Annotation of Amaya/doc/languages.html, revision 1.37
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1.30 cvs 6: <title>The Languages of Thot</title>
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1.19 cvs 12: <div class="frontmatter" align="center">
1.18 cvs 13: <h1>The Languages of Thot</h1>
14:
15: <h3>Vincent Quint</h3>
16:
17: <h4>Translated from French by Ethan Munson</h4>
18:
1.37 ! cvs 19: <h4>Version of April 16, 2001</h4>
1.30 cvs 20:
1.37 ! cvs 21: <p>© 1996-2001 INRIA</p>
! 22: <hr />
1.18 cvs 23: </div>
24:
25: <div class="tableofcontents">
26: <h2><a href="languages.toc.html">Contents</a></h2>
27: <ul>
1.37 ! cvs 28: <li><big><a href="#sect2">The document model of Thot</a></big>
1.30 cvs 29: <ul>
30: <li><strong><a href="#sectb21">The logical structure of
31: documents</a></strong></li>
32: <li><strong><a href="#sectb22">Generic and specific
33: structures</a></strong></li>
34: <li><strong><a href="#sectb23">Logical structure and physical
35: structure</a></strong></li>
36: <li><strong><a href="#sectb24">Document structures and object
37: structures</a></strong></li>
38: </ul>
39: </li>
1.37 ! cvs 40: <li><big><a href="#sect3">The S language</a></big>
1.30 cvs 41: <ul>
1.37 ! cvs 42: <li><strong><a href="#sectb31">Document meta-structure</a></strong>
1.30 cvs 43: <ul>
44: <li><a href="#sectc311">The basic types</a></li>
45: <li><a href="#sectc312">Constructed elements</a></li>
1.37 ! cvs 46: <li><a href="#sectc313">Logical structure constructors</a>
1.30 cvs 47: <ul>
48: <li><small><a href="#sectd3131">Aggregate and
49: List</a></small></li>
50: <li><small><a href="#sectd3132">Choice, Schema, and
51: Unit</a></small></li>
52: <li><small><a href="#sectd3133">Reference and
53: Inclusion</a></small></li>
54: <li><small><a href="#sectd3134">Mark pairs</a></small></li>
55: <li><small><a href="#sectd3135">Restrictions and
56: Extensions</a></small></li>
57: <li><small><a href="#sectd3136">Summary</a></small></li>
58: </ul>
59: </li>
60: <li><a href="#sectc315">Attributes</a></li>
61: <li><a href="#sectc316">Discussion of the model</a></li>
62: </ul>
63: </li>
64: <li><strong><a href="#sectb32">The definition language for generic
1.37 ! cvs 65: structures</a></strong>
1.30 cvs 66: <ul>
67: <li><a href="#sectc321">Writing Conventions</a></li>
68: <li><a href="#sectc322">Extension schemas</a></li>
69: <li><a href="#sectc323">The general organization of structure
70: schemas</a></li>
71: <li><a href="#sectc324">The default presentation</a></li>
72: <li><a href="#sectc325">Global Attributes</a></li>
73: <li><a href="#sectc327">Structured elements</a></li>
1.37 ! cvs 74: <li><a href="#sectc328">Structure definitions</a>
1.30 cvs 75: <ul>
76: <li><small><a href="#sectd3281">List</a></small></li>
77: <li><small><a href="#sectd3282">Aggregate</a></small></li>
78: <li><small><a href="#sectd3283">Choice</a></small></li>
79: <li><small><a href="#sectd3284">Reference</a></small></li>
80: <li><small><a href="#sectd3285">Mark pairs</a></small></li>
81: </ul>
82: </li>
83: <li><a href="#sectc329">Imports</a></li>
84: <li><a href="#sectc3210">Extension rules</a></li>
85: <li><a href="#sectc3212">Units</a></li>
86: <li><a href="#sectc3213">Skeleton elements</a></li>
87: <li><a href="#sectc3214">Exceptions</a></li>
88: </ul>
89: </li>
1.37 ! cvs 90: <li><strong><a href="#sectb33">Some examples</a></strong>
1.30 cvs 91: <ul>
92: <li><a href="#sectc331">A class of documents: articles</a></li>
93: <li><a href="#sectc332">A class of objects: mathematical
94: formulas</a></li>
95: </ul>
96: </li>
97: </ul>
98: </li>
1.37 ! cvs 99: <li><big><a href="#sect4">The P language</a></big>
1.30 cvs 100: <ul>
1.37 ! cvs 101: <li><strong><a href="#sectb41">Document presentation</a></strong>
1.30 cvs 102: <ul>
103: <li><a href="#sectc411">Two levels of presentation</a></li>
104: <li><a href="#sectc412">Boxes</a></li>
105: <li><a href="#sectc413">Views and visibility</a></li>
106: <li><a href="#sectc414">Pages</a></li>
107: <li><a href="#sectc415">Numbering</a></li>
1.34 cvs 108: <li><a href="#sectc416">Presentation properties</a></li>
1.30 cvs 109: </ul>
110: </li>
111: <li><strong><a href="#sectb42">Presentation description
1.37 ! cvs 112: language</a></strong>
1.30 cvs 113: <ul>
114: <li><a href="#sectc421">The organization of a presentation
115: schema</a></li>
116: <li><a href="#sectc422">Views</a></li>
117: <li><a href="#sectc423">Print Views</a></li>
118: <li><a href="#sectc424">Counters</a></li>
119: <li><a href="#sectc425">Presentation constants</a></li>
120: <li><a href="#sectc426">Variables</a></li>
121: <li><a href="#sectc427">Default presentation rules</a></li>
122: <li><a href="#sectc428">Presentation and page layout boxes</a></li>
123: <li><a href="#sectc429">Presentation of structured elements</a></li>
124: <li><a href="#sectc4210">Logical attribute presentation</a></li>
125: <li><a href="#sectc4212">Value transmission rules</a></li>
126: <li><a href="#sectc4213">Presentation rules</a></li>
127: <li><a href="#sectc4214">Conditions applying to presentation
1.37 ! cvs 128: rules</a>
1.30 cvs 129: <ul>
1.37 ! cvs 130: <li><small><a href="#sectd42141">Conditions based on the
! 131: logical position of the element</a></small></li>
1.30 cvs 132: <li><small><a href="#sectd42142">Conditions on
133: references</a></small></li>
134: <li><small><a href="#sectd42143">Conditions on logical
135: attributes</a></small></li>
136: <li><small><a href="#sectd42144">Conditions on page
137: breaks</a></small></li>
138: <li><small><a href="#sectd42145">Conditions on the element's
139: content</a></small></li>
140: <li><small><a href="#sectd42146">Conditions on
141: counters</a></small></li>
142: </ul>
143: </li>
144: <li><a href="#sectc4215">A presentation rule</a></li>
145: <li><a href="#sectc4216">Box axes</a></li>
146: <li><a href="#sectc4217">Distance units</a></li>
147: <li><a href="#sectc4218">Relative positions</a></li>
1.37 ! cvs 148: <li><a href="#sectc4219">Box extents</a>
1.30 cvs 149: <ul>
150: <li><small><a href="#sectd42191">Fixed extents</a></small></li>
151: <li><small><a href="#sectd42192">Relative
152: extents</a></small></li>
153: <li><small><a href="#sectd42193">Elastic
154: extents</a></small></li>
155: </ul>
156: </li>
157: <li><a href="#sectc4220">Overflow</a></li>
158: <li><a href="#sectc4221">Inheritance</a></li>
1.37 ! cvs 159: <li><a href="#sectc4222">Line breaking</a>
1.30 cvs 160: <ul>
161: <li><small><a href="#sectd42221">Line spacing</a></small></li>
162: <li><small><a href="#sectd42222">First line
163: indentation</a></small></li>
164: <li><small><a href="#sectd42223">Alignment</a></small></li>
165: <li><small><a href="#sectd42225">Hyphenation</a></small></li>
166: <li><small><a href="#sectd42226">Avoiding line
167: breaking</a></small></li>
168: </ul>
169: </li>
170: <li><a href="#sectc4223">Page breaking and line breaking
171: conditions</a></li>
172: <li><a href="#sectc4224">Visibility</a></li>
1.37 ! cvs 173: <li><a href="#sectc4225">Character style properties</a>
1.30 cvs 174: <ul>
175: <li><small><a href="#sectd42251">Character size</a></small></li>
176: <li><small><a href="#sectd42252">Font and character
177: style</a></small></li>
178: <li><small><a href="#sectd42253">Underlining</a></small></li>
179: </ul>
180: </li>
181: <li><a href="#sectc4226">Stacking order</a></li>
182: <li><a href="#sectc4227">Line style</a></li>
183: <li><a href="#sectc4228">Line thickness</a></li>
184: <li><a href="#sectc4229">Fill pattern</a></li>
185: <li><a href="#sectc4230">Colors</a></li>
186: <li><a href="#sectc4230a">Background color and border</a></li>
187: <li><a href="#sectc4230b">Background pictures</a></li>
188: <li><a href="#sectc4231">Presentation box content</a></li>
189: <li><a href="#sectc4232">Presentation box creation</a></li>
190: <li><a href="#sectc4233">Page layout</a></li>
191: <li><a href="#sectc4234">Box copies</a></li>
192: </ul>
193: </li>
194: </ul>
195: </li>
1.37 ! cvs 196: <li><big><a href="#sect5">The T language</a></big>
1.30 cvs 197: <ul>
1.37 ! cvs 198: <li><strong><a href="#sectb51">Document translation</a></strong>
1.30 cvs 199: <ul>
200: <li><a href="#sectc511">Translation principles</a></li>
201: <li><a href="#sectc512">Translation procedure</a></li>
202: </ul>
203: </li>
204: <li><strong><a href="#sectb52">Translation definition
1.37 ! cvs 205: language</a></strong>
1.30 cvs 206: <ul>
207: <li><a href="#sectc521">Organization of a translation
208: schema</a></li>
209: <li><a href="#sectc522">Line length</a></li>
210: <li><a href="#sectc523">Buffers</a></li>
211: <li><a href="#sectc524">Counters</a></li>
212: <li><a href="#sectc525">Constants</a></li>
213: <li><a href="#sectc526">Variables</a></li>
214: <li><a href="#sectc527">Translating structure elements</a></li>
1.37 ! cvs 215: <li><a href="#sectc528">Conditional rules</a>
1.30 cvs 216: <ul>
217: <li><small><a href="#sectd5281">Conditions based on the logical
218: position of the element</a></small></li>
219: <li><small><a href="#sectd5282">Conditions on
220: references</a></small></li>
221: <li><small><a href="#sectd5284">Conditions on the
222: alphabets</a></small></li>
223: <li><small><a href="#sectd5285">Conditions on page
224: breaks</a></small></li>
225: <li><small><a href="#sectd5286">Conditions on the element's
226: content</a></small></li>
227: <li><small><a href="#sectd5288">Conditions on the presence of
228: specific presentation rules</a></small></li>
229: <li><small><a href="#sectd5289">Conditions on the presence of
230: logical attributes</a></small></li>
231: <li><small><a href="#sectd52810">Conditions on logical
232: attributes</a></small></li>
233: <li><small><a href="#sectd52811">Conditions on specific
234: presentation rules</a></small></li>
235: </ul>
236: </li>
237: <li><a href="#sectc529">Translation rules</a></li>
238: <li><a href="#sectc5210">The <tt>Create</tt> rule</a></li>
239: <li><a href="#sectc5211">The <tt>Write</tt> rule</a></li>
240: <li><a href="#sectc5212">The <tt>Read</tt> rule</a></li>
241: <li><a href="#sectc5213">The <tt>Include</tt> rule</a></li>
242: <li><a href="#sectc5214">The <tt>Get</tt> rule</a></li>
243: <li><a href="#sectc5215">The <tt>Copy</tt> rule</a></li>
244: <li><a href="#sectc5216">The <tt>Use</tt> rule</a></li>
245: <li><a href="#sectc5217">The <tt>Remove</tt> rule</a></li>
1.31 cvs 246: <li><a href="#sectc5217a">The <code>Ignore</code> rule</a></li>
1.30 cvs 247: <li><a href="#sectc5218">The <tt>NoTranslation</tt> rule</a></li>
248: <li><a href="#sectc5219">The <tt>NoLineBreak</tt> rule</a></li>
249: <li><a href="#sectc5220">The <tt>ChangeMainFile</tt> rule</a></li>
250: <li><a href="#sectc5220a">The <tt>RemoveFile</tt> rule</a></li>
251: <li><a href="#sectc5221">The <tt>Set</tt> and <tt>Add</tt>
252: rules</a></li>
253: <li><a href="#sectc5221a">The <tt>Indent</tt> rule</a></li>
254: <li><a href="#sectc5222">Rule application order</a></li>
255: <li><a href="#sectc5223">Translation of logical attributes</a></li>
256: <li><a href="#sectc5224">Translation of specific
257: presentations</a></li>
258: <li><a href="#sectc5225">Recoding of characters, symbols and
259: graphics</a></li>
260: </ul>
261: </li>
262: </ul>
263: </li>
1.37 ! cvs 264: <li><big><a href="#sect6">Language grammars</a></big>
1.30 cvs 265: <ul>
266: <li><strong><a href="#sectb61">The M meta-language</a></strong></li>
267: <li><strong><a href="#sectb62">The S language</a></strong></li>
268: <li><strong><a href="#sectb63">The P language</a></strong></li>
269: <li><strong><a href="#sectb64">The T language</a></strong></li>
270: </ul>
271: </li>
1.37 ! cvs 272: <li><big><a href="#sect7">Character coding</a></big>
1.30 cvs 273: <ul>
274: <li><strong><a href="#sectb71">Characters</a></strong></li>
