satisfied only if the <em>parent</em> element has the type
3866: indicated. If the word <tt>Immediately</tt> is missing, the condition is
3867: satisfied if any <em>ancestor</em> has the type indicated.</p>
1.30 ! cvs 3868:
! 3869: <p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.1 cvs 3870: type. It specifies the number of ancestors of the indicated type that must be
3871: present for the condition to be satisfied. If the keyword
1.18 cvs 3872: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
3873: element must have the indicated type. The integer <i>n</i> must be positive
1.30 ! cvs 3874: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
1.1 cvs 3875: maximum or minimum number of ancestors. If these symbols are missing, the
1.18 cvs 3876: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
1.30 ! cvs 3877: this number is missing, it is equivalent to > 0.</p>
! 3878:
! 3879: <p>If the condition applies to presentation rules associated with an
! 3880: attribute, in the <tt>ATTRIBUTES</tt> section of the presentation schema, the
! 3881: condition can be simply an element name. Presentation rules are then executed
! 3882: only if the attribute is attached to an element of that type. The keyword
! 3883: <tt>NOT</tt> before the element name indicates that the presentation rules
! 3884: must be executed only if the element is not of the type indicated.</p>
1.18 cvs 3885: </div>
1.1 cvs 3886:
1.18 cvs 3887: <div class="subsubsection">
1.30 ! cvs 3888: <h4><a name="sectd42142">Conditions on references</a></h4>
! 3889:
! 3890: <p>References may be taken into account in conditions, which can be based on
! 3891: the fact that the element, or one of its ancestors, is designated by a at
! 3892: least one reference (<tt>Referred</tt>) or by none (<tt>NOT
! 3893: Referred</tt>).</p>
! 3894:
! 3895: <p>If the element or attribute to which the condition is attached is a
! 3896: reference, the condition can be based on the fact that it acts as the first
! 3897: reference to the designated element (<tt>FirstRef</tt>), or as the last
! 3898: (<tt>LastRef</tt>), or as a reference to an element located in another
! 3899: document (<tt>ExternalRef</tt>) or in the same document
! 3900: (<tt>InternalRef</tt>).</p>
1.1 cvs 3901:
1.30 ! cvs 3902: <p>The condition can also be based on the fact that the element is an <a
1.18 cvs 3903: href="#inclusion">inclusion</a>. This is noted (<tt>CopyRef</tt>).</p>
1.30 ! cvs 3904:
! 3905: <p>Like all conditions, conditions on references can be inverted by the
1.18 cvs 3906: <tt>NOT</tt> keyword. These conditions can be associated only with <a
3907: href="#sectc4232">creation rules</a>.</p>
3908: </div>
1.1 cvs 3909:
1.18 cvs 3910: <div class="subsubsection">
1.30 ! cvs 3911: <h4><a name="sectd42143">Conditions on logical attributes</a></h4>
! 3912:
! 3913: <p>The condition can be based on the presence or absence of attributes
! 3914: associated with the element, no matter what the attributes or their values.
! 3915: The <tt>AnyAttributes</tt> keyword expresses this condition.</p>
1.1 cvs 3916:
1.30 ! cvs 3917: <p>If the condition appears in the presentation rules of an attribute, the
1.18 cvs 3918: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
1.1 cvs 3919: the rules must only be applied if this attribute is the first attribute for
3920: the element or if it is the last (respectively). These conditions can also be
1.18 cvs 3921: inverted by the <tt>NOT</tt> keyword. These conditions can be associated only
3922: with <a href="#sectc4232">creation rules</a>.</p>
1.30 ! cvs 3923:
! 3924: <p>It is also possible to apply certain presentation rules only when the
! 3925: element being processed or one of its ancestors has a certain attribute,
! 3926: perhaps with a certain value. This can be done in the <a
1.18 cvs 3927: href="#sectc4210"><tt>ATTRIBUTES</tt> section</a>.</p>
3928: </div>
1.1 cvs 3929:
1.18 cvs 3930: <div class="subsubsection">
1.30 ! cvs 3931: <h4><a name="sectd42144">Conditions on page breaks</a></h4>
1.1 cvs 3932:
1.30 ! cvs 3933: <p>The page break base type (and only this type) can use the following
1.18 cvs 3934: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, and <tt>UserPage</tt>.
3935: The <tt>ComputedPage</tt> condition indicates that the presentation rule(s)
1.1 cvs 3936: should apply if the page break was created automatically by Thot; the
1.18 cvs 3937: <tt>StartPage</tt> condition is true if the page break is generated before the
3938: element by the <tt>Page</tt> rule; and the <tt>UserPage</tt> condition applies
3939: if the page break was inserted by the user.</p>
1.30 ! cvs 3940:
! 3941: <p>These conditions can be associated only with <a href="#sectc4232">creation
1.18 cvs 3942: rules</a>.</p>
3943: </div>
1.1 cvs 3944:
1.18 cvs 3945: <div class="subsubsection">
1.30 ! cvs 3946: <h4><a name="sectd42145">Conditions on the element's content</a></h4>
1.1 cvs 3947:
1.30 ! cvs 3948: <p>The condition can be based on whether or not the element is empty. An
! 3949: element which has no children or whose leaves are all empty is considered to
! 3950: be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
! 3951: optionally preceded by the <tt>NOT</tt> keyword. This condition can be
! 3952: associated only with <a href="#sectc4232">creation rules</a>.</p>
1.18 cvs 3953: </div>
1.1 cvs 3954:
1.18 cvs 3955: <div class="subsubsection">
1.30 ! cvs 3956: <h4><a name="sectd42146">Conditions on counters</a></h4>
1.1 cvs 3957:
1.30 ! cvs 3958: <p>Presentation rules can apply when the counter's value is one, is even or
! 3959: odd, is equal, greater than or less than a given value or falls in a range of
1.1 cvs 3960: values. This is particularly useful for creating header and footer boxes.
1.18 cvs 3961: These conditions can be associated only with <a href="#sectc4232">creation
3962: rules</a>.</p>
1.30 ! cvs 3963:
! 3964: <p>To compare the value of a counter to a given value, a comparison is given
1.1 cvs 3965: between parentheses. The comparison is composed of the counter name followed
3966: by an equals, greater than, or less than sign and the value to which the
3967: counter will be compared. A test for whether or not a counter's value falls
3968: in a range also appears within parentheses. In this case, the counter name is
1.18 cvs 3969: followed by the <tt>IN</tt> keyword and the range definition within brackets.
3970: The <tt>Even</tt>, <tt>Odd</tt> and <tt>One</tt> are used to test a counter's
3971: value and are followed by the counter name between parentheses.</p>
1.30 ! cvs 3972:
! 3973: <p>The list of possible conditions on counters is:</p>
1.18 cvs 3974: <dl>
1.30 ! cvs 3975: <dt><tt>Even (Counter)</tt></dt>
! 3976: <dd>the box is created only if the counter has an even value.</dd>
! 3977: <dt><tt>Odd (Counter)</tt></dt>
! 3978: <dd>the box is created only if the counter has an odd value.</dd>
! 3979: <dt><tt>One (Counter)</tt></dt>
! 3980: <dd>the box is created only the counter's value is 1.</dd>
! 3981: <dt><tt>NOT One (Counter)</tt></dt>
! 3982: <dd>the box is created, unless the counter's value is 1.</dd>
! 3983: <dt><tt>(Counter < Value)</tt></dt>
! 3984: <dd>the box is created only if the counter's value is less than
! 3985: Value.</dd>
! 3986: <dt><tt>(Counter > Value)</tt></dt>
! 3987: <dd>the box is created only if the counter's value is greater than
! 3988: Value.</dd>
! 3989: <dt><tt>(Counter = Value)</tt></dt>
! 3990: <dd>the box is created only if the counter's value is equal to Value.</dd>
! 3991: <dt><tt>NOT (Counter = Value)</tt></dt>
! 3992: <dd>the is created only if the counter's value is different than
! 3993: Value.</dd>
! 3994: <dt><tt>(Counter IN [MinValue..MaxValue])</tt></dt>
! 3995: <dd>the box is created only if the counter's value falls in the range
! 3996: bounded by MinValue and MaxValue (inclusive).</dd>
! 3997: <dt><tt>NOT (Counter IN [MinValue..MaxValue])</tt></dt>
! 3998: <dd>the box is created only if the value of the counter does not fall in
! 3999: the range bounded by MinValue and MaxValue (inclusive).</dd>
1.18 cvs 4000: </dl>
1.30 ! cvs 4001:
! 4002: <p><strong>Note:</strong> the <tt>NOT Even</tt> and <tt>NOT Odd</tt>
! 4003: conditions are syntactically correct but can be expressed more simply by
! 4004: <tt>Odd</tt> and <tt>Even</tt>, respectively.</p>
1.18 cvs 4005: </div>
4006: </div>
1.1 cvs 4007:
1.18 cvs 4008: <div class="subsection">
1.30 ! cvs 4009: <h3><a name="sectc4215">A presentation rule</a></h3>
1.1 cvs 4010:
1.30 ! cvs 4011: <p>A presentation rule defines either a presentation parameter or presentation
1.18 cvs 4012: function. The parameters are:</p>
4013: <ul>
1.30 ! cvs 4014: <li>the position of the vertical and horizontal reference axes of the
! 4015: box,</li>
! 4016: <li>the position of the box in relation to other boxes,</li>
! 4017: <li>the height or width of the box, with overflow exceptions,</li>
! 4018: <li>the margins, padding and borders of the box,</li>
! 4019: <li>the characteristics of the lines contained in the box: linespacing,
! 4020: indentation of the first line, justification, hyphenation,</li>
! 4021: <li>the conditions for breaking the box across pages,</li>
! 4022: <li>the characteristics of the characters contained in the box: size, font,
! 4023: style, underlining,</li>
! 4024: <li>the depth of the box among overlapping boxes (often called stacking
! 4025: order),</li>
! 4026: <li>the characteristics of graphic elements contained in the box: style and
! 4027: thickness of lines, fill pattern for closed objects,</li>
! 4028: <li>the colors in text, graphics, pictures, and symbols contained in the box
! 4029: are displayed or printed,</li>
! 4030: <li>for presentation boxes only, the contents of the box.</li>
! 4031: </ul>
! 4032:
! 4033: <p>The <a name="presfunct">presentation functions</a> are:</p>
! 4034: <ul>
! 4035: <li>the creation of a presentation box</li>
! 4036: <li>the line-breaking or page-breaking style,</li>
! 4037: <li>the copying of another box,</li>
! 4038: <li>the display of the box background and border,</li>
! 4039: <li>the display of a background picture and its aspect.</li>
! 4040: </ul>
! 4041:
! 4042: <p>For each box and each view, every presentation parameter is defined once
! 4043: and only once, either explicitly or by the <a href="#sectc427">default
! 4044: rules</a>. In contrast, presentation functions are not obligatory and can
! 4045: appear many times for the same element. for example an element can create
! 4046: many presentation boxes. Another element may not use any presentation
1.18 cvs 4047: functions.</p>
1.30 ! cvs 4048:
! 4049: <p>Each rule defining a presentation parameter begins with a keyword followed
! 4050: by a colon. The keyword indicates the parameter which is the subject of the
1.18 cvs 4051: rule. After the keyword and the colon, the remainder of the rule varies. All
4052: rules are terminated by a semicolon.</p>
4053: <pre> Rule = PresParam ';' / PresFunc ';' .
1.6 cvs 4054: PresParam ='VertRef' ':' PositionHoriz /
4055: 'HorizRef' ':' PositionVert /
4056: 'VertPos' ':' VPos /
4057: 'HorizPos' ':' HPos /
4058: 'Height' ':' Dimension /
4059: 'Width' ':' Dimension /
4060: 'VertOverflow' ':' Boolean /
1.1 cvs 4061: 'HorizOverflow' ':' Boolean /
1.26 cvs 4062: 'MarginTop' ':' MarginWidth /
4063: 'MarginRight' ':' MarginWidth /
4064: 'MarginBottom' ':' MarginWidth /
4065: 'MarginLeft' ':' MarginWidth /
4066: 'PaddingTop' ':' PaddingWidth /
4067: 'PaddingRight' ':' PaddingWidth /
4068: 'PaddingBottom' ':' PaddingWidth /
4069: 'PaddingLeft' ':' PaddingWidth /
4070: 'BorderTopWidth' ':' BorderWidth /
4071: 'BorderRightWidth' ':' BorderWidth /
4072: 'BorderBottomWidth' ':' BorderWidth /
4073: 'BorderLeftWidth' ':' BorderWidth /
4074: 'BorderTopColor' ':' BorderColor /
4075: 'BorderRightColor' ':' BorderColor /
4076: 'BorderBottomColor' ':' BorderColor /
4077: 'BorderLeftColor' ':' BorderColor /
4078: 'BorderTopStyle' ':' BorderStyle /
4079: 'BorderRightStyle' ':' BorderStyle /
4080: 'BorderBottomStyle' ':' BorderStyle /
4081: 'BorderLeftStyle' ':' BorderStyle .
1.6 cvs 4082: 'LineSpacing' ':' DistanceInherit /
4083: 'Indent' ':' DistanceInherit /
4084: 'Adjust' ':' AdjustInherit /
4085: 'Justify' ':' BoolInherit /
4086: 'Hyphenate' ':' BoolInherit /
4087: 'PageBreak' ':' Boolean /
4088: 'LineBreak' ':' Boolean /
4089: 'InLine' ':' Boolean /
4090: 'NoBreak1' ':' AbsDist /
4091: 'NoBreak2' ':' AbsDist /
4092: 'Gather' ':' Boolean /
4093: 'Visibility' ':' NumberInherit /
4094: 'Size' ':' SizeInherit /
4095: 'Font' ':' NameInherit /
4096: 'Style' ':' StyleInherit /
1.23 cvs 4097: 'Weight' ':' WeightInherit /
1.6 cvs 4098: 'Underline' ':' UnderLineInherit /
4099: 'Thickness' ':' ThicknessInherit /
4100: 'Depth' ':' NumberInherit /
4101: 'LineStyle' ':' LineStyleInherit /
4102: 'LineWeight' ':' DistanceInherit /
4103: 'FillPattern' ':' NameInherit /
4104: 'Background' ':' NameInherit /
1.13 cvs 4105: 'Foreground' ':' NameInherit /
1.6 cvs 4106: 'Content' ':' VarConst .
1.1 cvs 4107: PresFunc = Creation '(' BoxID ')' /
4108: 'Line' /
4109: 'NoLine' /
4110: 'Page' '(' BoxID ')' /
1.13 cvs 4111: 'Copy' '(' BoxTypeToCopy ')' /
4112: 'ShowBox' /
1.18 cvs 4113: 'BackgroundPicture' ':' FileName /
4114: 'PictureMode' ':' PictMode /</pre>
4115: </div>
4116:
4117: <div class="subsection">
1.30 ! cvs 4118: <h3><a name="sectc4216">Box axes</a></h3>
1.18 cvs 4119:
1.30 ! cvs 4120: <p>The position of the middle axes <tt>VMiddle</tt> and <tt>HMiddle</tt> in
1.1 cvs 4121: relation to their box is always calculated automatically as a function of the
4122: height and width of the box and is not specified by the presentation rules. In
4123: the presentation schema, these middle axes are used only to position their box
4124: with respect to another by specifying the distance between the middle axis and
1.18 cvs 4125: an axis or a side of another box (see the <a href="#sectc4218">relative
4126: position</a>).</p>
1.30 ! cvs 4127:
! 4128: <p>The reference axes of a box are also used to position their box in relation
! 4129: to another, but in contrast to the middle axes, the presentation schema must
! 4130: make their position explicit, either in relation to a side or the middle axis
! 4131: of the box itself, or in relation to an axis of an enclosed box.</p>
! 4132:
! 4133: <p>Only boxes of base elements have predefined reference axes. For character
1.1 cvs 4134: string boxes, the horizontal reference axis is the baseline of the characters
4135: (the line which passes immediately under the upper-case letters, ignoring the
4136: letter Q) and the vertical reference axis is at the left edge of the first
1.18 cvs 4137: character of the string.</p>
1.30 ! cvs 4138:
! 4139: <p>The positions of a box's reference axes are defined by the <tt>VertRef</tt>
1.18 cvs 4140: and <tt>HorizRef</tt> rules which specify the <a href="#distance">distance</a>
1.1 cvs 4141: between the reference axis and an axis or parallel side of the same box or of
1.18 cvs 4142: an enclosed box.</p>
4143: <pre> 'VertRef' ':' PositionHoriz
4144: 'HorizRef' ':' PositionVert</pre>
1.30 ! cvs 4145:
1.18 cvs 4146: <blockquote class="example">
1.30 ! cvs 4147: <p><strong>Example:</strong></p>
! 4148:
! 4149: <p>If, in the structure schema for mathematical formulas, the fraction
! 4150: element is defined by</p>
! 4151: <pre>Fraction = BEGIN
1.1 cvs 4152: Numerator = Expression;
4153: Denominator = Expression;
1.18 cvs 4154: END;</pre>
1.30 ! cvs 4155:
! 4156: <p>then the horizontal reference axis of the fraction can be positioned on
! 4157: top of the denominator by the rule:</p>
! 4158: <pre>Fraction :
1.1 cvs 4159: BEGIN
4160: HorizRef : Enclosed Denominator . Top;
4161: ...
1.18 cvs 4162: END;</pre>
1.30 ! cvs 4163:
! 4164: <p>To put the horizontal reference axis of a column at its middle:</p>
! 4165: <pre>Column :
1.1 cvs 4166: BEGIN
4167: HorizRef : * . HMiddle;
4168: ...
1.18 cvs 4169: END;</pre>
4170: </blockquote>
4171: </div>
1.1 cvs 4172:
1.18 cvs 4173: <div class="subsection">
1.30 ! cvs 4174: <h3><a name="sectc4217">Distance units</a></h3>
1.1 cvs 4175:
1.30 ! cvs 4176: <p>Some distances and dimensions appear in many rules of a presentation
! 4177: schema, especially in position rules (<tt>VertPos, HorizPos</tt>), in extent
! 4178: rules for boxes (<tt>Height, Width</tt>), in rules defining lines
! 4179: (<tt>LineSpacing, Indent</tt>), in rules controlling pagination (<tt>NoBreak1,
! 4180: NoBreak2</tt>) and in rules specifying the thickness of strokes
! 4181: (<tt>LineWeight</tt>).</p>
! 4182:
! 4183: <p>In all these rules, the distance or extent can be expressed</p>
! 4184: <ul>
! 4185: <li>either in relative units, which depend on the size of the characters in
! 4186: the current font: height of the element's font or height of the letter
! 4187: 'x',</li>
! 4188: <li>or in absolute units: centimeter, millimeter, inch, typographer's point,
! 4189: pica or pixel.</li>
! 4190: </ul>
! 4191:
! 4192: <p>Units can be chosen freely. Thus, it is possible to use relative units in
! 4193: one rule, centimeters in the next rule, and typographer's points in
! 4194: another.</p>
! 4195:
! 4196: <p>Absolute units are used to set rigid rules for the appearance of documents.
! 4197: In contrast, relative units allow changes of scale. The editor lets the value
! 4198: of relative units be changed dynamically. Such changes affect every box using
1.1 cvs 4199: relative units simultaneously and in the same proportion. Changing the value
4200: of the relative units affects the size of the characters and graphical
1.18 cvs 4201: elements, and the size of the boxes and the distances between them.</p>
1.30 ! cvs 4202:
! 4203: <p>A <a name="distance">distance</a> or extent is specified by a number, which
1.1 cvs 4204: may be followed by one or more spaces and a units keyword. When there is no
4205: units keyword, the number specifies the number of relative units, where a
4206: relative unit is the height of a character in the current font (an em). When
4207: the number is followed by a units keyword, the keyword indicates the type of
1.18 cvs 4208: absolute units:</p>
4209: <ul>
1.30 ! cvs 4210: <li><tt>em</tt>: height of the element's font,</li>
! 4211: <li><tt>ex</tt>: height of the letter 'x',</li>
! 4212: <li><tt>cm</tt>: centimeter,</li>
! 4213: <li><tt>mm</tt>: millimeter,</li>
! 4214: <li><tt>in</tt>: inch (1 in = 2.54 cm),</li>
! 4215: <li><tt>pt</tt>: point (1 pt = 1/72 in),</li>
! 4216: <li><tt>pc</tt>: pica (1 pc = 12 pt),</li>
! 4217: <li><tt>px</tt>: pixel.</li>
1.18 cvs 4218: </ul>
1.30 ! cvs 4219:
! 4220: <p>Whatever the chosen unit, relative or absolute, the number is not
! 4221: necessarily an integer and may be expressed in fixed point notation (using the
! 4222: American convention of a period to express the decimal point).</p>
! 4223:
! 4224: <p>If the distance appears in a presentation rule for a numeric attribute, the
1.1 cvs 4225: number can be replaced by the name of an attribute. In this case, the value
4226: of the attribute is used. Obviously, the attribute name cannot be followed by
4227: a decimal point and a fractional part, but it can be followed a units keyword.
1.18 cvs 4228: However, the choice of units is limited to em, ex, pt and px.</p>
4229: <pre> Distance = [ Sign ] AbsDist .
1.1 cvs 4230: Sign ='+' / '-' .
4231: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
4232: [ Unit ].
4233: IntegerOrAttr = IntegerPart / AttrID .
4234: IntegerPart = NUMBER .
4235: DecimalPart = NUMBER .
4236: Unit ='em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
1.18 cvs 4237: 'pc' / 'px' / '%' .</pre>
1.30 ! cvs 4238:
1.18 cvs 4239: <blockquote class="example">
1.30 ! cvs 4240: <p><strong>Example:</strong></p>
! 4241:
! 4242: <p>The following rules specify that a box has a height of 10.5 centimeters
! 4243: and a width of 5.3 ems:</p>
! 4244: <pre>Height : 10.5 cm;
1.18 cvs 4245: Width : 5.3;</pre>
4246: </blockquote>
4247: </div>
1.1 cvs 4248:
1.18 cvs 4249: <div class="subsection">
1.30 ! cvs 4250: <h3><a name="sectc4218">Relative positions</a></h3>
1.1 cvs 4251:
1.30 ! cvs 4252: <p>The positioning of boxes uses the eight axes and sides, the sides generally
1.1 cvs 4253: being used to define the juxtapositioning (vertical or horizontal) of boxes,
4254: the middle axes being used to define centering, and the reference axes being
1.18 cvs 4255: used for alignment.</p>
1.30 ! cvs 4256:
! 4257: <p>Two rules allow a box to be placed relative to other boxes. The
1.18 cvs 4258: <tt>VertPos</tt> rule positions the box vertically. The <tt>HorizPos</tt>
4259: rule positions the box horizontally. It is possible that a box's position
4260: could be entirely determined by other boxes positioned relative to it. In this
4261: case, the position is implicit and the word <tt>nil</tt> can be used to
4262: specify that no position rule is needed. Otherwise, an explicit rule must be
4263: given by indicating the axis or side which defines the position of the box,
4264: followed by an equals sign and the distance between between this axis or side
4265: and a parallel axis or side of another box, called the reference box. The box
4266: for which the rule is written will be positioned relative to the reference
4267: box.</p>
4268: <pre> 'VertPos' ':' VPos
1.6 cvs 4269: 'HorizPos' ':' HPos
4270: HPos = 'nil' / VertAxis '=' HorizPosition
4271: [ 'UserSpecified' ].
4272: VPos = 'nil' / HorizAxis '=' VertPosition
4273: [ 'UserSpecified' ].
1.1 cvs 4274: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
1.18 cvs 4275: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .</pre>
1.30 ! cvs 4276:
! 4277: <p>The reference box is an adjacent box: enclosing, enclosed or adjacent. When
! 4278: a rule is associated with a reference type attribute (and only in this case),
! 4279: it can be a box of the element designated by the attribute. The reference box
1.18 cvs 4280: can be either a presentation box previously defined in the <tt>BOXES</tt>
1.1 cvs 4281: section of the schema and created by a creation function, or the box
1.18 cvs 4282: associated with a structured element.</p>
1.30 ! cvs 4283:
! 4284: <p>The structural position of the reference box (relative to the box for which
1.18 cvs 4285: the rule is being written) is indicated by a keyword: <tt>Enclosing</tt>,
4286: <tt>Enclosed</tt>, or, for sibling boxes, <tt>Previous</tt> or <tt>Next</tt>.
1.1 cvs 4287: The reference attributes, or presentation boxes created by a reference
1.18 cvs 4288: attribute, the <tt>Referred</tt> keyword may be used to designate the element
4289: which the reference points to. The keyword <tt>Creator</tt> can be used in
1.1 cvs 4290: rules for presentation boxes to designate the box of the element which created
1.18 cvs 4291: the presentation box. Finally, the <tt>Root</tt> keyword can be used to
4292: designate the root of the document.</p>
1.30 ! cvs 4293:
! 4294: <p>When the keyword is ambiguous, it is followed by the name of an element
! 4295: type or presentation box which resolves the ambiguity (the <tt>Creator</tt>
! 4296: and <tt>Root</tt> keywords are never ambiguous). If this name is not given,
! 4297: then the first box encountered is used as the reference box. It is also
! 4298: possible to use just the name of an element type or presentation box without
! 4299: an initial keyword. In this case, a sibling having that name will be used. If
! 4300: the name is preceded by the keyword <tt>NOT</tt>, then the reference box will
! 4301: be the first box whose type is not the named one.</p>
! 4302:
! 4303: <p>In place of the box or type name, the keywords <tt>AnyElem</tt>,
1.18 cvs 4304: <tt>AnyBox</tt> and <tt>ElemWithAttr</tt> can be used, representing
1.17 cvs 4305: respectively, any structured element box, any presentation box, and the box
4306: corresponding to any structured element having a particular attribute,
4307: whatever its value; the name of this attribute must follow the keyword
1.18 cvs 4308: <tt>ElemWithAttr</tt>.</p>
1.30 ! cvs 4309:
! 4310: <p>A type name may be preceded by a star in order to resolve the ambiguity in
! 4311: the special case where the structure schema defines an <a
1.18 cvs 4312: href="#sectd3284">inclusion</a> without expansion (or with partial expansion)
4313: of the same type as an element of the scheme. For mark pairs (and only for <a
4314: href="#sectd3285">mark pairs</a>) the type name <em>must</em> be preceded by
4315: the <tt>First</tt> or <tt>Second</tt> keyword, which indicates which of the
4316: two marks of the pair should be used as the reference box.</p>
1.30 ! cvs 4317:
! 4318: <p>The star character ('<tt>*</tt>') used alone designates the box to which
! 4319: the rule applies (in this case, it is obviously useless to specify the type of
! 4320: the reference box).</p>
! 4321:
! 4322: <p>The keywords <tt>Enclosing</tt> and <tt>Enclosed</tt> can be used no matter
1.1 cvs 4323: what constructor defines the type to which the rule applies. When applied to
1.18 cvs 4324: the element which represents the entire document, <tt>Enclosing</tt>
1.1 cvs 4325: designates the window or page in which the document's image is displayed for
4326: the view to which the rule applies. A box or type name without a keyword is
4327: used for aggregate elements and designates another element of the same
4328: aggregate. It can also be used to designate a presentation or page layout
1.18 cvs 4329: box. The keywords <tt>Previous</tt> and <tt>Next</tt> are primarily used to
1.1 cvs 4330: denote list elements, but can also be used to denote elements of an
1.18 cvs 4331: aggregate.</p>
1.30 ! cvs 4332:
! 4333: <p>In the position rule, the structural position relative to the reference box
! 4334: is followed, after a period, by the name of an axis or side. The rule
! 4335: specifies its node's position as being some distance from this axis or side of
! 4336: the reference box. If this distance is zero, then the distance does not
! 4337: appear in the rule. Otherwise, it does appear as a positive or negative
! 4338: number (the sign is required for negative numbers). The sign takes into
! 4339: account the orientation of the coordinate axes: for top to bottom for the
! 4340: vertical axis and from left to right for the horizontal axis. Thus, a
! 4341: negative distance in a vertical position indicates that the side or axis
! 4342: specified in the rule is above the side or axis of the reference box.</p>
! 4343:
! 4344: <p>The distance can be followed by the <tt>UserSpecified</tt> keyword (even if
1.18 cvs 4345: the distance is nil and does not appear, the <tt>UserSpecified</tt> keyword
1.1 cvs 4346: can be used). It indicates that when the element to which the rule applies is
4347: being created, the editor will ask the user to specify the distance himself,
4348: using the mouse. In this case, the distance specified in the rule is a
4349: default distance which is suggested to the user but can be modified. The
1.18 cvs 4350: <tt>UserSpecified</tt> keyword can be used either in the vertical position
4351: rule, the horizontal position rule, or both.</p>
4352: <pre> VertPosition = Reference '.' HorizAxis [ Distance ] .
1.1 cvs 4353: HorizPosition = Reference '.' VertAxis [ Distance ] .
4354: Reference ='Enclosing' [ BoxTypeNot ] /
4355: 'Enclosed' [ BoxTypeNot ] /
4356: 'Previous' [ BoxTypeNot ] /
4357: 'Next' [ BoxTypeNot ] /
4358: 'Referred' [ BoxTypeNot ] /
4359: 'Creator' /
4360: 'Root' /
4361: '*' /
4362: BoxOrType .
4363: BoxOrType = BoxID /
4364: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 4365: 'AnyElem' / 'AnyBox' /
4366: 'ElemWithAttr' AttrID .
1.18 cvs 4367: BoxTypeNot = [ 'NOT' ] BoxOrType .</pre>
1.30 ! cvs 4368:
1.18 cvs 4369: <blockquote class="example">
1.30 ! cvs 4370: <p><strong>Example:</strong></p>
! 4371:
! 4372: <p>If a <a name="expos1">report</a> is defined by the following structure
! 4373: schema:</p>
! 4374: <pre>Report = BEGIN
1.6 cvs 4375: Title = Text;
4376: Summary = Text;
4377: Keywords = Text;
4378: ...
1.18 cvs 4379: END;</pre>
1.30 ! cvs 4380:
! 4381: <p>then the presentation schema could contain the rules:</p>
! 4382: <pre>Report : BEGIN
1.6 cvs 4383: VertPos : Top = Enclosing . Top;
4384: HorizPos : Left = Enclosing . Left;
4385: ...
1.18 cvs 4386: END;</pre>
1.30 ! cvs 4387:
! 4388: <p>These rules place the <a name="reportexample">report</a> in the upper
! 4389: left corner of the enclosing box, which is the window in which the document
! 4390: is being edited.</p>
! 4391: <pre>Title : BEGIN
1.6 cvs 4392: VertPos : Top = Enclosing . Top + 1;
4393: HorizPos : VMiddle = Enclosing . VMiddle;
4394: ...
1.18 cvs 4395: END;</pre>
1.30 ! cvs 4396:
! 4397: <p>The top of the title is one line (a line has the height of the characters
! 4398: of the title) from the top of the report, which is also the top of the
! 4399: editing window. The title is centered horizontally in the window (see <a
! 4400: href="#posdim">figure</a>).</p>
! 4401: <pre>Summary : BEGIN
1.1 cvs 4402: VertPos : Top = Title . Bottom + 1.5;
4403: HorizPos : Left = Enclosing . Left + 2 cm;
4404: ...
1.18 cvs 4405: END;</pre>
1.30 ! cvs 4406:
! 4407: <p>The top of the summary is place a line and a half below the bottom of the
! 4408: title and is shifted two centimeters from the side of the window.</p>
1.18 cvs 4409: </blockquote>
1.30 ! cvs 4410:
1.18 cvs 4411: <blockquote class="example">
1.30 ! cvs 4412: <p><strong>Example:</strong></p>
! 4413:
! 4414: <p>Suppose there is a <a name="expos2">Design</a> logical structure which
! 4415: contains graphical elements:</p>
! 4416: <pre>Design = LIST OF (ElemGraph = GRAPHICS);</pre>
! 4417:
! 4418: <p>The following rules allow the user to freely choose the position of each
! 4419: element when it is created:</p>
! 4420: <pre>ElemGraph =
1.1 cvs 4421: BEGIN
4422: VertPos : Top = Enclosing . Top + 1 cm UserSpecified;
4423: HorizPos: Left = Enclosing . Left UserSpecified;
4424: ...
1.18 cvs 4425: END;</pre>
1.30 ! cvs 4426:
! 4427: <p>Thus, when a graphical element is created, its default placement is at
! 4428: the left of the window and 1 cm from the top, but the user can move it
! 4429: immediately, simply by moving the mouse.</p>
1.18 cvs 4430: </blockquote>
4431: </div>
1.1 cvs 4432:
1.18 cvs 4433: <div class="subsection">
1.30 ! cvs 4434: <h3><a name="sectc4219">Box extents</a></h3>
1.1 cvs 4435:
1.30 ! cvs 4436: <p>The extents (height and width) of each box are defined by the two rules
1.18 cvs 4437: <tt>Height</tt> and <tt>Width</tt>. There are three types of extents: fixed,
4438: relative, and elastic.</p>
1.1 cvs 4439:
1.18 cvs 4440: <div class="subsubsection">
1.30 ! cvs 4441: <h4><a name="sectd42191">Fixed extents</a></h4>
1.1 cvs 4442:
1.30 ! cvs 4443: <p>A fixed dimension sets the height or width of the box independently of all
1.18 cvs 4444: other boxes. It is expressed in <a href="#sectc4217">distance units</a>. The
4445: extent can be followed by the <tt>UserSpecified</tt> keyword which indicates
1.1 cvs 4446: that when the element to which the rule applies is being created, the editor
4447: will ask the user to specify the extent himself, using the mouse. In this
4448: case, the extent specified in the rule is a default extent which is suggested
1.18 cvs 4449: to the user but can be modified. The <tt>UserSpecified</tt> keyword can be
4450: used either in the <tt>Height</tt> rule, the <tt>Width</tt> rule, or both.</p>
1.30 ! cvs 4451:
! 4452: <p>A fixed extent rule can be ended by the <tt>Min</tt> keyword, which
! 4453: signifies that the indicated value is a minimum, and that, if the contents of
! 4454: the box require it, a larger extent is possible.</p>
1.18 cvs 4455: <pre> 'Height' ':' Dimension
1.1 cvs 4456: 'Width' ':' Dimension
4457: Dimension = AbsDist [ 'UserSpecified' ] [ 'Min' ] /
1.18 cvs 4458: ...</pre>
1.30 ! cvs 4459:
1.18 cvs 4460: <blockquote class="example">
1.30 ! cvs 4461: <p><strong>Example:</strong></p>
! 4462:
! 4463: <p>Continuing with the <a href="#expos2">previous example</a>, it is
! 4464: possible to allow the user to choose the size of each graphical element as
! 4465: it is created:</p>
! 4466: <pre>ElemGraph : BEGIN
1.6 cvs 4467: Width : 2 cm UserSpecified;
1.1 cvs 4468: Height : 1 cm UserSpecified;
4469: ...
