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! 2: <html>
! 3: <head>
! 4: <title>
! 5: The Languages of Thot</title>
! 6: </head>
! 7: <body>
! 8:
! 9: <div class="frontmatter" align=center>
! 10:
! 11: <h1>The Languages of Thot</h1>
! 12:
! 13: <h3>Vincent Quint</h3>
! 14:
! 15: <h4>Translated from French by Ethan Munson</h4>
! 16:
! 17: <h4>Version of March, 1998</h4>
! 18: <p>
! 19: © 1996 INRIA</p>
! 20: <hr>
! 21: </div>
! 22:
! 23: <div class="tableofcontents">
! 24:
! 25: <h2><a href="languages.toc.html">Contents</a></h2>
! 26: <ul>
! 27: <li>
! 28: <big><a href="#sect2">The document model of Thot</a></big>
! 29: <ul>
! 30: <li>
! 31: <strong><a href="#sectb21">The logical structure of documents</a></strong>
! 32: <li>
! 33: <strong><a href="#sectb22">Generic and specific structures</a></strong>
! 34: <li>
! 35: <strong><a href="#sectb23">Logical structure and physical
! 36: structure</a></strong>
! 37: <li>
! 38: <strong><a href="#sectb24">Document structures and object
! 39: structures</a></strong>
! 40: </ul>
! 41: <li>
! 42: <big><a href="#sect3">The S language</a></big>
! 43: <ul>
! 44: <li>
! 45: <strong><a href="#sectb31">Document meta-structure</a></strong>
! 46: <ul>
! 47: <li>
! 48: <a href="#sectc311">The basic types</a>
! 49: <li>
! 50: <a href="#sectc312">Constructed elements</a>
! 51: <li>
! 52: <a href="#sectc313">Logical structure constructors</a>
! 53: <ul>
! 54: <li>
! 55: <small><a href="#sectd3131">Aggregate and List</a></small>
! 56: <li>
! 57: <small><a href="#sectd3132">Choice, Schema, and Unit</a></small>
! 58: <li>
! 59: <small><a href="#sectd3133">Reference and Inclusion</a></small>
! 60: <li>
! 61: <small><a href="#sectd3134">Mark pairs</a></small>
! 62: <li>
! 63: <small><a href="#sectd3135">Restrictions and Extensions</a></small>
! 64: <li>
! 65: <small><a href="#sectd3136">Summary</a></small>
! 66: </ul>
! 67: <li>
! 68: <a href="#sectc314">Associated Elements</a>
! 69: <li>
! 70: <a href="#sectc315">Attributes</a>
! 71: <li>
! 72: <a href="#sectc316">Discussion of the model</a>
! 73: </ul>
! 74: <li>
! 75: <strong><a href="#sectb32">The definition language for generic
! 76: structures</a></strong>
! 77: <ul>
! 78: <li>
! 79: <a href="#sectc321">Writing Conventions</a>
! 80: <li>
! 81: <a href="#sectc322">Extension schemas</a>
! 82: <li>
! 83: <a href="#sectc323">The general organization of structure schemas</a>
! 84: <li>
! 85: <a href="#sectc324">The default presentation</a>
! 86: <li>
! 87: <a href="#sectc325">Global Attributes</a>
! 88: <li>
! 89: <a href="#sectc326">Parameters</a>
! 90: <li>
! 91: <a href="#sectc327">Structured elements</a>
! 92: <li>
! 93: <a href="#sectc328">Structure definitions</a>
! 94: <ul>
! 95: <li>
! 96: <small><a href="#sectd3281">List</a></small>
! 97: <li>
! 98: <small><a href="#sectd3282">Aggregate</a></small>
! 99: <li>
! 100: <small><a href="#sectd3283">Choice</a></small>
! 101: <li>
! 102: <small><a href="#sectd3284">Reference</a></small>
! 103: <li>
! 104: <small><a href="#sectd3285">Mark pairs</a></small>
! 105: </ul>
! 106: <li>
! 107: <a href="#sectc329">Imports</a>
! 108: <li>
! 109: <a href="#sectc3210">Extension rules</a>
! 110: <li>
! 111: <a href="#sectc3211">Associated elements</a>
! 112: <li>
! 113: <a href="#sectc3212">Units</a>
! 114: <li>
! 115: <a href="#sectc3213">Skeleton elements</a>
! 116: <li>
! 117: <a href="#sectc3214">Exceptions</a>
! 118: </ul>
! 119: <li>
! 120: <strong><a href="#sectb33">Some examples</a></strong>
! 121: <ul>
! 122: <li>
! 123: <a href="#sectc331">A class of documents: articles</a>
! 124: <li>
! 125: <a href="#sectc332">A class of objects: mathematical formulas</a>
! 126: </ul>
! 127: </ul>
! 128: <li>
! 129: <big><a href="#sect4">The P language</a></big>
! 130: <ul>
! 131: <li>
! 132: <strong><a href="#sectb41">Document presentation</a></strong>
! 133: <ul>
! 134: <li>
! 135: <a href="#sectc411">Two levels of presentation</a>
! 136: <li>
! 137: <a href="#sectc412">Boxes</a>
! 138: <li>
! 139: <a href="#sectc413">Views and visibility</a>
! 140: <li>
! 141: <a href="#sectc414">Pages</a>
! 142: <li>
! 143: <a href="#sectc415">Numbering</a>
! 144: <li>
! 145: <a href="#sectc416">Presentation parameters</a>
! 146: </ul>
! 147: <li>
! 148: <strong><a href="#sectb42">Presentation description language</a></strong>
! 149: <ul>
! 150: <li>
! 151: <a href="#sectc421">The organization of a presentation schema</a>
! 152: <li>
! 153: <a href="#sectc422">Views</a>
! 154: <li>
! 155: <a href="#sectc423">Print Views</a>
! 156: <li>
! 157: <a href="#sectc424">Counters</a>
! 158: <li>
! 159: <a href="#sectc425">Presentation constants</a>
! 160: <li>
! 161: <a href="#sectc426">Variables</a>
! 162: <li>
! 163: <a href="#sectc427">Default presentation rules</a>
! 164: <li>
! 165: <a href="#sectc428">Presentation and page layout boxes</a>
! 166: <li>
! 167: <a href="#sectc429">Presentation of structured elements</a>
! 168: <li>
! 169: <a href="#sectc4210">Logical attribute presentation</a>
! 170: <li>
! 171: <a href="#sectc4212">Value transmission rules</a>
! 172: <li>
! 173: <a href="#sectc4213">Presentation rules</a>
! 174: <li>
! 175: <a href="#sectc4214">Conditions applying to presentation rules</a>
! 176: <ul>
! 177: <li>
! 178: <small><a href="#sectd42141">Conditions based on the logical position of the
! 179: element</a></small>
! 180: <li>
! 181: <small><a href="#sectd42142">Conditions on references</a></small>
! 182: <li>
! 183: <small><a href="#sectd42143">Conditions on logical attributes</a></small>
! 184: <li>
! 185: <small><a href="#sectd42144">Conditions on page breaks</a></small>
! 186: <li>
! 187: <small><a href="#sectd42145">Conditions on the element's content</a></small>
! 188: <li>
! 189: <small><a href="#sectd42146">Conditions on counters</a></small>
! 190: </ul>
! 191: <li>
! 192: <a href="#sectc4215">A presentation rule</a>
! 193: <li>
! 194: <a href="#sectc4216">Box axes</a>
! 195: <li>
! 196: <a href="#sectc4217">Distance units</a>
! 197: <li>
! 198: <a href="#sectc4218">Relative positions</a>
! 199: <li>
! 200: <a href="#sectc4219">Box extents</a>
! 201: <ul>
! 202: <li>
! 203: <small><a href="#sectd42191">Fixed extents</a></small>
! 204: <li>
! 205: <small><a href="#sectd42192">Relative extents</a></small>
! 206: <li>
! 207: <small><a href="#sectd42193">Elastic extents</a></small>
! 208: </ul>
! 209: <li>
! 210: <a href="#sectc4220">Overflow</a>
! 211: <li>
! 212: <a href="#sectc4221">Inheritance</a>
! 213: <li>
! 214: <a href="#sectc4222">Line breaking</a>
! 215: <ul>
! 216: <li>
! 217: <small><a href="#sectd42221">Line spacing</a></small>
! 218: <li>
! 219: <small><a href="#sectd42222">First line indentation</a></small>
! 220: <li>
! 221: <small><a href="#sectd42223">Alignment</a></small>
! 222: <li>
! 223: <small><a href="#sectd42224">Justification</a></small>
! 224: <li>
! 225: <small><a href="#sectd42225">Hyphenation</a></small>
! 226: <li>
! 227: <small><a href="#sectd42226">Avoiding line breaking</a></small>
! 228: </ul>
! 229: <li>
! 230: <a href="#sectc4223">Page breaking and line breaking conditions</a>
! 231: <li>
! 232: <a href="#sectc4224">Visibility</a>
! 233: <li>
! 234: <a href="#sectc4225">Character style parameters</a>
! 235: <ul>
! 236: <li>
! 237: <small><a href="#sectd42251">Character size</a></small>
! 238: <li>
! 239: <small><a href="#sectd42252">Font and character style</a></small>
! 240: <li>
! 241: <small><a href="#sectd42253">Underlining</a></small>
! 242: </ul>
! 243: <li>
! 244: <a href="#sectc4226">Stacking order</a>
! 245: <li>
! 246: <a href="#sectc4227">Line style</a>
! 247: <li>
! 248: <a href="#sectc4228">Line thickness</a>
! 249: <li>
! 250: <a href="#sectc4229">Fill pattern</a>
! 251: <li>
! 252: <a href="#sectc4230">Colors</a>
! 253: <li>
! 254: <a href="#sectc4230a">Background color and border</a>
! 255: <li>
! 256: <a href="#sectc4230b">Background pictures</a>
! 257: <li>
! 258: <a href="#sectc4231">Presentation box content</a>
! 259: <li>
! 260: <a href="#sectc4232">Presentation box creation</a>
! 261: <li>
! 262: <a href="#sectc4233">Page layout</a>
! 263: <li>
! 264: <a href="#sectc4234">Box copies</a>
! 265: </ul>
! 266: </ul>
! 267: <li>
! 268: <big><a href="#sect5">The T language</a></big>
! 269: <ul>
! 270: <li>
! 271: <strong><a href="#sectb51">Document translation</a></strong>
! 272: <ul>
! 273: <li>
! 274: <a href="#sectc511">Translation principles</a>
! 275: <li>
! 276: <a href="#sectc512">Translation procedure</a>
! 277: </ul>
! 278: <li>
! 279: <strong><a href="#sectb52">Translation definition language</a></strong>
! 280: <ul>
! 281: <li>
! 282: <a href="#sectc521">Organization of a translation schema</a>
! 283: <li>
! 284: <a href="#sectc522">Line length</a>
! 285: <li>
! 286: <a href="#sectc523">Buffers</a>
! 287: <li>
! 288: <a href="#sectc524">Counters</a>
! 289: <li>
! 290: <a href="#sectc525">Constants</a>
! 291: <li>
! 292: <a href="#sectc526">Variables</a>
! 293: <li>
! 294: <a href="#sectc527">Translating structure elements</a>
! 295: <li>
! 296: <a href="#sectc528">Conditional rules</a>
! 297: <ul>
! 298: <li>
! 299: <small><a href="#sectd5281">Conditions based on the logical position of the
! 300: element</a></small>
! 301: <li>
! 302: <small><a href="#sectd5282">Conditions on references</a></small>
! 303: <li>
! 304: <small><a href="#sectd5283">Conditions on the parameters</a></small>
! 305: <li>
! 306: <small><a href="#sectd5284">Conditions on the alphabets</a></small>
! 307: <li>
! 308: <small><a href="#sectd5285">Conditions on page breaks</a></small>
! 309: <li>
! 310: <small><a href="#sectd5286">Conditions on the element's content</a></small>
! 311: <li>
! 312: <small><a href="#sectd5287">Conditions on the presence of comments</a></small>
! 313: <li>
! 314: <small><a href="#sectd5288">Conditions on the presence of specific
! 315: presentation rules</a></small>
! 316: <li>
! 317: <small><a href="#sectd5289">Conditions on the presence of logical
! 318: attributes</a></small>
! 319: <li>
! 320: <small><a href="#sectd52810">Conditions on logical attributes</a></small>
! 321: <li>
! 322: <small><a href="#sectd52811">Conditions on specific presentation
! 323: rules</a></small>
! 324: </ul>
! 325: <li>
! 326: <a href="#sectc529">Translation rules</a>
! 327: <li>
! 328: <a href="#sectc5210">The <tt>Create</tt> rule</a>
! 329: <li>
! 330: <a href="#sectc5211">The <tt>Write</tt> rule</a>
! 331: <li>
! 332: <a href="#sectc5212">The <tt>Read</tt> rule</a>
! 333: <li>
! 334: <a href="#sectc5213">The <tt>Include</tt> rule</a>
! 335: <li>
! 336: <a href="#sectc5214">The <tt>Get</tt> rule</a>
! 337: <li>
! 338: <a href="#sectc5215">The <tt>Copy</tt> rule</a>
! 339: <li>
! 340: <a href="#sectc5216">The <tt>Use</tt> rule</a>
! 341: <li>
! 342: <a href="#sectc5217">The <tt>Remove</tt> rule</a>
! 343: <li>
! 344: <a href="#sectc5218">The <tt>NoTranslation</tt> rule</a>
! 345: <li>
! 346: <a href="#sectc5219">The <tt>NoLineBreak</tt> rule</a>
! 347: <li>
! 348: <a href="#sectc5220">The <tt>ChangeMainFile</tt> rule</a>
! 349: <li>
! 350: <a href="#sectc5220a">The <tt>RemoveFile</tt> rule</a>
! 351: <li>
! 352: <a href="#sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a>
! 353: <li>
! 354: <a href="#sectc5221a">The <tt>Indent</tt> rule</a>
! 355: <li>
! 356: <a href="#sectc5222">Rule application order</a>
! 357: <li>
! 358: <a href="#sectc5223">Translation of logical attributes</a>
! 359: <li>
! 360: <a href="#sectc5224">Translation of specific presentations</a>
! 361: <li>
! 362: <a href="#sectc5225">Recoding of characters, symbols and graphics</a>
! 363: </ul>
! 364: </ul>
! 365: <li>
! 366: <big><a href="#sect6">Language grammars</a></big>
! 367: <ul>
! 368: <li>
! 369: <strong><a href="#sectb61">The M meta-language</a></strong>
! 370: <li>
! 371: <strong><a href="#sectb62">The S language</a></strong>
! 372: <li>
! 373: <strong><a href="#sectb63">The P language</a></strong>
! 374: <li>
! 375: <strong><a href="#sectb64">The T language</a></strong>
! 376: </ul>
! 377: <li>
! 378: <big><a href="#sect7">Character coding</a></big>
! 379: <ul>
! 380: <li>
! 381: <strong><a href="#sectb71">Characters</a></strong>
! 382: <li>
! 383: <strong><a href="#sectb72">Symbols</a></strong>
! 384: <li>
! 385: <strong><a href="#sectb73">Graphical elements</a></strong>
! 386: </ul>
! 387: </ul>
! 388: <hr>
! 389: </div>
1.1 cvs 390:
1.18 ! cvs 391: <div class="chapter">
1.1 cvs 392:
1.18 ! cvs 393: <h1><a name="sect2">The document model of Thot</a></h1>
! 394: <p>
1.1 cvs 395: All of the services which Thot provides to the user are based on the system's
396: internal document representation. This representation is itself derived from
397: the document model which underlies Thot. The model is presented here, prior
398: to the description of the languages which permit the generic specification of
1.18 ! cvs 399: documents.</p>
1.1 cvs 400:
1.18 ! cvs 401: <div class="section">
1.1 cvs 402:
1.18 ! cvs 403: <h2><a name="sectb21">The logical structure of documents</a></h2>
! 404: <p>
1.1 cvs 405: The document model of Thot is primarily designed to allow the user to operate
1.5 cvs 406: on those entities which s/he has in mind when s/he works on a document. The
407: model makes no assumptions about the nature of these entities. It is
408: essentially these logical entities, such as paragraphs, sections, chapters,
409: notes, titles, and cross-references which give a document its logical
1.18 ! cvs 410: structure.</p>
! 411: <p>
1.5 cvs 412: Because of this model, the author can divide the document into chapters,
1.1 cvs 413: giving each one a title. The content of these chapters can be further divided
1.2 cvs 414: into sections, subsections, etc. The text is organized into successive
415: paragraphs, according to the content. In the writing phase, the lines, pages,
416: margins, spacing, fonts, and character styles are not very important. In fact,
417: if the system requires documents to be written in these terms, it gets in the
418: way. So, Thot's model is primarily based on the logical aspect of documents.
1.18 ! cvs 419: The creation of a model of this type essentially requires the definition :</p>
! 420: <ul>
! 421: <li>
! 422: of the entities which can appear in the documents,
! 423: <li>
! 424: and the relations between these entities.
! 425: </ul>
! 426: <p>
1.1 cvs 427: The choice of entities to include in the model can be subtle. Some documents
428: require chapters, while others only need various levels of sections. Certain
429: documents contain appendices, others don't. In different documents the same
430: logical entity may go by different names (e.g. ``Conclusion'' and
431: ``Summary''). Certain entities which are absolutely necessary in some
432: documents, such as clauses in a contract or the address of the recipient in a
1.18 ! cvs 433: letter, are useless in most other cases.</p>
! 434: <p>
1.1 cvs 435: The differences between documents result from more than just the entities that
436: appear in them, but also from the relationships between these entities and the
437: ways that they are linked. In certain documents, notes are spread throughout
438: the document, for example at the bottom of the page containing the
439: cross-reference to them, while in other documents they are collected at the
440: end of each chapter or even at the end of the work. As another example, the
441: introduction of some documents can contain many sections, while in other
442: documents, the introduction is restricted to be a short sequence of
1.18 ! cvs 443: paragraphs.</p>
! 444: <p>
1.1 cvs 445: All of this makes it unlikely that a single model can describe any document at
446: a relatively high level. It is obviously tempting to make up a list of widely
447: used entities, such as chapters, sections, paragraphs, and titles, and then
448: map all other entities onto the available choices. In this way, an
449: introduction can be supported as a chapter and a contract clause supported as
450: a paragraph or section. However, in trying to widen the range of usage of
451: certain entities, their meaning can be lost and the power of the model
452: reduced. In addition, while this widening partially solves the problem of
453: choosing entities, it does not solve the problem of their organization: when a
454: chapter must be composed of sections, how does one indicate that an
455: introduction has none when it is merely another chapter? One solution is to
456: include introductions in the list of supported entities. But then, how does
457: one distinguish those introductions which are allowed to have sections from
458: those which are not. Perhaps this could be done by defining two types of
459: introduction. Clearly, this approach risks an infinite expansion of the list
1.18 ! cvs 460: of widely used entities.</p>
! 461: </div>
1.1 cvs 462:
1.18 ! cvs 463: <div class="section">
1.1 cvs 464:
1.18 ! cvs 465: <h2><a name="sectb22">Generic and specific structures</a></h2>
! 466: <p>
1.1 cvs 467: Thus, it is apparently impossible to construct an exhaustive inventory of all
1.2 cvs 468: those entities which are necessary and sufficient to precisely describe any
469: document. It also seems impossible to specify all possible arrangements of
1.18 ! cvs 470: these entities in a document. This is why Thot uses a <em>meta-model</em>
! 471: instead, which permits the description of numerous <em>models</em>, each one
! 472: describing a <em>class</em> of documents.</p>
! 473: <p>
! 474: A <em>class</em> is a set of documents having very similar structure. Thus,
1.1 cvs 475: the collection of research reports published by a laboratory constitutes a
476: class; the set of commercial proposals by the sales department of a company
477: constitutes another class; the set of articles published by a journal
478: constitutes a third class. Clearly, it is not possible to enumerate every
479: possible document class. It is also clear that new document classes must be
1.18 ! cvs 480: created to satisfy new needs and applications.</p>
! 481: <p>
1.1 cvs 482: To give a more rigorous definition of classes, we must introduce the ideas of
1.18 ! cvs 483: <em>generic structure</em> and <em>specific structure</em>. Each document has
! 484: a <em>specific structure</em> which organizes the various parts which comprise
1.1 cvs 485: it. We illustrate this with the help of a simple example comparing two
1.18 ! cvs 486: reports, A and B (<a href="#specstruct">see Figure</a>). The report A contains
1.1 cvs 487: an introduction followed by three chapters and a conclusion. The first
488: chapter contains two sections, the second, three sections. That is the
1.18 ! cvs 489: <em>specific</em> structure of document A. Similarly, the structure of
1.1 cvs 490: document B is: an introduction, two chapters, a conclusion; Chapter 1 has
491: three sections while Chapter 2 has four. The specific structures of these two
1.18 ! cvs 492: documents are thus different.</p>
1.1 cvs 493:
1.18 ! cvs 494: <div class="figure">
! 495: <hr>
! 496: <pre> Report A Report B
1.1 cvs 497: Introduction Introduction
498: Chapter 1 Chapter 1
499: Section 1.1 Section 1.1
500: Section 1.2 Section 1.2
501: Chapter 2 Section 1.3
502: Section 2.1 Chapter 2
503: Section 2.2 Section 2.1
504: Section 2.3 Section 2.2
505: Chapter 3 Section 2.3
506: Conclusion Section 2.4
1.18 ! cvs 507: Conclusion</pre>
! 508: <p align=center>
! 509: <em><a name="specstruct">Two specific structures</a></em></p>
! 510: <hr>
! 511: </div>
! 512: <p>
! 513: The <em>generic structure</em> defines the ways in which specific structures
1.1 cvs 514: can be constructed. It specifies how to generate specific structures. The
515: reports A and B, though different, are constructed in accordance with the same
516: generic structure, which specifies that a report contains an introduction
517: followed by a variable number of chapters and a conclusion, with each chapter
1.18 ! cvs 518: containing a variable number of sections.</p>
! 519: <p>
1.1 cvs 520: There is a one-to-one correspondence between a class and a generic structure:
521: all the documents of a class are constructed in accordance with the same
522: generic structure. Hence the definition of the class: a class is a set of
523: documents whose specific structure is constructed in accordance with the same
1.18 ! cvs 524: generic structure. A class is characterized by its generic structure.</p>
! 525: <p>
1.1 cvs 526: Thus, a generic structure can be considered to be a model at the level which
527: interests us, but only for one class of documents. When the definition is
528: limited to a single class of documents, it is possible to define a model which
529: does a good job of representing the documents of the class, including the
530: necessary entities and unencumbered by useless entities. The description of
531: the organization of the documents in the class can then be sufficiently
1.18 ! cvs 532: precise.</p>
! 533: </div>
1.1 cvs 534:
1.18 ! cvs 535: <div class="section">
1.1 cvs 536:
1.18 ! cvs 537: <h2><a name="sectb23">Logical structure and physical structure</a></h2>
! 538: <p>
! 539: Generic structures only describe the <em>logical</em> organization of
! 540: documents, not their <em>physical</em> presentation on a screen or on sheets
1.1 cvs 541: of paper. However, for a document to be displayed or printed, its graphic
1.18 ! cvs 542: presentation must be taken into account.</p>
! 543: <p>
1.1 cvs 544: An examination of current printed documents shows that the details of
545: presentation essentially serve to bring out their logical structure. Outside
546: of some particular domains, notably advertising, the presentation is rarely
547: independent of the logical organization of the text. Moreover, the art of
548: typography consists of enhancing the organization of the text being set,
549: without catching the eye of the reader with overly pronounced effects. Thus,
550: italic and boldface type are used to emphasize words or expressions which have
551: greater significance than the rest of the text: keywords, new ideas,
552: citations, book titles, etc. Other effects highlight the organization of the
553: text: vertical space, margin changes, page breaks, centering, eventually
554: combined with the changes in the shapes or weight of the characters. These
555: effects serve to indicate the transitions between paragraphs, sections, or
556: chapters: an object's level in the logical structure of the document is shown
1.18 ! cvs 557: by the markedness of the effects.</p>
! 558: <p>
1.1 cvs 559: Since the model permits the description of all of the logical structure of the
560: document, the presentation can be derived from the model without being
561: submerged in the document itself. It suffices to use the logical structure of
562: the document to make the desired changes in its presentation: changes in type
1.18 ! cvs 563: size, type style, spacing, margin, centering, etc.</p>
! 564: <p>
1.1 cvs 565: Just as one cannot define a unique generic logical structure for all document
566: classes, one cannot define universal presentation rules which can be applied
567: to all document classes. For certain types of documents the chapter titles
568: will be centered on the page and printed in large, bold type. For other
569: documents, the same chapter titles will be printed in small, italic type and
1.18 ! cvs 570: aligned on the left margin.</p>
! 571: <p>
1.1 cvs 572: Therefore, it is necessary to base the presentation specifications for
573: documents on their class. Such a specification can be very fine-grained,
574: because the presentation is expressed in terms of the entities defined in the
575: generic logical structure of the class. Thus, it is possible to specify a
576: different presentation for the chapter titles and the section titles, and
577: similarly to specify titles for the sections according to their level in the
578: section hierarchy. The set of rules which specify the presentation of all the
1.18 ! cvs 579: elements defined in a generic logical structure is called a <em>generic
! 580: presentation</em>.</p>
! 581: <p>
1.1 cvs 582: There are several advantages derived from having a presentation linked to the
583: generic structure and described by a generic presentation. Homogeneity is the
584: first. Since every document in a class corresponds to the same generic
585: logical structure, a homogenous presentation for different documents of the
586: same class can be assured by applying the same generic presentation to all
587: documents of the class. Homogeneity of presentation can also be found among
1.2 cvs 588: the entities of a single document: every section heading will be presented in
1.1 cvs 589: the same way, the first line of every paragraph of the same type will have the
1.18 ! cvs 590: same indentation, etc.</p>
! 591: <p>
1.1 cvs 592: Another advantage of this approach to presentation is that it facilitates
593: changes to the graphical aspect of documents. A change to the generic
594: presentation rules attached to each type of entity will alter the presentation
595: of the entire document, and will do so homogenously. In this case, the
596: internal homogeneity of the class is no longer assured, but the way to control
597: it is simple. It suffices to adopt a single generic presentation for the
1.18 ! cvs 598: entire class.</p>
! 599: <p>
1.1 cvs 600: If the presentation of the class does not have to be homogenous, then the
601: appearance of the document can be adapted to the way it will be used or to the
602: device used to render it. This quality is sufficient to allow the existence
1.18 ! cvs 603: of <a name="mulpres">many generic presentations</a> for the same document
1.1 cvs 604: class. By applying one or the other of these presentations to it, the document
605: can be seen under different graphical aspects. It must be emphasized that
606: this type of modification of the presentation is not a change to the document
607: itself (in its specific logical structure or its content), but only in its
1.18 ! cvs 608: appearance at the time of editing or printing.</p>
! 609: </div>
1.1 cvs 610:
1.18 ! cvs 611: <div class="section">
1.1 cvs 612:
1.18 ! cvs 613: <h2><a name="sectb24">Document structures and object structures</a></h2>
! 614: <p>
1.1 cvs 615: So far, we have only discussed the global structure of documents and have not
616: considered the contents found in that structure. We could limit ourselves to
617: purely textual contents by assuming that a title or a paragraph contains a
618: simple linear text. But this model would be too restrictive. In fact,
619: certain documents contain not only text, but also contain tables, diagrams,
620: photographs, mathematical formulas, and program fragments. The model must
1.18 ! cvs 621: permit the representation of such <em>objects</em>.</p>
! 622: <p>
1.1 cvs 623: Just as with the whole of the document, the model takes into account the
624: logical structure of objects of this type. Some are clearly structured,
625: others are less so. Logical structure can be recognized in mathematical
626: formulas, in tables, and in certain types of diagrams. On the other hand, it
627: is difficult to define the structure of a photograph or of some drawings. But
628: in any case, it does not seem possible to define one unique structure which
629: can represent every one of these types of objects. The approach taken in the
630: definition of meta-structure and document classes also applies to objects.
631: Object classes can be defined which put together objects of similar type,
1.18 ! cvs 632: constructed from the same generic logical structure.</p>
! 633: <p>
1.1 cvs 634: Thus, a mathematical class can be defined and have a generic logical structure
635: associated with it. But even if a single generic structure can represent a
636: sufficient variety of mathematical formulas, for other objects with less
637: rigorous structure, multiple classes must be defined. As for documents, using
638: multiple classes assures that the model can describe the full range of objects
639: to be presented. It also permits the system to support objects which were not
640: initially anticipated. Moreover, this comment applies equally to mathematics:
641: different classes of formulas can be described depending on the domain of
1.18 ! cvs 642: mathematics being described.</p>
! 643: <p>
1.1 cvs 644: Since objects have the same level of logical representation as documents, they
645: gain the same advantages. In particular, it is possible to define the
646: presentation separately from the objects themselves and attach it to the
647: class. Thus, as for documents, objects of the same type have a uniform
648: presentation and the presentation of every object in a given class can be
649: changed simply by changing the generic presentation of the class. Another
650: advantage of using this document model is that the system does not bother the
651: user with the details of presentation, but rather allows the user to
1.18 ! cvs 652: concentrate on the logical aspect of the document and the objects.</p>
! 653: <p>
1.1 cvs 654: It is clear that the documents in a class do not necessarily use the same
655: classes of objects: one technical report will contain tables while another
656: report will have no tables but will use mathematical formulas. The usable
1.2 cvs 657: object classes are not always mentioned in a limiting way in the generic
658: logical structure of documents. Rather, they can be chosen freely from a
1.18 ! cvs 659: large set, independent of the document class.</p>
! 660: <p>
1.1 cvs 661: Thus, the object classes will be made commonplace and usable in every
662: document. The notion of ``object'' can be enlarged to include not only
663: non-textual elements, but also certain types of textual elements which can
664: appear in practically every document, whatever their class. Among these
1.2 cvs 665: textual elements, one can mention enumerations, descriptions, examples,
1.18 ! cvs 666: quotations, even paragraphs.</p>
! 667: <p>
1.1 cvs 668: Thus, the document model is not a single, general model describing every type
669: of document in one place. Rather, it is a meta-model which can be used to
670: describe many different models each of which represents either a class of
671: similar documents or a class of similar objects which every document can
1.18 ! cvs 672: include.</p>
! 673: </div>
! 674: <hr>
! 675: </div>
1.1 cvs 676:
1.18 ! cvs 677: <div class="chapter">
1.1 cvs 678:
1.18 ! cvs 679: <h1><a name="sect3">The S language</a></h1>
1.1 cvs 680:
1.18 ! cvs 681: <div class="section">
1.1 cvs 682:
1.18 ! cvs 683: <h2><a name="sectb31">Document meta-structure</a></h2>
! 684: <p>
1.1 cvs 685: Since the concept of meta-structure is well suited to the task of describing
686: documents at a high level of abstraction, this meta-structure must be
687: precisely defined. Toward that end this section first presents the basic
688: elements from which documents and structured objects are composed and then
689: specifies the ways in which these basic elements are assembled into structures
1.18 ! cvs 690: representing complete documents and objects.</p>
1.1 cvs 691:
1.18 ! cvs 692: <div class="subsection">
1.1 cvs 693:
1.18 ! cvs 694: <h3><a name="sectc311">The basic types</a></h3>
! 695: <p>
1.1 cvs 696: At the lowest level of a document's structure, the first atom considered is
697: the character. However, since characters are seldom isolated, usually
698: appearing as part of a linear sequence, and in order to reduce the complexity
1.18 ! cvs 699: of the document structure, <em>character strings</em> are used as atoms and
1.1 cvs 700: consecutive characters belonging to the same structural element are grouped in
1.18 ! cvs 701: the same character string.</p>
! 702: <p>
1.1 cvs 703: If the structure of a document is not refined to go down to the level of
704: words or phrases, the contents of a simple paragraph can be considered to be a
705: single character string. On the other hand, the title of a chapter, the title
706: of the first section of that chapter, and the text of the first paragraph of
707: that section constitute three different character strings, because they belong
1.18 ! cvs 708: to distinct structural elements.</p>
! 709: <p>
1.1 cvs 710: If, instead, a very fine-grained representation for the structure of a
711: document is sought, character strings could be defined to contain only a
712: single word, or even just a single character. This is the case, for example,
713: in programs, for which one wants to retain a structure very close to the
1.2 cvs 714: syntax of the programming language. In this case, an assignment statement
1.1 cvs 715: initializing a simple variable to zero would be composed of two structural
716: elements, the identifier of the variable (a short character string) and the
1.18 ! cvs 717: assigned value (a string of a single character, `0').</p>
! 718: <p>
1.1 cvs 719: The character string is not the only atom necessary for representing those
720: documents that interest us. It suffices for purely textual documents, but as
721: soon as the non-textual objects which we have considered arise, there must be
722: other atoms; the number of objects which are to be represented determines the
1.18 ! cvs 723: number of types of atoms that are necessary.</p>
! 724: <p>
! 725: Primitive <em>graphical elements</em> are used for tables and figures of
1.1 cvs 726: different types. These elements are simple geometric shapes like horizontal
727: or vertical lines, which are sufficient for tables, or even oblique lines,
1.2 cvs 728: arrows, rectangles, circles, polygons, and curves for use in figures. From
729: these elements and character strings, graphical objects and tables can be
1.18 ! cvs 730: constructed.</p>
! 731: <p>
1.1 cvs 732: Photographs, though having very little structure, must still appear in
1.18 ! cvs 733: documents. They are supported by <em>picture</em> elements, which are
! 734: represented as matrices of pixels.</p>
! 735: <p>
1.1 cvs 736: Finally, mathematical notations require certain elements which are
1.18 ! cvs 737: simultaneously characters and graphical elements, the <em>symbols</em>. By way
1.2 cvs 738: of example, radicals, integration signs, or even large parentheses are
1.1 cvs 739: examples of this type of atom. The size of each of these symbols is
740: determined by its environment, that is to say, by the expression to which it
1.18 ! cvs 741: is attached.</p>
! 742: <p>
1.1 cvs 743: To summarize, the primitive elements which are used in the construction of
1.18 ! cvs 744: documents and structured objects are:</p>
! 745: <ul>
! 746: <li>
! 747: character strings,
! 748: <li>
! 749: graphical elements,
! 750: <li>
! 751: pictures,
! 752: <li>
! 753: and mathematical symbols.
! 754: </ul>
! 755: </div>
1.1 cvs 756:
1.18 ! cvs 757: <div class="subsection">
1.1 cvs 758:
1.18 ! cvs 759: <h3><a name="sectc312">Constructed elements</a></h3>
! 760: <p>
1.1 cvs 761: A document is evidently formed from primitive elements. But the model of Thot
762: also proposes higher level elements. Thus, in a document composed of several
763: chapters, each chapter is an element, and in the chapters each section is also
1.18 ! cvs 764: an element, and so on. A document is thus an organized set of elements.</p>
! 765: <p>
1.1 cvs 766: In a document there are different sorts of elements. Each element has a
1.18 ! cvs 767: <em>type</em> which indicates the role of the element within the document as a
1.1 cvs 768: whole. Thus, we have, for example, the chapter and section types. The
769: document is made up of typed elements: elements of the type chapter and
770: elements of the type section, among others, but also character string elements
771: and graphical elements: the primitive elements are typed elements just as
772: well. At the other extreme, the document itself is also considered to be a
1.18 ! cvs 773: typed element.</p>
! 774: <p>
1.1 cvs 775: The important difference between the primitive elements and the other elements
776: of the document is that the primitive elements are atoms (they cannot be
1.18 ! cvs 777: decomposed), whereas the others, called <em>constructed elements</em>, are
1.1 cvs 778: composed of other elements, which can either be primitive elements or
779: constructed elements. A constructed element of type chapter (or more simply,
780: ``a chapter'') is composed of sections, which are also constructed elements. A
781: paragraph, a constructed element, can be made up of character strings, which
1.18 ! cvs 782: are primitive elements, and of equations, which are constructed elements.</p>
! 783: <p>
1.1 cvs 784: A document is also a constructed element. This is an important point. In
785: particular, it allows a document to be treated as part of another document,
786: and conversely, permits a part of a document to be treated as a complete
787: document. Thus, an article presented in a journal is treated by its author as
788: a document in itself, while the editor of the journal considers it to be part
789: of an issue. A table or a figure appearing in a document can be extracted and
790: treated as a complete document, for example to prepare transparencies for a
1.18 ! cvs 791: conference.</p>
! 792: <p>
1.1 cvs 793: These thoughts about types and constructed elements apply just as well to
794: objects as they do to documents. A table is a constructed element made up of
795: other constructed elements, rows and columns. A row is formed of cells, which
796: are also constructed elements which contain primitive elements (character
1.18 ! cvs 797: strings) and/or constructed elements like equations.</p>
! 798: </div>
1.1 cvs 799:
1.18 ! cvs 800: <div class="subsection">
1.1 cvs 801:
1.18 ! cvs 802: <h3><a name="sectc313">Logical structure constructors</a></h3>
! 803: <p>
1.1 cvs 804: Having defined the primitive elements and the constructed elements, it is now
805: time to define the types of organization which allow the building of
1.18 ! cvs 806: structures. For this, we rely on the notion of the <em>constructor</em>. A
1.1 cvs 807: constructor defines a way of assembling certain elements in a structure. It
808: resides at the level of the meta-structure: it does not describe the existing
809: relations in a given structure, but rather defines how elements are assembled
1.18 ! cvs 810: to build a structure that conforms to a model.</p>
! 811: <p>
1.1 cvs 812: In defining the overall organization of documents, the first two constructors
1.18 ! cvs 813: considered are the aggregate and the list.</p>
1.1 cvs 814:
1.18 ! cvs 815: <div class="subsubsection">
1.1 cvs 816:
1.18 ! cvs 817: <h4><a name="sectd3131">Aggregate and List</a></h4>
! 818: <p>
! 819: The <em>aggregate</em> constructor is used to define constructed element types
1.1 cvs 820: which are collections of a given number of other elements. These collections
821: may or may not be ordered. The elements may be either constructed or
822: primitive and are specified by their type. A report (that is, a constructed
823: element of the report type) has an aggregate structure. It is formed from a
824: title, an author's name, an introduction, a body, and a conclusion, making it
825: a collection of five element types. This type of constructor is found in
1.18 ! cvs 826: practically every document, and generally at several levels in a document.</p>
! 827: <p>
! 828: The <em>list</em> constructor is used to define constructed elements which are
1.1 cvs 829: ordered sequences of elements (constructed or primitive) having the same type.
830: The minimum and maximum numbers of elements for the sequence can be specified
831: in the list constructor or the number of elements can be left unconstrained.
832: The body of a report is a list of chapters and is typically required to
833: contain a minimum of two chapters (is a chapter useful if it is the only one
834: in the report?) The chapter itself can contain a list of sections, each
1.2 cvs 835: section containing a list of paragraphs. In the same way as the aggregate,
1.18 ! cvs 836: the list is a very frequently used constructor in every type of document.
1.2 cvs 837: However, these two constructors are not sufficient to describe every document
1.18 ! cvs 838: structure; thus other constructors supplement them.</p>
! 839: </div>
1.1 cvs 840:
1.18 ! cvs 841: <div class="subsubsection">
1.1 cvs 842:
1.18 ! cvs 843: <h4><a name="sectd3132">Choice, Schema, and Unit</a></h4>
! 844: <p>
! 845: The <em>choice</em> constructor is used to define the structure of an element
1.1 cvs 846: type for which one alternative is chosen from several possibilities. Thus, a
847: paragraph can be either a simple text paragraph, or an enumeration, or a
1.18 ! cvs 848: citation.</p>
! 849: <p>
1.1 cvs 850: The choice constructor indicates the complete list of possible options, which
851: can be too restrictive in certain cases, the paragraph being one such case.
1.18 ! cvs 852: Two constructors, <em>unit</em> and <em>schema</em>, address this
1.1 cvs 853: inconvenience. They allow more freedom in the choice of an element type. If
854: a paragraph is defined by a schema constructor, it is possible to put in the
855: place of a paragraph a table, an equation, a drawing or any other object
856: defined by another generic logical structure. It is also possible to define a
857: paragraph as a sequence of units, which could be character strings, symbols,
1.2 cvs 858: or pictures. The choice constructor alone defines a generic logical structure
1.1 cvs 859: that is relatively constrained; in contrast, using units and schemas, a very
1.18 ! cvs 860: open structure can be defined.</p>
! 861: <p>
! 862: The <em>schema</em> constructor represents an object defined by a generic
! 863: logical structure chosen freely from among those available.</p>
! 864: <p>
! 865: The <em>unit</em> constructor represents an element whose type can be either a
1.1 cvs 866: primitive type or an element type defined as a unit in the generic logical
867: structure of the document, or in another generic logical structure used in the
868: document. Such an element may be used in document objects constructed
1.18 ! cvs 869: according to other generic structures.</p>
! 870: <p>
1.1 cvs 871: Thus, for example, if a cross-reference to a footnote is defined in the
872: generic logical structure ``Article'' as a unit, a table (an object defined by
873: another generic structure) can contain cross-references to footnotes, when
874: they appear in an article. In another type of document, a table defined by
875: the same generic structure can contain other types of elements, depending on
876: the type of document into which the table is inserted. All that is needed is
877: to declare, in the generic structure for tables, that the contents of cells
878: are units. In this way, the generic structure of objects is divided up
879: between different types of documents which are able to adapt themselves to the
1.18 ! cvs 880: environment into which they are inserted.</p>
! 881: </div>
1.1 cvs 882:
1.18 ! cvs 883: <div class="subsubsection">
1.1 cvs 884:
1.18 ! cvs 885: <h4><a name="sectd3133">Reference and Inclusion</a></h4>
! 886: <p>
! 887: The <em>reference</em> is used to define document elements that are
! 888: cross-references to other elements, such as a section, a chapter, a
! 889: bibliographic citation, or a figure. The reference is bi-directional. It can
! 890: be used to access both the element being cross-referenced and each of the
! 891: elements which make use of the cross-reference.</p>
! 892: <p>
! 893: References can be either <em>internal</em> or <em>external</em>. That is,
1.1 cvs 894: they can designate elements which appear in the same document or in another
1.18 ! cvs 895: document.</p>
! 896: <p>
! 897: The <em><a name="inclusion">inclusion</a></em> constructor is a special type
1.1 cvs 898: of reference. Like the reference, it is an internal or external bidirectional
899: link, but it is not a cross-reference. This link represents the ``live''
900: inclusion of the designated element; it accesses the most recent version of
901: that element and not a ``dead'' copy, fixed in the state in which it was found
902: at the moment the copy was made. As soon as an element is modified, all of
903: its inclusions are automatically brought up to date. It must be noted that,
1.18 ! cvs 904: in addition to inclusion, Thot permits the creation of ``dead'' copies.</p>
! 905: <p>
1.1 cvs 906: There are three types of inclusions: inclusions with full expansion,
907: inclusions with partial expansion, and inclusions without expansion. During
908: editing, inclusions without expansion are represented on the screen by the
909: name of the included document, in a special color, while inclusions with
910: expansion (full or partial) are represented by a copy (full or partial) of the
911: included element (also in a special color). The on-screen representation of a
1.18 ! cvs 912: partial inclusion is a <a href="#sectc3213">``skeleton''</a> image of the
! 913: included document.</p>
! 914: <p>
1.1 cvs 915: Inclusion with complete expansion can be used to include parts of the same
916: document or of other documents. Thus, it can be either an internal or an
917: external link. It can be used to include certain bibliographic entries of a
918: scientific article in another article, or to copy part of a mathematical
919: formula into another formula of the same document, thus assuring that both
1.18 ! cvs 920: copies will remain synchronized.</p>
! 921: <p>
1.1 cvs 922: Inclusion without expansion or with partial expansion is used to include
923: complete documents. It is always an external link. It is used primarily to
924: divide very large documents into sub-documents that are easier to manipulate,
925: especially when there are many authors. So, a book can include some chapters,
926: where each chapter is a different document which can be edited separately.
927: When viewing the book on the screen, it might be desirable to see only the
928: titles of the chapters and sections. This can be achieved using inclusion
1.18 ! cvs 929: with partial expansion.</p>
! 930: <p>
1.1 cvs 931: During printing, inclusions without expansion or with partial expansion can be
932: represented either as they were shown on the screen or by a complete (and
1.18 ! cvs 933: up-to-date) copy of the included element or document.</p>
! 934: <p>
1.1 cvs 935: The inclusion constructor, whatever its type, respects the generic structure:
936: only those elements authorized by the generic structure can be included at a
1.18 ! cvs 937: given position in a document.</p>
! 938: </div>
1.1 cvs 939:
1.18 ! cvs 940: <div class="subsubsection">
1.1 cvs 941:
1.18 ! cvs 942: <h4><a name="sectd3134">Mark pairs</a></h4>
! 943: <p>
1.1 cvs 944: It is often useful to delimit certain parts of a document independently from
945: the logical structure. For example, one might wish to attach some information
1.18 ! cvs 946: (in the form of an <a href="#sectc315">attribute</a>) or a particular
! 947: treatment to a group of words or a set of consecutive paragraphs. <em>Mark
! 948: pairs</em> are used to do this.</p>
! 949: <p>
1.1 cvs 950: Mark pairs are elements which are always paired and are terminals in the
951: logical structure of the document. Their position in the structure of the
952: document is defined in the generic structure. It is important to note that
1.18 ! cvs 953: when the terminals of a mark pair are <em>extensions</em> (see the next
! 954: section), they can be used quite freely.</p>
! 955: </div>
1.1 cvs 956:
1.18 ! cvs 957: <div class="subsubsection">
1.1 cvs 958:
1.18 ! cvs 959: <h4><a name="sectd3135">Restrictions and Extensions</a></h4>
! 960: <p>
1.1 cvs 961: The primitive types and the constructors presented so far permit the
962: definition of the logical structure of documents and objects in a rigorous
963: way. But this definition can be very cumbersome in certain cases, notably
964: when trying to constrain or extend the authorized element types in a
1.18 ! cvs 965: particular context. <em>Restrictions</em> and <em>extensions</em> are used to
! 966: cope with these cases.</p>
! 967: <p>
! 968: A restriction associates with a particular element type <em>A</em>, a list of
! 969: those element types which elements of type <em>A</em> may not contain, even if
! 970: the definition of type <em>A</em> and those of its components authorize them
1.1 cvs 971: otherwise. This simplifies the writing of generic logical structures and
972: allows limitations to be placed, when necessary, on the choices offered by the
1.18 ! cvs 973: schema and unit constructors.</p>
! 974: <p>
1.1 cvs 975: Extensions are the inverse of restrictions. They identify a list of element
1.18 ! cvs 976: types whose presence <em>is</em> permitted, even if its definition and those
! 977: of its components do not authorize them otherwise.</p>
! 978: </div>
! 979:
! 980: <div class="subsubsection">
! 981:
! 982: <h4><a name="sectd3136">Summary</a></h4>
! 983: <p>
! 984: Thus, four constructors are used to construct a document:</p>
! 985: <ul>
! 986: <li>
! 987: the aggregate constructor (ordered or not),
! 988: <li>
! 989: the list constructor,
! 990: <li>
! 991: the choice constructor and its extensions, the unit and schema constructors,
! 992: <li>
! 993: the reference constructor and its variant, the inclusion.
! 994: </ul>
! 995: <p>
1.1 cvs 996: These constructors are also sufficient for objects. Thus, these constructors
997: provide a homogenous meta-model which can describe both the organization of
998: the document as a whole and that of the various types of objects which it
999: contains. After presenting the description language for generic structures,
1000: we will present several examples which illustrate the appropriateness of the
1.18 ! cvs 1001: model.</p>
! 1002: <p>
1.1 cvs 1003: The first three constructors (aggregate, list and choice) lead to tree-like
1004: structures for documents and objects, the objects being simply the subtrees of
1005: the tree of a document (or even of other objects' subtrees). The reference
1006: constructor introduces other, non-hierarchical, relations which augment those
1007: of the tree: when a paragraph makes reference to a chapter or a section, that
1008: relation leaves the purely tree-like structure. Moreover, external reference
1009: and inclusion constructors permit the establishment of links between different
1.18 ! cvs 1010: documents, thus creating a hypertext structure.</p>
! 1011: </div>
! 1012: </div>
1.1 cvs 1013:
1.18 ! cvs 1014: <div class="subsection">
1.1 cvs 1015:
1.18 ! cvs 1016: <h3><a name="sectc314">Associated Elements</a></h3>
! 1017: <p>
1.1 cvs 1018: Thanks to the list, aggregate and choice constructors, the organization of the
1019: document is specified rigorously, using constructed and primitive elements.
1020: But a document is made up of more than just its elements; it clearly also
1021: contains links between them. There exist elements whose position in the
1022: document's structure is not determinable. This is notably the case for
1023: figures and notes. A figure can be designated at many points in the same
1024: document and its place in the physical document can vary over the life of the
1025: document without any effect on the meaning or clarity of the document. At one
1026: time, it can be placed at the end of the document along with all other
1027: figures. At another time, it can appear at the top of the page which follows
1028: the first mention of the figure. The figures can be dispersed throughout the
1029: document or can be grouped together. The situation is similar for notes,
1030: which can be printed at the bottom of the page on which they are mentioned or
1031: assembled together at the end of the chapter or even the end of the work. Of
1032: course, this brings up questions of the physical position of elements in
1033: documents that are broken into pages, but this reflects the structural
1034: instability of these elements. They cannot be treated the same way as
1035: elements like paragraphs or sections, whose position in the structure is
1.18 ! cvs 1036: directly linked to the semantics of the document.</p>
! 1037: <p>
1.1 cvs 1038: Those elements whose position in the structure of the document is not fixed,
1039: even though they are definitely part of the document, are called
1.18 ! cvs 1040: <em>associated elements</em>. Associated elements are themselves structures,
1.1 cvs 1041: which is to say that their content can be organized logically by the
1.18 ! cvs 1042: constructors from primitive and constructed elements.</p>
! 1043: <p>
1.1 cvs 1044: It can happen that the associated elements are totally disconnected from the
1045: structure of the document, as in a commentary or appraisal of the entire work.
1046: But more often, the associated elements are linked to the content of the
1047: document by references. This is generally the case for notes and figures,
1.18 ! cvs 1048: among others.</p>
! 1049: <p>
1.1 cvs 1050: Thus, associated elements introduce a new use for the reference constructor.
1051: It not only serves to create links between elements of the principal structure
1052: of the document, but also serves to link the associated elements to the
1.18 ! cvs 1053: primary structure.</p>
! 1054: </div>
1.1 cvs 1055:
1.18 ! cvs 1056: <div class="subsection">
1.1 cvs 1057:
1.18 ! cvs 1058: <h3><a name="sectc315">Attributes</a></h3>
! 1059: <p>
1.1 cvs 1060: There remain logical aspects of documents that are not entirely described by
1061: the structure. Certain types of semantic information, which are not stated
1062: explicitly in the text, must also be taken into account. In particular, such
1063: information is shown by typographic effects which do not correspond to a
1064: change between structural elements. In fact, certain titles are set in bold
1065: or italic or are printed in a different typeface from the rest of the text in
1066: order to mark them as structurally distinct. But these same effects
1067: frequently appear in the middle of continuous text (e.g. in the interior of a
1068: paragraph). In this case, there is no change between structural elements; the
1069: effect serves to highlight a word, expression, or phrase. The notion of an
1.18 ! cvs 1070: <em>attribute</em> is used to express this type of information.</p>
! 1071: <p>
1.1 cvs 1072: An attribute is a piece of information attached to a structural element which
1073: augments the type of the element and clarifies its function in the document.
1074: Keywords, foreign language words, and titles of other works can all be
1075: represented by character strings with attached attributes. Attributes may
1076: also be attached to constructed elements. Thus, an attribute indicating the
1077: language can be attached to a single word or to a large part of a
1.18 ! cvs 1078: document.</p>
! 1079: <p>
1.1 cvs 1080: In fact, an attribute can be any piece of information which is linked to a
1081: part of a document and which can be used by agents which work on the document.
1082: For example, the language in which the document is written determines the set
1083: of characters used by an editor or formatter. It also determines the
1084: algorithm or hyphenation dictionary to be used. The attribute ``keyword''
1085: facilitates the work of an information retrieval system. The attribute
1086: ``index word'' allows a formatter to automatically construct an index at the
1.18 ! cvs 1087: end of the document.</p>
! 1088: <p>
1.1 cvs 1089: As with the types of constructed elements, the attributes and the values they
1090: can take are defined separately in each generic logical structure, not in the
1091: meta-model, according to the needs of the document class or the nature of the
1.18 ! cvs 1092: object.</p>
! 1093: <p>
1.1 cvs 1094: Many types of attributes are offered: numeric, textual, references, and
1.18 ! cvs 1095: enumerations:</p>
! 1096: <ul>
! 1097: <li>
! 1098: <em>Numeric attributes</em> can take integer values (negative, positive, or
! 1099: null).
! 1100: <li>
! 1101: <em>Textual attributes</em> have as their values character strings.
! 1102: <li>
! 1103: <em>Reference attributes</em> designate an element of the logical structure.
! 1104: <li>
! 1105: <em>Enumeration attributes</em> can take one value from a limited list of
1.1 cvs 1106: possible values, each value being a name.
1.18 ! cvs 1107: </ul>
! 1108: <p>
! 1109: In a generic structure, there is a distinction between <em>global
! 1110: attributes</em> and <em>local attributes</em>. A global attribute can be
1.1 cvs 1111: applied to every element type defined in the generic structure where it is
1112: specified. In contrast, a local attribute can only be applied to certain
1113: types of elements, even only a single type. The ``language'' attribute
1114: presented above is an example of a global attribute. An example of a local
1115: attribute is the rank of an author (principal author of the document or
1116: secondary author): this attribute can only be applied sensibly to an element
1.18 ! cvs 1117: of the ``author'' type.</p>
! 1118: <p>
1.1 cvs 1119: Attributes can be assigned to the elements which make up the document in many
1120: different ways. The author can freely and dynamically place them on any part
1.18 ! cvs 1121: of the document in order to attach supplementary information of his/her
! 1122: choice. However, attributes may only be assigned in accordance with the rules
! 1123: of the generic structure; in particular, local attributes can only be assigned
! 1124: to those element types for which they are defined.</p>
! 1125: <p>
1.1 cvs 1126: In the generic structure, certain local attributes can be made mandatory for
1.2 cvs 1127: certain element types. In this case, Thot automatically associates the
1128: attribute with the elements of this type and it requires the user to provide a
1.18 ! cvs 1129: value for this attribute.</p>
! 1130: <p>
1.1 cvs 1131: Attributes can also be automatically assigned, with a given value, by every
1132: application processing the document in order to systematically add a piece of
1133: information to certain predefined elements of the document. By way of
1134: example, in a report containing a French abstract and an English abstract,
1135: each of the two abstracts is defined as a sequence of paragraphs. The first
1136: abstract has a value of ``French'' for the ``language'' attribute while the
1.18 ! cvs 1137: second abstract's ``language'' attribute has a value of ``English''.</p>
! 1138: <p>
1.1 cvs 1139: In the case of mark pairs, attributes are logically associated with the pair
1.18 ! cvs 1140: as a whole, but are actually attached to the first mark.</p>
! 1141: </div>
1.1 cvs 1142:
1.18 ! cvs 1143: <div class="subsection">
1.1 cvs 1144:
1.18 ! cvs 1145: <h3><a name="sectc316">Discussion of the model</a></h3>
! 1146: <p>
1.1 cvs 1147: The notions of attribute, constructor, structured element, and associated
1148: element are used in the definition of generic logical structures of documents
1149: and objects. The problem is to assemble them to form generic structures. In
1150: fact, many types of elements and attributes can be found in a variety of
1151: generic structures. Rather than redefine them for each structure in which
1152: they appear, it is best to share them between structures. The object classes
1153: already fill this sharing function. If a mathematical class is defined, its
1154: formulas can be used in many different document classes, without redefining
1155: the structure of each class. This problem arises not only for the objects
1156: considered here; it also arises for the commonplace textual elements found in
1157: many document classes. This is the reason why the notion of object is so
1158: broad and why paragraphs and enumerations are also considered to be objects.
1159: These object classes not only permit the sharing of the structures of
1.18 ! cvs 1160: elements, but also of the attributes defined in the generic structures.</p>
! 1161: <p>
1.1 cvs 1162: Structure, such as that presented here, can appear very rigid, and it is
1163: possible to imagine that a document editing system based on this model could
1164: prove very constraining to the user. This is, in fact, a common criticism of
1165: syntax-directed editors. This defect can be avoided with Thot, primarily for
1.18 ! cvs 1166: three reasons:</p>
! 1167: <ul>
! 1168: <li>
! 1169: the generic structures are not fixed in the model itself,
! 1170: <li>
! 1171: the model takes the dynamics of documents into account,
! 1172: <li>
! 1173: the constructors offer great flexibility.
! 1174: </ul>
! 1175: <p>
1.1 cvs 1176: When the generic structure of a document is not predefined, but rather is
1177: constructed specifically for each document class, it can be carefully adapted
1178: to the current needs. In cases where the generic structure is inadequate for
1179: a particular document of the class, it is always possible either to create a
1180: new class with a generic structure well suited to the new case or to extend
1181: the generic structure of the existing class to take into account the specifics
1182: of the document which poses the problem. These two solutions can also be
1.18 ! cvs 1183: applied to objects whose structures prove to be poorly designed.</p>
! 1184: <p>
1.1 cvs 1185: The model is sufficiently flexible to take into account all the phases of the
1186: life of the document. When a generic structure specifies that a report must
1187: contain a title, an abstract, an introduction, at least two chapters, and a
1.18 ! cvs 1188: conclusion, this means only that a report, <em>upon completion</em>, will have
1.1 cvs 1189: to contain all of these elements. When the author begins writing, none of
1.2 cvs 1190: these elements is present. Thot uses this model. Therefore, it tolerates
1191: documents which do not conform strictly to the generic structure of their
1192: class; it also considers the generic logical structure to be a way of helping
1.18 ! cvs 1193: the user in the construction of a complex document.</p>
! 1194: <p>
1.1 cvs 1195: In contrast, other applications may reject a document which does not conform
1196: strictly to its generic structure. This is, for example, what is done by
1197: compilers which refuse to generate code for a program which is not
1198: syntactically correct. This might also occur when using a document
1.18 ! cvs 1199: application for a report which does not have an abstract or title.</p>
! 1200: <p>
1.1 cvs 1201: The constructors of the document model bring a great flexibility to the
1202: generic structures. A choice constructor (and even more, a unit or schema
1203: constructor) can represent several, very different elements. The list
1204: constructor permits the addition of more elements of the same type. Used
1205: together, these two constructors permit any series of elements of different
1206: types. Of course, this flexibility can be reduced wherever necessary since a
1207: generic structure can limit the choices or the number of elements in a
1.18 ! cvs 1208: list.</p>
! 1209: <p>
1.1 cvs 1210: Another difficulty linked to the use of structure in the document model
1211: resides in the choice of the level of the structure. The structure of a
1212: discussion could be extracted from the text itself via linguistic analysis.