275: <li><strong><a href="#sectb72">Symbols</a></strong></li>
276: <li><strong><a href="#sectb73">Graphical elements</a></strong></li>
277: </ul>
278: </li>
1.18 cvs 279: </ul>
1.37 ! cvs 280: <hr />
1.18 cvs 281: </div>
1.1 cvs 282:
1.18 cvs 283: <div class="chapter">
1.37 ! cvs 284: <h1><a name="sect2" id="sect2">The document model of Thot</a></h1>
1.1 cvs 285:
1.30 cvs 286: <p>All of the services which Thot provides to the user are based on the
1.37 ! cvs 287: system's internal document representation. This representation is itself
! 288: derived from the document model which underlies Thot. The model is presented
1.30 cvs 289: here, prior to the description of the languages which permit the generic
290: specification of documents.</p>
1.1 cvs 291:
1.18 cvs 292: <div class="section">
1.37 ! cvs 293: <h2><a name="sectb21" id="sectb21">The logical structure of documents</a></h2>
1.1 cvs 294:
1.30 cvs 295: <p>The document model of Thot is primarily designed to allow the user to
296: operate on those entities which s/he has in mind when s/he works on a
297: document. The model makes no assumptions about the nature of these entities.
298: It is essentially these logical entities, such as paragraphs, sections,
299: chapters, notes, titles, and cross-references which give a document its
300: logical structure.</p>
301:
302: <p>Because of this model, the author can divide the document into chapters,
1.37 ! cvs 303: giving each one a title. The content of these chapters can be further divided
! 304: into sections, subsections, etc. The text is organized into successive
1.2 cvs 305: paragraphs, according to the content. In the writing phase, the lines, pages,
1.37 ! cvs 306: margins, spacing, fonts, and character styles are not very important. In
! 307: fact, if the system requires documents to be written in these terms, it gets
! 308: in the way. So, Thot's model is primarily based on the logical aspect of
! 309: documents. The creation of a model of this type essentially requires the
! 310: definition :</p>
1.18 cvs 311: <ul>
1.30 cvs 312: <li>of the entities which can appear in the documents,</li>
313: <li>and the relations between these entities.</li>
1.18 cvs 314: </ul>
1.30 cvs 315:
1.37 ! cvs 316: <p>The choice of entities to include in the model can be subtle. Some
! 317: documents require chapters, while others only need various levels of
! 318: sections. Certain documents contain appendices, others don't. In different
! 319: documents the same logical entity may go by different names (e.g.
! 320: ``Conclusion'' and ``Summary''). Certain entities which are absolutely
! 321: necessary in some documents, such as clauses in a contract or the address of
! 322: the recipient in a letter, are useless in most other cases.</p>
1.30 cvs 323:
324: <p>The differences between documents result from more than just the entities
325: that appear in them, but also from the relationships between these entities
1.37 ! cvs 326: and the ways that they are linked. In certain documents, notes are spread
1.30 cvs 327: throughout the document, for example at the bottom of the page containing the
1.1 cvs 328: cross-reference to them, while in other documents they are collected at the
1.37 ! cvs 329: end of each chapter or even at the end of the work. As another example, the
1.1 cvs 330: introduction of some documents can contain many sections, while in other
331: documents, the introduction is restricted to be a short sequence of
1.18 cvs 332: paragraphs.</p>
1.30 cvs 333:
1.37 ! cvs 334: <p>All of this makes it unlikely that a single model can describe any
! 335: document at a relatively high level. It is obviously tempting to make up a
! 336: list of widely used entities, such as chapters, sections, paragraphs, and
! 337: titles, and then map all other entities onto the available choices. In this
! 338: way, an introduction can be supported as a chapter and a contract clause
! 339: supported as a paragraph or section. However, in trying to widen the range of
! 340: usage of certain entities, their meaning can be lost and the power of the
! 341: model reduced. In addition, while this widening partially solves the problem
! 342: of choosing entities, it does not solve the problem of their organization:
! 343: when a chapter must be composed of sections, how does one indicate that an
! 344: introduction has none when it is merely another chapter? One solution is to
1.1 cvs 345: include introductions in the list of supported entities. But then, how does
346: one distinguish those introductions which are allowed to have sections from
1.37 ! cvs 347: those which are not. Perhaps this could be done by defining two types of
1.1 cvs 348: introduction. Clearly, this approach risks an infinite expansion of the list
1.18 cvs 349: of widely used entities.</p>
350: </div>
1.1 cvs 351:
1.18 cvs 352: <div class="section">
1.37 ! cvs 353: <h2><a name="sectb22" id="sectb22">Generic and specific structures</a></h2>
1.1 cvs 354:
1.30 cvs 355: <p>Thus, it is apparently impossible to construct an exhaustive inventory of
356: all those entities which are necessary and sufficient to precisely describe
1.37 ! cvs 357: any document. It also seems impossible to specify all possible arrangements
! 358: of these entities in a document. This is why Thot uses a <em>meta-model</em>
1.18 cvs 359: instead, which permits the description of numerous <em>models</em>, each one
360: describing a <em>class</em> of documents.</p>
1.30 cvs 361:
1.37 ! cvs 362: <p>A <em>class</em> is a set of documents having very similar structure.
! 363: Thus, the collection of research reports published by a laboratory
! 364: constitutes a class; the set of commercial proposals by the sales department
! 365: of a company constitutes another class; the set of articles published by a
! 366: journal constitutes a third class. Clearly, it is not possible to enumerate
! 367: every possible document class. It is also clear that new document classes
! 368: must be created to satisfy new needs and applications.</p>
1.30 cvs 369:
370: <p>To give a more rigorous definition of classes, we must introduce the ideas
1.37 ! cvs 371: of <em>generic structure</em> and <em>specific structure</em>. Each document
1.30 cvs 372: has a <em>specific structure</em> which organizes the various parts which
1.37 ! cvs 373: comprise it. We illustrate this with the help of a simple example comparing
1.30 cvs 374: two reports, A and B (<a href="#specstruct">see Figure</a>). The report A
1.37 ! cvs 375: contains an introduction followed by three chapters and a conclusion. The
! 376: first chapter contains two sections, the second, three sections. That is the
1.18 cvs 377: <em>specific</em> structure of document A. Similarly, the structure of
1.1 cvs 378: document B is: an introduction, two chapters, a conclusion; Chapter 1 has
1.37 ! cvs 379: three sections while Chapter 2 has four. The specific structures of these two
1.18 cvs 380: documents are thus different.</p>
1.1 cvs 381:
1.18 cvs 382: <div class="figure">
1.37 ! cvs 383: <hr />
1.18 cvs 384: <pre> Report A Report B
1.1 cvs 385: Introduction Introduction
386: Chapter 1 Chapter 1
387: Section 1.1 Section 1.1
388: Section 1.2 Section 1.2
389: Chapter 2 Section 1.3
390: Section 2.1 Chapter 2
391: Section 2.2 Section 2.1
392: Section 2.3 Section 2.2
393: Chapter 3 Section 2.3
394: Conclusion Section 2.4
1.18 cvs 395: Conclusion</pre>
1.30 cvs 396:
1.37 ! cvs 397: <p align="center"><em><a name="specstruct" id="specstruct">Two specific
1.30 cvs 398: structures</a></em></p>
1.37 ! cvs 399: <hr />
1.30 cvs 400: </div>
401:
402: <p>The <em>generic structure</em> defines the ways in which specific
1.37 ! cvs 403: structures can be constructed. It specifies how to generate specific
! 404: structures. The reports A and B, though different, are constructed in
1.30 cvs 405: accordance with the same generic structure, which specifies that a report
406: contains an introduction followed by a variable number of chapters and a
407: conclusion, with each chapter containing a variable number of sections.</p>
408:
409: <p>There is a one-to-one correspondence between a class and a generic
1.37 ! cvs 410: structure: all the documents of a class are constructed in accordance with
! 411: the same generic structure. Hence the definition of the class: a class is a
! 412: set of documents whose specific structure is constructed in accordance with
! 413: the same generic structure. A class is characterized by its generic
1.30 cvs 414: structure.</p>
1.19 cvs 415:
1.30 cvs 416: <p>Thus, a generic structure can be considered to be a model at the level
1.37 ! cvs 417: which interests us, but only for one class of documents. When the definition
1.30 cvs 418: is limited to a single class of documents, it is possible to define a model
419: which does a good job of representing the documents of the class, including
1.37 ! cvs 420: the necessary entities and unencumbered by useless entities. The description
1.30 cvs 421: of the organization of the documents in the class can then be sufficiently
1.18 cvs 422: precise.</p>
423: </div>
1.1 cvs 424:
1.18 cvs 425: <div class="section">
1.37 ! cvs 426: <h2><a name="sectb23" id="sectb23">Logical structure and physical
! 427: structure</a></h2>
1.1 cvs 428:
1.30 cvs 429: <p>Generic structures only describe the <em>logical</em> organization of
1.18 cvs 430: documents, not their <em>physical</em> presentation on a screen or on sheets
1.37 ! cvs 431: of paper. However, for a document to be displayed or printed, its graphic
1.18 cvs 432: presentation must be taken into account.</p>
1.30 cvs 433:
434: <p>An examination of current printed documents shows that the details of
1.1 cvs 435: presentation essentially serve to bring out their logical structure. Outside
436: of some particular domains, notably advertising, the presentation is rarely
1.37 ! cvs 437: independent of the logical organization of the text. Moreover, the art of
1.1 cvs 438: typography consists of enhancing the organization of the text being set,
1.37 ! cvs 439: without catching the eye of the reader with overly pronounced effects. Thus,
! 440: italic and boldface type are used to emphasize words or expressions which
! 441: have greater significance than the rest of the text: keywords, new ideas,
! 442: citations, book titles, etc. Other effects highlight the organization of the
1.1 cvs 443: text: vertical space, margin changes, page breaks, centering, eventually
444: combined with the changes in the shapes or weight of the characters. These
445: effects serve to indicate the transitions between paragraphs, sections, or
446: chapters: an object's level in the logical structure of the document is shown
1.18 cvs 447: by the markedness of the effects.</p>
1.30 cvs 448:
449: <p>Since the model permits the description of all of the logical structure of
450: the document, the presentation can be derived from the model without being
1.37 ! cvs 451: submerged in the document itself. It suffices to use the logical structure of
1.1 cvs 452: the document to make the desired changes in its presentation: changes in type
1.18 cvs 453: size, type style, spacing, margin, centering, etc.</p>
1.30 cvs 454:
455: <p>Just as one cannot define a unique generic logical structure for all
456: document classes, one cannot define universal presentation rules which can be
1.37 ! cvs 457: applied to all document classes. For certain types of documents the chapter
! 458: titles will be centered on the page and printed in large, bold type. For
! 459: other documents, the same chapter titles will be printed in small, italic
! 460: type and aligned on the left margin.</p>