1.18 cvs 4470: END;</pre>
1.30 ! cvs 4471:
! 4472: <p>Thus, when a graphical element is create, it is drawn by default with a
! 4473: width of 2 cm and a height of 1 cm, but the user is free to resize it
! 4474: immediately with the mouse.</p>
! 4475: <pre>Summary : BEGIN
1.1 cvs 4476: Height : 5 cm Min;
4477: ...
4478: END;
4479: Keywords : BEGIN
4480: VertPos : Top = Summary . Bottom;
4481: ...
1.18 cvs 4482: END;</pre>
4483: </blockquote>
4484: </div>
1.1 cvs 4485:
1.18 cvs 4486: <div class="subsubsection">
1.30 ! cvs 4487: <h4><a name="sectd42192">Relative extents</a></h4>
! 4488:
! 4489: <p>A relative extent determines the extent as a function of the extent of
! 4490: another box, just as a relative position places a box in relation to another.
! 4491: The reference box in an extent rule is designated using the same syntax as is
! 4492: used in a relative position rule. It is followed by a period and a
! 4493: <tt>Height</tt> or <tt>Width</tt> keyword, depending on the extent being
! 4494: referred to. Next comes the relation between the extent being defined and the
! 4495: extent of the reference box. This relation can be either a percentage or a
! 4496: difference.</p>
1.1 cvs 4497:
1.30 ! cvs 4498: <p>A percentage is indicated by a star (the multiplication symbol) followed by
1.1 cvs 4499: the numeric percentage value (which may be greater than or less than 100) and
4500: the percent (`%') character. A difference is simply indicated by a signed
1.18 cvs 4501: difference.</p>
1.30 ! cvs 4502:
! 4503: <p>If the rule appears in the presentation rules of a numeric attribute, the
1.1 cvs 4504: percentage value can be replaced by the name of the attribute. This attribute
1.18 cvs 4505: is then used as a percentage. The attribute can also be used as part of a <a
4506: href="#distance">difference</a>.</p>
1.30 ! cvs 4507:
! 4508: <p>Just as with a fixed extent, a relative extent rule can end with the
1.18 cvs 4509: <tt>Min</tt> keyword, which signifies that the extent is a minimum and that,
4510: if the contents of the box require it, a larger extent is possible.</p>
1.30 ! cvs 4511:
! 4512: <p>A special case of relative extent rules is:</p>
1.18 cvs 4513: <pre>Height : Enclosed . Height;</pre>
1.30 ! cvs 4514:
! 4515: <p>or</p>
1.18 cvs 4516: <pre>Width : Enclosed . Width;</pre>
1.30 ! cvs 4517:
! 4518: <p>which specifies that the box has a height (or width) such that it encloses
! 4519: all the boxes which it contains, excluding boxes having a rule
! 4520: <tt>VertOverflow: Yes;</tt> or <tt>HorizOverflow: Yes;</tt>.</p>
! 4521:
! 4522: <p><strong>Note:</strong> character strings (type <tt>TEXT_UNIT</tt>)
! 4523: generally must use the sum of the widths of the characters which compose them
! 4524: as their width, which is expressed by the rule:</p>
1.18 cvs 4525: <pre>TEXT_UNIT :
4526: Width : Enclosed . Width;</pre>
1.30 ! cvs 4527:
! 4528: <p>If this rule is not the default <tt>Width</tt> rule, it must be given
1.18 cvs 4529: explicitly in the <tt>RULES</tt> section which defines the presentation rules
4530: of the logical elements.</p>
4531: <pre> 'Height' ':' Extent
1.1 cvs 4532: 'Width' ':' Extent
4533: Extent = Reference '.' HeightWidth [ Relation ]
4534: [ 'Min' ] / ...
4535: HeightWidth ='Height' / 'Width' .
4536: Relation ='*' ExtentAttr '%' / Distance .
4537: ExtentAttr = ExtentVal / AttrID .
1.18 cvs 4538: ExtentVal = NUMBER .</pre>
1.30 ! cvs 4539:
1.18 cvs 4540: <blockquote class="example">
1.30 ! cvs 4541: <p><strong>Example:</strong></p>
! 4542:
! 4543: <p>Completing the <a href="#expos1">above example</a>, it is possible to
! 4544: specify that the report takes its width from the editing window and its
! 4545: height from the size of its contents (this can obviously be greater than
! 4546: that of the window):</p>
! 4547: <pre>Report : BEGIN
1.1 cvs 4548: Width : Enclosing . Width;
4549: Height : Enclosed . Height;
4550: ...
1.18 cvs 4551: END;</pre>
1.30 ! cvs 4552:
! 4553: <p>Then, the following rules make the title occupy 60% of the width of the
! 4554: report (which is that of the window) and is broken into centered lines of
! 4555: this width (see the <a href="#sectc4222"><tt>Line</tt> rule</a>).</p>
! 4556: <pre>Title : BEGIN
1.1 cvs 4557: Width : Enclosing . Width * 60%;
4558: Height : Enclosed . Height;
4559: Line;
4560: Adjust : VMiddle;
4561: ...
1.18 cvs 4562: END;</pre>
1.30 ! cvs 4563:
! 4564: <p>The summary occupy the entire width of the window, with the exception of
! 4565: a 2 cm margin reserved by the horizontal position rule:</p>
! 4566: <pre>Summary : BEGIN
1.1 cvs 4567: Width : Enclosing . Width - 2 cm;
4568: Height : Enclosed . Height;
4569: ...
1.18 cvs 4570: END;</pre>
4571:
1.30 ! cvs 4572: <p>This set of rules, plus the <a href="#reportexample">position rules given
! 4573: above</a>, produce the layout of boxes shown in the following<a
! 4574: href="#posdim">figure</a>.</p>
! 4575:
! 4576: <div class="figure">
! 4577: <hr>
! 4578: <pre>-------------------------------------------------------------
1.1 cvs 4579: | Window and Report ^ |
4580: | | 1 line |
4581: | v |
4582: | ------------------------------------- |
4583: | | | |
4584: : 20% : Title : 20% :
1.30 ! cvs 4585: :<--------->: :<--------->:
1.1 cvs 4586: : : 60% : :
1.30 ! cvs 4587: : :<--------------------------------->: :
1.1 cvs 4588: | | | |
4589: | ------------------------------------- |
4590: | ^ |
4591: | | 1.5 line |
4592: | | |
4593: | v |
4594: | ---------------------------------------------------|
4595: | 2 cm | |
1.30 ! cvs 4596: |<------>| Summary |
1.18 cvs 4597: : : :</pre>
1.19 cvs 4598:
1.30 ! cvs 4599: <p align="center"><em><a name="posdim">Box position and
! 4600: extent</a><em></em></em></p>
! 4601: <hr>
! 4602: </div>
1.18 cvs 4603: </blockquote>
4604: </div>
1.1 cvs 4605:
1.18 cvs 4606: <div class="subsubsection">
1.30 ! cvs 4607: <h4><a name="sectd42193">Elastic extents</a></h4>
1.1 cvs 4608:
1.30 ! cvs 4609: <p>The last type of extent is the elastic extent. Either one or both extents
! 4610: can be elastic. A box has an elastic extent when two opposite sides are
! 4611: linked by distance constraints to two sides or axes of other boxes.</p>
! 4612:
! 4613: <p>One of the sides of the elastic box is linked by a position rule
1.18 cvs 4614: (<tt>VertPos</tt> or <tt>HorizPos</tt>) to a neighboring box. The other side
4615: is link to another box by a <tt>Height</tt> or <tt>Width</tt> rule, which
1.1 cvs 4616: takes the same form as the position rule. For the elastic box itself, the
4617: notions of sides (left or right, top or bottom) are fuzzy, since the movement
4618: of either one of the two reference boxes can, for example, make the left side
4619: of the elastic box move to the right of its right side. This is not
4620: important. The only requirement is that the two sides of the elastic box used
1.18 cvs 4621: in the position and extent rule are opposite sides of the box.</p>
4622: <pre> 'Height' ':' Extent
1.6 cvs 4623: 'Width' ':' Extent
1.18 cvs 4624: Extent = HPos / VPos / ...</pre>
1.30 ! cvs 4625:
1.18 cvs 4626: <blockquote class="example">
1.30 ! cvs 4627: <p><strong>Example:</strong></p>
! 4628:
! 4629: <p>Suppose we want to draw an elastic arrow or line between the middle of
! 4630: the bottom side of box A and the upper left corner of box B. To do this, we
! 4631: would define a graphics box whose upper left corner coincides with the
! 4632: middle of the bottom side of A (a position rule) and whose lower right
! 4633: corner coincides with with the upper left corner of B (dimension rules):</p>
! 4634: <pre>LinkedBox :
1.1 cvs 4635: BEGIN
1.6 cvs 4636: VertPos : Top = A .Bottom;
1.1 cvs 4637: HorizPos : Left = A . VMiddle;
1.6 cvs 4638: Height : Bottom = B . Top;
4639: Width : Right = B . Left;
1.18 cvs 4640: END;</pre>
4641: </blockquote>
1.30 ! cvs 4642:
1.18 cvs 4643: <blockquote class="example">
1.30 ! cvs 4644: <p><strong>Example:</strong></p>
! 4645:
! 4646: <p>The element SectionTitle creates a presentation box called SectionNum
! 4647: which contains the number of the section. Suppose we want to align the
! 4648: SectionNum and SectionTitle horizontally, have the SectionNum take its width
! 4649: from its contents (the section number), have the SectionTitle box begin 0.5
! 4650: cm to the right of the SectionNum box and end at the right edge of its
! 4651: enclosing box. This would make the SectionTitle box elastic, since its width
! 4652: is defined by the position of its left and right sides. The following rules
! 4653: produce this effect:</p>
! 4654: <pre>SectionNum :
1.1 cvs 4655: BEGIN
4656: HorizPos : Left = Enclosing . Left;
4657: Width : Enclosed . Width;
4658: ...
4659: END;
4660:
4661: SectionTitle :
4662: BEGIN
4663: HorizPos : Left = SectionNum . Right + 0.5 cm;
4664: Width : Right = Enclosing . Right;
4665: ...
1.18 cvs 4666: END;</pre>
4667: </blockquote>
4668: </div>
4669: </div>
1.1 cvs 4670:
1.18 cvs 4671: <div class="subsection">
1.30 ! cvs 4672: <h3><a name="sectc4220">Overflow</a></h3>
1.1 cvs 4673:
1.30 ! cvs 4674: <p>A boxes corresponding to a structural element normally contain all boxes
1.1 cvs 4675: corresponding to the elements of its subtree. However, in some cases, it
4676: could be necessary to allow a box to jut out from its parent box. Two
4677: presentation rules indicate that such an overflow is allowed, one for
1.18 cvs 4678: horizontal overflow, one for vertical overflow.</p>
1.30 ! cvs 4679:
! 4680: <p>Each of these rules is expressed by a keyword followed by a colon and the
1.18 cvs 4681: keyword <tt>Yes</tt> or <tt>No</tt>.</p>
4682: <pre> 'VertOverflow' ':' Boolean /
1.1 cvs 4683: 'HorizOverflow' ':' Boolean .
1.18 cvs 4684: Boolean = 'Yes' / 'No' .</pre>
4685: </div>
1.1 cvs 4686:
1.30 ! cvs 4687: <p>@@@@@ ******</p>
! 4688:
1.26 cvs 4689: <p>Explain Margin, Padding and Border. Refer to CSS2.</p>
4690: <pre> 'MarginTop' ':' MarginWidth /
4691: 'MarginRight' ':' MarginWidth /
4692: 'MarginBottom' ':' MarginWidth /
4693: 'MarginLeft' ':' MarginWidth /
4694: 'PaddingTop' ':' PaddingWidth /
4695: 'PaddingRight' ':' PaddingWidth /
4696: 'PaddingBottom' ':' PaddingWidth /
4697: 'PaddingLeft' ':' PaddingWidth /
4698: 'BorderTopWidth' ':' BorderWidth /
4699: 'BorderRightWidth' ':' BorderWidth /
4700: 'BorderBottomWidth' ':' BorderWidth /
4701: 'BorderLeftWidth' ':' BorderWidth /
4702: 'BorderTopColor' ':' BorderColor /
4703: 'BorderRightColor' ':' BorderColor /
4704: 'BorderBottomColor' ':' BorderColor /
4705: 'BorderLeftColor' ':' BorderColor /
4706: 'BorderTopStyle' ':' BorderStyle /
4707: 'BorderRightStyle' ':' BorderStyle /
4708: 'BorderBottomStyle' ':' BorderStyle /
4709: 'BorderLeftStyle' ':' BorderStyle .
4710:
4711: MarginWidth = InheritParent / 'Auto' / Distance .
4712: PaddingWidth = InheritParent / Distance .
4713: BorderWidth = InheritParent / 'Thin' / 'Medium' / 'Thick' / Distance .
4714: BorderColor = InheritParent / 'Transparent' / 'Foreground' /
4715: ColorName .
4716: BorderStyle = InheritParent /
4717: 'None' / 'Hidden' / 'Dotted' / 'Dashed' / 'Solid' /
4718: 'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
1.27 cvs 4719: InheritParent = 'Enclosing' '=' / 'Creator' '=' .
1.26 cvs 4720: ColorName = NAME .</pre>
1.30 ! cvs 4721:
! 4722: <p>@@@@@ ******</p>
1.26 cvs 4723:
1.18 cvs 4724: <div class="subsection">
1.30 ! cvs 4725: <h3><a name="sectc4221">Inheritance</a></h3>
1.1 cvs 4726:
1.30 ! cvs 4727: <p>A presentation parameter can be defined by reference to the same parameter
! 4728: of another box in the tree of boxes. These structural links are expressed by
1.1 cvs 4729: kinship. The reference box can be that of the element immediately above in
1.18 cvs 4730: the structure (<tt>Enclosing</tt>), two levels above (<tt>GrandFather</tt>),
4731: immediately below (<tt>Enclosed</tt>) or immediately before
4732: (<tt>Previous</tt>). In the case of a presentation box, and only in that
1.1 cvs 4733: case, the reference box may be the element which created the presentation box
1.18 cvs 4734: (<tt>Creator</tt>).</p>
1.30 ! cvs 4735:
! 4736: <p>Kinship is expressed in terms of the logical structure of the document and
! 4737: not in terms of the tree of boxes. The presentation box cannot transmit any
! 4738: of their parameters by inheritance; only structured element boxes can do so.
! 4739: As an example, consider an element B which follows an element A in the logical
1.1 cvs 4740: structure. The element B creates a presentation box P in front of itself,
1.18 cvs 4741: using the <tt>CreateBefore</tt> rule (see the <a href="#sectc4232">creation
4742: rules</a>). If element B's box inherits its character style using the
4743: <tt>Previous</tt> kinship operation, it gets its character style from A's box,
1.1 cvs 4744: not from P's box. Inheritance works differently for positions and extents,
1.18 cvs 4745: which can refer to presentation boxes.</p>
1.30 ! cvs 4746:
! 4747: <p>The inherited parameter value can be the same as that of the reference box.
1.1 cvs 4748: This is indicated by an equals sign. However, for numeric parameters, a
4749: different value can be obtained by adding or subtracting a number from the
4750: reference box's parameter value. Addition is indicated by a plus sign before
4751: the number, while subtraction is specified with a minus sign. The value of a
4752: parameter can also be given a maximum (if the sign is a plus) or minimum (if
1.18 cvs 4753: the sign is a minus).</p>
1.30 ! cvs 4754:
! 4755: <p>If the rule is being applied to a numeric attribute, the number to add or
1.1 cvs 4756: subtract can be replaced by the attribute name. The value of a maximum or
4757: minimum may also be replaced by an attribute name. In these cases, the value
1.18 cvs 4758: of the attribute is used.</p>
4759: <pre> Inheritance = Kinship InheritedValue .
1.6 cvs 4760: Kinship ='Enclosing' / 'GrandFather' / 'Enclosed' /
4761: 'Previous' / 'Creator' .
1.1 cvs 4762: InheritedValue ='+' PosIntAttr [ 'Max' maximumA ] /
1.6 cvs 4763: '-' NegIntAttr [ 'Min' minimumA ] /
4764: '=' .
4765: PosIntAttr = PosInt / AttrID .
4766: PosInt = NUMBER .
4767: NegIntAttr = NegInt / AttrID .
4768: NegInt = NUMBER .
4769: maximumA = maximum / AttrID .
4770: maximum = NUMBER .
4771: minimumA = minimum / AttrID .
1.18 cvs 4772: minimum = NUMBER .</pre>
1.30 ! cvs 4773:
! 4774: <p>The parameters which can be obtained by inheritance are justification,
1.1 cvs 4775: hyphenation, interline spacing, character font (font family), font style, font
4776: size, visibility, indentation, underlining, alignment of text, stacking order
4777: of objects, the style and thickness of lines, fill pattern and the colors of
1.18 cvs 4778: lines and characters.</p>
4779: </div>
1.1 cvs 4780:
1.18 cvs 4781: <div class="subsection">
1.30 ! cvs 4782: <h3><a name="sectc4222">Line breaking</a></h3>
1.1 cvs 4783:
1.30 ! cvs 4784: <p>The <tt>Line</tt> rule specifies that the contents of the box should be
! 4785: broken into lines: the boxes included in the box to which this rule is
! 4786: attached are displayed one after the other, from left to right, with their
! 4787: horizontal reference axes aligned so that they form a series of lines. The
! 4788: length of these lines is equal to the width of the box to which the
! 4789: <tt>Line</tt> rule is attached.</p>
! 4790:
! 4791: <p>When an included box overflows the current line, it is either carried
! 4792: forward to the next line, cur, or left the way it is. The <a
1.18 cvs 4793: href="#sectc4223"><tt>LineBreak</tt> rule</a> is used to allow or prevent the
1.1 cvs 4794: breaking of included boxes. If the included box is not breakable but is
4795: longer than the space remaining on the line, it is left as is. When a
4796: character string box is breakable, the line is broken between words or, if
1.18 cvs 4797: necessary, by <a href="#sectd42225">hyphenating a word</a>. When a compound
4798: box is breakable, the box is transparent in regard to line breaking. The boxes
4799: included in the compound box are treated just like included boxes which have
4800: the <tt>LineBreak</tt> rule. Thus, it is possible to traverse a complete
4801: subtree of boxes to line break the text leaves of a complex structure.</p>
1.30 ! cvs 4802:
! 4803: <p>The relative position rules of the included boxes are ignored, since the
! 4804: boxes will be placed according to the line breaking rules.</p>
! 4805:
! 4806: <p>The <tt>Line</tt> rule does not have a parameter. The characteristics of
! 4807: the lines that will be constructed are determined by the <tt>LineSpacing</tt>,
1.18 cvs 4808: <tt>Indent</tt>, <tt>Adjust</tt>, <tt>Justify</tt>, and <tt>Hyphenate</tt>
4809: rules. Moreover, the <a href="#insectd42226"><tt>Inline</tt> rule</a> permits
4810: the exclusion of certain elements from the line breaking process.</p>
1.30 ! cvs 4811:
! 4812: <p>When the <tt>Line</tt> rule appears in the rules sequence of a non-primary
1.18 cvs 4813: view, it applies only to that view, but when the <tt>Line</tt> rule appears in
1.1 cvs 4814: the rules sequence of the primary view, it also applies to the other views by
1.18 cvs 4815: default, except for those views which explicitly invoke the <tt>NoLine</tt>
4816: rule. Thus, the <tt>NoLine</tt> rule can be used in a non-primary view to
4817: override the primary view's <tt>Line</tt> rule. The <tt>NoLine</tt> rule must
4818: not be used with the primary view because the absence of the <tt>Line</tt>
4819: rule has the same effect. Like the <tt>Line</tt> rule, the <tt>NoLine</tt>
4820: rule does not take any parameters.</p>
4821: <pre> 'Line'
4822: 'NoLine'</pre>
4823:
4824: <div class="subsubsection">
1.30 ! cvs 4825: <h4><a name="sectd42221">Line spacing</a></h4>
1.18 cvs 4826:
1.30 ! cvs 4827: <p>The <tt>LineSpacing</tt> rule defines the line spacing to be used in the
! 4828: line breaking process. The line spacing is the distance between the baselines
1.1 cvs 4829: (horizontal reference axis) of the successive lines produced by the
1.18 cvs 4830: <tt>Line</tt> rule. The value of the line spacing can be specified as a
4831: constant or by inheritance. It is expressed in any of the available <a
4832: href="#sectc4217">distance units</a>.</p>
1.30 ! cvs 4833:
! 4834: <p>Inheritance allows the value to be obtained from a relative in the
! 4835: structure tree, either without change (an equals sign appears after the
! 4836: inheritance keyword), with a positive difference (a plus sign), or a negative
! 4837: difference (a minus sign). When the rule uses a difference, the value of the
! 4838: difference follows the sign and is expressed as a <a
! 4839: href="#sectc4217">distance</a>.</p>
1.18 cvs 4840: <pre> 'LineSpacing' ':' DistOrInherit
1.6 cvs 4841: DistOrInherit = Kinship InheritedDist / Distance .
1.18 cvs 4842: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .</pre>
1.30 ! cvs 4843:
! 4844: <p>When the line spacing value (or its difference from another element) is
1.1 cvs 4845: expressed in relative units, it changes with the size of the characters. Thus,
4846: when a larger font is chosen for a part of the document, the line spacing of
4847: that part expands proportionally. In contrast, when the line spacing value is
4848: expressed in absolute units (centimeters, inches, typographer's points), it is
4849: independent of the characters, which permits the maintenance of a consistent
4850: line spacing, whatever the character font. Either approach can be taken,
1.18 cvs 4851: depending on the desired effect.</p>
4852: </div>
1.1 cvs 4853:
1.18 cvs 4854: <div class="subsubsection">
1.30 ! cvs 4855: <h4><a name="sectd42222">First line indentation</a></h4>
1.1 cvs 4856:
1.30 ! cvs 4857: <p>The <tt>Indent</tt> rule is used to specify the indentation of the first
! 4858: line of the elements broken into lines by the <tt>Line</tt> function. The
1.1 cvs 4859: indentation determines how far the first line of the element is shifted with
4860: respect to the other lines of the same element. It can be specified as a
4861: constant or by inheritance. The constant value is a positive integer (shifted
4862: to the right; the sign is optional), a negative integer (shifted to the left)
1.18 cvs 4863: or zero (no shift). All available <a href="#sectc4217">units</a> can be
4864: used.</p>
1.30 ! cvs 4865:
! 4866: <p>Indentation can be defined for any box, regardless of whether the box is
! 4867: line broken, and transmitted by inheritance to elements that are line broken.
! 4868: The size of the indentation is specified in the same manner as the <a
1.18 cvs 4869: href="#sectd42221">line spacing</a>.</p>
4870: <pre> 'Indent' ':' DistOrInherit</pre>
4871: </div>
1.1 cvs 4872:
1.18 cvs 4873: <div class="subsubsection">
1.30 ! cvs 4874: <h4><a name="sectd42223">Alignment</a></h4>
1.1 cvs 4875:
1.30 ! cvs 4876: <p>The alignment style of the lines constructed during line breaking is
! 4877: defined by the <tt>Adjust</tt> rule. The alignment value can be a constant or
1.18 cvs 4878: inherited. A constant value is specified by a keyword:</p>
4879: <ul>
1.30 ! cvs 4880: <li><tt>Left</tt>: at the left edge,</li>
! 4881: <li><tt>Right</tt>: at the right edge,</li>
! 4882: <li><tt>VMiddle</tt>: centered</li>
! 4883: <li><tt>LeftWithDots</tt>: at the left edge with a dotted line filling out
! 4884: the last line up to the right edge of the line breaking box.</li>
1.18 cvs 4885: </ul>
1.30 ! cvs 4886:
! 4887: <p>An inherited value can only be the same as that of the reference box and is
1.18 cvs 4888: specified by a kinship keyword followed by an equals sign.</p>
4889: <pre> 'Adjust' ':' AlignOrInherit
1.1 cvs 4890: AlignOrInherit = Kinship '=' / Alignment .
4891: Alignment = 'Left' / 'Right' / 'VMiddle' /
1.18 cvs 4892: 'LeftWithDots' .</pre>
4893: </div>
1.1 cvs 4894:
1.18 cvs 4895: <div class="subsubsection">
1.30 ! cvs 4896: <h4><a name="sectd42224">Justification</a></h4>
1.1 cvs 4897:
1.30 ! cvs 4898: <p>The <tt>Justify</tt> rule indicates whether the lines contained in the box
! 4899: and produced by a <tt>Line</tt> rule should be extended horizontally to occupy
! 4900: the entire width of their enclosing box. The first and last lines are treated
1.1 cvs 4901: specially: the position of the beginning of the first line is fixed by the
1.18 cvs 4902: <tt>Indent</tt> rule and last line is not extended. The justification
1.1 cvs 4903: parameter defined by this rule takes a boolean value, which can be a constant
4904: or inherited. A constant boolean value is expressed by either the
1.18 cvs 4905: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 4906: same as that of the reference box and is specified by a kinship keyword
1.18 cvs 4907: followed by an equals sign.</p>
4908: <pre> 'Justify' ':' BoolInherit
1.1 cvs 4909: BoolInherit = Boolean / Kinship '=' .
1.18 cvs 4910: Boolean ='Yes' / 'No' .</pre>
1.30 ! cvs 4911:
! 4912: <p>When the lines are justified, the alignment parameter specified in the
1.18 cvs 4913: <tt>Adjust</tt> rule has no influence, other than on the last line produced.
1.1 cvs 4914: This occurs because, when the other are extended to the limits of the box, the
1.18 cvs 4915: alignment style is no longer perceptible.</p>
1.30 ! cvs 4916:
1.18 cvs 4917: <blockquote class="example">
1.30 ! cvs 4918: <p><strong>Example:</strong></p>
! 4919:
! 4920: <p>An important use of inheritance is to vary the characteristics of lines
! 4921: for an element type (for example, Paragraph) according to the enclosing
! 4922: environment (for example, Summary or Section), and thus obtain different
! 4923: line breaking styles for the same elements when they appear in different
! 4924: environments. The following rules specify that paragraphs inherit their
! 4925: alignment, justification, and line spacing:</p>
! 4926: <pre>Paragraph :
1.1 cvs 4927: BEGIN
4928: Justify : Enclosing = ;
4929: LineSpacing : Enclosing = ;
4930: Adjust : Enclosing =;
4931: Line;
1.18 cvs 4932: END;</pre>
1.30 ! cvs 4933:
! 4934: <p>If the alignment, justification, and line spacing of the Section and
! 4935: Summary elements is fixed:</p>
! 4936: <pre>Section :
1.1 cvs 4937: BEGIN
4938: Adjust : Left;
4939: Justify : Yes;
4940: LineSpacing : 1;
4941: END;
4942: Summary :
4943: BEGIN
4944: Adjust : VMiddle;
4945: Justify : No;
4946: LineSpacing : 1.3;
1.18 cvs 4947: END;</pre>
1.30 ! cvs 4948:
! 4949: <p>then the paragraphs appearing in sections are justified with a simple
! 4950: line spacing while those appearing in summaries are centered and not
! 4951: justified and have a larger line spacing. These are nevertheless the very
! 4952: same type of paragraph defined in the logical structure schema.</p>
1.18 cvs 4953: </blockquote>
4954: </div>
4955:
4956: <div class="subsubsection">
1.30 ! cvs 4957: <h4><a name="sectd42225">Hyphenation</a></h4>
1.18 cvs 4958:
1.30 ! cvs 4959: <p>The <tt>Hyphenate</tt> rule indicates whether or not words should be broken
! 4960: by hyphenation at the end of lines. It affects the lines produced by the
1.18 cvs 4961: <tt>Line</tt> rule and contained in the box carrying the <tt>Hyphenate</tt>
4962: rule.</p>
1.30 ! cvs 4963:
! 4964: <p>The hyphenation parameter takes a boolean value, which can be either
! 4965: constant or inherited. A constant boolean value is expressed by either the
1.18 cvs 4966: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 4967: same as that of the reference box and is specified by a kinship keyword
1.18 cvs 4968: followed by an equals sign.</p>
4969: <pre> 'Hyphenate' ':' BoolInherit
1.1 cvs 4970: BoolInherit = Boolean / Kinship '=' .
1.18 cvs 4971: Boolean = 'Yes' / 'No' .</pre>
4972: </div>
4973:
4974: <div class="subsubsection">
1.30 ! cvs 4975: <h4><a name="sectd42226">Avoiding line breaking</a></h4>
1.18 cvs 4976:
1.30 ! cvs 4977: <p>The <tt>InLine</tt> rule is used to specify that a box that would otherwise
1.18 cvs 4978: participate in line breaking asked for by the <tt>Line</tt> rule of an
1.1 cvs 4979: enclosing box, instead avoids the line breaking process and positions itself
1.18 cvs 4980: according to the <tt>HorizPos</tt> and <tt>VertPos</tt> rules that apply to
4981: it. When the <tt>InLine</tt> rule applies to a box which would not be line
4982: broken, it has no effect.</p>
1.30 ! cvs 4983:
! 4984: <p>The rule is expressed by the <tt>InLine</tt> keyword followed by a colon
! 4985: and the keyword <tt>Yes</tt>, if the box should participate in line breaking,
! 4986: or the keyword <tt>No</tt>, if it should not. This is the only form possible:
1.1 cvs 4987: this rule cannot be inherited. Moreover, it can only appear in the rules of
4988: the primary view and applies to all views defined in the presentation
1.18 cvs 4989: schema.</p>
4990: <pre> 'InLine' ':' Boolean .
4991: Boolean = 'Yes' / 'No' .</pre>
1.30 ! cvs 4992:
1.18 cvs 4993: <blockquote class="example">
1.30 ! cvs 4994: <p><strong>Example:</strong></p>
! 4995:
! 4996: <p>Suppose the structure schema defines a logical attribute called
! 4997: <tt>New</tt> which is used to identify the passages in a document which were
! 4998: recently modified. It would be nice to have the presentation schema make a
! 4999: bar appear in the left margin next to each passage having the <tt>New</tt>
! 5000: attribute. A new passage can be an entire element, such as a paragraph or
! 5001: section, or it can be some words in the middle of a paragraph. To produce
! 5002: the desired effect, the <tt>New</tt> attribute is given a creation rule
! 5003: which generates a <tt>VerticalBar</tt> presentation box.</p>
! 5004:
! 5005: <p>When the <tt>New</tt> attribute is attached to a character string which
! 5006: is inside a line broken element (inside a paragraph, for example), the bar
! 5007: is one of the elements which participates in line breaking and it is placed
! 5008: normally in the current line, at the end of the character string which has
! 5009: the attribute. To avoid this, the <tt>InLine</tt> rule is used in the
! 5010: following way:</p>
! 5011: <pre>BOXES
1.1 cvs 5012: VerticalBar:
5013: BEGIN
5014: Content: Graphics 'l';
5015: HorizPos: Left = Root . Left;
5016: VertPos: Top = Creator . Top;
5017: Height: Bottom = Creator . Bottom;
5018: Width: 1 pt;
5019: InLine: No;
5020: ...
5021: END;
5022: ...
5023: ATTRIBUTES
5024: Nouveau:
5025: BEGIN
5026: CreateAfter(VerticalBar);
1.18 cvs 5027: END;</pre>
5028: </blockquote>
5029: </div>
5030: </div>
1.1 cvs 5031:
1.18 cvs 5032: <div class="subsection">
1.30 ! cvs 5033: <h3><a name="sectc4223">Page breaking and line breaking conditions</a></h3>
1.1 cvs 5034:
1.30 ! cvs 5035: <p>Pages are constructed by the editor in accordance with the model specified
! 5036: by a <a href="#sectc4233"><tt>Page</tt> rule</a>. The page model describes
! 5037: only the composition of the pages but does not give any rules for breaking
1.18 cvs 5038: different element types across pages. Now, it is possible that certain
5039: elements must not be cut by page breaks, while others can be cut anywhere. The
5040: <tt>PageBreak</tt>, <tt>NoBreak1</tt>, and <tt>NoBreak2</tt> rules are used to
5041: specify the conditions under which each element type can be cut.</p>
1.30 ! cvs 5042:
! 5043: <p>The <tt>PageBreak</tt> rule is used to indicate whether or not the box can
! 5044: be cut during the construction of pages. If cutting is authorized, the box
! 5045: can be cut, with one part appearing at the bottom of a page and the other part
1.1 cvs 5046: appearing at the top of the next page. The rule is formed by the
1.18 cvs 5047: <tt>PageBreak</tt> keyword followed by a colon and a constant boolean value
5048: (<tt>Yes</tt> or <tt>No</tt>). This is the only form possible: this rule
1.1 cvs 5049: cannot be inherited. Moreover, it can only appear in the rules of the primary
1.18 cvs 5050: view and applies to all views defined in the presentation schema.</p>
1.30 ! cvs 5051:
! 5052: <p>Whether objects can be cut by line breaks can be controlled in a similar
! 5053: way using the <tt>LineBreak</tt> rule. This rule allows the specification of
1.1 cvs 5054: whether or not the box can be cut during the construction of lines. If
5055: cutting is authorized, the box can be cut, with one part appearing at the end
5056: of a line and the other part appearing at the beginning of the next line. The
1.18 cvs 5057: rule is formed by the <tt>LineBreak</tt> keyword followed by a colon and a
5058: constant boolean value (<tt>Yes</tt> or <tt>No</tt>). This is the only form
1.1 cvs 5059: possible: this rule cannot be inherited. Moreover, it can only appear in the
5060: rules of the primary view and applies to all views defined in the presentation
1.18 cvs 5061: schema.</p>
5062: <pre> 'PageBreak' ':' Boolean .