1213: Some studies are exploring this approach, but the model of Thot excludes this
1214: type of structure. It only takes into account the logical structure provided
1.18 ! cvs 1215: explicitly by the author.</p>
! 1216: <p>
1.1 cvs 1217: However, the level of structure of the model is not imposed. Each generic
1218: structure defines its own level of structure, adapted to the document class or
1219: object and to the ways in which it will be processed. If it will only be
1220: edited and printed, a relatively simple structure suffices. If more
1221: specialized processing will be applied to it, the structure must represent the
1222: element types on which this processing must act. By way of example, a simple
1223: structure is sufficient for printing formulas, but a more complex structure is
1224: required to perform symbolic or numeric calculations on the mathematical
1.18 ! cvs 1225: expressions. The document model of Thot allows both types of structure.</p>
! 1226: </div>
! 1227: </div>
1.1 cvs 1228:
1.18 ! cvs 1229: <div class="section">
1.1 cvs 1230:
1.18 ! cvs 1231: <h2><a name="sectb32">The definition language for generic structures</a></h2>
! 1232: <p>
1.1 cvs 1233: Generic structures, which form the basis of the document model of Thot, are
1234: specified using a special language. This definition language, called S, is
1.18 ! cvs 1235: described in this section.</p>
! 1236: <p>
1.1 cvs 1237: Each generic structure, which defines a class of documents or objects, is
1.2 cvs 1238: specified by a file, written in the S language, which is called a
1.18 ! cvs 1239: <em>structure schema</em>. Structure schemas are compiled into tables, called
! 1240: structure tables, which are used by Thot and which determine its behavior.</p>
1.1 cvs 1241:
1.18 ! cvs 1242: <div class="subsection">
1.1 cvs 1243:
1.18 ! cvs 1244: <h3><a name="sectc321">Writing Conventions</a></h3>
! 1245: <p>
1.1 cvs 1246: The grammar of S, like those of the languages P and T presented later, is
1247: described using the meta-language M, derived from the Backus-Naur Form
1.18 ! cvs 1248: (BNF).</p>
! 1249: <p>
1.1 cvs 1250: In this meta-language each rule of the grammar is composed of a grammar symbol
1251: followed by an equals sign (`=') and the right part of the rule. The equals
1252: sign plays the same role as the traditional `::=' of BNF: it indicates that
1.18 ! cvs 1253: the right part defines the symbol of the left part. In the right part,</p>
! 1254: <dl>
! 1255: <dt>concatenation</dt>
! 1256: <dd>
! 1257: is shown by the juxtaposition of symbols;
! 1258: </dd>
! 1259: <dt>character strings</dt>
! 1260: <dd>
! 1261: between apostrophes ' represent terminal symbols, that is, keywords in the
1.2 cvs 1262: language defined. Keywords are written here in upper-case letters, but can be
1263: written in any combination of upper and lower-case letters. For example, the
1.18 ! cvs 1264: keyword <tt>DEFPRES</tt> of S can also be written as <tt>defpres</tt> or
! 1265: <tt>DefPres</tt>.
! 1266: </dd>
! 1267: <dt>material between brackets</dt>
! 1268: <dd>
! 1269: (`[' and `]') is optional;
! 1270: </dd>
! 1271: <dt>material between angle brackets</dt>
! 1272: <dd>
! 1273: (`<' and `>') can be repeated many times or omitted;
! 1274: </dd>
! 1275: <dt>the slash</dt>
! 1276: <dd>
! 1277: (`/') indicates an alternative, a choice between the options separated by the
! 1278: slash character;
! 1279: </dd>
! 1280: <dt>the period</dt>
! 1281: <dd>
! 1282: marks the end of a rule;
! 1283: </dd>
! 1284: <dt>text between braces</dt>
! 1285: <dd>
! 1286: (`{' and `}') is simply a comment.
! 1287: </dd>
! 1288: </dl>
! 1289: <p>
1.1 cvs 1290: The M meta-language also uses the concepts of identifiers, strings, and
1.18 ! cvs 1291: integers:</p>
! 1292: <dl>
! 1293: <dt><tt>NAME</tt></dt>
! 1294: <dd>
! 1295: represents an identifier, a sequence of letters (upper or lower-case), digits,
! 1296: and underline characters (`_'), beginning with a letter. Also considered a
! 1297: letter is the sequence of characters `<tt>\nnn</tt>' where the letter
! 1298: <tt>n</tt> represents the ISO Latin-1 code of the letter in octal. It is thus
! 1299: possible to use accented letters in identifiers. The maximum length of
! 1300: identifiers is fixed by the compiler. It is normally 31 characters.
! 1301: <p>
1.1 cvs 1302: Unlike keywords, upper and lower-case letters are distinct in identifiers.
1.18 ! cvs 1303: Thus, <tt>Title</tt>, <tt>TITLE</tt>, and <tt>title</tt> are considered
! 1304: different identifiers.</p>
! 1305: </dd>
! 1306: <dt><tt>STRING</tt></dt>
! 1307: <dd>
! 1308: represents a string. This is a string of characters delimited by apostrophes.
! 1309: If an apostrophe must appear in a string, it is doubled. As with identifiers,
! 1310: strings can contain characters represented by their octal code (after a
! 1311: backslash). As with apostrophes, if a backslash must appear in a string, it
! 1312: is doubled.
! 1313: </dd>
! 1314: <dt><tt>NUMBER</tt></dt>
! 1315: <dd>
! 1316: represents a positive integer or zero (without a sign), or said another way, a
! 1317: sequence of decimal digits.
! 1318: </dd>
! 1319: </dl>
! 1320: <p>
! 1321: The M language can be used to define itself as follows:</p>
! 1322: <pre>{ Any text between braces is a comment. }
1.1 cvs 1323: Grammar = Rule < Rule > 'END' .
1324: { The < and > signs indicate zero }
1325: { or more repetitions. }
1326: { END marks the end of the grammar. }
1327: Rule = Ident '=' RightPart '.' .
1328: { The period indicates the end of a rule }
1329: RightPart = RtTerminal / RtIntermed .
1330: { The slash indicates a choice }
1331: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
1332: { Right part of a terminal rule }
1333: RtIntermed = Possibility < '/' Possibility > .
1334: { Right part of an intermediate rule }
1335: Possibility = ElemOpt < ElemOpt > .
1336: ElemOpt = Element / '[' Element < Element > ']' /
1337: '<' Element < Element > '>' .
1338: { Brackets delimit optional parts }
1339: Element = Ident / KeyWord .
1340: Ident = NAME .
1341: { Identifier, sequence of characters }
1342: KeyWord = STRING .
1343: { Character string delimited by apostrophes }
1.18 ! cvs 1344: END</pre>
! 1345: </div>
1.1 cvs 1346:
1.18 ! cvs 1347: <div class="subsection">
1.1 cvs 1348:
1.18 ! cvs 1349: <h3><a name="sectc322">Extension schemas</a></h3>
! 1350: <p>
1.1 cvs 1351: A structure schema defines the generic logical structure of a class of
1352: documents or objects, independent of the operations which can be performed on
1353: the documents. However, certain applications may require particular
1354: information to be represented by the structure for the documents that they
1355: operate on. Thus a document version manager will need to indicate in the
1356: document the parts which belong to one version or another. An indexing system
1357: will add highly-structured index tables as well as the links between these
1.18 ! cvs 1358: tables and the rest of the document.</p>
! 1359: <p>
1.2 cvs 1360: Thus, many applications need to extend the generic structure of the documents
1361: on which they operate to introduce new attributes, associated elements or
1.1 cvs 1362: element types. These additions are specific to each application and must be
1363: able to be applied to any generic structure: users will want to manage
1364: versions or construct indices for many types of documents. Extension schemas
1365: fulfill this role: they define attributes, elements, associated elements,
1366: units, etc., but they can only be used jointly with a structure schema that
1367: they complete. Otherwise, structure schemas can always be used without these
1.18 ! cvs 1368: extensions when the corresponding applications are not available.</p>
! 1369: </div>
1.1 cvs 1370:
1.18 ! cvs 1371: <div class="subsection">
1.1 cvs 1372:
1.18 ! cvs 1373: <h3><a name="sectc323">The general organization of structure schemas</a></h3>
! 1374: <p>
! 1375: Every structure schema begins with the keyword <tt>STRUCTURE</tt> and ends
! 1376: with the keyword <tt>END</tt>. The keyword <tt>STRUCTURE</tt> is followed by
! 1377: the keyword <tt>EXTENSION</tt> in the case where the schema defines an
1.1 cvs 1378: extension, then by the name of the generic structure which the schema defines
1379: (the name of the document or object class). The name of the structure is
1.18 ! cvs 1380: followed by a semicolon.</p>
! 1381: <p>
1.1 cvs 1382: In the case of a complete schema (that is, a schema which is not an
1383: extension), the definition of the name of the structure is followed by the
1384: declarations of the default presentation schema, the global attributes, the
1385: parameters, the structure rules, the associated elements, the units, the
1386: skeleton elements and the exceptions. Only the definition of the structure
1387: rules is required. Each series of declarations begins with a keyword:
1.18 ! cvs 1388: <tt>DEFPRES</tt>, <tt>ATTR</tt>, <tt>PARAM</tt>, <tt>STRUCT</tt>,
! 1389: <tt>ASSOC</tt>, <tt>UNITS</tt>, <tt>EXPORT</tt>, <tt>EXCEPT</tt>.</p>
! 1390: <p>
1.1 cvs 1391: In the case of an extension schema, there are neither parameters nor skeleton
1.18 ! cvs 1392: elements and the <tt>STRUCT</tt> section is optional, while that section is
1.1 cvs 1393: required in a schema that is not an extension. On the other hand, extension
1.18 ! cvs 1394: schemas can contain an <tt>EXTENS</tt> section, which must not appear in a
1.1 cvs 1395: schema which is not an extension; this section defines the complements to
1396: attach to the rules found in the schema to which the extension will be added.
1.18 ! cvs 1397: The sections <tt>ATTR</tt>, <tt>STRUCT</tt>, <tt>ASSOC</tt>, and
! 1398: <tt>UNITS</tt> define new attributes, new elements, new associated elements,
! 1399: and new units which add their definitions to the principal schema.</p>
! 1400: <pre> StructSchema ='STRUCTURE' ElemID ';'
1.1 cvs 1401: 'DEFPRES' PresID ';'
1402: [ 'ATTR' AttrSeq ]
1403: [ 'PARAM' RulesSeq ]
1404: 'STRUCT' RulesSeq
1405: [ 'ASSOC' RulesSeq ]
1406: [ 'UNITS' RulesSeq ]
1407: [ 'EXPORT' SkeletonSeq ]
1408: [ 'EXCEPT' ExceptSeq ]
1409: 'END' .
1.18 ! cvs 1410: ElemID = NAME .</pre>
! 1411: <p>
! 1412: or</p>
! 1413: <pre> ExtensSchema ='STRUCTURE' 'EXTENSION' ElemID ';'
1.1 cvs 1414: 'DEFPRES' PresID ';'
1415: [ 'ATTR' AttrSeq ]
1416: [ 'STRUCT' RulesSeq ]
1417: [ 'EXTENS' ExtensRuleSeq ]
1418: [ 'ASSOC' RulesSeq ]
1419: [ 'UNITS' RulesSeq ]
1420: [ 'EXCEPT' ExceptSeq ]
1421: 'END' .
1.18 ! cvs 1422: ElemID = NAME .</pre>
! 1423: </div>
1.1 cvs 1424:
1.18 ! cvs 1425: <div class="subsection">
1.1 cvs 1426:
1.18 ! cvs 1427: <h3><a name="sectc324">The default presentation</a></h3>
! 1428: <p>
! 1429: It was shown <a href="#mulpres">above</a> that many different presentations
1.1 cvs 1430: are possible for documents and objects of the same class. The structure
1.18 ! cvs 1431: schema defines a preferred presentation for the class, called the <em>default
! 1432: presentation</em>. Like generic structures, presentations are described by
! 1433: programs, called <em>presentation schemas</em>, which are written in a
! 1434: specific language, P, presented <a href="#sectb42">later</a> in this document.
! 1435: The name appearing after the keyword <tt>DEFPRES</tt> is the name of the
1.2 cvs 1436: default presentation schema. When a new document is created, Thot will use
1437: this presentation schema by default, but the user remains free to choose
1.18 ! cvs 1438: another if s/he wishes.</p>
! 1439: <pre> PresID = NAME .</pre>
! 1440: </div>
1.1 cvs 1441:
1.18 ! cvs 1442: <div class="subsection">
1.1 cvs 1443:
1.18 ! cvs 1444: <h3><a name="sectc325">Global Attributes</a></h3>
! 1445: <p>
1.1 cvs 1446: If the generic structure includes global attributes of its own, they are
1.18 ! cvs 1447: declared after the keyword <tt>ATTR</tt>. Each global attribute is defined by
1.1 cvs 1448: its name, followed by an equals sign and the definition of its type. The
1.18 ! cvs 1449: declaration of a global attribute is terminated by a semi-colon.</p>
! 1450: <p>
1.1 cvs 1451: For attributes of the numeric, textual, or reference types, the type is
1.18 ! cvs 1452: indicated by a keyword, <tt>INTEGER</tt>, <tt>TEXT</tt>, or <tt>REFERENCE</tt>
! 1453: respectively.</p>
! 1454: <p>
! 1455: In the case of a reference attribute, the keyword <tt>REFERENCE</tt> is
1.1 cvs 1456: followed by the type of the referenced element in parentheses. It can refer
1.18 ! cvs 1457: to any type at all, specified by using the keyword <tt>ANY</tt>, or to a
1.1 cvs 1458: specific type. In the latter case, the element type designated by the
1.18 ! cvs 1459: reference can be defined either in the <a href="#sectc327"><tt>STRUCT</tt>
! 1460: section</a> of the same structure schema or in the <tt>STRUCT</tt> section of
1.1 cvs 1461: another structure schema. When the type is defined in another schema, the
1462: element type is followed by the name of the structure schema (within
1463: parentheses) in which it is defined. The name of the designated element type
1.18 ! cvs 1464: can be preceded by the keyword <tt>First</tt> or <tt>Second</tt>, but only in
! 1465: the case where the type is defined as <a href="#sectd3285">a pair</a>. These
1.1 cvs 1466: keywords indicate whether the attribute must designate the first mark of the
1467: pair or the second. If the reference refers to a pair and neither of these
1.18 ! cvs 1468: two keywords is present, then the first mark is used.</p>
! 1469: <p>
1.1 cvs 1470: In the case of an enumeration attribute, the equals sign is followed by the
1471: list of names representing the possible values of the attribute, the names
1472: being separated from each other by commas. An enumeration attribute has at
1473: least one possible value; the maximum number of values is defined by the
1.18 ! cvs 1474: compiler for the S language.</p>
! 1475: <pre> AttrSeq = Attribute < Attribute > .
1.1 cvs 1476: Attribute = AttrID '=' AttrType ';' .
1477: AttrType = 'INTEGER' / 'TEXT' /
1478: 'REFERENCE' '(' RefType ')' /
1479: ValueSeq .
1480: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .
1481: FirstSec = 'First' / 'Second' .
1482: ExtStruct = '(' ElemID ')' .
1483: ValueSeq = AttrVal < ',' AttrVal > .
1484: AttrID = NAME .
1.18 ! cvs 1485: AttrVal = NAME .</pre>
! 1486: <p>
! 1487: There is a predefined global text attribute, the <em>language</em>, which is
1.2 cvs 1488: automatically added to every Thot structure schema. This attribute allows
1489: Thot to perform certain actions, such as hyphenation and spell-checking, which
1490: cannot be performed without knowing the language in which each part of the
1491: document is written. This attribute can be used just like any explicitly
1.18 ! cvs 1492: declared attribute: the system acts as if every structure schema contains</p>
! 1493: <pre>ATTR
! 1494: Language = TEXT;</pre>
! 1495: <blockquote class="example">
! 1496: <p>
! 1497: <strong>Example:</strong></p>
! 1498: <p>
1.2 cvs 1499: The following specification defines the global enumeration attribute
1.18 ! cvs 1500: WordType.</p>
! 1501: <pre>ATTR
! 1502: WordType = Definition, IndexWord, DocumentTitle;</pre>
! 1503: </blockquote>
! 1504: </div>
1.1 cvs 1505:
1.18 ! cvs 1506: <div class="subsection">
1.1 cvs 1507:
1.18 ! cvs 1508: <h3><a name="sectc326">Parameters</a></h3>
! 1509: <p>
1.1 cvs 1510: A parameter is a document element which can appear many times in the document,
1511: but always has the same value. This value can only be modified in a
1512: controlled way by certain applications. For example, in an advertising
1513: circular, the name of the recipient may appear in the address part and in the
1514: text of the circular. If the recipient's name were a parameter, it might only
1.18 ! cvs 1515: be able to be changed by a ``mail-merge'' application.</p>
! 1516: <p>
1.1 cvs 1517: Parameters are not needed for every document class, but if the schema includes
1.18 ! cvs 1518: parameters they are declared after the keyword <tt>PARAM</tt>. Each parameter
! 1519: declaration is made in the same way as a <a href="#sectc327">structure element
! 1520: declaration</a>.</p>
! 1521: <p>
1.1 cvs 1522: During editing, Thot permits the insertion of parameters wherever the
1523: structure schema allows; it also permits the removal of parameters which are
1524: already in the document but does not allow the modification of the parameter's
1.2 cvs 1525: content in any way. The content is generated automatically by Thot during the
1526: creation of the parameter, based on the value of the parameter in the
1.18 ! cvs 1527: document.</p>
! 1528: </div>
1.1 cvs 1529:
1.18 ! cvs 1530: <div class="subsection">
1.1 cvs 1531:
1.18 ! cvs 1532: <h3><a name="sectc327">Structured elements</a></h3>
! 1533: <p>
1.1 cvs 1534: The rules for defining structured elements are required, except in an
1535: extension schema: they constitute the core of a structure schema, since they
1536: define the structure of the different types of elements that occur in a
1.18 ! cvs 1537: document or object of the class defined by the schema.</p>
! 1538: <p>
! 1539: The first structure rule after the keyword <tt>STRUCT</tt> must define the
1.1 cvs 1540: structure of the class whose name appears in the first instruction
1.18 ! cvs 1541: (<tt>STRUCTURE</tt>) of the schema. This is the root rule of the schema,
! 1542: defining the root of the document tree or object tree.</p>
! 1543: <p>
1.1 cvs 1544: The remaining rules may be placed in any order, since the language permits the
1545: definition of element types before or after their use, or even in the same
1546: instruction in which they are used. This last case allows the definition of
1.18 ! cvs 1547: recursive structures.</p>
! 1548: <p>
1.1 cvs 1549: Each rule is composed of a name (the name of the element type whose structure
1.18 ! cvs 1550: is being defined) followed by an equals sign and a structure definition.</p>
! 1551: <p>
1.1 cvs 1552: If any local attributes are associated with the element type defined by the
1.2 cvs 1553: rule, they appear between parentheses after the type name and before the
1.18 ! cvs 1554: equals sign. The parentheses contain, first, the keyword <tt>ATTR</tt>, then
1.2 cvs 1555: the list of local attributes, separated by commas. Each local attribute is
1556: composed of the name of the attribute followed by an equals sign and the
1.18 ! cvs 1557: definition of the attribute's type, just as in the definition of <a
! 1558: href="#sectc325">global attributes</a>. The name of the attribute can be
1.2 cvs 1559: preceded by an exclamation point to indicate that the attribute must always be
1560: present for this element type. The same attribute, identified by its name,
1561: can be defined as a local attribute for multiple element types. In this
1562: case, the equals sign and definition of the attribute type need only appear in
1563: the first occurrence of the attribute. It should be noted that global
1.18 ! cvs 1564: attributes cannot also be defined as local attributes.</p>
! 1565: <p>
! 1566: If any <a href="#sectd3135">extensions</a> are defined for this element type,
! 1567: a plus sign follows the structure definition and the names of the extension
! 1568: element types appear between parentheses after the plus. If there are
! 1569: multiple extensions, they are separated by commas. These types can either be
! 1570: defined in the same schema, defined in other schemas, or they may be base
! 1571: types identified by the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>,
! 1572: <tt>SYMBOL</tt>, or <tt>PICTURE</tt>.</p>
! 1573: <p>
! 1574: <a href="#sectd3135">Restrictions</a> are indicated in the same manner as
! 1575: extensions, but they are introduced by a minus sign and they come after the
! 1576: extensions, or if there are no extensions, after the structure definition.</p>
! 1577: <p>
1.1 cvs 1578: If the values of attributes must be attached systematically to this element
1.18 ! cvs 1579: type, they are introduced by the keyword <tt>WITH</tt> and declared in the
1.1 cvs 1580: form of a list of fixed-value attributes. When such definitions of fixed
1.18 ! cvs 1581: attribute values appear, they are always the last part of the rule.</p>
! 1582: <p>
! 1583: The rule is terminated by a semicolon.</p>
! 1584: <pre> RuleSeq = Rule < Rule > .
1.1 cvs 1585: Rule = ElemID [ LocAttrSeq ] '=' DefWithAttr ';'.
1586: LocAttrSeq = '(' 'ATTR' LocAttr < ';' LocAttr > ')' .
1587: LocAttr = [ '!' ] AttrID [ '=' AttrType ] .
1588: DefWithAttr = Definition
1589: [ '+' '(' ExtensionSeq ')' ]
1590: [ '-' '(' RestrictSeq ')' ]
1591: [ 'WITH' FixedAttrSeq ] .
1592: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1593: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
1594: 'SYMBOL' / 'PICTURE' .
1595: RestrictSeq = RestrictElem < ',' RestrictElem > .
1596: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
1.18 ! cvs 1597: 'SYMBOL' / 'PICTURE' .</pre>
! 1598: <p>
1.1 cvs 1599: The list of fixed-value attributes is composed of a sequence of
1600: attribute-value pairs separated by commas. Each pair contains the name of the
1601: attribute and the fixed value for this element type, the two being separated
1602: by an equals sign. If the sign is preceded by a question mark the given value
1603: is only an initial value that may be modified later rather than a value fixed
1604: for all time. Reference attributes are an exception to this norm. They
1605: cannot be assigned a fixed value, but when the name of such an attribute
1606: appears this indicates that this element type must have a valid value for the
1.2 cvs 1607: attribute. For the other attribute types, the fixed value is indicated by a
1.1 cvs 1608: signed integer (numeric attributes), a character string between apostrophes
1.18 ! cvs 1609: (textual attributes) or the name of a value (enumeration attributes).</p>
! 1610: <p>
! 1611: Fixed-value attributes can either be <a href="#sectc325">global</a> or local
1.1 cvs 1612: to the element type for which they are fixed, but they must be declared before
1.18 ! cvs 1613: they are used.</p>
! 1614: <pre> FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 1615: FixedAttr = AttrID [ FixedOrModifVal ] .
1616: FixedOrModifVal = [ '?' ] '=' FixedValue .
1617: FixedValue = [ '-' ] NumValue / TextVal / AttrVal .
1618: NumValue = NUMBER .
1.18 ! cvs 1619: TextVal = STRING .</pre>
! 1620: </div>
1.1 cvs 1621:
1.18 ! cvs 1622: <div class="subsection">
1.1 cvs 1623:
1.18 ! cvs 1624: <h3><a name="sectc328">Structure definitions</a></h3>
! 1625: <p>
1.1 cvs 1626: The structure of an element type can be a simple base type or a constructed
1.18 ! cvs 1627: type.</p>
! 1628: <p>
1.1 cvs 1629: For constructed types, it is frequently the case that similar structures
1630: appear in many places in a document. For example the contents of the
1631: abstract, of the introduction, and of a section can have the same structure,
1632: that of a sequence of paragraphs. In this case, a single, common structure
1633: can be defined (the paragraph sequence in this example), and the schema is
1634: written to indicate that each element type possesses this structure, as
1.18 ! cvs 1635: follows:</p>
! 1636: <pre> Abstract = Paragraph_sequence;
1.1 cvs 1637: Introduction = Paragraph_sequence;
1.18 ! cvs 1638: Section_contents = Paragraph_sequence;</pre>
! 1639: <p>
! 1640: The equals sign means ``has the same structure as''.</p>
! 1641: <p>
1.1 cvs 1642: If the element type defined is a simple base type, this is indicated by one of
1.18 ! cvs 1643: the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>, <tt>SYMBOL</tt>, or
! 1644: <tt>PICTURE</tt>. If some local attributes must be associated with a base
1.1 cvs 1645: type, the keyword of the base type is followed by the declaration of the local
1.18 ! cvs 1646: attributes using the syntax <a href="#sectc327">presented above.</a></p>
! 1647: <p>
1.1 cvs 1648: In the case of an open choice, the type is indicated by the keyword
1.18 ! cvs 1649: <tt>UNIT</tt> for units or the keyword <tt>NATURE</tt> for objects having a
! 1650: structure defined by any other schema.</p>
! 1651: <p>
! 1652: A unit represents one of the two following categories:</p>
! 1653: <ul>
! 1654: <li>
! 1655: a base type: text, graphical element, symbol, picture,
! 1656: <li>
! 1657: an element whose type is chosen from among the types defined as units in the
! 1658: <tt>UNITS</tt> section of the document's structure schema. It can also be
! 1659: chosen from among the types defined as <a href="#sectd3132">units</a> in the
! 1660: <a href="#sectc3212"><tt>UNITS</tt> section</a> of the structure schemas that
1.2 cvs 1661: defines the ancestors of the element to which the rule is applied.
1.18 ! cvs 1662: </ul>
! 1663: <p>
1.2 cvs 1664: Before the creation of an element defined as a unit, Thot asks the user to
1.18 ! cvs 1665: choose between the categories of elements.</p>
! 1666: <p>
1.1 cvs 1667: Thus, the contents of a paragraph can be specified as a sequence of units,
1668: which will permit the inclusion in the paragraphs of character strings,
1669: symbols, and various elements, such as cross-references, if these are defined
1.18 ! cvs 1670: as units.</p>
! 1671: <p>
! 1672: A schema object (keyword <tt>NATURE</tt>) represents an object defined by a
1.1 cvs 1673: structure schema freely chosen from among the available schemas; in the case
1674: the element type is defined by the first rule (the root rule) of the chosen
1.18 ! cvs 1675: schema.</p>
! 1676: <p>
1.1 cvs 1677: If the element type defined is a constructed type, the list, aggregate,
1678: choice, and reference constructors are used. In this case the definition
1679: begins with a keyword identifying the constructor. This keyword is followed
1.18 ! cvs 1680: by a syntax specific to each constructor.</p>
! 1681: <p>
1.1 cvs 1682: The local attribute definitions appear after the name of the element type
1.18 ! cvs 1683: being defined, if this element type has <a href="#sectc327">local
! 1684: attributes</a>.</p>
! 1685: <pre> Definition = BaseType [ LocAttrSeq ] / Constr / Element .
1.1 cvs 1686: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' / 'PICTURE' /
1687: 'UNIT' / 'NATURE' .
1688: Element = ElemID [ ExtOrDef ] .
1689: ExtOrDef = 'EXTERN' / 'INCLUDED' /
1690: [ LocAttrSeq ] '=' Definition .
1691: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
1692: '(' DefWithAttr ')' /
1693: 'BEGIN' DefOptSeq 'END' /
1694: 'AGGREGATE' DefOptSeq 'END' /
1695: 'CASE' 'OF' DefSeq 'END' /
1696: 'REFERENCE' '(' RefType ')' /
1.18 ! cvs 1697: 'PAIR' .</pre>
1.1 cvs 1698:
1.18 ! cvs 1699: <div class="subsubsection">
1.1 cvs 1700:
1.18 ! cvs 1701: <h4><a name="sectd3281">List</a></h4>
! 1702: <p>
1.1 cvs 1703: The list constructor permits the definition of an element type composed of a
1704: list of elements, all of the same type. A list definition begins with the
1.18 ! cvs 1705: <tt>LIST</tt> keyword followed by an optional range, the keyword <tt>OF</tt>,
1.1 cvs 1706: and the definition, between parentheses, of the element type which must
1707: compose the list. The optional range is composed of the minimum and maximum
1708: number of elements for the list separated by two periods and enclosed by
1709: brackets. If the range is not present, the number of list elements is
1710: unconstrained. When only one of the two bounds of the range is unconstrained,
1711: it is represented by a star ('*') character. Even when both bounds are
1.18 ! cvs 1712: unconstrained, they can be specified by <tt>[*..*]</tt>, but it is simpler not
! 1713: to specify any bound.</p>
! 1714: <pre> 'LIST' [ '[' min '..' max ']' ]
1.1 cvs 1715: 'OF' '(' DefWithAttr ')'
1716: min = Integer / '*' .
1717: max = Integer / '*' .
1.18 ! cvs 1718: Integer = NUMBER .</pre>
! 1719: <p>
1.2 cvs 1720: Before the document is edited, Thot creates the minimum number of elements for
1721: the list. If no minimum was given, it creates a single element. If a maximum
1722: number of elements is given and that number is attained, the editor refuses to
1.18 ! cvs 1723: create new elements for the list.</p>
! 1724: <blockquote class="example">
! 1725: <p>
! 1726: <strong>Example:</strong></p>
! 1727: <p>
1.3 cvs 1728: The following two instructions define the body of a document as a sequence of
1729: at least two chapters and the contents of a section as a sequence of
1.18 ! cvs 1730: paragraphs. A single paragraph can be the entire contents of a section.</p>
! 1731: <pre>Body = LIST [2..*] OF (Chapter);
! 1732: Section_contents = LIST OF (Paragraph);</pre>
! 1733: </blockquote>
! 1734: </div>
1.1 cvs 1735:
1.18 ! cvs 1736: <div class="subsubsection">
1.1 cvs 1737:
1.18 ! cvs 1738: <h4><a name="sectd3282">Aggregate</a></h4>
! 1739: <p>
1.1 cvs 1740: The aggregate constructor is used to define an element type as a collection of
1741: sub-elements, each having a fixed type. The collection may be ordered or
1742: unordered. The elements composing the collection are called
1.18 ! cvs 1743: <em>components</em>. In the definition of an aggregate, a keyword indicates
! 1744: whether or not the aggregate is ordered: <tt>BEGIN</tt> for an ordered
! 1745: aggregate, <tt>AGGREGATE</tt> for an unordered aggregate. This keyword is
1.1 cvs 1746: followed by the list of component type definitions which is terminated by the
1.18 ! cvs 1747: <tt>END</tt> keyword. The component type definitions are separated by
! 1748: commas.</p>
! 1749: <p>
1.1 cvs 1750: Before creating an aggregate, the Thot editor creates all the aggregate's
1751: components in the order they appear in the structure schema, even for
1752: unordered aggregates. However, unlike ordered aggregates, the components of
1753: an unordered aggregate may be rearranged using operations of the Thot editor.
1754: The exceptions to the rule are any components whose name was preceded by a
1755: question mark character ('?'). These components, which are optional, can be
1756: created by explicit request, possibly at the time the aggregate is created,
1.18 ! cvs 1757: but they are not created automatically <em>prior</em> to the creation of the
! 1758: aggregate.</p>
! 1759: <pre> 'BEGIN' DefOptSeq 'END'
1.1 cvs 1760: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.18 ! cvs 1761: DefOpt = [ '?' ] DefWithAttr .</pre>
! 1762: <blockquote class="example">
! 1763: <p>
! 1764: <strong>Example:</strong></p>
! 1765: <p>
1.3 cvs 1766: In a bilingual document, each paragraph has an English version and a French
1767: version. In certain cases, the translator wants to add a marginal note, but
1768: this note is present in very few paragraphs. Thus, it must not be created
1769: systematically for every paragraph. A bilingual paragraph of this type is
1.18 ! cvs 1770: declared:</p>
! 1771: <pre>Bilingual_paragraph = BEGIN
1.1 cvs 1772: French_paragraph = TEXT;
1773: English_paragraph = TEXT;
1774: ? Note = TEXT;
1.18 ! cvs 1775: END;</pre>
! 1776: </blockquote>
! 1777: </div>
1.1 cvs 1778:
1.18 ! cvs 1779: <div class="subsubsection">
1.1 cvs 1780:
1.18 ! cvs 1781: <h4><a name="sectd3283">Choice</a></h4>
! 1782: <p>
1.1 cvs 1783: The choice constructor permits the definition of an element type which is
1.18 ! cvs 1784: chosen from among a set of possible types. The keywords <tt>CASE</tt> and
! 1785: <tt>OF</tt> are followed by a list of definitions of possible types, which are
! 1786: separated by semicolons and terminated by the <tt>END</tt> keyword.</p>
! 1787: <pre> 'CASE' 'OF' DefSeq 'END'
! 1788: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .</pre>
! 1789: <p>
1.1 cvs 1790: Before the creation of an element defined as a choice, the Thot editor
1791: presents the list of possible types for the element to the user. The user has
1.18 ! cvs 1792: only to select the element type that s/he wants to create from this list.</p>
! 1793: <p>
1.1 cvs 1794: The order of the type declarations is important. It determines the order of
1795: the list presented to the user before the creation of the element. Also, when
1796: a Choice element is being created automatically, the first type in the list is
1797: used. In fact, using the Thot editor, when an empty Choice element is
1798: selected, it is possible to select this element and to enter its text from
1799: keyboard. In this case, the editor uses the first element type which can
1.18 ! cvs 1800: contain an atom of the character string type.</p>
! 1801: <p>
! 1802: The two special cases of the choice constructor, the <a
! 1803: href="#sectc328"><em>schema</em></a> and the <a
! 1804: href="#sectc3212"><em>unit</em></a> are discussed elsewhere.</p>
! 1805: <blockquote class="example">
! 1806: <p>
! 1807: <strong>Example:</strong></p>
! 1808: <p>
1.3 cvs 1809: It is common in documents to treat a variety of objects as if they were
1810: ordinary paragraphs. Thus, a ``Paragraph'' might actually be composed of a
1811: block of text (an ordinary paragraph), or a mathematical formula whose
1812: structure is defined by another structure schema named Math, or a table, also
1813: defined by another structure schema. Here is a definition of such a
1.18 ! cvs 1814: paragraph:</p>
! 1815: <pre>Paragraph = CASE OF
1.1 cvs 1816: Simple_text = TEXT;
1817: Formula = Math;
1818: Table_para = Table;
1.18 ! cvs 1819: END;</pre>
! 1820: </blockquote>
! 1821: </div>
1.1 cvs 1822:
1.18 ! cvs 1823: <div class="subsubsection">
1.1 cvs 1824:
1.18 ! cvs 1825: <h4><a name="sectd3284">Reference</a></h4>
! 1826: <p>
1.1 cvs 1827: Like all elements in Thot, references are typed. An element type defined as a
1828: reference is a cross-reference to an element of some other given type. The
1.18 ! cvs 1829: keyword <tt>REFERENCE</tt> is followed by the name of a type enclosed in
1.1 cvs 1830: parentheses. When the type which is being cross-referenced is defined in
1831: another structure schema, the type name is itself followed by the name of the
1.18 ! cvs 1832: external structure schema in which it is defined.</p>
! 1833: <p>
! 1834: When the designated element type is a <a href="#sectd3285">mark pair</a>, it
! 1835: can be preceded by a <tt>FIRST</tt> or <tt>SECOND</tt> keyword. These
! 1836: keywords indicate whether the reference points to the first or second mark of
! 1837: the pair. If the reference points to a pair and neither of these two keywords
! 1838: is present, the reference is considered to point to the first mark of the
! 1839: pair.</p>
! 1840: <p>
1.1 cvs 1841: There is an exception to the principle of typed references: it is possible to
1842: define a reference which designates an element of any type, which can either
1843: be in the same document or another document. In this case, it suffices to put
1.18 ! cvs 1844: the keyword <tt>ANY</tt> in the parentheses which indicate the referenced
! 1845: element type.</p>
! 1846: <pre> 'REFERENCE' '(' RefType ')'
! 1847: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .</pre>
! 1848: <p>
! 1849: When defining an inclusion, the <tt>REFERENCE</tt> keyword is not used.
1.1 cvs 1850: Inclusions with complete expansion are not declared as such in the structure
1851: schemas, since any element defined in a structure schema can be replaced by an
1852: element of the same type. Instead, inclusions without expansion or with
1853: partial expansion must be declared explicitly whenever they will include a
1854: complete object ( and not a part of an object). In this case, the object type
1855: to be included (that is, the name of its structure schema) is followed by a
1.18 ! cvs 1856: keyword: <tt>EXTERN</tt> for inclusion without expansion and <tt>INCLUDED</tt>
! 1857: for partial expansion.</p>
! 1858: <p>
1.1 cvs 1859: Before creating a cross-reference or an inclusion, the Thot editor asks the
1860: user to choose, from the document images displayed, the referenced or included
1.18 ! cvs 1861: element.</p>
! 1862: <blockquote class="example">
! 1863: <p>
! 1864: <strong>Example:</strong></p>
! 1865: <p>
1.3 cvs 1866: If the types Note and Section are defined in the Article structure schema, it
1867: is possible to define, in the same structure schema, a reference to a note and
1.18 ! cvs 1868: a reference to a section in this manner:</p>
! 1869: <pre>Ref_note = REFERENCE (Note);
! 1870: Ref_section = REFERENCE (Section);</pre>
! 1871: <p>
1.1 cvs 1872: It is also possible to define the generic structure of a collection of
1873: articles, which include (with partial expansion) objects of the Article class
1874: and which possess an introduction which may include cross-references to
1875: sections of the included articles. In the Collection structure schema, the
1.18 ! cvs 1876: definitions are:</p>
! 1877: <pre>Collection = BEGIN
1.6 cvs 1878: Collection_title = TEXT;
1879: Introduction = LIST OF (Elem = CASE OF
1.1 cvs 1880: TEXT;
1881: Ref_sect;
1882: END);
1.6 cvs 1883: Body = LIST OF (Article INCLUDED);
1884: END;
1.18 ! cvs 1885: Ref_sect = REFERENCE (Section (Article));</pre>
! 1886: <p>
1.1 cvs 1887: Here we define a Folder document class which has a title and includes
1.18 ! cvs 1888: documents of different types, particularly Folders:</p>
! 1889: <pre>Folder = BEGIN
1.6 cvs 1890: Folder_title = TEXT;
1891: Folder_contents = LIST OF (Document);
1892: END;
1.1 cvs 1893:
1894: Document = CASE OF
1895: Article EXTERN;
1896: Collection EXTERN;
1897: Folder EXTERN;
1.18 ! cvs 1898: END;</pre>
! 1899: <p>
1.1 cvs 1900: Under this definition, Folder represents either an aggregate which contains a
1901: folder title and the list of included documents or an included folder. To
1902: resolve this ambiguity, in the P language, the placement of a star character
1.18 ! cvs 1903: in front of the type name (here, Folder) indicates an included document.</p>
! 1904: </blockquote>
! 1905: </div>
1.1 cvs 1906:
1.18 ! cvs 1907: <div class="subsubsection">
1.1 cvs 1908:
1.18 ! cvs 1909: <h4><a name="sectd3285">Mark pairs</a></h4>
! 1910: <p>
1.1 cvs 1911: Like other elements, mark pairs are typed. The two marks of the pair have the
1912: same type, but there exist two predefined subtypes which apply to all mark
1.18 ! cvs 1913: pairs: the first mark of the pair (called <tt>First</tt> in the P and T
! 1914: languages) and the second mark (called <tt>Second</tt>).</p>
! 1915: <p>
! 1916: In the S language, a mark pair is noted simply by the <tt>PAIR</tt>
! 1917: keyword.</p>
! 1918: <p>
1.1 cvs 1919: In the Thot editor, marks are always moved or destroyed together. The two
1920: marks of a pair have the same identifier, unique within the document, which
1.18 ! cvs 1921: permits intertwining mark pairs without risk of ambiguity.</p>
! 1922: </div>
! 1923: </div>
1.1 cvs 1924:
1.18 ! cvs 1925: <div class="subsection">
1.1 cvs 1926:
1.18 ! cvs 1927: <h3><a name="sectc329">Imports</a></h3>
! 1928: <p>
1.1 cvs 1929: Because of schema constructors, it is possible, before editing a document, to
1930: use classes defined by other structure schemas whenever they are needed. It is
1931: also possible to assign specific document classes to certain element types. In
1932: this case, these classes are simply designated by their name. In fact, if a
1933: type name is not defined in the structure schema, it is assumed that it
1.18 ! cvs 1934: specifies a structure defined by another structure schema.</p>
! 1935: <blockquote class="example">
! 1936: <p>
! 1937: <strong>Example:</strong></p>
! 1938: <p>
1.3 cvs 1939: If the types Math and Table don't appear in the left part of a structure rule
1940: in the schema, the following two rules indicate that a formula has the
1941: structure of an object defined by the structure schema Math and that a table
1.18 ! cvs 1942: element has the structure of an object defined by the Table schema.</p>
! 1943: <pre>Formula = Math;
! 1944: Table_elem = Table;</pre>
! 1945: </blockquote>
! 1946: </div>
! 1947:
! 1948: <div class="subsection">
! 1949:
! 1950: <h3><a name="sectc3210">Extension rules</a></h3>
! 1951: <p>
! 1952: The <tt>EXTENS</tt> section, which can only appear in an extension schema,
1.1 cvs 1953: defines complements to the rules in the primary schema (i.e. the structure
1954: schema to which the extension schema will be applied). More precisely, this
1955: section permits the addition to an existing type of local attributes,
1.18 ! cvs 1956: extensions, restrictions and fixed-value attributes.</p>
! 1957: <p>
1.1 cvs 1958: These additions can be applied to the root rule of the primary schema,
1.18 ! cvs 1959: designated by the keyword <tt>Root</tt>, or to any other explicitly named
! 1960: rule.</p>
! 1961: <p>
1.1 cvs 1962: Extension rules are separated from each other by a semicolon and each
1.18 ! cvs 1963: extension rule has the same syntax as a <a href="#sectc327">structure
! 1964: rule</a>, but the part which defines the constructor is absent.</p>
! 1965: <pre> ExtenRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.6 cvs 1966: ExtensRule = RootOrElem [ LocAttrSeq ]
1967: [ '+' '(' ExtensionSeq ')' ]
1968: [ '-' '(' RestrictSeq ')' ]
1969: [ 'WITH' FixedAttrSeq ] .
1.18 ! cvs 1970: RootOrElem = 'Root' / ElemID .</pre>
! 1971: </div>
1.1 cvs 1972:
1.18 ! cvs 1973: <div class="subsection">
1.1 cvs 1974:
1.18 ! cvs 1975: <h3><a name="sectc3211">Associated elements</a></h3>
! 1976: <p>
1.1 cvs 1977: If associated elements are necessary, they must be declared in a specific
1.18 ! cvs 1978: section of the structure schema, introduced by the keyword <tt>ASSOC</tt>.
1.1 cvs 1979: Each associated element type is specified like any other structured element.
1980: However, these types must not appear in any other element types of the schema,
1.18 ! cvs 1981: except in <tt>REFERENCE</tt> rules.</p>
! 1982: </div>
1.1 cvs 1983:
1.18 ! cvs 1984: <div class="subsection">
1.1 cvs 1985:
1.18 ! cvs 1986: <h3><a name="sectc3212">Units</a></h3>
! 1987: <p>
! 1988: The <tt>UNITS</tt> section of the structure schema contains the declarations
1.1 cvs 1989: of the element types which can be used in the external objects making up parts
1990: of the document or in objects of the class defined by the schema. As with
1991: associated elements, these element types are defined just like other
1992: structured element types. They can be used in the other element types of the
1.18 ! cvs 1993: schema, but they can also be used in any other rule of the schema.</p>
! 1994: <blockquote class="example">
! 1995: <p>
! 1996: <strong>Example:</strong></p>
! 1997: <p>
! 1998: If references to notes are declared as units:</p>
! 1999: <pre>UNITS
! 2000: Ref_note = REFERENCE (Note);</pre>
! 2001: <p>
1.3 cvs 2002: then it is possible to use references to notes in a cell of a table, even when
1.18 ! cvs 2003: <tt>Table</tt> is an external structure schema. The <tt>Table</tt> schema
! 2004: must declare a cell to be a sequence of units, which can then be base element
! 2005: types (text, for example) or references to notes in the document.</p>
! 2006: <pre>Cell = LIST OF (UNITS);</pre>
! 2007: </blockquote>
! 2008: </div>
1.1 cvs 2009:
1.18 ! cvs 2010: <div class="subsection">
1.1 cvs 2011:
1.18 ! cvs 2012: <h3><a name="sectc3213">Skeleton elements</a></h3>
! 2013: <p>
1.1 cvs 2014: When editing a document which contains or must contain external references to
2015: several other documents, it may be necessary to load a large number of
2016: documents, simply to see the parts designated by the external references of
2017: the document while editing, or to access the source of included elements. In
2018: this case, the external documents are not modified and it is only necessary to
2019: see the elements of these documents which could be referenced. Because of
2020: this, the editor will suggest that the documents be loaded in ``skeleton''
2021: form. This form contains only the elements of the document explicitly
1.18 ! cvs 2022: mentioned in the <tt>EXPORT</tt> section of their structure schema and, for
1.1 cvs 2023: these elements, only the part of the contents specified in that section. This
2024: form has the advantage of being very compact, thus requiring very few
2025: resources from the editor. This is also the skeleton form which constitutes
1.18 ! cvs 2026: the expanded form of <a href="#inclusion">inclusions</a> with partial
! 2027: expansion.</p>
! 2028: <p>
! 2029: Skeleton elements must be declared explicitly in the <tt>EXPORT</tt> section
1.1 cvs 2030: of the structure schema that defines them. This section begins with the
1.18 ! cvs 2031: keyword <tt>EXPORT</tt> followed by a comma-separated list of the element
1.1 cvs 2032: types which must appear in the skeleton form and ending with a semicolon.
1.18 ! cvs 2033: These types must have been previously declared in the schema.</p>
! 2034: <p>
1.1 cvs 2035: For each skeleton element type, the part of the contents which is loaded by
2036: the editor, and therefore displayable, can be specified by putting the keyword
1.18 ! cvs 2037: <tt>WITH</tt> and the name of the contained element type to be loaded after
1.1 cvs 2038: the name of the skeleton element type. In this case only that named element,
2039: among all the elements contained in the exportable element type, will be
1.18 ! cvs 2040: loaded. If the <tt>WITH</tt> is absent, the entire contents of the skeleton
1.1 cvs 2041: element will be loaded by the editor. If instead, it is better that the
2042: skeleton form not load the contents of a particular element type, the keyword
1.18 ! cvs 2043: <tt>WITH</tt> must be followed by the word <tt>Nothing</tt>.</p>
! 2044: <pre> [ 'EXPORT' SkeletonSeq ]
1.1 cvs 2045:
2046: SkeletonSeq = SkelElem < ',' SkelElem > ';' .
2047: SkelElem = ElemID [ 'WITH' Contents ] .
1.18 ! cvs 2048: Contents = 'Nothing' / ElemID [ ExtStruct ] .</pre>
! 2049: <blockquote class="example">
! 2050: <p>
! 2051: <strong>Example:</strong></p>
! 2052: <p>
1.3 cvs 2053: Suppose that, in documents of the article class, the element types
2054: Article_title, Figure, Section, Paragraph, and Biblio should appear in the
2055: skeleton form in order to make it easier to create external references to them
2056: from other documents. When loading an article in its skeleton form, all of
2057: these element types will be loaded except for paragraphs, but only the article
1.18 ! cvs 2058: title will be loaded in its entirety. For figures, the caption will be
! 2059: loaded, while for sections, the title will be loaded, and for bibliographic
! 2060: entries, only the title that they contain will be loaded. Note that
1.3 cvs 2061: bibliographic elements are defined in another structure schema, RefBib. To
2062: produce this result, the following declarations should be placed in the
1.18 ! cvs 2063: Article structure schema:</p>
! 2064: <pre>EXPORT
1.1 cvs 2065: Article_title,
1.5 cvs 2066: Figure With Caption,
1.1 cvs 2067: Section With Section_title,
2068: Paragraph With Nothing,
1.18 ! cvs 2069: Biblio With Biblio_title(RefBib);</pre>
! 2070: </blockquote>
! 2071: </div>
1.1 cvs 2072:
1.18 ! cvs 2073: <div class="subsection">
1.1 cvs 2074:
1.18 ! cvs 2075: <h3><a name="sectc3214">Exceptions</a></h3>
! 2076: <p>
1.1 cvs 2077: The behavior of the Thot editor and the actions that it performs are
2078: determined by the structure schemas. These actions are applied to all
2079: document and object types in accordance with their generic structure. For
2080: certain object types, such as tables and graphics, these actions are not
2081: sufficient or are poorly adapted and some special actions must be added to or
2082: substituted for certain standard actions. These special actions are called
1.18 ! cvs 2083: <em>exceptions</em>.</p>
! 2084: <p>
1.1 cvs 2085: Exceptions only inhibit or modify certain standard actions, but they can be
1.18 ! cvs 2086: used freely in every structure schema.</p>
! 2087: <p>
1.1 cvs 2088: Each structure schema can contain a section defining exceptions. It begins
1.18 ! cvs 2089: with the keyword <tt>EXCEPT</tt> and is composed of a sequence of exception
1.1 cvs 2090: declarations, separated by semicolons. Each declaration of an exception
2091: begins with the name of an element type or attribute followed by a colon. This
2092: indicates the element type or attribute to which the following exceptions
1.18 ! cvs 2093: apply. When the given element type name is a <a href="#sectd3285">mark
! 2094: pair</a>, and only in this case, the type name can be preceded by the keyword
! 2095: <tt>First</tt> or <tt>Second</tt>, to indicate if the exceptions which follow
1.1 cvs 2096: are associated with the first mark of the pair or the second. In the absence
1.18 ! cvs 2097: of this keyword, the first mark is used.</p>
! 2098: <p>
! 2099: When placed in an <a href="#sectc322">extension schema</a>, the keyword
! 2100: <tt>EXTERN</tt> indicates that the type name which follows is found in the
1.1 cvs 2101: principal schema (the schema being extended by the extension schema). The
1.18 ! cvs 2102: exceptions are indicated by a name. They are separated by semicolons.</p>
! 2103: <pre> [ 'EXCEPT' ExceptSeq ]
1.1 cvs 2104:
2105: ExceptSeq = Except ';' < Except ';' > .
2106: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr
2107: ':' ExcValSeq .
2108: ExcTypeOrAttr = ElemID / AttrID .
2109: ExcValSeq = ExcValue < ',' ExcValue > .
2110: ExcValue ='NoCut' / 'NoCreate' /
2111: 'NoHMove' / 'NoVMove' / 'NoMove' /
2112: 'NoHResize' / 'NoVResize' / 'NoResize' /
1.18 ! cvs 2113: 'MoveResize' /
1.1 cvs 2114: 'NewWidth' / 'NewHeight' /
2115: 'NewHPos' / 'NewVPos' /
2116: 'Invisible' / 'NoSelect' /
2117: 'Hidden' / 'ActiveRef' /
2118: 'ImportLine' / 'ImportParagraph' /
2119: 'NoPaginate' / 'ParagraphBreak' /
1.9 cvs 2120: 'HighlightChildren' / 'ExtendedSelection' /
1.18 ! cvs 2121: 'ReturnCreateNL' .</pre>
! 2122: <p>
! 2123: The following are the available exceptions:</p>
! 2124: <dl>
! 2125: <dt><tt>NoCut</tt></dt>
! 2126: <dd>
! 2127: This exception can only be applied to element types. Elements of a type to
1.13 cvs 2128: which this exception is applied cannot be deleted by the editor.
1.18 ! cvs 2129: </dd>
! 2130: <dt><tt>NoCreate</tt></dt>
! 2131: <dd>
! 2132: This exception can only be applied to element types. Elements of a type to
1.2 cvs 2133: which this exception is applied cannot be created by ordinary commands for
2134: creating new elements. These elements are usually created by special actions
1.13 cvs 2135: associated with other exceptions.
1.18 ! cvs 2136: </dd>
! 2137: <dt><tt>NoHMove</tt></dt>
! 2138: <dd>
! 2139: This exception can only be applied to element types. Elements of a type to
! 2140: which this exception is applied cannot be moved horizontally with the mouse.
! 2141: Their children elements cannot be moved either.
! 2142: </dd>
! 2143: <dt><tt>NoVMove</tt></dt>
! 2144: <dd>
! 2145: This exception can only be applied to element types. Elements of a type to
! 2146: which this exception is applied cannot be moved vertically with the mouse.
! 2147: Their children elements cannot be moved either.
! 2148: </dd>
! 2149: <dt><tt>NoMove</tt></dt>
! 2150: <dd>
! 2151: This exception can only be applied to element types. Elements of a type to
1.2 cvs 2152: which this exception is applied cannot be moved in any direction with the
1.13 cvs 2153: mouse. Their children elements cannot be moved either.
1.18 ! cvs 2154: </dd>
! 2155: <dt><tt>NoHResize</tt></dt>
! 2156: <dd>
! 2157: This exception can only be applied to element types. Elements of a type to
! 2158: which this exception is applied cannot be resized horizontally with the mouse.
! 2159: Their children elements cannot be resized either.
! 2160: </dd>
! 2161: <dt><tt>NoVResize</tt></dt>
! 2162: <dd>
! 2163: This exception can only be applied to element types. Elements of a type to
! 2164: which this exception is applied cannot be resized vertically with the mouse.
! 2165: Their children elements cannot be resized either.
! 2166: </dd>
! 2167: <dt><tt>NoResize</tt></dt>
! 2168: <dd>
! 2169: This exception can only be applied to element types. Elements of a type to
1.2 cvs 2170: which this exception is applied cannot be resized in any direction with the
1.13 cvs 2171: mouse. Their children elements cannot be resized either.
1.18 ! cvs 2172: </dd>
! 2173: <dt><tt>MoveResize</tt></dt>
! 2174: <dd>
! 2175: This exception can only be applied to element types. Elements of a type to
! 2176: which this exception is applied can be moved and resized in any direction with
! 2177: the mouse, even if one of their ancestor element has an exception that
1.13 cvs 2178: prevents moving or resizing. Their children elements can also be resized or
2179: moved.
1.18 ! cvs 2180: </dd>
! 2181: <dt><tt>NoSelect</tt></dt>
! 2182: <dd>
! 2183: This exception can only be applied to element types. Elements of a type to
! 2184: which this exception is applied cannot be selected directly with the mouse,
! 2185: but they can be selected by other methods provided by the editor.
! 2186: </dd>
! 2187: <dt><tt>NewWidth</tt></dt>
! 2188: <dd>
! 2189: This exception can only be applied to numeric attributes. If the width of an
! 2190: element which has this attribute is modified with the mouse, the value of the
! 2191: new width will be assigned to the attribute.
! 2192: </dd>
! 2193: <dt><tt>NewHeight</tt></dt>
! 2194: <dd>
! 2195: This exception can only be applied to numeric attributes. If the height of an
! 2196: element which has this attribute is modified with the mouse, the value of the
! 2197: new height will be assigned to the attribute.
! 2198: </dd>
! 2199: <dt><tt>NewHPos</tt></dt>
! 2200: <dd>
! 2201: This exception can only be applied to numeric attributes. If the horizontal
! 2202: position of an element which has this attribute is modified with the mouse,
! 2203: the value of the new horizontal position will be assigned to the attribute.
! 2204: </dd>
! 2205: <dt><tt>NewVPos</tt></dt>
! 2206: <dd>
! 2207: This exception can only be applied to numeric attributes. If the vertical
! 2208: position of an element which has this attribute is modified with the mouse,
! 2209: the value of the new vertical position will be assigned to the attribute.
! 2210: </dd>
! 2211: <dt><tt>Invisible</tt></dt>
! 2212: <dd>
! 2213: This exception can only be applied to attributes, but can be applied to all
1.2 cvs 2214: attribute types. It indicates that the attribute must not be seen by the user
2215: and that its value must not be changed directly. This exception is usually
1.5 cvs 2216: used when another exception manipulates the value of an attribute.
1.18 ! cvs 2217: </dd>
! 2218: <dt><tt>Hidden</tt></dt>
! 2219: <dd>
! 2220: This exception can only be applied to element types. It indicates that
1.2 cvs 2221: elements of this type, although present in the document's structure, must not
1.18 ! cvs 2222: be shown to the user of the editor. In particular, the creation menus must
! 2223: not propose this type and the selection message must not pick it.
! 2224: </dd>
! 2225: <dt><tt>ActiveRef</tt></dt>
! 2226: <dd>
! 2227: This exception can only be applied to attributes of the reference type. It
1.2 cvs 2228: indicates that when the user of the editor makes a double click on an element
2229: which possesses a reference attribute having this exception, the element
2230: designated by the reference attribute will be selected.
1.18 ! cvs 2231: </dd>
! 2232: <dt><tt>ImportLine</tt></dt>
! 2233: <dd>
! 2234: This exception can only be applied to element types. It indicates that
1.2 cvs 2235: elements of this type should receive the content of imported text files. An
2236: element is created for each line of the imported file. A structure schema
1.18 ! cvs 2237: cannot contain several exceptions <tt>ImportLine</tt> and, if it contains one,
! 2238: it should not contain any exception <tt>ImportParagraph</tt>.
! 2239: </dd>
! 2240: <dt><tt>ImportParagraph</tt></dt>
! 2241: <dd>
! 2242: This exception can only be applied to element types. It indicates that
1.2 cvs 2243: elements of this type should receive the content of imported text files. An
2244: element is created for each paragraph of the imported file. A paragraph is a
2245: sequence of lines without any empty line. A structure schema cannot contain
1.18 ! cvs 2246: several exceptions <tt>ImportParagraph</tt> and, if it contains one, it should
! 2247: not contain any exception <tt>ImportLine</tt>.
! 2248: </dd>
! 2249: <dt><tt>NoPaginate</tt></dt>
! 2250: <dd>
! 2251: This exception can only be applied to the root element, i.e. the name that
! 2252: appear after the keyword <tt>STRUCTURE</tt> at the beginning of the structure
1.2 cvs 2253: schema. It indicates that the editor should not allow the user to paginate
1.1 cvs 2254: documents of that type.
1.18 ! cvs 2255: </dd>
! 2256: <dt><tt>ParagraphBreak</tt></dt>
! 2257: <dd>
! 2258: This exception can only be applied to element types. When the caret is within
! 2259: an element of a type to which this exception is applied, it is that element
! 2260: that will be split when the user hits the Return key.
! 2261: </dd>
! 2262: <dt><tt>ReturnCreateNL</tt></dt>
! 2263: <dd>
! 2264: This exception can only be applied to element types. When the caret is within
! 2265: an element of a type to which this exception is applied, the Return key simply
! 2266: inserts a New line character (code \212) at the current position. The Return
! 2267: key does not create a new element; it does not split the current element
! 2268: either.
! 2269: </dd>
! 2270: <dt><tt>HighlightChildren</tt></dt>
! 2271: <dd>
! 2272: This exception can only be applied to element types. Elements of a type to
1.2 cvs 2273: which this exception is applied are not highlighted themselves when they are
2274: selected, but all their children are highlighted instead.