1.30 cvs 461:
462: <p>Therefore, it is necessary to base the presentation specifications for
1.37 ! cvs 463: documents on their class. Such a specification can be very fine-grained,
1.1 cvs 464: because the presentation is expressed in terms of the entities defined in the
1.37 ! cvs 465: generic logical structure of the class. Thus, it is possible to specify a
1.1 cvs 466: different presentation for the chapter titles and the section titles, and
467: similarly to specify titles for the sections according to their level in the
1.37 ! cvs 468: section hierarchy. The set of rules which specify the presentation of all the
1.18 cvs 469: elements defined in a generic logical structure is called a <em>generic
470: presentation</em>.</p>
1.30 cvs 471:
472: <p>There are several advantages derived from having a presentation linked to
473: the generic structure and described by a generic presentation. Homogeneity is
1.37 ! cvs 474: the first. Since every document in a class corresponds to the same generic
1.1 cvs 475: logical structure, a homogenous presentation for different documents of the
476: same class can be assured by applying the same generic presentation to all
1.37 ! cvs 477: documents of the class. Homogeneity of presentation can also be found among
! 478: the entities of a single document: every section heading will be presented in
! 479: the same way, the first line of every paragraph of the same type will have
! 480: the same indentation, etc.</p>
1.30 cvs 481:
482: <p>Another advantage of this approach to presentation is that it facilitates
1.37 ! cvs 483: changes to the graphical aspect of documents. A change to the generic
! 484: presentation rules attached to each type of entity will alter the
! 485: presentation of the entire document, and will do so homogenously. In this
! 486: case, the internal homogeneity of the class is no longer assured, but the way
! 487: to control it is simple. It suffices to adopt a single generic presentation
! 488: for the entire class.</p>
1.30 cvs 489:
490: <p>If the presentation of the class does not have to be homogenous, then the
1.37 ! cvs 491: appearance of the document can be adapted to the way it will be used or to
! 492: the device used to render it. This quality is sufficient to allow the
! 493: existence of <a name="mulpres" id="mulpres">many generic presentations</a>
! 494: for the same document class. By applying one or the other of these
! 495: presentations to it, the document can be seen under different graphical
! 496: aspects. It must be emphasized that this type of modification of the
! 497: presentation is not a change to the document itself (in its specific logical
! 498: structure or its content), but only in its appearance at the time of editing
! 499: or printing.</p>
1.18 cvs 500: </div>
1.1 cvs 501:
1.18 cvs 502: <div class="section">
1.37 ! cvs 503: <h2><a name="sectb24" id="sectb24">Document structures and object
! 504: structures</a></h2>
1.1 cvs 505:
1.30 cvs 506: <p>So far, we have only discussed the global structure of documents and have
1.37 ! cvs 507: not considered the contents found in that structure. We could limit ourselves
1.30 cvs 508: to purely textual contents by assuming that a title or a paragraph contains a
1.37 ! cvs 509: simple linear text. But this model would be too restrictive. In fact, certain
! 510: documents contain not only text, but also contain tables, diagrams,
! 511: photographs, mathematical formulas, and program fragments. The model must
1.18 cvs 512: permit the representation of such <em>objects</em>.</p>
1.30 cvs 513:
514: <p>Just as with the whole of the document, the model takes into account the
1.37 ! cvs 515: logical structure of objects of this type. Some are clearly structured,
! 516: others are less so. Logical structure can be recognized in mathematical
! 517: formulas, in tables, and in certain types of diagrams. On the other hand, it
! 518: is difficult to define the structure of a photograph or of some drawings. But
1.1 cvs 519: in any case, it does not seem possible to define one unique structure which
1.37 ! cvs 520: can represent every one of these types of objects. The approach taken in the
1.1 cvs 521: definition of meta-structure and document classes also applies to objects.
522: Object classes can be defined which put together objects of similar type,
1.18 cvs 523: constructed from the same generic logical structure.</p>
1.30 cvs 524:
525: <p>Thus, a mathematical class can be defined and have a generic logical
1.37 ! cvs 526: structure associated with it. But even if a single generic structure can
1.30 cvs 527: represent a sufficient variety of mathematical formulas, for other objects
1.37 ! cvs 528: with less rigorous structure, multiple classes must be defined. As for
! 529: documents, using multiple classes assures that the model can describe the
! 530: full range of objects to be presented. It also permits the system to support
! 531: objects which were not initially anticipated. Moreover, this comment applies
1.30 cvs 532: equally to mathematics: different classes of formulas can be described
533: depending on the domain of mathematics being described.</p>
534:
535: <p>Since objects have the same level of logical representation as documents,
1.37 ! cvs 536: they gain the same advantages. In particular, it is possible to define the
1.1 cvs 537: presentation separately from the objects themselves and attach it to the
1.37 ! cvs 538: class. Thus, as for documents, objects of the same type have a uniform
1.1 cvs 539: presentation and the presentation of every object in a given class can be
1.37 ! cvs 540: changed simply by changing the generic presentation of the class. Another
1.1 cvs 541: advantage of using this document model is that the system does not bother the
542: user with the details of presentation, but rather allows the user to
1.18 cvs 543: concentrate on the logical aspect of the document and the objects.</p>
1.30 cvs 544:
545: <p>It is clear that the documents in a class do not necessarily use the same
1.1 cvs 546: classes of objects: one technical report will contain tables while another
547: report will have no tables but will use mathematical formulas. The usable
1.2 cvs 548: object classes are not always mentioned in a limiting way in the generic
1.37 ! cvs 549: logical structure of documents. Rather, they can be chosen freely from a
1.18 cvs 550: large set, independent of the document class.</p>
1.30 cvs 551:
552: <p>Thus, the object classes will be made commonplace and usable in every
1.1 cvs 553: document. The notion of ``object'' can be enlarged to include not only
554: non-textual elements, but also certain types of textual elements which can
1.37 ! cvs 555: appear in practically every document, whatever their class. Among these
1.2 cvs 556: textual elements, one can mention enumerations, descriptions, examples,
1.18 cvs 557: quotations, even paragraphs.</p>
1.30 cvs 558:
559: <p>Thus, the document model is not a single, general model describing every
1.37 ! cvs 560: type of document in one place. Rather, it is a meta-model which can be used
1.30 cvs 561: to describe many different models each of which represents either a class of
1.1 cvs 562: similar documents or a class of similar objects which every document can
1.18 cvs 563: include.</p>
564: </div>
1.37 ! cvs 565: <hr />
1.18 cvs 566: </div>
1.1 cvs 567:
1.18 cvs 568: <div class="chapter">
1.37 ! cvs 569: <h1><a name="sect3" id="sect3">The S language</a></h1>
1.1 cvs 570:
1.18 cvs 571: <div class="section">
1.37 ! cvs 572: <h2><a name="sectb31" id="sectb31">Document meta-structure</a></h2>
1.1 cvs 573:
1.30 cvs 574: <p>Since the concept of meta-structure is well suited to the task of
575: describing documents at a high level of abstraction, this meta-structure must
1.37 ! cvs 576: be precisely defined. Toward that end this section first presents the basic
1.1 cvs 577: elements from which documents and structured objects are composed and then
1.37 ! cvs 578: specifies the ways in which these basic elements are assembled into
! 579: structures representing complete documents and objects.</p>
1.1 cvs 580:
1.18 cvs 581: <div class="subsection">
1.37 ! cvs 582: <h3><a name="sectc311" id="sectc311">The basic types</a></h3>
1.1 cvs 583:
1.37 ! cvs 584: <p>At the lowest level of a document's structure, the first atom considered
! 585: is the character. However, since characters are seldom isolated, usually
1.1 cvs 586: appearing as part of a linear sequence, and in order to reduce the complexity
1.18 cvs 587: of the document structure, <em>character strings</em> are used as atoms and
1.37 ! cvs 588: consecutive characters belonging to the same structural element are grouped
! 589: in the same character string.</p>
1.30 cvs 590:
1.37 ! cvs 591: <p>If the structure of a document is not refined to go down to the level of
! 592: words or phrases, the contents of a simple paragraph can be considered to be
! 593: a single character string. On the other hand, the title of a chapter, the
! 594: title of the first section of that chapter, and the text of the first
! 595: paragraph of that section constitute three different character strings,
! 596: because they belong to distinct structural elements.</p>
1.30 cvs 597:
598: <p>If, instead, a very fine-grained representation for the structure of a
1.1 cvs 599: document is sought, character strings could be defined to contain only a
1.37 ! cvs 600: single word, or even just a single character. This is the case, for example,
! 601: in programs, for which one wants to retain a structure very close to the
! 602: syntax of the programming language. In this case, an assignment statement
1.1 cvs 603: initializing a simple variable to zero would be composed of two structural
604: elements, the identifier of the variable (a short character string) and the
1.18 cvs 605: assigned value (a string of a single character, `0').</p>
1.30 cvs 606:
607: <p>The character string is not the only atom necessary for representing those
1.37 ! cvs 608: documents that interest us. It suffices for purely textual documents, but as
1.1 cvs 609: soon as the non-textual objects which we have considered arise, there must be
610: other atoms; the number of objects which are to be represented determines the
1.18 cvs 611: number of types of atoms that are necessary.</p>
1.30 cvs 612:
613: <p>Primitive <em>graphical elements</em> are used for tables and figures of
1.37 ! cvs 614: different types. These elements are simple geometric shapes like horizontal
1.1 cvs 615: or vertical lines, which are sufficient for tables, or even oblique lines,
1.2 cvs 616: arrows, rectangles, circles, polygons, and curves for use in figures. From
617: these elements and character strings, graphical objects and tables can be
1.18 cvs 618: constructed.</p>
1.30 cvs 619:
620: <p>Photographs, though having very little structure, must still appear in
1.37 ! cvs 621: documents. They are supported by <em>picture</em> elements, which are
1.18 cvs 622: represented as matrices of pixels.</p>
1.30 cvs 623:
624: <p>Finally, mathematical notations require certain elements which are
1.37 ! cvs 625: simultaneously characters and graphical elements, the <em>symbols</em>. By
! 626: way of example, radicals, integration signs, or even large parentheses are
! 627: examples of this type of atom. The size of each of these symbols is
1.1 cvs 628: determined by its environment, that is to say, by the expression to which it
1.18 cvs 629: is attached.</p>
1.30 cvs 630:
631: <p>To summarize, the primitive elements which are used in the construction of
1.18 cvs 632: documents and structured objects are:</p>
633: <ul>