1.1 cvs 5063: 'LineBreak' ':' Boolean .
1.18 cvs 5064: Boolean = 'Yes' / 'No' .</pre>
1.30 ! cvs 5065:
! 5066: <p>When a box can be cut by a page break, it is possible that a page break
! 5067: will fall an inappropriate spot, creating, for example, a widow or orphan, or
1.1 cvs 5068: separating the title of a section from the first paragraph of the section. The
1.18 cvs 5069: <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules are used to avoid this. They
5070: specify that the box of the element to which they apply cannot be cut within a
5071: certain zone at the top (<tt>NoBreak1</tt> rule) or at the bottom
5072: (<tt>NoBreak2</tt> rule). These two rules specify the height of the zones in
5073: which page breaks are prohibited.</p>
1.30 ! cvs 5074:
! 5075: <p>The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules give the height of the
! 5076: zone in which page breaking is prohibited. The height is given as a constant
! 5077: value using any of the <a href="#sectc4217">available units</a>, absolute or
1.18 cvs 5078: relative. The value may not be inherited.</p>
5079: <pre> 'NoBreak1' ':' AbsDist .
5080: 'NoBreak2' ':' AbsDist .</pre>
1.30 ! cvs 5081:
1.18 cvs 5082: <blockquote class="example">
1.30 ! cvs 5083: <p><strong>Example:</strong></p>
! 5084:
! 5085: <p>The following rules prevent widows and orphans in a paragraph:</p>
! 5086: <pre>Paragraph :
1.1 cvs 5087: BEGIN
5088: NoBreak1 : 2;
5089: NoBreak2 : 2;
1.18 cvs 5090: END;</pre>
1.30 ! cvs 5091:
! 5092: <p>This rule prevents a section title from becoming separated from the first
! 5093: paragraph of the section by prohibiting page breaks at the beginning of the
! 5094: section rule:</p>
! 5095: <pre>Section :
1.18 cvs 5096: NoBreak1 : 1.5 cm;</pre>
1.30 ! cvs 5097:
! 5098: <p>Finally, this rule prevents a figure from being page broken in any
! 5099: way:</p>
! 5100: <pre>Figure :
1.18 cvs 5101: PageBreak : No;</pre>
5102: </blockquote>
1.30 ! cvs 5103:
! 5104: <p>The Thot editor constructs the document images displayed on the screen
1.1 cvs 5105: dynamically. As the user moves in the document or makes the document scroll
5106: in a window, the editor constructs the image to be displayed in little bits,
5107: filling the gaps which are produced in the course of these operations. It
5108: stops filling in the image when an element reaches the edge of the window in
5109: which the gap appears. If the appearance of the document is complex, it is
5110: possible that the image in incomplete, even though the edge of the window was
5111: reached. For example, an element might need to be presented to the side of
5112: the last element displayed, but its image was not constructed. The user will
5113: not know whether the element is really absent or if its image has simply not
1.18 cvs 5114: been constructed.</p>
1.30 ! cvs 5115:
! 5116: <p>The <tt>Gather</tt> rule is used to remedy this problem. When the rule
1.18 cvs 5117: <tt>Gather : Yes;</tt> is associated with an element type, the image of such
5118: elements is constructed as a block by the editor: it is never split up.</p>
1.30 ! cvs 5119:
! 5120: <p>The <tt>Gather</tt> rule may not appear in the <a href="#sectc427">default
1.18 cvs 5121: rules</a>. Elements which do not have the <tt>Gather</tt> rule are considered
5122: susceptible to being split up during display. Thus, it is not necessary to
5123: use the <tt>Gather : No;</tt> form. This rule must be used prudently and only
5124: for those elements which truly need it. If used incorrectly, it can
5125: pointlessly increase the size of the image constructed by the editor and lead
5126: to excessive memory consumption by the editor.</p>
1.30 ! cvs 5127:
! 5128: <p>Like the <tt>PageBreak</tt> and <tt>LineBreak</tt> rules, the
! 5129: <tt>Gather</tt> rule can only appear in rules of the primary view and applies
! 5130: to all views defined in the presentation schema.</p>
1.18 cvs 5131: <pre> 'Gather' ':' Boolean .</pre>
5132: </div>
1.1 cvs 5133:
1.18 cvs 5134: <div class="subsection">
1.30 ! cvs 5135: <h3><a name="sectc4224">Visibility</a></h3>
1.1 cvs 5136:
1.30 ! cvs 5137: <p>The visibility parameter is used to control which elements should or should
1.1 cvs 5138: not be displayed, based on context. An element can have different
5139: visibilities in different views. If an element's visibility is zero for a
5140: view, that element is not displayed in that view and does not occupy any space
1.18 cvs 5141: (its extents are zero).</p>
1.30 ! cvs 5142:
! 5143: <p>Visibility takes non-negative integer values (positive or zero). If values
1.1 cvs 5144: greater than 1 are used, they allow the user to choose a degree of visibility
5145: and, thus, to see only those boxes whose visibility parameter exceeds a
5146: certain threshold. This gives the user control over the granularity of the
1.18 cvs 5147: displayed pictures.</p>
1.30 ! cvs 5148:
! 5149: <p>The visibility parameter can be defined as a constant or by inheritance. If
1.1 cvs 5150: defined by inheritance, it cannot be based on the value of the next or
1.18 cvs 5151: previous box. Visibility can only be inherited from above.</p>
1.30 ! cvs 5152:
! 5153: <p>If it is a numeric attribute's presentation rule, the visibility can be
1.1 cvs 5154: specified by the attribute's name, in which case the value of the attribute is
1.18 cvs 5155: used.</p>
5156: <pre> 'Visibility' ':' NumberInherit
1.1 cvs 5157: NumberInherit = Integer / AttrID / Inheritance .
1.18 cvs 5158: Integer = NUMBER .</pre>
1.30 ! cvs 5159:
1.18 cvs 5160: <blockquote class="example">
1.30 ! cvs 5161: <p><strong>Example:</strong></p>
! 5162:
! 5163: <p>Suppose that only <tt>Formula</tt> elements should be displayed in the
! 5164: <tt>MathView</tt> view. Then, the default rules should include:</p>
! 5165: <pre>DEFAULT
1.18 cvs 5166: IN MathView Visibility:0;</pre>
1.30 ! cvs 5167:
! 5168: <p>which makes all elements invisible in the <tt>MathView</tt> view.
! 5169: However, the <tt>Formula</tt> element also has a <tt>Visibility</tt>
! 5170: rule:</p>
! 5171: <pre>Formula :
1.18 cvs 5172: IN MathView Visibility:5;</pre>
1.30 ! cvs 5173:
! 5174: <p>which makes formulas, and only formulas, visible.</p>
1.18 cvs 5175: </blockquote>
5176: </div>
1.1 cvs 5177:
1.18 cvs 5178: <div class="subsection">
1.30 ! cvs 5179: <h3><a name="sectc4225">Character style parameters</a></h3>
1.1 cvs 5180:
1.30 ! cvs 5181: <p>Four parameters are used to determine which characters are used to display
1.18 cvs 5182: text. They are size, font, style, and underlining.</p>
1.1 cvs 5183:
1.18 cvs 5184: <div class="subsubsection">
1.30 ! cvs 5185: <h4><a name="sectd42251">Character size</a></h4>
! 5186:
! 5187: <p>The size parameter has two effects. First, it is used to specify the
! 5188: actual size and distance units for boxes defined in <a
! 5189: href="#sectc4217">relative units</a>. Second, it defines the size of the
! 5190: characters contained in the box.</p>
1.1 cvs 5191:
1.30 ! cvs 5192: <p>As a distance or length, the size can be expressed in abstract or absolute
1.1 cvs 5193: units. It can also be inherited. If it is not inherited, it is expressed
1.18 cvs 5194: simply as an integer followed by the <tt>pt</tt> keyword, which indicates that
5195: the size is expressed in typographer's points. The absence of the <tt>pt</tt>
1.1 cvs 5196: keyword indicates that it is in abstract units in which the value 1 represents
5197: the smallest size while the value 16 is the largest size. The relationship
5198: between these abstract sizes and the real character sizes is controlled by a
5199: table which can be modified statically or even dynamically during the
1.18 cvs 5200: execution of the Thot editor.</p>
1.30 ! cvs 5201:
! 5202: <p>If the <tt>Size</tt> rule is a numeric attribute's presentation rule, the
! 5203: value of the size parameter can be specified by the attribute's name, in which
! 5204: case the value of the attribute is used.</p>
! 5205:
! 5206: <p><strong>Note:</strong> the only unit available for defining an absolute
! 5207: size is the typographer's point. Centimeters and inches may not be used.</p>
! 5208:
! 5209: <p>If the size is inherited, the rule must specify the relative from which to
! 5210: inherit and any percentage or difference from that relative's value. A
! 5211: percentage is indicated by a <tt>*</tt> followed by the value of the
! 5212: percentage and a <tt>%</tt>. A difference can be expressed in either
! 5213: typographer's points or in abstract units and the maximum or minimum size can
! 5214: be specified, but without specifying the unit: it is the same as was specified
! 5215: for the difference.</p>
! 5216:
! 5217: <p>In a numeric attribute's presentation rule, the difference in size or the
1.22 cvs 5218: percentage can be indicated by the attribute's name instead of the numeric
5219: value, which means that the attribute's value should be used as the difference
5220: or percentage. The attribute can also be used as the minimum or maximum size
5221: for a difference.</p>
5222: <pre> 'Size' ':' SizeInherit
5223: SizeInherit = SizeAttr [ 'pt' ] /
5224: Kinship InheritedSize .
5225: InheritedSize ='+' SizeAttr [ 'pt' ]
5226: [ 'Max' MaxSizeAttr ] /
5227: '-' SizeAttr [ 'pt' ]
5228: [ 'Min' MinSizeAttr ] /
5229: '*' PercentSizeAttr '%' /
5230: '=' .
5231: SizeAttr = Size / AttrID .
5232: Size = NUMBER .
5233: MaxSizeAttr = MaxSize / AttrID .
5234: MaxSize = NUMBER .
5235: MinSizeAttr = MinSize / AttrID .
5236: MinSize = NUMBER .
5237: PercentSizeAttr = PercentSize / AttrID .
5238: PercentSize = NUMBER .</pre>
1.30 ! cvs 5239:
1.18 cvs 5240: <blockquote class="example">
1.30 ! cvs 5241: <p><strong>Example:</strong></p>
! 5242:
! 5243: <p>The rule</p>
! 5244: <pre>Size : Enclosing - 2 pt Min 7;</pre>
! 5245:
! 5246: <p>states that the character size is 2 points less than that of the
! 5247: enclosing box, but that it may not be less than 7 points, whatever the
! 5248: enclosing box's value.</p>
! 5249:
! 5250: <p>The following rules make the text of a report be displayed with
! 5251: medium-sized characters (for example, size 5), while the title is displayed
! 5252: with larger characters and the summary is displayed with smaller
! 5253: characters:</p>
! 5254: <pre>Report :
1.1 cvs 5255: Size : 5;
5256: Title :
5257: Size : Enclosing + 2;
5258: Summary :
1.18 cvs 5259: Size : Enclosing - 1;</pre>
1.30 ! cvs 5260:
! 5261: <p>Thus, the character sizes in the entire document can be changed by
! 5262: changing the size parameter of the Report element, while preserving the
! 5263: relationships between the sizes of the different elements.</p>
1.18 cvs 5264: </blockquote>
5265: </div>
5266:
5267: <div class="subsubsection">
1.30 ! cvs 5268: <h4><a name="sectd42252">Font and character style</a></h4>
1.18 cvs 5269:
1.30 ! cvs 5270: <p>The <tt>Font</tt> rule determines the font family to be used to display the
1.18 cvs 5271: characters contained in the box, while the <tt>Style</tt> rule determines
1.23 cvs 5272: their style and the <tt>Weight</tt> rule determines their weight. Thot
5273: recognizes three character fonts (Times, Helvetica, and Courier), three
5274: styles: Roman, Italics, and Oblique, and two weights: Normal and Bold.</p>
1.30 ! cvs 5275:
! 5276: <p>The font family, style and weight can be specified by a named constant or
! 5277: can be inherited. For the name of the font family only the first character is
! 5278: used.</p>
! 5279:
! 5280: <p>Only identical inheritance is allowed: the box takes the same font, style
! 5281: or weight as the box from which it inherits. This is indicated by an equals
1.23 cvs 5282: sign after the kinship specification.</p>
5283: <pre> 'Font' ':' NameInherit /
5284: 'Style' ':' StyleInherit /
5285: 'Weight' ':' WeightInherit /
5286:
5287: NameInherit = Kinship '=' / FontName .
5288: FontName = NAME .
5289: StyleInherit = Kinship '=' /
5290: 'Roman' / 'Italics' / 'Oblique' .
5291: WeightInherit = Kinship '=' /
5292: 'Normal' / 'Bold' .</pre>
1.30 ! cvs 5293:
1.18 cvs 5294: <blockquote class="example">
1.30 ! cvs 5295: <p><strong>Example:</strong></p>
! 5296:
! 5297: <p>To specify that the summary uses the font family of the rest of the
! 5298: document, but in the italic style, the following rules are used:</p>
! 5299: <pre>Summary :
1.1 cvs 5300: BEGIN
5301: Font : Enclosing =;
5302: Style : Italics;
1.18 cvs 5303: END;</pre>
5304: </blockquote>
5305: </div>
5306:
5307: <div class="subsubsection">
1.30 ! cvs 5308: <h4><a name="sectd42253">Underlining</a></h4>
1.18 cvs 5309:
1.30 ! cvs 5310: <p>The <tt>Underline</tt> rule is used to specify if the characters contained
! 5311: in a box should have lines drawn on or near them. There are four underlining
1.18 cvs 5312: styles: <tt>Underlined</tt>, <tt>Overlined</tt>, <tt>CrossedOut</tt>, and
5313: <tt>NoUnderline</tt>. The <tt>Thickness</tt> rule specifies the thickness of
5314: the line, <tt>Thin</tt> or <tt>Thick</tt>.</p>
1.30 ! cvs 5315:
! 5316: <p>As with font family and style, only identical inheritance is allowed: the
! 5317: box has the same underlining type as the box from which it inherits the value.
1.18 cvs 5318: This is indicated by an equals sign after the kinship specification.</p>
5319: <pre> 'Underline' ':' UnderLineInherit /
1.1 cvs 5320: 'Thickness' ':' ThicknessInherit /
5321:
5322: UnderLineInherit = Kinship '=' / 'NoUnderline' /
5323: 'Underlined' /
5324: 'Overlined' / 'CrossedOut' .
1.18 cvs 5325: ThicknessInherit = Kinship '=' / 'Thick' / 'Thin' .</pre>
5326: </div>
5327: </div>
5328:
5329: <div class="subsection">
1.30 ! cvs 5330: <h3><a name="sectc4226">Stacking order</a></h3>
1.18 cvs 5331:
1.30 ! cvs 5332: <p>The <tt>Depth</tt> rule is used to define the stacking order of terminal
! 5333: boxes when multiple boxes at least partially overlap. This rule defines how
! 5334: the depth parameter, which is zero or a positive integer, is calculated. The
1.1 cvs 5335: depth parameter has a value for all boxes. For terminal boxes in the
5336: structure and for presentation boxes, the depth value is used during display
5337: and printing: the boxes with the lowest value overlap those with higher
5338: depths. For non-terminal boxes, the depth is not interpreted during display,
1.18 cvs 5339: but it is used to calculate the depth of terminal boxes by inheritance.</p>
1.30 ! cvs 5340:
! 5341: <p>Like most other rules, the depth rule is defined in the <a
1.18 cvs 5342: href="#sectc427">default rules</a> of each presentation schema. Thus, there
5343: is always a depth value, even when it is not necessary because there is no
5344: overlapping. To avoid useless operations, a zero value can be given to the
5345: depth parameter, which signifies that overlapping is never a problem.</p>
1.30 ! cvs 5346:
! 5347: <p>The depth rule has the same form as the <a href="#sectc4224">visibility
1.18 cvs 5348: rule</a>. It can be defined by inheritance or by a constant numeric value.
5349: When the rule is attached to a numeric attribute, it can take the value of
5350: that attribute.</p>
5351: <pre> 'Depth' ':' NumberInherit</pre>
1.30 ! cvs 5352:
1.18 cvs 5353: <blockquote class="example">
1.30 ! cvs 5354: <p><strong>Example:</strong></p>
! 5355:
! 5356: <p>For a purely textual document, in which overlapping never poses a
! 5357: problem, a single default <tt>Depth</tt> rule in the presentation schema is
! 5358: sufficient:</p>
! 5359: <pre>DEFAULT
1.1 cvs 5360: Depth : 0;
1.18 cvs 5361: ...</pre>
1.30 ! cvs 5362:
! 5363: <p>To make the text of examples appear on a light blue background, a
! 5364: presentation box is defined:</p>
! 5365: <pre>BOXES
1.1 cvs 5366: BlueBG :
5367: BEGIN
5368: Content : Graphics 'R';
5369: Background : LightBlue3;
5370: FillPattern: backgroundcolor;
5371: Depth : 2;
5372: ...
1.18 cvs 5373: END;</pre>
1.30 ! cvs 5374:
! 5375: <p>and is created by the <tt>Example</tt> element, which has the rules:</p>
! 5376: <pre>RULES
1.1 cvs 5377: Example :
5378: BEGIN
5379: CreateFirst (BlueBG);
5380: Depth : 1;
5381: ...
1.18 cvs 5382: END;</pre>
1.30 ! cvs 5383:
! 5384: <p>In this way, the text of an example (if it inherits its depth from its
! 5385: ancestor) will be superimposed on a light blue background, and not the
! 5386: reverse).</p>
1.18 cvs 5387: </blockquote>
5388: </div>
5389:
5390: <div class="subsection">
1.30 ! cvs 5391: <h3><a name="sectc4227">Line style</a></h3>
1.18 cvs 5392:
1.30 ! cvs 5393: <p>The <tt>LineStyle</tt> rule determines the style of line which should be
! 5394: used to draw all the elements contained in the box and the box itself, if it
! 5395: has a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. The line style can be
1.18 cvs 5396: indicated by a name (<tt>Solid</tt>, <tt>Dashed</tt>, <tt>Dotted</tt>) or it
1.13 cvs 5397: can be inherited. All elements of the graphic base type are affected by this
1.1 cvs 5398: rule, but it can be attached to any box and transmitted by inheritance to the
1.18 cvs 5399: graphic elements. The border of elements having a <a
5400: href="#sectc4230a"><tt>ShowBox</tt> rule</a> is drawn according to the line
5401: style specified by this rule.</p>
1.30 ! cvs 5402:
! 5403: <p>Only identical inheritance is allowed: the box takes the same line style as
1.1 cvs 5404: the box from which it inherits. This is indicated by an equals sign after the
1.18 cvs 5405: kinship specification.</p>
5406: <pre> 'LineStyle' ':' LineStyleInherit
1.1 cvs 5407: LineStyleInherit = Kinship '=' /
1.18 cvs 5408: 'Solid' / 'Dashed' / 'Dotted' .</pre>
1.30 ! cvs 5409:
1.18 cvs 5410: <blockquote class="example">
1.30 ! cvs 5411: <p><strong>Example:</strong></p>
! 5412:
! 5413: <p>To specify that, in Figures, the graphical parts should be drawn in solid
! 5414: lines, the Figure element is given a rule using the <tt>Solid</tt> name:</p>
! 5415: <pre>Figure :
1.18 cvs 5416: LineStyle : Solid;</pre>
1.30 ! cvs 5417:
! 5418: <p>and the elements composing figures are given an inheritance rule:</p>
! 5419: <pre> LineStyle : Enclosing =;</pre>
1.18 cvs 5420: </blockquote>
5421: </div>
5422:
5423: <div class="subsection">
1.30 ! cvs 5424: <h3><a name="sectc4228">Line thickness</a></h3>
1.18 cvs 5425:
1.30 ! cvs 5426: <p>The <tt>LineWeight</tt> rule determines the thickness of the lines of all
1.1 cvs 5427: graphical elements which appear in the box, no matter what their line style.
5428: Line thickness can be specified by a constant value or by inheritance. A
5429: constant value is a positive number followed by an optional unit specification
1.18 cvs 5430: (which is absent when using relative units). All available <a
5431: href="#sectc4217">distance units</a> can be used. Line thickness is expressed
5432: in the same way as <a href="#sectd42221">line spacing</a>.</p>
5433: <pre> 'LineWeight' ':' DistOrInherit</pre>
1.30 ! cvs 5434:
! 5435: <p>All elements of the graphic base type are affected by this rule, but it can
! 5436: be attached to any box and transmitted by inheritance to the graphic elements.
1.18 cvs 5437: The border of element having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>
5438: is also drawn according to the thickness specified by this rule.</p>
1.30 ! cvs 5439:
1.18 cvs 5440: <blockquote class="example">
1.30 ! cvs 5441: <p><strong>Example:</strong></p>
! 5442:
! 5443: <p>To specify that, in Figures, the graphical parts should be drawn with
! 5444: lines 0.3 pt thick, the Figure element is given this rule:</p>
! 5445: <pre>Figure :
1.18 cvs 5446: LineWeight : 0.3 pt;</pre>
1.30 ! cvs 5447:
! 5448: <p>and the elements composing figures are given an inheritance rule:</p>
! 5449: <pre> LineWeight : Enclosing =;</pre>
1.18 cvs 5450: </blockquote>
5451: </div>
5452:
5453: <div class="subsection">
1.30 ! cvs 5454: <h3><a name="sectc4229">Fill pattern</a></h3>
1.18 cvs 5455:
1.30 ! cvs 5456: <p>The <tt>FillPattern</tt> rule determines the pattern used to fill closed
1.1 cvs 5457: graphical elements (circles, rectangles, etc.) which appear in the box. This
1.18 cvs 5458: rule also specifies the pattern used to fill the box associated with elements
5459: having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a><a>. This pattern can
5460: be indicated by a named constant or by inheritance. The named constant
5461: identifies one of the patterns available in Thot. The names of the available
5462: patterns are: nopattern, foregroundcolor, backgroundcolor, gray1, gray2,
5463: gray3, gray4, gray5, gray6, gray7, horiz1, horiz2, horiz3, vert1, vert2,
5464: vert3, left1, left2, left3, right1, right2, right3, square1, square2, square3,
5465: lozenge, brick, tile, sea, basket.</a></p>
1.30 ! cvs 5466:
! 5467: <p>Like the other rules peculiar to graphics, <tt>LineStyle</tt> and
1.18 cvs 5468: <tt>LineWeight</tt>, only elements of the graphic base type are affected by
5469: the <tt>FillPattern</tt> rule, but the rule can be attached to any box and
1.1 cvs 5470: transmitted by inheritance to the graphic elements. As with the other rules
1.18 cvs 5471: specific to graphics, only identical inheritance is allowed.</p>
1.30 ! cvs 5472:
! 5473: <p>The <tt>FillPattern</tt> rule can also be used to determine whether or not
1.12 cvs 5474: text characters, symbols and pictures should be colored. For these element
5475: types (text, symbols, and pictures), the only valid values are
1.18 cvs 5476: <tt>nopattern</tt>, <tt>foregroundcolor</tt>, and <tt>backgroundcolor</tt>.
5477: When <tt>FillPattern</tt> has the value <tt>backgroundcolor</tt>, text
5478: characters, symbols, and bitmaps are given the color specified by the <a
5479: href="#sectc4230"><tt>Background</tt> rule</a> which applies to these
5480: elements. When <tt>FillPattern</tt> has the value <tt>foregroundcolor</tt>,
5481: these same elements are given the color specified by the <a
5482: href="#sectc4230"><tt>Foreground</tt> rule</a> which applies to these
5483: elements. In all other case, text characters are not colored.</p>
5484: <pre> 'FillPattern' ':' NameInherit</pre>
1.30 ! cvs 5485:
1.18 cvs 5486: <blockquote class="example">
1.30 ! cvs 5487: <p><strong>Example:</strong></p>
! 5488:
! 5489: <p>To specify that, in Figures, the closed graphical elements should be
! 5490: filled with a pattern resembling a brick wall, the Figure element is given
! 5491: this rule:</p>
! 5492: <pre>Figure :
1.18 cvs 5493: FillPattern : brick;</pre>
1.30 ! cvs 5494:
! 5495: <p>and the elements composing figures are given an inheritance rule:</p>
! 5496: <pre> FillPattern : Enclosing =;</pre>
1.18 cvs 5497: </blockquote>
5498: </div>
5499:
5500: <div class="subsection">
1.30 ! cvs 5501: <h3><a name="sectc4230">Colors</a></h3>
1.18 cvs 5502:
1.30 ! cvs 5503: <p>The <tt>Foreground</tt> and <tt>Background</tt> rules determine the
! 5504: foreground and background colors of the base elements which appear in the box.
! 5505: They also control the color of boxes associated with elements having a <a
1.18 cvs 5506: href="#sectc4230a"><tt>ShowBox</tt> rule</a>. These colors can be specified
5507: with a named constant or by inheritance. The named constants specify one of
5508: the available colors in Thot. The available color names can be found in the
1.30 ! cvs 5509: file <tt>thot.color</tt>. In addition to those names, you can use the keyword
! 5510: <code>Transparent</code>, to not draw anything.</p>
! 5511:
! 5512: <p>The color rules affect the same way all base elements and elements having a
! 5513: <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>, no matter what their type
! 5514: (text, graphics, pictures, symbols). The color rules can be associated with
! 5515: any box and can be transmitted by inheritance to the base elements or the
! 5516: elements having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. Like the
! 5517: preceding rules, only inheritance of the same value is allowed.</p>
! 5518: <pre> 'Foreground' ':' Color
! 5519: 'Background' ':' Color
! 5520: Color = 'Transparent' / Link '=' / FontColorName .</pre>
! 5521:
! 5522: <p><strong>Note:</strong> text colors only appear for text elements whose <a
1.18 cvs 5523: href="#sectc4229">fill pattern</a> does not prevent the use of color.</p>
1.30 ! cvs 5524:
1.18 cvs 5525: <blockquote class="example">
1.30 ! cvs 5526: <p><strong>Example:</strong></p>
! 5527:
! 5528: <p>To specify that, in Figures, everything must be drawn in blue on a
! 5529: background of yellow, the Figure element is given these rules:</p>
! 5530: <pre>Figure :
1.1 cvs 5531: BEGIN
5532: Foreground : Blue;
5533: Background : Yellow;
5534: Fillpattern : backgroundcolor;
1.18 cvs 5535: END;</pre>
1.30 ! cvs 5536:
! 5537: <p>and the elements composing figures are given inheritance rules:</p>
! 5538: <pre> Foreground : Enclosing =;
1.1 cvs 5539: Background : Enclosing =;
1.18 cvs 5540: FillPattern : Enclosing =;</pre>
5541: </blockquote>
5542: </div>
5543:
5544: <div class="subsection">
1.30 ! cvs 5545: <h3><a name="sectc4230a">Background color and border</a></h3>
1.18 cvs 5546:
1.30 ! cvs 5547: <p>Boxes associated with structural elements are normally not visible, but it
! 5548: is possible to draw their border and/or to paint their area when it is needed.
1.18 cvs 5549: This is achieved by associating the <tt>ShowBox</tt> rule with the concerned
1.13 cvs 5550: element. This rule has no parameter and no value. It is simply written
1.18 cvs 5551: <tt>Showbox;</tt>. It is not inherited nor transmitted to any other element.
5552: It applies only to the element with which it is associated.</p>
5553: <pre> 'ShowBox'</pre>
1.30 ! cvs 5554:
! 5555: <p>When an element has a <tt>ShowBox</tt> rule, the border is drawn only if
! 5556: the <tt>LineWeight</tt> rule that applies to that element has a non-zero value
1.18 cvs 5557: (this value can be inherited). The color, style and thickness of the border
5558: are defined by the <tt>Foreground</tt>, <tt>LineStyle</tt>, and
5559: <tt>LineWeight</tt> rules that apply to the element.</p>
1.30 ! cvs 5560:
! 5561: <p>When an element has a <tt>ShowBox</tt> rule, the background of this element
! 5562: is paint only if the value of the <tt>FillPattern</tt> rule that applies to
! 5563: that element is not <tt>nopattern</tt>. The pattern and color(s) of the
! 5564: background are defined by the <tt>FillPattern</tt>, <tt>Background</tt>, and
1.18 cvs 5565: <tt>Foreground</tt> rules that apply to the element.</p>
5566: </div>
5567:
5568: <div class="subsection">
1.30 ! cvs 5569: <h3><a name="sectc4230b">Background pictures</a></h3>
1.18 cvs 5570:
1.30 ! cvs 5571: <p>The <tt>BackgroundPicture</tt> rule allows to display a picture as the
1.13 cvs 5572: background of an element. It has a single parameter, the file name of the
1.18 cvs 5573: picture. This is a string delimited by single quotes. If the first character
5574: in this string is '/', it is considered as an absolute path, otherwise the
5575: file is searched for along the schema directory path. This file may contain a
5576: picture in any format accepted by Thot (xbm, xpm, gif, jpeg, png, etc.)</p>
1.30 ! cvs 5577:
! 5578: <p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
1.13 cvs 5579: the element with which they are associated. They are not inherited nor
1.18 cvs 5580: transmitted to children elements.</p>
1.30 ! cvs 5581:
! 5582: <p>The background picture has not always the same size as the element's box.
1.13 cvs 5583: There are diffrent ways to fill the element box with the picture. This is
1.18 cvs 5584: specified by the <tt>PictureMode</tt> rule, which should be associated to the
5585: same element. This rule may take one of the following values:</p>
5586: <dl>
1.30 ! cvs 5587: <dt><tt>NormalSize</tt></dt>
! 5588: <dd>The picture is centered in the box, and clipped if it is too
! 5589: large.</dd>
! 5590: <dt><tt>Scale</tt></dt>
! 5591: <dd>The picture is zoomed to fit the box size.</dd>
! 5592: <dt><tt>RepeatX</tt></dt>
! 5593: <dd>The picture is repeated horizontally to fit the box width.</dd>
! 5594: <dt><tt>RepeatY</tt></dt>
! 5595: <dd>The picture is repeated vertically to fit the box height.</dd>
! 5596: <dt><tt>RepeatXY</tt></dt>
! 5597: <dd>The picture is repeated both horizontally and vertically to fill the
! 5598: box.</dd>
1.18 cvs 5599: </dl>
1.30 ! cvs 5600:
! 5601: <p>If an element has a <tt>BackgroundPicture</tt> rule and no
1.18 cvs 5602: <tt>PictureMode</tt> rule, the <tt>NormalSize</tt> value is assumed.</p>
5603: <pre> 'BackgroundPicture' ':' FileName /
1.13 cvs 5604: 'PictureMode' ':' PictMode .
5605:
5606: FileName = STRING .
1.18 cvs 5607: PictMode = 'NormalSize' / 'Scale' / 'RepeatXY' / 'RepeatX' / 'RepeatY' .</pre>
1.30 ! cvs 5608:
! 5609: <p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
1.13 cvs 5610: the element with which they are associated. They are not inherited nor
1.18 cvs 5611: transmitted to children elements.</p>
5612: </div>
1.13 cvs 5613:
1.18 cvs 5614: <div class="subsection">
1.30 ! cvs 5615: <h3><a name="sectc4231">Presentation box content</a></h3>
1.1 cvs 5616:
1.30 ! cvs 5617: <p>The <tt>Content</tt> rule applies to presentation boxes. It indicates the
1.1 cvs 5618: content given to a box. This content is either a variable's value or a
1.18 cvs 5619: constant value. In the special case of <a href="#sectc4233">header or footer
5620: boxes</a>, the content can also be a structured element type.</p>
1.30 ! cvs 5621:
! 5622: <p>If the content is a constant, it can be specified, as in a variable
1.18 cvs 5623: declaration, either by the name of a constant declared in the <tt>CONST</tt>
1.1 cvs 5624: section or by direct specification of the type and value of the box's
1.18 cvs 5625: content.</p>
1.30 ! cvs 5626:
! 5627: <p>Similarly, if it is a variable, the name of a variable declared in
1.18 cvs 5628: <tt>VAR</tt> section can be given or the variable may be defined within
5629: parentheses. The content inside the parentheses has the same syntax as a <a
5630: href="#sectc426">variable declaration</a>.</p>
1.30 ! cvs 5631:
! 5632: <p>When the content is a structured element type, the name of the element type
! 5633: is given after the colon. In this case, the box's content is all elements of
1.1 cvs 5634: the named type which are designated by references which are part of the page
1.18 cvs 5635: on which the header or footer with this <tt>Content</tt> rule appears. Only
5636: associated elements can appear in a <tt>Content</tt> rule and the structure
1.1 cvs 5637: must provide references to these elements. Moreover, the box whose content
5638: they are must be a header or footer box generated by a page box of the primary
1.18 cvs 5639: view.</p>
5640: <pre> 'Content' ':' VarConst
1.1 cvs 5641: VarConst = ConstID / ConstType ConstValue /
5642: VarID / '(' FunctionSeq ')' /
1.18 cvs 5643: ElemID .</pre>
1.30 ! cvs 5644:
! 5645: <p>A presentation box can have only one <tt>Content</tt> rule, which means
! 5646: that the content of a presentation box cannot vary from view to view. However,
! 5647: such an effect can be achieved by creating several presentation boxes, each
! 5648: with different content and visible in different views.</p>
! 5649:
! 5650: <p>The <tt>Content</tt> rule also applies to elements defined as references in
1.1 cvs 5651: the structure schema. In this case, the content defined by the rule must be
5652: a constant. It is this content which appears on the screen or paper to
5653: represent references of the type to which the rule applies. A reference can
1.18 cvs 5654: have a <tt>Content</tt> rule or a <a href="#sectc4234"><tt>Copy</tt> rule</a>
1.1 cvs 5655: for each view. If neither of these rules appears, the reference is displayed
1.18 cvs 5656: as <tt>[*]</tt>, which is equivalent to the rule:</p>
5657: <pre> Content: Text '[*]';</pre>
1.30 ! cvs 5658:
1.18 cvs 5659: <blockquote class="example">
1.30 ! cvs 5660: <p><strong>Example:</strong></p>
! 5661:
! 5662: <p>The content of the presentation box created to make the chapter number
! 5663: and section number appear before each section title can be defined by:</p>
! 5664: <pre>BOXES
1.1 cvs 5665: SectionNumBox :
5666: BEGIN
5667: Content : NumSection;
5668: ...