1.18 ! cvs 2275: </dd>
! 2276: <dt><tt>ExtendedSelection</tt></dt>
! 2277: <dd>
! 2278: This exception can only be applied to element types. The selection extension
! 2279: command (middle button of the mouse) only add the clicked element (if it has
! 2280: that exception) to the current selection, without selecting other elements
! 2281: between the current selection and the clicked element.
! 2282: </dd>
! 2283: </dl>
! 2284: <blockquote class="example">
! 2285: <p>
! 2286: <strong>Example:</strong></p>
! 2287: <p>
1.3 cvs 2288: Consider a structure schema for object-style graphics which defines the
1.18 ! cvs 2289: Graphic_object element type with the associated Height and Weight numeric
! 2290: attributes. Suppose that we want documents of this class to have the
! 2291: following qualities:</p>
! 2292: <ul>
! 2293: <li>
! 2294: Whenever the width or height of an object is changed using the mouse, the new
! 2295: values are stored in the object's Width and Height attributes.
! 2296: <li>
! 2297: The user should not be able to change the values of the Width and Height
1.5 cvs 2298: attributes via the Attributes menu of the Thot editor.
1.18 ! cvs 2299: </ul>
! 2300: <p>
! 2301: The following exceptions will produce this effect.</p>
! 2302: <pre>STRUCT
1.1 cvs 2303: ...
1.5 cvs 2304: Graphics_object (ATTR Height = Integer; Width = Integer)
1.1 cvs 2305: = GRAPHICS with Height ?= 10, Width ?= 10;
2306: ...
2307: EXCEPT
2308: Height: NewHeight, Invisible;
1.18 ! cvs 2309: Width: NewWidth, Invisible;</pre>
! 2310: </blockquote>
! 2311: </div>
! 2312: </div>
1.1 cvs 2313:
1.18 ! cvs 2314: <div class="section">
1.1 cvs 2315:
1.18 ! cvs 2316: <h2><a name="sectb33">Some examples</a></h2>
! 2317: <p>
1.1 cvs 2318: In order to illustrate the principles of the document model and the syntax of
2319: the S language, this section presents two examples of structure schemas. One
1.18 ! cvs 2320: defines a class of documents, the other defines a class of objects.</p>
1.1 cvs 2321:
1.18 ! cvs 2322: <div class="subsection">
1.1 cvs 2323:
1.18 ! cvs 2324: <h3><a name="sectc331">A class of documents: articles</a></h3>
! 2325: <p>
1.1 cvs 2326: This example shows a possible structure for articles published in a journal.
1.18 ! cvs 2327: Text between braces is comments.</p>
! 2328: <pre>STRUCTURE Article; { This schema defines the Article class }
1.1 cvs 2329: DEFPRES ArticleP; { The default presentation schema is
2330: ArticleP }
2331: ATTR { Global attribute definitions }
2332: WordType = Definition, IndexWord, DocumentTitle;
2333: { A single global attribute is defined, with three values }
2334: STRUCT { Definition of the generic structure }
2335: Article = BEGIN { The Article class has an aggregate
2336: structure }
2337: Title = BEGIN { The title is an aggregate }
2338: French_title =
2339: Text WITH Language='Fran\347ais';
2340: English_title =
2341: Text WITH Language='English';
2342: END;
2343: Authors =
2344: LIST OF (Author
2345: (ATTR Author_type=principal,secondary)
2346: { The Author type has a local attribute }
2347: = BEGIN
2348: Author_name = Text;
2349: Info = Paragraphs ;
2350: { Paragraphs is defined later }
2351: Address = Text;
2352: END
2353: );
2354: Keywords = Text;
2355: { The journal's editor introduces the article
2356: with a short introduction, in French and
2357: in English }
2358: Introduction =
2359: BEGIN
2360: French_intr = Paragraphs WITH
2361: Language='Fran\347ais';
2362: English_intr = Paragraphs WITH
2363: Language='English';
2364: END;
2365: Body = Sections; { Sections are defined later }
2366: { Appendixes are only created on demand }
2367: ? Appendices =
2368: LIST OF (Appendix =
2369: BEGIN
2370: Appendix_Title = Text;
2371: Appendix_Contents = Paragraphs;
2372: END
2373: );
2374: END; { End of the Article aggregate }
2375:
2376: Sections = LIST [2..*] OF (
2377: Section = { At least 2 sections }
2378: BEGIN
2379: Section_title = Text;
2380: Section_contents =
2381: BEGIN
2382: Paragraphs;
2383: Sections; { Sections at a lower level }
2384: END;
2385: END
2386: );
2387:
2388: Paragraphs = LIST OF (Paragraph = CASE OF
2389: Enumeration =
2390: LIST [2..*] OF
2391: (Item = Paragraphs);
2392: Isolated_formula = Formula;
2393: LIST OF (UNIT);
2394: END
2395: );
2396:
2397: ASSOC { Associated elements definitions }
2398:
2399: Figure = BEGIN
1.5 cvs 2400: Figure_caption = Text;
1.1 cvs 2401: Illustration = NATURE;
2402: END;
2403:
2404: Biblio_citation = CASE OF
2405: Ref_Article =
2406: BEGIN
2407: Authors_Bib = Text;
2408: Article_Title = Text;
2409: Journal = Text;
2410: Page_Numbers = Text;
2411: Date = Text;
2412: END;
2413: Ref_Livre =
2414: BEGIN
2415: Authors_Bib; { Defined above }
2416: Book_Title = Text;
2417: Editor = Text;
2418: Date; { Defined above }
2419: END;
2420: END;
2421:
2422: Note = Paragraphs - (Ref_note);
2423:
2424: UNITS { Elements which can be used in objects }
2425:
2426: Ref_note = REFERENCE (Note);
2427: Ref_biblio = REFERENCE (Biblio_citation);
2428: Ref_figure = REFERENCE (Figure);
2429: Ref_formula = REFERENCE (Isolated_formula);
2430:
2431: EXPORT { Skeleton elements }
2432:
2433: Title,
1.5 cvs 2434: Figure with Figure_caption,
1.1 cvs 2435: Section With Section_title;
2436:
1.18 ! cvs 2437: END { End of the structure schema }</pre>
! 2438: <p>
1.1 cvs 2439: This schema is very complete since it defines both paragraphs and
2440: bibliographic citations. These element types could just as well be defined in
1.18 ! cvs 2441: other structure schemas, as is the case with the <tt>Formula</tt> class. All
1.1 cvs 2442: sorts of other elements can be inserted into an article, since a paragraph can
2443: contain any type of unit. Similarly, figures can be any class of document or
1.18 ! cvs 2444: object that the user chooses.</p>
! 2445: <p>
1.1 cvs 2446: Generally, an article doesn't contain appendices, but it is possible to add
2447: them on explicit request: this is the effect of the question mark before the
1.18 ! cvs 2448: word Appendices.</p>
! 2449: <p>
1.1 cvs 2450: The Figure, Biblio_citation and Note elements are associated elements. Thus,
1.18 ! cvs 2451: they are only used in <tt>REFERENCE</tt> statements.</p>
! 2452: <p>
1.1 cvs 2453: Various types of cross-references can be put in paragraphs. They can also be
2454: placed the objects which are part of the article, since the cross-references
1.18 ! cvs 2455: are defined as units (<tt>UNITS</tt>).</p>
! 2456: <p>
1.1 cvs 2457: There is a single restriction to prevent the creation of Ref_note elements
1.18 ! cvs 2458: within notes.</p>
! 2459: <p>
1.1 cvs 2460: It is worth noting that the S language permits the definition of recursive
2461: structures like sections: a section can contain other sections (which are thus
2462: at the next lower level of the document tree). Paragraphs are also recursive
2463: elements, since a paragraph can contain an enumeration in which each element
1.18 ! cvs 2464: (<tt>Item</tt>) is composed of paragraphs.</p>
! 2465: </div>
1.1 cvs 2466:
1.18 ! cvs 2467: <div class="subsection">
1.1 cvs 2468:
1.18 ! cvs 2469: <h3><a name="sectc332">A class of objects: mathematical formulas</a></h3>
! 2470: <p>
! 2471: The example below defines the <tt>Formula</tt> class which is used in Article
1.1 cvs 2472: documents. This class represents mathematical formulas with a rather simple
2473: structure, but sufficient to produce a correct rendition on the screen or
2474: printer. To support more elaborate operations (formal or numeric
2475: calculations), a finer structure should be defined. This class doesn't use any
1.18 ! cvs 2476: other class and doesn't define any associated elements or units.</p>
! 2477: <pre>STRUCTURE Formula;
1.1 cvs 2478: DEFPRES FormulaP;
2479:
2480: ATTR
2481: String_type = Function_name, Variable_name;
2482:
2483: STRUCT
2484: Formula = Expression;
2485: Expression = LIST OF (Construction);
2486: Construction = CASE OF
2487: TEXT; { Simple character string }
2488: Index = Expression;
2489: Exponent = Expression;
2490: Fraction =
2491: BEGIN
1.6 cvs 2492: Numerator = Expression;
1.1 cvs 2493: Denominator = Expression;
2494: END;
2495: Root =
2496: BEGIN
2497: ? Order = TEXT;
2498: Root_Contents = Expression;
2499: END;
2500: Integral =
2501: BEGIN
2502: Integration_Symbol = SYMBOL;
2503: Lower_Bound = Expression;
2504: Upper_Bound = Expression;
2505: END;
2506: Triple =
2507: BEGIN
2508: Princ_Expression = Expression;
2509: Lower_Expression = Expression;
2510: Upper_Expression = Expression;
2511: END;
2512: Column = LIST [2..*] OF
2513: (Element = Expression);
2514: Parentheses_Block =
2515: BEGIN
2516: Opening = SYMBOL;
2517: Contents = Expression;
2518: Closing = SYMBOL;
2519: END;
2520: END; { End of Choice Constructor }
1.18 ! cvs 2521: END { End of Structure Schema }</pre>
! 2522: <p>
1.1 cvs 2523: This schema defines a single global attribute which allows functions and
2524: variables to be distinguished. In the presentation schema, this attribute can
2525: be used to choose between roman (for functions) and italic characters (for
1.18 ! cvs 2526: variables).</p>
! 2527: <p>
1.1 cvs 2528: A formula's structure is that of a mathematical expression, which is itself a
2529: sequence of mathematical constructions. A mathematical construction can be
2530: either a simple character string, an index, an exponent, a fraction, a root,
2531: etc. Each of these mathematical constructions has a sensible structure which
2532: generally includes one or more expressions, thus making the formula class's
1.18 ! cvs 2533: structure definition recursive.</p>
! 2534: <p>
1.1 cvs 2535: In most cases, the roots which appear in the formulas are square roots and
2536: their order (2) is not specified. This is why the Order component is marked
2537: optional by a question mark. When explicitly requested, it is possible to add
1.18 ! cvs 2538: an order to a root, for example for cube roots (order = 3).</p>
! 2539: <p>
1.1 cvs 2540: An integral is formed by an integration symbol, chosen by the user (simple
2541: integral, double, curvilinear, etc.), and two bounds. A more fine-grained
2542: schema would add components for the integrand and the integration variable.
2543: Similarly, the Block_Parentheses construction leaves the choice of opening and
2544: closing symbols to the user. They can be brackets, braces, parentheses,
1.18 ! cvs 2545: etc.</p>
! 2546: </div>
! 2547: </div>
! 2548: <hr>
! 2549: </div>
1.1 cvs 2550:
1.18 ! cvs 2551: <div class="chapter">
1.1 cvs 2552:
1.18 ! cvs 2553: <h1><a name="sect4">The P Language</a></h1>
1.1 cvs 2554:
1.18 ! cvs 2555: <div class="section">
1.1 cvs 2556:
1.18 ! cvs 2557: <h2><a name="sectb41">Document presentation</a></h2>
! 2558: <p>
1.1 cvs 2559: Because of the model adopted for Thot, the presentation of documents is
2560: clearly separated from their structure and content. After having presented
2561: the logical structure of documents, we now detail the principles implemented
1.18 ! cvs 2562: for their presentation. The concept of <em>presentation</em> encompasses what
1.5 cvs 2563: is often called the page layout, the composition, or the document style. It
1.18 ! cvs 2564: is the set of operations which display the document on the screen or print it
! 2565: on paper. Like logical structure, document presentation is defined
! 2566: generically with the help of a language, called P.</p>
1.1 cvs 2567:
1.18 ! cvs 2568: <div class="subsection">
1.1 cvs 2569:
1.18 ! cvs 2570: <h3><a name="sectc411">Two levels of presentation</a></h3>
! 2571: <p>
1.1 cvs 2572: The link between structure and presentation is clear: the logical organization
2573: of a document is used to carry out its presentation, since the purpose of the
2574: presentation is to make evident the organization of the document. But the
2575: presentation is equally dependent on the device used to render the document.
2576: Certain presentation effects, notably changes of font or character set, cannot
2577: be performed on all printers or on all screens. This is why Thot uses a
2578: two-level approach, where the presentation is first described in abstract
2579: terms, without taking into account each particular device, and then the
1.18 ! cvs 2580: presentation is realized within the constraints of a given device.</p>
! 2581: <p>
1.1 cvs 2582: Thus, presentation is only described as a function of the structure of the
2583: documents and the image that would be produced on an idealized device. For
2584: this reason, presentation descriptions do not refer to any device
1.18 ! cvs 2585: characteristics: they describe <em>abstract presentations</em> which can be
! 2586: concretized on different devices.</p>
! 2587: <p>
! 2588: A presentation description also defines a <em>generic presentation</em>, since
1.1 cvs 2589: it describes the appearance of a class of documents or objects. This generic
2590: presentation must also be applied to document and object instances, each
2591: conforming to its generic logical structure, but with all the allowances that
2592: were called to mind above: missing elements, constructed elements with other
1.18 ! cvs 2593: logical structures, etc.</p>
! 2594: <p>
1.1 cvs 2595: In order to preserve the homogeneity between documents and objects,
2596: presentation is described with a single set of tools which support the layout
2597: of a large document as well as the composition of objects like a graphical
2598: figure or mathematical formula. This unity of presentation description tools
2599: contrasts with the traditional approach, which focuses more on documents than
2600: objects and thus is based on the usual typographic conventions, such as the
2601: placement of margins, indentations, vertical spaces, line lengths,
1.18 ! cvs 2602: justification, font changes, etc.</p>
! 2603: </div>
1.1 cvs 2604:
1.18 ! cvs 2605: <div class="subsection">
1.1 cvs 2606:
1.18 ! cvs 2607: <h3><a name="sectc412">Boxes</a></h3>
! 2608: <p>
1.1 cvs 2609: To assure the homogeneity of tools, all presentation in Thot, for documents as
2610: well as for the objects which they contain, is based on the notion of the
1.18 ! cvs 2611: <em>box</em>, such as was implemented in T<sub><big>E</big></sub>X.</p>
! 2612: <p>
1.1 cvs 2613: Corresponding to each element of the document is a box, which is the
2614: rectangle enclosing the element on the display device (screen or sheet of
1.18 ! cvs 2615: paper); the outline of this rectangle is not visible, except when a <a
! 2616: href="#sectc4230a"><tt>ShowBox</tt> rule</a> applies to the element. The sides
! 2617: of the box are parallel to the sides of the screen or the sheet of paper. By
! 2618: way of example, a box is associated with a character string, a line of text, a
! 2619: page, a paragraph, a title, a mathematical formula, or a table cell.</p>
! 2620: <p>
1.1 cvs 2621: Whatever element it corresponds to, each box possesses four sides and four
1.18 ! cvs 2622: axes, which we designate as follows (<a href="#boxes">see figure</a>):</p>
! 2623: <dl>
! 2624: <dt><tt>Top</tt></dt>
! 2625: <dd>
! 2626: the upper side,
! 2627: </dd>
! 2628: <dt><tt>Bottom</tt></dt>
! 2629: <dd>
! 2630: the lower side,
! 2631: </dd>
! 2632: <dt><tt>Left</tt></dt>
! 2633: <dd>
! 2634: the left side,
! 2635: </dd>
! 2636: <dt><tt>Right</tt></dt>
! 2637: <dd>
! 2638: the right side,
! 2639: </dd>
! 2640: <dt><tt>VMiddle</tt></dt>
! 2641: <dd>
! 2642: the vertical axis passing through the center of the box,
! 2643: </dd>
! 2644: <dt><tt>HMiddle</tt></dt>
! 2645: <dd>
! 2646: the horizontal axis passing through the center of the box,
! 2647: </dd>
! 2648: <dt><tt>VRef</tt></dt>
! 2649: <dd>
! 2650: the vertical reference axis,
! 2651: </dd>
! 2652: <dt><tt>HRef</tt></dt>
! 2653: <dd>
! 2654: the horizontal reference axis.
! 2655: </dd>
! 2656: </dl>
! 2657:
! 2658: <div class="figure">
! 2659: <hr>
! 2660: <pre> Left VRef VMiddle Right
1.1 cvs 2661: : :
2662: Top -----------------------------
2663: | : : |
2664: | : : |
2665: | : : |
2666: | : : |
2667: | : : |
2668: HMiddle ..|...........................|..
2669: | : : |
2670: | : : |
2671: HRef ..|...........................|..
2672: | : : |
2673: | : : |
2674: Bottom -----------------------------
1.18 ! cvs 2675: : :</pre>
! 2676: <p align=center>
! 2677: <em><a name="boxes">The sides and axes of boxes</a><em></em></em></p>
! 2678: <hr>
! 2679: </div>
! 2680: <p>
1.1 cvs 2681: The principal role of boxes is to set the extent and position of the images of
2682: the different elements of a document with respect to each other on the
2683: reproduction device. This is done by defining relations between the boxes of
2684: different elements which give relative extents and positions to these
1.18 ! cvs 2685: boxes.</p>
! 2686: <p>
! 2687: There are three types of boxes:</p>
! 2688: <ul>
! 2689: <li>
! 2690: boxes corresponding to structural elements of the document,
! 2691: <li>
! 2692: presentation boxes,
! 2693: <li>
! 2694: page layout boxes.
! 2695: </ul>
! 2696: <p>
! 2697: <strong>Boxes corresponding to structural elements of the document</strong>
1.1 cvs 2698: are those which linked to each of the elements (base or structured) of the
2699: logical structure of the document. Such a box contains all the contents of
1.18 ! cvs 2700: the element to which it corresponds (there is an exception: see <a
! 2701: href="#sectc4220">rules <tt>VertOverflow</tt> and <tt>HorizOverflow</tt></a>).
! 2702: These boxes form a tree-like structure, identical to that of the structural
! 2703: elements to which they correspond. This tree expresses the inclusion
! 2704: relationships between the boxes: a box includes all the boxes of its subtree.
! 2705: On the other hand, there are no predefined rules for the relative positions of
! 2706: the included boxes. If they are at the same level, they can overlap, be
! 2707: contiguous, or be disjoint. The rules expressed in the generic presentation
! 2708: specify their relative positions.</p>
! 2709: <p>
! 2710: <strong>Presentation boxes</strong> represent elements which are not found in
1.1 cvs 2711: the logical structure of the document but which are added to meet the needs of
2712: presentation. These boxes are linked to the elements of the logical structure
2713: that are best suited to bringing them out. For example, they are used to add
2714: the character string ``Summary:'' before the summary in the presentation of a
2715: report or to represent the fraction bar in a formula, or also to make the
2716: title of a field in a form appear. These elements have no role in the logical
2717: structure of the document: the presence of a Summary element in the document
2718: does not require the creation of another structural object to hold the word
2719: ``Summary''. Similarly, if a Fraction element contains both a Numerator
2720: element and a Denominator element, the fraction bar has no purpose
2721: structurally. On the other hand, these elements of the presentation are
2722: important for the reader of the reproduced document or for the user of an
2723: editor. This is why they must appear in the document's image. It is the
2724: generic presentation which specifies the presentation boxes to add by
2725: indicating their content (a base element for which the value is specified) and
2726: the position that they must take in the tree of boxes. During editing, these
1.18 ! cvs 2727: boxes cannot be modified by the user.</p>
! 2728: <p>
! 2729: <strong>Page layout boxes</strong> are boxes created implicitly by the page
1.1 cvs 2730: layout rules. These rules indicate how the contents of a structured element
2731: must be broken into lines and pages. In contrast to presentation boxes, these
2732: line and page boxes do not depend on the logical structure of the document,
1.18 ! cvs 2733: but rather on the physical constraints of the output devices: character size,
! 2734: height and width of the window on the screen or of the sheet of paper.</p>
! 2735: </div>
1.1 cvs 2736:
1.18 ! cvs 2737: <div class="subsection">
1.1 cvs 2738:
1.18 ! cvs 2739: <h3><a name="sectc413">Views and visibility</a></h3>
! 2740: <p>
1.1 cvs 2741: One of the operations that one might wish to perform on a document is to view
2742: it is different ways. For this reason, it is possible to define several
1.18 ! cvs 2743: <em>views</em> for the same document, or better yet, for all documents of the
1.1 cvs 2744: same class. A view is not a different presentation of the document, but
2745: rather a filter which only allows the display of certain parts of the
2746: document. For example, it might be desirable to see only the titles of
2747: chapters and sections in order to be able to move rapidly through the
2748: document. Such a view could be called a ``table of contents''. It might also
2749: be desirable to see only the mathematical formulas of a document in order to
2750: avoid being distracted by the non-mathematical aspects of the document. A
1.18 ! cvs 2751: ``mathematics'' view could provide this service.</p>
! 2752: <p>
1.1 cvs 2753: Views, like presentation, are based on the generic logical structure. Each
2754: document class, and each generic presentation, can be provided with views
2755: which are particularly useful for that class or presentation. For each view,
1.18 ! cvs 2756: the <em>visibility</em> of elements is defined, indicated whether or not the
1.1 cvs 2757: elements must be presented to the user. The visibility is calculated as a
2758: function of the type of the elements or their hierarchical position in the
2759: structure of the document. Thus, for a table of contents, all the ``Chapter
2760: Title'' and ``Section Title'' elements are made visible. However, the
2761: hierarchical level could be used to make the section titles invisible below a
2762: certain threshold level. By varying this threshold, the granularity of the
2763: view can be varied. In the ``mathematics'' view, only Formula elements would
1.18 ! cvs 2764: be made visible, no matter what their hierarchical level.</p>
! 2765: <p>
1.1 cvs 2766: Because views are especially useful for producing a synthetic image of the
2767: document, it is necessary to adapt the presentation of the elements to the
2768: view in which they appear. For example, it is inappropriate to have a page
2769: break before every chapter title in the table of contents. Thus, generic
2770: presentations take into account the possible views and permit each element
1.18 ! cvs 2771: type's presentation to vary according the view in which its image appears.</p>
! 2772: <p>
! 2773: <a name="views">Views</a> are also used, when editing documents, to display
1.1 cvs 2774: the associated elements. So, in addition to the primary view of the document,
2775: there can be a ``notes'' view and a ``figures'' view which contain,
2776: respectively, the associated elements of the Note and Figure types. In this
2777: way, it is possible to see simultaneously the text which refers to these
2778: elements and the elements themselves, even if they will be separated when
1.18 ! cvs 2779: printed.</p>
! 2780: </div>
1.1 cvs 2781:
1.18 ! cvs 2782: <div class="subsection">
1.1 cvs 2783:
1.18 ! cvs 2784: <h3><a name="sectc414">Pages</a></h3>
! 2785: <p>
1.1 cvs 2786: Presentation schemas can be defined which display the document as a long
2787: scroll, without page breaks. This type of schema is particularly well-suited
2788: to the initial phase of work on a document, where jumps from page to page
2789: would hinder composing and reading the document on a screen. In this case,
2790: the associated elements (such as notes), which are normally displayed in the
2791: page footer, are presented in a separate window. But, once the document is
2792: written, it may be desirable to display the document on the screen in the same
2793: manner in which it will be printed. So, the presentation schema must define
1.18 ! cvs 2794: pages.</p>
! 2795: <p>
1.1 cvs 2796: The P language permits the specification of the dimensions of pages as well as
2797: their composition. It is possible to generate running titles, page numbers,
2798: zones at the bottom of the page for notes, etc. The editor follows this model
2799: and inserts page break marks in the document which are used during printing,
1.18 ! cvs 2800: insuring that the pages on paper are the same as on the screen.</p>
! 2801: <p>
1.1 cvs 2802: Once a document has been edited with a presentation schema defining pages, it
2803: contains page marks. But it is always possible to edit the document using a
2804: schema without pages. In this case, the page marks are simply ignored by the
2805: editor. They are considered again as soon as a schema with pages is used.
1.18 ! cvs 2806: Thus, the user is free to choose between schemas with and without pages.</p>
! 2807: <p>
1.1 cvs 2808: Thot treats the page break, rather than the page itself, as a box. This page
2809: break box contains all the elements of one page's footer, a rule marking the
2810: edge of this page, and all the elements of the next page's header. The
2811: elements of the header and footer can be running titles, page number,
2812: associated elements (notes, for example), etc. All these elements, as well as
2813: their content and graphical appearance, are defined by the generic
1.18 ! cvs 2814: presentation.</p>
! 2815: </div>
1.1 cvs 2816:
1.18 ! cvs 2817: <div class="subsection">
1.1 cvs 2818:
1.18 ! cvs 2819: <h3><a name="sectc415">Numbering</a></h3>
! 2820: <p>
1.1 cvs 2821: Many elements are numbered in documents: pages, chapters, sections, formulas,
2822: theorems, notes, figures, bibliographic references, exercises, examples,
2823: lemmas, etc. Because Thot has a notion of logical structure, all of these
2824: numbers (with the exception of pages) are redundant with information implicit
2825: in the logical structure of the document. Such numbers are simply a way to
2826: make the structure of the document more visible. So, they are part of the
2827: document's presentation and are calculated by the editor from the logical
2828: structure. The structure does not contain numbers as such; it only defines
2829: relative structural positions between elements, which serve as ordering
1.18 ! cvs 2830: relations on these elements.</p>
! 2831: <p>
1.1 cvs 2832: If the structure schema defines the body of a document as a sequence of at
1.18 ! cvs 2833: least two chapters:</p>
! 2834: <pre>Body = LIST [2..*] OF Chapter;</pre>
! 2835: <p>
! 2836: the sequence defined by the list constructor is ordered and each chapter can
! 2837: be assigned a number based on its rank in the Body list. Therefore, all
! 2838: elements contained in lists a the structure of a document can be numbered, but
! 2839: they are not the only ones. The tree structure induced by the aggregate,
! 2840: list, and choice constructors (excluding references) defines a total order on
! 2841: the elements of the document's primary structure. So, it is possible to
! 2842: define a numbering which uses this order, filtering elements according to
! 2843: their type so that only certain element types are taken into account in the
! 2844: numbering. In this way, it possible to number all the theorems and lemmas of
! 2845: a chapter in the same sequence of numbers, even when they are not part of the
! 2846: same list constructor and appear at different levels of the document's tree.
! 2847: By changing the filter, they can be numbered separately: one sequence of
! 2848: numbers for theorems, another for the lemmas.</p>
! 2849: <p>
1.1 cvs 2850: Associated elements pose a special problem, since they are not part of the
2851: document's primary structure, but are attached only by references, which
2852: violate the total order of the document. Then, these associated elements are
2853: frequently numbered, precisely because the number is an effective way to
2854: visualize the reference. In order to resolve this problem, Thot implicitly
2855: defines a list constructor for each type of associated element, gathering
2856: together (and ordering) these elements. Thus, the associated elements can be
1.18 ! cvs 2857: numbered by type.</p>
! 2858: <p>
1.1 cvs 2859: Since they are calculated from the document's logical structure and only for
2860: the needs of the presentation, numbers are presentation elements, described by
2861: presentation boxes, just like the fraction bar or the word ``Summary''.
2862: Nevertheless, numbers differ from these other boxes because their content
2863: varies from instance to instance, even though they are of the same type,
2864: whereas all fraction bars are horizontal lines and the same word ``Summary''
1.18 ! cvs 2865: appears at the head of every document's summary.</p>
! 2866: </div>
1.1 cvs 2867:
1.18 ! cvs 2868: <div class="subsection">
1.1 cvs 2869:
1.18 ! cvs 2870: <h3><a name="sectc416">Presentation parameters</a></h3>
! 2871: <p>
1.1 cvs 2872: The principal parameters which determine document presentation are the
1.18 ! cvs 2873: <em>positions</em> and <em>dimensions</em> of boxes, the <em>font</em>, the
! 2874: <em>style</em>, the <em>size</em>, the <em>underlining</em> and the
! 2875: <em>color</em> of their content. From these parameters, and some others of
1.1 cvs 2876: less importance, it is possible to represent the usual typographic parameters
2877: for the textual parts of the document. These same parameters can be used to
2878: describe the geometry of the non-textual elements, even though they are
1.18 ! cvs 2879: two-dimensional elements unlike the text, which is linear.</p>
! 2880: <p>
1.1 cvs 2881: As we have already seen, the positions of the boxes always respect the rule
2882: of enclosure: a box in the tree encloses all the boxes of the next lower level
2883: which are attached to it. The positional parameters permit the specification
2884: of the position of each box in relation to the enclosing box or to its sibling
2885: boxes (boxes directly attached to the same enclosing box in the tree of
1.18 ! cvs 2886: boxes).</p>
! 2887: <p>
1.1 cvs 2888: The presentation parameters also provide control over the dimensions of the
2889: boxes. The dimensions of a box can depend either on its content or on its
2890: context (its sibling boxes and the enclosing box). Each dimension (height or
1.18 ! cvs 2891: width) can be defined independently of the other.</p>
! 2892: <p>
1.1 cvs 2893: Because of the position and dimension parameters, it is possible to do the
2894: same things that are normally done in typography by changing margins, line
2895: lengths, and vertical or horizontal skips. This approach can also align or
1.18 ! cvs 2896: center elements and groups of elements.</p>
! 2897: <p>
1.1 cvs 2898: In contrast to the position and dimension parameters, the font, style, size,
2899: underlining, and color do not concern the box itself (the rectangle delimiting
2900: the element), but its content. These parameters indicate the typographic
2901: attributes which must be applied to the text contained in the box, and by
1.18 ! cvs 2902: extension, to all base elements.</p>
! 2903: <p>
1.1 cvs 2904: For text, the font parameter is used to change the family of characters
2905: (Times, Helvetica, Courier, etc.); the style is used to obtain italic or
2906: roman, bold or light characters; the size determines the point size of the
2907: characters; underlining defines the type and thickness of the lines drawn
1.18 ! cvs 2908: above, below, or through the characters.</p>
! 2909: <p>
1.1 cvs 2910: For graphics, the line style parameter can be either solid, dotted, or dashed;
2911: the line thickness parameter controls the width of the lines; the fill pattern
1.18 ! cvs 2912: parameter determines how closed geometric figures must be filled.</p>
! 2913: <p>
1.1 cvs 2914: While some of the parameters which determine the appearance of a box's
2915: contents make sense only for one content type (text or graphic), other
2916: parameters apply to all content types: these are the color parameters. These
1.18 ! cvs 2917: indicate the color of lines and the background color.</p>
! 2918: </div>
! 2919: </div>
1.1 cvs 2920:
1.18 ! cvs 2921: <div class="section">
1.1 cvs 2922:
1.18 ! cvs 2923: <h2><a name="sectb42">Presentation description language</a></h2>
! 2924: <p>
1.1 cvs 2925: A generic presentation defines the values of presentation parameters (or the
2926: way to calculate those values) for a generic structure, or more precisely, for
2927: all the element types and all the global and local attributes defined in that
2928: generic structure. This definition of the presentation parameters is made
2929: with the P language. A program written in this language, that is a generic
1.18 ! cvs 2930: presentation expressed in P, is call a <em>presentation schema</em>. This
! 2931: section describes the syntax and semantics of the language, using the same <a
! 2932: href="#sectc321">meta-language</a> as was used for the definition of the S
! 2933: language.</p>
! 2934: <p>
1.1 cvs 2935: Recall that it is possible to write many different presentation schemas for
2936: the same class of documents or objects. This allows users to choose for a
2937: document the graphical appearance which best suits their type of work or
1.18 ! cvs 2938: their personal taste.</p>
1.1 cvs 2939:
1.18 ! cvs 2940: <div class="subsection">
1.1 cvs 2941:
1.18 ! cvs 2942: <h3><a name="sectc421">The organization of a presentation schema</a></h3>
! 2943: <p>
! 2944: A presentation schema begins with the word <tt>PRESENTATION</tt> and ends with
! 2945: the word <tt>END</tt>. The word <tt>PRESENTATION</tt> is followed by the name
1.1 cvs 2946: of the generic structure to which the presentation will be applied. This name
1.18 ! cvs 2947: must be the same as that which follows the keyword <tt>STRUCTURE</tt> in the
! 2948: structure schema associated with the presentation schema.</p>
! 2949: <p>
1.1 cvs 2950: After this declaration of the name of the structure, the following sections
1.18 ! cvs 2951: appear (in order):</p>
! 2952: <ul>
! 2953: <li>
! 2954: Declarations of
! 2955: <ul>
! 2956: <li>
! 2957: all views,
! 2958: <li>
! 2959: printed views,
! 2960: <li>
! 2961: counters,
! 2962: <li>
! 2963: presentation constants,
! 2964: <li>
! 2965: variables,
! 2966: </ul>
! 2967: <li>
! 2968: default presentation rules,
! 2969: <li>
! 2970: presentation box and page layout box definitions,
! 2971: <li>
! 2972: presentation rules for structured elements,
! 2973: <li>
! 2974: presentation rules for attributes,
! 2975: <li>
! 2976: rules for transmitting values to attributes of included documents.
! 2977: </ul>
! 2978: <p>
1.1 cvs 2979: Each of these sections is introduced by a keyword which is followed by a
1.18 ! cvs 2980: sequence of declarations. Every section is optional.</p>
! 2981: <pre> SchemaPres ='PRESENTATION' ElemID ';'
1.1 cvs 2982: [ 'VIEWS' ViewSeq ]
2983: [ 'PRINT' PrintViewSeq ]
2984: [ 'COUNTERS' CounterSeq ]
2985: [ 'CONST' ConstSeq ]
2986: [ 'VAR' VarSeq ]
2987: [ 'DEFAULT' ViewRuleSeq ]
2988: [ 'BOXES' BoxSeq ]
2989: [ 'RULES' PresentSeq ]
2990: [ 'ATTRIBUTES' PresAttrSeq ]
2991: [ 'TRANSMIT' TransmitSeq ]
2992: 'END' .
1.18 ! cvs 2993: ElemID = NAME .</pre>
! 2994: </div>
1.1 cvs 2995:
1.18 ! cvs 2996: <div class="subsection">
1.1 cvs 2997:
1.18 ! cvs 2998: <h3><a name="sectc422">Views</a></h3>
! 2999: <p>
1.1 cvs 3000: Each of the possible views must be declared in the presentation schema. As
1.18 ! cvs 3001: has <a href="#views">already been described</a>, the presentation rules for an
1.1 cvs 3002: element type can vary according to the view in which the element appears. The
3003: name of the view is used to designate the view to which the presentation rules
1.18 ! cvs 3004: apply (see the <a href="#inkeyword"><tt>IN</tt> instruction</a>). The
1.1 cvs 3005: definition of the view's contents are dispersed throughout the presentation
3006: rules attached to the different element types and attributes. The
1.18 ! cvs 3007: <tt>VIEWS</tt> section is simply a sequence of view names separated by commas
! 3008: and terminated by a semi-colon.</p>
! 3009: <p>
1.1 cvs 3010: One of the view names (and only one) can be followed by the keyword
1.18 ! cvs 3011: <tt>EXPORT</tt>. This keyword identifies the view which presents the members
! 3012: of the document class in <a href="#sectc3213">skeleton form</a>. The
! 3013: graphical appearance and the content of this view is defined just as with
! 3014: other views, but it is useless to specify presentation rules concerning this
! 3015: view for the elements which are not loaded in the skeleton form.</p>
! 3016: <p>
1.1 cvs 3017: It is not necessary to declare any views; in this case there is a single
3018: unnamed view. If many views are declared, the first view listed is considered
3019: the principal view. The principal view is the one to which all rules that are
1.18 ! cvs 3020: not preceded by an indication of a view will apply (see the <a
! 3021: href="#inkeyword">instruction <tt>IN</tt></a>).</p>
! 3022: <p>
1.1 cvs 3023: The principal view is the the one which the editor presents on the screen when
3024: the user asks to create or edit a document. Thus, it makes sense to put the
3025: most frequently used view at the head of the list. But if the structure
1.18 ! cvs 3026: schema contains <a href="#sectc3213">skeleton elements</a> and is loaded in
! 3027: its skeleton form, the view whose name is followed by the keyword
! 3028: <tt>EXPORT</tt> will be opened and no other views can be opened.</p>
! 3029: <pre> 'VIEWS' ViewSeq
1.1 cvs 3030: ViewSeq = ViewDeclaration
1.6 cvs 3031: < ',' ViewDeclaration > ';' .
1.1 cvs 3032: ViewDeclaration = ViewID [ 'EXPORT' ] .
1.18 ! cvs 3033: ViewID = NAME .</pre>
! 3034: <blockquote class="example">
! 3035: <p>
! 3036: <strong>Example:</strong></p>
! 3037: <p>
1.3 cvs 3038: When editing a report, it might be useful have views of the table of contents
1.18 ! cvs 3039: and of the mathematical formulas, in addition to the principal view which
! 3040: shows the document in its entirety. To achieve this, a presentation schema
! 3041: for the Report class would have the following <tt>VIEWS</tt> section:</p>
! 3042: <pre>VIEWS
! 3043: Full_text, Table_of_contents, Formulas;</pre>
! 3044: <p>
1.1 cvs 3045: The contents of these views are specified in the presentation rules of the
1.18 ! cvs 3046: schema.</p>
! 3047: </blockquote>
! 3048: </div>
1.1 cvs 3049:
1.18 ! cvs 3050: <div class="subsection">
1.1 cvs 3051:
1.18 ! cvs 3052: <h3><a name="sectc423">Print Views</a></h3>
! 3053: <p>
1.1 cvs 3054: When editing a document, each view is presented in a different window. In
1.18 ! cvs 3055: addition to the views specified by the <tt>VIEWS</tt> instruction, the user
1.1 cvs 3056: can display the associated elements with one window for each type of
1.18 ! cvs 3057: associated element.</p>
! 3058: <p>
1.1 cvs 3059: When printing a document, it is possible to print any number of views, chosen
3060: from among all the views which the editor can display (views in the strict
3061: sense or associated elements). Print views, as well as the order in which
1.18 ! cvs 3062: they must be printed, are indicated by the <tt>PRINT</tt> instruction. It
! 3063: appears after the <tt>VIEWS</tt> instruction and is formed of the keyword
! 3064: <tt>PRINT</tt> followed by the ordered list of print view names. The print
1.1 cvs 3065: view names are separated by commas and followed by a semi-colon. A print view
1.18 ! cvs 3066: name is either a view name declared in the <tt>VIEWS</tt> instruction or the
1.1 cvs 3067: name of an associated element type (with an ``s'' added to the end). The
1.18 ! cvs 3068: associated element must have been declared in the <tt>ASSOC</tt> section of
! 3069: the structure schema.</p>
! 3070: <pre> 'PRINT' PrintViewSeq
1.1 cvs 3071: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.18 ! cvs 3072: PrintView = ViewID / ElemID .</pre>
! 3073: <p>
! 3074: If the <tt>PRINT</tt> instruction is absent, the printing program will print
! 3075: only the principal view (the first view specified by the <tt>VIEWS</tt>
! 3076: instruction or the single, unnamed view when there is no <tt>VIEWS</tt>
! 3077: instruction).</p>
! 3078: <blockquote class="example">
! 3079: <p>
! 3080: <strong>Example:</strong></p>
! 3081: <p>
1.3 cvs 3082: Consider a Report presentation using the view declarations from the preceding
3083: example. Suppose we want to print the full text and table of contents views,
3084: but not the Formulas view, which is only useful when editing. In addition,
3085: suppose that we also want to print the bibliographic citations, which are
1.18 ! cvs 3086: associated elements (of type <tt>Citation</tt>). A sensible printing order
1.3 cvs 3087: would be to print the full text then the bibliography and finally the table of
3088: contents. To obtain this result when printing, the presentation schema would
1.18 ! cvs 3089: say:</p>
! 3090: <pre>PRINT
! 3091: Full_text, Citations, Table_of_contents;</pre>
! 3092: </blockquote>
! 3093: </div>
! 3094:
! 3095: <div class="subsection">
! 3096:
! 3097: <h3><a name="sectc424">Counters</a></h3>
! 3098: <p>
! 3099: A presentation has a <em>counter</em> for each type of number in the
1.1 cvs 3100: presentation. All counters, and therefore all types of numbers, used in the
1.18 ! cvs 3101: schema must be declared after the <tt>COUNTERS</tt> keyword.</p>
! 3102: <p>
1.1 cvs 3103: Each counter declaration is composed of a name identifying the counter
3104: followed by a colon and the counting function to be applied to the counter.
1.18 ! cvs 3105: The counter declaration ends with a semi-colon.</p>
! 3106: <p>
1.1 cvs 3107: The counting function indicates how the counter values will be calculated.
1.16 cvs 3108: Three types of counting functions are available. The first type is used to
3109: count the elements of a list or aggregate: it assigns to the counter the rank
1.18 ! cvs 3110: of the element in the list or aggregate. More precisely, the function</p>
! 3111: <pre>RANK OF ElemID [ LevelAsc ] [ INIT AttrID ]
! 3112: [ 'REINIT' AttrID ]</pre>
! 3113: <p>
! 3114: indicates that when an element creates, by a creation rule (see the <a
! 3115: href="#sectc4232"><tt>Create</tt> instructions</a>), a presentation box
1.5 cvs 3116: containing the counter value, this value is the rank of the creating element,
1.18 ! cvs 3117: if it is of type <tt>ElemID</tt>, otherwise the rank of the first element of
! 3118: type <tt>ElemID</tt> which encloses the creating element in the logical
! 3119: structure of the document.</p>
! 3120: <p>
1.1 cvs 3121: The type name can be preceded by a star in the special case where the
1.18 ! cvs 3122: structure schema defines an element of whose <tt>ElemID</tt> is the same as
! 3123: that of an <a href="#sectd3284">inclusion</a> without expansion or with
! 3124: partial expansion. To resolve this ambiguity, the <tt>ElemID</tt> alone
! 3125: refers to the type defined in the structure schema while the <tt>ElemID</tt>
! 3126: preceded by a star refers to the included type.</p>
! 3127: <p>
! 3128: The type name <tt>ElemID</tt> can be followed by an integer. That number
1.1 cvs 3129: represents the relative level, among the ancestors of the creating element, of
1.18 ! cvs 3130: the element whose rank is asked. If that relative level <i>n</i> is unsigned,
! 3131: the <i>n</i><sup>th</sup> element of type <tt>ElemID</tt> encountered when
1.1 cvs 3132: travelling the logical structure from the root to the creating element is
1.16 cvs 3133: taken into account. If the relative level is negative, the logical structure
3134: is travelled in the other direction, from the creating element to the
1.18 ! cvs 3135: root.</p>
! 3136: <p>
! 3137: The function can end with the keyword <tt>INIT</tt> followed by the name of a
1.1 cvs 3138: numeric attribute (and only a numeric attribute). Then, the rank of the first
3139: element of the list or aggregate is considered to be the value of this
3140: attribute, rather than the default value of 1, and the rank of the other
3141: elements is shifted accordingly. The attribute which determines the initial
1.18 ! cvs 3142: value is searched on the element itself and on its ancestors.</p>
! 3143: <p>
! 3144: The function can end with the keyword <tt>REINIT</tt> followed by the name of
1.1 cvs 3145: a numeric attribute (and only a numeric attribute). Then, if an element to be
3146: counted has this attribute, the counter value for this element is the
3147: attribute value and the following elements are numbered starting from this
1.18 ! cvs 3148: value.</p>
! 3149: <p>
! 3150: When the <tt>RANK</tt> function is written</p>
! 3151: <pre>RANK OF Page [ ViewID ] [ INIT AttrID ]</pre>
! 3152: <p>
! 3153: (<tt>Page</tt>is a keyword of the P language), the counter takes as its value
1.5 cvs 3154: the number of the page on which the element which creates the presentation box
3155: containing the number appears. This is done as if the pages of the document
3156: form a list for each view. The counter only takes into account the pages of
3157: the relevant view, that is the view displaying the presentation box whose
1.18 ! cvs 3158: contents take the value of the number. However, if the keyword <tt>Page</tt>
1.5 cvs 3159: is followed by the name of a view (between parentheses), it is the pages of
3160: that view that are taken into account. As in the preceding form, the
1.18 ! cvs 3161: <tt>RANK</tt> function applied to pages can end with the <tt>INIT</tt> keyword
1.5 cvs 3162: followed by the name of a numeric attribute which sets the value of the first
3163: page's number. This attribute must be a local attribute of the document
1.18 ! cvs 3164: itself, and not of one of its components.</p>
! 3165: <p>
1.1 cvs 3166: The second counting function is used to count the occurrences of a certain
1.18 ! cvs 3167: element type in a specified context. The instruction</p>
! 3168: <pre>SET n ON Type1 ADD m ON Type2 [ INIT AttrID ]</pre>
! 3169: <p>
1.5 cvs 3170: says that when the document is traversed from beginning to end (in the order
1.18 ! cvs 3171: induced by the logical structure), the counter is assigned the value
! 3172: <tt>n</tt> each time an element of type <tt>Type1</tt> is encountered, no
! 3173: matter what the current value of the counter, and the value <tt>m</tt> is
! 3174: added to the current value of the counter each time an element of type
! 3175: <tt>Type2</tt> is encountered.</p>
! 3176: <p>
! 3177: As with the <tt>RANK</tt> function, the type names can be preceded by a star
! 3178: to resolve the ambiguity of included elements.</p>
! 3179: <p>
! 3180: If the function ends with the keyword <tt>INIT</tt> followed by the name of an
1.1 cvs 3181: attribute and if the document possesses this attribute, the value of this
1.18 ! cvs 3182: attribute is used in place of <tt>n</tt>. The attribute must be numeric. It
! 3183: is searched on the element itself and on its ancestors.</p>
! 3184: <p>
! 3185: This function can also be used with the <tt>Page</tt> keyword in the place of
! 3186: <tt>Type1</tt> or <tt>Type2</tt>. In the first case, the counter is
! 3187: reinitialized on each page with the value <tt>n</tt>, while in the second
! 3188: case, it is incremented by <tt>m</tt> on each page. As with the preceding
! 3189: counting function, the word <tt>Page</tt> can be followed by a name between
1.1 cvs 3190: parentheses. In this case, the name specifies a view whose pages are taken
1.18 ! cvs 3191: into account.</p>
! 3192: <p>
! 3193: The definition of a counter can contain several <tt>SET</tt> functions and
! 3194: several <tt>ADD</tt> functions, each with a different value. The total number
! 3195: of counting functions must not be greater than 6.</p>
! 3196: <p>
1.1 cvs 3197: The third counting function is used to count the elements of a certain type
1.16 cvs 3198: encountered when travelling from the creating element to the root of the
3199: logical structure. The creating element is included if it is of that type.
1.18 ! cvs 3200: That function is written</p>
! 3201: <pre>RLEVEL OF Type</pre>
! 3202: <p>
! 3203: where <tt>Type</tt> represents the type of the elements to be counted.</p>
! 3204: <p>
! 3205: The formal definition of counter declarations is:</p>
! 3206: <pre> 'COUNTERS' CounterSeq
1.1 cvs 3207: CounterSeq = Counter < Counter > .
3208: Counter = CounterID ':' CounterFunc ';' .
3209: CounterID = NAME .
3210: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
1.16 cvs 3211: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.1 cvs 3212: SetFunction < SetFunction >
1.16 cvs 3213: AddFunction < AddFunction >
3214: [ 'INIT' AttrID ] /
3215: 'RLEVEL' 'OF' ElemID .
1.1 cvs 3216: SLevelAsc = [ '-' ] LevelAsc .
3217: LevelAsc = NUMBER .
3218: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
3219: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
3220: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 3221: [ '*' ] ElemID .
1.18 ! cvs 3222: CounterValue = NUMBER .</pre>
! 3223: <blockquote class="example">
! 3224: <p>
! 3225: <strong>Example:</strong></p>
! 3226: <p>
1.3 cvs 3227: If the body of a chapter is defined as a sequence of sections in the structure
1.18 ! cvs 3228: schema:</p>
! 3229: <pre>Chapter_body = LIST OF (Section =
1.1 cvs 3230: BEGIN
3231: Section_Title = Text;
3232: Section_Body = Paragraphs;
3233: END
1.18 ! cvs 3234: );</pre>
! 3235: <p>
! 3236: the section counter is declared:</p>
! 3237: <pre>SectionCtr : RANK OF Section;</pre>
! 3238: <p>
! 3239: and the display of the section number before the section title is obtained by
! 3240: a <a href="#sectc4232"><tt>CreateBefore</tt> rule</a> attached the
! 3241: <tt>Section_Title</tt> type, which creates a presentation box whose content is
! 3242: the value of the <tt>SectionCtr</tt> counter (see the <a
! 3243: href="#sectc4231"><tt>Content</tt> instruction</a>).</p>
! 3244: <p>
1.1 cvs 3245: In order to number the formulas separately within each chapter, the formula
1.18 ! cvs 3246: counter is declared:</p>
! 3247: <pre>FormulaCtr : SET 0 ON Chapter ADD 1 ON Formula;</pre>
! 3248: <p>
1.4 cvs 3249: and the display of the formula number in the right margin, alongside each
1.18 ! cvs 3250: formula, is obtained by a <tt>CreateAfter</tt> instruction attached to the
! 3251: <tt>Formula</tt> type, which creates a presentation box whose content is the
! 3252: value of the <tt>FormulaCtr</tt> counter.</p>
! 3253: <p>
1.1 cvs 3254: To number the page chapter by chapter, with the first page of each chapter
1.18 ! cvs 3255: having the number 1, the counter definition would be</p>
! 3256: <pre>ChapterPageCtr : SET 0 ON Chapter ADD 1 ON Page;</pre>
! 3257: <p>
! 3258: If there is also a chapter counter</p>
! 3259: <pre>ChapterCtr : RANK OF Chapter;</pre>
! 3260: <p>
! 3261: the <a href="#sectc4231">content</a> of a presentation box created at the top
! 3262: of each page could be defined as:</p>
! 3263: <pre>Content : (VALUE(ChapterCtr, URoman) TEXT '-'
! 3264: VALUE(ChapterPageCtr, Arabic));</pre>
! 3265: <p>
1.5 cvs 3266: Thus, the presentation box contains the number of the chapter in upper-case
1.18 ! cvs 3267: roman numerals followed by a hyphen and the number of the page within the
! 3268: chapter in arabic numerals.</p>
! 3269: </blockquote>
! 3270: <blockquote class="example">
! 3271: <p>
! 3272: <strong>Example:</strong></p>
! 3273: <p>
1.3 cvs 3274: To count tables and figures together in a document of the chapter type, a
1.18 ! cvs 3275: counter could be defined using:</p>
! 3276: <pre>CommonCtr : SET 0 ON Chapter ADD 1 ON Table
! 3277: ADD 1 ON Figure;</pre>
! 3278: </blockquote>
! 3279: </div>
1.1 cvs 3280:
1.18 ! cvs 3281: <div class="subsection">
1.1 cvs 3282:
1.18 ! cvs 3283: <h3><a name="sectc425">Presentation constants</a></h3>
! 3284: <p>
1.1 cvs 3285: Presentation constants are used in the definition of the content of
1.18 ! cvs 3286: presentation boxes. This content is used in <a href="#sectc426">variable
! 3287: definitions</a> and in the <a href="#sectc4231"><tt>Content</tt> rule</a>. The
1.1 cvs 3288: only presentation constants which can be used are character strings,
1.2 cvs 3289: mathematical symbols, graphical elements, and pictures, that is to say, base
1.18 ! cvs 3290: elements.</p>
! 3291: <p>
1.1 cvs 3292: Constants can be defined directly in the variables or presentation boxes
1.18 ! cvs 3293: (<tt>Content</tt> rule) which use them. But it is only necessary them to
1.1 cvs 3294: declare once, in the constant declaration section, even though they are used
3295: in many variables or boxes. Thus, each declared constant has a name, which
3296: allows it to be designated whenever it is used, a type (one of the four base
3297: types) and a value (a character string or a single character for mathematical
1.18 ! cvs 3298: symbols and graphical elements).</p>
! 3299: <p>
! 3300: The constant declarations appear after the keyword <tt>CONST</tt>. Each
1.1 cvs 3301: declaration is composed of the name of the constant, an equals sign, a keyword
1.18 ! cvs 3302: representing its type (<tt>Text</tt>, <tt>Symbol</tt>, <tt>Graphics</tt> or
! 3303: <tt>Picture</tt>) and the string representing its value. A semi-colon
! 3304: terminates each declaration.</p>
! 3305: <p>
! 3306: In the case of a character string, the keyword <tt>Text</tt> can be followed
! 3307: by the name of an alphabet (for example, <tt>Greek</tt> or <tt>Latin</tt>) in
1.1 cvs 3308: which the constant's text should be expressed. If the alphabet name is
3309: absent, the Latin alphabet is used. When the alphabet name is present, only
3310: the first letter of the alphabet name is interpreted. Thus, the words
1.18 ! cvs 3311: <tt>Greek</tt> and <tt>Grec</tt> designate the same alphabet. In current
! 3312: versions of Thot, only the Greek and Latin alphabets are available.</p>
! 3313: <pre> 'CONST' ConstSeq
1.1 cvs 3314: ConstSeq = Const < Const > .
3315: Const = ConstID '=' ConstType ConstValue ';' .
3316: ConstID = NAME .
3317: ConstType ='Text' [ Alphabet ] / 'Symbol' /
3318: 'Graphics' / 'Picture' .
3319: ConstValue = STRING .
1.18 ! cvs 3320: Alphabet = NAME .</pre>
! 3321: <p>
1.5 cvs 3322: For character strings in the Latin alphabet (ISO Latin-1 character set),
1.1 cvs 3323: characters having codes higher than 127 (decimal) are represented by their
1.18 ! cvs 3324: code in octal.</p>
! 3325: <p>
1.1 cvs 3326: In the case of a symbol or graphical element, the value only contains a single
3327: character, between apostrophes, which indicates the form of the element which
3328: must be drawn in the box whose content is the constant. The symbol or
3329: graphical element takes the dimensions of the box, which are determined by the
1.18 ! cvs 3330: <tt>Height</tt> and <tt>Width</tt> rules. See <a href="#sectb72">table of
! 3331: codes</a> for the symbols and graphical elements.</p>
! 3332: <blockquote class="example">
! 3333: <p>
! 3334: <strong>Example:</strong></p>
! 3335: <p>
1.3 cvs 3336: The constants ``Summary:'' and fraction bar, which were described earlier, are
1.18 ! cvs 3337: declared:</p>
! 3338: <pre>CONST
1.1 cvs 3339: SummaryConst = Text 'Summary:';
1.18 ! cvs 3340: Bar = Graphics 'h';</pre>
! 3341: </blockquote>
! 3342: </div>
1.1 cvs 3343:
1.18 ! cvs 3344: <div class="subsection">
1.1 cvs 3345:
1.18 ! cvs 3346: <h3><a name="sectc426">Variables</a></h3>
! 3347: <p>
1.1 cvs 3348: Variables permit the definition of computed content for presentation boxes. A
1.18 ! cvs 3349: variable is associated with a presentation box by a <tt>Content</tt> rule; but
! 3350: before being used in a <tt>Content</tt> rule, a variable can be defined in the
! 3351: <tt>VAR</tt> section. It is also possible to define a variable at the time of
! 3352: its use in a <tt>Content</tt> rule, as can be done with a constant.</p>
! 3353: <p>
1.1 cvs 3354: A variable has a name and a value which is a character string resulting from
3355: the concatenation of the values of a sequence of functions. Each variable
3356: declaration is composed of the variable name followed by a colon and the
3357: sequence of functions which produces its value, separated by spaces. Each
1.18 ! cvs 3358: declaration is terminated by a semi-colon.</p>
! 3359: <pre> 'VAR' VarSeq
1.1 cvs 3360: VarSeq = Variable < Variable > .
3361: Variable = VarID ':' FunctionSeq ';' .
3362: VarID = NAME .
1.18 ! cvs 3363: FunctionSeq = Function < Function > .</pre>
! 3364: <p>
1.1 cvs 3365: Several functions are available. The first two return, in the form of a
1.18 ! cvs 3366: character string, the current date. <tt>DATE</tt> returns the date in
! 3367: English, while <tt>FDATE</tt> returns the date in french.</p>
! 3368: <p>
! 3369: Two other functions, <tt>DocName</tt> and <tt>DirName</tt>, return the
! 3370: document name and the directory where the document is stored.</p>
! 3371: <p>
! 3372: Function <tt>ElemName</tt> returns the type of the element which created the
! 3373: presentation box whose contents are the variable.</p>
! 3374: <p>
1.1 cvs 3375: Another function simply returns the value of a presentation constant. For any
1.18 ! cvs 3376: constant declared in the <tt>CONST</tt> section, it is sufficient to give the
1.1 cvs 3377: name of the constant. Otherwise, the type and value of the constant must be
1.18 ! cvs 3378: given, using the same form as in a <a href="#sectc425">constant
! 3379: declaration</a>. If the constant is not of type text, (types <tt>Symbol</tt>,
! 3380: <tt>Graphics</tt> or <tt>Picture</tt>), it must be alone in the variable
! 3381: definition; only constants of type <tt>Text</tt> can be mixed with other
! 3382: functions.</p>
! 3383: <p>
1.1 cvs 3384: It is also possible to obtain the value of an attribute, simply by mentioning
3385: the attribute's name. The value of this function is the value of the
3386: attribute for the element which created the presentation box whose contents
3387: are the variable. If the creating element does not have the indicated
3388: attribute, the value is an empty string. In the case of a numeric attribute,
3389: the attribute is translated into a decimal number in arabic numerals. If
1.18 ! cvs 3390: another form is desired, the <tt>VALUE</tt> function must be used.</p>
! 3391: <p>
1.1 cvs 3392: The last available function returns, as a character string, the value of a
3393: counter, an attribute or a page number. This value can be presented in
1.18 ! cvs 3394: different styles. The keyword <tt>VALUE</tt> is followed (between
1.1 cvs 3395: parentheses) by the name of the counter, the name of the attribute, or the
1.18 ! cvs 3396: keyword <tt>PageNumber</tt> and the desired style, the two parameters being
1.1 cvs 3397: separated by a comma. The style is a keyword which indicates whether the
1.18 ! cvs 3398: value should be presented in arabic numerals (<tt>Arabic</tt>), lower-case
! 3399: roman numerals (<tt>LRoman</tt>), or upper-case roman numerals
! 3400: (<tt>URoman</tt>), or by an upper-case letter (<tt>Uppercase</tt>) or
! 3401: lower-case letter (<tt>Lowercase</tt>).</p>
! 3402: <p>
! 3403: For a page counter, the keyword <tt>PageNumber</tt> can be followed, between
1.1 cvs 3404: parentheses, by the name of the view from which to obtain the page number. By
1.18 ! cvs 3405: default, the first view declared in the <tt>VIEWS</tt> section is used. The
1.1 cvs 3406: value obtained is the number of the page on which is found the element that is
1.18 ! cvs 3407: using the variable in a <tt>Content</tt> rule.</p>
! 3408: <p>
1.1 cvs 3409: For an ordinary counter, the name of the counter can be preceded by the
1.18 ! cvs 3410: keyword <tt>MaxRangeVal</tt> or <tt>MinRangeVal</tt>. These keywords mean
1.1 cvs 3411: that the value returned by the function is the maximum (minimum resp.) value
3412: taken by the counter in the whole document, not the value for the element
1.18 ! cvs 3413: concerned by the function.</p>
! 3414: <pre> Function = 'DATE' / 'FDATE' /
1.1 cvs 3415: 'DocName' / 'DirName' /
3416: 'ElemName' / 'AttributeName' /
3417: ConstID / ConstType ConstValue /
3418: AttrID /
3419: 'VALUE' '(' PageAttrCtr ','
3420: CounterStyle ')' .