1.30 cvs 634: <li>character strings,</li>
635: <li>graphical elements,</li>
636: <li>pictures,</li>
637: <li>and mathematical symbols.</li>
1.18 cvs 638: </ul>
639: </div>
1.1 cvs 640:
1.18 cvs 641: <div class="subsection">
1.37 ! cvs 642: <h3><a name="sectc312" id="sectc312">Constructed elements</a></h3>
1.30 cvs 643:
1.37 ! cvs 644: <p>A document is evidently formed from primitive elements. But the model of
! 645: Thot also proposes higher level elements. Thus, in a document composed of
! 646: several chapters, each chapter is an element, and in the chapters each
! 647: section is also an element, and so on. A document is thus an organized set of
1.30 cvs 648: elements.</p>
1.1 cvs 649:
1.37 ! cvs 650: <p>In a document there are different sorts of elements. Each element has a
! 651: <em>type</em> which indicates the role of the element within the document as
! 652: a whole. Thus, we have, for example, the chapter and section types. The
1.1 cvs 653: document is made up of typed elements: elements of the type chapter and
1.37 ! cvs 654: elements of the type section, among others, but also character string
! 655: elements and graphical elements: the primitive elements are typed elements
! 656: just as well. At the other extreme, the document itself is also considered to
! 657: be a typed element.</p>
1.30 cvs 658:
659: <p>The important difference between the primitive elements and the other
1.37 ! cvs 660: elements of the document is that the primitive elements are atoms (they
! 661: cannot be decomposed), whereas the others, called <em>constructed
! 662: elements</em>, are composed of other elements, which can either be primitive
! 663: elements or constructed elements. A constructed element of type chapter (or
! 664: more simply, ``a chapter'') is composed of sections, which are also
! 665: constructed elements. A paragraph, a constructed element, can be made up of
! 666: character strings, which are primitive elements, and of equations, which are
! 667: constructed elements.</p>
1.30 cvs 668:
1.37 ! cvs 669: <p>A document is also a constructed element. This is an important point. In
1.1 cvs 670: particular, it allows a document to be treated as part of another document,
671: and conversely, permits a part of a document to be treated as a complete
1.37 ! cvs 672: document. Thus, an article presented in a journal is treated by its author as
1.1 cvs 673: a document in itself, while the editor of the journal considers it to be part
1.37 ! cvs 674: of an issue. A table or a figure appearing in a document can be extracted and
1.1 cvs 675: treated as a complete document, for example to prepare transparencies for a
1.18 cvs 676: conference.</p>
1.30 cvs 677:
678: <p>These thoughts about types and constructed elements apply just as well to
1.37 ! cvs 679: objects as they do to documents. A table is a constructed element made up of
! 680: other constructed elements, rows and columns. A row is formed of cells, which
1.1 cvs 681: are also constructed elements which contain primitive elements (character
1.18 cvs 682: strings) and/or constructed elements like equations.</p>
683: </div>
1.1 cvs 684:
1.18 cvs 685: <div class="subsection">
1.37 ! cvs 686: <h3><a name="sectc313" id="sectc313">Logical structure constructors</a></h3>
1.1 cvs 687:
1.30 cvs 688: <p>Having defined the primitive elements and the constructed elements, it is
689: now time to define the types of organization which allow the building of
1.37 ! cvs 690: structures. For this, we rely on the notion of the <em>constructor</em>. A
! 691: constructor defines a way of assembling certain elements in a structure. It
1.1 cvs 692: resides at the level of the meta-structure: it does not describe the existing
1.37 ! cvs 693: relations in a given structure, but rather defines how elements are assembled
1.18 cvs 694: to build a structure that conforms to a model.</p>
1.30 cvs 695:
696: <p>In defining the overall organization of documents, the first two
697: constructors considered are the aggregate and the list.</p>
1.1 cvs 698:
1.18 cvs 699: <div class="subsubsection">
1.37 ! cvs 700: <h4><a name="sectd3131" id="sectd3131">Aggregate and List</a></h4>
1.1 cvs 701:
1.30 cvs 702: <p>The <em>aggregate</em> constructor is used to define constructed element
703: types which are collections of a given number of other elements. These
1.37 ! cvs 704: collections may or may not be ordered. The elements may be either constructed
! 705: or primitive and are specified by their type. A report (that is, a
! 706: constructed element of the report type) has an aggregate structure. It is
1.30 cvs 707: formed from a title, an author's name, an introduction, a body, and a
1.37 ! cvs 708: conclusion, making it a collection of five element types. This type of
1.30 cvs 709: constructor is found in practically every document, and generally at several
710: levels in a document.</p>
711:
712: <p>The <em>list</em> constructor is used to define constructed elements which
713: are ordered sequences of elements (constructed or primitive) having the same
714: type. The minimum and maximum numbers of elements for the sequence can be
715: specified in the list constructor or the number of elements can be left
716: unconstrained. The body of a report is a list of chapters and is typically
717: required to contain a minimum of two chapters (is a chapter useful if it is
718: the only one in the report?) The chapter itself can contain a list of
1.37 ! cvs 719: sections, each section containing a list of paragraphs. In the same way as
! 720: the aggregate, the list is a very frequently used constructor in every type
! 721: of document. However, these two constructors are not sufficient to describe
! 722: every document structure; thus other constructors supplement them.</p>
1.18 cvs 723: </div>
1.1 cvs 724:
1.18 cvs 725: <div class="subsubsection">
1.37 ! cvs 726: <h4><a name="sectd3132" id="sectd3132">Choice, Schema, and Unit</a></h4>
1.1 cvs 727:
1.30 cvs 728: <p>The <em>choice</em> constructor is used to define the structure of an
729: element type for which one alternative is chosen from several possibilities.
1.37 ! cvs 730: Thus, a paragraph can be either a simple text paragraph, or an enumeration,
! 731: or a citation.</p>
1.30 cvs 732:
733: <p>The choice constructor indicates the complete list of possible options,
734: which can be too restrictive in certain cases, the paragraph being one such
735: case. Two constructors, <em>unit</em> and <em>schema</em>, address this
1.37 ! cvs 736: inconvenience. They allow more freedom in the choice of an element type. If a
! 737: paragraph is defined by a schema constructor, it is possible to put in the
1.1 cvs 738: place of a paragraph a table, an equation, a drawing or any other object
1.37 ! cvs 739: defined by another generic logical structure. It is also possible to define a
1.1 cvs 740: paragraph as a sequence of units, which could be character strings, symbols,
1.37 ! cvs 741: or pictures. The choice constructor alone defines a generic logical structure
1.1 cvs 742: that is relatively constrained; in contrast, using units and schemas, a very
1.18 cvs 743: open structure can be defined.</p>
1.30 cvs 744:
745: <p>The <em>schema</em> constructor represents an object defined by a generic
1.18 cvs 746: logical structure chosen freely from among those available.</p>
1.30 cvs 747:
748: <p>The <em>unit</em> constructor represents an element whose type can be
749: either a primitive type or an element type defined as a unit in the generic
750: logical structure of the document, or in another generic logical structure
1.37 ! cvs 751: used in the document. Such an element may be used in document objects
1.30 cvs 752: constructed according to other generic structures.</p>
753:
754: <p>Thus, for example, if a cross-reference to a footnote is defined in the
1.37 ! cvs 755: generic logical structure ``Article'' as a unit, a table (an object defined
! 756: by another generic structure) can contain cross-references to footnotes, when
! 757: they appear in an article. In another type of document, a table defined by
1.1 cvs 758: the same generic structure can contain other types of elements, depending on
1.37 ! cvs 759: the type of document into which the table is inserted. All that is needed is
1.1 cvs 760: to declare, in the generic structure for tables, that the contents of cells
1.37 ! cvs 761: are units. In this way, the generic structure of objects is divided up
! 762: between different types of documents which are able to adapt themselves to
! 763: the environment into which they are inserted.</p>
1.18 cvs 764: </div>
1.1 cvs 765:
1.18 cvs 766: <div class="subsubsection">
1.37 ! cvs 767: <h4><a name="sectd3133" id="sectd3133">Reference and Inclusion</a></h4>
1.1 cvs 768:
1.30 cvs 769: <p>The <em>reference</em> is used to define document elements that are
1.18 cvs 770: cross-references to other elements, such as a section, a chapter, a
1.37 ! cvs 771: bibliographic citation, or a figure. The reference is bi-directional. It can
1.18 cvs 772: be used to access both the element being cross-referenced and each of the
773: elements which make use of the cross-reference.</p>
1.30 cvs 774:
1.37 ! cvs 775: <p>References can be either <em>internal</em> or <em>external</em>. That is,
1.1 cvs 776: they can designate elements which appear in the same document or in another
1.18 cvs 777: document.</p>
1.30 cvs 778:
1.37 ! cvs 779: <p>The <em><a name="inclusion" id="inclusion">inclusion</a></em> constructor
! 780: is a special type of reference. Like the reference, it is an internal or
! 781: external bidirectional link, but it is not a cross-reference. This link
! 782: represents the ``live'' inclusion of the designated element; it accesses the
! 783: most recent version of that element and not a ``dead'' copy, fixed in the
! 784: state in which it was found at the moment the copy was made. As soon as an
! 785: element is modified, all of its inclusions are automatically brought up to
! 786: date. It must be noted that, in addition to inclusion, Thot permits the
! 787: creation of ``dead'' copies.</p>
1.30 cvs 788:
789: <p>There are three types of inclusions: inclusions with full expansion,
1.1 cvs 790: inclusions with partial expansion, and inclusions without expansion. During
791: editing, inclusions without expansion are represented on the screen by the
792: name of the included document, in a special color, while inclusions with
1.37 ! cvs 793: expansion (full or partial) are represented by a copy (full or partial) of
! 794: the included element (also in a special color). The on-screen representation
! 795: of a partial inclusion is a <a href="#sectc3213">``skeleton''</a> image of
! 796: the included document.</p>
1.30 cvs 797:
798: <p>Inclusion with complete expansion can be used to include parts of the same
1.37 ! cvs 799: document or of other documents. Thus, it can be either an internal or an
! 800: external link. It can be used to include certain bibliographic entries of a
1.1 cvs 801: scientific article in another article, or to copy part of a mathematical
802: formula into another formula of the same document, thus assuring that both
1.18 cvs 803: copies will remain synchronized.</p>
1.30 cvs 804:
805: <p>Inclusion without expansion or with partial expansion is used to include
1.37 ! cvs 806: complete documents. It is always an external link. It is used primarily to
1.1 cvs 807: divide very large documents into sub-documents that are easier to manipulate,
1.37 ! cvs 808: especially when there are many authors. So, a book can include some chapters,
1.1 cvs 809: where each chapter is a different document which can be edited separately.