1.18 cvs 5669: END;</pre>
1.30 ! cvs 5670:
! 5671: <p>if the <tt>NumSection</tt> variable has been defined in the variable
! 5672: definition section of the presentation schema. Otherwise the
! 5673: <tt>Content</tt> would be written:</p>
! 5674: <pre>BOXES
1.1 cvs 5675: SectionNumBox :
5676: BEGIN
5677: Content : (VALUE (ChapterCtr, Roman) TEXT '.'
5678: VALUE (SectionCtr, Arabic));
5679: ...
1.18 cvs 5680: END;</pre>
1.30 ! cvs 5681:
! 5682: <p>To specify that a page footer should contain all elements of the
! 5683: <tt>Note</tt> type are referred to in the page, the following rule is
! 5684: written:</p>
! 5685: <pre>BOXES
1.1 cvs 5686: NotesFooterBox :
5687: BEGIN
5688: Content : Note;
5689: ...
1.18 cvs 5690: END;</pre>
1.30 ! cvs 5691:
! 5692: <p><tt>Note</tt> is defined as an associated element in the structure schema
! 5693: and NotesFooterBox is created by a page box of the primary view.</p>
1.18 cvs 5694: </blockquote>
5695: </div>
1.1 cvs 5696:
1.18 cvs 5697: <div class="subsection">
1.30 ! cvs 5698: <h3><a name="sectc4232">Presentation box creation</a></h3>
1.1 cvs 5699:
1.30 ! cvs 5700: <p>A creation rule specifies that a presentation box should be created when an
1.18 cvs 5701: element of the type to which the rule is attached appears in the document.</p>
1.30 ! cvs 5702:
! 5703: <p>A keyword specifies the position, relative to the creating box, at which
! 5704: the created box will be placed in the structure:</p>
1.18 cvs 5705: <dl>
1.30 ! cvs 5706: <dt><tt>CreateFirst</tt></dt>
! 5707: <dd>specifies that the box should be created as the first box of the next
! 5708: lower level, before any already existing boxes, and only if the
! 5709: beginning of the creating element is visible;</dd>
! 5710: <dt><tt>CreateLast</tt></dt>
! 5711: <dd>specifies that the box should be created as the last box of the next
! 5712: lower level, after any existing boxes, and only if the end of the
! 5713: creating element is visible;</dd>
! 5714: <dt><tt>CreateBefore</tt></dt>
! 5715: <dd>specifies that the box should be created before the creating box, on
! 5716: the same level as the creating box, and only if the beginning of the
! 5717: creating element is visible;</dd>
! 5718: <dt><tt>CreateAfter</tt></dt>
! 5719: <dd>specifies that the box should be created after the creating box, on
! 5720: the same level as the creating box, and only if the beginning of the
! 5721: creating element is visible;</dd>
! 5722: <dt><tt>CreateEnclosing</tt></dt>
! 5723: <dd>specifies that the box should be created at the upper level relatively
! 5724: to the creating box, and that it must contain that creating box and all
! 5725: presentation boxes created by the same creating box.</dd>
1.18 cvs 5726: </dl>
1.30 ! cvs 5727:
! 5728: <p>This keyword can be followed by the <tt>Repeated</tt> keyword to indicate
! 5729: that the box must be created for each part of the creating element. These
! 5730: parts result from the division of the element by page breaks or column
! 5731: changes. If the <tt>Repeated</tt> keyword is missing, the box is only created
! 5732: for the first part of the creating element (<tt>CreateFirst</tt> and
1.18 cvs 5733: <tt>CreateBefore</tt> rules) or for the last part (<tt>CreateLast</tt> and
5734: <tt>CreateAfter</tt> rules).</p>
1.30 ! cvs 5735:
! 5736: <p>The type of presentation to be created is specified at the end of the rule
1.18 cvs 5737: between parentheses.</p>
1.30 ! cvs 5738:
! 5739: <p>Creation rules cannot appear in the <a href="#sectc427">default
! 5740: presentation rules</a>. The boxes being created should have a
! 5741: <tt>Content</tt> rule which indicates their <a
! 5742: href="#sectc4231">content</a>.</p>
! 5743:
! 5744: <p>Creation rules can only appear in the block of rules for the primary view;
1.1 cvs 5745: creation is provoked by a document element for all views. However, for each
5746: view, the presentation box is only created if the creating element is itself a
5747: box in the view. Moreover, the visibility parameter of the presentation box
5748: can be adjusted to control the creation of the box on a view-by-view
1.18 cvs 5749: basis.</p>
5750: <pre> Creation '(' BoxID ')'
1.1 cvs 5751: Creation = Create [ 'Repeated' ] .
5752: Create ='CreateFirst' / 'CreateLast' /
5753: 'CreateBefore' / 'CreateAfter' /
1.18 cvs 5754: 'CreateEnclosing' .</pre>
1.30 ! cvs 5755:
1.18 cvs 5756: <blockquote class="example">
1.30 ! cvs 5757: <p><strong>Example:</strong></p>
! 5758:
! 5759: <p>Let us define an object type, called Table, which is composed of a
! 5760: sequence of columns, all having the same fixed width, where the columns are
! 5761: separated by vertical lines. There is a line to the left of the first
! 5762: column and one to the right of the last. Each column has a variable number
! 5763: of cells, placed one on top of the other and separated by horizontal lines.
! 5764: There are no horizontal lines above the first cell or below the last cell.
! 5765: The text contained in each cell is broken into lines and these lines are
! 5766: centered horizontally in the cell. The logical structure of this object is
! 5767: defined by:</p>
! 5768: <pre>Table = LIST OF (Column);
1.18 cvs 5769: Column = LIST OF (Cell = Text);</pre>
5770:
1.30 ! cvs 5771: <div class="figure">
! 5772: <hr>
! 5773: <pre>| | | |
1.1 cvs 5774: | xx xxxx xxxx |x xxxx xxx xxxxx| x xxx x xxx |
5775: | xxx xxx xxxx x | x xx x xxx | xxxxx xxxx xx |
5776: | xxxxx xxxx |----------------| xxx xxxxx x |
5777: | xxxxx xxx xxxx | xxxx xx xx xxx | xx xx |
5778: | xxx xxxx x xxx | xxxx x xxx x |---------------|
5779: |----------------| xxx xxxx xxxxx | xxxxx xxxxx |
5780: | xxx xxx xxxxxx |----------------| xxx xxxx xxxx |
5781: | xxxx xxxx xx | xxxx xx x xx | xxx xx x xx |
5782: |----------------| xxx xxxxx xxxx | xxxx xxxx xxx |
5783: | xxxxx xxx xxxx | xxxx xx x xx | xxxxx xxx |
1.18 cvs 5784: |xxxx xx x xxxxxx| xxxx xx xxxxxx | xxxxx xxxxx |</pre>
1.19 cvs 5785:
1.30 ! cvs 5786: <p align="center"><em><a name="table">The design of a table</a></em></p>
! 5787: <hr>
! 5788: </div>
! 5789:
! 5790: <p>The presentation of the table should resemble the design of the above <a
! 5791: href="#table">figure</a>. It is defined by the following presentation
! 5792: schema fragment:</p>
! 5793: <pre>BOXES
1.1 cvs 5794: VertLine : BEGIN
5795: Width : 0.3 cm;
5796: Height : Enclosing . Height;
5797: VertPos : Top = Enclosing . Top;
5798: HorizPos : Left = Previous . Right;
5799: Content : Graphics 'v';
5800: END;
5801:
5802: HorizLine: BEGIN
5803: Width : Enclosing . Width;
5804: Height : 0.3 cm;
5805: VertPos : Top = Previous . Bottom;
5806: HorizPos : Left = Enclosing . Left;
5807: Content : Graphics 'h';
5808: END;
5809:
5810: RULES
1.6 cvs 5811: Column : BEGIN
5812: CreateBefore (VertLine);
5813: IF LAST CreateAfter (VertLine);
5814: Width : 2.8 cm;
5815: Height : Enclosed . Height;
5816: VertPos : Top = Enclosing . Top;
5817: HorizPos : Left = Previous . Right;
5818: END;
5819:
5820: Cell : BEGIN
5821: IF NOT FIRST CreateBefore (HorizLine);
5822: Width : Enclosing . Width;
5823: Height : Enclosed . Height;
5824: VertPos : Top = Previous . Bottom;
5825: HorizPos : Left = Enclosing . Left;
5826: Line;
5827: Adjust : VMiddle;
1.18 cvs 5828: END;</pre>
1.30 ! cvs 5829:
! 5830: <p>It is useful to note that the horizontal position rule of the first
! 5831: vertical line will not be applied, since there is no preceding box. In this
! 5832: case, the box is simply placed on the left side of the enclosing box.</p>
1.18 cvs 5833: </blockquote>
5834: </div>
5835:
5836: <div class="subsection">
1.30 ! cvs 5837: <h3><a name="sectc4233">Page layout</a></h3>
1.18 cvs 5838:
1.30 ! cvs 5839: <p>The page models specified in the <tt>Page</tt> rule are defined by boxes
1.18 cvs 5840: declared in the <tt>BOXES</tt> section of the presentation schema. Pages are
1.1 cvs 5841: not described as frames which will be filled by the document's text, but as
5842: element are inserted in the flow of the document and which mark the page
5843: breaks. Each of these page break elements contains presentation boxes which
5844: represent the footer boxes of a page followed by header boxes of the next
5845: page. The page box itself is the simple line which separates two pages on the
5846: screen. Both the footer and header boxes placed themselves with respect to
5847: this page box, with the footer being placed above it and the header boxes
1.18 cvs 5848: being placed above it.</p>
1.30 ! cvs 5849:
! 5850: <p>The boxes created by a page box are headers and footers and can only place
1.1 cvs 5851: themselves vertically with respect to the page box itself (which is in fact
5852: the separation between two pages). Besides, it is their vertical position
5853: rule which determines whether they are header or footer boxes. Header and
5854: footer boxes must have an explicit vertical position rule (they must not use
1.18 cvs 5855: the default rule).</p>
1.30 ! cvs 5856:
! 5857: <p>Footer boxes must have an absolute height or inherit the height of their
1.18 cvs 5858: contents:</p>
5859: <pre>Height : Enclosed . Height;</pre>
1.30 ! cvs 5860:
! 5861: <p>A page box must have height and width rules and these two rules must be
1.1 cvs 5862: specified with constant values, expressed in centimeters, inches, or
5863: typographer's points. These two rules are interpreted in a special way for
5864: page boxes: they determine the width of the page and the vertical distance
5865: between two page separators, which is the height of the page and its header
1.18 cvs 5866: and footer together.</p>
1.30 ! cvs 5867:
! 5868: <p>A page box should also have vertical and horizontal position rules and
! 5869: these two rules should specify the position on the sheet of paper of the
! 5870: rectangle enclosing the page's contents. These two rules must position the
! 5871: upper left corner of the enclosing rectangle in relation to the upper left
! 5872: corner of the sheet of paper, considered to be the enclosing element. In both
! 5873: rules, distances must be expressed in fixed units: centimeters (<tt>cm</tt>),
! 5874: inches (<tt>in</tt>), or typographer's points (<tt>pt</tt>). Thus, rules
! 5875: similar to the following should be found in the rules for a page box:</p>
1.18 cvs 5876: <pre>BOXES
1.1 cvs 5877: ThePage :
5878: BEGIN
5879: VertPos : Top = Enclosing . Top + 3 cm;
5880: HorizPos : Left = Enclosing . Left + 2.5 cm;
5881: Width : 16 cm;
5882: Height : 22.5 cm;
1.18 cvs 5883: END;</pre>
1.30 ! cvs 5884:
! 5885: <p>When a document must be page broken, the page models to be constructed are
1.18 cvs 5886: defined in the <tt>BOXES</tt> section of the presentation schema by declaring
5887: page boxes and header and footer boxes. Also, the <tt>Page</tt> rule is used
1.1 cvs 5888: to specify to which parts of the document and to which views each model should
1.18 cvs 5889: be applied.</p>
1.30 ! cvs 5890:
! 5891: <p>The <tt>Page</tt> rule has only one parameter, given between parentheses
! 5892: after the <tt>Page</tt> keyword. This parameter is the name of the box which
! 5893: must serve as the model for page construction. When a <tt>Page</tt> rule is
1.1 cvs 5894: attached to an element type, each time such an element appears in a document,
5895: a page break takes place and the page model indicated in the rule is applied
5896: to all following pages, until reaching the next element which has a
1.18 cvs 5897: <tt>Page</tt> rule.</p>
1.30 ! cvs 5898:
! 5899: <p>The <tt>Page</tt> rule applies to only one view; if it appears in the
! 5900: primary view's block of rules, a <tt>Page</tt> rule applies only to that view.
! 5901: Thus, different page models can be defined for the full document and for its
! 5902: table of contents, which is another view of the same document. Some views can
! 5903: be specified with pages, and other views of the same document can be specified
1.18 cvs 5904: without pages.</p>
5905: <pre> 'Page' '(' BoxID ')'</pre>
5906: </div>
5907:
5908: <div class="subsection">
1.30 ! cvs 5909: <h3><a name="sectc4234">Box copies</a></h3>
1.18 cvs 5910:
1.30 ! cvs 5911: <p>The <tt>Copy</tt> rule can be used for an element which is defined as a
1.7 cvs 5912: reference in the structure schema. In this case, the rule specifies, between
1.18 cvs 5913: parenthesis, the name of the box (declared in the <tt>BOXES</tt> section)
1.1 cvs 5914: which must be produced when this reference appears in the structure of a
5915: document. The box produced is a copy (same contents, but possible different
5916: presentation) of the box type indicated by the parameter between parentheses,
5917: and which is in the element designated by the reference. The name of a box
5918: can be replaced by type name. Then what is copied is the contents of the
1.18 cvs 5919: element of this type which is inside the referenced element.</p>
1.30 ! cvs 5920:
! 5921: <p>Whether a box name or type name is given, it may be followed by the name of
! 5922: a structure schema between parentheses. This signifies that the box or type
! 5923: is defined in the indicated structure schema and not in the structure schema
! 5924: with which the rule's presentation schema is associated.</p>
! 5925:
! 5926: <p>The <tt>Copy</tt> rule can also be applied to a presentation box. If the
1.1 cvs 5927: presentation box was created by a reference attribute, the rule is applied as
5928: in the case of a reference element: the contents of the box having the
1.18 cvs 5929: <tt>Copy</tt> rule are based on the element designated by the reference
5930: attribute. For other presentation boxes, the <tt>Copy</tt> rule takes a type
1.1 cvs 5931: name parameter which can be followed, between parentheses, by the name of the
5932: structure schema in which the type is defined, if it is not defined in the
5933: same schema. The contents of the box which has this rule are a copy of the
5934: element of this type which is in the element creating the presentation box, or
5935: by default, the box of this type which precedes the presentation box. This
5936: last facility is used, for example, to define the running titles in headers or
1.18 cvs 5937: footers.</p>
5938: <pre> 'Copy' '(' BoxTypeToCopy ')' .
1.1 cvs 5939: BoxTypeToCopy = BoxID [ ExtStruct ] /
1.6 cvs 5940: ElemID [ ExtStruct ] .
1.18 cvs 5941: ExtStruct = '(' ElemID ')' .</pre>
1.30 ! cvs 5942:
! 5943: <p>Like the creation rules, the <tt>Copy</tt> rule cannot appear in the <a
1.18 cvs 5944: href="#sectc427">default presentation rules</a>. Moreover, this rule can only
5945: appear in the primary view's block of rules; the copy rule is applied to all
5946: views.</p>
1.30 ! cvs 5947:
1.18 cvs 5948: <blockquote class="example">
1.30 ! cvs 5949: <p><strong>Example:</strong></p>
! 5950:
! 5951: <p>If the following definitions are in the structure schema:</p>
! 5952: <pre>Body = LIST OF (Chapter =
1.1 cvs 5953: BEGIN
5954: ChapterTitle = Text;
5955: ChapterBody = SectionSeq;
5956: END);
1.18 cvs 5957: RefChapter = REFERENCE (Chapter);</pre>
1.30 ! cvs 5958:
! 5959: <p>then the following presentation rules (among many other rules in the
! 5960: presentation schema) can be specified:</p>
! 5961: <pre>COUNTERS
1.1 cvs 5962: ChapterCtr : RANK OF Chapter;
5963: BOXES
5964: ChapterNumber :
5965: BEGIN
5966: Content : (VALUE (ChapterCtr, URoman));
5967: ...
5968: END;
5969: RULES
5970: Chapter :
5971: BEGIN
5972: CreateFirst (ChapterNumber);
5973: ...
5974: END;
5975: RefChapter :
5976: BEGIN
5977: Copy (ChapterNumber);
5978: ...
1.18 cvs 5979: END;</pre>
1.30 ! cvs 5980:
! 5981: <p>which makes the number of the chapter designated by the reference appear
! 5982: in uppercase roman numerals, in place of the reference to a chapter itself.
! 5983: Alternatively, the chapter title can be made to appear in place of the
! 5984: reference by writing this <tt>Copy</tt>rule:</p>
! 5985: <pre> Copy (ChapterTitle);</pre>
! 5986:
! 5987: <p>To define a header box, named <tt>RunningTitle</tt>, which contains the
! 5988: title of the current chapter, the box's contents are defined in this
! 5989: way:</p>
! 5990: <pre>BOXES
1.1 cvs 5991: RunningTitle :
1.18 cvs 5992: Copy (ChapterTitle);</pre>
5993: </blockquote>
5994: </div>
5995: </div>
5996: <hr>
5997: </div>
1.1 cvs 5998:
1.18 cvs 5999: <div class="chapter">
6000: <h1><a name="sect5">The T language</a></h1>
1.1 cvs 6001:
1.18 cvs 6002: <div class="section">
1.30 ! cvs 6003: <h2><a name="sectb51">Document translation</a></h2>
1.1 cvs 6004:
1.30 ! cvs 6005: <p>Because of its document model, Thot can produce documents in a high-level
1.18 cvs 6006: abstract form. This form, called the <em>canonical form</em> is specific to
1.1 cvs 6007: Thot; it is well suited to the editor's manipulations, but it does not
6008: necessarily suit other operations which might be applied to documents. Because
6009: of this, the Thot editor offers the choice of saving documents in its own form
6010: (the canonical form) or a format defined by the user. In the latter case, the
6011: Thot document is transformed by the translation program. This facility can
6012: also be used to export documents from Thot to systems using other
1.18 cvs 6013: formalisms.</p>
1.1 cvs 6014:
1.18 cvs 6015: <div class="subsection">
1.30 ! cvs 6016: <h3><a name="sectc511">Translation principles</a></h3>
1.1 cvs 6017:
1.30 ! cvs 6018: <p>Document translation allows the export of documents to other systems which
! 6019: do not accept Thot's canonical form. Translation can be used to export
! 6020: document to source-based formatters like T<sub><big>E</big></sub>X,
1.18 cvs 6021: L<sup>A</sup>T<sub><big>E</big></sub>X, and <tt>troff</tt>. It can also be
1.1 cvs 6022: used to translate documents into interchange formats like SGML or HTML. To
6023: allow the widest range of possible exports, Thot does not limit the choice of
6024: translations, but rather allows the user to define the formalisms into which
1.18 cvs 6025: documents can be translated.</p>
1.30 ! cvs 6026:
! 6027: <p>For each document or object class, a set of translation rules can be
! 6028: defined, specifying how the canonical form should be transformed into a given
1.18 cvs 6029: formalism. These translation rules are grouped into <em>translation
6030: schemas</em>, each schema containing the rules necessary to translate a
1.1 cvs 6031: generic logical structure (document or object structure) into a particular
6032: formalism. The same generic logical structure can have several different
6033: translation schemas, each defining translation rules for a different
1.18 cvs 6034: formalism.</p>
1.30 ! cvs 6035:
! 6036: <p>Like presentation schemas, translation schemas are generic. Thus, they
! 6037: apply to an entire object or document class and permit translation of all
! 6038: documents or objects of that class.</p>
1.18 cvs 6039: </div>
1.1 cvs 6040:
1.18 cvs 6041: <div class="subsection">
1.30 ! cvs 6042: <h3><a name="sectc512">Translation procedure</a></h3>
1.1 cvs 6043:
1.30 ! cvs 6044: <p>The translator works on the specific logical structure of the document
! 6045: being translated. It traverses the primary tree of this logical structure in
1.1 cvs 6046: pre-order and, at each node encountered, it applies the corresponding
6047: translation rules defined in the translation schema. Translation can be
1.18 cvs 6048: associated:</p>
6049: <ul>
1.30 ! cvs 6050: <li>with element types defined in the structure schema,</li>
! 6051: <li>with global or local attributes defined in the structure schema,</li>
! 6052: <li>with specific presentation rules,</li>
! 6053: <li>with the content of the leaves of the structure (characters, symbols
! 6054: and graphical elements)</li>
1.18 cvs 6055: </ul>
1.30 ! cvs 6056:
! 6057: <p>Thus, for each node, the translator applies all rules associated with the
1.1 cvs 6058: element type, all rules associated with each attribute (local or global)
6059: carried by the element, and if the element is a leaf of the tree, it also
1.10 cvs 6060: applies translation rules for characters, symbols, or graphical elements,
1.18 cvs 6061: depending on the type of the leaf.</p>
1.30 ! cvs 6062:
! 6063: <p>Rules associated with the content of leaves are different from all other
1.1 cvs 6064: rules: they specify only how to translate character strings, symbols, and
6065: graphical elements. All other rules, whether associated with element types,
6066: with specific presentation rules or with attributes, are treated similarly.
1.18 cvs 6067: These rules primarily allow:</p>
6068: <ul>
1.30 ! cvs 6069: <li>generation of a text constant or variable before or after the contents
! 6070: of an element,</li>
! 6071: <li>modification of the order in which elements appear after
! 6072: translation,</li>
! 6073: <li>removal of an element in the translated document,</li>
! 6074: <li>and writing messages on the user's terminal during translation.</li>
1.18 cvs 6075: </ul>
6076: </div>
6077: </div>
1.1 cvs 6078:
1.18 cvs 6079: <div class="section">
1.30 ! cvs 6080: <h2><a name="sectb52">Translation definition language</a></h2>
1.1 cvs 6081:
1.30 ! cvs 6082: <p>Translation schemas are written in a custom language, called T, which is
1.1 cvs 6083: described in the rest of this chapter. The grammar of T is specified using
1.18 cvs 6084: the same <a href="#sectc321">meta-language</a> as was used for the S and P
1.1 cvs 6085: languages and the translation schemas are written using the same conventions
6086: as the structure and presentation schemas. In particular, the keywords of the
6087: T language (the stings between apostrophes in the following syntax rules) can
6088: be written in any combination of upper-case and lower-case letters, but
6089: identifiers created by the programmer must always be written in the same
1.18 cvs 6090: way.</p>
1.1 cvs 6091:
1.18 cvs 6092: <div class="subsection">
1.30 ! cvs 6093: <h3><a name="sectc521">Organization of a translation schema</a></h3>
1.1 cvs 6094:
1.30 ! cvs 6095: <p>A translation schema is begun by the <tt>TRANSLATION</tt> keyword and is
1.18 cvs 6096: terminated by the <tt>END</tt> keyword. The <tt>TRANSLATION</tt> keyword is
1.1 cvs 6097: followed by the name of the generic structure for which a translation is being
6098: defined and a semicolon. This name must be identical to the name which
1.18 cvs 6099: appears after the <tt>STRUCTURE</tt> keyword in the corresponding structure
6100: schema.</p>
1.30 ! cvs 6101:
! 6102: <p>After this declaration of the structure, the following material appears in
1.18 cvs 6103: order:</p>
6104: <ul>
1.30 ! cvs 6105: <li>the length of lines produced by the translation,</li>
! 6106: <li>the character delimiting the end of the line,</li>
! 6107: <li>the character string which the translator will insert if it must
! 6108: line-break the translated text,</li>
! 6109: <li>declarations of
! 6110: <ul>
! 6111: <li>buffers,</li>
! 6112: <li>counters,</li>
! 6113: <li>constants,</li>
! 6114: <li>variables,</li>
! 6115: </ul>
! 6116: </li>
! 6117: <li>translation rules associated with element types,</li>
! 6118: <li>translation rules associated with attributes,</li>
! 6119: <li>translation rules associated with specific presentation rules,</li>
! 6120: <li>translation rules associated with characters strings, symbols and
! 6121: graphical elements.</li>
1.18 cvs 6122: </ul>
1.30 ! cvs 6123:
! 6124: <p>Each of these sections is introduced by a keyword followed by a sequence of
1.1 cvs 6125: declarations. All of these sections are optional, expect for the translation
1.18 cvs 6126: rules associated with element types. Many <tt>TEXTTRANSLATE</tt> sections can
1.1 cvs 6127: appear, each defining the rules for translating character strings of a
1.18 cvs 6128: particular alphabet.</p>
6129: <pre> TransSchema ='TRANSLATION' ElemID ';'
1.1 cvs 6130: [ 'LINELENGTH' LineLength ';' ]
6131: [ 'LINEEND' CHARACTER ';' ]
6132: [ 'LINEENDINSERT' STRING ';' ]
6133: [ 'BUFFERS' BufferSeq ]
6134: [ 'COUNTERS' CounterSeq ]
6135: [ 'CONST' ConstSeq ]
6136: [ 'VAR' VariableSeq ]
6137: 'RULES' ElemSeq
6138: [ 'ATTRIBUTES' AttrSeq ]
6139: [ 'PRESENTATION' PresSeq ]
1.30 ! cvs 6140: < 'TEXTTRANSLATE' TextTransSeq >
1.1 cvs 6141: [ 'SYMBTRANSLATE' TransSeq ]
6142: [ 'GRAPHTRANSLATE' TransSeq ]
1.18 cvs 6143: 'END' .</pre>
6144: </div>
1.1 cvs 6145:
1.18 cvs 6146: <div class="subsection">
1.30 ! cvs 6147: <h3><a name="sectc522">Line length</a></h3>
1.1 cvs 6148:
1.30 ! cvs 6149: <p>If a <tt>LINELENGTH</tt> instruction is present after the structure
1.1 cvs 6150: declaration, the translator divides the text it produces into lines, each line
6151: having a length less than or equal to the integer which follows the
1.18 cvs 6152: <tt>LINELENGTH</tt> keyword. This maximum line length is expressed as a
1.1 cvs 6153: number of characters. The end of the line is marked by the character defined
1.18 cvs 6154: by the <tt>LINEEND</tt> instruction. When the translator breaks the lines on
1.1 cvs 6155: a space character in generated text, this space will be replaced by the
1.18 cvs 6156: character string defined by the <tt>LINEENDINSERT</tt> instruction.</p>
1.30 ! cvs 6157:
! 6158: <p>If the <tt>LINEEND</tt> instruction is not defined then the linefeed
! 6159: character (octal code 12) is used as the default line end character. If the
1.18 cvs 6160: <tt>LINEENDINSERT</tt> instruction is not defined, the linefeed character is
6161: inserted at the end of the produced lines. If there is no <tt>LINELENGTH</tt>
1.1 cvs 6162: instruction, the translated text is not divided into lines. Otherwise, if the
6163: translation rules generate line end marks, these marks remain in the
6164: translated text, but the length of the lines is not controlled by the
1.18 cvs 6165: translator.</p>
6166: <pre> LineLength = NUMBER .</pre>
1.30 ! cvs 6167:
1.18 cvs 6168: <blockquote class="example">
1.30 ! cvs 6169: <p><strong>Example:</strong></p>
! 6170:
! 6171: <p>To limit the lines produced by the translator to a length of 80
! 6172: characters, the following rule is written at the beginning of the
! 6173: translation schema.</p>
! 6174: <pre>LineLength 80;</pre>
1.18 cvs 6175: </blockquote>
6176: </div>
1.1 cvs 6177:
1.18 cvs 6178: <div class="subsection">
1.30 ! cvs 6179: <h3><a name="sectc523">Buffers</a></h3>
1.1 cvs 6180:
1.30 ! cvs 6181: <p>A buffer is a unit of memory managed by the translator, which can either
1.18 cvs 6182: contain text read from the terminal during the translation (see the <a
6183: href="#sectc5212"><tt>Read</tt> rule</a>), or the name of the last picture
1.1 cvs 6184: (bit-map) encountered by the translator in its traversal of the document.
1.2 cvs 6185: Remember the pictures are stored in files that are separate for the document
1.1 cvs 6186: files and that the canonical form contains only the names of the files in
1.18 cvs 6187: which the pictures are found.</p>
1.30 ! cvs 6188:
! 6189: <p>Thus, there are two types of buffers: buffers for reading from the
! 6190: terminal (filled by the <tt>Read</tt> rule) and the buffer of picture names
! 6191: (containing the name of the last picture encountered). A translation schema
! 6192: can use either type, one or several read buffers and one (and only one)
! 6193: picture name buffer.</p>
! 6194:
! 6195: <p>If any buffers are used, the <tt>BUFFERS</tt> keyword must be present,
1.1 cvs 6196: followed by declarations of every buffer used in the translation schema. Each
6197: buffer declaration is composed only of the name of the buffer, chosen freely
1.2 cvs 6198: by the programmer. The picture name buffer is identified by the
1.18 cvs 6199: <tt>Picture</tt> keyword, between parentheses, following the buffer name. The
6200: <tt>Picture</tt> keyword may only appear once. Each buffer declaration is
6201: terminated by a semicolon.</p>
1.30 ! cvs 6202: <pre> BufferSeq = Buffer < Buffer > .
1.1 cvs 6203: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
1.18 cvs 6204: BufferID = NAME .</pre>
1.30 ! cvs 6205:
1.18 cvs 6206: <blockquote class="example">
1.30 ! cvs 6207: <p><strong>Example:</strong></p>
! 6208:
! 6209: <p>The following buffer declarations create a picture name buffer named
! 6210: <tt>pictureName</tt> and a read buffer named <a
! 6211: name="destname"><tt>DestName</tt></a>:</p>
! 6212: <pre>BUFFERS
1.18 cvs 6213: pictureName (Picture); DestName;</pre>
6214: </blockquote>
6215: </div>
1.1 cvs 6216:
1.18 cvs 6217: <div class="subsection">
1.30 ! cvs 6218: <h3><a name="sectc524">Counters</a></h3>
! 6219:
! 6220: <p>Certain translation rules generate text that varies according to the
! 6221: context of the element to which the rules apply. Variable text is defined
! 6222: either in the <a href="#sectc526"><tt>VAR</tt> section</a> of the translation
! 6223: schema or in the rule itself (see the <tt>Create</tt> and <tt>Write</tt>
! 6224: rules). Both types of definition rely on counters for the calculation of
! 6225: variable material.</p>
! 6226:
! 6227: <p>There are two types of counter: counters whose value is explicitely
! 6228: computed by applying <a href="#sectc5221"><tt>Set</tt> and <tt>Add</tt>
! 6229: rules</a>, and counters whose value is computed by a function associated with
! 6230: the counter. Those functions allow the same calculations as can be used in
! 6231: presentation schemas. As in a presentation schema, counters must be defined in
! 6232: the <tt>COUNTERS</tt> section of the translation schema before they are
! 6233: used.</p>
! 6234:
! 6235: <p>When counters are used in a translation schema, the <tt>COUNTERS</tt>
! 6236: keyword is followed by the declarations of every counter used. Each
! 6237: declaration is composed of the counter's name possibly followed by a colon and
! 6238: the counting function to be used for the counter. The declaration is
! 6239: terminated by a semi-colon. If the counter is explicitely computed by
! 6240: <tt>Set</tt> and <tt>Add</tt> rules, no counting function is indicated. If a
! 6241: counting function is indicated, <tt>Set</tt> and <tt>Add</tt> rules cannot be
! 6242: applied to that counter.</p>
1.1 cvs 6243:
1.30 ! cvs 6244: <p>The counting function indicates how the counter's value will be computed.