1.6 cvs 3421: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
1.1 cvs 3422: [ MinMax ] CounterID / AttrID .
3423: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
3424: 'Uppercase' / 'Lowercase' .
1.18 ! cvs 3425: MinMax = 'MaxRangeVal' / 'MinRangeVal' .</pre>
! 3426: <blockquote class="example">
! 3427: <p>
! 3428: <strong>Example:</strong></p>
! 3429: <p>
! 3430: To make today's date appear at the top of the first page of a report, a <a
! 3431: href="#sectc4232"><tt>CREATE</tt> rule</a> associated with the Report_Title
1.3 cvs 3432: element type generates a presentation box whose content (specified by the
1.18 ! cvs 3433: <tt>Content</tt> rule of that presentation box) is the variable:</p>
! 3434: <pre>VAR
! 3435: Todays_date : TEXT 'Version of ' DATE;</pre>
! 3436: <p>
1.1 cvs 3437: To produce, before each section title, the chapter number (in upper-case roman
3438: numerals) followed by the section number (in arabic numerals), two counters
1.18 ! cvs 3439: must be defined:</p>
! 3440: <pre>COUNTERS
1.1 cvs 3441: ChapterCtr : RANK OF Chapter;
1.18 ! cvs 3442: SectionCtr : RANK OF Section;</pre>
! 3443: <p>
1.4 cvs 3444: and the Section_Title element must create a presentation box whose content is
1.18 ! cvs 3445: the variable</p>
! 3446: <pre>VAR
1.1 cvs 3447: SectionNum : VALUE (ChapterCtr, URoman) TEXT '-'
1.18 ! cvs 3448: VALUE (SectionCtr, Arabic);</pre>
! 3449: <p>
1.1 cvs 3450: In order to make the page number on which each section begins appear in the
3451: table of contents view next to the section title, each Section_Title element
3452: must create a presentation box, visible only in the table of contents view,
1.18 ! cvs 3453: whose content is the variable:</p>
! 3454: <pre>VAR
1.1 cvs 3455: TitlePageNume :
1.18 ! cvs 3456: VALUE (PageNumber(Full_text), Arabic);</pre>
! 3457: </blockquote>
! 3458: </div>
1.1 cvs 3459:
1.18 ! cvs 3460: <div class="subsection">
1.1 cvs 3461:
1.18 ! cvs 3462: <h3><a name="sectc427">Default presentation rules</a></h3>
! 3463: <p>
1.1 cvs 3464: In order to avoid having to specify, for each element type defined in the
3465: structure schema, values for every one of the numerous presentation
3466: parameters, the presentation schema allows the definition of a set of default
3467: presentation rules. These rules apply to all the boxes of the elements
3468: defined in the structure schema and to the presentation boxes and page layout
3469: boxes defined in the presentation schema. Only rules which differ from these
1.18 ! cvs 3470: default need to be specified in other sections of the presentation schema.</p>
! 3471: <p>
1.1 cvs 3472: For the primary view, the default rules can define every presentation
1.18 ! cvs 3473: parameter, but not the <a href="#presfunct">presentation functions</a> or the
! 3474: <a href="#sectc4223">linebreaking conditions</a> (the <tt>NoBreak1</tt>,
! 3475: <tt>NoBreak2</tt>, and <tt>Gather</tt> rules).</p>
! 3476: <p>
1.1 cvs 3477: In a presentation schema, the default presentation rules section is optional;
1.18 ! cvs 3478: in this case, the <tt>DEFAULT</tt> keyword is also absent and the following
! 3479: rules are considered to be the default rules:</p>
! 3480: <pre> Visibility: Enclosing =;
1.6 cvs 3481: VertRef: * . Left;
3482: HorizRef: Enclosed . HRef;
3483: Height: Enclosed . Height;
3484: Width: Enclosed . Width;
3485: VertPos: Top = Previous . Bottom;
3486: HorizPos: Left = Enclosing . Left;
3487: VertOverflow: No;
1.1 cvs 3488: HorizOverflow: No;
1.6 cvs 3489: Size: Enclosing =;
3490: Style: Enclosing =;
3491: Font: Enclosing =;
3492: Underline: Enclosing =;
3493: Thickness: Enclosing =;
3494: Indent: Enclosing =;
3495: LineSpacing: Enclosing =;
3496: Adjust: Enclosing =;
3497: Justify: Enclosing =;
3498: Hyphenate: Enclosing =;
3499: PageBreak: Yes;
3500: LineBreak: Yes;
3501: InLine: Yes;
3502: Depth: 0;
3503: LineStyle: Enclosing =;
3504: LineWeight: Enclosing =;
3505: FillPattern: Enclosing =;
3506: Background: Enclosing =;
1.18 ! cvs 3507: Foreground: Enclosing =;</pre>
! 3508: <p>
1.1 cvs 3509: If other values are desired for the default rules, they must be defined
3510: explicitly in the default rules section. In fact, it is only necessary to
3511: define those default rules which differ from the ones above, since the rules
1.18 ! cvs 3512: above will be used whenever a rule is not explicitly named.</p>
! 3513: <p>
1.1 cvs 3514: Default rules for views other than the primary view can also be specified.
3515: Otherwise, the default rules for the primary views are applied to the other
1.18 ! cvs 3516: views.</p>
! 3517: <p>
! 3518: Default rules are expressed in the same way as <a href="#sectc4215">explicit
! 3519: rules for document elements</a>.</p>
! 3520: </div>
1.1 cvs 3521:
1.18 ! cvs 3522: <div class="subsection">
1.1 cvs 3523:
1.18 ! cvs 3524: <h3><a name="sectc428">Presentation and page layout boxes</a></h3>
! 3525: <p>
1.1 cvs 3526: The presentation process uses elements which are not part of the logical
3527: structure of the document, such as pages (which are the page layout boxes) or
3528: alternatively, rules, numbers, or words introducing certain parts of the
3529: document, such as ``Summary'', ``Appendices'', ``Bibliography'', etc. (which
1.18 ! cvs 3530: are presentation boxes).</p>
! 3531: <p>
! 3532: After the word <tt>BOXES</tt>, each presentation or page layout box is defined
1.1 cvs 3533: by its name and a sequence of presentation rules which indicate how they must
3534: be displayed. These rules are the same as those which define the boxes
3535: associated with element of the logical structure of the document, with a
1.18 ! cvs 3536: single exception, the <a href="#sectc4231"><tt>Content</tt> rule</a> which is
1.1 cvs 3537: used only to specify the content of presentation boxes. The content of boxes
3538: associated with elements of the document structure is defined in each document
3539: or object and thus is not specified in the presentation schema, which applies
1.18 ! cvs 3540: to all documents or objects of a class.</p>
! 3541: <p>
1.1 cvs 3542: Among the rules which define a presentation box, certain ones can refer to
3543: another presentation box (for example, in their positional rules). If the
3544: designated box is defined after the box which designates it, a
1.18 ! cvs 3545: <tt>FORWARD</tt> instruction followed by the name of the designated box must
! 3546: appear before the designation.</p>
! 3547: <pre> 'BOXES' BoxSeq
1.1 cvs 3548: BoxSeq = Box < Box > .
3549: Box ='FORWARD' BoxID ';' /
3550: BoxID ':' ViewRuleSeq .
1.18 ! cvs 3551: BoxID = NAME .</pre>
! 3552: </div>
1.1 cvs 3553:
1.18 ! cvs 3554: <div class="subsection">
1.1 cvs 3555:
1.18 ! cvs 3556: <h3><a name="sectc429">Presentation of structured elements</a></h3>
! 3557: <p>
! 3558: After the words <tt>RULES</tt>, the presentation schema gives the presentation
1.1 cvs 3559: rules that apply to the elements whose types are defined in the structure
1.18 ! cvs 3560: schema. Only those rules which differ from the <a
! 3561: href="#sectc427">default</a> must be specified in the <tt>RULES</tt>
! 3562: section.</p>
! 3563: <p>
1.1 cvs 3564: The rule definitions for each element type are composed of the name of the
3565: element type (as specified in the structure schema) followed by a colon and
1.18 ! cvs 3566: the set of rules specific to that type.</p>
! 3567: <p>
1.1 cvs 3568: The type name can be preceded by a star in the special case where the
1.18 ! cvs 3569: structure schema defines an <a href="#sectd3284">inclusion</a> without
1.1 cvs 3570: expansion (or with partial expansion) of a type with the same name as an
1.18 ! cvs 3571: element of defined in the structure schema.</p>
! 3572: <p>
! 3573: In the case where the element is a <a href="#sectd3285">mark pair</a>, but
! 3574: only in this case, the type name can be preceded by the keywords
! 3575: <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
! 3576: that follow apply to the first or second mark of the pair.</p>
! 3577: <pre> 'RULES' PresentSeq
1.1 cvs 3578: PresentSeq = Present < Present > .
1.6 cvs 3579: Present = [ '*' ] [ FirstSec ] ElemID ':'
3580: ViewRuleSeq .
1.18 ! cvs 3581: FirstSec = 'First' / 'Second' .</pre>
! 3582: <p>
1.1 cvs 3583: A presentation schema can define presentation rules for base elements, which
3584: are defined implicitly in the structure schemas. In the English version of
3585: the presentation schema compiler, the base type names are the same as in the S
1.18 ! cvs 3586: language, but they are terminated by the <tt>_UNIT</tt> suffix:
! 3587: <tt>TEXT_UNIT</tt>, <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>,
! 3588: <tt>GRAPHICS_UNIT</tt>. The base type names are written in upper-case
! 3589: letters.</p>
! 3590: </div>
! 3591:
! 3592: <div class="subsection">
! 3593:
! 3594: <h3><a name="sectc4210">Logical attribute presentation</a></h3>
! 3595: <p>
! 3596: After the keyword <tt>ATTRIBUTES</tt>, all attributes which are to have some
1.1 cvs 3597: effect on the presentation of the element to which they are attached must be
3598: mentioned, along with the corresponding presentation rules. This is true for
3599: both global attributes (which can be attached to all element types) and local
1.18 ! cvs 3600: attributes (which can only be attached to certain element types).</p>
! 3601: <p>
1.1 cvs 3602: Also mentioned in this section are attributes which imply an effect on
3603: elements in the subtree of the element to which they are attached. The
3604: presentation of these descendants can be modified as a function of the value
3605: of the attribute which they inherit, just as if it was attached to them
1.18 ! cvs 3606: directly.</p>
! 3607: <p>
1.1 cvs 3608: The specification for each attribute includes the attribute's name, followed
3609: by an optional value specification and, after a colon, a set of rules. The
1.18 ! cvs 3610: set of rules must contain at least one rule.</p>
! 3611: <p>
1.1 cvs 3612: When there is no value specification, the rules are applied to all elements
3613: which carry the attribute, no matter what their value. When the rules must
3614: only apply when the attribute has certain values, these values must be
1.18 ! cvs 3615: specified. Thus, the same attribute can appear in the <tt>ATTRIBUTES</tt>
1.1 cvs 3616: section several times, with each appearance having a different value
3617: specification. However, reference attributes never have a value specification
1.18 ! cvs 3618: and, as a result, can only appear once in the <tt>ATTRIBUTES</tt> section.</p>
! 3619: <p>
1.1 cvs 3620: To specify that the presentation rules apply to some of the descendants of the
3621: element having the attribute, the name of the affected element type is given,
3622: between parentheses, after the attribute name. This way, the presentation
3623: rules for the attribute will be applied to the element having the attribute,
3624: if it is of the given type, and to all of its descendants of the given type.
1.18 ! cvs 3625: In the case where this type is a <a href="#sectd3285">mark pair</a>, but only
! 3626: in this case, the type name can be preceded by the keywords <tt>First</tt> or
! 3627: <tt>Second</tt>. These keywords indicate whether the rules that follow apply
1.1 cvs 3628: to the first or second mark of the pair. If the rule must apply to several
3629: different element types, the specification must be repeated for each element
1.18 ! cvs 3630: type.</p>
! 3631: <p>
1.1 cvs 3632: The specification of values for which the presentation rules will be applied
1.18 ! cvs 3633: varies according to the type of the attribute:</p>
! 3634: <dl>
! 3635: <dt>numeric attribute</dt>
! 3636: <dd>
! 3637: If the rules are to apply for one value of the attribute, then the attribute
! 3638: name is followed by an equals sign and this value. If the rules are to apply
! 3639: for all values less than (or greater than) a threshold value, non-inclusive,
! 3640: the attribute name followed by a '<' sign (or a '>' sign, respectively) and
! 3641: the threshold value. If the rules must apply to a range of values, the
! 3642: attribute name is followed by the word '<tt>IN</tt>' and the two bounds of the
! 3643: range, enclosed in brackets and separated by two periods ('<tt>..</tt>'). In
! 3644: the case of ranges, the values of the bounds are included in the range.
! 3645: <p>
1.1 cvs 3646: The threshold value in the comparisons can be the value of an attribute
3647: attached to an ancestor element. In this case, the attribute name is given
1.18 ! cvs 3648: instead of a constant value.</p>
! 3649: <p>
1.1 cvs 3650: It is also possible to write rules which apply only when a comparison between
3651: two different attributes of the element's ancestors is true. In this case, the
3652: first attribute name is followed by a comparison keyword and the name of the
1.18 ! cvs 3653: second attribute. The comparison keywords are <tt>EQUAL</tt> (simple
! 3654: equality), <tt>LESS</tt> (non-inclusive less than), and <tt>GREATER</tt>
! 3655: (non-inclusive greater than).</p>
! 3656: </dd>
! 3657: <dt>text attribute</dt>
! 3658: <dd>
! 3659: If the rules are to apply for one value of the attribute, then the attribute
! 3660: name is followed by an equals sign and this value.
! 3661: </dd>
! 3662: <dt>reference attribute</dt>
! 3663: <dd>
! 3664: There is never a value specification; the rules apply no matter what element
! 3665: is designated by the attribute.
! 3666: </dd>
! 3667: <dt>enumerated attribute</dt>
! 3668: <dd>
! 3669: If the rules are to apply for one value of the attribute, then the attribute
! 3670: name is followed by an equals sign and this value.
! 3671: </dd>
! 3672: </dl>
! 3673: <p>
1.1 cvs 3674: The order in which the rules associated with a numeric attribute are defined
3675: is important. When multiple sets of rules can be applied, the first set
1.18 ! cvs 3676: declared is the one used.</p>
! 3677: <p>
1.1 cvs 3678: Rules for attributes have priority over both default rules and rules
3679: associated with element types. The attribute rules apply to the element to
3680: which the attribute is attached. It is the rules which apply to the
3681: surrounding elements (and especially to the descendants) which determine the
3682: effect of the attribute rules on the environment ( and especially on the
1.18 ! cvs 3683: terminal elements of the structure).</p>
! 3684: <pre> 'ATTRIBUTES' PresAttrSeq
1.1 cvs 3685: PresAttrSeq = PresAttr < PresAttr > .
3686: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
3687: [ AttrRelation ] ':' ViewRuleSeq .
3688: AttrID = NAME .
3689: AttrRelation ='=' AttrVal /
3690: '>' [ '-' ] MinValue /
3691: '<' [ '-' ] MaxValue /
3692: 'IN' '[' [ '-' ] LowerBound '..'
3693: [ '-' ] UpperBound ']' /
3694: 'GREATER' AttrID /
3695: 'EQUAL' AttrID /
3696: 'LESS' AttrID .
3697: AttrVal = [ '-' ] EqualNum / EqualText /
3698: AttrValue .
3699: MinValue = NUMBER .
3700: MaxValue = NUMBER .
3701: LowerBound = NUMBER .
3702: UpperBound = NUMBER.
3703: EqualNum = NUMBER .
3704: EqualText = STRING .
1.18 ! cvs 3705: AttrValue = NAME .</pre>
! 3706: <p>
1.1 cvs 3707: In presentation rules associated with a numeric attribute (and only in such
3708: rules), the attribute name can be used in place of a numeric value. In this
3709: case, the value of the attribute is used in the application of the rule. Thus,
3710: the attribute can represent a relation between the size of two boxes, the
3711: height and width of a box, the height of an area where page breaks are
3712: prohibited, the distance between two boxes, the position of the reference axis
3713: of a box, the interline spacing, the indentation of the first line, the
1.18 ! cvs 3714: visibility, the depth (z-order), or the character set.</p>
! 3715: <p>
1.1 cvs 3716: The presentation rules associated with reference attributes, it is possible to
3717: use the element designated by the attribute as a reference box in a positional
1.18 ! cvs 3718: or extent rule. This element is represented in the <a
! 3719: href="#sectc4218">position</a> or <a href="#sectc4219">extent</a> rule by the
! 3720: keyword <tt>Referred</tt>.</p>
! 3721: <blockquote class="example">
! 3722: <p>
! 3723: <strong>Example:</strong></p>
! 3724: <p>
1.3 cvs 3725: In all structure schemas, there is a global Language attribute defined as
1.18 ! cvs 3726: follows:</p>
! 3727: <pre>ATTR
! 3728: Language = TEXT;</pre>
! 3729: <p>
! 3730: The following rules would make French text be displayed in roman characters
! 3731: and English text be displayed in italics:</p>
! 3732: <pre>ATTRIBUTES
1.1 cvs 3733: Language = 'French' :
1.6 cvs 3734: Style : Roman;
1.1 cvs 3735: Language = 'English' :
1.18 ! cvs 3736: Style : Italics;</pre>
! 3737: <p>
1.4 cvs 3738: Using these rules, when the user puts the Language attribute with the value
3739: 'English' on the summary of a document, every character string (terminal
1.18 ! cvs 3740: elements) contained in the summary are displayed in italics. See the <a
! 3741: href="#sectd42252"><tt>Style</tt> rule</a>.</p>
! 3742: </blockquote>
! 3743: <blockquote class="example">
! 3744: <p>
! 3745: <strong>Example:</strong></p>
! 3746: <p>
1.3 cvs 3747: A numeric attribute representing the importance of the part of the document to
1.18 ! cvs 3748: which it is attached can be defined:</p>
! 3749: <pre>ATTR
! 3750: Importance = INTEGER;</pre>
! 3751: <p>
1.4 cvs 3752: In the presentation schema, the importance of an element is reflected in the
1.18 ! cvs 3753: choice of character size, using the following rules.</p>
! 3754: <pre>ATTRIBUTES
1.1 cvs 3755: Importance < 2 :
3756: Size : 1;
3757: Importance IN [2..4] :
3758: Size : Importance;
3759: Importance = 10 :
3760: Size : 5;
3761: Importance > 4 :
1.18 ! cvs 3762: Size : 4;</pre>
! 3763: <p>
1.4 cvs 3764: Thus, the character size corresponds to the value of the Importance attribute;
1.18 ! cvs 3765: its value is</p>
! 3766: <ul>
! 3767: <li>
! 3768: the value of the Importance attribute when the value is between 2 and 4
1.1 cvs 3769: (inclusive),
1.18 ! cvs 3770: <li>
! 3771: 1, when the value of the Importance attribute is less than 2,
! 3772: <li>
! 3773: 4, when the value of the Importance attribute is greater than 4,
! 3774: <li>
! 3775: 5, when the value of the Importance attribute is 10.
! 3776: </ul>
! 3777: <p>
1.4 cvs 3778: The last case (value 5) must be defined before the case which handles all
3779: Importance values greater than 4, because the two rules are not disjoint and
3780: the first one defined will have priority. Otherwise, when the Importance
1.18 ! cvs 3781: attribute has value 10, the font size will be 4.</p>
! 3782: </blockquote>
! 3783: <blockquote class="example">
! 3784: <p>
! 3785: <strong>Example:</strong></p>
! 3786: <p>
1.3 cvs 3787: Suppose the structure defines a list element which can have an attribute
1.18 ! cvs 3788: defining the type of list (numbered or not):</p>
! 3789: <pre>STRUCT
1.1 cvs 3790: list (ATTR list_type = enumeration, dash)
1.18 ! cvs 3791: = LIST OF (list_item = TEXT);</pre>
! 3792: <p>
1.4 cvs 3793: Then, the presentation schema could use the attribute placed on the list
3794: element to put either a dash or a number before the each element of the
1.18 ! cvs 3795: list:</p>
! 3796: <pre>ATTRIBUTES
1.1 cvs 3797: list_type (list_item) = enumeration :
3798: CreateBefore (NumberBox);
3799: list_type (list_item) = dash :
1.18 ! cvs 3800: CreateBefore (DashBox);</pre>
! 3801: </blockquote>
! 3802: <blockquote class="example">
! 3803: <p>
! 3804: <strong>Example:</strong></p>
! 3805: <p>
1.3 cvs 3806: Suppose that two attributes are defined in the structure schema. The first is
3807: a numeric global attribute called ``version''. The other is a local attribute
1.18 ! cvs 3808: defined on the root of the document called ``Document_version'':</p>
! 3809: <pre>STRUCTURE Document
1.1 cvs 3810: ATTR
3811: version = INTEGER;
3812: STRUCT
3813: Document (ATTR Document_version = INTEGER) =
3814: BEGIN
3815: SomeElement ;
3816: ...
3817: SomeOtherElement ;
3818: END ;
1.18 ! cvs 3819: ...</pre>
! 3820: <p>
! 3821: These attributes can be used in the presentation schema to place change bars
! 3822: in the margin next to elements whose version attribute has a value equal to
! 3823: the Document_version attribute of the root and to place a star in margin of
1.4 cvs 3824: elements whose version attribute is less than the value of the root's
1.18 ! cvs 3825: Document_version attribute:</p>
! 3826: <pre>ATTRIBUTES
1.1 cvs 3827: version EQUAL Document_version :
3828: CreateBefore (ChangeBarBox) ;
3829: version LESS Document_version :
1.18 ! cvs 3830: CreateBefore (StarBox) ;</pre>
! 3831: </blockquote>
! 3832: </div>
1.1 cvs 3833:
1.18 ! cvs 3834: <div class="subsection">
1.1 cvs 3835:
1.18 ! cvs 3836: <h3><a name="sectc4212">Value transmission rules</a></h3>
! 3837: <p>
1.1 cvs 3838: The last section of a presentation schema, which is optional, serves to
3839: defines the way in which a document transmits certain values to its
1.18 ! cvs 3840: sub-documents. A sub-document is an document <a
! 3841: href="#inclusion">included</a> without expansion or with partial expansion.
1.1 cvs 3842: The primary document can transmit to its sub-documents the values of certain
3843: counters or the textual content of certain of its elements, as a function of
1.18 ! cvs 3844: their type.</p>
! 3845: <p>
1.1 cvs 3846: The sub-documents receive these values in attributes which must be defined in
3847: their structure schema as local attributes of the root element. The types of
3848: these attributes must correspond to the type of the value which they receive:
3849: numeric attributes for receiving the value of a counter, textual attributes
1.18 ! cvs 3850: for receiving the content of an element.</p>
! 3851: <p>
1.1 cvs 3852: In the structure schema of the primary document, there appears at the end,
1.18 ! cvs 3853: after the <tt>TRANSMIT</tt> keyword, a sequence of transmission rules. Each
1.1 cvs 3854: rule begins with the name of the counter to transmit or of the element type
3855: whose textual content will be transmitted. This name is followed by the
1.18 ! cvs 3856: keyword <tt>To</tt> and the name of the attribute of the sub-document to which
1.1 cvs 3857: the value is transmitted. The sub-document class is indicated between
3858: parentheses after the name of the attribute. The transmission rule ends with
1.18 ! cvs 3859: a semicolon.</p>
! 3860: <pre> TransmitSeq = Transmit < Transmit > .
1.1 cvs 3861: Transmit = TypeOrCounter 'To' ExternAttr
3862: '(' ElemID ')' ';' .
3863: TypeOrCounter = CounterID / ElemID .
1.18 ! cvs 3864: ExternAttr = NAME .</pre>
! 3865: <blockquote class="example">
! 3866: <p>
! 3867: <strong>Example:</strong></p>
! 3868: <p>
! 3869: Consider a Book document class which includes instances of the Chapter
! 3870: document class. These classes might have the following schemas:</p>
! 3871: <pre>STRUCTURE Book
1.1 cvs 3872: STRUCT
3873: Book = BEGIN
3874: Title = Text;
3875: Body = LIST OF (Chapter INCLUDED);
3876: END;
3877: ...
3878:
3879: STRUCTURE Chapter
3880: STRUCT
3881: Chapter (ATTR FirstPageNum = Integer;
3882: ChapterNum = Integer;
3883: CurrentTitle = Text) =
1.6 cvs 3884: BEGIN
3885: ChapterTitle = Text;
3886: ...
3887: END;
1.18 ! cvs 3888: ...</pre>
! 3889: <p>
1.1 cvs 3890: Then the presentation schema for books could define chapter and page counters.
3891: The following transmission rules in the book presentation schema would
3892: transmit values for the three attributes defined at the root of each chapter
1.18 ! cvs 3893: sub-document.</p>
! 3894: <pre>PRESENTATION Book;
1.1 cvs 3895: VIEWS
3896: Full_text;
3897: COUNTERS
3898: ChapterCtr: Rank of Chapter;
3899: PageCtr: Rank of Page(Full_text);
3900: ...
3901: TRANSMIT
3902: PageCtr TO FirstPageNum(Chapter);
3903: ChapterCtr TO ChapterNum(Chapter);
3904: Title TO CurrentTitle(Chapter);
1.18 ! cvs 3905: END</pre>
! 3906: <p>
1.1 cvs 3907: Thus, each chapter included in a book can number its pages as a function of
3908: the number of pages preceding it in the book, can make the chapter's number
3909: appear before the number of each of its sections, or can place the title of
1.18 ! cvs 3910: the book at the top of each page.</p>
! 3911: </blockquote>
! 3912: </div>
1.1 cvs 3913:
1.18 ! cvs 3914: <div class="subsection">
1.1 cvs 3915:
1.18 ! cvs 3916: <h3><a name="sectc4213">Presentation rules</a></h3>
! 3917: <p>
1.1 cvs 3918: Whether defining the appearance of a presentation or page layout box, an
3919: element type, or an attribute value, the set of presentation rules that apply
1.18 ! cvs 3920: is always defined in the same way.</p>
! 3921: <p>
1.1 cvs 3922: Normally, a set of presentation rules is placed between the keywords
1.18 ! cvs 3923: <tt>BEGIN</tt> and <tt>END</tt>, the keyword <tt>END</tt> being followed by a
1.1 cvs 3924: semicolon. The first section of this block defines the rules that apply to
1.18 ! cvs 3925: the primary view, if the <a href="#sectc427">default rules</a> are not
1.1 cvs 3926: completely suitable. Next comes the rules which apply to specific other
3927: views, with a rule sequence for each view for which the default rules are not
3928: satisfactory. If the default rules are suitable for the non-primary views,
3929: there will not be any specific rules for these views. If there is only one
1.18 ! cvs 3930: rule which applies to all views then the keywords <tt>BEGIN</tt> and
! 3931: <tt>END</tt> need not appear.</p>
! 3932: <p>
1.1 cvs 3933: For each view, it is only necessary to specify those rules which differ from
3934: the default rules for the view, so that for certain views (or even all views),
1.18 ! cvs 3935: there may be no specific rules.</p>
! 3936: <p>
! 3937: The specific rules for a non-primary view are introduced by the <a
! 3938: name="inkeyword"><tt>IN</tt> keyword</a>, followed by the view name. The
! 3939: rules for that view follow, delimited by the keywords <tt>BEGIN</tt> and
! 3940: <tt>END</tt>, or without these two keywords when there is only one rule.</p>
! 3941: <p>
! 3942: <strong>Note:</strong> the view name which follows the <tt>IN</tt> keyword
1.1 cvs 3943: must not be the name of the primary view, since the rules for that view are
1.18 ! cvs 3944: found before the rules for the other views.</p>
! 3945: <p>
1.1 cvs 3946: Within each block concerning a view, other blocks can appear, delimited by the
1.18 ! cvs 3947: same keywords <tt>BEGIN</tt> and <tt>END</tt>. Each of these blocks gathers
1.1 cvs 3948: the presentation rules that apply, for a given view, only when a given
3949: condition is satisfied. Each block is preceded by a condition introduced by
1.18 ! cvs 3950: the <tt>IF</tt> keyword. If such a conditional block contains only one rule,
! 3951: the keywords <tt>BEGIN</tt> and <tt>END</tt> can be omitted.</p>
! 3952: <p>
1.1 cvs 3953: Although the syntax allows any presentation rule to appear in a conditional
1.18 ! cvs 3954: block, only <a href="#sectc4232">creation rules</a> are allowed after any
! 3955: condition; other rules are allowed only after conditions <tt>Within</tt> and
1.1 cvs 3956: ElemID. In addition, the following rules cannot be conditional:
1.18 ! cvs 3957: <tt>PageBreak, LineBreak, Inline, Gather</tt>.</p>
! 3958: <p>
1.1 cvs 3959: For a given view, the rules that apply without any condition must appear
3960: before the first conditional block. If some rules apply only when none of the
3961: specified condition holds, they are grouped in a block preceded by the keyword
1.18 ! cvs 3962: <tt>Otherwise</tt>, and that block must appear after the last conditionnal
! 3963: block concerning the same view.</p>
! 3964: <pre> ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 3965: 'END' ';' /
3966: ViewRules / CondRules / Rule .
3967: RulesAndCond = CondRules / Rule .
3968: ViewRules = 'IN' ViewID CondRuleSeq .
3969: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
3970: CondRules / Rule .
3971: CondRules = CondRule < CondRule >
3972: [ 'Otherwise' RuleSeq ] .
3973: CondRule = 'IF' ConditionSeq RuleSeq .
3974: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' /
1.18 ! cvs 3975: Rule .</pre>
! 3976: <blockquote class="example">
! 3977: <p>
! 3978: <strong>Example:</strong></p>
! 3979: <p>
1.3 cvs 3980: The following rules for a report's title make the title visible in the primary
3981: view and invisible in the table of contents and in the formula views (see the
1.18 ! cvs 3982: <a href="#sectc4224"><tt>Visibility</tt> rule</a>).</p>
! 3983: <pre>Title : BEGIN
1.1 cvs 3984: Visibility : 1;
3985: ... {Other rules for the primary view}
3986: IN Table_of_contents
3987: Visibility : 0;
3988: IN Formulas
3989: Visibility : 0;
1.18 ! cvs 3990: END;</pre>
! 3991: </blockquote>
! 3992: </div>
1.1 cvs 3993:
1.18 ! cvs 3994: <div class="subsection">
1.1 cvs 3995:
1.18 ! cvs 3996: <h3><a name="sectc4214">Conditions applying to presentation rules</a></h3>
! 3997: <p>
1.1 cvs 3998: Many conditions can be applied to presentation rules. Conditions allow
3999: certain presentation rules to apply only in certain cases. These conditions
4000: can be based on the structural position of the element. They can be based on
4001: whether the element has references, and what type of references, whether the
4002: element has attributes, whether the element is empty or not. They can also be
1.18 ! cvs 4003: based on the value of a counter.</p>
! 4004: <p>
1.1 cvs 4005: It is possible to specify several conditions which must all be true for the
1.18 ! cvs 4006: rules to apply.</p>
! 4007: <p>
! 4008: A set of conditions is specified by the <tt>IF</tt> keyword. This keyword is
! 4009: followed by the sequence of conditions, separated by the <tt>AND</tt> keyword.
1.1 cvs 4010: Each condition is specified by a keyword which defines the condition type. In
4011: some cases, the keyword is followed by other data, which specify the condition
1.18 ! cvs 4012: more precisely.</p>
! 4013: <p>
1.1 cvs 4014: An elementary condition can be negative; it is then preceded by the
1.18 ! cvs 4015: <tt>NOT</tt> keyword.</p>
! 4016: <p>
1.1 cvs 4017: When the presentation rule(s) controlled by the condition apply to a reference
4018: element or a reference attribute, an elementary condition can also apply to
1.18 ! cvs 4019: element referred by this reference. The <tt>Target</tt> keyword is used for
1.1 cvs 4020: that purpose. It must appear before the keyword defining the condition
1.18 ! cvs 4021: type.</p>
! 4022: <pre> CondRule ='IF' ConditionSeq RuleSeq .
1.1 cvs 4023: ConditionSeq = Condition < 'AND' Condition > .
4024: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
4025: ConditionElem ='First' / 'Last' /
4026: [ 'Immediately' ] 'Within' [ NumParent ]
4027: ElemID [ ExtStruct ] /
4028: ElemID /
4029: 'Referred' / 'FirstRef' / 'LastRef' /
4030: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
4031: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
4032: 'UserPage' / 'StartPage' / 'ComputedPage' /
4033: 'Empty' /
4034: '(' [ MinMax ] CounterName CounterCond ')' /
4035: CondPage '(' CounterID ')' .
4036: NumParent = [ GreaterLess ] NParent .
1.6 cvs 4037: GreaterLess ='>' / '<' .
1.1 cvs 4038: NParent = NUMBER.
1.6 cvs 4039: ExtStruct ='(' ElemID ')' .
1.1 cvs 4040: CounterCond ='<' MaxCtrVal / '>' MinCtrVal /
4041: '=' EqCtrVal /
4042: 'IN' '[' ['-'] MinCtrBound '.' '.'
4043: ['-'] MaxCtrBound ']' .
4044: PageCond ='Even' / 'Odd' / 'One' .
4045: MaxCtrVal = NUMBER .
4046: MinCtrVal = NUMBER .
4047: EqCtrVal = NUMBER .
4048: MaxCtrBound = NUMBER .
1.18 ! cvs 4049: MinCtrBound = NUMBER .</pre>
1.1 cvs 4050:
1.18 ! cvs 4051: <div class="subsubsection">
1.1 cvs 4052:
1.18 ! cvs 4053: <h4><a name="sectd42141">Conditions based on the logical position of the
! 4054: element</a></h4>
! 4055: <p>
1.1 cvs 4056: The condition can be on the position of the element in the document's logical
4057: structure tree. It is possible to test whether the element is the first
1.18 ! cvs 4058: (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is not
! 4059: the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>). These
! 4060: conditions can be associated only with <a href="#sectc4232">creation
! 4061: rules</a>.</p>
! 4062: <p>
1.1 cvs 4063: It is also possible to test if the element is contained in an element of a
1.18 ! cvs 4064: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). The type
! 4065: is indicated after the keyword <tt>Within</tt>. If that element type is
1.1 cvs 4066: defined in a structure schema which is not the one which corresponds to the
4067: presentation schema, the type name of this element must be followed, between
1.18 ! cvs 4068: parentheses, by the name of the structure schema which defines it.</p>
! 4069: <p>
! 4070: If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
! 4071: condition is satisfied only if the <em>parent</em> element has the type
! 4072: indicated. If the word <tt>Immediately</tt> is missing, the condition is
! 4073: satisfied if any <em>ancestor</em> has the type indicated.</p>
! 4074: <p>
! 4075: An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.1 cvs 4076: type. It specifies the number of ancestors of the indicated type that must be
4077: present for the condition to be satisfied. If the keyword
1.18 ! cvs 4078: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
! 4079: element must have the indicated type. The integer <i>n</i> must be positive
! 4080: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
1.1 cvs 4081: maximum or minimum number of ancestors. If these symbols are missing, the
1.18 ! cvs 4082: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
! 4083: this number is missing, it is equivalent to > 0.</p>
! 4084: <p>
1.1 cvs 4085: If the condition applies to presentation rules associated with an attribute,
1.18 ! cvs 4086: in the <tt>ATTRIBUTES</tt> section of the presentation schema, the condition
1.1 cvs 4087: can be simply an element name. Presentation rules are then executed only if
1.18 ! cvs 4088: the attribute is attached to an element of that type. The keyword <tt>NOT</tt>
1.1 cvs 4089: before the element name indicates that the presentation rules must be executed
1.18 ! cvs 4090: only if the element is not of the type indicated.</p>
! 4091: </div>
1.1 cvs 4092:
1.18 ! cvs 4093: <div class="subsubsection">
1.1 cvs 4094:
1.18 ! cvs 4095: <h4><a name="sectd42142">Conditions on references</a></h4>
! 4096: <p>
1.1 cvs 4097: References may be taken into account in conditions, which can be based on the
4098: fact that the element, or one of its ancestors, is designated by a at least
1.18 ! cvs 4099: one reference (<tt>Referred</tt>) or by none (<tt>NOT Referred</tt>).</p>
! 4100: <p>
1.1 cvs 4101: If the element or attribute to which the condition is attached is a reference,
4102: the condition can be based on the fact that it acts as the first reference to
1.18 ! cvs 4103: the designated element (<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>),
1.1 cvs 4104: or as a reference to an element located in another document
1.18 ! cvs 4105: (<tt>ExternalRef</tt>) or in the same document (<tt>InternalRef</tt>).</p>
! 4106: <p>
! 4107: The condition can also be based on the fact that the element is an <a
! 4108: href="#inclusion">inclusion</a>. This is noted (<tt>CopyRef</tt>).</p>
! 4109: <p>
1.1 cvs 4110: Like all conditions, conditions on references can be inverted by the
1.18 ! cvs 4111: <tt>NOT</tt> keyword. These conditions can be associated only with <a
! 4112: href="#sectc4232">creation rules</a>.</p>
! 4113: </div>
1.1 cvs 4114:
1.18 ! cvs 4115: <div class="subsubsection">
1.1 cvs 4116:
1.18 ! cvs 4117: <h4><a name="sectd42143">Conditions on logical attributes</a></h4>
! 4118: <p>
1.1 cvs 4119: The condition can be based on the presence or absence of attributes associated
4120: with the element, no matter what the attributes or their values. The
1.18 ! cvs 4121: <tt>AnyAttributes</tt> keyword expresses this condition.</p>
! 4122: <p>
1.1 cvs 4123: If the condition appears in the presentation rules of an attribute, the
1.18 ! cvs 4124: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
1.1 cvs 4125: the rules must only be applied if this attribute is the first attribute for
4126: the element or if it is the last (respectively). These conditions can also be
1.18 ! cvs 4127: inverted by the <tt>NOT</tt> keyword. These conditions can be associated only
! 4128: with <a href="#sectc4232">creation rules</a>.</p>
! 4129: <p>
1.1 cvs 4130: It is also possible to apply certain presentation rules only when the element
4131: being processed or one of its ancestors has a certain attribute, perhaps with
1.18 ! cvs 4132: a certain value. This can be done in the <a
! 4133: href="#sectc4210"><tt>ATTRIBUTES</tt> section</a>.</p>
! 4134: </div>
1.1 cvs 4135:
1.18 ! cvs 4136: <div class="subsubsection">
1.1 cvs 4137:
1.18 ! cvs 4138: <h4><a name="sectd42144">Conditions on page breaks</a></h4>
! 4139: <p>
1.1 cvs 4140: The page break base type (and only this type) can use the following
1.18 ! cvs 4141: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, and <tt>UserPage</tt>.
! 4142: The <tt>ComputedPage</tt> condition indicates that the presentation rule(s)
1.1 cvs 4143: should apply if the page break was created automatically by Thot; the
1.18 ! cvs 4144: <tt>StartPage</tt> condition is true if the page break is generated before the
! 4145: element by the <tt>Page</tt> rule; and the <tt>UserPage</tt> condition applies
! 4146: if the page break was inserted by the user.</p>
! 4147: <p>
! 4148: These conditions can be associated only with <a href="#sectc4232">creation
! 4149: rules</a>.</p>
! 4150: </div>
1.1 cvs 4151:
1.18 ! cvs 4152: <div class="subsubsection">
1.1 cvs 4153:
1.18 ! cvs 4154: <h4><a name="sectd42145">Conditions on the element's content</a></h4>
! 4155: <p>
1.1 cvs 4156: The condition can be based on whether or not the element is empty. An element
4157: which has no children or whose leaves are all empty is considered to be empty
1.18 ! cvs 4158: itself. This condition is expressed by the <tt>Empty</tt> keyword, optionally
! 4159: preceded by the <tt>NOT</tt> keyword. This condition can be associated only
! 4160: with <a href="#sectc4232">creation rules</a>.</p>
! 4161: </div>
1.1 cvs 4162:
1.18 ! cvs 4163: <div class="subsubsection">
1.1 cvs 4164:
1.18 ! cvs 4165: <h4><a name="sectd42146">Conditions on counters</a></h4>
! 4166: <p>
1.1 cvs 4167: Presentation rules can apply when the counter's value is one, is even or odd,
4168: is equal, greater than or less than a given value or falls in a range of
4169: values. This is particularly useful for creating header and footer boxes.
1.18 ! cvs 4170: These conditions can be associated only with <a href="#sectc4232">creation
! 4171: rules</a>.</p>
! 4172: <p>
1.1 cvs 4173: To compare the value of a counter to a given value, a comparison is given
4174: between parentheses. The comparison is composed of the counter name followed
4175: by an equals, greater than, or less than sign and the value to which the
4176: counter will be compared. A test for whether or not a counter's value falls
4177: in a range also appears within parentheses. In this case, the counter name is
1.18 ! cvs 4178: followed by the <tt>IN</tt> keyword and the range definition within brackets.
! 4179: The <tt>Even</tt>, <tt>Odd</tt> and <tt>One</tt> are used to test a counter's
! 4180: value and are followed by the counter name between parentheses.</p>
! 4181: <p>
! 4182: The list of possible conditions on counters is:</p>
! 4183: <dl>
! 4184: <dt><tt>Even (Counter)</tt></dt>
! 4185: <dd>
! 4186: the box is created only if the counter has an even value.
! 4187: </dd>
! 4188: <dt><tt>Odd (Counter)</tt></dt>
! 4189: <dd>
! 4190: the box is created only if the counter has an odd value.
! 4191: </dd>
! 4192: <dt><tt>One (Counter)</tt></dt>
! 4193: <dd>
! 4194: the box is created only the counter's value is 1.
! 4195: </dd>
! 4196: <dt><tt>NOT One (Counter)</tt></dt>
! 4197: <dd>
! 4198: the box is created, unless the counter's value is 1.
! 4199: </dd>
! 4200: <dt><tt>(Counter < Value)</tt></dt>
! 4201: <dd>
! 4202: the box is created only if the counter's value is less than Value.
! 4203: </dd>
! 4204: <dt><tt>(Counter > Value)</tt></dt>
! 4205: <dd>
! 4206: the box is created only if the counter's value is greater than Value.
! 4207: </dd>
! 4208: <dt><tt>(Counter = Value)</tt></dt>
! 4209: <dd>
! 4210: the box is created only if the counter's value is equal to Value.
! 4211: </dd>
! 4212: <dt><tt>NOT (Counter = Value)</tt></dt>
! 4213: <dd>
! 4214: the is created only if the counter's value is different than Value.
! 4215: </dd>
! 4216: <dt><tt>(Counter IN [MinValue..MaxValue])</tt></dt>
! 4217: <dd>
! 4218: the box is created only if the counter's value falls in the range bounded by
! 4219: MinValue and MaxValue (inclusive).
! 4220: </dd>
! 4221: <dt><tt>NOT (Counter IN [MinValue..MaxValue])</tt></dt>
! 4222: <dd>
! 4223: the box is created only if the value of the counter does not fall in the range
! 4224: bounded by MinValue and MaxValue (inclusive).
! 4225: </dd>
! 4226: </dl>
! 4227: <p>
! 4228: <strong>Note:</strong> the <tt>NOT Even</tt> and <tt>NOT Odd</tt> conditions
! 4229: are syntactically correct but can be expressed more simply by <tt>Odd</tt> and
! 4230: <tt>Even</tt>, respectively.</p>
! 4231: </div>
! 4232: </div>
1.1 cvs 4233:
1.18 ! cvs 4234: <div class="subsection">
1.1 cvs 4235:
1.18 ! cvs 4236: <h3><a name="sectc4215">A presentation rule</a></h3>
! 4237: <p>
1.1 cvs 4238: A presentation rule defines either a presentation parameter or presentation
1.18 ! cvs 4239: function. The parameters are:</p>
! 4240: <ul>
! 4241: <li>
! 4242: the position of the vertical and horizontal reference axes of the box,
! 4243: <li>
! 4244: the position of the box in relation to other boxes,
! 4245: <li>
! 4246: the height or width of the box, with overflow exceptions,
! 4247: <li>
! 4248: the characteristics of the lines contained in the box: linespacing,
1.1 cvs 4249: indentation of the first line, justification, hyphenation,
1.18 ! cvs 4250: <li>
! 4251: the conditions for breaking the box across pages,
! 4252: <li>
! 4253: the characteristics of the characters contained in the box: size, font, style,
! 4254: underlining,
! 4255: <li>
! 4256: the depth of the box among overlapping boxes (often called stacking order),
! 4257: <li>
! 4258: the characteristics of graphic elements contained in the box: style and
1.1 cvs 4259: thickness of lines, fill pattern for closed objects,
1.18 ! cvs 4260: <li>
! 4261: the colors in text, graphics, pictures, and symbols contained in the box are
! 4262: displayed or printed,
! 4263: <li>
! 4264: for presentation boxes only, the contents of the box.
! 4265: </ul>
! 4266: <p>
! 4267: The <a name="presfunct">presentation functions</a> are:</p>
! 4268: <ul>
! 4269: <li>
! 4270: the creation of a presentation box
! 4271: <li>
! 4272: the line-breaking or page-breaking style,
! 4273: <li>
! 4274: the copying of another box,
! 4275: <li>
! 4276: the display of the box background and border,
! 4277: <li>
! 4278: the display of a background picture and its aspect.
! 4279: </ul>
! 4280: <p>
1.1 cvs 4281: For each box and each view, every presentation parameter is defined once and
1.18 ! cvs 4282: only once, either explicitly or by the <a href="#sectc427">default rules</a>.
! 4283: In contrast, presentation functions are not obligatory and can appear many
! 4284: times for the same element. for example an element can create many
! 4285: presentation boxes. Another element may not use any presentation
! 4286: functions.</p>
! 4287: <p>
1.1 cvs 4288: Each rule defining a presentation parameter begins with a keyword followed by
1.18 ! cvs 4289: a colon. The keyword indicates the parameter which is the subject of the
! 4290: rule. After the keyword and the colon, the remainder of the rule varies. All
! 4291: rules are terminated by a semicolon.</p>
! 4292: <pre> Rule = PresParam ';' / PresFunc ';' .
1.6 cvs 4293: PresParam ='VertRef' ':' PositionHoriz /
4294: 'HorizRef' ':' PositionVert /
4295: 'VertPos' ':' VPos /
4296: 'HorizPos' ':' HPos /
4297: 'Height' ':' Dimension /
4298: 'Width' ':' Dimension /
4299: 'VertOverflow' ':' Boolean /
1.1 cvs 4300: 'HorizOverflow' ':' Boolean /
1.6 cvs 4301: 'LineSpacing' ':' DistanceInherit /
4302: 'Indent' ':' DistanceInherit /
4303: 'Adjust' ':' AdjustInherit /
4304: 'Justify' ':' BoolInherit /
4305: 'Hyphenate' ':' BoolInherit /
4306: 'PageBreak' ':' Boolean /
4307: 'LineBreak' ':' Boolean /
4308: 'InLine' ':' Boolean /
4309: 'NoBreak1' ':' AbsDist /
4310: 'NoBreak2' ':' AbsDist /
4311: 'Gather' ':' Boolean /
4312: 'Visibility' ':' NumberInherit /
4313: 'Size' ':' SizeInherit /
4314: 'Font' ':' NameInherit /
4315: 'Style' ':' StyleInherit /
4316: 'Underline' ':' UnderLineInherit /
4317: 'Thickness' ':' ThicknessInherit /
4318: 'Depth' ':' NumberInherit /
4319: 'LineStyle' ':' LineStyleInherit /
4320: 'LineWeight' ':' DistanceInherit /
4321: 'FillPattern' ':' NameInherit /
4322: 'Background' ':' NameInherit /
1.13 cvs 4323: 'Foreground' ':' NameInherit /
1.6 cvs 4324: 'Content' ':' VarConst .
1.1 cvs 4325: PresFunc = Creation '(' BoxID ')' /
4326: 'Line' /
4327: 'NoLine' /
4328: 'Page' '(' BoxID ')' /
1.13 cvs 4329: 'Copy' '(' BoxTypeToCopy ')' /
4330: 'ShowBox' /
1.18 ! cvs 4331: 'BackgroundPicture' ':' FileName /
! 4332: 'PictureMode' ':' PictMode /</pre>
! 4333: </div>
! 4334:
! 4335: <div class="subsection">
! 4336:
! 4337: <h3><a name="sectc4216">Box axes</a></h3>
! 4338: <p>
! 4339: The position of the middle axes <tt>VMiddle</tt> and <tt>HMiddle</tt> in
1.1 cvs 4340: relation to their box is always calculated automatically as a function of the
4341: height and width of the box and is not specified by the presentation rules. In
4342: the presentation schema, these middle axes are used only to position their box
4343: with respect to another by specifying the distance between the middle axis and
1.18 ! cvs 4344: an axis or a side of another box (see the <a href="#sectc4218">relative
! 4345: position</a>).</p>
! 4346: <p>
1.1 cvs 4347: The reference axes of a box are also used to position their box in relation to
4348: another, but in contrast to the middle axes, the presentation schema must make
4349: their position explicit, either in relation to a side or the middle axis of
1.18 ! cvs 4350: the box itself, or in relation to an axis of an enclosed box.</p>
! 4351: <p>
1.1 cvs 4352: Only boxes of base elements have predefined reference axes. For character
4353: string boxes, the horizontal reference axis is the baseline of the characters
4354: (the line which passes immediately under the upper-case letters, ignoring the
4355: letter Q) and the vertical reference axis is at the left edge of the first
1.18 ! cvs 4356: character of the string.</p>
! 4357: <p>
! 4358: The positions of a box's reference axes are defined by the <tt>VertRef</tt>
! 4359: and <tt>HorizRef</tt> rules which specify the <a href="#distance">distance</a>
1.1 cvs 4360: between the reference axis and an axis or parallel side of the same box or of
1.18 ! cvs 4361: an enclosed box.</p>
! 4362: <pre> 'VertRef' ':' PositionHoriz
! 4363: 'HorizRef' ':' PositionVert</pre>
! 4364: <blockquote class="example">
! 4365: <p>
! 4366: <strong>Example:</strong></p>
! 4367: <p>
1.3 cvs 4368: If, in the structure schema for mathematical formulas, the fraction element is
1.18 ! cvs 4369: defined by</p>
! 4370: <pre>Fraction = BEGIN
1.1 cvs 4371: Numerator = Expression;
4372: Denominator = Expression;
1.18 ! cvs 4373: END;</pre>
! 4374: <p>
1.3 cvs 4375: then the horizontal reference axis of the fraction can be positioned on top of
1.18 ! cvs 4376: the denominator by the rule:</p>
! 4377: <pre>Fraction :
1.1 cvs 4378: BEGIN
4379: HorizRef : Enclosed Denominator . Top;
4380: ...
1.18 ! cvs 4381: END;</pre>
! 4382: <p>
! 4383: To put the horizontal reference axis of a column at its middle:</p>
! 4384: <pre>Column :
1.1 cvs 4385: BEGIN
4386: HorizRef : * . HMiddle;
4387: ...
1.18 ! cvs 4388: END;</pre>
! 4389: </blockquote>
! 4390: </div>
1.1 cvs 4391:
1.18 ! cvs 4392: <div class="subsection">
1.1 cvs 4393:
1.18 ! cvs 4394: <h3><a name="sectc4217">Distance units</a></h3>
! 4395: <p>
1.1 cvs 4396: Some distances and dimensions appear in many rules of a presentation schema,
1.18 ! cvs 4397: especially in position rules (<tt>VertPos, HorizPos</tt>), in extent rules for
! 4398: boxes (<tt>Height, Width</tt>), in rules defining lines (<tt>LineSpacing,
! 4399: Indent</tt>), in rules controlling pagination (<tt>NoBreak1, NoBreak2</tt>)
! 4400: and in rules specifying the thickness of strokes (<tt>LineWeight</tt>).</p>
! 4401: <p>
! 4402: In all these rules, the distance or extent can be expressed</p>
! 4403: <ul>
! 4404: <li>
! 4405: either in relative units, which depend on the size of the characters in the
! 4406: current font: height of the element's font or height of the letter 'x',
! 4407: <li>
! 4408: or in absolute units: centimeter, millimeter, inch, typographer's point, pica
! 4409: or pixel.
! 4410: </ul>
! 4411: <p>
1.5 cvs 4412: Units can be chosen freely. Thus, it is possible to use relative units in one
1.18 ! cvs 4413: rule, centimeters in the next rule, and typographer's points in another.</p>
! 4414: <p>
1.1 cvs 4415: Absolute units are used to set rigid rules for the appearance of documents. In
4416: contrast, relative units allow changes of scale. The editor lets the value of
4417: relative units be changed dynamically. Such changes affect every box using
4418: relative units simultaneously and in the same proportion. Changing the value
4419: of the relative units affects the size of the characters and graphical
1.18 ! cvs 4420: elements, and the size of the boxes and the distances between them.</p>
! 4421: <p>
! 4422: A <a name="distance">distance</a> or extent is specified by a number, which
1.1 cvs 4423: may be followed by one or more spaces and a units keyword. When there is no
4424: units keyword, the number specifies the number of relative units, where a
4425: relative unit is the height of a character in the current font (an em). When
4426: the number is followed by a units keyword, the keyword indicates the type of
1.18 ! cvs 4427: absolute units:</p>
! 4428: <ul>
! 4429: <li>
! 4430: <tt>em</tt>: height of the element's font,
! 4431: <li>
! 4432: <tt>ex</tt>: height of the letter 'x',
! 4433: <li>
! 4434: <tt>cm</tt>: centimeter,
! 4435: <li>
! 4436: <tt>mm</tt>: millimeter,
! 4437: <li>
! 4438: <tt>in</tt>: inch (1 in = 2.54 cm),
! 4439: <li>
! 4440: <tt>pt</tt>: point (1 pt = 1/72 in),
! 4441: <li>
! 4442: <tt>pc</tt>: pica (1 pc = 12 pt),
! 4443: <li>
! 4444: <tt>px</tt>: pixel.
! 4445: </ul>
! 4446: <p>
1.1 cvs 4447: Whatever the chosen unit, relative or absolute, the number is not necessarily
4448: an integer and may be expressed in fixed point notation (using the American
1.18 ! cvs 4449: convention of a period to express the decimal point).</p>
! 4450: <p>
1.1 cvs 4451: If the distance appears in a presentation rule for a numeric attribute, the
4452: number can be replaced by the name of an attribute. In this case, the value
4453: of the attribute is used. Obviously, the attribute name cannot be followed by
4454: a decimal point and a fractional part, but it can be followed a units keyword.
1.18 ! cvs 4455: However, the choice of units is limited to em, ex, pt and px.</p>
! 4456: <pre> Distance = [ Sign ] AbsDist .
1.1 cvs 4457: Sign ='+' / '-' .
4458: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
4459: [ Unit ].
4460: IntegerOrAttr = IntegerPart / AttrID .
4461: IntegerPart = NUMBER .
4462: DecimalPart = NUMBER .
4463: Unit ='em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
1.18 ! cvs 4464: 'pc' / 'px' / '%' .</pre>
! 4465: <blockquote class="example">
! 4466: <p>
! 4467: <strong>Example:</strong></p>
! 4468: <p>
1.3 cvs 4469: The following rules specify that a box has a height of 10.5 centimeters and a
1.18 ! cvs 4470: width of 5.3 ems:</p>
! 4471: <pre>Height : 10.5 cm;
! 4472: Width : 5.3;</pre>
! 4473: </blockquote>
! 4474: </div>
1.1 cvs 4475:
1.18 ! cvs 4476: <div class="subsection">
1.1 cvs 4477:
1.18 ! cvs 4478: <h3><a name="sectc4218">Relative positions</a></h3>
! 4479: <p>
1.1 cvs 4480: The positioning of boxes uses the eight axes and sides, the sides generally
4481: being used to define the juxtapositioning (vertical or horizontal) of boxes,
4482: the middle axes being used to define centering, and the reference axes being
1.18 ! cvs 4483: used for alignment.</p>
! 4484: <p>
! 4485: Two rules allow a box to be placed relative to other boxes. The
! 4486: <tt>VertPos</tt> rule positions the box vertically. The <tt>HorizPos</tt>
! 4487: rule positions the box horizontally. It is possible that a box's position
! 4488: could be entirely determined by other boxes positioned relative to it. In this
! 4489: case, the position is implicit and the word <tt>nil</tt> can be used to
! 4490: specify that no position rule is needed. Otherwise, an explicit rule must be
! 4491: given by indicating the axis or side which defines the position of the box,
! 4492: followed by an equals sign and the distance between between this axis or side
! 4493: and a parallel axis or side of another box, called the reference box. The box
! 4494: for which the rule is written will be positioned relative to the reference
! 4495: box.</p>
! 4496: <pre> 'VertPos' ':' VPos
1.6 cvs 4497: 'HorizPos' ':' HPos
4498: HPos = 'nil' / VertAxis '=' HorizPosition
4499: [ 'UserSpecified' ].
4500: VPos = 'nil' / HorizAxis '=' VertPosition
4501: [ 'UserSpecified' ].
1.1 cvs 4502: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
1.18 ! cvs 4503: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .</pre>
! 4504: <p>
1.1 cvs 4505: The reference box is an adjacent box: enclosing, enclosed or adjacent. When a
4506: rule is associated with a reference type attribute (and only in this case), it
4507: can be a box of the element designated by the attribute. The reference box
1.18 ! cvs 4508: can be either a presentation box previously defined in the <tt>BOXES</tt>
1.1 cvs 4509: section of the schema and created by a creation function, or the box
1.18 ! cvs 4510: associated with a structured element.</p>
! 4511: <p>
1.1 cvs 4512: The structural position of the reference box (relative to the box for which
1.18 ! cvs 4513: the rule is being written) is indicated by a keyword: <tt>Enclosing</tt>,
! 4514: <tt>Enclosed</tt>, or, for sibling boxes, <tt>Previous</tt> or <tt>Next</tt>.