810: When viewing the book on the screen, it might be desirable to see only the
1.37 ! cvs 811: titles of the chapters and sections. This can be achieved using inclusion
1.18 cvs 812: with partial expansion.</p>
1.30 cvs 813:
1.37 ! cvs 814: <p>During printing, inclusions without expansion or with partial expansion
! 815: can be represented either as they were shown on the screen or by a complete
! 816: (and up-to-date) copy of the included element or document.</p>
1.30 cvs 817:
818: <p>The inclusion constructor, whatever its type, respects the generic
819: structure: only those elements authorized by the generic structure can be
820: included at a given position in a document.</p>
1.18 cvs 821: </div>
1.1 cvs 822:
1.18 cvs 823: <div class="subsubsection">
1.37 ! cvs 824: <h4><a name="sectd3134" id="sectd3134">Mark pairs</a></h4>
1.1 cvs 825:
1.30 cvs 826: <p>It is often useful to delimit certain parts of a document independently
1.37 ! cvs 827: from the logical structure. For example, one might wish to attach some
1.30 cvs 828: information (in the form of an <a href="#sectc315">attribute</a>) or a
829: particular treatment to a group of words or a set of consecutive paragraphs.
830: <em>Mark pairs</em> are used to do this.</p>
831:
832: <p>Mark pairs are elements which are always paired and are terminals in the
1.37 ! cvs 833: logical structure of the document. Their position in the structure of the
! 834: document is defined in the generic structure. It is important to note that
1.18 cvs 835: when the terminals of a mark pair are <em>extensions</em> (see the next
836: section), they can be used quite freely.</p>
837: </div>
1.1 cvs 838:
1.18 cvs 839: <div class="subsubsection">
1.37 ! cvs 840: <h4><a name="sectd3135" id="sectd3135">Restrictions and Extensions</a></h4>
1.1 cvs 841:
1.30 cvs 842: <p>The primitive types and the constructors presented so far permit the
1.1 cvs 843: definition of the logical structure of documents and objects in a rigorous
1.37 ! cvs 844: way. But this definition can be very cumbersome in certain cases, notably
1.1 cvs 845: when trying to constrain or extend the authorized element types in a
1.37 ! cvs 846: particular context. <em>Restrictions</em> and <em>extensions</em> are used to
1.18 cvs 847: cope with these cases.</p>
1.30 cvs 848:
849: <p>A restriction associates with a particular element type <em>A</em>, a list
1.37 ! cvs 850: of those element types which elements of type <em>A</em> may not contain,
! 851: even if the definition of type <em>A</em> and those of its components
! 852: authorize them otherwise. This simplifies the writing of generic logical
! 853: structures and allows limitations to be placed, when necessary, on the
! 854: choices offered by the schema and unit constructors.</p>
! 855:
! 856: <p>Extensions are the inverse of restrictions. They identify a list of
! 857: element types whose presence <em>is</em> permitted, even if its definition
! 858: and those of its components do not authorize them otherwise.</p>
1.18 cvs 859: </div>
860:
861: <div class="subsubsection">
1.37 ! cvs 862: <h4><a name="sectd3136" id="sectd3136">Summary</a></h4>
1.18 cvs 863:
1.30 cvs 864: <p>Thus, four constructors are used to construct a document:</p>
1.18 cvs 865: <ul>
1.30 cvs 866: <li>the aggregate constructor (ordered or not),</li>
867: <li>the list constructor,</li>
868: <li>the choice constructor and its extensions, the unit and schema
869: constructors,</li>
870: <li>the reference constructor and its variant, the inclusion.</li>
871: </ul>
872:
1.37 ! cvs 873: <p>These constructors are also sufficient for objects. Thus, these
1.30 cvs 874: constructors provide a homogenous meta-model which can describe both the
875: organization of the document as a whole and that of the various types of
1.37 ! cvs 876: objects which it contains. After presenting the description language for
1.30 cvs 877: generic structures, we will present several examples which illustrate the
878: appropriateness of the model.</p>
879:
1.37 ! cvs 880: <p>The first three constructors (aggregate, list and choice) lead to
! 881: tree-like structures for documents and objects, the objects being simply the
! 882: subtrees of the tree of a document (or even of other objects' subtrees). The
! 883: reference constructor introduces other, non-hierarchical, relations which
! 884: augment those of the tree: when a paragraph makes reference to a chapter or a
! 885: section, that relation leaves the purely tree-like structure. Moreover,
! 886: external reference and inclusion constructors permit the establishment of
! 887: links between different documents, thus creating a hypertext structure.</p>
1.18 cvs 888: </div>
889: </div>
1.1 cvs 890:
1.18 cvs 891: <div class="subsection">
1.37 ! cvs 892: <h3><a name="sectc315" id="sectc315">Attributes</a></h3>
1.1 cvs 893:
1.30 cvs 894: <p>There remain logical aspects of documents that are not entirely described
1.37 ! cvs 895: by the structure. Certain types of semantic information, which are not stated
! 896: explicitly in the text, must also be taken into account. In particular, such
1.1 cvs 897: information is shown by typographic effects which do not correspond to a
1.37 ! cvs 898: change between structural elements. In fact, certain titles are set in bold
1.1 cvs 899: or italic or are printed in a different typeface from the rest of the text in
1.37 ! cvs 900: order to mark them as structurally distinct. But these same effects
1.1 cvs 901: frequently appear in the middle of continuous text (e.g. in the interior of a
1.37 ! cvs 902: paragraph). In this case, there is no change between structural elements; the
! 903: effect serves to highlight a word, expression, or phrase. The notion of an
1.18 cvs 904: <em>attribute</em> is used to express this type of information.</p>
1.30 cvs 905:
906: <p>An attribute is a piece of information attached to a structural element
907: which augments the type of the element and clarifies its function in the
908: document. Keywords, foreign language words, and titles of other works can all
1.37 ! cvs 909: be represented by character strings with attached attributes. Attributes may
! 910: also be attached to constructed elements. Thus, an attribute indicating the
1.1 cvs 911: language can be attached to a single word or to a large part of a
1.18 cvs 912: document.</p>
1.30 cvs 913:
914: <p>In fact, an attribute can be any piece of information which is linked to a
1.37 ! cvs 915: part of a document and which can be used by agents which work on the
! 916: document. For example, the language in which the document is written
! 917: determines the set of characters used by an editor or formatter. It also
! 918: determines the algorithm or hyphenation dictionary to be used. The attribute
! 919: ``keyword'' facilitates the work of an information retrieval system. The
! 920: attribute ``index word'' allows a formatter to automatically construct an
! 921: index at the end of the document.</p>
1.30 cvs 922:
923: <p>As with the types of constructed elements, the attributes and the values
1.37 ! cvs 924: they can take are defined separately in each generic logical structure, not
! 925: in the meta-model, according to the needs of the document class or the nature
! 926: of the object.</p>
1.30 cvs 927:
928: <p>Many types of attributes are offered: numeric, textual, references, and
1.18 cvs 929: enumerations:</p>
930: <ul>
1.37 ! cvs 931: <li><em>Numeric attributes</em> can take integer values (negative,
! 932: positive, or null).</li>
1.30 cvs 933: <li><em>Textual attributes</em> have as their values character strings.</li>
934: <li><em>Reference attributes</em> designate an element of the logical
935: structure.</li>
936: <li><em>Enumeration attributes</em> can take one value from a limited list
937: of possible values, each value being a name.</li>
1.18 cvs 938: </ul>
1.30 cvs 939:
940: <p>In a generic structure, there is a distinction between <em>global
1.37 ! cvs 941: attributes</em> and <em>local attributes</em>. A global attribute can be
1.1 cvs 942: applied to every element type defined in the generic structure where it is
1.37 ! cvs 943: specified. In contrast, a local attribute can only be applied to certain
! 944: types of elements, even only a single type. The ``language'' attribute
! 945: presented above is an example of a global attribute. An example of a local
1.1 cvs 946: attribute is the rank of an author (principal author of the document or
947: secondary author): this attribute can only be applied sensibly to an element
1.18 cvs 948: of the ``author'' type.</p>
1.30 cvs 949:
950: <p>Attributes can be assigned to the elements which make up the document in
1.37 ! cvs 951: many different ways. The author can freely and dynamically place them on any
1.30 cvs 952: part of the document in order to attach supplementary information of his/her
1.18 cvs 953: choice. However, attributes may only be assigned in accordance with the rules
1.37 ! cvs 954: of the generic structure; in particular, local attributes can only be
! 955: assigned to those element types for which they are defined.</p>
1.30 cvs 956:
957: <p>In the generic structure, certain local attributes can be made mandatory
1.37 ! cvs 958: for certain element types. In this case, Thot automatically associates the
! 959: attribute with the elements of this type and it requires the user to provide
! 960: a value for this attribute.</p>
! 961:
! 962: <p>Attributes can also be automatically assigned, with a given value, by
! 963: every application processing the document in order to systematically add a
! 964: piece of information to certain predefined elements of the document. By way
! 965: of example, in a report containing a French abstract and an English abstract,
! 966: each of the two abstracts is defined as a sequence of paragraphs. The first
1.1 cvs 967: abstract has a value of ``French'' for the ``language'' attribute while the
1.18 cvs 968: second abstract's ``language'' attribute has a value of ``English''.</p>
1.30 cvs 969:
970: <p>In the case of mark pairs, attributes are logically associated with the
971: pair as a whole, but are actually attached to the first mark.</p>
1.18 cvs 972: </div>
1.1 cvs 973:
1.18 cvs 974: <div class="subsection">
1.37 ! cvs 975: <h3><a name="sectc316" id="sectc316">Discussion of the model</a></h3>
1.1 cvs 976:
1.37 ! cvs 977: <p>The notions of attribute, constructor, and structured element are used in
! 978: the definition of generic logical structures of documents and objects. The
! 979: problem is to assemble them to form generic structures. In fact, many types
! 980: of elements and attributes can be found in a variety of generic structures.