1.18 cvs 6245: Three functions are available: <tt>Rank</tt>, <tt>Rlevel</tt>, and
6246: <tt>Set</tt>.</p>
6247: <ul>
1.30 ! cvs 6248: <li><tt>Rank of ElemID</tt> indicates that the counter's value is the rank
! 6249: of the element of type <tt>ElemID</tt> which encloses the element for
! 6250: which the counter is being evaluated. For the purposes of this function,
! 6251: an element of type <tt>ElemID</tt> is considered to enclose itself. This
! 6252: function is primarily used when the element of type <tt>ElemID</tt> is
! 6253: part of an aggregate or list, in which case the counter's value is the
! 6254: element's rank in its list or aggregate. Note that, unlike the
! 6255: <tt>Rank</tt> function for presentation schemas, the <tt>Page</tt> keyword
! 6256: cannot be used in place of the <tt>ElemID</tt>.
! 6257: <p>The type name <tt>ElemID</tt> can be followed by an integer. That
! 6258: number represents the relative level, among the ancestors of the concerned
! 6259: element, of the element whose rank is asked. If that relative level
! 6260: <i>n</i> is unsigned, the <i>n<sup>th</sup></i> element of type
! 6261: <tt>ElemID</tt> encountered when travelling the logical structure from the
! 6262: root to the concerned element is taken into account. If the relative
! 6263: level is negative, the logical structure is travelled in the other
! 6264: direction, from the concerned element to the root.</p>
! 6265: </li>
! 6266: <li><tt>Rlevel of ElemID</tt> indicates that the counter's values is the
! 6267: relative level in the tree of the element for which the counter is being
! 6268: evaluated. The counter counts the number of elements of type
! 6269: <tt>ElemID</tt> which are found on the path between the root of the
! 6270: document's logical structure tree and the element (inclusive).</li>
! 6271: <li><tt>Set n on Type1 Add m on Type2</tt> indicates that the counter's
! 6272: value is calculated as follows: in traversing the document from the
! 6273: beginning to the element for which the counter is being evaluated, the
! 6274: counter is set to the value <tt>n</tt> each time a <tt>Type1</tt> element
! 6275: is encountered and is incremented by the amount <tt>m</tt> each time a
! 6276: <tt>Type2</tt> element is encountered. The initial value <tt>n</tt> and
! 6277: the increment <tt>m</tt> are integers.</li>
! 6278: </ul>
! 6279:
! 6280: <p>As in a presentation schema, the <tt>Rank</tt> and <tt>Set</tt> functions
! 6281: can be modified by a numeric attribute which changes their initial value. This
! 6282: is indicated by the <tt>Init</tt> keyword followed by the numeric attribute's
1.18 cvs 6283: name. The <tt>Set</tt> function takes the value of the attribute instead of
6284: the <tt>InitValue</tt> (<tt>n</tt>). For the <tt>Rank</tt> function, the
1.1 cvs 6285: value of the attribute is considered to be the rank of the first element of
6286: the list (rather than the normal value of 1). Subsequent items in the list
6287: have their ranks shifted accordingly. In both cases, the attribute must be
1.18 cvs 6288: numeric and must be a local attribute of the root of the document itself.</p>
1.30 ! cvs 6289: <pre> CounterSeq = Counter < Counter > .
1.1 cvs 6290: Counter = CounterID [ ':' CounterFunc ] ';' .
6291: CounterID = NAME .
6292: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
6293: [ 'Init' AttrID ] /
6294: 'Rlevel' 'of' ElemID /
6295: 'Set' InitValue 'On' ElemID
6296: 'Add' Increment 'On' ElemID
6297: [ 'Init' AttrID ] .
6298: SLevelAsc = [ '-' ] LevelAsc .
6299: LevelAsc = NUMBER .
6300: InitValue = NUMBER .
6301: Increment = NUMBER .
6302: ElemID = NAME .
1.18 cvs 6303: AttrID = NAME .</pre>
1.30 ! cvs 6304:
1.18 cvs 6305: <blockquote class="example">
1.30 ! cvs 6306: <p><strong>Example:</strong></p>
! 6307:
! 6308: <p>If the body of a chapter is defined in the structure schema by:</p>
! 6309: <pre>Chapter_Body = LIST OF
1.1 cvs 6310: (Section = BEGIN
6311: Section_Title = Text;
6312: Section_Body = BEGIN
6313: Paragraphs;
6314: Section;
6315: END;
6316: END
1.18 cvs 6317: );</pre>
1.30 ! cvs 6318:
! 6319: <p>(sections are defined recursively), a counter can be defined giving the
! 6320: <a name="sectnum">number of a section</a> within its level in the
! 6321: hierarchy:</p>
! 6322: <pre>COUNTERS
1.18 cvs 6323: SectionNumber : Rank of Section;</pre>
1.30 ! cvs 6324:
! 6325: <p>A counter holding the hierarchic level of a section:</p>
! 6326: <pre> SectionLevel : Rlevel of Section;</pre>
! 6327:
! 6328: <p>A <a name="uniquenum">counter</a> which sequentially numbers all the
! 6329: document's sections, whatever their hierarchic level:</p>
! 6330: <pre> UniqueSectNum : Set 0 on Document Add 1 on Section;</pre>
1.18 cvs 6331: </blockquote>
6332: </div>
1.1 cvs 6333:
1.18 cvs 6334: <div class="subsection">
1.30 ! cvs 6335: <h3><a name="sectc525">Constants</a></h3>
1.1 cvs 6336:
1.30 ! cvs 6337: <p>A common feature of translation rules is the generation of constant text.
! 6338: This text can be defined in the rule that generates it (see for example the <a
1.18 cvs 6339: href="#sectc5210"><tt>Create</tt></a> and <a
6340: href="#sectc5211"><tt>Write</tt></a> rules); but it can also be defined once
6341: in the constant declaration section and used many times in different rules.
6342: The latter option is preferable when the same text is used in several rules or
6343: several <a href="#sectc526">variables</a>.</p>
1.30 ! cvs 6344:
! 6345: <p>The <tt>CONST</tt> keyword begins the constant declaration section of the
1.1 cvs 6346: translation schema. It must be omitted if no constants are declared. Each
6347: constant declaration is composed of the constant name, an equals sign, and the
6348: constant's value, which is a character string between apostrophes. A constant
1.18 cvs 6349: declaration is terminated by a semicolon.</p>
1.30 ! cvs 6350: <pre> ConstSeq = Const < Const > .
1.1 cvs 6351: Const = ConstID '=' ConstValue ';' .
6352: ConstID = NAME .
1.18 cvs 6353: ConstValue = STRING .</pre>
1.30 ! cvs 6354:
1.18 cvs 6355: <blockquote class="example">
1.30 ! cvs 6356: <p><strong><a name="levelexample">Example:</a></strong></p>
! 6357:
! 6358: <p>The following rule assigns the name <tt>TxtLevel</tt> to the character
! 6359: string ``Level'':</p>
! 6360: <pre>CONST
1.18 cvs 6361: TxtLevel = 'Level';</pre>
6362: </blockquote>
6363: </div>
1.1 cvs 6364:
1.18 cvs 6365: <div class="subsection">
1.30 ! cvs 6366: <h3><a name="sectc526">Variables</a></h3>
1.1 cvs 6367:
1.30 ! cvs 6368: <p>Variables allow to define variable text which is generated by the
1.18 cvs 6369: <tt>Create</tt> and <tt>Write</tt> rules. They are also used to define file
6370: names which are used in the <tt>Create</tt>, <tt>ChangeMainFile</tt>,
6371: <tt>RemoveFile</tt>, and <tt>Indent</tt> rules. Variables can be defined
6372: either in the <tt>VAR</tt> section of the translation schema or directly in
6373: the rules which use them. Variables that define file names must be declared
6374: in the <tt>VAR</tt> section, and when the same variable is used several times
6375: in the translation schema, it makes sense to define it globally in the
6376: <tt>VAR</tt> section. This section is only present if at least one variable
6377: is defined globally.</p>
1.30 ! cvs 6378:
! 6379: <p>After the <tt>VAR</tt> keyword, each global variable is defined by its
! 6380: name, a colon separator and a sequence of functions (at least one function).
! 6381: Each variable definition is terminated by a semicolon. Functions determine the
1.1 cvs 6382: different parts which together give the value of the variable. The value is
6383: obtained by concatenating the strings produced by each of the functions. Seven
6384: types of functions are available. Each variable definition may use any number
1.18 cvs 6385: of functions of each type.</p>
6386: <ul>
1.30 ! cvs 6387: <li>The function <tt>Value(Counter)</tt>returns a string representing the
! 6388: value taken by the counter when it is evaluated for the element in whose
! 6389: rule the variable is used. The counter must have been declared in the
! 6390: <tt>COUNTERS</tt> section of the translation schema. When the counter is
! 6391: expressed in arabic numerals, the counter name can be followed by a colon
! 6392: and an integer indicating a minimum length (number of characters) for the
! 6393: string; if the counter's value is normally expressed with fewer characters
! 6394: than the required minimum, zeroes are added to the front of the string to
! 6395: achieve the minimum length.
! 6396: <p>By default, the counter value is written in arabic digits. If another
! 6397: representation of that value is needed, the counter name must be followed
! 6398: by a comma and one of the following keywords:</p>
! 6399: <ul>
! 6400: <li><tt>Arabic</tt>: arabic numerals (default value),</li>
! 6401: <li><tt>LRoman</tt>: lower-case roman numerals,</li>
! 6402: <li><tt>URoman</tt>: upper-case roman numerals,</li>
! 6403: <li><tt>Uppercase</tt>: upper-case letter,</li>
! 6404: <li><tt>Lowercase</tt>: lower-case letter.</li>
! 6405: </ul>
! 6406: </li>
! 6407: <li>The function <tt>FileDir</tt>, without parameter, returns a string
! 6408: representing the name of the directory of the output file that has been
! 6409: given as a parameter to the translation program. The string includes a
! 6410: character '/' at the end.</li>
! 6411: <li>The function <tt>FileName</tt>, without parameter, returns a string
! 6412: representing the name of the output file that has been given as a
! 6413: parameter to the translation program. The file extension (the character
! 6414: string that terminate the file name, after a dot) is not part of that
! 6415: string.</li>
! 6416: <li>The function <tt>Extension</tt>, without parameter, returns a string
! 6417: representing the extension of the file name. That string is empty if the
! 6418: file name that has been given as a parameter to the translation program
! 6419: has no extension. If there is an extension, its first character is a
! 6420: dot.</li>
! 6421: <li>The function <tt>DocumentName</tt>, without parameter, returns a string
! 6422: representing the name of the document being translated.</li>
! 6423: <li>The function <tt>DocumentDir</tt>, without parameter, returns a string
! 6424: representing the directory containing the document being translated.</li>
! 6425: <li>The function formed by the name of a constant returns that constant's
! 6426: value.</li>
! 6427: <li>The function formed by a character string between apostrophes returns
! 6428: that string.</li>
! 6429: <li>The function formed by the name of a buffer returns the contents of that
! 6430: buffer. If the named buffer is the picture buffer, then the name of the
! 6431: last picture encountered is returned. Otherwise, the buffer is a read
! 6432: buffer and the value returned is text previously read from the terminal.
! 6433: If the buffer is empty (no picture has been encountered or the
! 6434: <tt>Read</tt> rule has not been executed for the buffer), then the empty
! 6435: string is returned.</li>
! 6436: <li>The function formed by an attribute name takes the value of the
! 6437: indicated attribute for the element to which the variable applies. If the
! 6438: element does not have that attribute, then the element's ancestor are
! 6439: searched toward the root of the tree. If one of the ancestors does have
! 6440: the attribute then its value is used. If no ancestors have the attribute,
! 6441: then the value of the function is the empty string.</li>
1.18 cvs 6442: </ul>
1.30 ! cvs 6443: <pre> VariableSeq = Variable < Variable > .
! 6444: Variable = VarID ':' Function < Function > ';' .
1.1 cvs 6445: VarID = NAME .
6446: Function ='Value' '(' CounterID [ ':' Length ]
6447: [ ',' CounterStyle ] ')' /
6448: 'FileDir' / 'FileName' / 'Extension' /
6449: 'DocumentName' / 'DocumentDir' /
6450: ConstID / CharString /
6451: BufferID / AttrID .
6452: Length = NUMBER .
6453: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
6454: 'Uppercase' / 'Lowercase' .
1.18 cvs 6455: CharString = STRING .</pre>
1.30 ! cvs 6456:
1.18 cvs 6457: <blockquote class="example">
1.30 ! cvs 6458: <p><strong>Example:</strong></p>
! 6459:
! 6460: <p>To create, at the beginning of each section of the translated document,
! 6461: text composed of the string ``Section'' followed by the section number, the
! 6462: following <a name="varsectexample">variable definition</a> might be
! 6463: used:</p>
! 6464: <pre>VAR
1.18 cvs 6465: SectionVar : 'Section' Value(SectionNumber);</pre>
1.30 ! cvs 6466:
! 6467: <p>(see the definition of <a
! 6468: href="#sectnum"><tt>SectionNumber</tt></a>).</p>
! 6469:
! 6470: <p>The following variable definition can be used to create, at the beginning
! 6471: of each section, the text ``Level'' followed by the hierarchical level of
! 6472: the section. It used the constant defined above.</p>
! 6473: <pre> LevelVar : TxtLevel Value(SectionLevel);</pre>
! 6474:
! 6475: <p>(see the definitions of <a href="#sectnum"><tt>SectionLevel</tt></a> and
! 6476: of <a href="#levelexample"><tt>TxtLevel</tt></a>).</p>
! 6477:
! 6478: <p>To generate the translation of each section in a different file (see <a
! 6479: href="#sectc5220">rule <tt>ChangeMainFile</tt></a>), the name of these files
! 6480: might be defined by the following variable:</p>
! 6481: <pre> VarOutpuFile : FileName Value(SectionNumber)
1.18 cvs 6482: Extension;</pre>
1.30 ! cvs 6483:
! 6484: <p>If <tt>output.txt</tt> is the name of the <a name="varoutputfile">output
! 6485: file</a> specified when starting the translation program, translated
! 6486: sections are written in files <tt>output1.txt</tt>, <tt>output2.txt</tt>,
! 6487: etc.</p>
1.18 cvs 6488: </blockquote>
6489: </div>
6490:
6491: <div class="subsection">
1.30 ! cvs 6492: <h3><a name="sectc527">Translating structure elements</a></h3>
1.18 cvs 6493:
1.30 ! cvs 6494: <p>The <tt>RULES</tt> keyword introduces the translation rules which will be
1.1 cvs 6495: applied to the various structured element types. Translation rules can be
6496: specified for each element type defined in the structure schema, including the
1.18 cvs 6497: base types defined implicitly, whose names are <tt>TEXT_UNIT</tt>,
6498: <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>, <tt>GRAPHIC_UNIT</tt> and
6499: <tt>PAGE_UNIT</tt>. But it is not necessary to specify rules for every
6500: defined type.</p>
1.30 ! cvs 6501:
! 6502: <p>If there are no translation rules for an element type, the elements that it
1.1 cvs 6503: contains (and which may have rules themselves) will still be translated, but
6504: the translator will produce nothing for the element itself. To make the
1.18 cvs 6505: translator completely ignore the content of an element the <a
6506: href="#sectc5217"><tt>Remove</tt> rule</a> must be used.</p>
1.30 ! cvs 6507:
! 6508: <p>The translation rules for an element type defined in the structure schema
! 6509: are written using the name of the type followed by a colon and the list of
1.18 cvs 6510: applicable rules. When the element type is a <a href="#sectd3285">mark
6511: pair</a>, but only in this case, the type name must be preceded by the
6512: <tt>First</tt> or <tt>Second</tt> keyword. This keyword indicates whether the
6513: rules that follow apply to the first or second mark of the pair.</p>
1.30 ! cvs 6514:
! 6515: <p>The list of rules can take several forms. It may be a simple
! 6516: non-conditional rule. It can also be formed by a condition followed by one or
! 6517: more simple rules. Or it can be a block of rules beginning with the
! 6518: <tt>BEGIN</tt> keyword and ending with the <tt>END</tt> keyword and a
! 6519: semicolon. This block of rules can contain one or more simple rules and/or
! 6520: one or more conditions, each followed by one or more simple rules.</p>
! 6521: <pre> ElemSeq = TransType < TransType > .
1.1 cvs 6522: TransType = [ FirstSec ] ElemID ':' RuleSeq .
6523: FirstSec = 'First' / 'Second' .
1.30 ! cvs 6524: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
1.1 cvs 6525: Rule = SimpleRule / ConditionBlock .
6526: ConditionBlock = 'IF' ConditionSeq SimpleRuleSeq .
1.30 ! cvs 6527: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.18 cvs 6528: SimpleRule .</pre>
6529: </div>
1.1 cvs 6530:
1.18 cvs 6531: <div class="subsection">
1.30 ! cvs 6532: <h3><a name="sectc528">Conditional rules</a></h3>
1.1 cvs 6533:
1.30 ! cvs 6534: <p>In a translation schema, the translation rules are either associated with
1.1 cvs 6535: element types or with attribute values or with a specific presentation. They
6536: are applied by the translator each time an element of the corresponding type
6537: is encountered in the translated document or each time the attribute value is
6538: carried by an element or also, each time the specific translation is attached
6539: to an element. This systematic application of the rules can be relaxed: it is
6540: possible to add a condition to one or more rules, so that these rules are only
1.18 cvs 6541: applied when the condition is true.</p>
1.30 ! cvs 6542:
! 6543: <p>A condition begins with the keyword <tt>IF</tt>, followed by a sequence of
1.1 cvs 6544: elementary conditions. Elementary conditions are separated from each other by
1.18 cvs 6545: the <tt>AND</tt> keyword. If there is only one elementary condition, this
1.1 cvs 6546: keyword is absent. The rules are only applied if all the elementary
6547: conditions are true. The elementary condition can be negative; it is then
1.18 cvs 6548: preceded by the <tt>NOT</tt> keyword.</p>
1.30 ! cvs 6549:
! 6550: <p>When the translation rule(s) controlled by the condition apply to a
! 6551: reference element or a reference attribute, an elementary condition can also
! 6552: apply to element referred by this reference. The <tt>Target</tt> keyword is
! 6553: used for that purpose. It must appear before the keyword defining the
! 6554: condition type.</p>
! 6555:
! 6556: <p>Depending on their type, some conditions may apply either to the element
! 6557: with which they are associated, or to one of its ancestor. In the case of an
1.18 cvs 6558: ancestor, the key word <tt>Ancestor</tt> must be used, followed by</p>
6559: <ul>
1.30 ! cvs 6560: <li>either an integer which represents the number of levels in the tree
! 6561: between the element and the ancestor of interest,</li>
! 6562: <li>or the type name of the ancestor of interest. If that type is defined
! 6563: in a separate structure schema, the name of that schema must follow
! 6564: between parentheses.</li>
1.18 cvs 6565: </ul>
1.30 ! cvs 6566:
! 6567: <p>There is a special case for the parent element, which can be simply written
1.18 cvs 6568: <tt>Parent</tt> instead of <tt>Ancestor 1</tt>.</p>
1.30 ! cvs 6569:
! 6570: <p>Only conditions <tt>First</tt>, <tt>Last</tt>, <tt>Referred</tt>,
1.18 cvs 6571: <tt>Within</tt>, <tt>Attributes</tt>, <tt>Presentation</tt>, <tt>Comment</tt>
1.1 cvs 6572: and those concerning an attribute or a specific presentation can apply to an
1.18 cvs 6573: ancestor. Conditions <tt>Defined</tt>, <tt>FirstRef</tt>, <tt>LastRef</tt>,
6574: <tt>ExternalRef</tt>, <tt>Alphabet</tt>, <tt>FirstAttr</tt>,
6575: <tt>LastAttr</tt>, <tt>ComputedPage</tt>, <tt>StartPage</tt>,
6576: <tt>UserPage</tt>, <tt>ReminderPage</tt>, <tt>Empty</tt> cannot be preceded by
6577: keywords <tt>Parent</tt> or <tt>Ancestor</tt>.</p>
1.30 ! cvs 6578:
! 6579: <p>In condition <tt>Referred</tt> and in the condition that applies to a named
1.18 cvs 6580: attribute, a symbol '<tt>*</tt>' can indicate that the condition is related
1.5 cvs 6581: only to the element itself. If this symbol is not present, not only the
1.18 cvs 6582: element is considered, but also its ancestor, at any level.</p>
1.30 ! cvs 6583:
! 6584: <p>The form of an elementary condition varies according to the type of
1.18 cvs 6585: condition.</p>
1.1 cvs 6586:
1.18 cvs 6587: <div class="subsubsection">
6588: <h4><a name="sectd5281">Conditions based on the logical position of the
6589: element</a></h4>
1.30 ! cvs 6590:
! 6591: <p>The condition can be on the position of the element in the document's
! 6592: logical structure tree. It is possible to test whether the element is the
! 6593: first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
! 6594: not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>).</p>
! 6595:
! 6596: <p>It is also possible to test if the element is contained in an element of a
1.18 cvs 6597: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). If that
1.1 cvs 6598: element type is defined in a structure schema which is not the one which
6599: corresponds to the translation schema, the type name of this element must be
6600: followed, between parentheses, by the name of the structure schema which
1.18 cvs 6601: defines it.</p>
1.30 ! cvs 6602:
! 6603: <p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
1.18 cvs 6604: condition is satisfied only if the <em>parent</em> element has the type
6605: indicated. If the word <tt>Immediately</tt> is missing, the condition is
6606: satisfied if any <em>ancestor</em> has the type indicated.</p>
1.30 ! cvs 6607:
! 6608: <p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.1 cvs 6609: type. It specifies the number of ancestors of the indicated type that must be
6610: present for the condition to be satisfied. If the keyword
1.18 cvs 6611: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
6612: element must have the indicated type. The integer <i>n</i> must be positive
1.30 ! cvs 6613: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
1.1 cvs 6614: maximum or minimum number of ancestors. If these symbols are missing, the
1.18 cvs 6615: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
1.30 ! cvs 6616: this number is missing, it is equivalent to > 0.</p>
! 6617:
! 6618: <p>If the condition applies to translation rules associated with an attribute,
1.18 cvs 6619: i.e. if it is in the <tt>ATTRIBUTES</tt> section of the presentation schema,
1.11 cvs 6620: the condition can be simply an element name. Translation rules are then
1.18 cvs 6621: executed only if the attribute is attached to an element of that type. The
6622: keyword <tt>NOT</tt> before the element name indicates that the translation
6623: rules must be executed only if the element is not of the type indicated.</p>
6624: </div>
1.1 cvs 6625:
1.18 cvs 6626: <div class="subsubsection">
1.30 ! cvs 6627: <h4><a name="sectd5282">Conditions on references</a></h4>
1.1 cvs 6628:
1.30 ! cvs 6629: <p>References may be taken into account in conditions, which can be based on
! 6630: the fact that the element, or one of its ancestors (unless symbol <tt>*</tt>
! 6631: is present), is designated by a at least one reference (<tt>Referred</tt>) or
! 6632: by none (<tt>NOT Referred</tt>). If the element or attribute to which the
1.1 cvs 6633: condition is attached is a reference, the condition can be based on the fact
6634: that it acts as the first reference to the designated element
1.18 cvs 6635: (<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>), or as a reference to
6636: an element located in another document (<tt>ExternalRef</tt>). Like all
6637: conditions, conditions on references can be inverted by the <tt>NOT</tt>
6638: keyword.</p>
6639: </div>
6640:
6641: <div class="subsubsection">
1.30 ! cvs 6642: <h4><a name="sectd5283">Conditions on the parameters</a></h4>
1.18 cvs 6643:
1.30 ! cvs 6644: <p>Elements which are <a href="#sectc326">parameters</a> can be given a
1.18 cvs 6645: particular condition which is based on whether or not the parameter is given a
6646: value in the document (<tt>Defined</tt> or <tt>NOT Defined</tt>,
6647: respectively).</p>
6648: </div>
1.1 cvs 6649:
1.18 cvs 6650: <div class="subsubsection">
1.30 ! cvs 6651: <h4><a name="sectd5284">Conditions on the alphabets</a></h4>
1.1 cvs 6652:
1.30 ! cvs 6653: <p>The character string base type (and only this type) can use the condition
1.18 cvs 6654: <tt>Alphabet = a</tt> which indicates that the translation rule(s) should only
1.1 cvs 6655: apply if the alphabet of the character string is the one whose name appears
1.18 cvs 6656: after the equals sign (or is not, if there is a preceding <tt>NOT</tt>
1.1 cvs 6657: keyword). This condition cannot be applied to translation rules of an
1.18 cvs 6658: attribute.</p>
1.30 ! cvs 6659:
! 6660: <p>In the current implementation of Thot, the available alphabets are the
1.18 cvs 6661: <tt>Latin</tt> alphabet and the <tt>Greek</tt> alphabet.</p>
6662: </div>
1.1 cvs 6663:
1.18 cvs 6664: <div class="subsubsection">
1.30 ! cvs 6665: <h4><a name="sectd5285">Conditions on page breaks</a></h4>
1.1 cvs 6666:
1.30 ! cvs 6667: <p>The page break base type (and only this type) can use the following
1.18 cvs 6668: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>, and
6669: <tt>ReminderPage</tt>. The <tt>ComputedPage</tt> condition indicates that the
1.1 cvs 6670: translation rule(s) should apply if the page break was created automatically
1.18 cvs 6671: by Thot; the <tt>StartPage</tt> condition is true if the page break is
6672: generated before the element by the <tt>Page</tt> rule of the P language; the
6673: <tt>UserPage</tt> condition applies if the page break was inserted by the
6674: user; and the <tt>ReminderPage</tt> is applied if the page break is a reminder
6675: of page breaking.</p>
6676: </div>
1.1 cvs 6677:
1.18 cvs 6678: <div class="subsubsection">
1.30 ! cvs 6679: <h4><a name="sectd5286">Conditions on the element's content</a></h4>
1.1 cvs 6680:
1.30 ! cvs 6681: <p>The condition can be based on whether or not the element is empty. An
! 6682: element which has no children or whose leaves are all empty is considered to
! 6683: be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
! 6684: optionally preceded by the <tt>NOT</tt> keyword.</p>
1.18 cvs 6685: </div>
1.1 cvs 6686:
1.18 cvs 6687: <div class="subsubsection">
1.30 ! cvs 6688: <h4><a name="sectd5287">Conditions on the presence of comments</a></h4>
1.1 cvs 6689:
1.30 ! cvs 6690: <p>The condition can be based on the presence or absence of comments
! 6691: associated with the translated element. This condition is expressed by the
! 6692: keyword <tt>Comment</tt>, optionally preceded by the keyword <tt>NOT</tt>.</p>
1.18 cvs 6693: </div>
1.1 cvs 6694:
1.18 cvs 6695: <div class="subsubsection">
6696: <h4><a name="sectd5288">Conditions on the presence of specific presentation
6697: rules</a></h4>
1.30 ! cvs 6698:
! 6699: <p>The condition can be based on the presence or absence of specific
! 6700: presentation rules associated with the translated element, whatever the rules,
! 6701: their value or their number. This condition is expressed by the keyword
1.18 cvs 6702: <tt>Presentation</tt>, optionally preceded by the <tt>NOT</tt> keyword.</p>
6703: </div>
1.1 cvs 6704:
1.18 cvs 6705: <div class="subsubsection">
6706: <h4><a name="sectd5289">Conditions on the presence of logical
6707: attributes</a></h4>
1.30 ! cvs 6708:
! 6709: <p>In the same way, the condition can be based on the presence or absence of
1.1 cvs 6710: attributes associated with the translated elements, no matter what the
1.18 cvs 6711: attributes or their values. The <tt>Attributes</tt> keyword expresses this
6712: condition.</p>
6713: </div>
1.1 cvs 6714:
1.18 cvs 6715: <div class="subsubsection">
1.30 ! cvs 6716: <h4><a name="sectd52810">Conditions on logical attributes</a></h4>
1.1 cvs 6717:
1.30 ! cvs 6718: <p>If the condition appears in the translation rules of an attribute, the
1.18 cvs 6719: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
1.1 cvs 6720: the rules must only be applied if this attribute is the first attribute for
6721: the translated element or if it is the last (respectively). These conditions
1.18 cvs 6722: can also be inverted by the <tt>NOT</tt> keyword.</p>
1.30 ! cvs 6723:
! 6724: <p>Another type of condition can only be applied to the translation rules when
1.18 cvs 6725: the element being processed (or one of its ancestors if symbol <tt>*</tt> is
1.1 cvs 6726: missing) has a certain attribute, perhaps with a certain value or, in
6727: contrast, when the element does not have this attribute with this value. The
6728: condition is specified by writing the name of the attribute after the keyword
1.18 cvs 6729: <tt>IF</tt> or <tt>AND</tt>. The <tt>NOT</tt> keyword can be used to invert
1.1 cvs 6730: the condition. If the translation rules must be applied to any element which
6731: has this attribute (or does not have it, if the condition is inverted) no
6732: matter what the attribute's value, the condition is complete. If, in
6733: contrast, the condition applies to one or more values of the attribute, these
6734: are indicated after the name of the attribute, except for reference attributes
1.18 cvs 6735: which do not have values.</p>
1.30 ! cvs 6736:
! 6737: <p>The representation of the values of an <a name="relattr">attribute</a> in a
1.1 cvs 6738: condition depends on the attribute's type. For attributes with enumerated or
6739: textual types, the value (a name or character string between apostrophes,
6740: respectively) is simply preceded by an equals sign. For numeric attributes,
6741: the condition can be based on a single value or on a range of values. In the
6742: case of a unique value, this value (an integer) is simply preceded by an
1.18 cvs 6743: equals sign. Conditions based on ranges of values have several forms:</p>
6744: <ul>
1.30 ! cvs 6745: <li>all values less than a given value (the value is preceded by a ``less
! 6746: than'' sign).</li>
! 6747: <li>all values greater than a given value (the value is preceded by a
! 6748: ``greater than'' sign).</li>
! 6749: <li>all values falling in an interval, bounds included. The range of values
! 6750: is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
! 6751: Minimum and Maximum are integers.</li>
1.18 cvs 6752: </ul>
1.30 ! cvs 6753:
! 6754: <p>All numeric values may be negative. The integer is simply preceded by a
! 6755: minus sign.</p>
! 6756:
! 6757: <p>Both local and global attributes can be used in conditions.</p>
1.18 cvs 6758: </div>
1.1 cvs 6759:
1.18 cvs 6760: <div class="subsubsection">
1.30 ! cvs 6761: <h4><a name="sectd52811">Conditions on specific presentation rules</a></h4>
1.1 cvs 6762:
1.30 ! cvs 6763: <p>It is possible to apply translation rules only when the element being
1.1 cvs 6764: processed has or does not have a specific presentation rule, possibly with a
6765: certain value. The condition is specified by writing the name of the
1.18 cvs 6766: presentation rule after the keyword <tt>IF</tt> or <tt>AND</tt>. The
6767: <tt>NOT</tt> keyword can be used to invert the condition. If the translation
1.1 cvs 6768: rules must be applied to any element which has this presentation rule (or does
6769: not have it, if the condition is inverted) no matter what the rule's value,
6770: the condition is complete. If, in contrast, the condition applies to one or
6771: more values of the rule, these are indicated after the name of the
1.18 cvs 6772: attribute.</p>
1.30 ! cvs 6773:
! 6774: <p>The representation of presentation rule values in a condition is similar to
1.1 cvs 6775: that for attribute values. The representation of these values depend on the
6776: type of the presentation rule. There are three categories of presentation
1.18 cvs 6777: rules:</p>
6778: <ul>
1.30 ! cvs 6779: <li>those taking numeric values (<tt>Size, Indent, LineSpacing,
! 6780: LineWeight</tt>),</li>
! 6781: <li>those with values taken from a predefined list (<tt>Adjust, Justify,
! 6782: Hyphenate, Style, Weight, Font, UnderLine, Thickness,
! 6783: LineStyle</tt>),</li>
! 6784: <li>those whose value is a name (<tt>FillPattern, Background,
! 6785: Foreground</tt>).</li>
1.18 cvs 6786: </ul>
1.30 ! cvs 6787:
! 6788: <p>For presentation rules which take numeric values, the condition can take a
1.1 cvs 6789: unique value or a range of values. In the case of a unique value, this value
6790: (an integer) is simply preceded by an equals sign. Conditions based on ranges
1.18 cvs 6791: of values have several forms:</p>
6792: <ul>
1.30 ! cvs 6793: <li>all values less than a given value (the value is preceded by a ``less
! 6794: than'' sign).</li>
! 6795: <li>all values greater than a given value (the value is preceded by a
! 6796: ``greater than'' sign).</li>
! 6797: <li>all values falling in an interval, bounds included. The range of values
! 6798: is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
! 6799: Minimum and Maximum are integers.</li>
1.18 cvs 6800: </ul>
1.30 ! cvs 6801:
! 6802: <p>Values for the <tt>Indent</tt>rule may be negative. The integer is then
1.2 cvs 6803: simply preceded by a minus sign and represents how far the first line starts
1.18 cvs 6804: to the left of the other lines.</p>
1.30 ! cvs 6805:
! 6806: <p>For presentation rules whose values are taken from predefined lists, the
! 6807: value which satisfies the condition is indicated by an equals sign followed by
! 6808: the name of the value.</p>
! 6809:
! 6810: <p>For presentation rule whose values are names, the value which satisfies the
1.1 cvs 6811: condition is indicated by the equals sign followed by the value's name. The
1.18 cvs 6812: names of fill patterns (the <tt>FillPattern</tt> rule) and of colors (the
6813: <tt>Foreground</tt> and <tt>Background</tt> rules) known to Thot are the same
6814: as in the P language.</p>
1.30 ! cvs 6815:
! 6816: <p>The syntax of conditions based on the specific presentation is the same as
! 6817: the syntax used to express the <a href="#sectc5224">translation of specific
1.18 cvs 6818: presentation rules</a>.</p>
1.30 ! cvs 6819:
! 6820: <p>When a condition has only one rule, the condition is simply followed by
! 6821: that rule. If it has several rules, they are placed after the condition
! 6822: between the keywords <tt>BEGIN</tt> and <tt>END</tt>.</p>
1.18 cvs 6823: <pre> ConditionSeq = Condition [ 'AND' Condition ] .