1.1 cvs 4515: The reference attributes, or presentation boxes created by a reference
1.18 ! cvs 4516: attribute, the <tt>Referred</tt> keyword may be used to designate the element
! 4517: which the reference points to. The keyword <tt>Creator</tt> can be used in
1.1 cvs 4518: rules for presentation boxes to designate the box of the element which created
1.18 ! cvs 4519: the presentation box. Finally, the <tt>Root</tt> keyword can be used to
! 4520: designate the root of the document.</p>
! 4521: <p>
! 4522: When the keyword is ambiguous, it is followed by the name of an element type
! 4523: or presentation box which resolves the ambiguity (the <tt>Creator</tt> and
! 4524: <tt>Root</tt> keywords are never ambiguous). If this name is not given, then
1.1 cvs 4525: the first box encountered is used as the reference box. It is also possible to
1.18 ! cvs 4526: use just the name of an element type or presentation box without an initial
! 4527: keyword. In this case, a sibling having that name will be used. If the name
! 4528: is preceded by the keyword <tt>NOT</tt>, then the reference box will be the
! 4529: first box whose type is not the named one.</p>
! 4530: <p>
! 4531: In place of the box or type name, the keywords <tt>AnyElem</tt>,
! 4532: <tt>AnyBox</tt> and <tt>ElemWithAttr</tt> can be used, representing
1.17 cvs 4533: respectively, any structured element box, any presentation box, and the box
4534: corresponding to any structured element having a particular attribute,
4535: whatever its value; the name of this attribute must follow the keyword
1.18 ! cvs 4536: <tt>ElemWithAttr</tt>.</p>
! 4537: <p>
1.17 cvs 4538: A type name may be preceded by a star in order to resolve the ambiguity in the
1.18 ! cvs 4539: special case where the structure schema defines an <a
! 4540: href="#sectd3284">inclusion</a> without expansion (or with partial expansion)
! 4541: of the same type as an element of the scheme. For mark pairs (and only for <a
! 4542: href="#sectd3285">mark pairs</a>) the type name <em>must</em> be preceded by
! 4543: the <tt>First</tt> or <tt>Second</tt> keyword, which indicates which of the
! 4544: two marks of the pair should be used as the reference box.</p>
! 4545: <p>
! 4546: The star character ('<tt>*</tt>') used alone designates the box to which the
1.1 cvs 4547: rule applies (in this case, it is obviously useless to specify the type of the
1.18 ! cvs 4548: reference box).</p>
! 4549: <p>
! 4550: The keywords <tt>Enclosing</tt> and <tt>Enclosed</tt> can be used no matter
1.1 cvs 4551: what constructor defines the type to which the rule applies. When applied to
1.18 ! cvs 4552: the element which represents the entire document, <tt>Enclosing</tt>
1.1 cvs 4553: designates the window or page in which the document's image is displayed for
4554: the view to which the rule applies. A box or type name without a keyword is
4555: used for aggregate elements and designates another element of the same
4556: aggregate. It can also be used to designate a presentation or page layout
1.18 ! cvs 4557: box. The keywords <tt>Previous</tt> and <tt>Next</tt> are primarily used to
1.1 cvs 4558: denote list elements, but can also be used to denote elements of an
1.18 ! cvs 4559: aggregate.</p>
! 4560: <p>
1.1 cvs 4561: In the position rule, the structural position relative to the reference box is
4562: followed, after a period, by the name of an axis or side. The rule specifies
4563: its node's position as being some distance from this axis or side of the
4564: reference box. If this distance is zero, then the distance does not appear in
4565: the rule. Otherwise, it does appear as a positive or negative number (the
4566: sign is required for negative numbers). The sign takes into account the
4567: orientation of the coordinate axes: for top to bottom for the vertical axis
4568: and from left to right for the horizontal axis. Thus, a negative distance in
4569: a vertical position indicates that the side or axis specified in the rule is
1.18 ! cvs 4570: above the side or axis of the reference box.</p>
! 4571: <p>
! 4572: The distance can be followed by the <tt>UserSpecified</tt> keyword (even if
! 4573: the distance is nil and does not appear, the <tt>UserSpecified</tt> keyword
1.1 cvs 4574: can be used). It indicates that when the element to which the rule applies is
4575: being created, the editor will ask the user to specify the distance himself,
4576: using the mouse. In this case, the distance specified in the rule is a
4577: default distance which is suggested to the user but can be modified. The
1.18 ! cvs 4578: <tt>UserSpecified</tt> keyword can be used either in the vertical position
! 4579: rule, the horizontal position rule, or both.</p>
! 4580: <pre> VertPosition = Reference '.' HorizAxis [ Distance ] .
1.1 cvs 4581: HorizPosition = Reference '.' VertAxis [ Distance ] .
4582: Reference ='Enclosing' [ BoxTypeNot ] /
4583: 'Enclosed' [ BoxTypeNot ] /
4584: 'Previous' [ BoxTypeNot ] /
4585: 'Next' [ BoxTypeNot ] /
4586: 'Referred' [ BoxTypeNot ] /
4587: 'Creator' /
4588: 'Root' /
4589: '*' /
4590: BoxOrType .
4591: BoxOrType = BoxID /
4592: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 4593: 'AnyElem' / 'AnyBox' /
4594: 'ElemWithAttr' AttrID .
1.18 ! cvs 4595: BoxTypeNot = [ 'NOT' ] BoxOrType .</pre>
! 4596: <blockquote class="example">
! 4597: <p>
! 4598: <strong>Example:</strong></p>
! 4599: <p>
! 4600: If a <a name="expos1">report</a> is defined by the following structure
! 4601: schema:</p>
! 4602: <pre>Report = BEGIN
1.6 cvs 4603: Title = Text;
4604: Summary = Text;
4605: Keywords = Text;
4606: ...
1.18 ! cvs 4607: END;</pre>
! 4608: <p>
! 4609: then the presentation schema could contain the rules:</p>
! 4610: <pre>Report : BEGIN
1.6 cvs 4611: VertPos : Top = Enclosing . Top;
4612: HorizPos : Left = Enclosing . Left;
4613: ...
1.18 ! cvs 4614: END;</pre>
! 4615: <p>
! 4616: These rules place the <a name="reportexample">report</a> in the upper left
! 4617: corner of the enclosing box, which is the window in which the document is
! 4618: being edited.</p>
! 4619: <pre>Title : BEGIN
1.6 cvs 4620: VertPos : Top = Enclosing . Top + 1;
4621: HorizPos : VMiddle = Enclosing . VMiddle;
4622: ...
1.18 ! cvs 4623: END;</pre>
! 4624: <p>
1.3 cvs 4625: The top of the title is one line (a line has the height of the characters of
4626: the title) from the top of the report, which is also the top of the editing
1.18 ! cvs 4627: window. The title is centered horizontally in the window (see <a
! 4628: href="#posdim">figure</a>).</p>
! 4629: <pre>Summary : BEGIN
1.1 cvs 4630: VertPos : Top = Title . Bottom + 1.5;
4631: HorizPos : Left = Enclosing . Left + 2 cm;
4632: ...
1.18 ! cvs 4633: END;</pre>
! 4634: <p>
! 4635: The top of the summary is place a line and a half below the bottom of the
! 4636: title and is shifted two centimeters from the side of the window.</p>
! 4637: </blockquote>
! 4638: <blockquote class="example">
! 4639: <p>
! 4640: <strong>Example:</strong></p>
! 4641: <p>
! 4642: Suppose there is a <a name="expos2">Design</a> logical structure which
! 4643: contains graphical elements:</p>
! 4644: <pre>Design = LIST OF (ElemGraph = GRAPHICS);</pre>
! 4645: <p>
1.3 cvs 4646: The following rules allow the user to freely choose the position of each
1.18 ! cvs 4647: element when it is created:</p>
! 4648: <pre>ElemGraph =
1.1 cvs 4649: BEGIN
4650: VertPos : Top = Enclosing . Top + 1 cm UserSpecified;
4651: HorizPos: Left = Enclosing . Left UserSpecified;
4652: ...
1.18 ! cvs 4653: END;</pre>
! 4654: <p>
! 4655: Thus, when a graphical element is created, its default placement is at the
! 4656: left of the window and 1 cm from the top, but the user can move it
! 4657: immediately, simply by moving the mouse.</p>
! 4658: </blockquote>
! 4659: </div>
1.1 cvs 4660:
1.18 ! cvs 4661: <div class="subsection">
1.1 cvs 4662:
1.18 ! cvs 4663: <h3><a name="sectc4219">Box extents</a></h3>
! 4664: <p>
1.1 cvs 4665: The extents (height and width) of each box are defined by the two rules
1.18 ! cvs 4666: <tt>Height</tt> and <tt>Width</tt>. There are three types of extents: fixed,
! 4667: relative, and elastic.</p>
1.1 cvs 4668:
1.18 ! cvs 4669: <div class="subsubsection">
1.1 cvs 4670:
1.18 ! cvs 4671: <h4><a name="sectd42191">Fixed extents</a></h4>
! 4672: <p>
1.1 cvs 4673: A fixed dimension sets the height or width of the box independently of all
1.18 ! cvs 4674: other boxes. It is expressed in <a href="#sectc4217">distance units</a>. The
! 4675: extent can be followed by the <tt>UserSpecified</tt> keyword which indicates
1.1 cvs 4676: that when the element to which the rule applies is being created, the editor
4677: will ask the user to specify the extent himself, using the mouse. In this
4678: case, the extent specified in the rule is a default extent which is suggested
1.18 ! cvs 4679: to the user but can be modified. The <tt>UserSpecified</tt> keyword can be
! 4680: used either in the <tt>Height</tt> rule, the <tt>Width</tt> rule, or both.</p>
! 4681: <p>
! 4682: A fixed extent rule can be ended by the <tt>Min</tt> keyword, which signifies
1.1 cvs 4683: that the indicated value is a minimum, and that, if the contents of the box
1.18 ! cvs 4684: require it, a larger extent is possible.</p>
! 4685: <pre> 'Height' ':' Dimension
1.1 cvs 4686: 'Width' ':' Dimension
4687: Dimension = AbsDist [ 'UserSpecified' ] [ 'Min' ] /
1.18 ! cvs 4688: ...</pre>
! 4689: <blockquote class="example">
! 4690: <p>
! 4691: <strong>Example:</strong></p>
! 4692: <p>
! 4693: Continuing with the <a href="#expos2">previous example</a>, it is possible to
1.3 cvs 4694: allow the user to choose the size of each graphical element as it is
1.18 ! cvs 4695: created:</p>
! 4696: <pre>ElemGraph : BEGIN
1.6 cvs 4697: Width : 2 cm UserSpecified;
1.1 cvs 4698: Height : 1 cm UserSpecified;
4699: ...
1.18 ! cvs 4700: END;</pre>
! 4701: <p>
1.1 cvs 4702: Thus, when a graphical element is create, it is drawn by default with a width
4703: of 2 cm and a height of 1 cm, but the user is free to resize it immediately
1.18 ! cvs 4704: with the mouse.</p>
! 4705: <pre>Summary : BEGIN
1.1 cvs 4706: Height : 5 cm Min;
4707: ...
4708: END;
4709: Keywords : BEGIN
4710: VertPos : Top = Summary . Bottom;
4711: ...
1.18 ! cvs 4712: END;</pre>
! 4713: </blockquote>
! 4714: </div>
1.1 cvs 4715:
1.18 ! cvs 4716: <div class="subsubsection">
1.1 cvs 4717:
1.18 ! cvs 4718: <h4><a name="sectd42192">Relative extents</a></h4>
! 4719: <p>
1.1 cvs 4720: A relative extent determines the extent as a function of the extent of another
4721: box, just as a relative position places a box in relation to another. The
4722: reference box in an extent rule is designated using the same syntax as is used
1.18 ! cvs 4723: in a relative position rule. It is followed by a period and a <tt>Height</tt>
! 4724: or <tt>Width</tt> keyword, depending on the extent being referred to. Next
1.1 cvs 4725: comes the relation between the extent being defined and the extent of the
1.18 ! cvs 4726: reference box. This relation can be either a percentage or a difference.</p>
! 4727: <p>
1.1 cvs 4728: A percentage is indicated by a star (the multiplication symbol) followed by
4729: the numeric percentage value (which may be greater than or less than 100) and
4730: the percent (`%') character. A difference is simply indicated by a signed
1.18 ! cvs 4731: difference.</p>
! 4732: <p>
1.1 cvs 4733: If the rule appears in the presentation rules of a numeric attribute, the
4734: percentage value can be replaced by the name of the attribute. This attribute
1.18 ! cvs 4735: is then used as a percentage. The attribute can also be used as part of a <a
! 4736: href="#distance">difference</a>.</p>
! 4737: <p>
1.1 cvs 4738: Just as with a fixed extent, a relative extent rule can end with the
1.18 ! cvs 4739: <tt>Min</tt> keyword, which signifies that the extent is a minimum and that,
! 4740: if the contents of the box require it, a larger extent is possible.</p>
! 4741: <p>
! 4742: A special case of relative extent rules is:</p>
! 4743: <pre>Height : Enclosed . Height;</pre>
! 4744: <p>
! 4745: or</p>
! 4746: <pre>Width : Enclosed . Width;</pre>
! 4747: <p>
1.5 cvs 4748: which specifies that the box has a height (or width) such that it encloses all
1.18 ! cvs 4749: the boxes which it contains, excluding boxes having a rule <tt>VertOverflow:
! 4750: Yes;</tt> or <tt>HorizOverflow: Yes;</tt>.</p>
! 4751: <p>
! 4752: <strong>Note:</strong> character strings (type <tt>TEXT_UNIT</tt>) generally
1.1 cvs 4753: must use the sum of the widths of the characters which compose them as their
1.18 ! cvs 4754: width, which is expressed by the rule:</p>
! 4755: <pre>TEXT_UNIT :
! 4756: Width : Enclosed . Width;</pre>
! 4757: <p>
! 4758: If this rule is not the default <tt>Width</tt> rule, it must be given
! 4759: explicitly in the <tt>RULES</tt> section which defines the presentation rules
! 4760: of the logical elements.</p>
! 4761: <pre> 'Height' ':' Extent
1.1 cvs 4762: 'Width' ':' Extent
4763: Extent = Reference '.' HeightWidth [ Relation ]
4764: [ 'Min' ] / ...
4765: HeightWidth ='Height' / 'Width' .
4766: Relation ='*' ExtentAttr '%' / Distance .
4767: ExtentAttr = ExtentVal / AttrID .
1.18 ! cvs 4768: ExtentVal = NUMBER .</pre>
! 4769: <blockquote class="example">
! 4770: <p>
! 4771: <strong>Example:</strong></p>
! 4772: <p>
! 4773: Completing the <a href="#expos1">above example</a>, it is possible to specify
! 4774: that the report takes its width from the editing window and its height from
! 4775: the size of its contents (this can obviously be greater than that of the
! 4776: window):</p>
! 4777: <pre>Report : BEGIN
1.1 cvs 4778: Width : Enclosing . Width;
4779: Height : Enclosed . Height;
4780: ...
1.18 ! cvs 4781: END;</pre>
! 4782: <p>
1.3 cvs 4783: Then, the following rules make the title occupy 60% of the width of the report
4784: (which is that of the window) and is broken into centered lines of this width
1.18 ! cvs 4785: (see the <a href="#sectc4222"><tt>Line</tt> rule</a>).</p>
! 4786: <pre>Title : BEGIN
1.1 cvs 4787: Width : Enclosing . Width * 60%;
4788: Height : Enclosed . Height;
4789: Line;
4790: Adjust : VMiddle;
4791: ...
1.18 ! cvs 4792: END;</pre>
! 4793: <p>
! 4794: The summary occupy the entire width of the window, with the exception of a 2
! 4795: cm margin reserved by the horizontal position rule:</p>
! 4796: <pre>Summary : BEGIN
1.1 cvs 4797: Width : Enclosing . Width - 2 cm;
4798: Height : Enclosed . Height;
4799: ...
1.18 ! cvs 4800: END;</pre>
! 4801: <p>
! 4802: This set of rules, plus the <a href="#reportexample">position rules given
! 4803: above</a>, produce the layout of boxes shown in the following<a
! 4804: href="#posdim">figure</a>.</p>
! 4805:
! 4806: <div class="figure">
! 4807: <hr>
! 4808: <pre>-------------------------------------------------------------
1.1 cvs 4809: | Window and Report ^ |
4810: | | 1 line |
4811: | v |
4812: | ------------------------------------- |
4813: | | | |
4814: : 20% : Title : 20% :
4815: :<--------->: :<--------->:
4816: : : 60% : :
4817: : :<--------------------------------->: :
4818: | | | |
4819: | ------------------------------------- |
4820: | ^ |
4821: | | 1.5 line |
4822: | | |
4823: | v |
4824: | ---------------------------------------------------|
4825: | 2 cm | |
4826: |<------>| Summary |
1.18 ! cvs 4827: : : :</pre>
! 4828: <p align=center>
! 4829: <em><a name="posdim">Box position and extent</a><em></em></em></p>
! 4830: <hr>
! 4831: </div>
! 4832: </blockquote>
! 4833: </div>
1.1 cvs 4834:
1.18 ! cvs 4835: <div class="subsubsection">
1.1 cvs 4836:
1.18 ! cvs 4837: <h4><a name="sectd42193">Elastic extents</a></h4>
! 4838: <p>
1.1 cvs 4839: The last type of extent is the elastic extent. Either one or both extents can
4840: be elastic. A box has an elastic extent when two opposite sides are linked by
1.18 ! cvs 4841: distance constraints to two sides or axes of other boxes.</p>
! 4842: <p>
1.1 cvs 4843: One of the sides of the elastic box is linked by a position rule
1.18 ! cvs 4844: (<tt>VertPos</tt> or <tt>HorizPos</tt>) to a neighboring box. The other side
! 4845: is link to another box by a <tt>Height</tt> or <tt>Width</tt> rule, which
1.1 cvs 4846: takes the same form as the position rule. For the elastic box itself, the
4847: notions of sides (left or right, top or bottom) are fuzzy, since the movement
4848: of either one of the two reference boxes can, for example, make the left side
4849: of the elastic box move to the right of its right side. This is not
4850: important. The only requirement is that the two sides of the elastic box used
1.18 ! cvs 4851: in the position and extent rule are opposite sides of the box.</p>
! 4852: <pre> 'Height' ':' Extent
1.6 cvs 4853: 'Width' ':' Extent
1.18 ! cvs 4854: Extent = HPos / VPos / ...</pre>
! 4855: <blockquote class="example">
! 4856: <p>
! 4857: <strong>Example:</strong></p>
! 4858: <p>
1.3 cvs 4859: Suppose we want to draw an elastic arrow or line between the middle of the
4860: bottom side of box A and the upper left corner of box B. To do this, we would
4861: define a graphics box whose upper left corner coincides with the middle of the
4862: bottom side of A (a position rule) and whose lower right corner coincides with
1.18 ! cvs 4863: with the upper left corner of B (dimension rules):</p>
! 4864: <pre>LinkedBox :
1.1 cvs 4865: BEGIN
1.6 cvs 4866: VertPos : Top = A .Bottom;
1.1 cvs 4867: HorizPos : Left = A . VMiddle;
1.6 cvs 4868: Height : Bottom = B . Top;
4869: Width : Right = B . Left;
1.18 ! cvs 4870: END;</pre>
! 4871: </blockquote>
! 4872: <blockquote class="example">
! 4873: <p>
! 4874: <strong>Example:</strong></p>
! 4875: <p>
1.3 cvs 4876: The element SectionTitle creates a presentation box called SectionNum which
4877: contains the number of the section. Suppose we want to align the SectionNum
4878: and SectionTitle horizontally, have the SectionNum take its width from its
4879: contents (the section number), have the SectionTitle box begin 0.5 cm to the
4880: right of the SectionNum box and end at the right edge of its enclosing box.
1.18 ! cvs 4881: This would make the SectionTitle box elastic, since its width is defined by
! 4882: the position of its left and right sides. The following rules produce this
! 4883: effect:</p>
! 4884: <pre>SectionNum :
1.1 cvs 4885: BEGIN
4886: HorizPos : Left = Enclosing . Left;
4887: Width : Enclosed . Width;
4888: ...
4889: END;
4890:
4891: SectionTitle :
4892: BEGIN
4893: HorizPos : Left = SectionNum . Right + 0.5 cm;
4894: Width : Right = Enclosing . Right;
4895: ...
1.18 ! cvs 4896: END;</pre>
! 4897: </blockquote>
! 4898: </div>
! 4899: </div>
1.1 cvs 4900:
1.18 ! cvs 4901: <div class="subsection">
1.1 cvs 4902:
1.18 ! cvs 4903: <h3><a name="sectc4220">Overflow</a></h3>
! 4904: <p>
1.1 cvs 4905: A boxes corresponding to a structural element normally contain all boxes
4906: corresponding to the elements of its subtree. However, in some cases, it
4907: could be necessary to allow a box to jut out from its parent box. Two
4908: presentation rules indicate that such an overflow is allowed, one for
1.18 ! cvs 4909: horizontal overflow, one for vertical overflow.</p>
! 4910: <p>
1.1 cvs 4911: Each of these rules is expressed by a keyword followed by a colon and the
1.18 ! cvs 4912: keyword <tt>Yes</tt> or <tt>No</tt>.</p>
! 4913: <pre> 'VertOverflow' ':' Boolean /
1.1 cvs 4914: 'HorizOverflow' ':' Boolean .
1.18 ! cvs 4915: Boolean = 'Yes' / 'No' .</pre>
! 4916: </div>
1.1 cvs 4917:
1.18 ! cvs 4918: <div class="subsection">
1.1 cvs 4919:
1.18 ! cvs 4920: <h3><a name="sectc4221">Inheritance</a></h3>
! 4921: <p>
1.1 cvs 4922: A presentation parameter can be defined by reference to the same parameter of
4923: another box in the tree of boxes. These structural links are expressed by
4924: kinship. The reference box can be that of the element immediately above in
1.18 ! cvs 4925: the structure (<tt>Enclosing</tt>), two levels above (<tt>GrandFather</tt>),
! 4926: immediately below (<tt>Enclosed</tt>) or immediately before
! 4927: (<tt>Previous</tt>). In the case of a presentation box, and only in that
1.1 cvs 4928: case, the reference box may be the element which created the presentation box
1.18 ! cvs 4929: (<tt>Creator</tt>).</p>
! 4930: <p>
1.1 cvs 4931: Kinship is expressed in terms of the logical structure of the document and not
4932: in terms of the tree of boxes. The presentation box cannot transmit any of
4933: their parameters by inheritance; only structured element boxes can do so. As
4934: an example, consider an element B which follows an element A in the logical
4935: structure. The element B creates a presentation box P in front of itself,
1.18 ! cvs 4936: using the <tt>CreateBefore</tt> rule (see the <a href="#sectc4232">creation
! 4937: rules</a>). If element B's box inherits its character style using the
! 4938: <tt>Previous</tt> kinship operation, it gets its character style from A's box,
1.1 cvs 4939: not from P's box. Inheritance works differently for positions and extents,
1.18 ! cvs 4940: which can refer to presentation boxes.</p>
! 4941: <p>
1.1 cvs 4942: The inherited parameter value can be the same as that of the reference box.
4943: This is indicated by an equals sign. However, for numeric parameters, a
4944: different value can be obtained by adding or subtracting a number from the
4945: reference box's parameter value. Addition is indicated by a plus sign before
4946: the number, while subtraction is specified with a minus sign. The value of a
4947: parameter can also be given a maximum (if the sign is a plus) or minimum (if
1.18 ! cvs 4948: the sign is a minus).</p>
! 4949: <p>
1.1 cvs 4950: If the rule is being applied to a numeric attribute, the number to add or
4951: subtract can be replaced by the attribute name. The value of a maximum or
4952: minimum may also be replaced by an attribute name. In these cases, the value
1.18 ! cvs 4953: of the attribute is used.</p>
! 4954: <pre> Inheritance = Kinship InheritedValue .
1.6 cvs 4955: Kinship ='Enclosing' / 'GrandFather' / 'Enclosed' /
4956: 'Previous' / 'Creator' .
1.1 cvs 4957: InheritedValue ='+' PosIntAttr [ 'Max' maximumA ] /
1.6 cvs 4958: '-' NegIntAttr [ 'Min' minimumA ] /
4959: '=' .
4960: PosIntAttr = PosInt / AttrID .
4961: PosInt = NUMBER .
4962: NegIntAttr = NegInt / AttrID .
4963: NegInt = NUMBER .
4964: maximumA = maximum / AttrID .
4965: maximum = NUMBER .
4966: minimumA = minimum / AttrID .
1.18 ! cvs 4967: minimum = NUMBER .</pre>
! 4968: <p>
1.1 cvs 4969: The parameters which can be obtained by inheritance are justification,
4970: hyphenation, interline spacing, character font (font family), font style, font
4971: size, visibility, indentation, underlining, alignment of text, stacking order
4972: of objects, the style and thickness of lines, fill pattern and the colors of
1.18 ! cvs 4973: lines and characters.</p>
! 4974: </div>
1.1 cvs 4975:
1.18 ! cvs 4976: <div class="subsection">
1.1 cvs 4977:
1.18 ! cvs 4978: <h3><a name="sectc4222">Line breaking</a></h3>
! 4979: <p>
! 4980: The <tt>Line</tt> rule specifies that the contents of the box should be broken
1.1 cvs 4981: into lines: the boxes included in the box to which this rule is attached are
4982: displayed one after the other, from left to right, with their horizontal
4983: reference axes aligned so that they form a series of lines. The length of
1.18 ! cvs 4984: these lines is equal to the width of the box to which the <tt>Line</tt> rule
! 4985: is attached.</p>
! 4986: <p>
1.1 cvs 4987: When an included box overflows the current line, it is either carried forward
1.18 ! cvs 4988: to the next line, cur, or left the way it is. The <a
! 4989: href="#sectc4223"><tt>LineBreak</tt> rule</a> is used to allow or prevent the
1.1 cvs 4990: breaking of included boxes. If the included box is not breakable but is
4991: longer than the space remaining on the line, it is left as is. When a
4992: character string box is breakable, the line is broken between words or, if
1.18 ! cvs 4993: necessary, by <a href="#sectd42225">hyphenating a word</a>. When a compound
! 4994: box is breakable, the box is transparent in regard to line breaking. The boxes
! 4995: included in the compound box are treated just like included boxes which have
! 4996: the <tt>LineBreak</tt> rule. Thus, it is possible to traverse a complete
! 4997: subtree of boxes to line break the text leaves of a complex structure.</p>
! 4998: <p>
1.1 cvs 4999: The relative position rules of the included boxes are ignored, since the boxes
1.18 ! cvs 5000: will be placed according to the line breaking rules.</p>
! 5001: <p>
! 5002: The <tt>Line</tt> rule does not have a parameter. The characteristics of the
! 5003: lines that will be constructed are determined by the <tt>LineSpacing</tt>,
! 5004: <tt>Indent</tt>, <tt>Adjust</tt>, <tt>Justify</tt>, and <tt>Hyphenate</tt>
! 5005: rules. Moreover, the <a href="#insectd42226"><tt>Inline</tt> rule</a> permits
! 5006: the exclusion of certain elements from the line breaking process.</p>
! 5007: <p>
! 5008: When the <tt>Line</tt> rule appears in the rules sequence of a non-primary
! 5009: view, it applies only to that view, but when the <tt>Line</tt> rule appears in
1.1 cvs 5010: the rules sequence of the primary view, it also applies to the other views by
1.18 ! cvs 5011: default, except for those views which explicitly invoke the <tt>NoLine</tt>
! 5012: rule. Thus, the <tt>NoLine</tt> rule can be used in a non-primary view to
! 5013: override the primary view's <tt>Line</tt> rule. The <tt>NoLine</tt> rule must
! 5014: not be used with the primary view because the absence of the <tt>Line</tt>
! 5015: rule has the same effect. Like the <tt>Line</tt> rule, the <tt>NoLine</tt>
! 5016: rule does not take any parameters.</p>
! 5017: <pre> 'Line'
! 5018: 'NoLine'</pre>
! 5019:
! 5020: <div class="subsubsection">
! 5021:
! 5022: <h4><a name="sectd42221">Line spacing</a></h4>
! 5023: <p>
! 5024: The <tt>LineSpacing</tt> rule defines the line spacing to be used in the line
1.1 cvs 5025: breaking process. The line spacing is the distance between the baselines
5026: (horizontal reference axis) of the successive lines produced by the
1.18 ! cvs 5027: <tt>Line</tt> rule. The value of the line spacing can be specified as a
! 5028: constant or by inheritance. It is expressed in any of the available <a
! 5029: href="#sectc4217">distance units</a>.</p>
! 5030: <p>
1.1 cvs 5031: Inheritance allows the value to be obtained from a relative in the structure
5032: tree, either without change (an equals sign appears after the inheritance
5033: keyword), with a positive difference (a plus sign), or a negative difference
5034: (a minus sign). When the rule uses a difference, the value of the difference
1.18 ! cvs 5035: follows the sign and is expressed as a <a href="#sectc4217">distance</a>.</p>
! 5036: <pre> 'LineSpacing' ':' DistOrInherit
1.6 cvs 5037: DistOrInherit = Kinship InheritedDist / Distance .
1.18 ! cvs 5038: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .</pre>
! 5039: <p>
1.1 cvs 5040: When the line spacing value (or its difference from another element) is
5041: expressed in relative units, it changes with the size of the characters. Thus,
5042: when a larger font is chosen for a part of the document, the line spacing of
5043: that part expands proportionally. In contrast, when the line spacing value is
5044: expressed in absolute units (centimeters, inches, typographer's points), it is
5045: independent of the characters, which permits the maintenance of a consistent
5046: line spacing, whatever the character font. Either approach can be taken,
1.18 ! cvs 5047: depending on the desired effect.</p>
! 5048: </div>
1.1 cvs 5049:
1.18 ! cvs 5050: <div class="subsubsection">
1.1 cvs 5051:
1.18 ! cvs 5052: <h4><a name="sectd42222">First line indentation</a></h4>
! 5053: <p>
! 5054: The <tt>Indent</tt> rule is used to specify the indentation of the first line
! 5055: of the elements broken into lines by the <tt>Line</tt> function. The
1.1 cvs 5056: indentation determines how far the first line of the element is shifted with
5057: respect to the other lines of the same element. It can be specified as a
5058: constant or by inheritance. The constant value is a positive integer (shifted
5059: to the right; the sign is optional), a negative integer (shifted to the left)
1.18 ! cvs 5060: or zero (no shift). All available <a href="#sectc4217">units</a> can be
! 5061: used.</p>
! 5062: <p>
1.1 cvs 5063: Indentation can be defined for any box, regardless of whether the box is line
5064: broken, and transmitted by inheritance to elements that are line broken. The
1.18 ! cvs 5065: size of the indentation is specified in the same manner as the <a
! 5066: href="#sectd42221">line spacing</a>.</p>
! 5067: <pre> 'Indent' ':' DistOrInherit</pre>
! 5068: </div>
1.1 cvs 5069:
1.18 ! cvs 5070: <div class="subsubsection">
1.1 cvs 5071:
1.18 ! cvs 5072: <h4><a name="sectd42223">Alignment</a></h4>
! 5073: <p>
1.1 cvs 5074: The alignment style of the lines constructed during line breaking is defined
1.18 ! cvs 5075: by the <tt>Adjust</tt> rule. The alignment value can be a constant or
! 5076: inherited. A constant value is specified by a keyword:</p>
! 5077: <ul>
! 5078: <li>
! 5079: <tt>Left</tt>: at the left edge,
! 5080: <li>
! 5081: <tt>Right</tt>: at the right edge,
! 5082: <li>
! 5083: <tt>VMiddle</tt>: centered
! 5084: <li>
! 5085: <tt>LeftWithDots</tt>: at the left edge with a dotted line filling out the
1.1 cvs 5086: last line up to the right edge of the line breaking box.
1.18 ! cvs 5087: </ul>
! 5088: <p>
1.1 cvs 5089: An inherited value can only be the same as that of the reference box and is
1.18 ! cvs 5090: specified by a kinship keyword followed by an equals sign.</p>
! 5091: <pre> 'Adjust' ':' AlignOrInherit
1.1 cvs 5092: AlignOrInherit = Kinship '=' / Alignment .
5093: Alignment = 'Left' / 'Right' / 'VMiddle' /
1.18 ! cvs 5094: 'LeftWithDots' .</pre>
! 5095: </div>
1.1 cvs 5096:
1.18 ! cvs 5097: <div class="subsubsection">
1.1 cvs 5098:
1.18 ! cvs 5099: <h4><a name="sectd42224">Justification</a></h4>
! 5100: <p>
! 5101: The <tt>Justify</tt> rule indicates whether the lines contained in the box and
! 5102: produced by a <tt>Line</tt> rule should be extended horizontally to occupy the
1.1 cvs 5103: entire width of their enclosing box. The first and last lines are treated
5104: specially: the position of the beginning of the first line is fixed by the
1.18 ! cvs 5105: <tt>Indent</tt> rule and last line is not extended. The justification
1.1 cvs 5106: parameter defined by this rule takes a boolean value, which can be a constant
5107: or inherited. A constant boolean value is expressed by either the
1.18 ! cvs 5108: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 5109: same as that of the reference box and is specified by a kinship keyword
1.18 ! cvs 5110: followed by an equals sign.</p>
! 5111: <pre> 'Justify' ':' BoolInherit
1.1 cvs 5112: BoolInherit = Boolean / Kinship '=' .
1.18 ! cvs 5113: Boolean ='Yes' / 'No' .</pre>
! 5114: <p>
1.1 cvs 5115: When the lines are justified, the alignment parameter specified in the
1.18 ! cvs 5116: <tt>Adjust</tt> rule has no influence, other than on the last line produced.
1.1 cvs 5117: This occurs because, when the other are extended to the limits of the box, the
1.18 ! cvs 5118: alignment style is no longer perceptible.</p>
! 5119: <blockquote class="example">
! 5120: <p>
! 5121: <strong>Example:</strong></p>
! 5122: <p>
1.3 cvs 5123: An important use of inheritance is to vary the characteristics of lines for an
5124: element type (for example, Paragraph) according to the enclosing environment
5125: (for example, Summary or Section), and thus obtain different line breaking
5126: styles for the same elements when they appear in different environments. The
1.18 ! cvs 5127: following rules specify that paragraphs inherit their alignment,
! 5128: justification, and line spacing:</p>
! 5129: <pre>Paragraph :
1.1 cvs 5130: BEGIN
5131: Justify : Enclosing = ;
5132: LineSpacing : Enclosing = ;
5133: Adjust : Enclosing =;
5134: Line;
1.18 ! cvs 5135: END;</pre>
! 5136: <p>
1.5 cvs 5137: If the alignment, justification, and line spacing of the Section and Summary
1.18 ! cvs 5138: elements is fixed:</p>
! 5139: <pre>Section :
1.1 cvs 5140: BEGIN
5141: Adjust : Left;
5142: Justify : Yes;
5143: LineSpacing : 1;
5144: END;
5145: Summary :
5146: BEGIN
5147: Adjust : VMiddle;
5148: Justify : No;
5149: LineSpacing : 1.3;
1.18 ! cvs 5150: END;</pre>
! 5151: <p>
1.4 cvs 5152: then the paragraphs appearing in sections are justified with a simple line
5153: spacing while those appearing in summaries are centered and not justified and
5154: have a larger line spacing. These are nevertheless the very same type of
1.18 ! cvs 5155: paragraph defined in the logical structure schema.</p>
! 5156: </blockquote>
! 5157: </div>
! 5158:
! 5159: <div class="subsubsection">
! 5160:
! 5161: <h4><a name="sectd42225">Hyphenation</a></h4>
! 5162: <p>
! 5163: The <tt>Hyphenate</tt> rule indicates whether or not words should be broken by
1.1 cvs 5164: hyphenation at the end of lines. It affects the lines produced by the
1.18 ! cvs 5165: <tt>Line</tt> rule and contained in the box carrying the <tt>Hyphenate</tt>
! 5166: rule.</p>
! 5167: <p>
1.1 cvs 5168: The hyphenation parameter takes a boolean value, which can be either constant
5169: or inherited. A constant boolean value is expressed by either the
1.18 ! cvs 5170: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 5171: same as that of the reference box and is specified by a kinship keyword
1.18 ! cvs 5172: followed by an equals sign.</p>
! 5173: <pre> 'Hyphenate' ':' BoolInherit
1.1 cvs 5174: BoolInherit = Boolean / Kinship '=' .
1.18 ! cvs 5175: Boolean = 'Yes' / 'No' .</pre>
! 5176: </div>
! 5177:
! 5178: <div class="subsubsection">
! 5179:
! 5180: <h4><a name="sectd42226">Avoiding line breaking</a></h4>
! 5181: <p>
! 5182: The <tt>InLine</tt> rule is used to specify that a box that would otherwise
! 5183: participate in line breaking asked for by the <tt>Line</tt> rule of an
1.1 cvs 5184: enclosing box, instead avoids the line breaking process and positions itself
1.18 ! cvs 5185: according to the <tt>HorizPos</tt> and <tt>VertPos</tt> rules that apply to
! 5186: it. When the <tt>InLine</tt> rule applies to a box which would not be line
! 5187: broken, it has no effect.</p>
! 5188: <p>
! 5189: The rule is expressed by the <tt>InLine</tt> keyword followed by a colon and
! 5190: the keyword <tt>Yes</tt>, if the box should participate in line breaking, or
! 5191: the keyword <tt>No</tt>, if it should not. This is the only form possible:
1.1 cvs 5192: this rule cannot be inherited. Moreover, it can only appear in the rules of
5193: the primary view and applies to all views defined in the presentation
1.18 ! cvs 5194: schema.</p>
! 5195: <pre> 'InLine' ':' Boolean .
! 5196: Boolean = 'Yes' / 'No' .</pre>
! 5197: <blockquote class="example">
! 5198: <p>
! 5199: <strong>Example:</strong></p>
! 5200: <p>
! 5201: Suppose the structure schema defines a logical attribute called <tt>New</tt>
! 5202: which is used to identify the passages in a document which were recently
! 5203: modified. It would be nice to have the presentation schema make a bar appear
! 5204: in the left margin next to each passage having the <tt>New</tt> attribute. A
! 5205: new passage can be an entire element, such as a paragraph or section, or it
! 5206: can be some words in the middle of a paragraph. To produce the desired
! 5207: effect, the <tt>New</tt> attribute is given a creation rule which generates a
! 5208: <tt>VerticalBar</tt> presentation box.</p>
! 5209: <p>
! 5210: When the <tt>New</tt> attribute is attached to a character string which is
1.1 cvs 5211: inside a line broken element (inside a paragraph, for example), the bar is one
5212: of the elements which participates in line breaking and it is placed normally
5213: in the current line, at the end of the character string which has the
1.18 ! cvs 5214: attribute. To avoid this, the <tt>InLine</tt> rule is used in the following
! 5215: way:</p>
! 5216: <pre>BOXES
1.1 cvs 5217: VerticalBar:
5218: BEGIN
5219: Content: Graphics 'l';
5220: HorizPos: Left = Root . Left;
5221: VertPos: Top = Creator . Top;
5222: Height: Bottom = Creator . Bottom;
5223: Width: 1 pt;
5224: InLine: No;
5225: ...
5226: END;
5227: ...
5228: ATTRIBUTES
5229: Nouveau:
5230: BEGIN
5231: CreateAfter(VerticalBar);
1.18 ! cvs 5232: END;</pre>
! 5233: </blockquote>
! 5234: </div>
! 5235: </div>
1.1 cvs 5236:
1.18 ! cvs 5237: <div class="subsection">
1.1 cvs 5238:
1.18 ! cvs 5239: <h3><a name="sectc4223">Page breaking and line breaking conditions</a></h3>
! 5240: <p>
1.1 cvs 5241: Pages are constructed by the editor in accordance with the model specified by
1.18 ! cvs 5242: a <a href="#sectc4233"><tt>Page</tt> rule</a>. The page model describes only
! 5243: the composition of the pages but does not give any rules for breaking
! 5244: different element types across pages. Now, it is possible that certain
! 5245: elements must not be cut by page breaks, while others can be cut anywhere. The
! 5246: <tt>PageBreak</tt>, <tt>NoBreak1</tt>, and <tt>NoBreak2</tt> rules are used to
! 5247: specify the conditions under which each element type can be cut.</p>
! 5248: <p>
! 5249: The <tt>PageBreak</tt> rule is used to indicate whether or not the box can be
1.1 cvs 5250: cut during the construction of pages. If cutting is authorized, the box can
5251: be cut, with one part appearing at the bottom of a page and the other part
5252: appearing at the top of the next page. The rule is formed by the
1.18 ! cvs 5253: <tt>PageBreak</tt> keyword followed by a colon and a constant boolean value
! 5254: (<tt>Yes</tt> or <tt>No</tt>). This is the only form possible: this rule
1.1 cvs 5255: cannot be inherited. Moreover, it can only appear in the rules of the primary
1.18 ! cvs 5256: view and applies to all views defined in the presentation schema.</p>
! 5257: <p>
1.1 cvs 5258: Whether objects can be cut by line breaks can be controlled in a similar way
1.18 ! cvs 5259: using the <tt>LineBreak</tt> rule. This rule allows the specification of
1.1 cvs 5260: whether or not the box can be cut during the construction of lines. If
5261: cutting is authorized, the box can be cut, with one part appearing at the end
5262: of a line and the other part appearing at the beginning of the next line. The
1.18 ! cvs 5263: rule is formed by the <tt>LineBreak</tt> keyword followed by a colon and a
! 5264: constant boolean value (<tt>Yes</tt> or <tt>No</tt>). This is the only form
1.1 cvs 5265: possible: this rule cannot be inherited. Moreover, it can only appear in the
5266: rules of the primary view and applies to all views defined in the presentation
1.18 ! cvs 5267: schema.</p>
! 5268: <pre> 'PageBreak' ':' Boolean .
1.1 cvs 5269: 'LineBreak' ':' Boolean .
1.18 ! cvs 5270: Boolean = 'Yes' / 'No' .</pre>
! 5271: <p>
1.1 cvs 5272: When a box can be cut by a page break, it is possible that a page break will
5273: fall an inappropriate spot, creating, for example, a widow or orphan, or
5274: separating the title of a section from the first paragraph of the section. The
1.18 ! cvs 5275: <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules are used to avoid this. They
! 5276: specify that the box of the element to which they apply cannot be cut within a
! 5277: certain zone at the top (<tt>NoBreak1</tt> rule) or at the bottom
! 5278: (<tt>NoBreak2</tt> rule). These two rules specify the height of the zones in
! 5279: which page breaks are prohibited.</p>
! 5280: <p>
! 5281: The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules give the height of the zone
1.1 cvs 5282: in which page breaking is prohibited. The height is given as a constant value
1.18 ! cvs 5283: using any of the <a href="#sectc4217">available units</a>, absolute or
! 5284: relative. The value may not be inherited.</p>
! 5285: <pre> 'NoBreak1' ':' AbsDist .
! 5286: 'NoBreak2' ':' AbsDist .</pre>
! 5287: <blockquote class="example">
! 5288: <p>
! 5289: <strong>Example:</strong></p>
! 5290: <p>
! 5291: The following rules prevent widows and orphans in a paragraph:</p>
! 5292: <pre>Paragraph :
1.1 cvs 5293: BEGIN
5294: NoBreak1 : 2;
5295: NoBreak2 : 2;
1.18 ! cvs 5296: END;</pre>
! 5297: <p>
1.3 cvs 5298: This rule prevents a section title from becoming separated from the first
5299: paragraph of the section by prohibiting page breaks at the beginning of the
1.18 ! cvs 5300: section rule:</p>
! 5301: <pre>Section :
! 5302: NoBreak1 : 1.5 cm;</pre>
! 5303: <p>
! 5304: Finally, this rule prevents a figure from being page broken in any way:</p>
! 5305: <pre>Figure :
! 5306: PageBreak : No;</pre>
! 5307: </blockquote>
! 5308: <p>
1.1 cvs 5309: The Thot editor constructs the document images displayed on the screen
5310: dynamically. As the user moves in the document or makes the document scroll
5311: in a window, the editor constructs the image to be displayed in little bits,
5312: filling the gaps which are produced in the course of these operations. It
5313: stops filling in the image when an element reaches the edge of the window in
5314: which the gap appears. If the appearance of the document is complex, it is
5315: possible that the image in incomplete, even though the edge of the window was
5316: reached. For example, an element might need to be presented to the side of
5317: the last element displayed, but its image was not constructed. The user will
5318: not know whether the element is really absent or if its image has simply not
1.18 ! cvs 5319: been constructed.</p>
! 5320: <p>
! 5321: The <tt>Gather</tt> rule is used to remedy this problem. When the rule
! 5322: <tt>Gather : Yes;</tt> is associated with an element type, the image of such
! 5323: elements is constructed as a block by the editor: it is never split up.</p>
! 5324: <p>
! 5325: The <tt>Gather</tt> rule may not appear in the <a href="#sectc427">default
! 5326: rules</a>. Elements which do not have the <tt>Gather</tt> rule are considered
! 5327: susceptible to being split up during display. Thus, it is not necessary to
! 5328: use the <tt>Gather : No;</tt> form. This rule must be used prudently and only
! 5329: for those elements which truly need it. If used incorrectly, it can
! 5330: pointlessly increase the size of the image constructed by the editor and lead
! 5331: to excessive memory consumption by the editor.</p>
! 5332: <p>
! 5333: Like the <tt>PageBreak</tt> and <tt>LineBreak</tt> rules, the <tt>Gather</tt>
1.1 cvs 5334: rule can only appear in rules of the primary view and applies to all views
1.18 ! cvs 5335: defined in the presentation schema.</p>
! 5336: <pre> 'Gather' ':' Boolean .</pre>
! 5337: </div>
1.1 cvs 5338:
1.18 ! cvs 5339: <div class="subsection">
1.1 cvs 5340:
1.18 ! cvs 5341: <h3><a name="sectc4224">Visibility</a></h3>
! 5342: <p>
1.1 cvs 5343: The visibility parameter is used to control which elements should or should
5344: not be displayed, based on context. An element can have different
5345: visibilities in different views. If an element's visibility is zero for a
5346: view, that element is not displayed in that view and does not occupy any space
1.18 ! cvs 5347: (its extents are zero).</p>
! 5348: <p>
1.1 cvs 5349: Visibility takes non-negative integer values (positive or zero). If values
5350: greater than 1 are used, they allow the user to choose a degree of visibility
5351: and, thus, to see only those boxes whose visibility parameter exceeds a
5352: certain threshold. This gives the user control over the granularity of the
1.18 ! cvs 5353: displayed pictures.</p>
! 5354: <p>
1.1 cvs 5355: The visibility parameter can be defined as a constant or by inheritance. If
5356: defined by inheritance, it cannot be based on the value of the next or
1.18 ! cvs 5357: previous box. Visibility can only be inherited from above.</p>
! 5358: <p>
1.1 cvs 5359: If it is a numeric attribute's presentation rule, the visibility can be
5360: specified by the attribute's name, in which case the value of the attribute is
1.18 ! cvs 5361: used.</p>
! 5362: <pre> 'Visibility' ':' NumberInherit
1.1 cvs 5363: NumberInherit = Integer / AttrID / Inheritance .
1.18 ! cvs 5364: Integer = NUMBER .</pre>
! 5365: <blockquote class="example">
! 5366: <p>
! 5367: <strong>Example:</strong></p>
! 5368: <p>
! 5369: Suppose that only <tt>Formula</tt> elements should be displayed in the
! 5370: <tt>MathView</tt> view. Then, the default rules should include:</p>
! 5371: <pre>DEFAULT
! 5372: IN MathView Visibility:0;</pre>
! 5373: <p>
! 5374: which makes all elements invisible in the <tt>MathView</tt> view. However,
! 5375: the <tt>Formula</tt> element also has a <tt>Visibility</tt> rule:</p>
! 5376: <pre>Formula :
! 5377: IN MathView Visibility:5;</pre>
! 5378: <p>
! 5379: which makes formulas, and only formulas, visible.</p>
! 5380: </blockquote>
! 5381: </div>
1.1 cvs 5382:
1.18 ! cvs 5383: <div class="subsection">
1.1 cvs 5384:
1.18 ! cvs 5385: <h3><a name="sectc4225">Character style parameters</a></h3>
! 5386: <p>
1.1 cvs 5387: Four parameters are used to determine which characters are used to display
1.18 ! cvs 5388: text. They are size, font, style, and underlining.</p>
1.1 cvs 5389:
1.18 ! cvs 5390: <div class="subsubsection">
1.1 cvs 5391:
1.18 ! cvs 5392: <h4><a name="sectd42251">Character size</a></h4>
! 5393: <p>
1.1 cvs 5394: The size parameter has two effects. First, it is used to specify the actual
1.18 ! cvs 5395: size and distance units for boxes defined in <a href="#sectc4217">relative
! 5396: units</a>. Second, it defines the size of the characters contained in the
! 5397: box.</p>
! 5398: <p>
1.1 cvs 5399: As a distance or length, the size can be expressed in abstract or absolute
5400: units. It can also be inherited. If it is not inherited, it is expressed
1.18 ! cvs 5401: simply as an integer followed by the <tt>pt</tt> keyword, which indicates that
! 5402: the size is expressed in typographer's points. The absence of the <tt>pt</tt>
1.1 cvs 5403: keyword indicates that it is in abstract units in which the value 1 represents
5404: the smallest size while the value 16 is the largest size. The relationship
5405: between these abstract sizes and the real character sizes is controlled by a
5406: table which can be modified statically or even dynamically during the
1.18 ! cvs 5407: execution of the Thot editor.</p>
! 5408: <p>
1.1 cvs 5409: If it is a numeric attribute's presentation rule, the value of the size
5410: parameter can be specified by the attribute's name, in which case the value of
1.18 ! cvs 5411: the attribute is used.</p>
! 5412: <p>
! 5413: <strong>Note:</strong> the only unit available for defining an absolute size
! 5414: is the typographer's point. Centimeters and inches may not be used.</p>
! 5415: <p>
1.1 cvs 5416: If the size is inherited, the rule must specify the relative from which to
5417: inherit and any difference from that relative's value. The difference can be
5418: expressed in either typographer's points or in abstract units. The maximum or
5419: minimum size can also be specified, but without specifying the type of unit:
1.18 ! cvs 5420: it is the same as was specified for the difference.</p>
! 5421: <p>
1.1 cvs 5422: In a numeric attribute's presentation rule, the difference in size can be
5423: indicated by the attribute's name, which means that the attribute's value
5424: should be used as the difference. The attribute can also be used as the
1.18 ! cvs 5425: minimum or maximum size.</p>
! 5426: <pre> 'Size' ':' SizeInherit
1.1 cvs 5427: SizeInherit = SizeAttr [ 'pt' ] /
5428: Kinship InheritedSize .
5429: InheritedSize ='+' SizeAttr [ 'pt' ]
5430: [ 'Max' MaxSizeAttr ] /
5431: '-' SizeAttr [ 'pt' ]
5432: [ 'Min' MinSizeAttr ] /
5433: '=' .
1.6 cvs 5434: SizeAttr = Size / AttrID .
5435: Size = NUMBER .
5436: MaxSizeAttr = MaxSize / AttrID .
5437: MaxSize = NUMBER .
5438: MinSizeAttr = MinSize / AttrID .
1.18 ! cvs 5439: MinSize = NUMBER .</pre>
! 5440: <blockquote class="example">
! 5441: <p>
! 5442: <strong>Example:</strong></p>
! 5443: <p>
! 5444: The rule</p>
! 5445: <pre>Size : Enclosing - 2 pt Min 7;</pre>
! 5446: <p>
! 5447: states that the character size is 2 points less than that of the enclosing
! 5448: box, but that it may not be less than 7 points, whatever the enclosing box's
! 5449: value.</p>
! 5450: <p>
1.1 cvs 5451: The following rules make the text of a report be displayed with medium-sized
5452: characters (for example, size 5), while the title is displayed with larger
1.18 ! cvs 5453: characters and the summary is displayed with smaller characters:</p>
! 5454: <pre>Report :
1.1 cvs 5455: Size : 5;
5456: Title :
5457: Size : Enclosing + 2;
5458: Summary :
1.18 ! cvs 5459: Size : Enclosing - 1;</pre>
! 5460: <p>
! 5461: Thus, the character sizes in the entire document can be changed by changing
! 5462: the size parameter of the Report element, while preserving the relationships
! 5463: between the sizes of the different elements.</p>
! 5464: </blockquote>
! 5465: </div>
! 5466:
! 5467: <div class="subsubsection">
! 5468:
! 5469: <h4><a name="sectd42252">Font and character style</a></h4>
! 5470: <p>
! 5471: The <tt>Font</tt> rule determines the font family to be used to display the
! 5472: characters contained in the box, while the <tt>Style</tt> rule determines
1.1 cvs 5473: their style. Thot recognizes three character fonts (Times, Helvetica, and
5474: Courier) and six styles: Roman, Italics, Bold, BoldItalics, Oblique, and
1.18 ! cvs 5475: BoldOblique.</p>
! 5476: <p>
1.1 cvs 5477: The font family and style can specified by a named constant or can be
5478: inherited. For the name of the font family only the first character is
1.18 ! cvs 5479: used.</p>
! 5480: <p>
1.1 cvs 5481: Only identical inheritance is allowed: the box takes the same font or style as
5482: the box from which it inherits. This is indicated by an equals sign after the
1.18 ! cvs 5483: kinship specification.</p>
! 5484: <blockquote class="example">
! 5485: <p>
! 5486: <strong>Example:</strong></p>
! 5487: <p>
1.3 cvs 5488: To specify that the summary uses the font family of the rest of the document,
1.18 ! cvs 5489: but in the italic style, the following rules are used:</p>
! 5490: <pre>Summary :
1.1 cvs 5491: BEGIN
5492: Font : Enclosing =;
5493: Style : Italics;
1.18 ! cvs 5494: END;</pre>
! 5495: </blockquote>
! 5496: </div>
! 5497:
! 5498: <div class="subsubsection">
! 5499:
! 5500: <h4><a name="sectd42253">Underlining</a></h4>
! 5501: <p>
! 5502: The <tt>Underline</tt> rule is used to specify if the characters contained in
1.1 cvs 5503: a box should have lines drawn on or near them. There are four underlining
1.18 ! cvs 5504: styles: <tt>Underlined</tt>, <tt>Overlined</tt>, <tt>CrossedOut</tt>, and
! 5505: <tt>NoUnderline</tt>. The <tt>Thickness</tt> rule specifies the thickness of
! 5506: the line, <tt>Thin</tt> or <tt>Thick</tt>.</p>
! 5507: <p>
1.1 cvs 5508: As with font family and style, only identical inheritance is allowed: the box
5509: has the same underlining type as the box from which it inherits the value.
1.18 ! cvs 5510: This is indicated by an equals sign after the kinship specification.</p>
! 5511: <pre> 'Underline' ':' UnderLineInherit /
1.1 cvs 5512: 'Thickness' ':' ThicknessInherit /
5513:
5514: UnderLineInherit = Kinship '=' / 'NoUnderline' /
5515: 'Underlined' /
5516: 'Overlined' / 'CrossedOut' .
1.18 ! cvs 5517: ThicknessInherit = Kinship '=' / 'Thick' / 'Thin' .</pre>
! 5518: </div>
! 5519: </div>
! 5520:
! 5521: <div class="subsection">
! 5522:
! 5523: <h3><a name="sectc4226">Stacking order</a></h3>
! 5524: <p>
! 5525: The <tt>Depth</tt> rule is used to define the stacking order of terminal boxes
1.1 cvs 5526: when multiple boxes at least partially overlap. This rule defines how the
5527: depth parameter, which is zero or a positive integer, is calculated. The
5528: depth parameter has a value for all boxes. For terminal boxes in the
5529: structure and for presentation boxes, the depth value is used during display
5530: and printing: the boxes with the lowest value overlap those with higher
5531: depths. For non-terminal boxes, the depth is not interpreted during display,
1.18 ! cvs 5532: but it is used to calculate the depth of terminal boxes by inheritance.</p>
! 5533: <p>
! 5534: Like most other rules, the depth rule is defined in the <a
! 5535: href="#sectc427">default rules</a> of each presentation schema. Thus, there
! 5536: is always a depth value, even when it is not necessary because there is no
! 5537: overlapping. To avoid useless operations, a zero value can be given to the
! 5538: depth parameter, which signifies that overlapping is never a problem.</p>
! 5539: <p>
! 5540: The depth rule has the same form as the <a href="#sectc4224">visibility
! 5541: rule</a>. It can be defined by inheritance or by a constant numeric value.
! 5542: When the rule is attached to a numeric attribute, it can take the value of
! 5543: that attribute.</p>
! 5544: <pre> 'Depth' ':' NumberInherit</pre>
! 5545: <blockquote class="example">
! 5546: <p>
! 5547: <strong>Example:</strong></p>
! 5548: <p>
1.3 cvs 5549: For a purely textual document, in which overlapping never poses a problem, a
1.18 ! cvs 5550: single default <tt>Depth</tt> rule in the presentation schema is
! 5551: sufficient:</p>
! 5552: <pre>DEFAULT
1.1 cvs 5553: Depth : 0;
1.18 ! cvs 5554: ...</pre>
! 5555: <p>
1.1 cvs 5556: To make the text of examples appear on a light blue background, a presentation
1.18 ! cvs 5557: box is defined:</p>
! 5558: <pre>BOXES
1.1 cvs 5559: BlueBG :
5560: BEGIN
5561: Content : Graphics 'R';
5562: Background : LightBlue3;
5563: FillPattern: backgroundcolor;
5564: Depth : 2;
5565: ...
1.18 ! cvs 5566: END;</pre>
! 5567: <p>
! 5568: and is created by the <tt>Example</tt> element, which has the rules:</p>
! 5569: <pre>RULES
1.1 cvs 5570: Example :
5571: BEGIN
5572: CreateFirst (BlueBG);
5573: Depth : 1;
5574: ...