! 981: Rather than redefine them for each structure in which they appear, it is best
! 982: to share them between structures. The object classes already fill this
! 983: sharing function. If a mathematical class is defined, its formulas can be
! 984: used in many different document classes, without redefining the structure of
! 985: each class. This problem arises not only for the objects considered here; it
! 986: also arises for the commonplace textual elements found in many document
! 987: classes. This is the reason why the notion of object is so broad and why
! 988: paragraphs and enumerations are also considered to be objects. These object
! 989: classes not only permit the sharing of the structures of elements, but also
! 990: of the attributes defined in the generic structures.</p>
1.30 cvs 991:
992: <p>Structure, such as that presented here, can appear very rigid, and it is
1.1 cvs 993: possible to imagine that a document editing system based on this model could
1.37 ! cvs 994: prove very constraining to the user. This is, in fact, a common criticism of
! 995: syntax-directed editors. This defect can be avoided with Thot, primarily for
1.18 cvs 996: three reasons:</p>
997: <ul>
1.30 cvs 998: <li>the generic structures are not fixed in the model itself,</li>
999: <li>the model takes the dynamics of documents into account,</li>
1000: <li>the constructors offer great flexibility.</li>
1.18 cvs 1001: </ul>
1.30 cvs 1002:
1003: <p>When the generic structure of a document is not predefined, but rather is
1.1 cvs 1004: constructed specifically for each document class, it can be carefully adapted
1.37 ! cvs 1005: to the current needs. In cases where the generic structure is inadequate for
1.1 cvs 1006: a particular document of the class, it is always possible either to create a
1007: new class with a generic structure well suited to the new case or to extend
1.37 ! cvs 1008: the generic structure of the existing class to take into account the
! 1009: specifics of the document which poses the problem. These two solutions can
! 1010: also be applied to objects whose structures prove to be poorly designed.</p>
1.30 cvs 1011:
1012: <p>The model is sufficiently flexible to take into account all the phases of
1.37 ! cvs 1013: the life of the document. When a generic structure specifies that a report
! 1014: must contain a title, an abstract, an introduction, at least two chapters,
! 1015: and a conclusion, this means only that a report, <em>upon completion</em>,
! 1016: will have to contain all of these elements. When the author begins writing,
! 1017: none of these elements is present. Thot uses this model. Therefore, it
! 1018: tolerates documents which do not conform strictly to the generic structure of
! 1019: their class; it also considers the generic logical structure to be a way of
! 1020: helping the user in the construction of a complex document.</p>
1.30 cvs 1021:
1022: <p>In contrast, other applications may reject a document which does not
1.37 ! cvs 1023: conform strictly to its generic structure. This is, for example, what is done
1.30 cvs 1024: by compilers which refuse to generate code for a program which is not
1.37 ! cvs 1025: syntactically correct. This might also occur when using a document
1.18 cvs 1026: application for a report which does not have an abstract or title.</p>
1.30 cvs 1027:
1028: <p>The constructors of the document model bring a great flexibility to the
1.37 ! cvs 1029: generic structures. A choice constructor (and even more, a unit or schema
! 1030: constructor) can represent several, very different elements. The list
! 1031: constructor permits the addition of more elements of the same type. Used
1.1 cvs 1032: together, these two constructors permit any series of elements of different
1.37 ! cvs 1033: types. Of course, this flexibility can be reduced wherever necessary since a
1.1 cvs 1034: generic structure can limit the choices or the number of elements in a
1.18 cvs 1035: list.</p>
1.30 cvs 1036:
1037: <p>Another difficulty linked to the use of structure in the document model
1.37 ! cvs 1038: resides in the choice of the level of the structure. The structure of a
1.1 cvs 1039: discussion could be extracted from the text itself via linguistic analysis.
1040: Some studies are exploring this approach, but the model of Thot excludes this
1.37 ! cvs 1041: type of structure. It only takes into account the logical structure provided
1.18 cvs 1042: explicitly by the author.</p>
1.30 cvs 1043:
1.37 ! cvs 1044: <p>However, the level of structure of the model is not imposed. Each generic
! 1045: structure defines its own level of structure, adapted to the document class
! 1046: or object and to the ways in which it will be processed. If it will only be
! 1047: edited and printed, a relatively simple structure suffices. If more
! 1048: specialized processing will be applied to it, the structure must represent
! 1049: the element types on which this processing must act. By way of example, a
! 1050: simple structure is sufficient for printing formulas, but a more complex
! 1051: structure is required to perform symbolic or numeric calculations on the
! 1052: mathematical expressions. The document model of Thot allows both types of
! 1053: structure.</p>
1.18 cvs 1054: </div>
1055: </div>
1.1 cvs 1056:
1.18 cvs 1057: <div class="section">
1.37 ! cvs 1058: <h2><a name="sectb32" id="sectb32">The definition language for generic
! 1059: structures</a></h2>
1.1 cvs 1060:
1.37 ! cvs 1061: <p>Generic structures, which form the basis of the document model of Thot,
! 1062: are specified using a special language. This definition language, called S,
! 1063: is described in this section.</p>
1.30 cvs 1064:
1065: <p>Each generic structure, which defines a class of documents or objects, is
1.2 cvs 1066: specified by a file, written in the S language, which is called a
1.37 ! cvs 1067: <em>structure schema</em>. Structure schemas are compiled into tables, called
1.18 cvs 1068: structure tables, which are used by Thot and which determine its behavior.</p>
1.1 cvs 1069:
1.18 cvs 1070: <div class="subsection">
1.37 ! cvs 1071: <h3><a name="sectc321" id="sectc321">Writing Conventions</a></h3>
1.1 cvs 1072:
1.30 cvs 1073: <p>The grammar of S, like those of the languages P and T presented later, is
1.1 cvs 1074: described using the meta-language M, derived from the Backus-Naur Form
1.18 cvs 1075: (BNF).</p>
1.30 cvs 1076:
1077: <p>In this meta-language each rule of the grammar is composed of a grammar
1.37 ! cvs 1078: symbol followed by an equals sign (`=') and the right part of the rule. The
1.30 cvs 1079: equals sign plays the same role as the traditional `::=' of BNF: it indicates
1.37 ! cvs 1080: that the right part defines the symbol of the left part. In the right
1.30 cvs 1081: part,</p>
1.18 cvs 1082: <dl>
1.30 cvs 1083: <dt>concatenation</dt>
1084: <dd>is shown by the juxtaposition of symbols;</dd>
1085: <dt>character strings</dt>
1.37 ! cvs 1086: <dd>between apostrophes ' represent terminal symbols, that is, keywords
! 1087: in the language defined. Keywords are written here in upper-case
! 1088: letters, but can be written in any combination of upper and lower-case
! 1089: letters. For example, the keyword <tt>DEFPRES</tt> of S can also be
! 1090: written as <tt>defpres</tt> or <tt>DefPres</tt>.</dd>
1.30 cvs 1091: <dt>material between brackets</dt>
1092: <dd>(`[' and `]') is optional;</dd>
1093: <dt>material between angle brackets</dt>
1094: <dd>(`<' and `>') can be repeated many times or omitted;</dd>
1095: <dt>the slash</dt>
1.37 ! cvs 1096: <dd>(`/') indicates an alternative, a choice between the options
! 1097: separated by the slash character;</dd>
1.30 cvs 1098: <dt>the period</dt>
1099: <dd>marks the end of a rule;</dd>
1100: <dt>text between braces</dt>
1101: <dd>(`{' and `}') is simply a comment.</dd>
1.18 cvs 1102: </dl>
1.30 cvs 1103:
1104: <p>The M meta-language also uses the concepts of identifiers, strings, and
1.18 cvs 1105: integers:</p>
1106: <dl>
1.30 cvs 1107: <dt><tt>NAME</tt></dt>
1.37 ! cvs 1108: <dd>represents an identifier, a sequence of letters (upper or
! 1109: lower-case), digits, and underline characters (`_'), beginning with a
! 1110: letter. Also considered a letter is the sequence of characters
! 1111: `<tt>\nnn</tt>' where the letter <tt>n</tt> represents the ISO Latin-1
! 1112: code of the letter in octal. It is thus possible to use accented
! 1113: letters in identifiers. The maximum length of identifiers is fixed by
! 1114: the compiler. It is normally 31 characters.
1.30 cvs 1115: <p>Unlike keywords, upper and lower-case letters are distinct in
1116: identifiers. Thus, <tt>Title</tt>, <tt>TITLE</tt>, and <tt>title</tt>
1117: are considered different identifiers.</p>
1118: </dd>
1119: <dt><tt>STRING</tt></dt>
1.37 ! cvs 1120: <dd>represents a string. This is a string of characters delimited by
! 1121: apostrophes. If an apostrophe must appear in a string, it is doubled.
! 1122: As with identifiers, strings can contain characters represented by
! 1123: their octal code (after a backslash). As with apostrophes, if a
! 1124: backslash must appear in a string, it is doubled.</dd>
1.30 cvs 1125: <dt><tt>NUMBER</tt></dt>
1126: <dd>represents a positive integer or zero (without a sign), or said
1127: another way, a sequence of decimal digits.</dd>
1.18 cvs 1128: </dl>
1.30 cvs 1129:
1130: <p>The M language can be used to define itself as follows:</p>
1.18 cvs 1131: <pre>{ Any text between braces is a comment. }
1.30 cvs 1132: Grammar = Rule < Rule > 'END' .
1133: { The < and > signs indicate zero }
1.1 cvs 1134: { or more repetitions. }
1135: { END marks the end of the grammar. }
1136: Rule = Ident '=' RightPart '.' .
1137: { The period indicates the end of a rule }
1138: RightPart = RtTerminal / RtIntermed .
1139: { The slash indicates a choice }
1140: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
1141: { Right part of a terminal rule }
1.30 cvs 1142: RtIntermed = Possibility < '/' Possibility > .
1.1 cvs 1143: { Right part of an intermediate rule }
1.30 cvs 1144: Possibility = ElemOpt < ElemOpt > .
1145: ElemOpt = Element / '[' Element < Element > ']' /
1146: '<' Element < Element > '>' .
1.1 cvs 1147: { Brackets delimit optional parts }
1148: Element = Ident / KeyWord .
1149: Ident = NAME .
1150: { Identifier, sequence of characters }
1151: KeyWord = STRING .
1152: { Character string delimited by apostrophes }
1.18 cvs 1153: END</pre>
1154: </div>
1.1 cvs 1155:
1.18 cvs 1156: <div class="subsection">
1.37 ! cvs 1157: <h3><a name="sectc322" id="sectc322">Extension schemas</a></h3>
1.1 cvs 1158:
1.30 cvs 1159: <p>A structure schema defines the generic logical structure of a class of
1.1 cvs 1160: documents or objects, independent of the operations which can be performed on
1.37 ! cvs 1161: the documents. However, certain applications may require particular
1.1 cvs 1162: information to be represented by the structure for the documents that they
1.37 ! cvs 1163: operate on. Thus a document version manager will need to indicate in the
! 1164: document the parts which belong to one version or another. An indexing system
1.1 cvs 1165: will add highly-structured index tables as well as the links between these
1.18 cvs 1166: tables and the rest of the document.</p>
1.30 cvs 1167:
1168: <p>Thus, many applications need to extend the generic structure of the
1.37 ! cvs 1169: documents on which they operate to introduce new attributes or element types.