1.1 cvs 6824: Condition = [ 'NOT' ] [ 'Target' ] Cond .
6825: Cond = CondElem / CondAscend .
6826: CondElem ='FirstRef' / 'LastRef' /
6827: 'ExternalRef' /
6828: 'Defined' /
6829: 'Alphabet' '=' Alphabet /
6830: 'ComputedPage' / 'StartPage' /
6831: 'UserPage' / 'ReminderPage' /
6832: 'Empty' /
1.11 cvs 6833: ElemID /
1.1 cvs 6834: 'FirstAttr' / 'LastAttr' .
6835: CondAscend = [ Ascend ] CondOnAscend .
6836: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
6837: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
6838: CondRelLevel = NUMBER .
6839: CondOnAscend ='First' / 'Last' /
6840: 'Referred' /
6841: [ 'Immediately' ] 'Within' [ NumParent ]
6842: ElemID [ ExtStruct ] /
6843: 'Attributes' /
6844: AttrID [ RelatAttr ] /
6845: 'Presentation' /
6846: PresRule /
6847: 'Comment' .
6848: NumParent = [ GreaterLess ] NParent .
1.30 ! cvs 6849: GreaterLess = '>' / '<' .
1.1 cvs 6850: NParent = NUMBER.
6851: ExtStruct = '(' ElemID ')' .
6852: Alphabet = NAME .
6853: RelatAttr ='=' Value /
1.30 ! cvs 6854: '>' [ '-' ] Minimum /
1.1 cvs 6855: '<' [ '-' ] Maximum /
6856: 'IN' '[' [ '-' ] MinInterval '..'
6857: [ '-' ] MaxInterval ']' .
6858: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
6859: Minimum = NUMBER .
6860: Maximum = NUMBER .
6861: MinInterval = NUMBER .
6862: MaxInterval = NUMBER .
6863: IntegerVal = NUMBER .
6864: TextVal = STRING .
1.18 cvs 6865: AttrValue = NAME .</pre>
1.30 ! cvs 6866:
1.18 cvs 6867: <blockquote class="example">
1.30 ! cvs 6868: <p><strong>Example:</strong></p>
! 6869:
! 6870: <p>Suppose that after each element of type Section_Title it is useful to
! 6871: produce the text <tt>\label{SectX}</tt> where <tt>X</tt> represents the
! 6872: section number, but only if the section is designated by one or more
! 6873: references in the document. The following conditional rule produces this
! 6874: effect:</p>
! 6875: <pre>RULES
1.1 cvs 6876: Section_Title :
6877: IF Referred
1.18 cvs 6878: Create ('\label{Sect' Value(UniqueSectNum) '}\12') After;</pre>
1.30 ! cvs 6879:
! 6880: <p>(the declaration of the <a href="#sectc5224"><tt>UniqueSectNum</tt>
! 6881: counter</a> is given above). The string <tt>\12</tt> represents a line
! 6882: break.</p>
1.18 cvs 6883: </blockquote>
1.30 ! cvs 6884:
1.18 cvs 6885: <blockquote class="example">
1.30 ! cvs 6886: <p><strong>Example:</strong></p>
! 6887:
! 6888: <p>Suppose that for elements of the Elmnt type it would be useful to produce
! 6889: a character indicating the value of the numeric attribute Level associated
! 6890: with the element: an ``A'' for all values of Level less than 3, a ``B'' for
! 6891: values between 3 and 10 and a ``C'' for values greater than 10. This can be
! 6892: achieved by writing the following rules for the Elmnt type:</p>
! 6893: <pre>RULES
1.1 cvs 6894: Elmnt :
6895: BEGIN
6896: IF Level < 3
6897: Create 'A';
6898: IF Level IN [3..10]
6899: Create 'B';
1.30 ! cvs 6900: IF Level > 10
1.1 cvs 6901: Create 'C';
1.18 cvs 6902: END;</pre>
6903: </blockquote>
6904: </div>
6905: </div>
1.1 cvs 6906:
1.18 cvs 6907: <div class="subsection">
1.30 ! cvs 6908: <h3><a name="sectc529">Translation rules</a></h3>
1.1 cvs 6909:
1.30 ! cvs 6910: <p>Fifteen types of translation rules can be associated with element types and
1.18 cvs 6911: attribute values. They are the <tt>Create</tt>, <tt>Write</tt>,
6912: <tt>Read</tt>, <tt>Include</tt>, <tt>Get</tt>, <tt>Copy</tt>, <tt>Use</tt>,
6913: <tt>Remove</tt>, <tt>NoTranslation</tt>, <tt>NoLineBreak</tt>,
6914: <tt>ChangeMainFile</tt>, <tt>RemoveFile</tt>, <tt>Set</tt>, <tt>Add</tt>,
6915: <tt>Indent</tt>, rules. Each rule has its own syntax, although they are all
6916: based on very similar models.</p>
6917: <pre> SimpleRule = 'Create' [ 'IN' VarID ] Object
1.1 cvs 6918: [ Position ] ';' /
6919: 'Write' Object [ Position ] ';' /
6920: 'Read' BufferID [ Position ] ';' /
6921: 'Include' File [ Position ] ';' /
6922: 'Get' [ RelPosition ] ElemID
6923: [ ExtStruct ]
6924: [ Position ] ';' /
6925: 'Copy' [ RelPosition ] ElemID
6926: [ ExtStruct ]
6927: [ Position ] ';' /
6928: 'Use' TrSchema [ 'For' ElemID ] ';' /
6929: 'Remove' ';' /
6930: 'NoTranslation' ';' /
6931: 'NoLineBreak' ';' /
6932: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 6933: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 6934: 'Set' CounterID InitValue [ Position ] ';' /
6935: 'Add' CounterID Increment [ Position ] ';' /
1.25 cvs 6936: 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .</pre>
1.18 cvs 6937: </div>
6938:
6939: <div class="subsection">
1.30 ! cvs 6940: <h3><a name="sectc5210">The <tt>Create</tt> rule</a></h3>
1.18 cvs 6941:
1.30 ! cvs 6942: <p>The most frequently used rule is undoubtedly the <tt>Create</tt> rule,
! 6943: which generates fixed or variable text (called an <em>object</em>) in the
! 6944: output file. The generated text can be made to appear either before or after
! 6945: the content of the element to which the rule applies. The rule begins with the
1.18 cvs 6946: <tt>Create</tt> keyword, followed by a specifier for the object and a keyword
6947: (<tt>Before</tt> or <tt>After</tt>) indicating the position of the generated
6948: text (<a href="#sectc5222">before or after</a> the element's content). If the
1.1 cvs 6949: position is not indicated, the object will be generated before the element's
6950: content. This rule, like all translation rules, is terminated by a
1.18 cvs 6951: semicolon.</p>
1.30 ! cvs 6952:
! 6953: <p>The <tt>Create</tt> keyword can be followed by the <tt>IN</tt> keyword and
! 6954: by the name of a variable. This means that the text generated by the rule
! 6955: must not be written in the main output file, but in the file whose name is
1.18 cvs 6956: specified by the variable.</p>
1.30 ! cvs 6957:
! 6958: <p>This allows the translation program to generate text in different files
! 6959: during the same run. These files do not need to be explicitely declared or
! 6960: opened. They do not need to be closed either, but if they contain temporary
! 6961: data, they can be removed (see the <a href="#sectc5220a"><tt>RemoveFile</tt>
! 6962: rule</a>). As soon as the translation program executes a <tt>Create</tt> rule
! 6963: for a file that is not yet open, it opens the file. These files are closed
! 6964: when the translation is finished.</p>
1.18 cvs 6965: <pre> 'Create' [ 'IN' VarID ] Object
1.1 cvs 6966: [ Position ] ';'
6967: Object = ConstID / CharString /
6968: BufferID /
6969: VarID /
1.30 ! cvs 6970: '(' Function < Function > ')' /
1.21 cvs 6971: [ 'Translated' ] AttrID /
1.1 cvs 6972: 'Value' /
6973: 'Content' /
6974: 'Comment' /
6975: 'Attributes' /
6976: 'Presentation' /
6977: 'RefId' /
6978: 'PairId' /
6979: 'FileDir' /
6980: 'FileName' /
6981: 'Extension' /
6982: 'DocumentName' /
6983: 'DocumentDir' /
6984: [ 'Referred' ] ReferredObject .
6985: Position ='After' / 'Before' .
6986:
6987: ReferredObject = VarID /
6988: ElemID [ ExtStruct ] /
6989: 'RefId' /
6990: 'DocumentName' /
1.18 cvs 6991: 'DocumentDir' .</pre>
1.30 ! cvs 6992:
! 6993: <p>The object to be generated can be:</p>
1.18 cvs 6994: <ul>
1.30 ! cvs 6995: <li>a constant string, specified by its name if it is declared in the
! 6996: schema's <tt>CONST</tt> section, or given directly as a value between
! 6997: apostrophes;</li>
! 6998: <li>the contents of a buffer, designated by the name of the buffer;</li>
! 6999: <li>a variable, designated by its name if it is declared in the translation
! 7000: schema's <tt>VAR</tt> section, or given directly between parentheses. The
! 7001: text generated is the value of that variable evaluated for the element to
! 7002: which the rule applies.</li>
! 7003: <li>the value of an attribute, if the element being translated has this
! 7004: attribute. The attribute is specified by its name. If it's a text
! 7005: attribute, it can be preceded by the <code>Translated</code> keyword,
! 7006: which causes the attribute value to be recoded using the text translation
! 7007: table defined by section <code><a
! 7008: href="#sectc5225">TEXTTRANSLATE</a></code>;</li>
! 7009: <li>the value of a specific presentation rule. This object can only be
! 7010: generated if the translation rule is for a <a href="#prestransl">specific
! 7011: presentation rule</a>. It is specified by the <tt>Value</tt>
! 7012: keyword;</li>
! 7013: <li>the element's content. That is, the content of the leaves of the
! 7014: subtree of the translated element. This is specified by the
! 7015: <tt>Content</tt> keyword;</li>
! 7016: <li>the comment attached to the element. When the element doesn't have a
! 7017: comment, nothing is generated. This is indicated by the <tt>Comment</tt>
! 7018: keyword;</li>
! 7019: <li>the translation of all attributes of the element (which is primarily
! 7020: used to apply the attribute translation rules <a
! 7021: href="#sectc5222">before</a> those of the element type). This is
! 7022: specified by the <tt>Attributes</tt> keyword.</li>
! 7023: <li>the translation of all of the element's specific presentation rules
! 7024: (which is primarily used to apply the translation rules for the specific
! 7025: presentation rules <a href="#sectc5222">before</a> those of the element or
! 7026: its attributes). This option is specified by the <tt>Presentation</tt>
! 7027: keyword;</li>
! 7028: <li>The value of the reference's identifier.<br>
! 7029: Thot associates a unique identifier with each element in a document. This
! 7030: identifier (called <em>reference's identifier</em> or <em>label</em>) is a
! 7031: character string containing the letter `L' followed by digits. Thot uses
! 7032: it in references for identifying the referred element.<br>
! 7033: The <tt>RefId</tt> keyword produces the reference's identifier of the
! 7034: element to which the translation rule is applied, or the reference's
! 7035: identifier of its first ancestor that is referred by a reference or that
! 7036: can be referred by a reference.</li>
! 7037: <li>the value of a mark pair's unique identifier. This may only be used for
! 7038: <a href="#sectd3285">mark pairs</a> and is indicated by the
! 7039: <tt>PairId</tt> keyword.</li>
! 7040: <li>the directory containing the file being generated (this string includes
! 7041: an ending '/', if it is not empty). This is indicated by the
! 7042: <tt>FileDir</tt> keyword.</li>
! 7043: <li>the name of the file being generated (only the name, without the
! 7044: directory and without the extension). This is indicated by the
! 7045: <tt>FileName</tt> keyword.</li>
! 7046: <li>the extension of the file being generated (this string starts with a
! 7047: dot, if it is not empty). This is indicated by the <tt>Extension</tt>
! 7048: keyword.</li>
! 7049: <li>the name of the document being translated. This is indicated by the
! 7050: <tt>DocumentName</tt> keyword.</li>
! 7051: <li>the directory containing the document being translated. This is
! 7052: indicated by the <tt>DocumentDir</tt> keyword.</li>
1.18 cvs 7053: </ul>
1.30 ! cvs 7054:
! 7055: <p>When the rule applies to a reference (an element or an attribute defined as
! 7056: a reference in the structure schema), it can generate a text related to the
1.21 cvs 7057: element referred by that reference. The rule name is then followed by the
1.18 cvs 7058: <tt>Referred</tt> keyword and a specification of the object to be generated
7059: for the referred element. This specification can be:</p>
7060: <ul>
1.30 ! cvs 7061: <li>the name of a variable. The rule generates the value of that variable,
! 7062: computed for the referred element.</li>
! 7063: <li>an element type. The rule generates the translation of the element of
! 7064: that type, which is in the subtree of the referred element. If this
! 7065: element is not defined in the structure schema which corresponds to the
! 7066: translation schema (that is, an object defined in another schema), the
! 7067: element's type name must be followed by the name of its structure schema
! 7068: between parentheses.</li>
! 7069: <li>the <tt>RefId</tt> keyword. The rule generates the reference's
! 7070: identifier of the referred element.</li>
! 7071: <li>the <tt>DocumentName</tt> keyword. The rule generates the name of the
! 7072: document to which the referred element belongs.</li>
! 7073: <li>the <tt>DocumentDir</tt> keyword. The rule generates the name of the
! 7074: directory that contains the document of the referred element.</li>
1.18 cvs 7075: </ul>
7076: </div>
1.1 cvs 7077:
1.18 cvs 7078: <div class="subsection">
1.30 ! cvs 7079: <h3><a name="sectc5211">The <tt>Write</tt> rule</a></h3>
1.1 cvs 7080:
1.30 ! cvs 7081: <p>The <tt>Write</tt> has the same syntax as the <tt>Create</tt> rule. It
! 7082: also produces the same effect, but the generated text is displayed on the
! 7083: user's terminal during the translation of the document, instead of being
! 7084: produced in the translated document. This is useful for helping the user keep
! 7085: track of the progress of the translation and for prompting the user on the
! 7086: terminal for input required by the <tt>Read</tt> rule.</p>
1.18 cvs 7087: <pre> 'Write' Object [ Position ] ';'</pre>
1.30 ! cvs 7088:
! 7089: <p>Notice: if the translator is launched by the editor (by the ``Save as''
1.18 cvs 7090: command), messages produced by the <tt>Write</tt> rule are not displayed.</p>
1.30 ! cvs 7091:
1.18 cvs 7092: <blockquote class="example">
1.30 ! cvs 7093: <p><strong>Example:</strong></p>
! 7094:
! 7095: <p>To make the translator display the number of each section being
! 7096: translated on the user's terminal, the following rule is specified for the
! 7097: <tt>Section</tt> element type:</p>
! 7098: <pre>Section : BEGIN
1.1 cvs 7099: Write VarSection;
7100: ...
1.18 cvs 7101: END;</pre>
1.30 ! cvs 7102:
! 7103: <p>(see <a href="#varsectexample">above</a> for the definition of the
! 7104: <tt>VarSection</tt> variable).</p>
! 7105:
! 7106: <p>To display text on the terminal before issuing a read operation with the
! 7107: <tt>Read</tt> rule, the following rule is used:</p>
! 7108: <pre>BEGIN
1.1 cvs 7109: Write 'Enter the name of the destination: ';
7110: ...
1.18 cvs 7111: END;</pre>
7112: </blockquote>
7113: </div>
7114:
7115: <div class="subsection">
1.30 ! cvs 7116: <h3><a name="sectc5212">The <tt>Read</tt> rule</a></h3>
1.18 cvs 7117:
1.30 ! cvs 7118: <p>The <tt>Read</tt> rule reads text from the terminal during the translation
! 7119: of the document and saves the text read in one of the buffers declared in the
1.18 cvs 7120: <tt>BUFFERS</tt> section of the schema. The buffer to be used is indicated by
7121: its name, after the <tt>READ</tt> keyword. This name can be followed, as in
7122: the <tt>Create</tt> and <tt>Write</tt> rules, by a keyword indicating if the
7123: read operation must be performed <tt>Before</tt> or <tt>After</tt> the
1.1 cvs 7124: translation of the element's content. If this keyword is absent, the read
7125: operation is done beforehand. The text is read into the buffer and remains
1.5 cvs 7126: there until a rule using the same buffer - possibly the same rule - is
1.18 cvs 7127: applied.</p>
7128: <pre> 'Read' BufferID [ Position ] ';'</pre>
1.30 ! cvs 7129:
1.18 cvs 7130: <blockquote class="example">
1.30 ! cvs 7131: <p><strong>Example:</strong></p>
! 7132:
! 7133: <p>The following set of rules tells the user that the translator is waiting
! 7134: for the entry of some text, reads this text into a buffer and copies the
! 7135: text into the translated document.</p>
! 7136: <pre>BEGIN
1.1 cvs 7137: Write 'Enter the name of the destination: ';
7138: Read DestName;
7139: Create DestName;
7140: ...
1.18 cvs 7141: END;</pre>
1.30 ! cvs 7142:
! 7143: <p>(see <a href="#destname">above</a> the definition of
! 7144: <tt>DestName</tt>).</p>
1.18 cvs 7145: </blockquote>
7146: </div>
7147:
7148: <div class="subsection">
1.30 ! cvs 7149: <h3><a name="sectc5213">The <tt>Include</tt> rule</a></h3>
1.18 cvs 7150:
1.30 ! cvs 7151: <p>The <tt>Include</tt> rule, like the <tt>Create</tt> rule, is used to
! 7152: produce text in the translated document. It inserts constant text which is
! 7153: not defined in the translation schema, but is instead taken from a file. The
1.18 cvs 7154: file's name is specified after the <tt>Include</tt> keyword, either directly
1.1 cvs 7155: as a character string between apostrophes or as the name of one of the buffers
1.18 cvs 7156: declared in the <tt>BUFFERS</tt> section of the schema. In the latter case,
1.1 cvs 7157: the buffer is assumed to contain the file's name. This can be used when the
7158: included file's name is known only at the moment of translation. This only
1.18 cvs 7159: requires that the <tt>Include</tt> rule is preceded by a <tt>Read</tt> rule
7160: which puts the name of the file desired by the user into the buffer.</p>
1.30 ! cvs 7161:
! 7162: <p>Like the other rules, it is possible to specify whether the inclusion will
1.1 cvs 7163: occur before or after the element's content, with the default being before.
7164: The file inclusion is only done at the moment of translation, not during the
7165: compilation of the translation schema. Thus, the file to be included need not
7166: exist during the compilation, but it must be accessible at the time of
7167: translation. Its contents can also be modified between two translations, thus
7168: producing different results, even if neither the document or the translation
1.18 cvs 7169: schema are modified.</p>
1.30 ! cvs 7170:
! 7171: <p>During translation, the file to be included is searched for along the
! 7172: schema directory path (indicated by the environment variable
! 7173: <tt>THOTSCH</tt>). The file name is normally only composed of a simple name,
! 7174: without specification of a complete file path. However, if the filename
! 7175: starts with a '/', it is considered as an absolute path.</p>
1.18 cvs 7176: <pre> 'Include' File [ Position ] ';'
1.6 cvs 7177: File = FileName / BufferID .
1.18 cvs 7178: FileName = STRING .</pre>
1.30 ! cvs 7179:
1.18 cvs 7180: <blockquote class="example">
1.30 ! cvs 7181: <p><strong>Example:</strong></p>
! 7182:
! 7183: <p>Suppose that it is desirable to print documents of the Article class with
! 7184: a formatter which requires a number of declarations and definitions at the
! 7185: beginning of the file. The <tt>Include</tt>rule can be used to achieve
! 7186: this. All the declarations and definitions a replaced in a file called
! 7187: <tt>DeclarArt</tt> and then the <tt>Article</tt> element type is given the
! 7188: following rule:</p>
! 7189: <pre>Article : BEGIN
1.1 cvs 7190: Include 'DeclarArt' Before;
7191: ...
1.18 cvs 7192: END;</pre>
7193: </blockquote>
7194: </div>
7195:
7196: <div class="subsection">
1.30 ! cvs 7197: <h3><a name="sectc5214">The <tt>Get</tt> rule</a></h3>
1.18 cvs 7198:
1.30 ! cvs 7199: <p>The <tt>Get</tt> rule is used to change the order in which the elements
! 7200: appear in the translated document. More precisely, it produces the
! 7201: translation of a specified element before or after the translation of the
! 7202: content of the element to which the rule applies. The <tt>Before</tt> and
! 7203: <tt>After</tt> keywords are placed at the end of the rule to specify whether
! 7204: the operation should be performed before or after translation of the rule's
! 7205: element (the default is before). The type of the element to be moved must be
! 7206: specified after the <tt>Get</tt> keyword, optionally preceded by a keyword
! 7207: indicating where the element will be found in the logical structure of the
! 7208: document:</p>
1.18 cvs 7209: <dl>
1.30 ! cvs 7210: <dt><tt>Included</tt></dt>
! 7211: <dd>The element to be moved is the first element of the indicated type
! 7212: which is found inside the element to which the rule applies.</dd>
! 7213: <dt><tt>Referred</tt></dt>
! 7214: <dd>This keyword can only be used if the rule applies to a reference
! 7215: element. The element to be moved is either the element designated by the
! 7216: reference (if that element is of the specified type), or the first
! 7217: element of the desired type contained within the element designated by
! 7218: the reference.</dd>
! 7219: <dt>no keyword</dt>
! 7220: <dd>If the element to be moved is an associated element, defined in the <a
! 7221: href="#sectc314"><tt>ASSOC</tt> section</a> of the structure schema, all
! 7222: associated elements of this type which have not been translated yet are
! 7223: then translated. Certain elements may in fact have already been
! 7224: translated by a <tt>Get Referred</tt> rule.
! 7225: <p>If the element to be moved is not an associated element, the
! 7226: translator takes the first element of the indicated type from among the
! 7227: siblings of the rule's element. This is primarily used to change the
! 7228: order of the components of an aggregate.</p>
! 7229: </dd>
1.18 cvs 7230: </dl>
1.30 ! cvs 7231:
! 7232: <p>If the element to be moved is defined in a structure schema which is not
! 7233: the one which corresponds to the translation schema (in the case of an
! 7234: included object with a different schema), the type name of this element must
! 7235: be followed, between parentheses, by the name of the structure schema which
1.18 cvs 7236: defines it.</p>
7237: <pre> 'Get' [ RelPosition ] ElemID
1.6 cvs 7238: [ ExtStruct ]
7239: [ Position ] ';' /
7240: RelPosition = 'Included' / 'Referred' .
1.18 cvs 7241: ExtStruct = '(' ElemID ')' .</pre>
1.30 ! cvs 7242:
! 7243: <p>The <tt>Get</tt> rule has no effect if the element which it is supposed to
1.1 cvs 7244: move has already been translated. Thus, the element will not be duplicated.
7245: It is generally best to associate the rule with the first element which will
7246: be encountered by the translator in its traversal of the document. Suppose an
1.18 cvs 7247: aggregate has two elements <tt>A</tt> and <tt>B</tt>, with <tt>A</tt>
1.1 cvs 7248: appearing first in the logical structure. To permute these two elements, a
1.18 cvs 7249: <tt>Get B before</tt> rule should be associated with the <tt>A</tt> element
7250: type, not the inverse. Similarly, a rule of the form <tt>Get Included X
7251: After</tt>, even though syntactically correct, makes no sense since, by the
1.1 cvs 7252: time it will be applied, after the translation of the contents of the element
1.18 cvs 7253: to which it is attached, the <tt>X</tt> element will already have been
7254: translated.</p>
1.30 ! cvs 7255:
! 7256: <p>The <tt>Get</tt> rule is the only way to obtain the translation of the
1.1 cvs 7257: associated elements. In fact, the translator only traverses the primary tree
7258: of the document and thus does not translate the associated elements, except
1.18 cvs 7259: when the translation is explicitly required by a <tt>Get Referred Type</tt> or
7260: <tt>Get Type</tt> rule where <tt>Type</tt> is an associated element type.</p>
1.30 ! cvs 7261:
1.18 cvs 7262: <blockquote class="example">
1.30 ! cvs 7263: <p><strong>Example:</strong></p>
! 7264:
! 7265: <p>The structure schema defined figures as associated element which are
! 7266: composed of some content and a caption. Moreover, it is possible to make
! 7267: references to figures, using elements of the <tt>RefFigure</tt> type:</p>
! 7268: <pre> ...
1.1 cvs 7269: RefFigure = REFERENCE(Figure);
7270: ASSOC
1.6 cvs 7271: Figure = BEGIN
7272: Content = NATURE;
7273: Caption = Text;
7274: END;
1.18 cvs 7275: ...</pre>
1.30 ! cvs 7276:
! 7277: <p>Suppose it would be useful to make a figure appear in the translated
! 7278: document at the place in the text where the first reference to the figure is
! 7279: made. If some figures are not referenced, then they would appear at the end
! 7280: of the document. Also, each figure's caption should appear before the
! 7281: content. The following rules in the translation schema will produce this
! 7282: result:</p>
! 7283: <pre>Article : BEGIN
1.1 cvs 7284: ...
7285: Get Figures After;
7286: END;
7287: RefFigure : BEGIN
7288: If FirstRef Get Referred Figure;
7289: ...
7290: END;
7291: Content : BEGIN
7292: Get Caption Before;
7293: ...
1.18 cvs 7294: END;</pre>
7295: </blockquote>
7296: </div>
7297:
7298: <div class="subsection">
1.30 ! cvs 7299: <h3><a name="sectc5215">The <tt>Copy</tt> rule</a></h3>
1.18 cvs 7300:
1.30 ! cvs 7301: <p>Like the <tt>Get</tt> rule, the <tt>Copy</tt> rule generates the
! 7302: translation of a specified element, but it acts even if the element has
! 7303: already been translated and it allows to copy it or to translate it later.
! 7304: Both rules have the same syntax.</p>
1.18 cvs 7305: <pre> 'Copy' [ RelPosition ] ElemID
7306: [ ExtStruct ] [ Position ] ';'</pre>
7307: </div>
7308:
7309: <div class="subsection">
1.30 ! cvs 7310: <h3><a name="sectc5216">The <tt>Use</tt> rule</a></h3>
1.18 cvs 7311:
1.30 ! cvs 7312: <p>The <tt>Use</tt> rule specifies the translation schema to be applied to
1.1 cvs 7313: objects of a certain class that are part of the document. This rule only
7314: appears in the rules for the root element of the document (the first type
1.18 cvs 7315: defined after the <tt>STRUCT</tt> keyword in the structure schema) or the
1.1 cvs 7316: rules of an element defined by an external structure (by another structure
1.18 cvs 7317: schema). Also, the <tt>Use</tt> rule cannot be conditional.</p>
1.30 ! cvs 7318:
! 7319: <p>If the rule is applied to an element defined by an external structure, the
1.18 cvs 7320: <tt>Use</tt> keyword is simply followed by the name of the translation schema
1.1 cvs 7321: to be used for element constructed according to that external structure. If
7322: the rule is applied to the document's root element, it is formed by the
1.18 cvs 7323: <tt>Use</tt> keyword followed by the translation schema's name, the
7324: <tt>For</tt> keyword and the name of the external structure to which the
7325: indicated translation schema should be applied.</p>
7326: <pre> 'Use' TrSchema [ 'For' ElemID ] ';'
7327: TrSchema = NAME .</pre>
1.30 ! cvs 7328:
! 7329: <p>If no <tt>Use</tt> rule defines the translation schema to be used for an
1.1 cvs 7330: external structure which appears in a document, the translator asks the user,
7331: during the translation process, which schema should be used. Thus, it is not
1.18 cvs 7332: necessary to give the translation schema a <tt>Use</tt> rule for every
1.1 cvs 7333: external structure used, especially when the choice of translation schemas is
1.18 cvs 7334: to be left to the user.</p>
1.30 ! cvs 7335:
! 7336: <p>Notice: if the translator is launched by the editor (by the ``Save as''
1.18 cvs 7337: command), prompts are not displayed.</p>
1.30 ! cvs 7338:
1.18 cvs 7339: <blockquote class="example">
1.30 ! cvs 7340: <p><strong>Example:</strong></p>
! 7341:
! 7342: <p>The <tt>Article</tt> structure schema uses the <tt>Formula</tt> external
! 7343: structure, defined by another structure schema, for mathematical
! 7344: formulas:</p>
! 7345: <pre>STRUCTURE Article;
1.1 cvs 7346: ...
7347: STRUCT
7348: Article = ...
7349: ...
7350: Formula_in_text = Formula;
7351: Isolated_formula = Formula;
7352: ...
1.18 cvs 7353: END</pre>
1.30 ! cvs 7354:
! 7355: <p>Suppose that it would be useful to use the <tt>FormulaT</tt> translation
! 7356: schema for the formulas of an article. This can be expressed in two
! 7357: different ways in the <tt>Article</tt> class translation schema, using the
! 7358: rules:</p>
! 7359: <pre>RULES
1.1 cvs 7360: Article :
1.18 cvs 7361: Use FormulaT for Formula;</pre>
1.30 ! cvs 7362:
! 7363: <p>or:</p>
! 7364: <pre>RULES
1.1 cvs 7365: ...
7366: Formula :
1.18 cvs 7367: Use FormulaT;</pre>
7368: </blockquote>
7369: </div>
7370:
7371: <div class="subsection">
1.30 ! cvs 7372: <h3><a name="sectc5217">The <tt>Remove</tt> rule</a></h3>
1.18 cvs 7373:
1.30 ! cvs 7374: <p>The <tt>Remove</tt> rule indicates that nothing should be generated, in the
1.1 cvs 7375: translated document, for the content of the element to which the rule applies.