1.18 ! cvs 5575: END;</pre>
! 5576: <p>
! 5577: In this way, the text of an example (if it inherits its depth from its
! 5578: ancestor) will be superimposed on a light blue background, and not the
! 5579: reverse).</p>
! 5580: </blockquote>
! 5581: </div>
! 5582:
! 5583: <div class="subsection">
! 5584:
! 5585: <h3><a name="sectc4227">Line style</a></h3>
! 5586: <p>
! 5587: The <tt>LineStyle</tt> rule determines the style of line which should be used
! 5588: to draw all the elements contained in the box and the box itself, if it has a
! 5589: <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. The line style can be
! 5590: indicated by a name (<tt>Solid</tt>, <tt>Dashed</tt>, <tt>Dotted</tt>) or it
1.13 cvs 5591: can be inherited. All elements of the graphic base type are affected by this
1.1 cvs 5592: rule, but it can be attached to any box and transmitted by inheritance to the
1.18 ! cvs 5593: graphic elements. The border of elements having a <a
! 5594: href="#sectc4230a"><tt>ShowBox</tt> rule</a> is drawn according to the line
! 5595: style specified by this rule.</p>
! 5596: <p>
1.1 cvs 5597: Only identical inheritance is allowed: the box takes the same line style as
5598: the box from which it inherits. This is indicated by an equals sign after the
1.18 ! cvs 5599: kinship specification.</p>
! 5600: <pre> 'LineStyle' ':' LineStyleInherit
1.1 cvs 5601: LineStyleInherit = Kinship '=' /
1.18 ! cvs 5602: 'Solid' / 'Dashed' / 'Dotted' .</pre>
! 5603: <blockquote class="example">
! 5604: <p>
! 5605: <strong>Example:</strong></p>
! 5606: <p>
1.3 cvs 5607: To specify that, in Figures, the graphical parts should be drawn in solid
1.18 ! cvs 5608: lines, the Figure element is given a rule using the <tt>Solid</tt> name:</p>
! 5609: <pre>Figure :
! 5610: LineStyle : Solid;</pre>
! 5611: <p>
! 5612: and the elements composing figures are given an inheritance rule:</p>
! 5613: <pre> LineStyle : Enclosing =;</pre>
! 5614: </blockquote>
! 5615: </div>
! 5616:
! 5617: <div class="subsection">
! 5618:
! 5619: <h3><a name="sectc4228">Line thickness</a></h3>
! 5620: <p>
! 5621: The <tt>LineWeight</tt> rule determines the thickness of the lines of all
1.1 cvs 5622: graphical elements which appear in the box, no matter what their line style.
5623: Line thickness can be specified by a constant value or by inheritance. A
5624: constant value is a positive number followed by an optional unit specification
1.18 ! cvs 5625: (which is absent when using relative units). All available <a
! 5626: href="#sectc4217">distance units</a> can be used. Line thickness is expressed
! 5627: in the same way as <a href="#sectd42221">line spacing</a>.</p>
! 5628: <pre> 'LineWeight' ':' DistOrInherit</pre>
! 5629: <p>
! 5630: All elements of the graphic base type are affected by this rule, but it can be
! 5631: attached to any box and transmitted by inheritance to the graphic elements.
! 5632: The border of element having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>
! 5633: is also drawn according to the thickness specified by this rule.</p>
! 5634: <blockquote class="example">
! 5635: <p>
! 5636: <strong>Example:</strong></p>
! 5637: <p>
! 5638: To specify that, in Figures, the graphical parts should be drawn with lines
! 5639: 0.3 pt thick, the Figure element is given this rule:</p>
! 5640: <pre>Figure :
! 5641: LineWeight : 0.3 pt;</pre>
! 5642: <p>
! 5643: and the elements composing figures are given an inheritance rule:</p>
! 5644: <pre> LineWeight : Enclosing =;</pre>
! 5645: </blockquote>
! 5646: </div>
! 5647:
! 5648: <div class="subsection">
! 5649:
! 5650: <h3><a name="sectc4229">Fill pattern</a></h3>
! 5651: <p>
! 5652: The <tt>FillPattern</tt> rule determines the pattern used to fill closed
1.1 cvs 5653: graphical elements (circles, rectangles, etc.) which appear in the box. This
1.18 ! cvs 5654: rule also specifies the pattern used to fill the box associated with elements
! 5655: having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a><a>. This pattern can
! 5656: be indicated by a named constant or by inheritance. The named constant
! 5657: identifies one of the patterns available in Thot. The names of the available
! 5658: patterns are: nopattern, foregroundcolor, backgroundcolor, gray1, gray2,
! 5659: gray3, gray4, gray5, gray6, gray7, horiz1, horiz2, horiz3, vert1, vert2,
! 5660: vert3, left1, left2, left3, right1, right2, right3, square1, square2, square3,
! 5661: lozenge, brick, tile, sea, basket.</a></p>
! 5662: <p>
! 5663: Like the other rules peculiar to graphics, <tt>LineStyle</tt> and
! 5664: <tt>LineWeight</tt>, only elements of the graphic base type are affected by
! 5665: the <tt>FillPattern</tt> rule, but the rule can be attached to any box and
1.1 cvs 5666: transmitted by inheritance to the graphic elements. As with the other rules
1.18 ! cvs 5667: specific to graphics, only identical inheritance is allowed.</p>
! 5668: <p>
! 5669: The <tt>FillPattern</tt> rule can also be used to determine whether or not
1.12 cvs 5670: text characters, symbols and pictures should be colored. For these element
5671: types (text, symbols, and pictures), the only valid values are
1.18 ! cvs 5672: <tt>nopattern</tt>, <tt>foregroundcolor</tt>, and <tt>backgroundcolor</tt>.
! 5673: When <tt>FillPattern</tt> has the value <tt>backgroundcolor</tt>, text
! 5674: characters, symbols, and bitmaps are given the color specified by the <a
! 5675: href="#sectc4230"><tt>Background</tt> rule</a> which applies to these
! 5676: elements. When <tt>FillPattern</tt> has the value <tt>foregroundcolor</tt>,
! 5677: these same elements are given the color specified by the <a
! 5678: href="#sectc4230"><tt>Foreground</tt> rule</a> which applies to these
! 5679: elements. In all other case, text characters are not colored.</p>
! 5680: <pre> 'FillPattern' ':' NameInherit</pre>
! 5681: <blockquote class="example">
! 5682: <p>
! 5683: <strong>Example:</strong></p>
! 5684: <p>
1.3 cvs 5685: To specify that, in Figures, the closed graphical elements should be filled
5686: with a pattern resembling a brick wall, the Figure element is given this
1.18 ! cvs 5687: rule:</p>
! 5688: <pre>Figure :
! 5689: FillPattern : brick;</pre>
! 5690: <p>
! 5691: and the elements composing figures are given an inheritance rule:</p>
! 5692: <pre> FillPattern : Enclosing =;</pre>
! 5693: </blockquote>
! 5694: </div>
! 5695:
! 5696: <div class="subsection">
! 5697:
! 5698: <h3><a name="sectc4230">Colors</a></h3>
! 5699: <p>
! 5700: The <tt>Foreground</tt> and <tt>Background</tt> rules determine the foreground
1.13 cvs 5701: and background colors of the base elements which appear in the box. They also
1.18 ! cvs 5702: control the color of boxes associated with elements having a <a
! 5703: href="#sectc4230a"><tt>ShowBox</tt> rule</a>. These colors can be specified
! 5704: with a named constant or by inheritance. The named constants specify one of
! 5705: the available colors in Thot. The available color names can be found in the
! 5706: file <tt>thot.color</tt>.</p>
! 5707: <p>
! 5708: The color rules affect the same way all base elements and elements having a <a
! 5709: href="#sectc4230a"><tt>ShowBox</tt> rule</a>, no matter what their type (text,
! 5710: graphics, pictures, symbols). The color rules can be associated with any box
! 5711: and can be transmitted by inheritance to the base elements or the elements
! 5712: having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. Like the preceding
! 5713: rules, only inheritance of the same value is allowed.</p>
! 5714: <pre> 'Foreground' ':' NameInherit
! 5715: 'Background' ':' NameInherit</pre>
! 5716: <p>
! 5717: <strong>Note:</strong> text colors only appear for text elements whose <a
! 5718: href="#sectc4229">fill pattern</a> does not prevent the use of color.</p>
! 5719: <blockquote class="example">
! 5720: <p>
! 5721: <strong>Example:</strong></p>
! 5722: <p>
1.3 cvs 5723: To specify that, in Figures, everything must be drawn in blue on a background
1.18 ! cvs 5724: of yellow, the Figure element is given these rules:</p>
! 5725: <pre>Figure :
1.1 cvs 5726: BEGIN
5727: Foreground : Blue;
5728: Background : Yellow;
5729: Fillpattern : backgroundcolor;
1.18 ! cvs 5730: END;</pre>
! 5731: <p>
! 5732: and the elements composing figures are given inheritance rules:</p>
! 5733: <pre> Foreground : Enclosing =;
1.1 cvs 5734: Background : Enclosing =;
1.18 ! cvs 5735: FillPattern : Enclosing =;</pre>
! 5736: </blockquote>
! 5737: </div>
! 5738:
! 5739: <div class="subsection">
! 5740:
! 5741: <h3><a name="sectc4230a">Background color and border</a></h3>
! 5742: <p>
! 5743: Boxes associated with structural elements are normally not visible, but it is
! 5744: possible to draw their border and/or to paint their area when it is needed.
! 5745: This is achieved by associating the <tt>ShowBox</tt> rule with the concerned
1.13 cvs 5746: element. This rule has no parameter and no value. It is simply written
1.18 ! cvs 5747: <tt>Showbox;</tt>. It is not inherited nor transmitted to any other element.
! 5748: It applies only to the element with which it is associated.</p>
! 5749: <pre> 'ShowBox'</pre>
! 5750: <p>
! 5751: When an element has a <tt>ShowBox</tt> rule, the border is drawn only if the
! 5752: <tt>LineWeight</tt> rule that applies to that element has a non-zero value
! 5753: (this value can be inherited). The color, style and thickness of the border
! 5754: are defined by the <tt>Foreground</tt>, <tt>LineStyle</tt>, and
! 5755: <tt>LineWeight</tt> rules that apply to the element.</p>
! 5756: <p>
! 5757: When an element has a <tt>ShowBox</tt> rule, the background of this element is
! 5758: paint only if the value of the <tt>FillPattern</tt> rule that applies to that
! 5759: element is not <tt>nopattern</tt>. The pattern and color(s) of the background
! 5760: are defined by the <tt>FillPattern</tt>, <tt>Background</tt>, and
! 5761: <tt>Foreground</tt> rules that apply to the element.</p>
! 5762: </div>
! 5763:
! 5764: <div class="subsection">
! 5765:
! 5766: <h3><a name="sectc4230b">Background pictures</a></h3>
! 5767: <p>
! 5768: The <tt>BackgroundPicture</tt> rule allows to display a picture as the
1.13 cvs 5769: background of an element. It has a single parameter, the file name of the
1.18 ! cvs 5770: picture. This is a string delimited by single quotes. If the first character
! 5771: in this string is '/', it is considered as an absolute path, otherwise the
! 5772: file is searched for along the schema directory path. This file may contain a
! 5773: picture in any format accepted by Thot (xbm, xpm, gif, jpeg, png, etc.)</p>
! 5774: <p>
! 5775: The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
1.13 cvs 5776: the element with which they are associated. They are not inherited nor
1.18 ! cvs 5777: transmitted to children elements.</p>
! 5778: <p>
1.13 cvs 5779: The background picture has not always the same size as the element's box.
5780: There are diffrent ways to fill the element box with the picture. This is
1.18 ! cvs 5781: specified by the <tt>PictureMode</tt> rule, which should be associated to the
! 5782: same element. This rule may take one of the following values:</p>
! 5783: <dl>
! 5784: <dt><tt>NormalSize</tt></dt>
! 5785: <dd>
! 5786: The picture is centered in the box, and clipped if it is too large.
! 5787: </dd>
! 5788: <dt><tt>Scale</tt></dt>
! 5789: <dd>
! 5790: The picture is zoomed to fit the box size.
! 5791: </dd>
! 5792: <dt><tt>RepeatX</tt></dt>
! 5793: <dd>
! 5794: The picture is repeated horizontally to fit the box width.
! 5795: </dd>
! 5796: <dt><tt>RepeatY</tt></dt>
! 5797: <dd>
! 5798: The picture is repeated vertically to fit the box height.
! 5799: </dd>
! 5800: <dt><tt>RepeatXY</tt></dt>
! 5801: <dd>
! 5802: The picture is repeated both horizontally and vertically to fill the box.
! 5803: </dd>
! 5804: </dl>
! 5805: <p>
! 5806: If an element has a <tt>BackgroundPicture</tt> rule and no
! 5807: <tt>PictureMode</tt> rule, the <tt>NormalSize</tt> value is assumed.</p>
! 5808: <pre> 'BackgroundPicture' ':' FileName /
1.13 cvs 5809: 'PictureMode' ':' PictMode .
5810:
5811: FileName = STRING .
1.18 ! cvs 5812: PictMode = 'NormalSize' / 'Scale' / 'RepeatXY' / 'RepeatX' / 'RepeatY' .</pre>
! 5813: <p>
! 5814: The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
1.13 cvs 5815: the element with which they are associated. They are not inherited nor
1.18 ! cvs 5816: transmitted to children elements.</p>
! 5817: </div>
1.13 cvs 5818:
1.18 ! cvs 5819: <div class="subsection">
1.1 cvs 5820:
1.18 ! cvs 5821: <h3><a name="sectc4231">Presentation box content</a></h3>
! 5822: <p>
! 5823: The <tt>Content</tt> rule applies to presentation boxes. It indicates the
1.1 cvs 5824: content given to a box. This content is either a variable's value or a
1.18 ! cvs 5825: constant value. In the special case of <a href="#sectc4233">header or footer
! 5826: boxes</a>, the content can also be a structured element type.</p>
! 5827: <p>
1.1 cvs 5828: If the content is a constant, it can be specified, as in a variable
1.18 ! cvs 5829: declaration, either by the name of a constant declared in the <tt>CONST</tt>
1.1 cvs 5830: section or by direct specification of the type and value of the box's
1.18 ! cvs 5831: content.</p>
! 5832: <p>
1.1 cvs 5833: Similarly, if it is a variable, the name of a variable declared in
1.18 ! cvs 5834: <tt>VAR</tt> section can be given or the variable may be defined within
! 5835: parentheses. The content inside the parentheses has the same syntax as a <a
! 5836: href="#sectc426">variable declaration</a>.</p>
! 5837: <p>
1.1 cvs 5838: When the content is a structured element type, the name of the element type is
5839: given after the colon. In this case, the box's content is all elements of
5840: the named type which are designated by references which are part of the page
1.18 ! cvs 5841: on which the header or footer with this <tt>Content</tt> rule appears. Only
! 5842: associated elements can appear in a <tt>Content</tt> rule and the structure
1.1 cvs 5843: must provide references to these elements. Moreover, the box whose content
5844: they are must be a header or footer box generated by a page box of the primary
1.18 ! cvs 5845: view.</p>
! 5846: <pre> 'Content' ':' VarConst
1.1 cvs 5847: VarConst = ConstID / ConstType ConstValue /
5848: VarID / '(' FunctionSeq ')' /
1.18 ! cvs 5849: ElemID .</pre>
! 5850: <p>
! 5851: A presentation box can have only one <tt>Content</tt> rule, which means that
1.1 cvs 5852: the content of a presentation box cannot vary from view to view. However, such
5853: an effect can be achieved by creating several presentation boxes, each with
1.18 ! cvs 5854: different content and visible in different views.</p>
! 5855: <p>
! 5856: The <tt>Content</tt> rule also applies to elements defined as references in
1.1 cvs 5857: the structure schema. In this case, the content defined by the rule must be
5858: a constant. It is this content which appears on the screen or paper to
5859: represent references of the type to which the rule applies. A reference can
1.18 ! cvs 5860: have a <tt>Content</tt> rule or a <a href="#sectc4234"><tt>Copy</tt> rule</a>
1.1 cvs 5861: for each view. If neither of these rules appears, the reference is displayed
1.18 ! cvs 5862: as <tt>[*]</tt>, which is equivalent to the rule:</p>
! 5863: <pre> Content: Text '[*]';</pre>
! 5864: <blockquote class="example">
! 5865: <p>
! 5866: <strong>Example:</strong></p>
! 5867: <p>
1.3 cvs 5868: The content of the presentation box created to make the chapter number and
1.18 ! cvs 5869: section number appear before each section title can be defined by:</p>
! 5870: <pre>BOXES
1.1 cvs 5871: SectionNumBox :
5872: BEGIN
5873: Content : NumSection;
5874: ...
1.18 ! cvs 5875: END;</pre>
! 5876: <p>
! 5877: if the <tt>NumSection</tt> variable has been defined in the variable
! 5878: definition section of the presentation schema. Otherwise the <tt>Content</tt>
! 5879: would be written:</p>
! 5880: <pre>BOXES
1.1 cvs 5881: SectionNumBox :
5882: BEGIN
5883: Content : (VALUE (ChapterCtr, Roman) TEXT '.'
5884: VALUE (SectionCtr, Arabic));
5885: ...
1.18 ! cvs 5886: END;</pre>
! 5887: <p>
! 5888: To specify that a page footer should contain all elements of the <tt>Note</tt>
! 5889: type are referred to in the page, the following rule is written:</p>
! 5890: <pre>BOXES
1.1 cvs 5891: NotesFooterBox :
5892: BEGIN
5893: Content : Note;
5894: ...
1.18 ! cvs 5895: END;</pre>
! 5896: <p>
! 5897: <tt>Note</tt> is defined as an associated element in the structure schema and
! 5898: NotesFooterBox is created by a page box of the primary view.</p>
! 5899: </blockquote>
! 5900: </div>
1.1 cvs 5901:
1.18 ! cvs 5902: <div class="subsection">
1.1 cvs 5903:
1.18 ! cvs 5904: <h3><a name="sectc4232">Presentation box creation</a></h3>
! 5905: <p>
1.1 cvs 5906: A creation rule specifies that a presentation box should be created when an
1.18 ! cvs 5907: element of the type to which the rule is attached appears in the document.</p>
! 5908: <p>
1.1 cvs 5909: A keyword specifies the position, relative to the creating box, at which the
1.18 ! cvs 5910: created box will be placed in the structure:</p>
! 5911: <dl>
! 5912: <dt><tt>CreateFirst</tt></dt>
! 5913: <dd>
! 5914: specifies that the box should be created as the first box of the next lower
1.2 cvs 5915: level, before any already existing boxes, and only if the beginning of the
1.1 cvs 5916: creating element is visible;
1.18 ! cvs 5917: </dd>
! 5918: <dt><tt>CreateLast</tt></dt>
! 5919: <dd>
! 5920: specifies that the box should be created as the last box of the next lower
! 5921: level, after any existing boxes, and only if the end of the creating element
! 5922: is visible;
! 5923: </dd>
! 5924: <dt><tt>CreateBefore</tt></dt>
! 5925: <dd>
! 5926: specifies that the box should be created before the creating box, on the same
! 5927: level as the creating box, and only if the beginning of the creating element
! 5928: is visible;
! 5929: </dd>
! 5930: <dt><tt>CreateAfter</tt></dt>
! 5931: <dd>
! 5932: specifies that the box should be created after the creating box, on the same
! 5933: level as the creating box, and only if the beginning of the creating element
! 5934: is visible;
! 5935: </dd>
! 5936: <dt><tt>CreateEnclosing</tt></dt>
! 5937: <dd>
! 5938: specifies that the box should be created at the upper level relatively to the
! 5939: creating box, and that it must contain that creating box and all presentation
! 5940: boxes created by the same creating box.
! 5941: </dd>
! 5942: </dl>
! 5943: <p>
! 5944: This keyword can be followed by the <tt>Repeated</tt> keyword to indicate that
1.1 cvs 5945: the box must be created for each part of the creating element. These parts
5946: result from the division of the element by page breaks or column changes. If
1.18 ! cvs 5947: the <tt>Repeated</tt> keyword is missing, the box is only created for the
! 5948: first part of the creating element (<tt>CreateFirst</tt> and
! 5949: <tt>CreateBefore</tt> rules) or for the last part (<tt>CreateLast</tt> and
! 5950: <tt>CreateAfter</tt> rules).</p>
! 5951: <p>
1.1 cvs 5952: The type of presentation to be created is specified at the end of the rule
1.18 ! cvs 5953: between parentheses.</p>
! 5954: <p>
! 5955: Creation rules cannot appear in the <a href="#sectc427">default presentation
! 5956: rules</a>. The boxes being created should have a <tt>Content</tt> rule which
! 5957: indicates their <a href="#sectc4231">content</a>.</p>
! 5958: <p>
1.1 cvs 5959: Creation rules can only appear in the block of rules for the primary view;
5960: creation is provoked by a document element for all views. However, for each
5961: view, the presentation box is only created if the creating element is itself a
5962: box in the view. Moreover, the visibility parameter of the presentation box
5963: can be adjusted to control the creation of the box on a view-by-view
1.18 ! cvs 5964: basis.</p>
! 5965: <pre> Creation '(' BoxID ')'
1.1 cvs 5966: Creation = Create [ 'Repeated' ] .
5967: Create ='CreateFirst' / 'CreateLast' /
5968: 'CreateBefore' / 'CreateAfter' /
1.18 ! cvs 5969: 'CreateEnclosing' .</pre>
! 5970: <blockquote class="example">
! 5971: <p>
! 5972: <strong>Example:</strong></p>
! 5973: <p>
1.3 cvs 5974: Let us define an object type, called Table, which is composed of a sequence of
5975: columns, all having the same fixed width, where the columns are separated by
1.18 ! cvs 5976: vertical lines. There is a line to the left of the first column and one to
! 5977: the right of the last. Each column has a variable number of cells, placed one
! 5978: on top of the other and separated by horizontal lines. There are no
! 5979: horizontal lines above the first cell or below the last cell. The text
! 5980: contained in each cell is broken into lines and these lines are centered
! 5981: horizontally in the cell. The logical structure of this object is defined
! 5982: by:</p>
! 5983: <pre>Table = LIST OF (Column);
! 5984: Column = LIST OF (Cell = Text);</pre>
! 5985:
! 5986: <div class="figure">
! 5987: <hr>
! 5988: <pre>| | | |
1.1 cvs 5989: | xx xxxx xxxx |x xxxx xxx xxxxx| x xxx x xxx |
5990: | xxx xxx xxxx x | x xx x xxx | xxxxx xxxx xx |
5991: | xxxxx xxxx |----------------| xxx xxxxx x |
5992: | xxxxx xxx xxxx | xxxx xx xx xxx | xx xx |
5993: | xxx xxxx x xxx | xxxx x xxx x |---------------|
5994: |----------------| xxx xxxx xxxxx | xxxxx xxxxx |
5995: | xxx xxx xxxxxx |----------------| xxx xxxx xxxx |
5996: | xxxx xxxx xx | xxxx xx x xx | xxx xx x xx |
5997: |----------------| xxx xxxxx xxxx | xxxx xxxx xxx |
5998: | xxxxx xxx xxxx | xxxx xx x xx | xxxxx xxx |
1.18 ! cvs 5999: |xxxx xx x xxxxxx| xxxx xx xxxxxx | xxxxx xxxxx |</pre>
! 6000: <p align=center>
! 6001: <em><a name="table">The design of a table</a></em></p>
! 6002: <hr>
! 6003: </div>
! 6004: <p>
! 6005: The presentation of the table should resemble the design of the above <a
! 6006: href="#table">figure</a>. It is defined by the following presentation schema
! 6007: fragment:</p>
! 6008: <pre>BOXES
1.1 cvs 6009: VertLine : BEGIN
6010: Width : 0.3 cm;
6011: Height : Enclosing . Height;
6012: VertPos : Top = Enclosing . Top;
6013: HorizPos : Left = Previous . Right;
6014: Content : Graphics 'v';
6015: END;
6016:
6017: HorizLine: BEGIN
6018: Width : Enclosing . Width;
6019: Height : 0.3 cm;
6020: VertPos : Top = Previous . Bottom;
6021: HorizPos : Left = Enclosing . Left;
6022: Content : Graphics 'h';
6023: END;
6024:
6025: RULES
1.6 cvs 6026: Column : BEGIN
6027: CreateBefore (VertLine);
6028: IF LAST CreateAfter (VertLine);
6029: Width : 2.8 cm;
6030: Height : Enclosed . Height;
6031: VertPos : Top = Enclosing . Top;
6032: HorizPos : Left = Previous . Right;
6033: END;
6034:
6035: Cell : BEGIN
6036: IF NOT FIRST CreateBefore (HorizLine);
6037: Width : Enclosing . Width;
6038: Height : Enclosed . Height;
6039: VertPos : Top = Previous . Bottom;
6040: HorizPos : Left = Enclosing . Left;
6041: Line;
6042: Adjust : VMiddle;
1.18 ! cvs 6043: END;</pre>
! 6044: <p>
1.1 cvs 6045: It is useful to note that the horizontal position rule of the first vertical
6046: line will not be applied, since there is no preceding box. In this case, the
1.18 ! cvs 6047: box is simply placed on the left side of the enclosing box.</p>
! 6048: </blockquote>
! 6049: </div>
! 6050:
! 6051: <div class="subsection">
! 6052:
! 6053: <h3><a name="sectc4233">Page layout</a></h3>
! 6054: <p>
! 6055: The page models specified in the <tt>Page</tt> rule are defined by boxes
! 6056: declared in the <tt>BOXES</tt> section of the presentation schema. Pages are
1.1 cvs 6057: not described as frames which will be filled by the document's text, but as
6058: element are inserted in the flow of the document and which mark the page
6059: breaks. Each of these page break elements contains presentation boxes which
6060: represent the footer boxes of a page followed by header boxes of the next
6061: page. The page box itself is the simple line which separates two pages on the
6062: screen. Both the footer and header boxes placed themselves with respect to
6063: this page box, with the footer being placed above it and the header boxes
1.18 ! cvs 6064: being placed above it.</p>
! 6065: <p>
1.1 cvs 6066: The boxes created by a page box are headers and footers and can only place
6067: themselves vertically with respect to the page box itself (which is in fact
6068: the separation between two pages). Besides, it is their vertical position
6069: rule which determines whether they are header or footer boxes. Header and
6070: footer boxes must have an explicit vertical position rule (they must not use
1.18 ! cvs 6071: the default rule).</p>
! 6072: <p>
1.1 cvs 6073: Footer boxes must have an absolute height or inherit the height of their
1.18 ! cvs 6074: contents:</p>
! 6075: <pre>Height : Enclosed . Height;</pre>
! 6076: <p>
1.1 cvs 6077: A page box must have height and width rules and these two rules must be
6078: specified with constant values, expressed in centimeters, inches, or
6079: typographer's points. These two rules are interpreted in a special way for
6080: page boxes: they determine the width of the page and the vertical distance
6081: between two page separators, which is the height of the page and its header
1.18 ! cvs 6082: and footer together.</p>
! 6083: <p>
1.1 cvs 6084: A page box should also have vertical and horizontal position rules and these
6085: two rules should specify the position on the sheet of paper of the rectangle
6086: enclosing the page's contents. These two rules must position the upper left
6087: corner of the enclosing rectangle in relation to the upper left corner of the
6088: sheet of paper, considered to be the enclosing element. In both rules,
1.18 ! cvs 6089: distances must be expressed in fixed units: centimeters (<tt>cm</tt>), inches
! 6090: (<tt>in</tt>), or typographer's points (<tt>pt</tt>). Thus, rules similar to
! 6091: the following should be found in the rules for a page box:</p>
! 6092: <pre>BOXES
1.1 cvs 6093: ThePage :
6094: BEGIN
6095: VertPos : Top = Enclosing . Top + 3 cm;
6096: HorizPos : Left = Enclosing . Left + 2.5 cm;
6097: Width : 16 cm;
6098: Height : 22.5 cm;
1.18 ! cvs 6099: END;</pre>
! 6100: <p>
1.1 cvs 6101: When a document must be page broken, the page models to be constructed are
1.18 ! cvs 6102: defined in the <tt>BOXES</tt> section of the presentation schema by declaring
! 6103: page boxes and header and footer boxes. Also, the <tt>Page</tt> rule is used
1.1 cvs 6104: to specify to which parts of the document and to which views each model should
1.18 ! cvs 6105: be applied.</p>
! 6106: <p>
! 6107: The <tt>Page</tt> rule has only one parameter, given between parentheses after
! 6108: the <tt>Page</tt> keyword. This parameter is the name of the box which must
! 6109: serve as the model for page construction. When a <tt>Page</tt> rule is
1.1 cvs 6110: attached to an element type, each time such an element appears in a document,
6111: a page break takes place and the page model indicated in the rule is applied
6112: to all following pages, until reaching the next element which has a
1.18 ! cvs 6113: <tt>Page</tt> rule.</p>
! 6114: <p>
! 6115: The <tt>Page</tt> rule applies to only one view; if it appears in the primary
! 6116: view's block of rules, a <tt>Page</tt> rule applies only to that view. Thus,
1.1 cvs 6117: different page models can be defined for the full document and for its table
6118: of contents, which is another view of the same document. Some views can be
6119: specified with pages, and other views of the same document can be specified
1.18 ! cvs 6120: without pages.</p>
! 6121: <pre> 'Page' '(' BoxID ')'</pre>
! 6122: </div>
! 6123:
! 6124: <div class="subsection">
! 6125:
! 6126: <h3><a name="sectc4234">Box copies</a></h3>
! 6127: <p>
! 6128: The <tt>Copy</tt> rule can be used for an element which is defined as a
1.7 cvs 6129: reference in the structure schema. In this case, the rule specifies, between
1.18 ! cvs 6130: parenthesis, the name of the box (declared in the <tt>BOXES</tt> section)
1.1 cvs 6131: which must be produced when this reference appears in the structure of a
6132: document. The box produced is a copy (same contents, but possible different
6133: presentation) of the box type indicated by the parameter between parentheses,
6134: and which is in the element designated by the reference. The name of a box
6135: can be replaced by type name. Then what is copied is the contents of the
1.18 ! cvs 6136: element of this type which is inside the referenced element.</p>
! 6137: <p>
1.1 cvs 6138: Whether a box name or type name is given, it may be followed by the name of a
6139: structure schema between parentheses. This signifies that the box or type is
6140: defined in the indicated structure schema and not in the structure schema with
1.18 ! cvs 6141: which the rule's presentation schema is associated.</p>
! 6142: <p>
! 6143: The <tt>Copy</tt> rule can also be applied to a presentation box. If the
1.1 cvs 6144: presentation box was created by a reference attribute, the rule is applied as
6145: in the case of a reference element: the contents of the box having the
1.18 ! cvs 6146: <tt>Copy</tt> rule are based on the element designated by the reference
! 6147: attribute. For other presentation boxes, the <tt>Copy</tt> rule takes a type
1.1 cvs 6148: name parameter which can be followed, between parentheses, by the name of the
6149: structure schema in which the type is defined, if it is not defined in the
6150: same schema. The contents of the box which has this rule are a copy of the
6151: element of this type which is in the element creating the presentation box, or
6152: by default, the box of this type which precedes the presentation box. This
6153: last facility is used, for example, to define the running titles in headers or
1.18 ! cvs 6154: footers.</p>
! 6155: <pre> 'Copy' '(' BoxTypeToCopy ')' .
1.1 cvs 6156: BoxTypeToCopy = BoxID [ ExtStruct ] /
1.6 cvs 6157: ElemID [ ExtStruct ] .
1.18 ! cvs 6158: ExtStruct = '(' ElemID ')' .</pre>
! 6159: <p>
! 6160: Like the creation rules, the <tt>Copy</tt> rule cannot appear in the <a
! 6161: href="#sectc427">default presentation rules</a>. Moreover, this rule can only
! 6162: appear in the primary view's block of rules; the copy rule is applied to all
! 6163: views.</p>
! 6164: <blockquote class="example">
! 6165: <p>
! 6166: <strong>Example:</strong></p>
! 6167: <p>
! 6168: If the following definitions are in the structure schema:</p>
! 6169: <pre>Body = LIST OF (Chapter =
1.1 cvs 6170: BEGIN
6171: ChapterTitle = Text;
6172: ChapterBody = SectionSeq;
6173: END);
1.18 ! cvs 6174: RefChapter = REFERENCE (Chapter);</pre>
! 6175: <p>
! 6176: then the following presentation rules (among many other rules in the
! 6177: presentation schema) can be specified:</p>
! 6178: <pre>COUNTERS
1.1 cvs 6179: ChapterCtr : RANK OF Chapter;
6180: BOXES
6181: ChapterNumber :
6182: BEGIN
6183: Content : (VALUE (ChapterCtr, URoman));
6184: ...
6185: END;
6186: RULES
6187: Chapter :
6188: BEGIN
6189: CreateFirst (ChapterNumber);
6190: ...
6191: END;
6192: RefChapter :
6193: BEGIN
6194: Copy (ChapterNumber);
6195: ...
1.18 ! cvs 6196: END;</pre>
! 6197: <p>
1.4 cvs 6198: which makes the number of the chapter designated by the reference appear in
6199: uppercase roman numerals, in place of the reference to a chapter itself.
6200: Alternatively, the chapter title can be made to appear in place of the
1.18 ! cvs 6201: reference by writing this <tt>Copy</tt>rule:</p>
! 6202: <pre> Copy (ChapterTitle);</pre>
! 6203: <p>
! 6204: To define a header box, named <tt>RunningTitle</tt>, which contains the title
! 6205: of the current chapter, the box's contents are defined in this way:</p>
! 6206: <pre>BOXES
1.1 cvs 6207: RunningTitle :
1.18 ! cvs 6208: Copy (ChapterTitle);</pre>
! 6209: </blockquote>
! 6210: </div>
! 6211: </div>
! 6212: <hr>
! 6213: </div>
1.1 cvs 6214:
1.18 ! cvs 6215: <div class="chapter">
1.1 cvs 6216:
1.18 ! cvs 6217: <h1><a name="sect5">The T language</a></h1>
1.1 cvs 6218:
1.18 ! cvs 6219: <div class="section">
1.1 cvs 6220:
1.18 ! cvs 6221: <h2><a name="sectb51">Document translation</a></h2>
! 6222: <p>
1.1 cvs 6223: Because of its document model, Thot can produce documents in a high-level
1.18 ! cvs 6224: abstract form. This form, called the <em>canonical form</em> is specific to
1.1 cvs 6225: Thot; it is well suited to the editor's manipulations, but it does not
6226: necessarily suit other operations which might be applied to documents. Because
6227: of this, the Thot editor offers the choice of saving documents in its own form
6228: (the canonical form) or a format defined by the user. In the latter case, the
6229: Thot document is transformed by the translation program. This facility can
6230: also be used to export documents from Thot to systems using other
1.18 ! cvs 6231: formalisms.</p>
1.1 cvs 6232:
1.18 ! cvs 6233: <div class="subsection">
1.1 cvs 6234:
1.18 ! cvs 6235: <h3><a name="sectc511">Translation principles</a></h3>
! 6236: <p>
1.1 cvs 6237: Document translation allows the export of documents to other systems which do
6238: not accept Thot's canonical form. Translation can be used to export document
1.18 ! cvs 6239: to source-based formatters like T<sub><big>E</big></sub>X,
! 6240: L<sup>A</sup>T<sub><big>E</big></sub>X, and <tt>troff</tt>. It can also be
1.1 cvs 6241: used to translate documents into interchange formats like SGML or HTML. To
6242: allow the widest range of possible exports, Thot does not limit the choice of
6243: translations, but rather allows the user to define the formalisms into which
1.18 ! cvs 6244: documents can be translated.</p>
! 6245: <p>
1.1 cvs 6246: For each document or object class, a set of translation rules can be defined,
6247: specifying how the canonical form should be transformed into a given
1.18 ! cvs 6248: formalism. These translation rules are grouped into <em>translation
! 6249: schemas</em>, each schema containing the rules necessary to translate a
1.1 cvs 6250: generic logical structure (document or object structure) into a particular
6251: formalism. The same generic logical structure can have several different
6252: translation schemas, each defining translation rules for a different
1.18 ! cvs 6253: formalism.</p>
! 6254: <p>
1.1 cvs 6255: Like presentation schemas, translation schemas are generic. Thus, they apply
6256: to an entire object or document class and permit translation of all documents
1.18 ! cvs 6257: or objects of that class.</p>
! 6258: </div>
1.1 cvs 6259:
1.18 ! cvs 6260: <div class="subsection">
1.1 cvs 6261:
1.18 ! cvs 6262: <h3><a name="sectc512">Translation procedure</a></h3>
! 6263: <p>
1.1 cvs 6264: The translator works on the specific logical structure of the document being
6265: translated. It traverses the primary tree of this logical structure in
6266: pre-order and, at each node encountered, it applies the corresponding
6267: translation rules defined in the translation schema. Translation can be
1.18 ! cvs 6268: associated:</p>
! 6269: <ul>
! 6270: <li>
! 6271: with element types defined in the structure schema,
! 6272: <li>
! 6273: with global or local attributes defined in the structure schema,
! 6274: <li>
! 6275: with specific presentation rules,
! 6276: <li>
! 6277: with the content of the leaves of the structure (characters, symbols and
1.1 cvs 6278: graphical elements)
1.18 ! cvs 6279: </ul>
! 6280: <p>
1.1 cvs 6281: Thus, for each node, the translator applies all rules associated with the
6282: element type, all rules associated with each attribute (local or global)
6283: carried by the element, and if the element is a leaf of the tree, it also
1.10 cvs 6284: applies translation rules for characters, symbols, or graphical elements,
1.18 ! cvs 6285: depending on the type of the leaf.</p>
! 6286: <p>
1.1 cvs 6287: Rules associated with the content of leaves are different from all other
6288: rules: they specify only how to translate character strings, symbols, and
6289: graphical elements. All other rules, whether associated with element types,
6290: with specific presentation rules or with attributes, are treated similarly.
1.18 ! cvs 6291: These rules primarily allow:</p>
! 6292: <ul>
! 6293: <li>
! 6294: generation of a text constant or variable before or after the contents of an
! 6295: element,
! 6296: <li>
! 6297: modification of the order in which elements appear after translation,
! 6298: <li>
! 6299: removal of an element in the translated document,
! 6300: <li>
! 6301: and writing messages on the user's terminal during translation.
! 6302: </ul>
! 6303: </div>
! 6304: </div>
1.1 cvs 6305:
1.18 ! cvs 6306: <div class="section">
1.1 cvs 6307:
1.18 ! cvs 6308: <h2><a name="sectb52">Translation definition language</a></h2>
! 6309: <p>
1.1 cvs 6310: Translation schemas are written in a custom language, called T, which is
6311: described in the rest of this chapter. The grammar of T is specified using
1.18 ! cvs 6312: the same <a href="#sectc321">meta-language</a> as was used for the S and P
1.1 cvs 6313: languages and the translation schemas are written using the same conventions
6314: as the structure and presentation schemas. In particular, the keywords of the
6315: T language (the stings between apostrophes in the following syntax rules) can
6316: be written in any combination of upper-case and lower-case letters, but
6317: identifiers created by the programmer must always be written in the same
1.18 ! cvs 6318: way.</p>
1.1 cvs 6319:
1.18 ! cvs 6320: <div class="subsection">
1.1 cvs 6321:
1.18 ! cvs 6322: <h3><a name="sectc521">Organization of a translation schema</a></h3>
! 6323: <p>
! 6324: A translation schema is begun by the <tt>TRANSLATION</tt> keyword and is
! 6325: terminated by the <tt>END</tt> keyword. The <tt>TRANSLATION</tt> keyword is
1.1 cvs 6326: followed by the name of the generic structure for which a translation is being
6327: defined and a semicolon. This name must be identical to the name which
1.18 ! cvs 6328: appears after the <tt>STRUCTURE</tt> keyword in the corresponding structure
! 6329: schema.</p>
! 6330: <p>
1.1 cvs 6331: After this declaration of the structure, the following material appears in
1.18 ! cvs 6332: order:</p>
! 6333: <ul>
! 6334: <li>
! 6335: the length of lines produced by the translation,
! 6336: <li>
! 6337: the character delimiting the end of the line,
! 6338: <li>
! 6339: the character string which the translator will insert if it must line-break
! 6340: the translated text,
! 6341: <li>
! 6342: declarations of
! 6343: <ul>
! 6344: <li>
! 6345: buffers,
! 6346: <li>
! 6347: counters,
! 6348: <li>
! 6349: constants,
! 6350: <li>
! 6351: variables,
! 6352: </ul>
! 6353: <li>
! 6354: translation rules associated with element types,
! 6355: <li>
! 6356: translation rules associated with attributes,
! 6357: <li>
! 6358: translation rules associated with specific presentation rules,
! 6359: <li>
! 6360: translation rules associated with characters strings, symbols and graphical
! 6361: elements.
! 6362: </ul>
! 6363: <p>
1.1 cvs 6364: Each of these sections is introduced by a keyword followed by a sequence of
6365: declarations. All of these sections are optional, expect for the translation
1.18 ! cvs 6366: rules associated with element types. Many <tt>TEXTTRANSLATE</tt> sections can
1.1 cvs 6367: appear, each defining the rules for translating character strings of a
1.18 ! cvs 6368: particular alphabet.</p>
! 6369: <pre> TransSchema ='TRANSLATION' ElemID ';'
1.1 cvs 6370: [ 'LINELENGTH' LineLength ';' ]
6371: [ 'LINEEND' CHARACTER ';' ]
6372: [ 'LINEENDINSERT' STRING ';' ]
6373: [ 'BUFFERS' BufferSeq ]
6374: [ 'COUNTERS' CounterSeq ]
6375: [ 'CONST' ConstSeq ]
6376: [ 'VAR' VariableSeq ]
6377: 'RULES' ElemSeq
6378: [ 'ATTRIBUTES' AttrSeq ]
6379: [ 'PRESENTATION' PresSeq ]
6380: < 'TEXTTRANSLATE' TextTransSeq >
6381: [ 'SYMBTRANSLATE' TransSeq ]
6382: [ 'GRAPHTRANSLATE' TransSeq ]
1.18 ! cvs 6383: 'END' .</pre>
! 6384: </div>
1.1 cvs 6385:
1.18 ! cvs 6386: <div class="subsection">
1.1 cvs 6387:
1.18 ! cvs 6388: <h3><a name="sectc522">Line length</a></h3>
! 6389: <p>
! 6390: If a <tt>LINELENGTH</tt> instruction is present after the structure
1.1 cvs 6391: declaration, the translator divides the text it produces into lines, each line
6392: having a length less than or equal to the integer which follows the
1.18 ! cvs 6393: <tt>LINELENGTH</tt> keyword. This maximum line length is expressed as a
1.1 cvs 6394: number of characters. The end of the line is marked by the character defined
1.18 ! cvs 6395: by the <tt>LINEEND</tt> instruction. When the translator breaks the lines on
1.1 cvs 6396: a space character in generated text, this space will be replaced by the
1.18 ! cvs 6397: character string defined by the <tt>LINEENDINSERT</tt> instruction.</p>
! 6398: <p>
! 6399: If the <tt>LINEEND</tt> instruction is not defined then the linefeed character
1.1 cvs 6400: (octal code 12) is used as the default line end character. If the
1.18 ! cvs 6401: <tt>LINEENDINSERT</tt> instruction is not defined, the linefeed character is
! 6402: inserted at the end of the produced lines. If there is no <tt>LINELENGTH</tt>
1.1 cvs 6403: instruction, the translated text is not divided into lines. Otherwise, if the
6404: translation rules generate line end marks, these marks remain in the
6405: translated text, but the length of the lines is not controlled by the
1.18 ! cvs 6406: translator.</p>
! 6407: <pre> LineLength = NUMBER .</pre>
! 6408: <blockquote class="example">
! 6409: <p>
! 6410: <strong>Example:</strong></p>
! 6411: <p>
! 6412: To limit the lines produced by the translator to a length of 80 characters,
! 6413: the following rule is written at the beginning of the translation schema.</p>
! 6414: <pre>LineLength 80;</pre>
! 6415: </blockquote>
! 6416: </div>
1.1 cvs 6417:
1.18 ! cvs 6418: <div class="subsection">
1.1 cvs 6419:
1.18 ! cvs 6420: <h3><a name="sectc523">Buffers</a></h3>
! 6421: <p>
1.1 cvs 6422: A buffer is a unit of memory managed by the translator, which can either
1.18 ! cvs 6423: contain text read from the terminal during the translation (see the <a
! 6424: href="#sectc5212"><tt>Read</tt> rule</a>), or the name of the last picture
1.1 cvs 6425: (bit-map) encountered by the translator in its traversal of the document.
1.2 cvs 6426: Remember the pictures are stored in files that are separate for the document
1.1 cvs 6427: files and that the canonical form contains only the names of the files in
1.18 ! cvs 6428: which the pictures are found.</p>
! 6429: <p>
1.1 cvs 6430: Thus, there are two types of buffers: buffers for reading from the terminal
1.18 ! cvs 6431: (filled by the <tt>Read</tt> rule) and the buffer of picture names (containing
1.2 cvs 6432: the name of the last picture encountered). A translation schema can use
6433: either type, one or several read buffers and one (and only one) picture name
1.18 ! cvs 6434: buffer.</p>
! 6435: <p>
! 6436: If any buffers are used, the <tt>BUFFERS</tt> keyword must be present,
1.1 cvs 6437: followed by declarations of every buffer used in the translation schema. Each
6438: buffer declaration is composed only of the name of the buffer, chosen freely
1.2 cvs 6439: by the programmer. The picture name buffer is identified by the
1.18 ! cvs 6440: <tt>Picture</tt> keyword, between parentheses, following the buffer name. The
! 6441: <tt>Picture</tt> keyword may only appear once. Each buffer declaration is
! 6442: terminated by a semicolon.</p>
! 6443: <pre> BufferSeq = Buffer < Buffer > .
1.1 cvs 6444: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
1.18 ! cvs 6445: BufferID = NAME .</pre>
! 6446: <blockquote class="example">
! 6447: <p>
! 6448: <strong>Example:</strong></p>
! 6449: <p>
1.3 cvs 6450: The following buffer declarations create a picture name buffer named
1.18 ! cvs 6451: <tt>pictureName</tt> and a read buffer named <a
! 6452: name="destname"><tt>DestName</tt></a>:</p>
! 6453: <pre>BUFFERS
! 6454: pictureName (Picture); DestName;</pre>
! 6455: </blockquote>
! 6456: </div>
1.1 cvs 6457:
1.18 ! cvs 6458: <div class="subsection">
1.1 cvs 6459:
1.18 ! cvs 6460: <h3><a name="sectc524">Counters</a></h3>
! 6461: <p>
1.1 cvs 6462: Certain translation rules generate text that varies according to the context
6463: of the element to which the rules apply. Variable text is defined either in
1.18 ! cvs 6464: the <a href="#sectc526"><tt>VAR</tt> section</a> of the translation schema or
! 6465: in the rule itself (see the <tt>Create</tt> and <tt>Write</tt> rules). Both
1.1 cvs 6466: types of definition rely on counters for the calculation of variable
1.18 ! cvs 6467: material.</p>
! 6468: <p>
1.1 cvs 6469: There are two types of counter: counters whose value is explicitely computed
1.18 ! cvs 6470: by applying <a href="#sectc5221"><tt>Set</tt> and <tt>Add</tt> rules</a>, and
1.1 cvs 6471: counters whose value is computed by a function associated with the counter.
6472: Those functions allow the same calculations as can be used in presentation
6473: schemas. As in a presentation schema, counters must be defined in the
1.18 ! cvs 6474: <tt>COUNTERS</tt> section of the translation schema before they are used.</p>
! 6475: <p>
! 6476: When counters are used in a translation schema, the <tt>COUNTERS</tt> keyword
1.1 cvs 6477: is followed by the declarations of every counter used. Each declaration is
6478: composed of the counter's name possibly followed by a colon and the counting
6479: function to be used for the counter. The declaration is terminated by a
1.18 ! cvs 6480: semi-colon. If the counter is explicitely computed by <tt>Set</tt> and
! 6481: <tt>Add</tt> rules, no counting function is indicated. If a counting function
! 6482: is indicated, <tt>Set</tt> and <tt>Add</tt> rules cannot be applied to that
! 6483: counter.</p>
! 6484: <p>
1.1 cvs 6485: The counting function indicates how the counter's value will be computed.
1.18 ! cvs 6486: Three functions are available: <tt>Rank</tt>, <tt>Rlevel</tt>, and
! 6487: <tt>Set</tt>.</p>
! 6488: <ul>
! 6489: <li>
! 6490: <tt>Rank of ElemID</tt> indicates that the counter's value is the rank of the
! 6491: element of type <tt>ElemID</tt> which encloses the element for which the
1.2 cvs 6492: counter is being evaluated. For the purposes of this function, an element of
1.18 ! cvs 6493: type <tt>ElemID</tt> is considered to enclose itself. This function is
! 6494: primarily used when the element of type <tt>ElemID</tt> is part of an
1.2 cvs 6495: aggregate or list, in which case the counter's value is the element's rank in
1.18 ! cvs 6496: its list or aggregate. Note that, unlike the <tt>Rank</tt> function for
! 6497: presentation schemas, the <tt>Page</tt> keyword cannot be used in place of the
! 6498: <tt>ElemID</tt>.
! 6499: <p>
! 6500: The type name <tt>ElemID</tt> can be followed by an integer. That number
1.1 cvs 6501: represents the relative level, among the ancestors of the concerned element,
1.18 ! cvs 6502: of the element whose rank is asked. If that relative level <i>n</i> is
! 6503: unsigned, the <i>n<sup>th</sup></i> element of type <tt>ElemID</tt>
! 6504: encountered when travelling the logical structure from the root to the
! 6505: concerned element is taken into account. If the relative level is negative,
! 6506: the logical structure is travelled in the other direction, from the concerned
! 6507: element to the root.</p>
! 6508: <li>
! 6509: <tt>Rlevel of ElemID</tt> indicates that the counter's values is the relative
! 6510: level in the tree of the element for which the counter is being evaluated. The
! 6511: counter counts the number of elements of type <tt>ElemID</tt> which are found
! 6512: on the path between the root of the document's logical structure tree and the
! 6513: element (inclusive).
! 6514: <li>
! 6515: <tt>Set n on Type1 Add m on Type2</tt> indicates that the counter's value is
! 6516: calculated as follows: in traversing the document from the beginning to the
! 6517: element for which the counter is being evaluated, the counter is set to the
! 6518: value <tt>n</tt> each time a <tt>Type1</tt> element is encountered and is
! 6519: incremented by the amount <tt>m</tt> each time a <tt>Type2</tt> element is
! 6520: encountered. The initial value <tt>n</tt> and the increment <tt>m</tt> are
1.1 cvs 6521: integers.
1.18 ! cvs 6522: </ul>
! 6523: <p>
! 6524: As in a presentation schema, the <tt>Rank</tt> and <tt>Set</tt> functions can
1.1 cvs 6525: be modified by a numeric attribute which changes their initial value. This is
1.18 ! cvs 6526: indicated by the <tt>Init</tt> keyword followed by the numeric attribute's
! 6527: name. The <tt>Set</tt> function takes the value of the attribute instead of
! 6528: the <tt>InitValue</tt> (<tt>n</tt>). For the <tt>Rank</tt> function, the
1.1 cvs 6529: value of the attribute is considered to be the rank of the first element of
6530: the list (rather than the normal value of 1). Subsequent items in the list
6531: have their ranks shifted accordingly. In both cases, the attribute must be
1.18 ! cvs 6532: numeric and must be a local attribute of the root of the document itself.</p>
! 6533: <pre> CounterSeq = Counter < Counter > .
1.1 cvs 6534: Counter = CounterID [ ':' CounterFunc ] ';' .
6535: CounterID = NAME .
6536: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
6537: [ 'Init' AttrID ] /
6538: 'Rlevel' 'of' ElemID /
6539: 'Set' InitValue 'On' ElemID
6540: 'Add' Increment 'On' ElemID
6541: [ 'Init' AttrID ] .
6542: SLevelAsc = [ '-' ] LevelAsc .
6543: LevelAsc = NUMBER .
6544: InitValue = NUMBER .
6545: Increment = NUMBER .
6546: ElemID = NAME .
1.18 ! cvs 6547: AttrID = NAME .</pre>
! 6548: <blockquote class="example">
! 6549: <p>
! 6550: <strong>Example:</strong></p>
! 6551: <p>
! 6552: If the body of a chapter is defined in the structure schema by:</p>
! 6553: <pre>Chapter_Body = LIST OF
1.1 cvs 6554: (Section = BEGIN
6555: Section_Title = Text;
6556: Section_Body = BEGIN
6557: Paragraphs;
6558: Section;
6559: END;
6560: END
1.18 ! cvs 6561: );</pre>
! 6562: <p>
! 6563: (sections are defined recursively), a counter can be defined giving the <a
! 6564: name="sectnum">number of a section</a> within its level in the hierarchy:</p>
! 6565: <pre>COUNTERS
! 6566: SectionNumber : Rank of Section;</pre>
! 6567: <p>
! 6568: A counter holding the hierarchic level of a section:</p>
! 6569: <pre> SectionLevel : Rlevel of Section;</pre>
! 6570: <p>
! 6571: A <a name="uniquenum">counter</a> which sequentially numbers all the
! 6572: document's sections, whatever their hierarchic level:</p>
! 6573: <pre> UniqueSectNum : Set 0 on Document Add 1 on Section;</pre>
! 6574: </blockquote>
! 6575: </div>
1.1 cvs 6576:
1.18 ! cvs 6577: <div class="subsection">
1.1 cvs 6578:
1.18 ! cvs 6579: <h3><a name="sectc525">Constants</a></h3>
! 6580: <p>
1.1 cvs 6581: A common feature of translation rules is the generation of constant text. This
1.18 ! cvs 6582: text can be defined in the rule that generates it (see for example the <a
! 6583: href="#sectc5210"><tt>Create</tt></a> and <a
! 6584: href="#sectc5211"><tt>Write</tt></a> rules); but it can also be defined once
! 6585: in the constant declaration section and used many times in different rules.
! 6586: The latter option is preferable when the same text is used in several rules or
! 6587: several <a href="#sectc526">variables</a>.</p>
! 6588: <p>
! 6589: The <tt>CONST</tt> keyword begins the constant declaration section of the
1.1 cvs 6590: translation schema. It must be omitted if no constants are declared. Each
6591: constant declaration is composed of the constant name, an equals sign, and the
6592: constant's value, which is a character string between apostrophes. A constant
1.18 ! cvs 6593: declaration is terminated by a semicolon.</p>
! 6594: <pre> ConstSeq = Const < Const > .
1.1 cvs 6595: Const = ConstID '=' ConstValue ';' .
6596: ConstID = NAME .
1.18 ! cvs 6597: ConstValue = STRING .</pre>
! 6598: <blockquote class="example">
! 6599: <p>
! 6600: <strong><a name="levelexample">Example:</a></strong></p>
! 6601: <p>
! 6602: The following rule assigns the name <tt>TxtLevel</tt> to the character string
! 6603: ``Level'':</p>
! 6604: <pre>CONST
! 6605: TxtLevel = 'Level';</pre>
! 6606: </blockquote>
! 6607: </div>
1.1 cvs 6608:
1.18 ! cvs 6609: <div class="subsection">
1.1 cvs 6610:
1.18 ! cvs 6611: <h3><a name="sectc526">Variables</a></h3>
! 6612: <p>
1.10 cvs 6613: Variables allow to define variable text which is generated by the
1.18 ! cvs 6614: <tt>Create</tt> and <tt>Write</tt> rules. They are also used to define file
! 6615: names which are used in the <tt>Create</tt>, <tt>ChangeMainFile</tt>,
! 6616: <tt>RemoveFile</tt>, and <tt>Indent</tt> rules. Variables can be defined
! 6617: either in the <tt>VAR</tt> section of the translation schema or directly in
! 6618: the rules which use them. Variables that define file names must be declared
! 6619: in the <tt>VAR</tt> section, and when the same variable is used several times
! 6620: in the translation schema, it makes sense to define it globally in the
! 6621: <tt>VAR</tt> section. This section is only present if at least one variable
! 6622: is defined globally.</p>
! 6623: <p>
! 6624: After the <tt>VAR</tt> keyword, each global variable is defined by its name, a
1.1 cvs 6625: colon separator and a sequence of functions (at least one function). Each
6626: variable definition is terminated by a semicolon. Functions determine the
6627: different parts which together give the value of the variable. The value is
6628: obtained by concatenating the strings produced by each of the functions. Seven
6629: types of functions are available. Each variable definition may use any number
1.18 ! cvs 6630: of functions of each type.</p>
! 6631: <ul>
! 6632: <li>
! 6633: The function <tt>Value(Counter)</tt>returns a string representing the value
! 6634: taken by the counter when it is evaluated for the element in whose rule the
! 6635: variable is used. The counter must have been declared in the
! 6636: <tt>COUNTERS</tt> section of the translation schema. When the counter is
1.2 cvs 6637: expressed in arabic numerals, the counter name can be followed by a colon and
6638: an integer indicating a minimum length (number of characters) for the string;
6639: if the counter's value is normally expressed with fewer characters than the
6640: required minimum, zeroes are added to the front of the string to achieve the
1.5 cvs 6641: minimum length.
1.18 ! cvs 6642: <p>
1.1 cvs 6643: By default, the counter value is written in arabic digits. If another
6644: representation of that value is needed, the counter name must be followed by a
1.18 ! cvs 6645: comma and one of the following keywords:</p>
! 6646: <ul>
! 6647: <li>
! 6648: <tt>Arabic</tt>: arabic numerals (default value),
! 6649: <li>
! 6650: <tt>LRoman</tt>: lower-case roman numerals,
! 6651: <li>
! 6652: <tt>URoman</tt>: upper-case roman numerals,
! 6653: <li>
! 6654: <tt>Uppercase</tt>: upper-case letter,
! 6655: <li>
! 6656: <tt>Lowercase</tt>: lower-case letter.
! 6657: </ul>
! 6658: <li>
! 6659: The function <tt>FileDir</tt>, without parameter, returns a string
1.2 cvs 6660: representing the name of the directory of the output file that has been given
6661: as a parameter to the translation program. The string includes a character '/'
6662: at the end.
1.18 ! cvs 6663: <li>
! 6664: The function <tt>FileName</tt>, without parameter, returns a string
1.2 cvs 6665: representing the name of the output file that has been given as a parameter to
6666: the translation program. The file extension (the character string that
6667: terminate the file name, after a dot) is not part of that string.
1.18 ! cvs 6668: <li>
! 6669: The function <tt>Extension</tt>, without parameter, returns a string
1.2 cvs 6670: representing the extension of the file name. That string is empty if the file
6671: name that has been given as a parameter to the translation program has no
6672: extension. If there is an extension, its first character is a dot.
1.18 ! cvs 6673: <li>
! 6674: The function <tt>DocumentName</tt>, without parameter, returns a string
1.2 cvs 6675: representing the name of the document being translated.
1.18 ! cvs 6676: <li>
! 6677: The function <tt>DocumentDir</tt>, without parameter, returns a string
1.2 cvs 6678: representing the directory containing the document being translated.
1.18 ! cvs 6679: <li>
! 6680: The function formed by the name of a constant returns that constant's value.
! 6681: <li>
! 6682: The function formed by a character string between apostrophes returns that
1.1 cvs 6683: string.
1.18 ! cvs 6684: <li>
! 6685: The function formed by the name of a buffer returns the contents of that
1.2 cvs 6686: buffer. If the named buffer is the picture buffer, then the name of the last
6687: picture encountered is returned. Otherwise, the buffer is a read buffer and
6688: the value returned is text previously read from the terminal. If the buffer
1.18 ! cvs 6689: is empty (no picture has been encountered or the <tt>Read</tt> rule has not
1.2 cvs 6690: been executed for the buffer), then the empty string is returned.
1.18 ! cvs 6691: <li>
! 6692: The function formed by an attribute name takes the value of the indicated
1.2 cvs 6693: attribute for the element to which the variable applies. If the element does
6694: not have that attribute, then the element's ancestor are searched toward the
6695: root of the tree. If one of the ancestors does have the attribute then its
6696: value is used. If no ancestors have the attribute, then the value of the
1.1 cvs 6697: function is the empty string.