! 1170: These additions are specific to each application and must be able to be
! 1171: applied to any generic structure: users will want to manage versions or
! 1172: construct indices for many types of documents. Extension schemas fulfill this
! 1173: role: they define attributes, elements, units, etc., but they can only be
! 1174: used jointly with a structure schema that they complete. Otherwise, structure
! 1175: schemas can always be used without these extensions when the corresponding
! 1176: applications are not available.</p>
1.18 cvs 1177: </div>
1.1 cvs 1178:
1.18 cvs 1179: <div class="subsection">
1.37 ! cvs 1180: <h3><a name="sectc323" id="sectc323">The general organization of structure
! 1181: schemas</a></h3>
1.1 cvs 1182:
1.30 cvs 1183: <p>Every structure schema begins with the keyword <tt>STRUCTURE</tt> and ends
1.37 ! cvs 1184: with the keyword <tt>END</tt>. The keyword <tt>STRUCTURE</tt> is followed by
1.18 cvs 1185: the keyword <tt>EXTENSION</tt> in the case where the schema defines an
1.1 cvs 1186: extension, then by the name of the generic structure which the schema defines
1.37 ! cvs 1187: (the name of the document or object class). The name of the structure is
1.18 cvs 1188: followed by a semicolon.</p>
1.30 cvs 1189:
1190: <p>In the case of a complete schema (that is, a schema which is not an
1.1 cvs 1191: extension), the definition of the name of the structure is followed by the
1192: declarations of the default presentation schema, the global attributes, the
1.37 ! cvs 1193: structure rules, the units, the skeleton elements and the exceptions. Only
! 1194: the definition of the structure rules is required. Each series of
! 1195: declarations begins with a keyword: <tt>DEFPRES</tt>, <tt>ATTR</tt>,
! 1196: <tt>STRUCT</tt>, <tt>UNITS</tt>, <tt>EXPORT</tt>, <tt>EXCEPT</tt>.</p>
1.34 cvs 1197:
1198: <p>In the case of an extension schema, there are no skeleton elements and the
1199: <tt>STRUCT</tt> section is optional, while that section is required in a
1.37 ! cvs 1200: schema that is not an extension. On the other hand, extension schemas can
! 1201: contain an <tt>EXTENS</tt> section, which must not appear in a schema which
! 1202: is not an extension; this section defines the complements to attach to the
! 1203: rules found in the schema to which the extension will be added. The sections
! 1204: <tt>ATTR</tt>, <tt>STRUCT</tt>, and <tt>UNITS</tt> define new attributes, new
! 1205: elements, and new units which add their definitions to the principal
! 1206: schema.</p>
1.18 cvs 1207: <pre> StructSchema ='STRUCTURE' ElemID ';'
1.1 cvs 1208: 'DEFPRES' PresID ';'
1209: [ 'ATTR' AttrSeq ]
1210: 'STRUCT' RulesSeq
1211: [ 'UNITS' RulesSeq ]
1212: [ 'EXPORT' SkeletonSeq ]
1213: [ 'EXCEPT' ExceptSeq ]
1214: 'END' .
1.18 cvs 1215: ElemID = NAME .</pre>
1.30 cvs 1216:
1217: <p>or</p>
1.18 cvs 1218: <pre> ExtensSchema ='STRUCTURE' 'EXTENSION' ElemID ';'
1.1 cvs 1219: 'DEFPRES' PresID ';'
1220: [ 'ATTR' AttrSeq ]
1221: [ 'STRUCT' RulesSeq ]
1222: [ 'EXTENS' ExtensRuleSeq ]
1223: [ 'UNITS' RulesSeq ]
1224: [ 'EXCEPT' ExceptSeq ]
1225: 'END' .
1.18 cvs 1226: ElemID = NAME .</pre>
1227: </div>
1.1 cvs 1228:
1.18 cvs 1229: <div class="subsection">
1.37 ! cvs 1230: <h3><a name="sectc324" id="sectc324">The default presentation</a></h3>
1.1 cvs 1231:
1.37 ! cvs 1232: <p>It was shown <a href="#mulpres">above</a> that many different
! 1233: presentations are possible for documents and objects of the same class. The
! 1234: structure schema defines a preferred presentation for the class, called the
! 1235: <em>default presentation</em>. Like generic structures, presentations are
! 1236: described by programs, called <em>presentation schemas</em>, which are
! 1237: written in a specific language, P, presented <a href="#sectb42">later</a> in
! 1238: this document. The name appearing after the keyword <tt>DEFPRES</tt> is the
! 1239: name of the default presentation schema. When a new document is created, Thot
! 1240: will use this presentation schema by default, but the user remains free to
! 1241: choose another if s/he wishes.</p>
1.18 cvs 1242: <pre> PresID = NAME .</pre>
1243: </div>
1.1 cvs 1244:
1.18 cvs 1245: <div class="subsection">
1.37 ! cvs 1246: <h3><a name="sectc325" id="sectc325">Global Attributes</a></h3>
1.1 cvs 1247:
1.30 cvs 1248: <p>If the generic structure includes global attributes of its own, they are
1.37 ! cvs 1249: declared after the keyword <tt>ATTR</tt>. Each global attribute is defined by
! 1250: its name, followed by an equals sign and the definition of its type. The
1.18 cvs 1251: declaration of a global attribute is terminated by a semi-colon.</p>
1.30 cvs 1252:
1253: <p>For attributes of the numeric, textual, or reference types, the type is
1.37 ! cvs 1254: indicated by a keyword, <tt>INTEGER</tt>, <tt>TEXT</tt>, or
! 1255: <tt>REFERENCE</tt> respectively.</p>
1.30 cvs 1256:
1257: <p>In the case of a reference attribute, the keyword <tt>REFERENCE</tt> is
1.37 ! cvs 1258: followed by the type of the referenced element in parentheses. It can refer
1.18 cvs 1259: to any type at all, specified by using the keyword <tt>ANY</tt>, or to a
1.37 ! cvs 1260: specific type. In the latter case, the element type designated by the
1.18 cvs 1261: reference can be defined either in the <a href="#sectc327"><tt>STRUCT</tt>
1262: section</a> of the same structure schema or in the <tt>STRUCT</tt> section of
1.37 ! cvs 1263: another structure schema. When the type is defined in another schema, the
1.1 cvs 1264: element type is followed by the name of the structure schema (within
1.37 ! cvs 1265: parentheses) in which it is defined. The name of the designated element type
1.18 cvs 1266: can be preceded by the keyword <tt>First</tt> or <tt>Second</tt>, but only in
1.37 ! cvs 1267: the case where the type is defined as <a href="#sectd3285">a pair</a>. These
1.1 cvs 1268: keywords indicate whether the attribute must designate the first mark of the
1.37 ! cvs 1269: pair or the second. If the reference refers to a pair and neither of these
1.18 cvs 1270: two keywords is present, then the first mark is used.</p>
1.30 cvs 1271:
1.37 ! cvs 1272: <p>In the case of an enumeration attribute, the equals sign is followed by
! 1273: the list of names representing the possible values of the attribute, the
! 1274: names being separated from each other by commas. An enumeration attribute has
! 1275: at least one possible value; the maximum number of values is defined by the
1.18 cvs 1276: compiler for the S language.</p>
1.30 cvs 1277: <pre> AttrSeq = Attribute < Attribute > .
1.1 cvs 1278: Attribute = AttrID '=' AttrType ';' .
1279: AttrType = 'INTEGER' / 'TEXT' /
1280: 'REFERENCE' '(' RefType ')' /
1281: ValueSeq .
1282: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .
1283: FirstSec = 'First' / 'Second' .
1284: ExtStruct = '(' ElemID ')' .
1.30 cvs 1285: ValueSeq = AttrVal < ',' AttrVal > .
1.1 cvs 1286: AttrID = NAME .
1.18 cvs 1287: AttrVal = NAME .</pre>
1.30 cvs 1288:
1289: <p>There is a predefined global text attribute, the <em>language</em>, which
1.37 ! cvs 1290: is automatically added to every Thot structure schema. This attribute allows
! 1291: Thot to perform certain actions, such as hyphenation and spell-checking,
! 1292: which cannot be performed without knowing the language in which each part of
! 1293: the document is written. This attribute can be used just like any explicitly
1.18 cvs 1294: declared attribute: the system acts as if every structure schema contains</p>
1295: <pre>ATTR
1296: Language = TEXT;</pre>
1.30 cvs 1297:
1.18 cvs 1298: <blockquote class="example">
1.30 cvs 1299: <p><strong>Example:</strong></p>
1300:
1301: <p>The following specification defines the global enumeration attribute
1302: WordType.</p>
1303: <pre>ATTR
1.18 cvs 1304: WordType = Definition, IndexWord, DocumentTitle;</pre>
1305: </blockquote>
1306: </div>
1.1 cvs 1307:
1.18 cvs 1308: <div class="subsection">
1.37 ! cvs 1309: <h3><a name="sectc327" id="sectc327">Structured elements</a></h3>
1.1 cvs 1310:
1.30 cvs 1311: <p>The rules for defining structured elements are required, except in an
1.1 cvs 1312: extension schema: they constitute the core of a structure schema, since they
1313: define the structure of the different types of elements that occur in a
1.18 cvs 1314: document or object of the class defined by the schema.</p>
1.30 cvs 1315:
1316: <p>The first structure rule after the keyword <tt>STRUCT</tt> must define the
1.1 cvs 1317: structure of the class whose name appears in the first instruction
1.37 ! cvs 1318: (<tt>STRUCTURE</tt>) of the schema. This is the root rule of the schema,
1.18 cvs 1319: defining the root of the document tree or object tree.</p>
1.30 cvs 1320:
1321: <p>The remaining rules may be placed in any order, since the language permits
1.37 ! cvs 1322: the definition of element types before or after their use, or even in the
! 1323: same instruction in which they are used. This last case allows the definition
! 1324: of recursive structures.</p>
1.30 cvs 1325:
1326: <p>Each rule is composed of a name (the name of the element type whose
1327: structure is being defined) followed by an equals sign and a structure
1328: definition.</p>
1329:
1.37 ! cvs 1330: <p>If any local attributes are associated with the element type defined by
! 1331: the rule, they appear between parentheses after the type name and before the
! 1332: equals sign. The parentheses contain, first, the keyword <tt>ATTR</tt>, then
! 1333: the list of local attributes, separated by commas. Each local attribute is
1.2 cvs 1334: composed of the name of the attribute followed by an equals sign and the
1.18 cvs 1335: definition of the attribute's type, just as in the definition of <a
1.37 ! cvs 1336: href="#sectc325">global attributes</a>. The name of the attribute can be
! 1337: preceded by an exclamation point to indicate that the attribute must always
! 1338: be present for this element type. The same attribute, identified by its name,
! 1339: can be defined as a local attribute for multiple element types. In this case,
! 1340: the equals sign and definition of the attribute type need only appear in the
! 1341: first occurrence of the attribute. It should be noted that global attributes
! 1342: cannot also be defined as local attributes.</p>
1.30 cvs 1343:
1344: <p>If any <a href="#sectd3135">extensions</a> are defined for this element
1345: type, a plus sign follows the structure definition and the names of the
1.37 ! cvs 1346: extension element types appear between parentheses after the plus. If there
! 1347: are multiple extensions, they are separated by commas. These types can either
1.30 cvs 1348: be defined in the same schema, defined in other schemas, or they may be base
1.18 cvs 1349: types identified by the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>,
1350: <tt>SYMBOL</tt>, or <tt>PICTURE</tt>.</p>
1.30 cvs 1351:
1352: <p><a href="#sectd3135">Restrictions</a> are indicated in the same manner as
1.18 cvs 1353: extensions, but they are introduced by a minus sign and they come after the
1354: extensions, or if there are no extensions, after the structure definition.</p>
1.30 cvs 1355:
1.37 ! cvs 1356: <p>If the values of attributes must be attached systematically to this
! 1357: element type, they are introduced by the keyword <tt>WITH</tt> and declared
! 1358: in the form of a list of fixed-value attributes. When such definitions of
! 1359: fixed attribute values appear, they are always the last part of the rule.</p>
1.30 cvs 1360:
1361: <p>The rule is terminated by a semicolon.</p>
1362: <pre> RuleSeq = Rule < Rule > .