7376: The content of that element is simply ignored by the translator. This does
7377: not prevent the generation of text for the element itself, using the
1.18 cvs 7378: <tt>Create</tt> or <tt>Include</tt> rules, for example.</p>
1.30 ! cvs 7379:
! 7380: <p>The <tt>Remove</tt> rule is simply written with the <tt>Remove</tt>
! 7381: keyword. It is terminated, like all rules, by a semicolon.</p>
1.18 cvs 7382: <pre> 'Remove' ';'</pre>
7383: </div>
7384:
7385: <div class="subsection">
1.30 ! cvs 7386: <h3><a name="sectc5218">The <tt>NoTranslation</tt> rule</a></h3>
1.18 cvs 7387:
1.30 ! cvs 7388: <p>The <tt>NoTranslation</tt> rule indicates to the translator that it must
! 7389: not translate the content of the leaves of the element to which it applies. In
1.18 cvs 7390: contrast to the <tt>Remove</tt> rule, it does not suppress the content of the
1.1 cvs 7391: element, but it inhibits the translation of character strings, symbols, and
7392: graphical elements contained in the element. These are retrieved so that
1.18 cvs 7393: after the translation of the document, the rules of the <a
7394: href="#sectc5225"><tt>TEXTTRANSLATE</tt>, <tt>SYMBTRANSLATE</tt> and
7395: <tt>GRAPHTRANSLATE</tt> sections</a> will not be applied to them.</p>
1.30 ! cvs 7396:
! 7397: <p>The <tt>NoTranslation</tt> rule is written with the <tt>NoTranslation</tt>
1.18 cvs 7398: keyword followed by a semicolon.</p>
7399: <pre> 'NoTranslation' ';'</pre>
7400: </div>
7401:
7402: <div class="subsection">
1.30 ! cvs 7403: <h3><a name="sectc5219">The <tt>NoLineBreak</tt> rule</a></h3>
1.18 cvs 7404:
1.30 ! cvs 7405: <p>The <tt>NoLineBreak</tt> rule indicates to the translator that it must not
1.1 cvs 7406: generate additional line breaks in the output produced for the element to
1.18 cvs 7407: which it applies. This is as if it was an <a href="#sectc522">instruction
7408: <tt>LINELENGTH 0;</tt></a> at the beginning of the translation schema, but
7409: only for the current element.</p>
1.30 ! cvs 7410:
! 7411: <p>The <tt>NoLineBreak</tt> rule is written with the <tt>NoLineBreak</tt>
! 7412: keyword followed by a semicolon.</p>
1.18 cvs 7413: <pre> 'NoLineBreak' ';'</pre>
7414: </div>
1.1 cvs 7415:
1.18 cvs 7416: <div class="subsection">
1.30 ! cvs 7417: <h3><a name="sectc5220">The <tt>ChangeMainFile</tt> rule</a></h3>
1.1 cvs 7418:
1.30 ! cvs 7419: <p>When the translation program starts, it opens a main output file, whose
! 7420: name is given as a parameter of the translator. All <a
1.18 cvs 7421: href="#sectc5210"><tt>Create</tt> rules</a> without explicit indication of the
7422: output file write sequentially in this file. When a <tt>ChangeMainFile</tt>
7423: rule is executed, the main output file is closed and it is replaced by a new
7424: one, whose name is specified in the <tt>ChangeMainFile</tt> rule. The
7425: <tt>Create</tt> rules without indication of the output file that are then
7426: executed write in this new file. Several <tt>ChangeMainFile</tt> rules can be
7427: executed during the same translation, for dividing the main output into
7428: several files.</p>
1.30 ! cvs 7429:
! 7430: <p>This rule is written with the <tt>ChangeMainFile</tt> keyword followed by
! 7431: the name of a variable that specifies the name of the new main file. The
! 7432: keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule
! 7433: to specify whether the operation should be performed before or after
! 7434: translation of the rule's element (the default is before). This rule, like all
! 7435: translation rules, is terminated by a semicolon.</p>
1.18 cvs 7436: <pre> 'ChangeMainFile' VarID [ Position ] ';'</pre>
1.30 ! cvs 7437:
1.18 cvs 7438: <blockquote class="example">
1.30 ! cvs 7439: <p><strong>Example:</strong></p>
! 7440:
! 7441: <p>To generate the translation of each section in a different file, the
! 7442: following rule can be associated with type <tt>Section</tt>. That rule uses
! 7443: the <a href="#varoutputfile"><tt>VarOutpuFile</tt> variable</a> defined
! 7444: above.</p>
! 7445: <pre> Section:
1.18 cvs 7446: ChangeMainFile VarOutpuFile Before;</pre>
1.30 ! cvs 7447:
! 7448: <p>If <tt>output.txt</tt> is the name of the output file specified when
! 7449: starting the translation program, translated sections are written in files
! 7450: <tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>
1.18 cvs 7451: </blockquote>
7452: </div>
1.1 cvs 7453:
1.18 cvs 7454: <div class="subsection">
1.30 ! cvs 7455: <h3><a name="sectc5220a">The <tt>RemoveFile</tt> rule</a></h3>
1.14 cvs 7456:
1.30 ! cvs 7457: <p>Files may be used for storing temporary data that are no longer needed when
1.18 cvs 7458: the translation of a document is complete. These files may be removed by the
7459: <tt>RemoveFile</tt> rule.</p>
1.30 ! cvs 7460:
! 7461: <p>This rule is written with the <tt>RemoveFile</tt> keyword followed by the
! 7462: name of a variable that specifies the name of the file to be removed. The
! 7463: keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule
! 7464: to specify whether the operation should be performed before or after
! 7465: translation of the rule's element (the default is before). This rule, like
! 7466: all translation rules, is terminated by a semicolon.</p>
1.18 cvs 7467: <pre> 'RemoveFile' VarID [ Position ] ';'</pre>
7468: </div>
7469:
7470: <div class="subsection">
1.30 ! cvs 7471: <h3><a name="sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a></h3>
1.18 cvs 7472:
1.30 ! cvs 7473: <p>The <tt>Set</tt> and <tt>Add</tt> rules are used for modifying the value of
1.18 cvs 7474: counters that have no <a href="#sectc524">counting function</a>. Only this
7475: type of counter can be used in the <tt>Set</tt> and <tt>Add</tt> rules.</p>
1.30 ! cvs 7476:
! 7477: <p>Both rules have the same syntax: after the keyword <tt>Set</tt> or
1.18 cvs 7478: <tt>Add</tt> appear the counter name and the value to assign to the counter
7479: (<tt>Set</tt> rule) or the value to be added to the counter (<tt>Add</tt>
7480: rule). The keyword <tt>Before</tt> or <tt>After</tt> can follow that value to
1.1 cvs 7481: indicate when the rule must be applied: before or after the element's content
1.18 cvs 7482: is translated. By default, <tt>Before</tt> is assumed. A semicolon terminates
7483: the rule.</p>
7484: <pre> 'Set' CounterID InitValue [ Position ] ';' /
7485: 'Add' CounterID Increment [ Position ] ';'</pre>
7486: </div>
7487:
7488: <div class="subsection">
1.30 ! cvs 7489: <h3><a name="sectc5221a">The <tt>Indent</tt> rule</a></h3>
1.18 cvs 7490:
1.30 ! cvs 7491: <p>The <tt>Indent</tt> rule is used to modify the value of text indentation in
1.18 cvs 7492: the output files.</p>
1.30 ! cvs 7493:
! 7494: <p>Each time the translator creates a new line in an output file, it generates
! 7495: a variable number of space characters at the beginning of the new line. By
1.25 cvs 7496: default, the number of these characters (the indentation value) is 0. It can
7497: be changed with the <tt>Indent</tt> rule.</p>
1.30 ! cvs 7498:
! 7499: <p>In its simple form, the rule begins with the <tt>Indent</tt> keyword,
1.25 cvs 7500: followed by the indentation sign (optional) and value and a keyword
1.30 ! cvs 7501: <tt>Before</tt> or <tt>After</tt> indicating that the indentation should be
! 7502: changed <a href="#sectc5222">before or after</a> the element's content is
! 7503: generated. If the position is not indicated, the indentation is changed
1.25 cvs 7504: before the element's content is generated. This rule, like all translation
7505: rules, is terminated by a semicolon.</p>
1.30 ! cvs 7506:
! 7507: <p>The indentation value is indicated by an integer, which is the number of
! 7508: space characters to be generated at the beginning of each new line. A sign
1.18 cvs 7509: (<tt>+</tt> or <tt>-</tt>) can appear before the integer to indicate that the
7510: value is relative: the current value of indentation is incremented (if sign is
7511: <tt>+</tt>) or decremented (if sign is <tt>-</tt>) by the specified value.</p>
1.30 ! cvs 7512:
! 7513: <p>Keyword <tt>Suspend</tt> or <tt>Resume</tt> can appear instead of the
1.25 cvs 7514: (possibly signed) identation value. <tt>Suspend</tt> means that the new
1.30 ! cvs 7515: indentation value to be used is zero until another <tt>Indent</tt> rule is
! 7516: executed and changes the indentation value. <tt>Resume</tt> means that the
! 7517: indentation value that was used before the last <tt>Indent Suspend</tt> was
! 7518: executed becomes the new value. Only one <tt>Suspend</tt> can be used before
! 7519: a <tt>Resume</tt>; <tt>Supend</tt>-<tt>Resume</tt> pairs can not be
! 7520: nested.</p>
! 7521:
! 7522: <p>Like the <a href="#sectc5210"><tt>Create</tt> rule</a>, the <tt>Indent</tt>
1.18 cvs 7523: keyword can be followed by the <tt>IN</tt> keyword and by the name of a <a
7524: href="#sectc526">variable</a>. This means that the rule must not change
1.10 cvs 7525: indentation in the main output file, but in the file whose name is specified
7526: by the variable (by default, indentation is changed in the main output
1.18 cvs 7527: file).</p>
1.25 cvs 7528: <pre> 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .
1.10 cvs 7529:
1.25 cvs 7530: Indent = 'Suspend' / 'Resume' / [ IndentSign ] IndentValue .
1.10 cvs 7531: IndentSign = '+' / '-' .
1.18 cvs 7532: IndentValue = NUMBER .</pre>
7533: </div>
1.10 cvs 7534:
1.18 cvs 7535: <div class="subsection">
1.30 ! cvs 7536: <h3><a name="sectc5222">Rule application order</a></h3>
1.1 cvs 7537:
1.30 ! cvs 7538: <p>The translator translates the elements which comprise the document in the
1.18 cvs 7539: order induced by the tree structure, except when the <tt>Get</tt> rule is used
1.1 cvs 7540: to change the order of translation. For each element, the translator first
7541: applies the rules specified for the element's type that must be applied before
1.18 cvs 7542: translation of the element's content (rules ending with the <tt>Before</tt>
1.1 cvs 7543: keyword or which have no position keyword). If several rules meet these
7544: criteria, the translator applies them in the order in where they appear in the
1.18 cvs 7545: translation schema.</p>
1.30 ! cvs 7546:
! 7547: <p>It then applies all <a href="#sectc5223">rules for the attributes</a> which
1.1 cvs 7548: the element has and which must be applied before the translation of the
1.18 cvs 7549: element's content (rules ending with the <tt>Before</tt> keyword or which have
1.1 cvs 7550: no position keyword). For one attribute value, the translator applies the
1.18 cvs 7551: rules in the order in which they are defined in the translation schema.</p>
1.30 ! cvs 7552:
! 7553: <p>The same procedure is followed with translation rules for specific
1.18 cvs 7554: presentations.</p>
1.30 ! cvs 7555:
! 7556: <p>Next, the element's content is translated, as long as a <tt>Remove</tt>
! 7557: rule does not apply.</p>
! 7558:
! 7559: <p>In the next step, the translator applies rules for the specific
! 7560: presentation of the element that are to be applied after translation of the
! 7561: content (rules which end with the <tt>After</tt> keyword). The rules for each
! 7562: type of presentation rule or each value are applied in the order in which the
1.18 cvs 7563: translation appear in the schema.</p>
1.30 ! cvs 7564:
! 7565: <p>Then, the same procedure is followed for translation rules for attributes
! 7566: of the element.</p>
! 7567:
! 7568: <p>Finally, the translator applies rules for the element which must be applied
1.1 cvs 7569: after translation of the element's content. These rules are applied in the
7570: order that they appear in the translation schema. When the translation of an
7571: element is done, the translator procedes to translate the following
1.18 cvs 7572: element.</p>
1.30 ! cvs 7573:
! 7574: <p>This order can be changed with the <tt>Attributes</tt> and
1.18 cvs 7575: <tt>Presentation</tt> options of the <a href="#sectc5210"><tt>Create</tt>
7576: rule</a>.</p>
7577: </div>
1.1 cvs 7578:
1.18 cvs 7579: <div class="subsection">
1.30 ! cvs 7580: <h3><a name="sectc5223">Translation of logical attributes</a></h3>
1.1 cvs 7581:
1.30 ! cvs 7582: <p>After the rules for the element types, the translation schema defines rules
1.18 cvs 7583: for attribute values. This section begins with the <tt>ATTRIBUTES</tt>
1.1 cvs 7584: keyword and is composed of a sequence of rule blocks each preceded by an
1.18 cvs 7585: attribute name and an optional value or value range.</p>
1.30 ! cvs 7586:
! 7587: <p>If the attribute's name appears alone before the rule block, the rule are
1.1 cvs 7588: applied to all element which have the attribute, no matter what value the
7589: attribute has. In this case, the attribute name is followed by a colon before
1.18 cvs 7590: the beginning of the rule block.</p>
1.30 ! cvs 7591:
! 7592: <p>The attribute's name can be followed by the name of an element type between
1.1 cvs 7593: parentheses. This says, as in presentation schemas, that the rule block which
7594: follows applies not to the element which has the attribute, but to its
1.18 cvs 7595: descendants of the type indicated between the parentheses.</p>
1.30 ! cvs 7596:
! 7597: <p>If values are given after the attribute name (or after the name of the
! 7598: element type), the rules are applied only when the attribute has the indicated
! 7599: values. The same attribute can appear several times, with different values and
1.1 cvs 7600: different translation rules. Attribute values are indicated in the same way
1.18 cvs 7601: as in <a href="#sectc528">conditions</a> and are followed by a colon before
7602: the block of rules.</p>
1.30 ! cvs 7603:
! 7604: <p>The rule block associated with an attribute is either a simple rule or a
1.18 cvs 7605: sequence of rules delimited by the <tt>BEGIN</tt> and <tt>END</tt> keywords.
7606: Note that rules associated with attribute values cannot be conditional.</p>
1.30 ! cvs 7607:
! 7608: <p>Translation rules are not required for all attributes (or their values)
1.1 cvs 7609: defined in a structure schema. Only those attributes for which a particular
7610: action must be performed by the translator must have such rules. The rules
1.18 cvs 7611: that can be used are those described above, from <a
7612: href="#sectc5210"><tt>Create</tt></a> to <a
7613: href="#sectc5218"><tt>NoTranslation</tt></a>.</p>
1.30 ! cvs 7614: <pre> AttrSeq = TransAttr < TransAttr > .
1.1 cvs 7615: TransAttr = AttrID [ '(' ElemID ')' ]
7616: [ RelatAttr ] ':' RuleSeq .
7617: AttrID = NAME .
1.18 cvs 7618: ElemID = NAME .</pre>
1.30 ! cvs 7619:
1.18 cvs 7620: <blockquote class="example">
1.30 ! cvs 7621: <p><strong>Example:</strong></p>
! 7622:
! 7623: <p>The structure defined the ``Language'' attribute which can take the
! 7624: values ``French'' and ``English''. To have the French parts of the original
! 7625: document removed and prevent the translation of the leaves of the English
! 7626: parts, the following rules would be used:</p>
! 7627: <pre>ATTRIBUTES
1.1 cvs 7628: Language=French :
7629: Remove;
7630: Language=English :
1.18 cvs 7631: NoTranslation;</pre>
7632: </blockquote>
7633: </div>
1.1 cvs 7634:
1.18 cvs 7635: <div class="subsection">
1.30 ! cvs 7636: <h3><a name="sectc5224">Translation of specific presentations</a></h3>
1.1 cvs 7637:
1.30 ! cvs 7638: <p>After the rules for attributes, the translation schema defines rules for
! 7639: the specific presentation. This section begins with the <tt>PRESENTATION</tt>
1.1 cvs 7640: keyword and is composed of a sequence of translation rule blocks each preceded
7641: by a presentation rule name, optionally accompanied by a part which depends on
1.18 cvs 7642: the particular presentation rule.</p>
1.30 ! cvs 7643:
! 7644: <p>Each of these translation rule blocks is applied when the translator
! 7645: operates on an element which has a specific presentation rule of the type
! 7646: indicated at the head of the block. Depending on the type of the specific
! 7647: presentation rule, it is possible to specify values of the presentation rule
! 7648: for which the translation rule block should be applied.</p>
! 7649:
! 7650: <p>There are three categories of the presentation rules:</p>
! 7651: <ul>
! 7652: <li>rules taking numeric values: <tt>Size</tt>, <tt>Indent</tt>,
! 7653: <tt>LineSpacing</tt>, <tt>LineWeight</tt>,</li>
! 7654: <li>rules whose values are taken from a predefined list (i.e. whose type is
! 7655: an enumeration): <tt>Adjust</tt>, <tt>Justify</tt>, <tt>Hyphenate,/TT>,
! 7656: <tt>Style</tt>, <tt>Weight</tt>, <tt>Font</tt>, <tt>UnderLine</tt>,
! 7657: <tt>Thickness</tt>, <tt>LineStyle</tt>,</tt></li>
! 7658: <li>rules whose value is a name: <tt>FillPattern</tt>, <tt>Background</tt>,
! 7659: <tt>Foreground</tt>.</li>
1.18 cvs 7660: </ul>
1.30 ! cvs 7661:
! 7662: <p>For presentation rules of the first category, the values which provoke
1.1 cvs 7663: application of the translation rules are indicated in the same manner as for
1.18 cvs 7664: <a href="#relattr">numeric attributes</a>. This can be either a unique value
1.1 cvs 7665: or range of values. For a unique value, the value (an integer) is simply
7666: preceded by an equals sign. Value ranges can be specified in one of three
1.18 cvs 7667: ways:</p>
7668: <ul>
1.30 ! cvs 7669: <li>all values less than a given value (this value is preceded by a ``less
! 7670: than'' sign '<tt><</tt>'),</li>
! 7671: <li>all values greater than a given value (this value is preceded by a`
! 7672: `greater than'' sign '<tt>></tt>'),</li>
! 7673: <li>all values falling in an interval, bounds included. The range of values
! 7674: is then specified <tt>IN [</tt>Minimum<tt>..</tt>Maximum<tt>]</tt>, where
! 7675: Minimum and Maximum are integers.</li>
1.18 cvs 7676: </ul>
1.30 ! cvs 7677:
! 7678: <p>All numeric values can be negative, in which case the integer is preceded
! 7679: by a minus sign. All values must be given in typographers points.</p>
! 7680:
! 7681: <p>For presentation rules whose values are taken from a predefined list, the
1.1 cvs 7682: value which provokes application of the translation rules is simply indicated
1.18 cvs 7683: by the equals sign followed by the name of the value.</p>
1.30 ! cvs 7684:
! 7685: <p>For presentation rules whose values are names, the value which provokes the
1.1 cvs 7686: application of translation rules is simply indicated by the equals sign
7687: followed by the name of the value. The names of the fill patterns (the
1.18 cvs 7688: <tt>FillPattern</tt> rule) and of the colors (the <tt>Foreground</tt> and
7689: <tt>Background</tt> rules) used in Thot are the same as in the P language.</p>
1.30 ! cvs 7690: <pre> PresSeq = PresTrans < PresTrans > .
1.1 cvs 7691: PresTrans = PresRule ':' RuleSeq .
7692: PresRule = 'Size' [ PresRelation ] /
7693: 'Indent' [ PresRelation ] /
7694: 'LineSpacing' [ PresRelation ] /
7695: 'Adjust' [ '=' AdjustVal ] /
7696: 'Justify' [ '=' BoolVal ] /
7697: 'Hyphenate' [ '=' BoolVal ] /
7698: 'Style' [ '=' StyleVal ] /
1.24 cvs 7699: 'Weight' [ '=' WeightVal ] /
1.1 cvs 7700: 'Font' [ '=' FontVal ] /
7701: 'UnderLine' [ '=' UnderLineVal ] /
7702: 'Thickness' [ '=' ThicknessVal ] /
7703: 'LineStyle' [ '=' LineStyleVal ] /
7704: 'LineWeight' [ PresRelation ] /
7705: 'FillPattern' [ '=' Pattern ] /
7706: 'Background' [ '=' Color ] /
7707: 'Foreground' [ '=' Color ] .
7708:
7709: PresRelation = '=' PresValue /
1.30 ! cvs 7710: '>' [ '-' ] PresMinimum /
1.1 cvs 7711: '<' [ '-' ] PresMaximum /
7712: 'IN' '[' [ '-' ] PresIntervalMin '..'
7713: [ '-' ] PresIntervalMax ']' .
7714: AdjustVal = 'Left' / 'Right' / 'VMiddle' /
7715: 'LeftWithDots' .
7716: BoolVal = 'Yes' / 'No' .
1.24 cvs 7717: StyleVal = 'Roman' / 'Italics' / 'Oblique' .
7718: WeightVal = 'Normal' / 'Bold' .
1.1 cvs 7719: FontVal = 'Times' / 'Helvetica' / 'Courier' .
7720: UnderLineVal = 'NoUnderline' / 'UnderLined' /
7721: 'OverLined' / 'CrossedOut' .
7722: ThicknessVal = 'Thick' / 'Thin' .
1.6 cvs 7723: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
1.1 cvs 7724: Pattern = NAME .
7725: Color = NAME .
7726: PresMinimum = NUMBER .
7727: PresMaximum = NUMBER .
7728: PresIntervalMin= NUMBER .
7729: PresIntervalMax= NUMBER .
7730: PresValue = [ '-' ] PresVal .
1.18 cvs 7731: PresVal = NUMBER .</pre>
1.30 ! cvs 7732:
! 7733: <p>The <a name="prestransl">translation rules associated with specific
1.18 cvs 7734: presentation rules</a> can use the value of the specific presentation rule
1.1 cvs 7735: that causes them to be applied. This behavior is designated by the keyword
1.18 cvs 7736: <tt>Value</tt>. For numerically-valued presentation rules, the numeric value
1.1 cvs 7737: is produced. For other presentation rules, the name of the value is
1.18 cvs 7738: produced.</p>
1.30 ! cvs 7739:
! 7740: <p>It should be noted that modifications to the layout of the document's
! 7741: elements that are made using the combination of the control key and a mouse
! 7742: button will have no effect on the translation of the document.</p>
! 7743:
! 7744: <blockquote class="example">
! 7745: <p><strong>Example:</strong></p>
! 7746:
! 7747: <p>Suppose that it is desirable to use the same font sizes as in the
! 7748: specific presentation, but the font size must be between 10 and 18
! 7749: typographer's points. If font size is set in the translated document by the
! 7750: string <tt>pointsize=n</tt> where <tt>n</tt> is the font size in
! 7751: typographer's points then the following rules will suffice:</p>
! 7752: <pre>PRESENTATION
1.1 cvs 7753: Size < 10 :
7754: Create 'pointsize=10';
7755: Size in [10..18] :
7756: BEGIN
7757: Create 'pointsize=';
7758: Create Value;
7759: END;
1.30 ! cvs 7760: Size > 18 :
1.18 cvs 7761: Create 'pointsize=18';</pre>
7762: </blockquote>
7763: </div>
1.1 cvs 7764:
1.18 cvs 7765: <div class="subsection">
1.30 ! cvs 7766: <h3><a name="sectc5225">Recoding of characters, symbols and graphics</a></h3>
1.1 cvs 7767:
1.30 ! cvs 7768: <p>The coding of characters, graphical elements and symbols as defined in Thot
1.1 cvs 7769: does not necessarily correspond to what is required by an application to which
7770: a Thot document must be exported. Because of this the translator can recode
7771: these terminal elements of the documents structure. The last sections of a
7772: translation schema are intended for this purpose, each specifying the recoding
1.18 cvs 7773: rules for one type of terminal element.</p>
1.30 ! cvs 7774:
! 7775: <p>The recoding rules for character strings are grouped by alphabets. There is
! 7776: a group of rules for each alphabet of the Thot document that must be
! 7777: translated. Each such group of rules begins with the <tt>TEXTTRANSLATE</tt>
! 7778: keyword, followed by the specification of the alphabet to translate and the
! 7779: recoding rules, between the <tt>BEGIN</tt> and <tt>END</tt> keywords unless
! 7780: there is only one recoding rule for the alphabet. The specification of the
! 7781: alphabet is not required: by default it is assumed to the Latin alphabet (the
! 7782: ISO Latin-1 character set).</p>
! 7783:
! 7784: <p>Each recoding rule is formed by a source string between apostrophes and a
1.1 cvs 7785: target string, also between apostrophes, the two strings being separated by
1.30 ! cvs 7786: the arrow symbol (<tt>-></tt>), formed by the ``minus'' and ``greater
! 7787: than'' characters. The rule is terminated by a semi-colon.</p>
1.18 cvs 7788: <pre> TextTransSeq = [ Alphabet ] TransSeq .
1.1 cvs 7789: Alphabet = NAME .
1.30 ! cvs 7790: TransSeq ='BEGIN' < Translation > 'END' ';' /
1.1 cvs 7791: Translation .
1.30 ! cvs 7792: Translation = Source [ '->' Target ] ';' .
1.1 cvs 7793: Source = STRING .
1.18 cvs 7794: Target = STRING .</pre>
1.30 ! cvs 7795:
! 7796: <p>One such rule signifies that when the source string appears in a text leaf
! 7797: of the document being translated, the translator must replace it, in the
1.1 cvs 7798: translated document, with the target string. The source string and the target
7799: string can have different lengths and the target string can be empty. In this
7800: last case, the translator simply suppresses every occurrence of the source
1.18 cvs 7801: string in the translated document.</p>
1.30 ! cvs 7802:
! 7803: <p>For a given alphabet, the order of the rules is not important and has no
1.1 cvs 7804: significance because the T language compiler reorders the rules in ways that
7805: speed up the translator's work. The total number of recoding rules is limited
1.18 cvs 7806: by the compiler as is the maximum length of the source and target strings.</p>
1.30 ! cvs 7807:
! 7808: <p>The recoding rules for symbols and graphical elements are written in the
! 7809: same manner as the recoding rules for character strings. They are preceded,
1.18 cvs 7810: respectively, by the <tt>SYMBTRANSLATE</tt> and <tt>GRAPHTRANSLATE</tt> and so
1.1 cvs 7811: not require a specification of the alphabet. Their source string is limited to
7812: one character, since, in Thot, each symbol and each graphical element is
7813: represented by a single character. The symbol and graphical element codes are
1.18 cvs 7814: defined along with the <a href="#sect7">non-standard character codes</a>.</p>
1.30 ! cvs 7815:
1.18 cvs 7816: <blockquote class="example">
1.30 ! cvs 7817: <p><strong>Example:</strong></p>
! 7818:
! 7819: <p>In a translation schema producing documents destined for use with the
! 7820: L<sup>A</sup>T<sub><big>E</big></sub>X formatter, the Latin characters``é''
! 7821: (octal code 351 in Thot) and ``č'' (octal code 350 in Thot) must be
! 7822: converted to their representation in
! 7823: L<sup>A</sup>T<sub><big>E</big></sub>X:</p>
! 7824: <pre>TEXTTRANSLATE Latin
1.1 cvs 7825: BEGIN
1.30 ! cvs 7826: '\350' -> '\`{e}'; { e grave }
! 7827: '\351' -> '\''{e}'; { e acute }
1.18 cvs 7828: END;</pre>
7829: </blockquote>
7830: </div>
7831: </div>
7832: <hr>
7833: </div>
1.1 cvs 7834:
1.18 cvs 7835: <div class="chapter">
1.30 ! cvs 7836: <h1><a name="sect6">Language grammars</a></h1>
1.1 cvs 7837:
1.30 ! cvs 7838: <p>This chapter gives the complete grammars of the languages of Thot. The
1.1 cvs 7839: grammars were presented and described in the preceding chapters, which also
7840: specify the semantics of the languages. This section gives only the
1.18 cvs 7841: syntax.</p>
1.1 cvs 7842:
1.18 cvs 7843: <div class="section">
1.30 ! cvs 7844: <h2><a name="sectb61">The M meta-language</a></h2>
1.1 cvs 7845:
1.30 ! cvs 7846: <p>The language grammars are all expressed in the same formalism, the M
1.18 cvs 7847: meta-language, which is defined in this section.</p>
7848: <pre>{ Any text between braces is a comment. }
1.30 ! cvs 7849: Grammar = Rule < Rule > 'END' .
! 7850: { The < and > signs indicate zero }
1.1 cvs 7851: { or more repetitions. }
7852: { END marks the end of the grammar. }
7853: Rule = Ident '=' RightPart '.' .
7854: { The period indicates the end of a rule }
7855: RightPart = RtTerminal / RtIntermed .
7856: { The slash indicates a choice }
7857: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
7858: { Right part of a terminal rule }
1.30 ! cvs 7859: RtIntermed = Possibility < '/' Possibility > .
1.1 cvs 7860: { Right part of an intermediate rule }
1.30 ! cvs 7861: Possibility = ElemOpt < ElemOpt > .
! 7862: ElemOpt = Element / '[' Element < Element > ']' /
! 7863: '<' Element < Element > '>' .
1.1 cvs 7864: { Brackets delimit optional parts }
7865: Element = Ident / KeyWord .
7866: Ident = NAME .
7867: { Identifier, sequence of characters
7868: KeyWord = STRING .
7869: { Character string delimited by apostrophes }
1.18 cvs 7870: END</pre>
7871: </div>
1.1 cvs 7872:
1.18 cvs 7873: <div class="section">
1.30 ! cvs 7874: <h2><a name="sectb62">The S language</a></h2>
1.1 cvs 7875:
1.30 ! cvs 7876: <p>The S language is used to write structure schemas, which contain the
! 7877: generic logical structures of document and object classes. It is described
! 7878: here in the M meta-language.</p>
1.18 cvs 7879: <pre>StructSchema = 'STRUCTURE' [ 'EXTENSION' ] ElemID ';'
1.1 cvs 7880: 'DEFPRES' PresID ';'
7881: [ 'ATTR' AttrSeq ]
7882: [ 'PARAM' RulesSeq ]
7883: [ 'STRUCT' RulesSeq ]
7884: [ 'EXTENS' ExtensRuleSeq ]
7885: [ 'ASSOC' RulesSeq ]
7886: [ 'UNITS' RulesSeq ]
7887: [ 'EXPORT' SkeletonSeq ]
7888: [ 'EXCEPT' ExceptSeq ]
7889: 'END' .
7890:
7891: ElemID = NAME .
7892: PresID = NAME .
7893:
1.30 ! cvs 7894: AttrSeq = Attribute < Attribute > .
1.1 cvs 7895: Attribute = AttrID '=' AttrType ';' .
7896: AttrType = 'INTEGER' / 'TEXT' /
7897: 'REFERENCE' '(' RefType ')' /
7898: ValueSeq .
7899: RefType = 'ANY' /
7900: [ FirstSec ] ElemID [ ExtStruct ] .
1.30 ! cvs 7901: ValueSeq = AttrVal < ',' AttrVal > .
1.1 cvs 7902: AttrID = NAME .
7903: FirstSec = 'First' / 'Second' .
7904: ExtStruct = '(' ElemID ')' .
7905: AttrVal = NAME .
7906:
1.30 ! cvs 7907: RulesSeq = Rule < Rule > .
1.1 cvs 7908: Rule = ElemID [ LocAttrSeq ] '='
7909: DefWithAttr ';' .
7910: LocAttrSeq = '(' 'ATTR' LocalAttr
1.30 ! cvs 7911: < ';' LocalAttr > ')' .
1.1 cvs 7912: LocalAttr = [ '!' ] AttrID [ '=' AttrType ] .
7913: DefWithAttr = Definition
7914: [ '+' '(' ExtensionSeq ')' ]
7915: [ '-' '(' RestrictSeq ')' ]
7916: [ 'WITH' FixedAttrSeq ] .
1.30 ! cvs 7917: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1.1 cvs 7918: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
7919: 'SYMBOL' / 'PICTURE' .
1.30 ! cvs 7920: RestrictSeq = RestrictElem < ',' RestrictElem > .
1.1 cvs 7921: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
7922: 'SYMBOL' / 'PICTURE' .
1.30 ! cvs 7923: FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 7924: FixedAttr = AttrID [ FixedOrModifVal ] .
7925: FixedOrModifVal= [ '?' ] '=' FixedValue .
7926: FixedValue = [ '-' ] NumValue / TextValue / AttrVal .
7927: NumValue = NUMBER .
7928: TextValue = STRING .
7929:
7930: Definition = BaseType [ LocAttrSeq ] / Constr /
7931: Element .
7932: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' /
7933: 'PICTURE' / 'UNIT' / 'NATURE' .
7934: Element = ElemID [ ExtOrDef ] .
7935: ExtOrDef = 'EXTERN' / 'INCLUDED' /
7936: [ LocAttrSeq ] '=' Definition .
7937:
7938: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
7939: '(' DefWithAttr ')' /
7940: 'BEGIN' DefOptSeq 'END' /
7941: 'AGGREGATE' DefOptSeq 'END' /
7942: 'CASE' 'OF' DefSeq 'END' /
7943: 'REFERENCE' '(' RefType ')' /
7944: 'PAIR' .
7945:
7946: min = Integer / '*' .
7947: max = Integer / '*' .
7948: Integer = NUMBER .
7949:
1.30 ! cvs 7950: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.1 cvs 7951: DefOpt = [ '?' ] DefWithAttr .
7952:
1.30 ! cvs 7953: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .
1.1 cvs 7954:
1.30 ! cvs 7955: SkeletonSeq = SkeletonElem < ',' SkeletonElem > ';' .
1.1 cvs 7956: SkeletonElem = ElemID [ 'WITH' Contents ] .
7957: Contents = 'Nothing' / ElemID [ ExtStruct ] .
7958:
1.30 ! cvs 7959: ExceptSeq = Except ';' < Except ';' > .
1.1 cvs 7960: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr ':'
7961: ExcValSeq .
7962: ExcTypeOrAttr = ElemID / AttrID .
1.30 ! cvs 7963: ExcValSeq = ExcValue < ',' ExcValue > .
1.1 cvs 7964: ExcValue = 'NoCut' / 'NoCreate' /
7965: 'NoHMove' / 'NoVMove' / 'NoMove' /
7966: 'NoHResize' / 'NoVResize' / 'NoResize' /
1.18 cvs 7967: 'MoveResize' /
1.1 cvs 7968: 'NewWidth' / 'NewHeight' /
7969: 'NewHPos' / 'NewVPos' /
7970: 'Invisible' / 'NoSelect' /
7971: 'Hidden' / 'ActiveRef' /
7972: 'ImportLine' / 'ImportParagraph' /
1.9 cvs 7973: 'NoPaginate' / 'ParagraphBreak' /
7974: 'HighlightChildren' / 'ExtendedSelection' /
1.29 cvs 7975: 'ReturnCreateNL' / 'ReturnCreateWithin' .
1.1 cvs 7976:
1.30 ! cvs 7977: ExtensRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.1 cvs 7978: ExtensRule = RootOrElem [ LocAttrSeq ]
7979: [ '+' '(' ExtensionSeq ')' ]
7980: [ '-' '(' RestrictSeq ')' ]
7981: [ 'WITH' FixedAttrSeq ] .
7982: RootOrElem = 'Root' / ElemID .
7983:
1.18 cvs 7984: END</pre>
7985: </div>
1.1 cvs 7986:
1.18 cvs 7987: <div class="section">
1.30 ! cvs 7988: <h2><a name="sectb63">The P language</a></h2>
1.1 cvs 7989:
1.30 ! cvs 7990: <p>The P language is used to write presentation schemas, which define the
1.1 cvs 7991: graphical presentation rules to be applied to different classes of documents
1.18 cvs 7992: and objects. It is described here in the M meta-language.</p>
7993: <pre>PresSchema = 'PRESENTATION' ElemID ';'
1.1 cvs 7994: [ 'VIEWS' ViewSeq ]
7995: [ 'PRINT' PrintViewSeq ]
7996: [ 'COUNTERS' CounterSeq ]
7997: [ 'CONST' ConstSeq ]
7998: [ 'VAR' VarSeq ]
7999: [ 'DEFAULT' ViewRuleSeq ]
8000: [ 'BOXES' BoxSeq ]
8001: [ 'RULES' PresentSeq ]
8002: [ 'ATTRIBUTES' PresAttrSeq ]
8003: [ 'TRANSMIT' TransmitSeq ]
8004: 'END' .
8005:
8006: ElemID = NAME .
8007:
8008: ViewSeq = ViewDeclaration
1.30 ! cvs 8009: < ',' ViewDeclaration > ';' .
1.1 cvs 8010: ViewDeclaration = ViewID [ 'EXPORT' ] .
8011: ViewID = NAME .
8012:
1.30 ! cvs 8013: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.1 cvs 8014: PrintView = ViewID / ElemID .
8015:
1.30 ! cvs 8016: CounterSeq = Counter < Counter > .