1.18 ! cvs 6698: </ul>
! 6699: <pre> VariableSeq = Variable < Variable > .
1.1 cvs 6700: Variable = VarID ':' Function < Function > ';' .
6701: VarID = NAME .
6702: Function ='Value' '(' CounterID [ ':' Length ]
6703: [ ',' CounterStyle ] ')' /
6704: 'FileDir' / 'FileName' / 'Extension' /
6705: 'DocumentName' / 'DocumentDir' /
6706: ConstID / CharString /
6707: BufferID / AttrID .
6708: Length = NUMBER .
6709: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
6710: 'Uppercase' / 'Lowercase' .
1.18 ! cvs 6711: CharString = STRING .</pre>
! 6712: <blockquote class="example">
! 6713: <p>
! 6714: <strong>Example:</strong></p>
! 6715: <p>
1.3 cvs 6716: To create, at the beginning of each section of the translated document, text
6717: composed of the string ``Section'' followed by the section number, the
1.18 ! cvs 6718: following <a name="varsectexample">variable definition</a> might be used:</p>
! 6719: <pre>VAR
! 6720: SectionVar : 'Section' Value(SectionNumber);</pre>
! 6721: <p>
! 6722: (see the definition of <a href="#sectnum"><tt>SectionNumber</tt></a>).</p>
! 6723: <p>
1.1 cvs 6724: The following variable definition can be used to create, at the beginning of
6725: each section, the text ``Level'' followed by the hierarchical level of the
1.18 ! cvs 6726: section. It used the constant defined above.</p>
! 6727: <pre> LevelVar : TxtLevel Value(SectionLevel);</pre>
! 6728: <p>
! 6729: (see the definitions of <a href="#sectnum"><tt>SectionLevel</tt></a> and of <a
! 6730: href="#levelexample"><tt>TxtLevel</tt></a>).</p>
! 6731: <p>
! 6732: To generate the translation of each section in a different file (see <a
! 6733: href="#sectc5220">rule <tt>ChangeMainFile</tt></a>), the name of these files
! 6734: might be defined by the following variable:</p>
! 6735: <pre> VarOutpuFile : FileName Value(SectionNumber)
! 6736: Extension;</pre>
! 6737: <p>
! 6738: If <tt>output.txt</tt> is the name of the <a name="varoutputfile">output
! 6739: file</a> specified when starting the translation program, translated sections
! 6740: are written in files <tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>
! 6741: </blockquote>
! 6742: </div>
! 6743:
! 6744: <div class="subsection">
! 6745:
! 6746: <h3><a name="sectc527">Translating structure elements</a></h3>
! 6747: <p>
! 6748: The <tt>RULES</tt> keyword introduces the translation rules which will be
1.1 cvs 6749: applied to the various structured element types. Translation rules can be
6750: specified for each element type defined in the structure schema, including the
1.18 ! cvs 6751: base types defined implicitly, whose names are <tt>TEXT_UNIT</tt>,
! 6752: <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>, <tt>GRAPHIC_UNIT</tt> and
! 6753: <tt>PAGE_UNIT</tt>. But it is not necessary to specify rules for every
! 6754: defined type.</p>
! 6755: <p>
1.1 cvs 6756: If there are no translation rules for an element type, the elements that it
6757: contains (and which may have rules themselves) will still be translated, but
6758: the translator will produce nothing for the element itself. To make the
1.18 ! cvs 6759: translator completely ignore the content of an element the <a
! 6760: href="#sectc5217"><tt>Remove</tt> rule</a> must be used.</p>
! 6761: <p>
1.1 cvs 6762: The translation rules for an element type defined in the structure schema are
6763: written using the name of the type followed by a colon and the list of
1.18 ! cvs 6764: applicable rules. When the element type is a <a href="#sectd3285">mark
! 6765: pair</a>, but only in this case, the type name must be preceded by the
! 6766: <tt>First</tt> or <tt>Second</tt> keyword. This keyword indicates whether the
! 6767: rules that follow apply to the first or second mark of the pair.</p>
! 6768: <p>
1.1 cvs 6769: The list of rules can take several forms. It may be a simple non-conditional
6770: rule. It can also be formed by a condition followed by one or more simple
1.18 ! cvs 6771: rules. Or it can be a block of rules beginning with the <tt>BEGIN</tt>
! 6772: keyword and ending with the <tt>END</tt> keyword and a semicolon. This block
1.1 cvs 6773: of rules can contain one or more simple rules and/or one or more conditions,
1.18 ! cvs 6774: each followed by one or more simple rules.</p>
! 6775: <pre> ElemSeq = TransType < TransType > .
1.1 cvs 6776: TransType = [ FirstSec ] ElemID ':' RuleSeq .
6777: FirstSec = 'First' / 'Second' .
6778: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
6779: Rule = SimpleRule / ConditionBlock .
6780: ConditionBlock = 'IF' ConditionSeq SimpleRuleSeq .
6781: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.18 ! cvs 6782: SimpleRule .</pre>
! 6783: </div>
1.1 cvs 6784:
1.18 ! cvs 6785: <div class="subsection">
1.1 cvs 6786:
1.18 ! cvs 6787: <h3><a name="sectc528">Conditional rules</a></h3>
! 6788: <p>
1.1 cvs 6789: In a translation schema, the translation rules are either associated with
6790: element types or with attribute values or with a specific presentation. They
6791: are applied by the translator each time an element of the corresponding type
6792: is encountered in the translated document or each time the attribute value is
6793: carried by an element or also, each time the specific translation is attached
6794: to an element. This systematic application of the rules can be relaxed: it is
6795: possible to add a condition to one or more rules, so that these rules are only
1.18 ! cvs 6796: applied when the condition is true.</p>
! 6797: <p>
! 6798: A condition begins with the keyword <tt>IF</tt>, followed by a sequence of
1.1 cvs 6799: elementary conditions. Elementary conditions are separated from each other by
1.18 ! cvs 6800: the <tt>AND</tt> keyword. If there is only one elementary condition, this
1.1 cvs 6801: keyword is absent. The rules are only applied if all the elementary
6802: conditions are true. The elementary condition can be negative; it is then
1.18 ! cvs 6803: preceded by the <tt>NOT</tt> keyword.</p>
! 6804: <p>
1.1 cvs 6805: When the translation rule(s) controlled by the condition apply to a reference
6806: element or a reference attribute, an elementary condition can also apply to
1.18 ! cvs 6807: element referred by this reference. The <tt>Target</tt> keyword is used for
1.1 cvs 6808: that purpose. It must appear before the keyword defining the condition
1.18 ! cvs 6809: type.</p>
! 6810: <p>
1.1 cvs 6811: Depending on their type, some conditions may apply either to the element with
1.5 cvs 6812: which they are associated, or to one of its ancestor. In the case of an
1.18 ! cvs 6813: ancestor, the key word <tt>Ancestor</tt> must be used, followed by</p>
! 6814: <ul>
! 6815: <li>
! 6816: either an integer which represents the number of levels in the tree between
! 6817: the element and the ancestor of interest,
! 6818: <li>
! 6819: or the type name of the ancestor of interest. If that type is defined in a
! 6820: separate structure schema, the name of that schema must follow between
1.1 cvs 6821: parentheses.
1.18 ! cvs 6822: </ul>
! 6823: <p>
1.2 cvs 6824: There is a special case for the parent element, which can be simply written
1.18 ! cvs 6825: <tt>Parent</tt> instead of <tt>Ancestor 1</tt>.</p>
! 6826: <p>
! 6827: Only conditions <tt>First</tt>, <tt>Last</tt>, <tt>Referred</tt>,
! 6828: <tt>Within</tt>, <tt>Attributes</tt>, <tt>Presentation</tt>, <tt>Comment</tt>
1.1 cvs 6829: and those concerning an attribute or a specific presentation can apply to an
1.18 ! cvs 6830: ancestor. Conditions <tt>Defined</tt>, <tt>FirstRef</tt>, <tt>LastRef</tt>,
! 6831: <tt>ExternalRef</tt>, <tt>Alphabet</tt>, <tt>FirstAttr</tt>,
! 6832: <tt>LastAttr</tt>, <tt>ComputedPage</tt>, <tt>StartPage</tt>,
! 6833: <tt>UserPage</tt>, <tt>ReminderPage</tt>, <tt>Empty</tt> cannot be preceded by
! 6834: keywords <tt>Parent</tt> or <tt>Ancestor</tt>.</p>
! 6835: <p>
! 6836: In condition <tt>Referred</tt> and in the condition that applies to a named
! 6837: attribute, a symbol '<tt>*</tt>' can indicate that the condition is related
1.5 cvs 6838: only to the element itself. If this symbol is not present, not only the
1.18 ! cvs 6839: element is considered, but also its ancestor, at any level.</p>
! 6840: <p>
1.1 cvs 6841: The form of an elementary condition varies according to the type of
1.18 ! cvs 6842: condition.</p>
1.1 cvs 6843:
1.18 ! cvs 6844: <div class="subsubsection">
1.1 cvs 6845:
1.18 ! cvs 6846: <h4><a name="sectd5281">Conditions based on the logical position of the
! 6847: element</a></h4>
! 6848: <p>
1.1 cvs 6849: The condition can be on the position of the element in the document's logical
6850: structure tree. It is possible to test whether the element is the first
1.18 ! cvs 6851: (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is not
! 6852: the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>).</p>
! 6853: <p>
1.1 cvs 6854: It is also possible to test if the element is contained in an element of a
1.18 ! cvs 6855: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). If that
1.1 cvs 6856: element type is defined in a structure schema which is not the one which
6857: corresponds to the translation schema, the type name of this element must be
6858: followed, between parentheses, by the name of the structure schema which
1.18 ! cvs 6859: defines it.</p>
! 6860: <p>
! 6861: If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
! 6862: condition is satisfied only if the <em>parent</em> element has the type
! 6863: indicated. If the word <tt>Immediately</tt> is missing, the condition is
! 6864: satisfied if any <em>ancestor</em> has the type indicated.</p>
! 6865: <p>
! 6866: An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.1 cvs 6867: type. It specifies the number of ancestors of the indicated type that must be
6868: present for the condition to be satisfied. If the keyword
1.18 ! cvs 6869: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
! 6870: element must have the indicated type. The integer <i>n</i> must be positive
! 6871: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
1.1 cvs 6872: maximum or minimum number of ancestors. If these symbols are missing, the
1.18 ! cvs 6873: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
! 6874: this number is missing, it is equivalent to > 0.</p>
! 6875: <p>
1.11 cvs 6876: If the condition applies to translation rules associated with an attribute,
1.18 ! cvs 6877: i.e. if it is in the <tt>ATTRIBUTES</tt> section of the presentation schema,
1.11 cvs 6878: the condition can be simply an element name. Translation rules are then
1.18 ! cvs 6879: executed only if the attribute is attached to an element of that type. The
! 6880: keyword <tt>NOT</tt> before the element name indicates that the translation
! 6881: rules must be executed only if the element is not of the type indicated.</p>
! 6882: </div>
1.1 cvs 6883:
1.18 ! cvs 6884: <div class="subsubsection">
1.1 cvs 6885:
1.18 ! cvs 6886: <h4><a name="sectd5282">Conditions on references</a></h4>
! 6887: <p>
1.1 cvs 6888: References may be taken into account in conditions, which can be based on the
1.18 ! cvs 6889: fact that the element, or one of its ancestors (unless symbol <tt>*</tt> is
! 6890: present), is designated by a at least one reference (<tt>Referred</tt>) or by
! 6891: none (<tt>NOT Referred</tt>). If the element or attribute to which the
1.1 cvs 6892: condition is attached is a reference, the condition can be based on the fact
6893: that it acts as the first reference to the designated element
1.18 ! cvs 6894: (<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>), or as a reference to
! 6895: an element located in another document (<tt>ExternalRef</tt>). Like all
! 6896: conditions, conditions on references can be inverted by the <tt>NOT</tt>
! 6897: keyword.</p>
! 6898: </div>
! 6899:
! 6900: <div class="subsubsection">
! 6901:
! 6902: <h4><a name="sectd5283">Conditions on the parameters</a></h4>
! 6903: <p>
! 6904: Elements which are <a href="#sectc326">parameters</a> can be given a
! 6905: particular condition which is based on whether or not the parameter is given a
! 6906: value in the document (<tt>Defined</tt> or <tt>NOT Defined</tt>,
! 6907: respectively).</p>
! 6908: </div>
1.1 cvs 6909:
1.18 ! cvs 6910: <div class="subsubsection">
1.1 cvs 6911:
1.18 ! cvs 6912: <h4><a name="sectd5284">Conditions on the alphabets</a></h4>
! 6913: <p>
1.1 cvs 6914: The character string base type (and only this type) can use the condition
1.18 ! cvs 6915: <tt>Alphabet = a</tt> which indicates that the translation rule(s) should only
1.1 cvs 6916: apply if the alphabet of the character string is the one whose name appears
1.18 ! cvs 6917: after the equals sign (or is not, if there is a preceding <tt>NOT</tt>
1.1 cvs 6918: keyword). This condition cannot be applied to translation rules of an
1.18 ! cvs 6919: attribute.</p>
! 6920: <p>
1.1 cvs 6921: In the current implementation of Thot, the available alphabets are the
1.18 ! cvs 6922: <tt>Latin</tt> alphabet and the <tt>Greek</tt> alphabet.</p>
! 6923: </div>
1.1 cvs 6924:
1.18 ! cvs 6925: <div class="subsubsection">
1.1 cvs 6926:
1.18 ! cvs 6927: <h4><a name="sectd5285">Conditions on page breaks</a></h4>
! 6928: <p>
1.1 cvs 6929: The page break base type (and only this type) can use the following
1.18 ! cvs 6930: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>, and
! 6931: <tt>ReminderPage</tt>. The <tt>ComputedPage</tt> condition indicates that the
1.1 cvs 6932: translation rule(s) should apply if the page break was created automatically
1.18 ! cvs 6933: by Thot; the <tt>StartPage</tt> condition is true if the page break is
! 6934: generated before the element by the <tt>Page</tt> rule of the P language; the
! 6935: <tt>UserPage</tt> condition applies if the page break was inserted by the
! 6936: user; and the <tt>ReminderPage</tt> is applied if the page break is a reminder
! 6937: of page breaking.</p>
! 6938: </div>
1.1 cvs 6939:
1.18 ! cvs 6940: <div class="subsubsection">
1.1 cvs 6941:
1.18 ! cvs 6942: <h4><a name="sectd5286">Conditions on the element's content</a></h4>
! 6943: <p>
1.1 cvs 6944: The condition can be based on whether or not the element is empty. An element
6945: which has no children or whose leaves are all empty is considered to be empty
1.18 ! cvs 6946: itself. This condition is expressed by the <tt>Empty</tt> keyword, optionally
! 6947: preceded by the <tt>NOT</tt> keyword.</p>
! 6948: </div>
1.1 cvs 6949:
1.18 ! cvs 6950: <div class="subsubsection">
1.1 cvs 6951:
1.18 ! cvs 6952: <h4><a name="sectd5287">Conditions on the presence of comments</a></h4>
! 6953: <p>
1.1 cvs 6954: The condition can be based on the presence or absence of comments associated
6955: with the translated element. This condition is expressed by the keyword
1.18 ! cvs 6956: <tt>Comment</tt>, optionally preceded by the keyword <tt>NOT</tt>.</p>
! 6957: </div>
1.1 cvs 6958:
1.18 ! cvs 6959: <div class="subsubsection">
1.1 cvs 6960:
1.18 ! cvs 6961: <h4><a name="sectd5288">Conditions on the presence of specific presentation
! 6962: rules</a></h4>
! 6963: <p>
1.1 cvs 6964: The condition can be based on the presence or absence of specific presentation
6965: rules associated with the translated element, whatever the rules, their value
6966: or their number. This condition is expressed by the keyword
1.18 ! cvs 6967: <tt>Presentation</tt>, optionally preceded by the <tt>NOT</tt> keyword.</p>
! 6968: </div>
1.1 cvs 6969:
1.18 ! cvs 6970: <div class="subsubsection">
1.1 cvs 6971:
1.18 ! cvs 6972: <h4><a name="sectd5289">Conditions on the presence of logical
! 6973: attributes</a></h4>
! 6974: <p>
1.1 cvs 6975: In the same way, the condition can be based on the presence or absence of
6976: attributes associated with the translated elements, no matter what the
1.18 ! cvs 6977: attributes or their values. The <tt>Attributes</tt> keyword expresses this
! 6978: condition.</p>
! 6979: </div>
1.1 cvs 6980:
1.18 ! cvs 6981: <div class="subsubsection">
1.1 cvs 6982:
1.18 ! cvs 6983: <h4><a name="sectd52810">Conditions on logical attributes</a></h4>
! 6984: <p>
1.1 cvs 6985: If the condition appears in the translation rules of an attribute, the
1.18 ! cvs 6986: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
1.1 cvs 6987: the rules must only be applied if this attribute is the first attribute for
6988: the translated element or if it is the last (respectively). These conditions
1.18 ! cvs 6989: can also be inverted by the <tt>NOT</tt> keyword.</p>
! 6990: <p>
1.1 cvs 6991: Another type of condition can only be applied to the translation rules when
1.18 ! cvs 6992: the element being processed (or one of its ancestors if symbol <tt>*</tt> is
1.1 cvs 6993: missing) has a certain attribute, perhaps with a certain value or, in
6994: contrast, when the element does not have this attribute with this value. The
6995: condition is specified by writing the name of the attribute after the keyword
1.18 ! cvs 6996: <tt>IF</tt> or <tt>AND</tt>. The <tt>NOT</tt> keyword can be used to invert
1.1 cvs 6997: the condition. If the translation rules must be applied to any element which
6998: has this attribute (or does not have it, if the condition is inverted) no
6999: matter what the attribute's value, the condition is complete. If, in
7000: contrast, the condition applies to one or more values of the attribute, these
7001: are indicated after the name of the attribute, except for reference attributes
1.18 ! cvs 7002: which do not have values.</p>
! 7003: <p>
! 7004: The representation of the values of an <a name="relattr">attribute</a> in a
1.1 cvs 7005: condition depends on the attribute's type. For attributes with enumerated or
7006: textual types, the value (a name or character string between apostrophes,
7007: respectively) is simply preceded by an equals sign. For numeric attributes,
7008: the condition can be based on a single value or on a range of values. In the
7009: case of a unique value, this value (an integer) is simply preceded by an
1.18 ! cvs 7010: equals sign. Conditions based on ranges of values have several forms:</p>
! 7011: <ul>
! 7012: <li>
! 7013: all values less than a given value (the value is preceded by a ``less than''
! 7014: sign).
! 7015: <li>
! 7016: all values greater than a given value (the value is preceded by a ``greater
1.1 cvs 7017: than'' sign).
1.18 ! cvs 7018: <li>
! 7019: all values falling in an interval, bounds included. The range of values is
! 7020: then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
1.2 cvs 7021: Minimum and Maximum are integers.
1.18 ! cvs 7022: </ul>
! 7023: <p>
1.2 cvs 7024: All numeric values may be negative. The integer is simply preceded by a minus
1.18 ! cvs 7025: sign.</p>
! 7026: <p>
! 7027: Both local and global attributes can be used in conditions.</p>
! 7028: </div>
1.1 cvs 7029:
1.18 ! cvs 7030: <div class="subsubsection">
1.1 cvs 7031:
1.18 ! cvs 7032: <h4><a name="sectd52811">Conditions on specific presentation rules</a></h4>
! 7033: <p>
1.1 cvs 7034: It is possible to apply translation rules only when the element being
7035: processed has or does not have a specific presentation rule, possibly with a
7036: certain value. The condition is specified by writing the name of the
1.18 ! cvs 7037: presentation rule after the keyword <tt>IF</tt> or <tt>AND</tt>. The
! 7038: <tt>NOT</tt> keyword can be used to invert the condition. If the translation
1.1 cvs 7039: rules must be applied to any element which has this presentation rule (or does
7040: not have it, if the condition is inverted) no matter what the rule's value,
7041: the condition is complete. If, in contrast, the condition applies to one or
7042: more values of the rule, these are indicated after the name of the
1.18 ! cvs 7043: attribute.</p>
! 7044: <p>
1.1 cvs 7045: The representation of presentation rule values in a condition is similar to
7046: that for attribute values. The representation of these values depend on the
7047: type of the presentation rule. There are three categories of presentation
1.18 ! cvs 7048: rules:</p>
! 7049: <ul>
! 7050: <li>
! 7051: those taking numeric values (<tt>Size, Indent, LineSpacing, LineWeight</tt>),
! 7052: <li>
! 7053: those with values taken from a predefined list (<tt>Adjust, Justify,
! 7054: Hyphenate, Style, Font, UnderLine, Thickness, LineStyle</tt>),
! 7055: <li>
! 7056: those whose value is a name (<tt>FillPattern, Background, Foreground</tt>).
! 7057: </ul>
! 7058: <p>
1.1 cvs 7059: For presentation rules which take numeric values, the condition can take a
7060: unique value or a range of values. In the case of a unique value, this value
7061: (an integer) is simply preceded by an equals sign. Conditions based on ranges
1.18 ! cvs 7062: of values have several forms:</p>
! 7063: <ul>
! 7064: <li>
! 7065: all values less than a given value (the value is preceded by a ``less than''
! 7066: sign).
! 7067: <li>
! 7068: all values greater than a given value (the value is preceded by a ``greater
1.1 cvs 7069: than'' sign).
1.18 ! cvs 7070: <li>
! 7071: all values falling in an interval, bounds included. The range of values is
! 7072: then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
1.2 cvs 7073: Minimum and Maximum are integers.
1.18 ! cvs 7074: </ul>
! 7075: <p>
! 7076: Values for the <tt>Indent</tt>rule may be negative. The integer is then
1.2 cvs 7077: simply preceded by a minus sign and represents how far the first line starts
1.18 ! cvs 7078: to the left of the other lines.</p>
! 7079: <p>
1.1 cvs 7080: For presentation rules whose values are taken from predefined lists, the value
7081: which satisfies the condition is indicated by an equals sign followed by the
1.18 ! cvs 7082: name of the value.</p>
! 7083: <p>
1.1 cvs 7084: For presentation rule whose values are names, the value which satisfies the
7085: condition is indicated by the equals sign followed by the value's name. The
1.18 ! cvs 7086: names of fill patterns (the <tt>FillPattern</tt> rule) and of colors (the
! 7087: <tt>Foreground</tt> and <tt>Background</tt> rules) known to Thot are the same
! 7088: as in the P language.</p>
! 7089: <p>
1.1 cvs 7090: The syntax of conditions based on the specific presentation is the same as the
1.18 ! cvs 7091: syntax used to express the <a href="#sectc5224">translation of specific
! 7092: presentation rules</a>.</p>
! 7093: <p>
1.1 cvs 7094: When a condition has only one rule, the condition is simply followed by that
7095: rule. If it has several rules, they are placed after the condition between
1.18 ! cvs 7096: the keywords <tt>BEGIN</tt> and <tt>END</tt>.</p>
! 7097: <pre> ConditionSeq = Condition [ 'AND' Condition ] .
1.1 cvs 7098: Condition = [ 'NOT' ] [ 'Target' ] Cond .
7099: Cond = CondElem / CondAscend .
7100: CondElem ='FirstRef' / 'LastRef' /
7101: 'ExternalRef' /
7102: 'Defined' /
7103: 'Alphabet' '=' Alphabet /
7104: 'ComputedPage' / 'StartPage' /
7105: 'UserPage' / 'ReminderPage' /
7106: 'Empty' /
1.11 cvs 7107: ElemID /
1.1 cvs 7108: 'FirstAttr' / 'LastAttr' .
7109: CondAscend = [ Ascend ] CondOnAscend .
7110: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
7111: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
7112: CondRelLevel = NUMBER .
7113: CondOnAscend ='First' / 'Last' /
7114: 'Referred' /
7115: [ 'Immediately' ] 'Within' [ NumParent ]
7116: ElemID [ ExtStruct ] /
7117: 'Attributes' /
7118: AttrID [ RelatAttr ] /
7119: 'Presentation' /
7120: PresRule /
7121: 'Comment' .
7122: NumParent = [ GreaterLess ] NParent .
7123: GreaterLess = '>' / '<' .
7124: NParent = NUMBER.
7125: ExtStruct = '(' ElemID ')' .
7126: Alphabet = NAME .
7127: RelatAttr ='=' Value /
7128: '>' [ '-' ] Minimum /
7129: '<' [ '-' ] Maximum /
7130: 'IN' '[' [ '-' ] MinInterval '..'
7131: [ '-' ] MaxInterval ']' .
7132: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
7133: Minimum = NUMBER .
7134: Maximum = NUMBER .
7135: MinInterval = NUMBER .
7136: MaxInterval = NUMBER .
7137: IntegerVal = NUMBER .
7138: TextVal = STRING .
1.18 ! cvs 7139: AttrValue = NAME .</pre>
! 7140: <blockquote class="example">
! 7141: <p>
! 7142: <strong>Example:</strong></p>
! 7143: <p>
1.3 cvs 7144: Suppose that after each element of type Section_Title it is useful to produce
1.18 ! cvs 7145: the text <tt>\label{SectX}</tt> where <tt>X</tt> represents the section
! 7146: number, but only if the section is designated by one or more references in the
! 7147: document. The following conditional rule produces this effect:</p>
! 7148: <pre>RULES
1.1 cvs 7149: Section_Title :
7150: IF Referred
1.18 ! cvs 7151: Create ('\label{Sect' Value(UniqueSectNum) '}\12') After;</pre>
! 7152: <p>
! 7153: (the declaration of the <a href="#sectc5224"><tt>UniqueSectNum</tt>
! 7154: counter</a> is given above). The string <tt>\12</tt> represents a line
! 7155: break.</p>
! 7156: </blockquote>
! 7157: <blockquote class="example">
! 7158: <p>
! 7159: <strong>Example:</strong></p>
! 7160: <p>
1.3 cvs 7161: Suppose that for elements of the Elmnt type it would be useful to produce a
7162: character indicating the value of the numeric attribute Level associated with
7163: the element: an ``A'' for all values of Level less than 3, a ``B'' for values
7164: between 3 and 10 and a ``C'' for values greater than 10. This can be achieved
1.18 ! cvs 7165: by writing the following rules for the Elmnt type:</p>
! 7166: <pre>RULES
1.1 cvs 7167: Elmnt :
7168: BEGIN
7169: IF Level < 3
7170: Create 'A';
7171: IF Level IN [3..10]
7172: Create 'B';
7173: IF Level > 10
7174: Create 'C';
1.18 ! cvs 7175: END;</pre>
! 7176: </blockquote>
! 7177: </div>
! 7178: </div>
1.1 cvs 7179:
1.18 ! cvs 7180: <div class="subsection">
1.1 cvs 7181:
1.18 ! cvs 7182: <h3><a name="sectc529">Translation rules</a></h3>
! 7183: <p>
1.14 cvs 7184: Fifteen types of translation rules can be associated with element types and
1.18 ! cvs 7185: attribute values. They are the <tt>Create</tt>, <tt>Write</tt>,
! 7186: <tt>Read</tt>, <tt>Include</tt>, <tt>Get</tt>, <tt>Copy</tt>, <tt>Use</tt>,
! 7187: <tt>Remove</tt>, <tt>NoTranslation</tt>, <tt>NoLineBreak</tt>,
! 7188: <tt>ChangeMainFile</tt>, <tt>RemoveFile</tt>, <tt>Set</tt>, <tt>Add</tt>,
! 7189: <tt>Indent</tt>, rules. Each rule has its own syntax, although they are all
! 7190: based on very similar models.</p>
! 7191: <pre> SimpleRule = 'Create' [ 'IN' VarID ] Object
1.1 cvs 7192: [ Position ] ';' /
7193: 'Write' Object [ Position ] ';' /
7194: 'Read' BufferID [ Position ] ';' /
7195: 'Include' File [ Position ] ';' /
7196: 'Get' [ RelPosition ] ElemID
7197: [ ExtStruct ]
7198: [ Position ] ';' /
7199: 'Copy' [ RelPosition ] ElemID
7200: [ ExtStruct ]
7201: [ Position ] ';' /
7202: 'Use' TrSchema [ 'For' ElemID ] ';' /
7203: 'Remove' ';' /
7204: 'NoTranslation' ';' /
7205: 'NoLineBreak' ';' /
7206: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 7207: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 7208: 'Set' CounterID InitValue [ Position ] ';' /
7209: 'Add' CounterID Increment [ Position ] ';' /
7210: 'Indent' [ 'IN' VarID ] [ IndentSign ]
1.18 ! cvs 7211: IndentValue [ Position ] ';' .</pre>
! 7212: </div>
! 7213:
! 7214: <div class="subsection">
! 7215:
! 7216: <h3><a name="sectc5210">The <tt>Create</tt> rule</a></h3>
! 7217: <p>
! 7218: The most frequently used rule is undoubtedly the <tt>Create</tt> rule, which
! 7219: generates fixed or variable text (called an <em>object</em>) in the output
1.1 cvs 7220: file. The generated text can be made to appear either before or after the
7221: content of the element to which the rule applies. The rule begins with the
1.18 ! cvs 7222: <tt>Create</tt> keyword, followed by a specifier for the object and a keyword
! 7223: (<tt>Before</tt> or <tt>After</tt>) indicating the position of the generated
! 7224: text (<a href="#sectc5222">before or after</a> the element's content). If the
1.1 cvs 7225: position is not indicated, the object will be generated before the element's
7226: content. This rule, like all translation rules, is terminated by a
1.18 ! cvs 7227: semicolon.</p>
! 7228: <p>
! 7229: The <tt>Create</tt> keyword can be followed by the <tt>IN</tt> keyword and by
1.1 cvs 7230: the name of a variable. This means that the text generated by the rule must
7231: not be written in the main output file, but in the file whose name is
1.18 ! cvs 7232: specified by the variable.</p>
! 7233: <p>
1.1 cvs 7234: This allows the translation program to generate text in different files during
1.14 cvs 7235: the same run. These files do not need to be explicitely declared or opened.
1.18 ! cvs 7236: They do not need to be closed either, but if they contain temporary data, they
! 7237: can be removed (see the <a href="#sectc5220a"><tt>RemoveFile</tt> rule</a>).
! 7238: As soon as the translation program executes a <tt>Create</tt> rule for a file
! 7239: that is not yet open, it opens the file. These files are closed when the
! 7240: translation is finished.</p>
! 7241: <pre> 'Create' [ 'IN' VarID ] Object
1.1 cvs 7242: [ Position ] ';'
7243: Object = ConstID / CharString /
7244: BufferID /
7245: VarID /
7246: '(' Function < Function > ')' /
7247: AttrID /
7248: 'Value' /
7249: 'Content' /
7250: 'Comment' /
7251: 'Attributes' /
7252: 'Presentation' /
7253: 'RefId' /
7254: 'PairId' /
7255: 'FileDir' /
7256: 'FileName' /
7257: 'Extension' /
7258: 'DocumentName' /
7259: 'DocumentDir' /
7260: [ 'Referred' ] ReferredObject .
7261: Position ='After' / 'Before' .
7262:
7263: ReferredObject = VarID /
7264: ElemID [ ExtStruct ] /
7265: 'RefId' /
7266: 'DocumentName' /
1.18 ! cvs 7267: 'DocumentDir' .</pre>
! 7268: <p>
! 7269: The object to be generated can be:</p>
! 7270: <ul>
! 7271: <li>
! 7272: a constant string, specified by its name if it is declared in the schema's
! 7273: <tt>CONST</tt> section, or given directly as a value between apostrophes;
! 7274: <li>
! 7275: the contents of a buffer, designated by the name of the buffer;
! 7276: <li>
! 7277: a variable, designated by its name if it is declared in the translation
! 7278: schema's <tt>VAR</tt> section, or given directly between parentheses. The
! 7279: text generated is the value of that variable evaluated for the element to
! 7280: which the rule applies.
! 7281: <li>
! 7282: the value of an attribute, if the element being translated has this attribute.
! 7283: The attribute is specified by its name;
! 7284: <li>
! 7285: the value of a specific presentation rule. This object can only be generated
! 7286: if the translation rule is for a <a href="#prestransl">specific presentation
! 7287: rule</a>. It is specified by the <tt>Value</tt> keyword;
! 7288: <li>
! 7289: the element's content. That is, the content of the leaves of the subtree of
! 7290: the translated element. This is specified by the <tt>Content</tt> keyword;
! 7291: <li>
! 7292: the comment attached to the element. When the element doesn't have a comment,
! 7293: nothing is generated. This is indicated by the <tt>Comment</tt> keyword;
! 7294: <li>
! 7295: the translation of all attributes of the element (which is primarily used to
! 7296: apply the attribute translation rules <a href="#sectc5222">before</a> those of
! 7297: the element type). This is specified by the <tt>Attributes</tt> keyword.
! 7298: <li>
! 7299: the translation of all of the element's specific presentation rules (which is
! 7300: primarily used to apply the translation rules for the specific presentation
! 7301: rules <a href="#sectc5222">before</a> those of the element or its attributes).
! 7302: This option is specified by the <tt>Presentation</tt> keyword;
! 7303: <li>
! 7304: The value of the reference's identifier.<br>
! 7305: Thot associates a unique identifier with each element in a document. This
! 7306: identifier (called <em>reference's identifier</em> or <em>label</em>) is a
! 7307: character string containing the letter `L' followed by digits. Thot uses it
! 7308: in references for identifying the referred element.<br>
! 7309: The <tt>RefId</tt> keyword produces the reference's identifier of the element
! 7310: to which the translation rule is applied, or the reference's identifier of its
! 7311: first ancestor that is referred by a reference or that can be referred by a
! 7312: reference.
! 7313: <li>
! 7314: the value of a mark pair's unique identifier. This may only be used for <a
! 7315: href="#sectd3285">mark pairs</a> and is indicated by the <tt>PairId</tt>
1.2 cvs 7316: keyword.
1.18 ! cvs 7317: <li>
! 7318: the directory containing the file being generated (this string includes an
! 7319: ending '/', if it is not empty). This is indicated by the <tt>FileDir</tt>
1.2 cvs 7320: keyword.
1.18 ! cvs 7321: <li>
! 7322: the name of the file being generated (only the name, without the directory and
! 7323: without the extension). This is indicated by the <tt>FileName</tt> keyword.
! 7324: <li>
! 7325: the extension of the file being generated (this string starts with a dot, if
! 7326: it is not empty). This is indicated by the <tt>Extension</tt> keyword.
! 7327: <li>
! 7328: the name of the document being translated. This is indicated by the
! 7329: <tt>DocumentName</tt> keyword.
! 7330: <li>
! 7331: the directory containing the document being translated. This is indicated by
! 7332: the <tt>DocumentDir</tt> keyword.
! 7333: </ul>
! 7334: <p>
1.1 cvs 7335: When the rule applies to a reference (an element or an attribute defined as a
7336: reference in the structure schema), it can generate a text related to the
7337: element referred by that reference. The rule name is then followed the
1.18 ! cvs 7338: <tt>Referred</tt> keyword and a specification of the object to be generated
! 7339: for the referred element. This specification can be:</p>
! 7340: <ul>
! 7341: <li>
! 7342: the name of a variable. The rule generates the value of that variable,
1.1 cvs 7343: computed for the referred element.
1.18 ! cvs 7344: <li>
! 7345: an element type. The rule generates the translation of the element of that
! 7346: type, which is in the subtree of the referred element. If this element is not
! 7347: defined in the structure schema which corresponds to the translation schema
! 7348: (that is, an object defined in another schema), the element's type name must
! 7349: be followed by the name of its structure schema between parentheses.
! 7350: <li>
! 7351: the <tt>RefId</tt> keyword. The rule generates the reference's identifier of
! 7352: the referred element.
! 7353: <li>
! 7354: the <tt>DocumentName</tt> keyword. The rule generates the name of the
1.1 cvs 7355: document to which the referred element belongs.
1.18 ! cvs 7356: <li>
! 7357: the <tt>DocumentDir</tt> keyword. The rule generates the name of the
1.1 cvs 7358: directory that contains the document of the referred element.
1.18 ! cvs 7359: </ul>
! 7360: </div>
1.1 cvs 7361:
1.18 ! cvs 7362: <div class="subsection">
1.1 cvs 7363:
1.18 ! cvs 7364: <h3><a name="sectc5211">The <tt>Write</tt> rule</a></h3>
! 7365: <p>
! 7366: The <tt>Write</tt> has the same syntax as the <tt>Create</tt> rule. It also
1.1 cvs 7367: produces the same effect, but the generated text is displayed on the user's
7368: terminal during the translation of the document, instead of being produced in
7369: the translated document. This is useful for helping the user keep track of
7370: the progress of the translation and for prompting the user on the terminal for
1.18 ! cvs 7371: input required by the <tt>Read</tt> rule.</p>
! 7372: <pre> 'Write' Object [ Position ] ';'</pre>
! 7373: <p>
1.1 cvs 7374: Notice: if the translator is launched by the editor (by the ``Save as''
1.18 ! cvs 7375: command), messages produced by the <tt>Write</tt> rule are not displayed.</p>
! 7376: <blockquote class="example">
! 7377: <p>
! 7378: <strong>Example:</strong></p>
! 7379: <p>
1.3 cvs 7380: To make the translator display the number of each section being translated on
1.18 ! cvs 7381: the user's terminal, the following rule is specified for the <tt>Section</tt>
! 7382: element type:</p>
! 7383: <pre>Section : BEGIN
1.1 cvs 7384: Write VarSection;
7385: ...
1.18 ! cvs 7386: END;</pre>
! 7387: <p>
! 7388: (see <a href="#varsectexample">above</a> for the definition of the
! 7389: <tt>VarSection</tt> variable).</p>
! 7390: <p>
1.1 cvs 7391: To display text on the terminal before issuing a read operation with the
1.18 ! cvs 7392: <tt>Read</tt> rule, the following rule is used:</p>
! 7393: <pre>BEGIN
1.1 cvs 7394: Write 'Enter the name of the destination: ';
7395: ...
1.18 ! cvs 7396: END;</pre>
! 7397: </blockquote>
! 7398: </div>
! 7399:
! 7400: <div class="subsection">
! 7401:
! 7402: <h3><a name="sectc5212">The <tt>Read</tt> rule</a></h3>
! 7403: <p>
! 7404: The <tt>Read</tt> rule reads text from the terminal during the translation of
1.1 cvs 7405: the document and saves the text read in one of the buffers declared in the
1.18 ! cvs 7406: <tt>BUFFERS</tt> section of the schema. The buffer to be used is indicated by
! 7407: its name, after the <tt>READ</tt> keyword. This name can be followed, as in
! 7408: the <tt>Create</tt> and <tt>Write</tt> rules, by a keyword indicating if the
! 7409: read operation must be performed <tt>Before</tt> or <tt>After</tt> the
1.1 cvs 7410: translation of the element's content. If this keyword is absent, the read
7411: operation is done beforehand. The text is read into the buffer and remains
1.5 cvs 7412: there until a rule using the same buffer - possibly the same rule - is
1.18 ! cvs 7413: applied.</p>
! 7414: <pre> 'Read' BufferID [ Position ] ';'</pre>
! 7415: <blockquote class="example">
! 7416: <p>
! 7417: <strong>Example:</strong></p>
! 7418: <p>
1.3 cvs 7419: The following set of rules tells the user that the translator is waiting for
7420: the entry of some text, reads this text into a buffer and copies the text into
1.18 ! cvs 7421: the translated document.</p>
! 7422: <pre>BEGIN
1.1 cvs 7423: Write 'Enter the name of the destination: ';
7424: Read DestName;
7425: Create DestName;
7426: ...
1.18 ! cvs 7427: END;</pre>
! 7428: <p>
! 7429: (see <a href="#destname">above</a> the definition of <tt>DestName</tt>).</p>
! 7430: </blockquote>
! 7431: </div>
! 7432:
! 7433: <div class="subsection">
! 7434:
! 7435: <h3><a name="sectc5213">The <tt>Include</tt> rule</a></h3>
! 7436: <p>
! 7437: The <tt>Include</tt> rule, like the <tt>Create</tt> rule, is used to produce
1.1 cvs 7438: text in the translated document. It inserts constant text which is not
7439: defined in the translation schema, but is instead taken from a file. The
1.18 ! cvs 7440: file's name is specified after the <tt>Include</tt> keyword, either directly
1.1 cvs 7441: as a character string between apostrophes or as the name of one of the buffers
1.18 ! cvs 7442: declared in the <tt>BUFFERS</tt> section of the schema. In the latter case,
1.1 cvs 7443: the buffer is assumed to contain the file's name. This can be used when the
7444: included file's name is known only at the moment of translation. This only
1.18 ! cvs 7445: requires that the <tt>Include</tt> rule is preceded by a <tt>Read</tt> rule
! 7446: which puts the name of the file desired by the user into the buffer.</p>
! 7447: <p>
1.1 cvs 7448: Like the other rules, it is possible to specify whether the inclusion will
7449: occur before or after the element's content, with the default being before.
7450: The file inclusion is only done at the moment of translation, not during the
7451: compilation of the translation schema. Thus, the file to be included need not
7452: exist during the compilation, but it must be accessible at the time of
7453: translation. Its contents can also be modified between two translations, thus
7454: producing different results, even if neither the document or the translation
1.18 ! cvs 7455: schema are modified.</p>
! 7456: <p>
1.1 cvs 7457: During translation, the file to be included is searched for along the schema
1.18 ! cvs 7458: directory path (indicated by the environment variable <tt>THOTSCH</tt>). The
1.1 cvs 7459: file name is normally only composed of a simple name, without specification of
1.12 cvs 7460: a complete file path. However, if the filename starts with a '/', it is
1.18 ! cvs 7461: considered as an absolute path.</p>
! 7462: <pre> 'Include' File [ Position ] ';'
1.6 cvs 7463: File = FileName / BufferID .
1.18 ! cvs 7464: FileName = STRING .</pre>
! 7465: <blockquote class="example">
! 7466: <p>
! 7467: <strong>Example:</strong></p>
! 7468: <p>
1.3 cvs 7469: Suppose that it is desirable to print documents of the Article class with a
7470: formatter which requires a number of declarations and definitions at the
1.18 ! cvs 7471: beginning of the file. The <tt>Include</tt>rule can be used to achieve this.
1.3 cvs 7472: All the declarations and definitions a replaced in a file called
1.18 ! cvs 7473: <tt>DeclarArt</tt> and then the <tt>Article</tt> element type is given the
! 7474: following rule:</p>
! 7475: <pre>Article : BEGIN
1.1 cvs 7476: Include 'DeclarArt' Before;
7477: ...
1.18 ! cvs 7478: END;</pre>
! 7479: </blockquote>
! 7480: </div>
! 7481:
! 7482: <div class="subsection">
! 7483:
! 7484: <h3><a name="sectc5214">The <tt>Get</tt> rule</a></h3>
! 7485: <p>
! 7486: The <tt>Get</tt> rule is used to change the order in which the elements appear
1.1 cvs 7487: in the translated document. More precisely, it produces the translation of a
7488: specified element before or after the translation of the content of the
1.18 ! cvs 7489: element to which the rule applies. The <tt>Before</tt> and <tt>After</tt>
1.1 cvs 7490: keywords are placed at the end of the rule to specify whether the operation
7491: should be performed before or after translation of the rule's element (the
7492: default is before). The type of the element to be moved must be specified
1.18 ! cvs 7493: after the <tt>Get</tt> keyword, optionally preceded by a keyword indicating
! 7494: where the element will be found in the logical structure of the document:</p>
! 7495: <dl>
! 7496: <dt><tt>Included</tt></dt>
! 7497: <dd>
! 7498: The element to be moved is the first element of the indicated type which is
1.1 cvs 7499: found inside the element to which the rule applies.
1.18 ! cvs 7500: </dd>
! 7501: <dt><tt>Referred</tt></dt>
! 7502: <dd>
! 7503: This keyword can only be used if the rule applies to a reference element. The
! 7504: element to be moved is either the element designated by the reference (if that
! 7505: element is of the specified type), or the first element of the desired type
! 7506: contained within the element designated by the reference.
! 7507: </dd>
! 7508: <dt>no keyword</dt>
! 7509: <dd>
! 7510: If the element to be moved is an associated element, defined in the <a
! 7511: href="#sectc314"><tt>ASSOC</tt> section</a> of the structure schema, all
1.2 cvs 7512: associated elements of this type which have not been translated yet are then
7513: translated. Certain elements may in fact have already been translated by a
1.18 ! cvs 7514: <tt>Get Referred</tt> rule.
! 7515: <p>
1.1 cvs 7516: If the element to be moved is not an associated element, the translator takes
7517: the first element of the indicated type from among the siblings of the rule's
7518: element. This is primarily used to change the order of the components of an
1.18 ! cvs 7519: aggregate.</p>
! 7520: </dd>
! 7521: </dl>
! 7522: <p>
1.1 cvs 7523: If the element to be moved is defined in a structure schema which is not the
7524: one which corresponds to the translation schema (in the case of an included
7525: object with a different schema), the type name of this element must be
7526: followed, between parentheses, by the name of the structure schema which
1.18 ! cvs 7527: defines it.</p>
! 7528: <pre> 'Get' [ RelPosition ] ElemID
1.6 cvs 7529: [ ExtStruct ]
7530: [ Position ] ';' /
7531: RelPosition = 'Included' / 'Referred' .
1.18 ! cvs 7532: ExtStruct = '(' ElemID ')' .</pre>
! 7533: <p>
! 7534: The <tt>Get</tt> rule has no effect if the element which it is supposed to
1.1 cvs 7535: move has already been translated. Thus, the element will not be duplicated.
7536: It is generally best to associate the rule with the first element which will
7537: be encountered by the translator in its traversal of the document. Suppose an
1.18 ! cvs 7538: aggregate has two elements <tt>A</tt> and <tt>B</tt>, with <tt>A</tt>
1.1 cvs 7539: appearing first in the logical structure. To permute these two elements, a
1.18 ! cvs 7540: <tt>Get B before</tt> rule should be associated with the <tt>A</tt> element
! 7541: type, not the inverse. Similarly, a rule of the form <tt>Get Included X
! 7542: After</tt>, even though syntactically correct, makes no sense since, by the
1.1 cvs 7543: time it will be applied, after the translation of the contents of the element
1.18 ! cvs 7544: to which it is attached, the <tt>X</tt> element will already have been
! 7545: translated.</p>
! 7546: <p>
! 7547: The <tt>Get</tt> rule is the only way to obtain the translation of the
1.1 cvs 7548: associated elements. In fact, the translator only traverses the primary tree
7549: of the document and thus does not translate the associated elements, except
1.18 ! cvs 7550: when the translation is explicitly required by a <tt>Get Referred Type</tt> or
! 7551: <tt>Get Type</tt> rule where <tt>Type</tt> is an associated element type.</p>
! 7552: <blockquote class="example">
! 7553: <p>
! 7554: <strong>Example:</strong></p>
! 7555: <p>
1.3 cvs 7556: The structure schema defined figures as associated element which are composed
7557: of some content and a caption. Moreover, it is possible to make references to
1.18 ! cvs 7558: figures, using elements of the <tt>RefFigure</tt> type:</p>
! 7559: <pre> ...
1.1 cvs 7560: RefFigure = REFERENCE(Figure);
7561: ASSOC
1.6 cvs 7562: Figure = BEGIN
7563: Content = NATURE;
7564: Caption = Text;
7565: END;
1.18 ! cvs 7566: ...</pre>
! 7567: <p>
1.3 cvs 7568: Suppose it would be useful to make a figure appear in the translated document
7569: at the place in the text where the first reference to the figure is made. If
7570: some figures are not referenced, then they would appear at the end of the
7571: document. Also, each figure's caption should appear before the content. The
1.18 ! cvs 7572: following rules in the translation schema will produce this result:</p>
! 7573: <pre>Article : BEGIN
1.1 cvs 7574: ...
7575: Get Figures After;
7576: END;
7577: RefFigure : BEGIN
7578: If FirstRef Get Referred Figure;
7579: ...
7580: END;
7581: Content : BEGIN
7582: Get Caption Before;
7583: ...
1.18 ! cvs 7584: END;</pre>
! 7585: </blockquote>
! 7586: </div>
! 7587:
! 7588: <div class="subsection">
! 7589:
! 7590: <h3><a name="sectc5215">The <tt>Copy</tt> rule</a></h3>
! 7591: <p>
! 7592: Like the <tt>Get</tt> rule, the <tt>Copy</tt> rule generates the translation
1.1 cvs 7593: of a specified element, but it acts even if the element has already been
7594: translated and it allows to copy it or to translate it later. Both rules have
1.18 ! cvs 7595: the same syntax.</p>
! 7596: <pre> 'Copy' [ RelPosition ] ElemID
! 7597: [ ExtStruct ] [ Position ] ';'</pre>
! 7598: </div>
! 7599:
! 7600: <div class="subsection">
! 7601:
! 7602: <h3><a name="sectc5216">The <tt>Use</tt> rule</a></h3>
! 7603: <p>
! 7604: The <tt>Use</tt> rule specifies the translation schema to be applied to
1.1 cvs 7605: objects of a certain class that are part of the document. This rule only
7606: appears in the rules for the root element of the document (the first type
1.18 ! cvs 7607: defined after the <tt>STRUCT</tt> keyword in the structure schema) or the
1.1 cvs 7608: rules of an element defined by an external structure (by another structure
1.18 ! cvs 7609: schema). Also, the <tt>Use</tt> rule cannot be conditional.</p>
! 7610: <p>
1.1 cvs 7611: If the rule is applied to an element defined by an external structure, the
1.18 ! cvs 7612: <tt>Use</tt> keyword is simply followed by the name of the translation schema
1.1 cvs 7613: to be used for element constructed according to that external structure. If
7614: the rule is applied to the document's root element, it is formed by the
1.18 ! cvs 7615: <tt>Use</tt> keyword followed by the translation schema's name, the
! 7616: <tt>For</tt> keyword and the name of the external structure to which the
! 7617: indicated translation schema should be applied.</p>
! 7618: <pre> 'Use' TrSchema [ 'For' ElemID ] ';'
! 7619: TrSchema = NAME .</pre>
! 7620: <p>
! 7621: If no <tt>Use</tt> rule defines the translation schema to be used for an
1.1 cvs 7622: external structure which appears in a document, the translator asks the user,
7623: during the translation process, which schema should be used. Thus, it is not
1.18 ! cvs 7624: necessary to give the translation schema a <tt>Use</tt> rule for every
1.1 cvs 7625: external structure used, especially when the choice of translation schemas is
1.18 ! cvs 7626: to be left to the user.</p>
! 7627: <p>
1.1 cvs 7628: Notice: if the translator is launched by the editor (by the ``Save as''
1.18 ! cvs 7629: command), prompts are not displayed.</p>
! 7630: <blockquote class="example">
! 7631: <p>
! 7632: <strong>Example:</strong></p>
! 7633: <p>
! 7634: The <tt>Article</tt> structure schema uses the <tt>Formula</tt> external
! 7635: structure, defined by another structure schema, for mathematical formulas:</p>
! 7636: <pre>STRUCTURE Article;
1.1 cvs 7637: ...
7638: STRUCT
7639: Article = ...
7640: ...
7641: Formula_in_text = Formula;
7642: Isolated_formula = Formula;
7643: ...
1.18 ! cvs 7644: END</pre>
! 7645: <p>
! 7646: Suppose that it would be useful to use the <tt>FormulaT</tt> translation
! 7647: schema for the formulas of an article. This can be expressed in two different
! 7648: ways in the <tt>Article</tt> class translation schema, using the rules:</p>
! 7649: <pre>RULES
1.1 cvs 7650: Article :
1.18 ! cvs 7651: Use FormulaT for Formula;</pre>
! 7652: <p>
! 7653: or:</p>
! 7654: <pre>RULES
1.1 cvs 7655: ...
7656: Formula :
1.18 ! cvs 7657: Use FormulaT;</pre>
! 7658: </blockquote>
! 7659: </div>
! 7660:
! 7661: <div class="subsection">
! 7662:
! 7663: <h3><a name="sectc5217">The <tt>Remove</tt> rule</a></h3>
! 7664: <p>
! 7665: The <tt>Remove</tt> rule indicates that nothing should be generated, in the
1.1 cvs 7666: translated document, for the content of the element to which the rule applies.
7667: The content of that element is simply ignored by the translator. This does
7668: not prevent the generation of text for the element itself, using the
1.18 ! cvs 7669: <tt>Create</tt> or <tt>Include</tt> rules, for example.</p>
! 7670: <p>
! 7671: The <tt>Remove</tt> rule is simply written with the <tt>Remove</tt> keyword.
! 7672: It is terminated, like all rules, by a semicolon.</p>
! 7673: <pre> 'Remove' ';'</pre>
! 7674: </div>
! 7675:
! 7676: <div class="subsection">
! 7677:
! 7678: <h3><a name="sectc5218">The <tt>NoTranslation</tt> rule</a></h3>
! 7679: <p>
! 7680: The <tt>NoTranslation</tt> rule indicates to the translator that it must not
1.1 cvs 7681: translate the content of the leaves of the element to which it applies. In
1.18 ! cvs 7682: contrast to the <tt>Remove</tt> rule, it does not suppress the content of the
1.1 cvs 7683: element, but it inhibits the translation of character strings, symbols, and
7684: graphical elements contained in the element. These are retrieved so that
1.18 ! cvs 7685: after the translation of the document, the rules of the <a
! 7686: href="#sectc5225"><tt>TEXTTRANSLATE</tt>, <tt>SYMBTRANSLATE</tt> and
! 7687: <tt>GRAPHTRANSLATE</tt> sections</a> will not be applied to them.</p>
! 7688: <p>
! 7689: The <tt>NoTranslation</tt> rule is written with the <tt>NoTranslation</tt>
! 7690: keyword followed by a semicolon.</p>
! 7691: <pre> 'NoTranslation' ';'</pre>
! 7692: </div>
! 7693:
! 7694: <div class="subsection">
! 7695:
! 7696: <h3><a name="sectc5219">The <tt>NoLineBreak</tt> rule</a></h3>
! 7697: <p>
! 7698: The <tt>NoLineBreak</tt> rule indicates to the translator that it must not
1.1 cvs 7699: generate additional line breaks in the output produced for the element to
1.18 ! cvs 7700: which it applies. This is as if it was an <a href="#sectc522">instruction
! 7701: <tt>LINELENGTH 0;</tt></a> at the beginning of the translation schema, but
! 7702: only for the current element.</p>
! 7703: <p>
! 7704: The <tt>NoLineBreak</tt> rule is written with the <tt>NoLineBreak</tt> keyword
! 7705: followed by a semicolon.</p>
! 7706: <pre> 'NoLineBreak' ';'</pre>
! 7707: </div>
1.1 cvs 7708:
1.18 ! cvs 7709: <div class="subsection">
1.1 cvs 7710:
1.18 ! cvs 7711: <h3><a name="sectc5220">The <tt>ChangeMainFile</tt> rule</a></h3>
! 7712: <p>
1.1 cvs 7713: When the translation program starts, it opens a main output file, whose name
1.18 ! cvs 7714: is given as a parameter of the translator. All <a
! 7715: href="#sectc5210"><tt>Create</tt> rules</a> without explicit indication of the
! 7716: output file write sequentially in this file. When a <tt>ChangeMainFile</tt>
! 7717: rule is executed, the main output file is closed and it is replaced by a new
! 7718: one, whose name is specified in the <tt>ChangeMainFile</tt> rule. The
! 7719: <tt>Create</tt> rules without indication of the output file that are then
! 7720: executed write in this new file. Several <tt>ChangeMainFile</tt> rules can be
! 7721: executed during the same translation, for dividing the main output into
! 7722: several files.</p>
! 7723: <p>
! 7724: This rule is written with the <tt>ChangeMainFile</tt> keyword followed by the
1.14 cvs 7725: name of a variable that specifies the name of the new main file. The keyword
1.18 ! cvs 7726: <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule to
1.1 cvs 7727: specify whether the operation should be performed before or after translation
7728: of the rule's element (the default is before). This rule, like all translation
1.18 ! cvs 7729: rules, is terminated by a semicolon.</p>
! 7730: <pre> 'ChangeMainFile' VarID [ Position ] ';'</pre>
! 7731: <blockquote class="example">
! 7732: <p>
! 7733: <strong>Example:</strong></p>
! 7734: <p>
1.3 cvs 7735: To generate the translation of each section in a different file, the following
1.18 ! cvs 7736: rule can be associated with type <tt>Section</tt>. That rule uses the <a
! 7737: href="#varoutputfile"><tt>VarOutpuFile</tt> variable</a> defined above.</p>
! 7738: <pre> Section:
! 7739: ChangeMainFile VarOutpuFile Before;</pre>
! 7740: <p>
! 7741: If <tt>output.txt</tt> is the name of the output file specified when starting
1.3 cvs 7742: the translation program, translated sections are written in files
1.18 ! cvs 7743: <tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>
! 7744: </blockquote>
! 7745: </div>
1.1 cvs 7746:
1.18 ! cvs 7747: <div class="subsection">
1.14 cvs 7748:
1.18 ! cvs 7749: <h3><a name="sectc5220a">The <tt>RemoveFile</tt> rule</a></h3>
! 7750: <p>
1.14 cvs 7751: Files may be used for storing temporary data that are no longer needed when
1.18 ! cvs 7752: the translation of a document is complete. These files may be removed by the
! 7753: <tt>RemoveFile</tt> rule.</p>
! 7754: <p>
! 7755: This rule is written with the <tt>RemoveFile</tt> keyword followed by the name
! 7756: of a variable that specifies the name of the file to be removed. The keyword
! 7757: <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule to
! 7758: specify whether the operation should be performed before or after translation
! 7759: of the rule's element (the default is before). This rule, like all
! 7760: translation rules, is terminated by a semicolon.</p>
! 7761: <pre> 'RemoveFile' VarID [ Position ] ';'</pre>
! 7762: </div>
! 7763:
! 7764: <div class="subsection">
! 7765:
! 7766: <h3><a name="sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a></h3>
! 7767: <p>
! 7768: The <tt>Set</tt> and <tt>Add</tt> rules are used for modifying the value of
! 7769: counters that have no <a href="#sectc524">counting function</a>. Only this
! 7770: type of counter can be used in the <tt>Set</tt> and <tt>Add</tt> rules.</p>
! 7771: <p>
! 7772: Both rules have the same syntax: after the keyword <tt>Set</tt> or
! 7773: <tt>Add</tt> appear the counter name and the value to assign to the counter
! 7774: (<tt>Set</tt> rule) or the value to be added to the counter (<tt>Add</tt>
! 7775: rule). The keyword <tt>Before</tt> or <tt>After</tt> can follow that value to
1.1 cvs 7776: indicate when the rule must be applied: before or after the element's content
1.18 ! cvs 7777: is translated. By default, <tt>Before</tt> is assumed. A semicolon terminates
! 7778: the rule.</p>
! 7779: <pre> 'Set' CounterID InitValue [ Position ] ';' /
! 7780: 'Add' CounterID Increment [ Position ] ';'</pre>
! 7781: </div>
! 7782:
! 7783: <div class="subsection">
! 7784:
! 7785: <h3><a name="sectc5221a">The <tt>Indent</tt> rule</a></h3>
! 7786: <p>
! 7787: The <tt>Indent</tt> rule is used to modify the value of text indentation in
! 7788: the output files.</p>
! 7789: <p>
! 7790: Each time the translator creates a new line in an output file, it generates a
! 7791: variable number of space characters at the beginning of the new line. By
1.10 cvs 7792: default, the number of these characters (the indentation) is 0. It can be
1.18 ! cvs 7793: changed with the <tt>Indent</tt> rule.</p>
! 7794: <p>
! 7795: The rule begins with the <tt>Indent</tt> keyword, followed by the indentation
! 7796: sign (optional) and value and a keyword <tt>Before</tt> or <tt>After</tt>
! 7797: indicating that the indentation should be changed <a href="#sectc5222">before
! 7798: or after</a> the element's content is generated. If the position is not
1.10 cvs 7799: indicated, the indentation is changed before the element's content is
7800: generated. This rule, like all translation rules, is terminated by a
1.18 ! cvs 7801: semicolon.</p>
! 7802: <p>
! 7803: The indentation value is indicated by an integer, which is the number of space
! 7804: characters to be generated at the beginning of each new line. A sign
! 7805: (<tt>+</tt> or <tt>-</tt>) can appear before the integer to indicate that the
! 7806: value is relative: the current value of indentation is incremented (if sign is
! 7807: <tt>+</tt>) or decremented (if sign is <tt>-</tt>) by the specified value.</p>
! 7808: <p>
! 7809: Like the <a href="#sectc5210"><tt>Create</tt> rule</a>, the <tt>Indent</tt>
! 7810: keyword can be followed by the <tt>IN</tt> keyword and by the name of a <a
! 7811: href="#sectc526">variable</a>. This means that the rule must not change
1.10 cvs 7812: indentation in the main output file, but in the file whose name is specified
7813: by the variable (by default, indentation is changed in the main output
1.18 ! cvs 7814: file).</p>
! 7815: <pre> 'Indent' [ 'IN' VarID ] [ IndentSign ]
1.10 cvs 7816: IndentValue [ Position ] ';' .
7817:
7818: IndentSign = '+' / '-' .
1.18 ! cvs 7819: IndentValue = NUMBER .</pre>
! 7820: </div>
1.10 cvs 7821:
1.18 ! cvs 7822: <div class="subsection">
1.1 cvs 7823:
1.18 ! cvs 7824: <h3><a name="sectc5222">Rule application order</a></h3>
! 7825: <p>
1.1 cvs 7826: The translator translates the elements which comprise the document in the
1.18 ! cvs 7827: order induced by the tree structure, except when the <tt>Get</tt> rule is used
1.1 cvs 7828: to change the order of translation. For each element, the translator first
7829: applies the rules specified for the element's type that must be applied before
1.18 ! cvs 7830: translation of the element's content (rules ending with the <tt>Before</tt>
1.1 cvs 7831: keyword or which have no position keyword). If several rules meet these
7832: criteria, the translator applies them in the order in where they appear in the
1.18 ! cvs 7833: translation schema.</p>
! 7834: <p>
! 7835: It then applies all <a href="#sectc5223">rules for the attributes</a> which
1.1 cvs 7836: the element has and which must be applied before the translation of the
1.18 ! cvs 7837: element's content (rules ending with the <tt>Before</tt> keyword or which have
1.1 cvs 7838: no position keyword). For one attribute value, the translator applies the
1.18 ! cvs 7839: rules in the order in which they are defined in the translation schema.</p>
! 7840: <p>
1.1 cvs 7841: The same procedure is followed with translation rules for specific
1.18 ! cvs 7842: presentations.</p>
! 7843: <p>
! 7844: Next, the element's content is translated, as long as a <tt>Remove</tt> rule
! 7845: does not apply.</p>
! 7846: <p>
1.1 cvs 7847: In the next step, the translator applies rules for the specific presentation
7848: of the element that are to be applied after translation of the content (rules
1.18 ! cvs 7849: which end with the <tt>After</tt> keyword). The rules for each type of
1.1 cvs 7850: presentation rule or each value are applied in the order in which the
1.18 ! cvs 7851: translation appear in the schema.</p>
! 7852: <p>
1.1 cvs 7853: Then, the same procedure is followed for translation rules for attributes of
1.18 ! cvs 7854: the element.</p>
! 7855: <p>
1.1 cvs 7856: Finally, the translator applies rules for the element which must be applied
7857: after translation of the element's content. These rules are applied in the
7858: order that they appear in the translation schema. When the translation of an
7859: element is done, the translator procedes to translate the following
1.18 ! cvs 7860: element.</p>
! 7861: <p>
! 7862: This order can be changed with the <tt>Attributes</tt> and
! 7863: <tt>Presentation</tt> options of the <a href="#sectc5210"><tt>Create</tt>
! 7864: rule</a>.</p>
! 7865: </div>
1.1 cvs 7866:
1.18 ! cvs 7867: <div class="subsection">
1.1 cvs 7868:
1.18 ! cvs 7869: <h3><a name="sectc5223">Translation of logical attributes</a></h3>
! 7870: <p>
1.1 cvs 7871: After the rules for the element types, the translation schema defines rules
1.18 ! cvs 7872: for attribute values. This section begins with the <tt>ATTRIBUTES</tt>
1.1 cvs 7873: keyword and is composed of a sequence of rule blocks each preceded by an
1.18 ! cvs 7874: attribute name and an optional value or value range.</p>
! 7875: <p>
1.1 cvs 7876: If the attribute's name appears alone before the rule block, the rule are
7877: applied to all element which have the attribute, no matter what value the
7878: attribute has. In this case, the attribute name is followed by a colon before
1.18 ! cvs 7879: the beginning of the rule block.</p>
! 7880: <p>
1.1 cvs 7881: The attribute's name can be followed by the name of an element type between
7882: parentheses. This says, as in presentation schemas, that the rule block which
7883: follows applies not to the element which has the attribute, but to its
1.18 ! cvs 7884: descendants of the type indicated between the parentheses.</p>
! 7885: <p>
1.1 cvs 7886: If values are given after the attribute name (or after the name of the element
7887: type), the rules are applied only when the attribute has the indicated values.
7888: The same attribute can appear several times, with different values and
7889: different translation rules. Attribute values are indicated in the same way
1.18 ! cvs 7890: as in <a href="#sectc528">conditions</a> and are followed by a colon before
! 7891: the block of rules.</p>
! 7892: <p>
1.1 cvs 7893: The rule block associated with an attribute is either a simple rule or a
1.18 ! cvs 7894: sequence of rules delimited by the <tt>BEGIN</tt> and <tt>END</tt> keywords.
! 7895: Note that rules associated with attribute values cannot be conditional.</p>
! 7896: <p>
1.1 cvs 7897: Translation rules are not required for all attributes (or their values)
7898: defined in a structure schema. Only those attributes for which a particular
7899: action must be performed by the translator must have such rules. The rules
1.18 ! cvs 7900: that can be used are those described above, from <a
! 7901: href="#sectc5210"><tt>Create</tt></a> to <a
! 7902: href="#sectc5218"><tt>NoTranslation</tt></a>.</p>
! 7903: <pre> AttrSeq = TransAttr < TransAttr > .
1.1 cvs 7904: TransAttr = AttrID [ '(' ElemID ')' ]
7905: [ RelatAttr ] ':' RuleSeq .
7906: AttrID = NAME .
1.18 ! cvs 7907: ElemID = NAME .</pre>
! 7908: <blockquote class="example">
! 7909: <p>
! 7910: <strong>Example:</strong></p>
! 7911: <p>
1.3 cvs 7912: The structure defined the ``Language'' attribute which can take the values
7913: ``French'' and ``English''. To have the French parts of the original document
7914: removed and prevent the translation of the leaves of the English parts, the
1.18 ! cvs 7915: following rules would be used:</p>
! 7916: <pre>ATTRIBUTES
1.1 cvs 7917: Language=French :
7918: Remove;
7919: Language=English :
1.18 ! cvs 7920: NoTranslation;</pre>
! 7921: </blockquote>
! 7922: </div>
1.1 cvs 7923:
1.18 ! cvs 7924: <div class="subsection">
1.1 cvs 7925:
1.18 ! cvs 7926: <h3><a name="sectc5224">Translation of specific presentations</a></h3>
! 7927: <p>
1.1 cvs 7928: After the rules for attributes, the translation schema defines rules for the
1.18 ! cvs 7929: specific presentation. This section begins with the <tt>PRESENTATION</tt>
1.1 cvs 7930: keyword and is composed of a sequence of translation rule blocks each preceded
7931: by a presentation rule name, optionally accompanied by a part which depends on
1.18 ! cvs 7932: the particular presentation rule.</p>
! 7933: <p>
1.1 cvs 7934: Each of these translation rule blocks is applied when the translator operates
7935: on an element which has a specific presentation rule of the type indicated at
7936: the head of the block. Depending on the type of the specific presentation
7937: rule, it is possible to specify values of the presentation rule for which the
1.18 ! cvs 7938: translation rule block should be applied.</p>
! 7939: <p>
! 7940: There are three categories of the presentation rules:</p>
! 7941: <ul>
! 7942: <li>
! 7943: rules taking numeric values: <tt>Size</tt>, <tt>Indent</tt>,
! 7944: <tt>LineSpacing</tt>, <tt>LineWeight</tt>,
! 7945: <li>
! 7946: rules whose values are taken from a predefined list (i.e. whose type is an
! 7947: enumeration): <tt>Adjust</tt>, <tt>Justify</tt>, <tt>Hyphenate,/TT>,
! 7948: <tt>Style</tt>, <tt>Font</tt>, <tt>UnderLine</tt>, <tt>Thickness</tt>,
! 7949: <tt>LineStyle</tt>,</tt>
! 7950: <li>
! 7951: rules whose value is a name: <tt>FillPattern</tt>, <tt>Background</tt>,
! 7952: <tt>Foreground</tt>.
! 7953: </ul>
! 7954: <p>
1.1 cvs 7955: For presentation rules of the first category, the values which provoke
7956: application of the translation rules are indicated in the same manner as for
1.18 ! cvs 7957: <a href="#relattr">numeric attributes</a>. This can be either a unique value
1.1 cvs 7958: or range of values. For a unique value, the value (an integer) is simply
7959: preceded by an equals sign. Value ranges can be specified in one of three
1.18 ! cvs 7960: ways:</p>
! 7961: <ul>
! 7962: <li>
! 7963: all values less than a given value (this value is preceded by a ``less than''
! 7964: sign '<tt><</tt>'),
! 7965: <li>
! 7966: all values greater than a given value (this value is preceded by a` `greater
! 7967: than'' sign '<tt>></tt>'),
! 7968: <li>
! 7969: all values falling in an interval, bounds included. The range of values is
! 7970: then specified <tt>IN [</tt>Minimum<tt>..</tt>Maximum<tt>]</tt>, where Minimum
! 7971: and Maximum are integers.
! 7972: </ul>
! 7973: <p>
1.2 cvs 7974: All numeric values can be negative, in which case the integer is preceded by a
1.18 ! cvs 7975: minus sign. All values must be given in typographers points.</p>
! 7976: <p>
1.1 cvs 7977: For presentation rules whose values are taken from a predefined list, the
7978: value which provokes application of the translation rules is simply indicated
1.18 ! cvs 7979: by the equals sign followed by the name of the value.</p>
! 7980: <p>
1.1 cvs 7981: For presentation rules whose values are names, the value which provokes the
7982: application of translation rules is simply indicated by the equals sign
7983: followed by the name of the value. The names of the fill patterns (the
1.18 ! cvs 7984: <tt>FillPattern</tt> rule) and of the colors (the <tt>Foreground</tt> and
! 7985: <tt>Background</tt> rules) used in Thot are the same as in the P language.</p>
! 7986: <pre> PresSeq = PresTrans < PresTrans > .
1.1 cvs 7987: PresTrans = PresRule ':' RuleSeq .
7988: PresRule = 'Size' [ PresRelation ] /
7989: 'Indent' [ PresRelation ] /
7990: 'LineSpacing' [ PresRelation ] /
7991: 'Adjust' [ '=' AdjustVal ] /
7992: 'Justify' [ '=' BoolVal ] /
7993: 'Hyphenate' [ '=' BoolVal ] /
7994: 'Style' [ '=' StyleVal ] /
7995: 'Font' [ '=' FontVal ] /
7996: 'UnderLine' [ '=' UnderLineVal ] /
7997: 'Thickness' [ '=' ThicknessVal ] /
7998: 'LineStyle' [ '=' LineStyleVal ] /
7999: 'LineWeight' [ PresRelation ] /
8000: 'FillPattern' [ '=' Pattern ] /
8001: 'Background' [ '=' Color ] /
8002: 'Foreground' [ '=' Color ] .
8003:
8004: PresRelation = '=' PresValue /
8005: '>' [ '-' ] PresMinimum /
8006: '<' [ '-' ] PresMaximum /
8007: 'IN' '[' [ '-' ] PresIntervalMin '..'
8008: [ '-' ] PresIntervalMax ']' .
8009: AdjustVal = 'Left' / 'Right' / 'VMiddle' /
8010: 'LeftWithDots' .
8011: BoolVal = 'Yes' / 'No' .
8012: StyleVal = 'Bold' / 'Italics' / 'Roman' /
8013: 'BoldItalics' / 'Oblique' /
8014: 'BoldOblique' .
8015: FontVal = 'Times' / 'Helvetica' / 'Courier' .
8016: UnderLineVal = 'NoUnderline' / 'UnderLined' /
8017: 'OverLined' / 'CrossedOut' .
8018: ThicknessVal = 'Thick' / 'Thin' .
1.6 cvs 8019: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
1.1 cvs 8020: Pattern = NAME .
8021: Color = NAME .
8022: PresMinimum = NUMBER .
8023: PresMaximum = NUMBER .
8024: PresIntervalMin= NUMBER .
8025: PresIntervalMax= NUMBER .
8026: PresValue = [ '-' ] PresVal .
1.18 ! cvs 8027: PresVal = NUMBER .</pre>
! 8028: <p>
! 8029: The <a name="prestransl">translation rules associated with specific
! 8030: presentation rules</a> can use the value of the specific presentation rule
1.1 cvs 8031: that causes them to be applied. This behavior is designated by the keyword
1.18 ! cvs 8032: <tt>Value</tt>. For numerically-valued presentation rules, the numeric value
1.1 cvs 8033: is produced. For other presentation rules, the name of the value is
1.18 ! cvs 8034: produced.</p>
! 8035: <p>
1.1 cvs 8036: It should be noted that modifications to the layout of the document's elements
8037: that are made using the combination of the control key and a mouse button will
1.18 ! cvs 8038: have no effect on the translation of the document.</p>
! 8039: <blockquote class="example">
! 8040: <p>
! 8041: <strong>Example:</strong></p>
! 8042: <p>
1.3 cvs 8043: Suppose that it is desirable to use the same font sizes as in the specific
1.18 ! cvs 8044: presentation, but the font size must be between 10 and 18 typographer's
! 8045: points. If font size is set in the translated document by the string
! 8046: <tt>pointsize=n</tt> where <tt>n</tt> is the font size in typographer's points
! 8047: then the following rules will suffice:</p>
! 8048: <pre>PRESENTATION
1.1 cvs 8049: Size < 10 :
8050: Create 'pointsize=10';
8051: Size in [10..18] :
8052: BEGIN
8053: Create 'pointsize=';
8054: Create Value;
8055: END;
8056: Size > 18 :
1.18 ! cvs 8057: Create 'pointsize=18';</pre>
! 8058: </blockquote>
! 8059: </div>
1.1 cvs 8060:
1.18 ! cvs 8061: <div class="subsection">
1.1 cvs 8062:
1.18 ! cvs 8063: <h3><a name="sectc5225">Recoding of characters, symbols and graphics</a></h3>
! 8064: <p>
1.1 cvs 8065: The coding of characters, graphical elements and symbols as defined in Thot
8066: does not necessarily correspond to what is required by an application to which
8067: a Thot document must be exported. Because of this the translator can recode
8068: these terminal elements of the documents structure. The last sections of a
8069: translation schema are intended for this purpose, each specifying the recoding
1.18 ! cvs 8070: rules for one type of terminal element.</p>
! 8071: <p>
1.1 cvs 8072: The recoding rules for character strings are grouped by alphabets. There is a
8073: group of rules for each alphabet of the Thot document that must be translated.
1.18 ! cvs 8074: Each such group of rules begins with the <tt>TEXTTRANSLATE</tt> keyword,
1.1 cvs 8075: followed by the specification of the alphabet to translate and the recoding
1.18 ! cvs 8076: rules, between the <tt>BEGIN</tt> and <tt>END</tt> keywords unless there is
1.1 cvs 8077: only one recoding rule for the alphabet. The specification of the alphabet is
8078: not required: by default it is assumed to the Latin alphabet (the ISO Latin-1
1.18 ! cvs 8079: character set).</p>
! 8080: <p>
1.1 cvs 8081: Each recoding rule is formed by a source string between apostrophes and a
8082: target string, also between apostrophes, the two strings being separated by
1.18 ! cvs 8083: the arrow symbol (<tt>-></tt>), formed by the ``minus'' and ``greater than''
! 8084: characters. The rule is terminated by a semi-colon.</p>
! 8085: <pre> TextTransSeq = [ Alphabet ] TransSeq .
1.1 cvs 8086: Alphabet = NAME .
8087: TransSeq ='BEGIN' < Translation > 'END' ';' /
8088: Translation .
8089: Translation = Source [ '->' Target ] ';' .
8090: Source = STRING .
1.18 ! cvs 8091: Target = STRING .</pre>
! 8092: <p>
1.1 cvs 8093: One such rule signifies that when the source string appears in a text leaf of
8094: the document being translated, the translator must replace it, in the
8095: translated document, with the target string. The source string and the target
8096: string can have different lengths and the target string can be empty. In this
8097: last case, the translator simply suppresses every occurrence of the source
1.18 ! cvs 8098: string in the translated document.</p>
! 8099: <p>
1.1 cvs 8100: For a given alphabet, the order of the rules is not important and has no
8101: significance because the T language compiler reorders the rules in ways that
8102: speed up the translator's work. The total number of recoding rules is limited
1.18 ! cvs 8103: by the compiler as is the maximum length of the source and target strings.</p>
! 8104: <p>
1.1 cvs 8105: The recoding rules for symbols and graphical elements are written in the same
8106: manner as the recoding rules for character strings. They are preceded,
1.18 ! cvs 8107: respectively, by the <tt>SYMBTRANSLATE</tt> and <tt>GRAPHTRANSLATE</tt> and so
1.1 cvs 8108: not require a specification of the alphabet. Their source string is limited to
8109: one character, since, in Thot, each symbol and each graphical element is
8110: represented by a single character. The symbol and graphical element codes are
1.18 ! cvs 8111: defined along with the <a href="#sect7">non-standard character codes</a>.</p>
! 8112: <blockquote class="example">
! 8113: <p>
! 8114: <strong>Example:</strong></p>
! 8115: <p>
! 8116: In a translation schema producing documents destined for use with the
! 8117: L<sup>A</sup>T<sub><big>E</big></sub>X formatter, the Latin
1.1 cvs 8118: characters``é'' (octal code 351 in Thot) and ``è'' (octal code
1.18 ! cvs 8119: 350 in Thot) must be converted to their representation in
! 8120: L<sup>A</sup>T<sub><big>E</big></sub>X:</p>
! 8121: <pre>TEXTTRANSLATE Latin
1.1 cvs 8122: BEGIN
8123: '\350' -> '\`{e}'; { e grave }
8124: '\351' -> '\''{e}'; { e acute }
1.18 ! cvs 8125: END;</pre>
! 8126: </blockquote>
! 8127: </div>
! 8128: </div>
! 8129: <hr>
! 8130: </div>
1.1 cvs 8131:
1.18 ! cvs 8132: <div class="chapter">
1.1 cvs 8133:
1.18 ! cvs 8134: <h1><a name="sect6">Language grammars</a></h1>
! 8135: <p>
1.1 cvs 8136: This chapter gives the complete grammars of the languages of Thot. The
8137: grammars were presented and described in the preceding chapters, which also
8138: specify the semantics of the languages. This section gives only the
1.18 ! cvs 8139: syntax.</p>
1.1 cvs 8140:
1.18 ! cvs 8141: <div class="section">
1.1 cvs 8142:
1.18 ! cvs 8143: <h2><a name="sectb61">The M meta-language</a></h2>
! 8144: <p>
1.1 cvs 8145: The language grammars are all expressed in the same formalism, the M
1.18 ! cvs 8146: meta-language, which is defined in this section.</p>
! 8147: <pre>{ Any text between braces is a comment. }
1.1 cvs 8148: Grammar = Rule < Rule > 'END' .
8149: { The < and > signs indicate zero }
8150: { or more repetitions. }
8151: { END marks the end of the grammar. }
8152: Rule = Ident '=' RightPart '.' .
8153: { The period indicates the end of a rule }
8154: RightPart = RtTerminal / RtIntermed .
8155: { The slash indicates a choice }
8156: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
8157: { Right part of a terminal rule }
8158: RtIntermed = Possibility < '/' Possibility > .
8159: { Right part of an intermediate rule }
8160: Possibility = ElemOpt < ElemOpt > .
8161: ElemOpt = Element / '[' Element < Element > ']' /
8162: '<' Element < Element > '>' .
8163: { Brackets delimit optional parts }
8164: Element = Ident / KeyWord .
8165: Ident = NAME .
8166: { Identifier, sequence of characters
8167: KeyWord = STRING .
8168: { Character string delimited by apostrophes }
1.18 ! cvs 8169: END</pre>
! 8170: </div>
1.1 cvs 8171:
1.18 ! cvs 8172: <div class="section">
1.1 cvs 8173:
1.18 ! cvs 8174: <h2><a name="sectb62">The S language</a></h2>
! 8175: <p>
1.1 cvs 8176: The S language is used to write structure schemas, which contain the generic
8177: logical structures of document and object classes. It is described here in
1.18 ! cvs 8178: the M meta-language.</p>
! 8179: <pre>StructSchema = 'STRUCTURE' [ 'EXTENSION' ] ElemID ';'
1.1 cvs 8180: 'DEFPRES' PresID ';'
8181: [ 'ATTR' AttrSeq ]
8182: [ 'PARAM' RulesSeq ]
8183: [ 'STRUCT' RulesSeq ]
8184: [ 'EXTENS' ExtensRuleSeq ]
8185: [ 'ASSOC' RulesSeq ]
8186: [ 'UNITS' RulesSeq ]
8187: [ 'EXPORT' SkeletonSeq ]
8188: [ 'EXCEPT' ExceptSeq ]
8189: 'END' .
8190:
8191: ElemID = NAME .
8192: PresID = NAME .
8193:
8194: AttrSeq = Attribute < Attribute > .
8195: Attribute = AttrID '=' AttrType ';' .
8196: AttrType = 'INTEGER' / 'TEXT' /
8197: 'REFERENCE' '(' RefType ')' /
8198: ValueSeq .
8199: RefType = 'ANY' /
8200: [ FirstSec ] ElemID [ ExtStruct ] .
8201: ValueSeq = AttrVal < ',' AttrVal > .
8202: AttrID = NAME .
8203: FirstSec = 'First' / 'Second' .
8204: ExtStruct = '(' ElemID ')' .
8205: AttrVal = NAME .
8206:
8207: RulesSeq = Rule < Rule > .
8208: Rule = ElemID [ LocAttrSeq ] '='
8209: DefWithAttr ';' .
8210: LocAttrSeq = '(' 'ATTR' LocalAttr
8211: < ';' LocalAttr > ')' .
8212: LocalAttr = [ '!' ] AttrID [ '=' AttrType ] .
8213: DefWithAttr = Definition
8214: [ '+' '(' ExtensionSeq ')' ]
8215: [ '-' '(' RestrictSeq ')' ]
8216: [ 'WITH' FixedAttrSeq ] .
8217: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
8218: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
8219: 'SYMBOL' / 'PICTURE' .
8220: RestrictSeq = RestrictElem < ',' RestrictElem > .
8221: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
8222: 'SYMBOL' / 'PICTURE' .
8223: FixedAttrSeq = FixedAttr < ',' FixedAttr > .
8224: FixedAttr = AttrID [ FixedOrModifVal ] .
8225: FixedOrModifVal= [ '?' ] '=' FixedValue .
8226: FixedValue = [ '-' ] NumValue / TextValue / AttrVal .
8227: NumValue = NUMBER .
8228: TextValue = STRING .
8229:
8230: Definition = BaseType [ LocAttrSeq ] / Constr /
8231: Element .
8232: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' /
8233: 'PICTURE' / 'UNIT' / 'NATURE' .
8234: Element = ElemID [ ExtOrDef ] .
8235: ExtOrDef = 'EXTERN' / 'INCLUDED' /
8236: [ LocAttrSeq ] '=' Definition .
8237:
8238: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
8239: '(' DefWithAttr ')' /
8240: 'BEGIN' DefOptSeq 'END' /
8241: 'AGGREGATE' DefOptSeq 'END' /
8242: 'CASE' 'OF' DefSeq 'END' /
8243: 'REFERENCE' '(' RefType ')' /
8244: 'PAIR' .
8245:
8246: min = Integer / '*' .
8247: max = Integer / '*' .
8248: Integer = NUMBER .
8249:
8250: DefOptSeq = DefOpt ';' < DefOpt ';' > .
8251: DefOpt = [ '?' ] DefWithAttr .
8252:
8253: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .
8254:
8255: SkeletonSeq = SkeletonElem < ',' SkeletonElem > ';' .
8256: SkeletonElem = ElemID [ 'WITH' Contents ] .
8257: Contents = 'Nothing' / ElemID [ ExtStruct ] .
8258:
8259: ExceptSeq = Except ';' < Except ';' > .
8260: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr ':'
8261: ExcValSeq .
8262: ExcTypeOrAttr = ElemID / AttrID .
8263: ExcValSeq = ExcValue < ',' ExcValue > .
8264: ExcValue = 'NoCut' / 'NoCreate' /
8265: 'NoHMove' / 'NoVMove' / 'NoMove' /
8266: 'NoHResize' / 'NoVResize' / 'NoResize' /
1.18 ! cvs 8267: 'MoveResize' /
1.1 cvs 8268: 'NewWidth' / 'NewHeight' /
8269: 'NewHPos' / 'NewVPos' /
8270: 'Invisible' / 'NoSelect' /
8271: 'Hidden' / 'ActiveRef' /
8272: 'ImportLine' / 'ImportParagraph' /
1.9 cvs 8273: 'NoPaginate' / 'ParagraphBreak' /
8274: 'HighlightChildren' / 'ExtendedSelection' /
8275: 'ReturnCreateNL' .
1.1 cvs 8276:
8277: ExtensRuleSeq = ExtensRule ';' < ExtensRule ';' > .
8278: ExtensRule = RootOrElem [ LocAttrSeq ]
8279: [ '+' '(' ExtensionSeq ')' ]
8280: [ '-' '(' RestrictSeq ')' ]
8281: [ 'WITH' FixedAttrSeq ] .
8282: RootOrElem = 'Root' / ElemID .
8283:
1.18 ! cvs 8284: END</pre>
! 8285: </div>
1.1 cvs 8286:
1.18 ! cvs 8287: <div class="section">
1.1 cvs 8288:
1.18 ! cvs 8289: <h2><a name="sectb63">The P language</a></h2>
! 8290: <p>
1.1 cvs 8291: The P language is used to write presentation schemas, which define the
8292: graphical presentation rules to be applied to different classes of documents
1.18 ! cvs 8293: and objects. It is described here in the M meta-language.</p>
! 8294: <pre>PresSchema = 'PRESENTATION' ElemID ';'
1.1 cvs 8295: [ 'VIEWS' ViewSeq ]
8296: [ 'PRINT' PrintViewSeq ]
8297: [ 'COUNTERS' CounterSeq ]
8298: [ 'CONST' ConstSeq ]
8299: [ 'VAR' VarSeq ]
8300: [ 'DEFAULT' ViewRuleSeq ]
8301: [ 'BOXES' BoxSeq ]
8302: [ 'RULES' PresentSeq ]
8303: [ 'ATTRIBUTES' PresAttrSeq ]
8304: [ 'TRANSMIT' TransmitSeq ]
8305: 'END' .
8306:
8307: ElemID = NAME .
8308:
8309: ViewSeq = ViewDeclaration
8310: < ',' ViewDeclaration > ';' .
8311: ViewDeclaration = ViewID [ 'EXPORT' ] .
8312: ViewID = NAME .
8313:
8314: PrintViewSeq = PrintView < ',' PrintView > ';' .
8315: PrintView = ViewID / ElemID .
8316:
8317: CounterSeq = Counter < Counter > .
8318: Counter = CounterID ':' CounterFunc ';' .
8319: CounterID = NAME .
8320: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
8321: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
8322: SetFunction < SetFunction >
8323: AddFunction < AddFunction >
8324: [ 'INIT' AttrID ] /
1.16 cvs 8325: 'RLEVEL' 'OF' ElemID .
1.1 cvs 8326: SLevelAsc = [ '-' ] LevelAsc .
8327: LevelAsc = NUMBER .
8328: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
8329: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
8330: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 8331: [ '*' ] ElemID .
1.1 cvs 8332: CounterValue = NUMBER .
8333:
8334: ConstSeq = Const < Const > .
8335: Const = ConstID '=' ConstType ConstValue ';' .
8336: ConstID = NAME .
8337: ConstType = 'Text' [ Alphabet ] / 'Symbol' /
8338: 'Graphics' / 'Picture' .
8339: ConstValue = STRING .
8340: Alphabet = NAME .
8341:
8342: VarSeq = Variable < Variable > .
8343: Variable = VarID ':' FunctionSeq ';' .
8344: VarID = NAME .
8345: FunctionSeq = Function < Function > .
8346: Function = 'DATE' / 'FDATE' /
8347: 'DocName' / 'DirName' /
8348: 'ElemName' / 'AttributeName' /
8349: ConstID / ConstType ConstValue /
8350: AttrID /
8351: 'VALUE' '(' PageAttrCtr ','
8352: CounterStyle ')' .
8353: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
8354: [ MinMax ] CounterID / AttrID .
8355: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
8356: 'Uppercase' / 'Lowercase' .
8357: MinMax = 'MaxRangeVal' / 'MinRangeVal' .
8358:
8359: BoxSeq = Box < Box > .
8360: Box = 'FORWARD' BoxID ';' /
8361: BoxID ':' ViewRuleSeq .
8362: BoxID = NAME .
8363:
8364: PresentSeq = Present < Present > .
8365: Present = [ '*' ] [ FirstSec ] ElemID ':'
8366: ViewRuleSeq .
8367: FirstSec = 'First' / 'Second' .
8368:
8369: PresAttrSeq = PresAttr < PresAttr > .
8370: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
8371: [ AttrRelation ] ':' ViewRuleSeq .
8372: AttrID = NAME .
8373: AttrRelation = '=' AttrVal /
8374: '>' [ '-' ] MinValue /
8375: '<' [ '-' ] MaxValue /
8376: 'IN' '[' [ '-' ] LowerBound '..'
8377: [ '-' ] UpperBound ']' /
8378: 'GREATER' AttrID /
8379: 'EQUAL' AttrID /
8380: 'LESS' AttrID .
8381: AttrVal = [ '-' ] EqualNum / EqualText / AttrValue .
8382: MinValue = NUMBER .
8383: MaxValue = NUMBER .
8384: LowerBound = NUMBER .
8385: UpperBound = NUMBER.
8386: EqualNum = NUMBER .
8387: EqualText = STRING .
8388: AttrValue = NAME .
8389:
8390: ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
8391: 'END' ';' /
8392: ViewRules / CondRules / Rule .
8393: RulesAndCond = CondRules / Rule .
8394: ViewRules = 'IN' ViewID CondRuleSeq .
8395: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
8396: CondRules / Rule .
8397: CondRules = CondRule < CondRule >
8398: [ 'Otherwise' RuleSeq ] .
8399: CondRule = 'IF' ConditionSeq RuleSeq .
8400: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' / Rule .
8401:
1.6 cvs 8402: ConditionSeq = Condition < 'AND' Condition > .
8403: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
8404: ConditionElem = 'First' / 'Last' /
8405: [ 'Immediately' ] 'Within' [ NumParent ]
8406: ElemID [ ExtStruct ] /
8407: ElemID /
8408: 'Referred' / 'FirstRef' / 'LastRef' /
8409: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
8410: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
8411: 'UserPage' / 'StartPage' / 'ComputedPage' /
8412: 'Empty' /
8413: '(' [ MinMax ] CounterName CounterCond ')' /
8414: CondPage '(' CounterID ')' .
8415: NumParent = [ GreaterLess ] NParent .
8416: GreaterLess = '>' / '<' .
8417: NParent = NUMBER.
8418: CounterCond = '<' MaxCtrVal / '>' MinCtrVal /
8419: '=' EqCtrVal /
8420: 'IN' '[' ['-'] MinCtrBound '..'
8421: ['-'] MaxCtrBound ']' .
8422: PageCond = 'Even' / 'Odd' / 'One' .
8423: MaxCtrVal = NUMBER .
8424: MinCtrVal = NUMBER .
8425: EqCtrVal = NUMBER .
8426: MaxCtrBound = NUMBER .
8427: MinCtrBound = NUMBER .
1.1 cvs 8428:
8429: Rule = PresParam ';' / PresFunc ';' .
8430: PresParam = 'VertRef' ':' HorizPosition /
8431: 'HorizRef' ':' VertPosition /
8432: 'VertPos' ':' VPos /
8433: 'HorizPos' ':' HPos /
8434: 'Height' ':' Extent /
8435: 'Width' ':' Extent /
8436: 'VertOverflow' ':' Boolean /
8437: 'HorizOverflow' ':' Boolean /
8438: 'LineSpacing' ':' DistOrInherit /
8439: 'Indent' ':' DistOrInherit /
8440: 'Adjust' ':' AlignOrInherit /
8441: 'Justify' ':' BoolInherit /
8442: 'Hyphenate' ':' BoolInherit /
8443: 'PageBreak' ':' Boolean /
8444: 'LineBreak' ':' Boolean /
8445: 'InLine' ':' Boolean /
8446: 'NoBreak1' ':' AbsDist /
8447: 'NoBreak2' ':' AbsDist /
8448: 'Gather' ':' Boolean /
8449: 'Visibility' ':' NumberInherit /
8450: 'Size' ':' SizeInherit /
8451: 'Font' ':' NameInherit /
8452: 'Style' ':' StyleInherit /
8453: 'Underline' ':' UnderLineInherit /
8454: 'Thickness' ':' ThicknessInherit /
8455: 'Depth' ':' NumberInherit /
8456: 'LineStyle' ':' LineStyleInherit /
8457: 'LineWeight' ':' DistOrInherit /
8458: 'FillPattern' ':' NameInherit /
8459: 'Background' ':' NameInherit /
1.13 cvs 8460: 'Foreground' ':' NameInherit /
1.1 cvs 8461: 'Content' ':' VarConst .
8462: PresFunc = Creation '(' BoxID ')' /
8463: 'Line' /
8464: 'NoLine' /
8465: 'Page' '(' BoxID ')' /
1.13 cvs 8466: 'Copy' '(' BoxTypeToCopy ')' /
8467: 'ShowBox' /
1.18 ! cvs 8468: 'BackgroundPicture' ':' FileName /
! 8469: 'PictureMode' ':' PictMode .
1.1 cvs 8470:
8471: BoxTypeToCopy = BoxID [ ExtStruct ] /
8472: ElemID [ ExtStruct ] .
8473: ExtStruct = '(' ElemID ')' .
8474:
8475: Distance = [ Sign ] AbsDist .
8476: Sign = '+' / '-' .
8477: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
8478: [ Unit ] .
8479: IntegerOrAttr = IntegerPart / AttrID .
8480: IntegerPart = NUMBER .
8481: DecimalPart = NUMBER .
8482: Unit = 'em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
8483: 'pc' / 'px' / '%' .
8484:
8485: HPos = 'nil' / VertAxis '=' HorizPosition
8486: [ 'UserSpecified' ] .
8487: VPos = 'nil' / HorizAxis '=' VertPosition
8488: [ 'UserSpecified' ] .
8489: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
8490: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .
8491:
1.6 cvs 8492: VertPosition = Reference '.' HorizAxis [ Distance ] .
8493: HorizPosition = Reference '.' VertAxis [ Distance ] .
8494: Reference = 'Enclosing' [ BoxTypeNot ] /
8495: 'Enclosed' [ BoxTypeNot ] /
8496: 'Previous' [ BoxTypeNot ] /
8497: 'Next' [ BoxTypeNot ] /
8498: 'Referred' [ BoxTypeNot ] /
8499: 'Creator' /
8500: 'Root' /
8501: '*' /
8502: BoxOrType .
8503: BoxOrType = BoxID /
8504: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 8505: 'AnyElem' / 'AnyBox' /
8506: 'ElemWithAttr' AttrID .
1.6 cvs 8507: BoxTypeNot = [ 'NOT' ] BoxOrType .
8508:
8509: Extent = Reference '.' HeightWidth
8510: [ Relation ] [ 'Min' ] /
8511: AbsDist [ 'UserSpecified' ] [ 'Min' ] /
8512: HPos / VPos .
8513: HeightWidth = 'Height' / 'Width' .
8514: Relation = '*' ExtentAttr '%' / Distance .
8515: ExtentAttr = ExtentVal / AttrID .
8516: ExtentVal = NUMBER .
8517:
8518: Inheritance = Kinship InheritedValue .
8519: Kinship = 'Enclosing' / 'GrandFather'/ 'Enclosed' /
8520: 'Previous' / 'Creator' .
8521: InheritedValue = '+' PosIntAttr [ 'Max' maximumA ] /
8522: '-' NegIntAttr [ 'Min' minimumA ] /
8523: '=' .
8524: PosIntAttr = PosInt / AttrID .
8525: PosInt = NUMBER .
8526: NegIntAttr = NegInt / AttrID .
8527: NegInt = NUMBER .
8528: maximumA = maximum / AttrID .
8529: maximum = NUMBER .
8530: minimumA = minimum / AttrID .
8531: minimum = NUMBER .
8532:
8533: AlignOrInherit = Kinship '=' / Alignment .
8534: Alignment = 'Left' / 'Right' / 'VMiddle' /
8535: 'LeftWithDots' .
1.1 cvs 8536:
1.6 cvs 8537: DistOrInherit = Kinship InheritedDist / Distance .
8538: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .
1.1 cvs 8539:
1.6 cvs 8540: BoolInherit = Boolean / Kinship '=' .
8541: Boolean = 'Yes' / 'No' .
1.1 cvs 8542:
1.6 cvs 8543: NumberInherit = Integer / AttrID / Inheritance .
8544: Integer = NUMBER .
1.1 cvs 8545:
8546: LineStyleInherit= Kinship '=' / 'Solid' / 'Dashed' /
8547: 'Dotted' .
8548:
1.6 cvs 8549: SizeInherit = SizeAttr [ 'pt' ] / Kinship InheritedSize .
8550: InheritedSize = '+' SizeAttr [ 'pt' ]
8551: [ 'Max' MaxSizeAttr ] /
8552: '-' SizeAttr [ 'pt' ]
8553: [ 'Min' MinSizeAttr ] /
8554: '=' .
8555: SizeAttr = Size / AttrID .
8556: Size = NUMBER .
8557: MaxSizeAttr = MaxSize / AttrID .
8558: MaxSize = NUMBER .
8559: MinSizeAttr = MinSize / AttrID .
8560: MinSize = NUMBER .
8561:
8562: NameInherit = Kinship '=' / FontName .
8563: FontName = NAME .
8564: StyleInherit = Kinship '=' /
8565: 'Roman' / 'Bold' / 'Italics' /
8566: 'BoldItalics' / 'Oblique' / 'BoldOblique' .
1.1 cvs 8567: UnderLineInherit= Kinship '=' /
1.6 cvs 8568: 'NoUnderline' / 'Underlined' /
8569: 'Overlined' / 'CrossedOut' .
1.1 cvs 8570: ThicknessInherit= Kinship '=' / 'Thick' / 'Thin' .
1.13 cvs 8571:
8572: FileName = STRING .
8573: PictMode = 'NormalSize' / 'Scale' /
8574: 'RepeatXY' / 'RepeatX' / 'RepeatY' .
1.1 cvs 8575:
1.6 cvs 8576: VarConst = ConstID / ConstType ConstValue /
8577: VarID / '(' FunctionSeq ')' /
8578: ElemID .
8579:
8580: Creation = Create [ 'Repeated' ] .
8581: Create = 'CreateFirst' / 'CreateLast' /
8582: 'CreateBefore' / 'CreateAfter' /
8583: 'CreateEnclosing' .
8584:
8585: TransmitSeq = Transmit < Transmit > .
8586: Transmit = TypeOrCounter 'To' ExternAttr
8587: '(' ElemID ')' ';' .
8588: TypeOrCounter = CounterID / ElemID .
8589: ExternAttr = NAME .
1.1 cvs 8590:
1.18 ! cvs 8591: END</pre>
! 8592: </div>
1.1 cvs 8593:
1.18 ! cvs 8594: <div class="section">
1.1 cvs 8595:
1.18 ! cvs 8596: <h2><a name="sectb64">The T language</a></h2>
! 8597: <pre>TransSchema = 'TRANSLATION' ElemID ';'
1.1 cvs 8598: [ 'LINELENGTH' LineLength ';' ]
8599: [ 'LINEEND' CHARACTER ';' ]
8600: [ 'LINEENDINSERT' STRING ';' ]
8601: [ 'BUFFERS' BufferSeq ]
8602: [ 'COUNTERS' CounterSeq ]
8603: [ 'CONST' ConstSeq ]
8604: [ 'VAR' VariableSeq ]
8605: 'RULES' ElemSeq
8606: [ 'ATTRIBUTES' AttrSeq ]
8607: [ 'PRESENTATION' PresSeq ]
8608: < 'TEXTTRANSLATE' TextTransSeq >
8609: [ 'SYMBTRANSLATE' TransSeq ]
8610: [ 'GRAPHTRANSLATE' TransSeq ]
8611: 'END' .
8612:
8613: LineLength = NUMBER .
8614:
8615: BufferSeq = Buffer < Buffer > .
8616: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
8617: BufferID = NAME .
8618:
8619: CounterSeq = Counter < Counter > .
8620: Counter = CounterID [ ':' CounterFunc ] ';' .
8621: CounterID = NAME .
8622: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
8623: [ 'Init' AttrID ] /
8624: 'Rlevel' 'of' ElemID /
8625: 'Set' InitValue 'On' ElemID
8626: 'Add' Increment 'On' ElemID
8627: [ 'Init' AttrID ] .
8628: SLevelAsc = [ '-' ] LevelAsc .
8629: LevelAsc = NUMBER .
8630: InitValue = NUMBER .
8631: Increment = NUMBER .
8632: ElemID = NAME .
8633: AttrID = NAME .
8634:
8635: ConstSeq = Const < Const > .
8636: Const = ConstID '=' ConstValue ';' .
8637: ConstID = NAME .
8638: ConstValue = STRING .
8639:
8640: VariableSeq = Variable < Variable > .
8641: Variable = VarID ':' Function < Function > ';' .
8642: VarID = NAME .
8643: Function = 'Value' '(' CounterID [ ':' Length ]
8644: [ ',' CounterStyle ] ')' /
8645: 'FileDir' / 'FileName' / 'Extension' /
8646: 'DocumentName' / 'DocumentDir' /
8647: ConstID / CharString /
8648: BufferID / AttrID .
8649: Length = NUMBER .
8650: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
8651: 'Uppercase' / 'Lowercase' .
8652: CharString = STRING .
8653:
8654: ElemSeq = TransType < TransType > .
8655: TransType = [ FirstSec ] ElemID ':' RuleSeq .
8656: FirstSec = 'First' / 'Second' .
8657: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
8658: Rule = SimpleRule / ConditionBlock .
8659: ConditionBlock= 'IF' ConditionSeq SimpleRuleSeq .
8660: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
8661: SimpleRule .
8662:
8663: ConditionSeq = Condition [ 'AND' Condition ] .
8664: Condition = [ 'NOT' ] [ 'Target' ] Cond .
8665: Cond = CondElem / CondAscend .
8666: CondElem = 'FirstRef' / 'LastRef' /
8667: 'ExternalRef' /
8668: 'Defined' /
8669: 'Alphabet' '=' Alphabet /
8670: 'ComputedPage' / 'StartPage' /
8671: 'UserPage' / 'ReminderPage' /
8672: 'Empty' /
1.18 ! cvs 8673: ElemID /
1.1 cvs 8674: 'FirstAttr' / 'LastAttr' .
8675: CondAscend = [ Ascend ] CondOnAscend .
8676: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
8677: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
8678: CondRelLevel = NUMBER .
8679: CondOnAscend = 'First' / 'Last' /
8680: 'Referred' /
8681: [ 'Immediately' ] 'Within' [ NumParent ]
8682: ElemID [ ExtStruct ] /
8683: 'Attributes' /
8684: AttrID [ RelatAttr ] /
8685: 'Presentation' /
8686: PresRule /
8687: 'Comment' .
8688: NumParent = [ GreaterLess ] NParent .
8689: GreaterLess = '>' / '<' .
8690: NParent = NUMBER.
8691: Alphabet = NAME .
8692: RelatAttr = '=' Value /
8693: '>' [ '-' ] Minimum /
8694: '<' [ '-' ] Maximum /
8695: 'IN' '[' [ '-' ] MinInterval '..'
8696: [ '-' ] MaxInterval ']' .
8697: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
8698: Minimum = NUMBER .
8699: Maximum = NUMBER .
8700: MinInterval = NUMBER .
8701: MaxInterval = NUMBER .
8702: IntegerVal = NUMBER .
8703: TextVal = STRING .
8704: AttrValue = NAME .
8705:
8706: SimpleRule = 'Create' [ 'IN' VarID ] Object
8707: [ Position ] ';' /
8708: 'Write' Object [ Position ] ';' /
8709: 'Read' BufferID [ Position ] ';' /
8710: 'Include' File [ Position ] ';' /
1.6 cvs 8711: 'Get' [ RelPosition ] ElemID
8712: [ ExtStruct ]
8713: [ Position ] ';' /
1.1 cvs 8714: 'Copy' [ RelPosition ] ElemID
8715: [ ExtStruct ]
8716: [ Position ] ';' /
8717: 'Use' TrSchema [ 'For' ElemID ] ';' /
8718: 'Remove' ';' /
8719: 'NoTranslation' ';' /
8720: 'NoLineBreak' ';' /
8721: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 8722: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 8723: 'Set' CounterID InitValue [ Position ] ';' /
8724: 'Add' CounterID Increment [ Position ] ';' /
8725: 'Indent' [ 'IN' VarID ] [ IndentSign ]
8726: IndentValue [ Position ] ';' .
8727:
8728: IndentSign = '+' / '-' .
8729: IndentValue = NUMBER .
1.1 cvs 8730:
8731: Object = ConstID / CharString /
8732: BufferID /
8733: VarID /
8734: '(' Function < Function > ')' /
8735: AttrID /
8736: 'Value' /
8737: 'Content' /
8738: 'Comment' /
8739: 'Attributes' /
8740: 'Presentation' /
8741: 'RefId' /
8742: 'PairId' /
8743: 'FileDir' / 'FileName' / 'Extension' /
8744: 'DocumentName' / 'DocumentDir' /
8745: [ 'Referred' ] ReferredObject .
8746: Position = 'After' / 'Before' .
8747:
1.6 cvs 8748: ReferredObject= VarID /
8749: ElemID [ ExtStruct ] /
8750: 'RefId' /
8751: 'DocumentName' / 'DocumentDir' .
1.1 cvs 8752:
1.6 cvs 8753: File = FileName / BufferID .
8754: FileName = STRING .
1.1 cvs 8755:
1.6 cvs 8756: RelPosition = 'Included' / 'Referred' .
8757: ExtStruct = '(' ElemID ')' .
1.1 cvs 8758:
1.6 cvs 8759: TrSchema = NAME .
8760:
8761: AttrSeq = TransAttr < TransAttr > .
8762: TransAttr = AttrID [ '(' ElemID ')' ]
8763: [ RelatAttr ] ':' RuleSeq .
8764:
8765: PresSeq = PresTrans < PresTrans > .
8766: PresTrans = PresRule ':' RuleSeq .
8767: PresRule = 'Size' [ PresRelation ] /
8768: 'Indent' [ PresRelation ] /
8769: 'LineSpacing' [ PresRelation ] /
8770: 'Adjust' [ '=' AdjustVal ] /
8771: 'Justify' [ '=' BoolVal ] /
8772: 'Hyphenate' [ '=' BoolVal ] /
8773: 'Style' [ '=' StyleVal ] /
8774: 'Font' [ '=' FontVal ] /
8775: 'UnderLine' [ '=' UnderLineVal ] /
8776: 'Thickness' [ '=' ThicknessVal ] /
8777: 'LineStyle' [ '=' LineStyleVal ] /
8778: 'LineWeight' [ PresRelation ] /
8779: 'FillPattern' [ '=' Pattern ] /
8780: 'Background' [ '=' Color ] /
8781: 'Foreground' [ '=' Color ] .
8782:
8783: PresRelation = '=' PresValue /
8784: '>' [ '-' ] PresMinimum /
8785: '<' [ '-' ] PresMaximum /
8786: 'IN' '[' [ '-' ] PresIntervalMin '..'
8787: [ '-' ] PresIntervalMax ']' .
8788: AdjustVal = 'Left' / 'Right' / 'VMiddle' /
8789: 'LeftWithDots' .
8790: BoolVal = 'Yes' / 'No' .
8791: StyleVal = 'Bold' / 'Italics' / 'Roman' /
8792: 'BoldItalics' / 'Oblique' /
8793: 'BoldOblique' .
8794: FontVal = 'Times' / 'Helvetica' / 'Courier' .
8795: UnderLineVal = 'NoUnderline' / 'UnderLined' /
8796: 'OverLined' / 'CrossedOut' .
8797: ThicknessVal = 'Thick' / 'Thin' .
8798: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
8799: Pattern = NAME .
8800: Color = NAME .
8801: PresMinimum = NUMBER .
8802: PresMaximum = NUMBER .
1.1 cvs 8803: PresIntervalMin= NUMBER .
8804: PresIntervalMax= NUMBER .
1.6 cvs 8805: PresValue = [ '-' ] PresVal .
8806: PresVal = NUMBER .
1.1 cvs 8807:
1.6 cvs 8808: TextTransSeq = [ Alphabet ] TransSeq .
8809: Alphabet = NAME .
8810: TransSeq = 'BEGIN' < Translation > 'END' ';' /
8811: Translation .
8812: Translation = Source [ '->' Target ] ';' .
8813: Source = STRING .
1.18 ! cvs 8814: Target = STRING .</pre>
! 8815: </div>
! 8816: <hr>
! 8817: </div>
1.1 cvs 8818:
1.18 ! cvs 8819: <div class="chapter">
1.1 cvs 8820:
1.18 ! cvs 8821: <h1><a name="sect7">Character coding</a></h1>
1.1 cvs 8822:
1.18 ! cvs 8823: <div class="section">
1.1 cvs 8824:
1.18 ! cvs 8825: <h2><a name="sectb71">Characters</a></h2>
! 8826: <p>
1.1 cvs 8827: The characters of the Latin alphabet follow the encoding defined in the ISO
1.5 cvs 8828: 8859-1 (ISO Latin-1) standard. The characters of the Greek alphabet follow
1.18 ! cvs 8829: the encoding defined by Adobe for its Symbol font (Adobe FontSpecific).</p>
! 8830: <p>
1.1 cvs 8831: Characters whose octal code is greater than 0200 are written in the form of
8832: their octal code preceded by a backslash character (``\''). For example, the
1.18 ! cvs 8833: French word 'Résumé' is written <tt>R\351sum\351</tt>.</p>
! 8834: <p>
1.2 cvs 8835: To the ISO 8859-1 encoding four characters with the following codes have been
1.18 ! cvs 8836: added:<br>
! 8837: <tt>212</tt>: line break<br>
! 8838: <tt>240</tt>: sticky space<br>
! 8839: <tt>201</tt>: thin space<br>
! 8840: <tt>202</tt>: en space</p>
! 8841: <p>
! 8842: The <tt>212</tt> character is a ``line break'' character which forces a line
! 8843: break. The <tt>240</tt> character is a ``sticky space'', which cannot be
! 8844: replaced by a line break.</p>
! 8845: </div>
1.1 cvs 8846:
1.18 ! cvs 8847: <div class="section">
1.1 cvs 8848:
1.18 ! cvs 8849: <h2><a name="sectb72">Symbols</a></h2>
! 8850: <p>
1.1 cvs 8851: The table below gives the codes for the symbols of Thot. Symbols can be used
8852: in presentation schemas constants and in transcoding rules of translation
1.18 ! cvs 8853: schemas. Each symbol is represented by a single character.</p>
! 8854: <ul>
! 8855: <li>
! 8856: <tt>r</tt>: a radical
! 8857: <li>
! 8858: <tt>i</tt>: a simple integral
! 8859: <li>
! 8860: <tt>c</tt>: a curvilinear integral
! 8861: <li>
! 8862: <tt>d</tt>: a double integral
! 8863: <li>
! 8864: <tt>t</tt>: a triple integral
! 8865: <li>
! 8866: <tt>S</tt>: the summation symbol
! 8867: <li>
! 8868: <tt>P</tt>: the product symbol
! 8869: <li>
! 8870: <tt>U</tt>: the union symbol
! 8871: <li>
! 8872: <tt>I</tt>: the intersection symbol
! 8873: <li>
! 8874: <tt>></tt>: a right arrow
! 8875: <li>
! 8876: <tt><</tt>: a left arrow
! 8877: <li>
! 8878: <tt>^</tt>: an up arrow
! 8879: <li>
! 8880: <tt>V</tt>: a down arrow
! 8881: <li>
! 8882: <tt>(</tt>: an opening parenthesis
! 8883: <li>
! 8884: <tt>)</tt>: a closing parenthesis
! 8885: <li>
! 8886: <tt>{</tt>: an opening brace
! 8887: <li>
! 8888: <tt>}</tt>: a closing brace
! 8889: <li>
! 8890: <tt>[</tt>: an opening bracket
! 8891: <li>
! 8892: <tt>]</tt>: a closing bracket
! 8893: </ul>
! 8894: </div>
1.1 cvs 8895:
1.18 ! cvs 8896: <div class="section">
1.1 cvs 8897:
1.18 ! cvs 8898: <h2><a name="sectb73">Graphical elements</a></h2>
! 8899: <p>
1.1 cvs 8900: The table below gives the codes for the graphical elements of Thot. These
8901: elements can be used in presentation schemas constants and in transcoding
8902: rules of translation schemas. Each graphical element is represented by a
1.18 ! cvs 8903: single character.</p>
! 8904: <ul>
! 8905: <li>
! 8906: a: a circle
! 8907: <li><p>
! 8908: <tt>A</tt>: an open curve with an arrow head at the end</p>
! 8909: <li>
! 8910: <tt>b</tt>: a horizontal line along the lower side of the box
! 8911: <li>
! 8912: <tt>B</tt>: an open curve
! 8913: <li>
! 8914: <tt>c</tt>: an ellipse inscribed in the box
! 8915: <li>
! 8916: <tt>C</tt>: a rectangle with rounded corners
! 8917: <li>
! 8918: <tt>D</tt>: an open curve with two arrow heads
! 8919: <li>
! 8920: <tt>e</tt>: The northwest/southeast diagonal of the box with an arrowhead at
! 8921: the bottom
! 8922: <li>
! 8923: <tt>E</tt>: The southwest/northeast diagonal of the box with an arrowhead at
! 8924: the top
! 8925: <li>
! 8926: <tt>F</tt>: an open curve with an arrow head at start
! 8927: <li>
! 8928: <tt>h</tt>: a horizontal line as wide as the box and placed in its middle
! 8929: <li>
! 8930: <tt>l</tt>: a vertical line on the left side of the box
! 8931: <li>
! 8932: <tt>L</tt>: a lozenge
! 8933: <li>
! 8934: <tt>M</tt>: an open broken line with two arrow heads
! 8935: <li>
! 8936: <tt>N</tt>: an open broken line with an arrow head at start
! 8937: <li>
! 8938: <tt>o</tt>: The southwest/northeast diagonal of the box with an arrowhead at
! 8939: the bottom
! 8940: <li>
! 8941: <tt>O</tt>: The northwest/southeast diagonal of the box with an arrowhead at
! 8942: the top
! 8943: <li>
! 8944: <tt>p</tt>: a polygon
! 8945: <li>
! 8946: <tt>P</tt>: a rectangle with round corners and a horizontal bar at the top
! 8947: <li>
! 8948: <tt>Q</tt>: an ellipse with a horizontal bar at the top
! 8949: <li>
! 8950: <tt>r</tt>: a vertical line on the right side of the box
! 8951: <li>
! 8952: <tt>R</tt>: a rectangle which is the shape of the box
! 8953: <li>
! 8954: <tt>s</tt>: a closed curve
! 8955: <li>
! 8956: <tt>S</tt>: an open broken line
! 8957: <li>
! 8958: <tt>t</tt>: a horizontal line along the upper side of the box
! 8959: <li>
! 8960: <tt>U</tt>: an open broken line with an arrow head at the end
! 8961: <li>
! 8962: <tt>v</tt>: a vertical line as tall as the box and placed in its middle
! 8963: <li>
! 8964: <tt>V</tt>: a down arrow as tall as the box and in its middle
! 8965: <li>
! 8966: w: a segment (2 points)
! 8967: <li>
! 8968: <tt>W</tt>: the upper right corner
! 8969: <li>
! 8970: x: a segment (2 points) with an arrow head at the end
! 8971: <li>
! 8972: <tt>X</tt>: the lower right corner
! 8973: <li>
! 8974: y: a segment (2 points) with an arrow head at the end
! 8975: <li>
! 8976: <tt>Y</tt>: the lower left corner
! 8977: <li>
! 8978: z: a segment (2 points) with an arrow head at the end
! 8979: <li>
! 8980: <tt>Z</tt>: the upper left corner
! 8981: <li>
! 8982: <tt>space</tt>: a transparent element
! 8983: <li>
! 8984: <tt>^</tt>: an up arrow as tall as the box and in its middle
! 8985: <li>
! 8986: <tt>></tt>: a right arrow as long as the box's width and in its middle
! 8987: <li>
! 8988: <tt>></tt>: a left arrow as long as the box's width and in its middle
! 8989: <li>
! 8990: <tt>/</tt>: The southwest/northeast diagonal of the box
! 8991: <li>
! 8992: <tt>\</tt>: the northwest/southeast diagonal of the box
! 8993: </ul>
! 8994: <hr>
! 8995: </div>
! 8996: </div>
! 8997: </body>
! 8998: </html>
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