1.1 cvs 8017: Counter = CounterID ':' CounterFunc ';' .
8018: CounterID = NAME .
8019: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
8020: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.30 ! cvs 8021: SetFunction < SetFunction >
! 8022: AddFunction < AddFunction >
1.1 cvs 8023: [ 'INIT' AttrID ] /
1.16 cvs 8024: 'RLEVEL' 'OF' ElemID .
1.1 cvs 8025: SLevelAsc = [ '-' ] LevelAsc .
8026: LevelAsc = NUMBER .
8027: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
8028: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
8029: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 8030: [ '*' ] ElemID .
1.1 cvs 8031: CounterValue = NUMBER .
8032:
1.30 ! cvs 8033: ConstSeq = Const < Const > .
1.1 cvs 8034: Const = ConstID '=' ConstType ConstValue ';' .
8035: ConstID = NAME .
8036: ConstType = 'Text' [ Alphabet ] / 'Symbol' /
8037: 'Graphics' / 'Picture' .
8038: ConstValue = STRING .
8039: Alphabet = NAME .
8040:
1.30 ! cvs 8041: VarSeq = Variable < Variable > .
1.1 cvs 8042: Variable = VarID ':' FunctionSeq ';' .
8043: VarID = NAME .
1.30 ! cvs 8044: FunctionSeq = Function < Function > .
1.1 cvs 8045: Function = 'DATE' / 'FDATE' /
8046: 'DocName' / 'DirName' /
8047: 'ElemName' / 'AttributeName' /
8048: ConstID / ConstType ConstValue /
8049: AttrID /
8050: 'VALUE' '(' PageAttrCtr ','
8051: CounterStyle ')' .
8052: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
8053: [ MinMax ] CounterID / AttrID .
8054: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
8055: 'Uppercase' / 'Lowercase' .
8056: MinMax = 'MaxRangeVal' / 'MinRangeVal' .
8057:
1.30 ! cvs 8058: BoxSeq = Box < Box > .
1.1 cvs 8059: Box = 'FORWARD' BoxID ';' /
8060: BoxID ':' ViewRuleSeq .
8061: BoxID = NAME .
8062:
1.30 ! cvs 8063: PresentSeq = Present < Present > .
1.1 cvs 8064: Present = [ '*' ] [ FirstSec ] ElemID ':'
8065: ViewRuleSeq .
8066: FirstSec = 'First' / 'Second' .
8067:
1.30 ! cvs 8068: PresAttrSeq = PresAttr < PresAttr > .
1.1 cvs 8069: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
8070: [ AttrRelation ] ':' ViewRuleSeq .
8071: AttrID = NAME .
8072: AttrRelation = '=' AttrVal /
1.30 ! cvs 8073: '>' [ '-' ] MinValue /
1.1 cvs 8074: '<' [ '-' ] MaxValue /
8075: 'IN' '[' [ '-' ] LowerBound '..'
8076: [ '-' ] UpperBound ']' /
8077: 'GREATER' AttrID /
8078: 'EQUAL' AttrID /
8079: 'LESS' AttrID .
8080: AttrVal = [ '-' ] EqualNum / EqualText / AttrValue .
8081: MinValue = NUMBER .
8082: MaxValue = NUMBER .
8083: LowerBound = NUMBER .
8084: UpperBound = NUMBER.
8085: EqualNum = NUMBER .
8086: EqualText = STRING .
8087: AttrValue = NAME .
8088:
1.30 ! cvs 8089: ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 8090: 'END' ';' /
8091: ViewRules / CondRules / Rule .
8092: RulesAndCond = CondRules / Rule .
8093: ViewRules = 'IN' ViewID CondRuleSeq .
1.30 ! cvs 8094: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
1.1 cvs 8095: CondRules / Rule .
1.30 ! cvs 8096: CondRules = CondRule < CondRule >
1.1 cvs 8097: [ 'Otherwise' RuleSeq ] .
8098: CondRule = 'IF' ConditionSeq RuleSeq .
1.30 ! cvs 8099: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' / Rule .
1.1 cvs 8100:
1.30 ! cvs 8101: ConditionSeq = Condition < 'AND' Condition > .
1.6 cvs 8102: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
8103: ConditionElem = 'First' / 'Last' /
8104: [ 'Immediately' ] 'Within' [ NumParent ]
8105: ElemID [ ExtStruct ] /
8106: ElemID /
8107: 'Referred' / 'FirstRef' / 'LastRef' /
8108: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
8109: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
8110: 'UserPage' / 'StartPage' / 'ComputedPage' /
8111: 'Empty' /
8112: '(' [ MinMax ] CounterName CounterCond ')' /
8113: CondPage '(' CounterID ')' .
8114: NumParent = [ GreaterLess ] NParent .
1.30 ! cvs 8115: GreaterLess = '>' / '<' .
1.6 cvs 8116: NParent = NUMBER.
1.30 ! cvs 8117: CounterCond = '<' MaxCtrVal / '>' MinCtrVal /
1.6 cvs 8118: '=' EqCtrVal /
8119: 'IN' '[' ['-'] MinCtrBound '..'
8120: ['-'] MaxCtrBound ']' .
8121: PageCond = 'Even' / 'Odd' / 'One' .
8122: MaxCtrVal = NUMBER .
8123: MinCtrVal = NUMBER .
8124: EqCtrVal = NUMBER .
8125: MaxCtrBound = NUMBER .
8126: MinCtrBound = NUMBER .
1.1 cvs 8127:
8128: Rule = PresParam ';' / PresFunc ';' .
8129: PresParam = 'VertRef' ':' HorizPosition /
8130: 'HorizRef' ':' VertPosition /
8131: 'VertPos' ':' VPos /
8132: 'HorizPos' ':' HPos /
8133: 'Height' ':' Extent /
8134: 'Width' ':' Extent /
8135: 'VertOverflow' ':' Boolean /
8136: 'HorizOverflow' ':' Boolean /
1.26 cvs 8137: 'MarginTop' ':' MarginWidth /
8138: 'MarginRight' ':' MarginWidth /
8139: 'MarginBottom' ':' MarginWidth /
8140: 'MarginLeft' ':' MarginWidth /
8141: 'PaddingTop' ':' PaddingWidth /
8142: 'PaddingRight' ':' PaddingWidth /
8143: 'PaddingBottom' ':' PaddingWidth /
8144: 'PaddingLeft' ':' PaddingWidth /
8145: 'BorderTopWidth' ':' BorderWidth /
8146: 'BorderRightWidth' ':' BorderWidth /
8147: 'BorderBottomWidth' ':' BorderWidth /
8148: 'BorderLeftWidth' ':' BorderWidth /
8149: 'BorderTopColor' ':' BorderColor /
8150: 'BorderRightColor' ':' BorderColor /
8151: 'BorderBottomColor' ':' BorderColor /
8152: 'BorderLeftColor' ':' BorderColor /
8153: 'BorderTopStyle' ':' BorderStyle /
8154: 'BorderRightStyle' ':' BorderStyle /
8155: 'BorderBottomStyle' ':' BorderStyle /
8156: 'BorderLeftStyle' ':' BorderStyle .
1.1 cvs 8157: 'LineSpacing' ':' DistOrInherit /
8158: 'Indent' ':' DistOrInherit /
8159: 'Adjust' ':' AlignOrInherit /
8160: 'Justify' ':' BoolInherit /
8161: 'Hyphenate' ':' BoolInherit /
8162: 'PageBreak' ':' Boolean /
8163: 'LineBreak' ':' Boolean /
8164: 'InLine' ':' Boolean /
8165: 'NoBreak1' ':' AbsDist /
8166: 'NoBreak2' ':' AbsDist /
8167: 'Gather' ':' Boolean /
8168: 'Visibility' ':' NumberInherit /
8169: 'Size' ':' SizeInherit /
8170: 'Font' ':' NameInherit /
8171: 'Style' ':' StyleInherit /
1.23 cvs 8172: 'Weight' ':' WeightInherit /
1.1 cvs 8173: 'Underline' ':' UnderLineInherit /
8174: 'Thickness' ':' ThicknessInherit /
8175: 'Depth' ':' NumberInherit /
8176: 'LineStyle' ':' LineStyleInherit /
8177: 'LineWeight' ':' DistOrInherit /
8178: 'FillPattern' ':' NameInherit /
1.30 ! cvs 8179: 'Background' ':' Color /
! 8180: 'Foreground' ':' Color /
1.1 cvs 8181: 'Content' ':' VarConst .
8182: PresFunc = Creation '(' BoxID ')' /
8183: 'Line' /
8184: 'NoLine' /
8185: 'Page' '(' BoxID ')' /
1.13 cvs 8186: 'Copy' '(' BoxTypeToCopy ')' /
8187: 'ShowBox' /
1.18 cvs 8188: 'BackgroundPicture' ':' FileName /
8189: 'PictureMode' ':' PictMode .
1.1 cvs 8190:
8191: BoxTypeToCopy = BoxID [ ExtStruct ] /
8192: ElemID [ ExtStruct ] .
8193: ExtStruct = '(' ElemID ')' .
8194:
8195: Distance = [ Sign ] AbsDist .
8196: Sign = '+' / '-' .
8197: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
8198: [ Unit ] .
8199: IntegerOrAttr = IntegerPart / AttrID .
8200: IntegerPart = NUMBER .
8201: DecimalPart = NUMBER .
8202: Unit = 'em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
8203: 'pc' / 'px' / '%' .
8204:
8205: HPos = 'nil' / VertAxis '=' HorizPosition
8206: [ 'UserSpecified' ] .
8207: VPos = 'nil' / HorizAxis '=' VertPosition
8208: [ 'UserSpecified' ] .
8209: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
8210: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .
8211:
1.6 cvs 8212: VertPosition = Reference '.' HorizAxis [ Distance ] .
8213: HorizPosition = Reference '.' VertAxis [ Distance ] .
8214: Reference = 'Enclosing' [ BoxTypeNot ] /
8215: 'Enclosed' [ BoxTypeNot ] /
8216: 'Previous' [ BoxTypeNot ] /
8217: 'Next' [ BoxTypeNot ] /
8218: 'Referred' [ BoxTypeNot ] /
8219: 'Creator' /
8220: 'Root' /
8221: '*' /
8222: BoxOrType .
8223: BoxOrType = BoxID /
8224: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 8225: 'AnyElem' / 'AnyBox' /
8226: 'ElemWithAttr' AttrID .
1.6 cvs 8227: BoxTypeNot = [ 'NOT' ] BoxOrType .
8228:
8229: Extent = Reference '.' HeightWidth
8230: [ Relation ] [ 'Min' ] /
8231: AbsDist [ 'UserSpecified' ] [ 'Min' ] /
8232: HPos / VPos .
8233: HeightWidth = 'Height' / 'Width' .
8234: Relation = '*' ExtentAttr '%' / Distance .
8235: ExtentAttr = ExtentVal / AttrID .
8236: ExtentVal = NUMBER .
1.26 cvs 8237:
8238: MarginWidth = InheritParent / 'Auto' / Distance .
8239: PaddingWidth = InheritParent / Distance .
8240: BorderWidth = InheritParent / 'Thin' / 'Medium' / 'Thick' / Distance .
8241: BorderColor = InheritParent / 'Transparent' / 'Foreground' /
8242: ColorName .
8243: BorderStyle = InheritParent /
8244: 'None' / 'Hidden' / 'Dotted' / 'Dashed' / 'Solid' /
8245: 'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
1.27 cvs 8246: InheritParent = 'Enclosing' '=' / 'Creator' '=' .
1.26 cvs 8247: ColorName = NAME .
1.6 cvs 8248:
8249: Inheritance = Kinship InheritedValue .
8250: Kinship = 'Enclosing' / 'GrandFather'/ 'Enclosed' /
8251: 'Previous' / 'Creator' .
8252: InheritedValue = '+' PosIntAttr [ 'Max' maximumA ] /
8253: '-' NegIntAttr [ 'Min' minimumA ] /
8254: '=' .
8255: PosIntAttr = PosInt / AttrID .
8256: PosInt = NUMBER .
8257: NegIntAttr = NegInt / AttrID .
8258: NegInt = NUMBER .
8259: maximumA = maximum / AttrID .
8260: maximum = NUMBER .
8261: minimumA = minimum / AttrID .
8262: minimum = NUMBER .
8263:
8264: AlignOrInherit = Kinship '=' / Alignment .
8265: Alignment = 'Left' / 'Right' / 'VMiddle' /
8266: 'LeftWithDots' .
1.1 cvs 8267:
1.6 cvs 8268: DistOrInherit = Kinship InheritedDist / Distance .
8269: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .
1.1 cvs 8270:
1.6 cvs 8271: BoolInherit = Boolean / Kinship '=' .
8272: Boolean = 'Yes' / 'No' .
1.1 cvs 8273:
1.6 cvs 8274: NumberInherit = Integer / AttrID / Inheritance .
8275: Integer = NUMBER .
1.1 cvs 8276:
8277: LineStyleInherit= Kinship '=' / 'Solid' / 'Dashed' /
8278: 'Dotted' .
8279:
1.6 cvs 8280: SizeInherit = SizeAttr [ 'pt' ] / Kinship InheritedSize .
8281: InheritedSize = '+' SizeAttr [ 'pt' ]
8282: [ 'Max' MaxSizeAttr ] /
8283: '-' SizeAttr [ 'pt' ]
8284: [ 'Min' MinSizeAttr ] /
1.22 cvs 8285: '*' PercentSizeAttr '%' /
1.6 cvs 8286: '=' .
8287: SizeAttr = Size / AttrID .
8288: Size = NUMBER .
8289: MaxSizeAttr = MaxSize / AttrID .
8290: MaxSize = NUMBER .
8291: MinSizeAttr = MinSize / AttrID .
8292: MinSize = NUMBER .
1.22 cvs 8293: PercentSizeAttr = PercentSize / AttrID .
8294: PercentSize = NUMBER .
1.6 cvs 8295:
8296: NameInherit = Kinship '=' / FontName .
8297: FontName = NAME .
1.30 ! cvs 8298: Color = 'Transparent' / Kinship '=' / FontName .
1.6 cvs 8299: StyleInherit = Kinship '=' /
1.23 cvs 8300: 'Roman' / 'Italics' / 'Oblique' .
8301: WeightInherit = Kinship '=' /
8302: 'Normal' / 'Bold' .
1.1 cvs 8303: UnderLineInherit= Kinship '=' /
1.6 cvs 8304: 'NoUnderline' / 'Underlined' /
8305: 'Overlined' / 'CrossedOut' .
1.1 cvs 8306: ThicknessInherit= Kinship '=' / 'Thick' / 'Thin' .
1.13 cvs 8307:
8308: FileName = STRING .
8309: PictMode = 'NormalSize' / 'Scale' /
8310: 'RepeatXY' / 'RepeatX' / 'RepeatY' .
1.1 cvs 8311:
1.6 cvs 8312: VarConst = ConstID / ConstType ConstValue /
8313: VarID / '(' FunctionSeq ')' /
8314: ElemID .
8315:
8316: Creation = Create [ 'Repeated' ] .
8317: Create = 'CreateFirst' / 'CreateLast' /
8318: 'CreateBefore' / 'CreateAfter' /
8319: 'CreateEnclosing' .
8320:
1.30 ! cvs 8321: TransmitSeq = Transmit < Transmit > .
1.6 cvs 8322: Transmit = TypeOrCounter 'To' ExternAttr
8323: '(' ElemID ')' ';' .
8324: TypeOrCounter = CounterID / ElemID .
8325: ExternAttr = NAME .
1.1 cvs 8326:
1.18 cvs 8327: END</pre>
8328: </div>
1.1 cvs 8329:
1.18 cvs 8330: <div class="section">
8331: <h2><a name="sectb64">The T language</a></h2>
8332: <pre>TransSchema = 'TRANSLATION' ElemID ';'
1.1 cvs 8333: [ 'LINELENGTH' LineLength ';' ]
8334: [ 'LINEEND' CHARACTER ';' ]
8335: [ 'LINEENDINSERT' STRING ';' ]
8336: [ 'BUFFERS' BufferSeq ]
8337: [ 'COUNTERS' CounterSeq ]
8338: [ 'CONST' ConstSeq ]
8339: [ 'VAR' VariableSeq ]
8340: 'RULES' ElemSeq
8341: [ 'ATTRIBUTES' AttrSeq ]
8342: [ 'PRESENTATION' PresSeq ]
1.30 ! cvs 8343: < 'TEXTTRANSLATE' TextTransSeq >
1.1 cvs 8344: [ 'SYMBTRANSLATE' TransSeq ]
8345: [ 'GRAPHTRANSLATE' TransSeq ]
8346: 'END' .
8347:
8348: LineLength = NUMBER .
8349:
1.30 ! cvs 8350: BufferSeq = Buffer < Buffer > .
1.1 cvs 8351: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
8352: BufferID = NAME .
8353:
1.30 ! cvs 8354: CounterSeq = Counter < Counter > .
1.1 cvs 8355: Counter = CounterID [ ':' CounterFunc ] ';' .
8356: CounterID = NAME .
8357: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
8358: [ 'Init' AttrID ] /
8359: 'Rlevel' 'of' ElemID /
8360: 'Set' InitValue 'On' ElemID
8361: 'Add' Increment 'On' ElemID
8362: [ 'Init' AttrID ] .
8363: SLevelAsc = [ '-' ] LevelAsc .
8364: LevelAsc = NUMBER .
8365: InitValue = NUMBER .
8366: Increment = NUMBER .
8367: ElemID = NAME .
8368: AttrID = NAME .
8369:
1.30 ! cvs 8370: ConstSeq = Const < Const > .
1.1 cvs 8371: Const = ConstID '=' ConstValue ';' .
8372: ConstID = NAME .
8373: ConstValue = STRING .
8374:
1.30 ! cvs 8375: VariableSeq = Variable < Variable > .
! 8376: Variable = VarID ':' Function < Function > ';' .
1.1 cvs 8377: VarID = NAME .
8378: Function = 'Value' '(' CounterID [ ':' Length ]
8379: [ ',' CounterStyle ] ')' /
8380: 'FileDir' / 'FileName' / 'Extension' /
8381: 'DocumentName' / 'DocumentDir' /
8382: ConstID / CharString /
8383: BufferID / AttrID .
8384: Length = NUMBER .
8385: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
8386: 'Uppercase' / 'Lowercase' .
8387: CharString = STRING .
8388:
1.30 ! cvs 8389: ElemSeq = TransType < TransType > .
1.1 cvs 8390: TransType = [ FirstSec ] ElemID ':' RuleSeq .
8391: FirstSec = 'First' / 'Second' .
1.30 ! cvs 8392: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
1.1 cvs 8393: Rule = SimpleRule / ConditionBlock .
8394: ConditionBlock= 'IF' ConditionSeq SimpleRuleSeq .
1.30 ! cvs 8395: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.1 cvs 8396: SimpleRule .
8397:
8398: ConditionSeq = Condition [ 'AND' Condition ] .
8399: Condition = [ 'NOT' ] [ 'Target' ] Cond .
8400: Cond = CondElem / CondAscend .
8401: CondElem = 'FirstRef' / 'LastRef' /
8402: 'ExternalRef' /
8403: 'Defined' /
8404: 'Alphabet' '=' Alphabet /
8405: 'ComputedPage' / 'StartPage' /
8406: 'UserPage' / 'ReminderPage' /
8407: 'Empty' /
1.18 cvs 8408: ElemID /
1.1 cvs 8409: 'FirstAttr' / 'LastAttr' .
8410: CondAscend = [ Ascend ] CondOnAscend .
8411: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
8412: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
8413: CondRelLevel = NUMBER .
8414: CondOnAscend = 'First' / 'Last' /
8415: 'Referred' /
8416: [ 'Immediately' ] 'Within' [ NumParent ]
8417: ElemID [ ExtStruct ] /
8418: 'Attributes' /
8419: AttrID [ RelatAttr ] /
8420: 'Presentation' /
8421: PresRule /
8422: 'Comment' .
8423: NumParent = [ GreaterLess ] NParent .
1.30 ! cvs 8424: GreaterLess = '>' / '<' .
1.1 cvs 8425: NParent = NUMBER.
8426: Alphabet = NAME .
8427: RelatAttr = '=' Value /
1.30 ! cvs 8428: '>' [ '-' ] Minimum /
1.1 cvs 8429: '<' [ '-' ] Maximum /
8430: 'IN' '[' [ '-' ] MinInterval '..'
8431: [ '-' ] MaxInterval ']' .
8432: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
8433: Minimum = NUMBER .
8434: Maximum = NUMBER .
8435: MinInterval = NUMBER .
8436: MaxInterval = NUMBER .
8437: IntegerVal = NUMBER .
8438: TextVal = STRING .
8439: AttrValue = NAME .
8440:
8441: SimpleRule = 'Create' [ 'IN' VarID ] Object
8442: [ Position ] ';' /
8443: 'Write' Object [ Position ] ';' /
8444: 'Read' BufferID [ Position ] ';' /
8445: 'Include' File [ Position ] ';' /
1.6 cvs 8446: 'Get' [ RelPosition ] ElemID
8447: [ ExtStruct ]
8448: [ Position ] ';' /
1.1 cvs 8449: 'Copy' [ RelPosition ] ElemID
8450: [ ExtStruct ]
8451: [ Position ] ';' /
8452: 'Use' TrSchema [ 'For' ElemID ] ';' /
8453: 'Remove' ';' /
8454: 'NoTranslation' ';' /
8455: 'NoLineBreak' ';' /
8456: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 8457: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 8458: 'Set' CounterID InitValue [ Position ] ';' /
8459: 'Add' CounterID Increment [ Position ] ';' /
1.25 cvs 8460: 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .
1.10 cvs 8461:
1.25 cvs 8462: Indent = 'Suspend' / 'Resume' / [ IndentSign ] IndentValue .
1.10 cvs 8463: IndentSign = '+' / '-' .
8464: IndentValue = NUMBER .
1.1 cvs 8465:
8466: Object = ConstID / CharString /
8467: BufferID /
8468: VarID /
1.30 ! cvs 8469: '(' Function < Function > ')' /
1.21 cvs 8470: [ 'Translated' ] AttrID /
1.1 cvs 8471: 'Value' /
8472: 'Content' /
8473: 'Comment' /
8474: 'Attributes' /
8475: 'Presentation' /
8476: 'RefId' /
8477: 'PairId' /
8478: 'FileDir' / 'FileName' / 'Extension' /
8479: 'DocumentName' / 'DocumentDir' /
8480: [ 'Referred' ] ReferredObject .
8481: Position = 'After' / 'Before' .
8482:
1.6 cvs 8483: ReferredObject= VarID /
8484: ElemID [ ExtStruct ] /
8485: 'RefId' /
8486: 'DocumentName' / 'DocumentDir' .
1.1 cvs 8487:
1.6 cvs 8488: File = FileName / BufferID .
8489: FileName = STRING .
1.1 cvs 8490:
1.6 cvs 8491: RelPosition = 'Included' / 'Referred' .
8492: ExtStruct = '(' ElemID ')' .
1.1 cvs 8493:
1.6 cvs 8494: TrSchema = NAME .
8495:
1.30 ! cvs 8496: AttrSeq = TransAttr < TransAttr > .
1.6 cvs 8497: TransAttr = AttrID [ '(' ElemID ')' ]
8498: [ RelatAttr ] ':' RuleSeq .
8499:
1.30 ! cvs 8500: PresSeq = PresTrans < PresTrans > .
1.6 cvs 8501: PresTrans = PresRule ':' RuleSeq .
8502: PresRule = 'Size' [ PresRelation ] /
8503: 'Indent' [ PresRelation ] /
8504: 'LineSpacing' [ PresRelation ] /
8505: 'Adjust' [ '=' AdjustVal ] /
8506: 'Justify' [ '=' BoolVal ] /
8507: 'Hyphenate' [ '=' BoolVal ] /
8508: 'Style' [ '=' StyleVal ] /
1.24 cvs 8509: 'Weight' [ '=' WeightVal ] /
1.6 cvs 8510: 'Font' [ '=' FontVal ] /
8511: 'UnderLine' [ '=' UnderLineVal ] /
8512: 'Thickness' [ '=' ThicknessVal ] /
8513: 'LineStyle' [ '=' LineStyleVal ] /
8514: 'LineWeight' [ PresRelation ] /
8515: 'FillPattern' [ '=' Pattern ] /
8516: 'Background' [ '=' Color ] /
8517: 'Foreground' [ '=' Color ] .
8518:
8519: PresRelation = '=' PresValue /
1.30 ! cvs 8520: '>' [ '-' ] PresMinimum /
1.6 cvs 8521: '<' [ '-' ] PresMaximum /
8522: 'IN' '[' [ '-' ] PresIntervalMin '..'
8523: [ '-' ] PresIntervalMax ']' .
8524: AdjustVal = 'Left' / 'Right' / 'VMiddle' /
8525: 'LeftWithDots' .
8526: BoolVal = 'Yes' / 'No' .
1.24 cvs 8527: StyleVal = 'Roman' / 'Italics' / 'Oblique' .
8528: WeightVal = 'Normal' / 'Bold' .
1.6 cvs 8529: FontVal = 'Times' / 'Helvetica' / 'Courier' .
8530: UnderLineVal = 'NoUnderline' / 'UnderLined' /
8531: 'OverLined' / 'CrossedOut' .
8532: ThicknessVal = 'Thick' / 'Thin' .
8533: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
8534: Pattern = NAME .
8535: Color = NAME .
8536: PresMinimum = NUMBER .
8537: PresMaximum = NUMBER .
1.1 cvs 8538: PresIntervalMin= NUMBER .
8539: PresIntervalMax= NUMBER .
1.6 cvs 8540: PresValue = [ '-' ] PresVal .
8541: PresVal = NUMBER .
1.1 cvs 8542:
1.6 cvs 8543: TextTransSeq = [ Alphabet ] TransSeq .
8544: Alphabet = NAME .
1.30 ! cvs 8545: TransSeq = 'BEGIN' < Translation > 'END' ';' /
1.6 cvs 8546: Translation .
1.30 ! cvs 8547: Translation = Source [ '->' Target ] ';' .
1.6 cvs 8548: Source = STRING .
1.18 cvs 8549: Target = STRING .</pre>
8550: </div>
8551: <hr>
8552: </div>
1.1 cvs 8553:
1.18 cvs 8554: <div class="chapter">
8555: <h1><a name="sect7">Character coding</a></h1>
1.1 cvs 8556:
1.18 cvs 8557: <div class="section">
1.30 ! cvs 8558: <h2><a name="sectb71">Characters</a></h2>
1.1 cvs 8559:
1.30 ! cvs 8560: <p>The characters of the Latin alphabet follow the encoding defined in the ISO
1.5 cvs 8561: 8859-1 (ISO Latin-1) standard. The characters of the Greek alphabet follow
1.18 cvs 8562: the encoding defined by Adobe for its Symbol font (Adobe FontSpecific).</p>
1.30 ! cvs 8563:
! 8564: <p>Characters whose octal code is greater than 0200 are written in the form of
1.1 cvs 8565: their octal code preceded by a backslash character (``\''). For example, the
1.30 ! cvs 8566: French word 'Résumé' is written <tt>R\351sum\351</tt>.</p>
! 8567:
! 8568: <p>To the ISO 8859-1 encoding four characters with the following codes have
! 8569: been added:<br>
1.18 cvs 8570: <tt>212</tt>: line break<br>
8571: <tt>240</tt>: sticky space<br>
8572: <tt>201</tt>: thin space<br>
8573: <tt>202</tt>: en space</p>
1.30 ! cvs 8574:
! 8575: <p>The <tt>212</tt> character is a ``line break'' character which forces a
! 8576: line break. The <tt>240</tt> character is a ``sticky space'', which cannot be
1.18 cvs 8577: replaced by a line break.</p>
8578: </div>
1.1 cvs 8579:
1.18 cvs 8580: <div class="section">
1.30 ! cvs 8581: <h2><a name="sectb72">Symbols</a></h2>
1.1 cvs 8582:
1.30 ! cvs 8583: <p>The table below gives the codes for the symbols of Thot. Symbols can be
! 8584: used in presentation schemas constants and in transcoding rules of translation
1.18 cvs 8585: schemas. Each symbol is represented by a single character.</p>
8586: <ul>
1.30 ! cvs 8587: <li><tt>r</tt>: a radical</li>
! 8588: <li><tt>i</tt>: a simple integral</li>
! 8589: <li><tt>c</tt>: a curvilinear integral</li>
! 8590: <li><tt>d</tt>: a double integral</li>
! 8591: <li><tt>t</tt>: a triple integral</li>
! 8592: <li><tt>S</tt>: the summation symbol</li>
! 8593: <li><tt>P</tt>: the product symbol</li>
! 8594: <li><tt>U</tt>: the union symbol</li>
! 8595: <li><tt>I</tt>: the intersection symbol</li>
! 8596: <li><tt>></tt>: a right arrow</li>
! 8597: <li><tt><</tt>: a left arrow</li>
! 8598: <li><tt>^</tt>: an up arrow</li>
! 8599: <li><tt>V</tt>: a down arrow</li>
! 8600: <li><tt>(</tt>: an opening parenthesis</li>
! 8601: <li><tt>)</tt>: a closing parenthesis</li>
! 8602: <li><tt>{</tt>: an opening brace</li>
! 8603: <li><tt>}</tt>: a closing brace</li>
! 8604: <li><tt>[</tt>: an opening bracket</li>
! 8605: <li><tt>]</tt>: a closing bracket</li>
1.18 cvs 8606: </ul>
8607: </div>
1.1 cvs 8608:
1.18 cvs 8609: <div class="section">
1.30 ! cvs 8610: <h2><a name="sectb73">Graphical elements</a></h2>
1.1 cvs 8611:
1.30 ! cvs 8612: <p>The table below gives the codes for the graphical elements of Thot. These
1.1 cvs 8613: elements can be used in presentation schemas constants and in transcoding
8614: rules of translation schemas. Each graphical element is represented by a
1.18 cvs 8615: single character.</p>
8616: <ul>
1.30 ! cvs 8617: <li>a: a circle</li>
! 8618: <li><p><tt>A</tt>: an open curve with an arrow head at the end</p>
! 8619: </li>
! 8620: <li><tt>b</tt>: a horizontal line along the lower side of the box</li>
! 8621: <li><tt>B</tt>: an open curve</li>
! 8622: <li><tt>c</tt>: an ellipse inscribed in the box</li>
! 8623: <li><tt>C</tt>: a rectangle with rounded corners</li>
! 8624: <li><tt>D</tt>: an open curve with two arrow heads</li>
! 8625: <li><tt>e</tt>: The northwest/southeast diagonal of the box with an
! 8626: arrowhead at the bottom</li>
! 8627: <li><tt>E</tt>: The southwest/northeast diagonal of the box with an
! 8628: arrowhead at the top</li>
! 8629: <li><tt>F</tt>: an open curve with an arrow head at start</li>
! 8630: <li><tt>g</tt>: a line from the origin of the box to its opposite
! 8631: corner</li>
! 8632: <li><tt>h</tt>: a horizontal line as wide as the box and placed in its
! 8633: middle</li>
! 8634: <li><tt>l</tt>: a vertical line on the left side of the box</li>
! 8635: <li><tt>L</tt>: a lozenge</li>
! 8636: <li><tt>M</tt>: an open broken line with two arrow heads</li>
! 8637: <li><tt>N</tt>: an open broken line with an arrow head at start</li>
! 8638: <li><tt>o</tt>: The southwest/northeast diagonal of the box with an
! 8639: arrowhead at the bottom</li>
! 8640: <li><tt>O</tt>: The northwest/southeast diagonal of the box with an
! 8641: arrowhead at the top</li>
! 8642: <li><tt>p</tt>: a polygon</li>
! 8643: <li><tt>P</tt>: a rectangle with round corners and a horizontal bar at the
! 8644: top</li>
! 8645: <li><tt>Q</tt>: an ellipse with a horizontal bar at the top</li>
! 8646: <li><tt>r</tt>: a vertical line on the right side of the box</li>
! 8647: <li><tt>R</tt>: a rectangle which is the shape of the box</li>
! 8648: <li><tt>s</tt>: a closed curve</li>
! 8649: <li><tt>S</tt>: an open broken line</li>
! 8650: <li><tt>t</tt>: a horizontal line along the upper side of the box</li>
! 8651: <li><tt>U</tt>: an open broken line with an arrow head at the end</li>
! 8652: <li><tt>v</tt>: a vertical line as tall as the box and placed in its
! 8653: middle</li>
! 8654: <li><tt>V</tt>: a down arrow as tall as the box and in its middle</li>
! 8655: <li>w: a segment (2 points)</li>
! 8656: <li><tt>W</tt>: the upper right corner</li>
! 8657: <li>x: a segment (2 points) with an arrow head at the end</li>
! 8658: <li><tt>X</tt>: the lower right corner</li>
! 8659: <li>y: a segment (2 points) with an arrow head at the end</li>
! 8660: <li><tt>Y</tt>: the lower left corner</li>
! 8661: <li>z: a segment (2 points) with an arrow head at the end</li>
! 8662: <li><tt>Z</tt>: the upper left corner</li>
! 8663: <li><tt>space</tt>: a transparent element</li>
! 8664: <li><tt>^</tt>: an up arrow as tall as the box and in its middle</li>
! 8665: <li><tt>></tt>: a right arrow as long as the box's width and in its
! 8666: middle</li>
! 8667: <li><tt>></tt>: a left arrow as long as the box's width and in its
! 8668: middle</li>
! 8669: <li><tt>/</tt>: The southwest/northeast diagonal of the box</li>
! 8670: <li><tt>\</tt>: the northwest/southeast diagonal of the box</li>
1.18 cvs 8671: </ul>
8672: <hr>
8673: </div>
8674: </div>
8675: </body>
8676: </html>
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