1.1 cvs 1363: Rule = ElemID [ LocAttrSeq ] '=' DefWithAttr ';'.
1.30 cvs 1364: LocAttrSeq = '(' 'ATTR' LocAttr < ';' LocAttr > ')' .
1.1 cvs 1365: LocAttr = [ '!' ] AttrID [ '=' AttrType ] .
1366: DefWithAttr = Definition
1367: [ '+' '(' ExtensionSeq ')' ]
1368: [ '-' '(' RestrictSeq ')' ]
1369: [ 'WITH' FixedAttrSeq ] .
1.30 cvs 1370: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1.1 cvs 1371: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
1372: 'SYMBOL' / 'PICTURE' .
1.30 cvs 1373: RestrictSeq = RestrictElem < ',' RestrictElem > .
1.1 cvs 1374: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
1.18 cvs 1375: 'SYMBOL' / 'PICTURE' .</pre>
1.30 cvs 1376:
1377: <p>The list of fixed-value attributes is composed of a sequence of
1.37 ! cvs 1378: attribute-value pairs separated by commas. Each pair contains the name of the
1.1 cvs 1379: attribute and the fixed value for this element type, the two being separated
1.37 ! cvs 1380: by an equals sign. If the sign is preceded by a question mark the given value
1.1 cvs 1381: is only an initial value that may be modified later rather than a value fixed
1.37 ! cvs 1382: for all time. Reference attributes are an exception to this norm. They cannot
! 1383: be assigned a fixed value, but when the name of such an attribute appears
! 1384: this indicates that this element type must have a valid value for the
! 1385: attribute. For the other attribute types, the fixed value is indicated by a
1.1 cvs 1386: signed integer (numeric attributes), a character string between apostrophes
1.18 cvs 1387: (textual attributes) or the name of a value (enumeration attributes).</p>
1.30 cvs 1388:
1389: <p>Fixed-value attributes can either be <a href="#sectc325">global</a> or
1390: local to the element type for which they are fixed, but they must be declared
1391: before they are used.</p>
1392: <pre> FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 1393: FixedAttr = AttrID [ FixedOrModifVal ] .
1394: FixedOrModifVal = [ '?' ] '=' FixedValue .
1395: FixedValue = [ '-' ] NumValue / TextVal / AttrVal .
1396: NumValue = NUMBER .
1.18 cvs 1397: TextVal = STRING .</pre>
1398: </div>
1.1 cvs 1399:
1.18 cvs 1400: <div class="subsection">
1.37 ! cvs 1401: <h3><a name="sectc328" id="sectc328">Structure definitions</a></h3>
1.1 cvs 1402:
1.37 ! cvs 1403: <p>The structure of an element type can be a simple base type or a
! 1404: constructed type.</p>
1.30 cvs 1405:
1406: <p>For constructed types, it is frequently the case that similar structures
1.37 ! cvs 1407: appear in many places in a document. For example the contents of the
1.1 cvs 1408: abstract, of the introduction, and of a section can have the same structure,
1.37 ! cvs 1409: that of a sequence of paragraphs. In this case, a single, common structure
1.1 cvs 1410: can be defined (the paragraph sequence in this example), and the schema is
1411: written to indicate that each element type possesses this structure, as
1.18 cvs 1412: follows:</p>
1413: <pre> Abstract = Paragraph_sequence;
1.1 cvs 1414: Introduction = Paragraph_sequence;
1.18 cvs 1415: Section_contents = Paragraph_sequence;</pre>
1.30 cvs 1416:
1417: <p>The equals sign means ``has the same structure as''.</p>
1418:
1.37 ! cvs 1419: <p>If the element type defined is a simple base type, this is indicated by
! 1420: one of the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>, <tt>SYMBOL</tt>, or
! 1421: <tt>PICTURE</tt>. If some local attributes must be associated with a base
! 1422: type, the keyword of the base type is followed by the declaration of the
! 1423: local attributes using the syntax <a href="#sectc327">presented above.</a></p>
1.30 cvs 1424:
1425: <p>In the case of an open choice, the type is indicated by the keyword
1.18 cvs 1426: <tt>UNIT</tt> for units or the keyword <tt>NATURE</tt> for objects having a
1427: structure defined by any other schema.</p>
1.30 cvs 1428:
1429: <p>A unit represents one of the two following categories:</p>
1.18 cvs 1430: <ul>
1.30 cvs 1431: <li>a base type: text, graphical element, symbol, picture,</li>
1.37 ! cvs 1432: <li>an element whose type is chosen from among the types defined as units
! 1433: in the <tt>UNITS</tt> section of the document's structure schema. It can
1.30 cvs 1434: also be chosen from among the types defined as <a
1435: href="#sectd3132">units</a> in the <a href="#sectc3212"><tt>UNITS</tt>
1436: section</a> of the structure schemas that defines the ancestors of the
1437: element to which the rule is applied.</li>
1.18 cvs 1438: </ul>
1.30 cvs 1439:
1440: <p>Before the creation of an element defined as a unit, Thot asks the user to
1.18 cvs 1441: choose between the categories of elements.</p>
1.30 cvs 1442:
1443: <p>Thus, the contents of a paragraph can be specified as a sequence of units,
1.1 cvs 1444: which will permit the inclusion in the paragraphs of character strings,
1445: symbols, and various elements, such as cross-references, if these are defined
1.18 cvs 1446: as units.</p>
1.30 cvs 1447:
1.37 ! cvs 1448: <p>A schema object (keyword <tt>NATURE</tt>) represents an object defined by
! 1449: a structure schema freely chosen from among the available schemas; in the
! 1450: case the element type is defined by the first rule (the root rule) of the
! 1451: chosen schema.</p>
1.30 cvs 1452:
1453: <p>If the element type defined is a constructed type, the list, aggregate,
1.37 ! cvs 1454: choice, and reference constructors are used. In this case the definition
! 1455: begins with a keyword identifying the constructor. This keyword is followed
1.18 cvs 1456: by a syntax specific to each constructor.</p>
1.30 cvs 1457:
1458: <p>The local attribute definitions appear after the name of the element type
1.18 cvs 1459: being defined, if this element type has <a href="#sectc327">local
1460: attributes</a>.</p>
1461: <pre> Definition = BaseType [ LocAttrSeq ] / Constr / Element .
1.1 cvs 1462: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' / 'PICTURE' /
1463: 'UNIT' / 'NATURE' .
1464: Element = ElemID [ ExtOrDef ] .
1465: ExtOrDef = 'EXTERN' / 'INCLUDED' /
1466: [ LocAttrSeq ] '=' Definition .
1467: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
1468: '(' DefWithAttr ')' /
1469: 'BEGIN' DefOptSeq 'END' /
1470: 'AGGREGATE' DefOptSeq 'END' /
1471: 'CASE' 'OF' DefSeq 'END' /
1472: 'REFERENCE' '(' RefType ')' /
1.18 cvs 1473: 'PAIR' .</pre>
1.1 cvs 1474:
1.18 cvs 1475: <div class="subsubsection">
1.37 ! cvs 1476: <h4><a name="sectd3281" id="sectd3281">List</a></h4>
1.1 cvs 1477:
1.30 cvs 1478: <p>The list constructor permits the definition of an element type composed of
1.37 ! cvs 1479: a list of elements, all of the same type. A list definition begins with the
1.18 cvs 1480: <tt>LIST</tt> keyword followed by an optional range, the keyword <tt>OF</tt>,
1.1 cvs 1481: and the definition, between parentheses, of the element type which must
1.37 ! cvs 1482: compose the list. The optional range is composed of the minimum and maximum
1.1 cvs 1483: number of elements for the list separated by two periods and enclosed by
1.37 ! cvs 1484: brackets. If the range is not present, the number of list elements is
! 1485: unconstrained. When only one of the two bounds of the range is unconstrained,
! 1486: it is represented by a star ('*') character. Even when both bounds are
! 1487: unconstrained, they can be specified by <tt>[*..*]</tt>, but it is simpler
! 1488: not to specify any bound.</p>
1.18 cvs 1489: <pre> 'LIST' [ '[' min '..' max ']' ]
1.1 cvs 1490: 'OF' '(' DefWithAttr ')'
1491: min = Integer / '*' .
1492: max = Integer / '*' .
1.18 cvs 1493: Integer = NUMBER .</pre>
1.30 cvs 1494:
1495: <p>Before the document is edited, Thot creates the minimum number of elements
1.37 ! cvs 1496: for the list. If no minimum was given, it creates a single element. If a
1.30 cvs 1497: maximum number of elements is given and that number is attained, the editor
1498: refuses to create new elements for the list.</p>
1499:
1500: <blockquote class="example">
1501: <p><strong>Example:</strong></p>
1502:
1503: <p>The following two instructions define the body of a document as a
1504: sequence of at least two chapters and the contents of a section as a
1.37 ! cvs 1505: sequence of paragraphs. A single paragraph can be the entire contents of a
1.30 cvs 1506: section.</p>
1507: <pre>Body = LIST [2..*] OF (Chapter);
1.18 cvs 1508: Section_contents = LIST OF (Paragraph);</pre>
1509: </blockquote>
1510: </div>
1.1 cvs 1511:
1.18 cvs 1512: <div class="subsubsection">
1.37 ! cvs 1513: <h4><a name="sectd3282" id="sectd3282">Aggregate</a></h4>
1.1 cvs 1514:
1.37 ! cvs 1515: <p>The aggregate constructor is used to define an element type as a
! 1516: collection of sub-elements, each having a fixed type. The collection may be
! 1517: ordered or unordered. The elements composing the collection are called
! 1518: <em>components</em>. In the definition of an aggregate, a keyword indicates
1.18 cvs 1519: whether or not the aggregate is ordered: <tt>BEGIN</tt> for an ordered
1520: aggregate, <tt>AGGREGATE</tt> for an unordered aggregate. This keyword is
1.1 cvs 1521: followed by the list of component type definitions which is terminated by the
1.37 ! cvs 1522: <tt>END</tt> keyword. The component type definitions are separated by
1.18 cvs 1523: commas.</p>
1.30 cvs 1524:
1525: <p>Before creating an aggregate, the Thot editor creates all the aggregate's
1.1 cvs 1526: components in the order they appear in the structure schema, even for
1.37 ! cvs 1527: unordered aggregates. However, unlike ordered aggregates, the components of
1.1 cvs 1528: an unordered aggregate may be rearranged using operations of the Thot editor.
1529: The exceptions to the rule are any components whose name was preceded by a
1.37 ! cvs 1530: question mark character ('?'). These components, which are optional, can be
1.1 cvs 1531: created by explicit request, possibly at the time the aggregate is created,
1.18 cvs 1532: but they are not created automatically <em>prior</em> to the creation of the
1533: aggregate.</p>
1534: <pre> 'BEGIN' DefOptSeq 'END'
1.30 cvs 1535: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.18 cvs 1536: DefOpt = [ '?' ] DefWithAttr .</pre>
1.30 cvs 1537:
1.18 cvs 1538: <blockquote class="example">
1.30 cvs 1539: <p><strong>Example:</strong></p>
1540:
1541: <p>In a bilingual document, each paragraph has an English version and a
1.37 ! cvs 1542: French version. In certain cases, the translator wants to add a marginal
! 1543: note, but this note is present in very few paragraphs. Thus, it must not be
! 1544: created systematically for every paragraph. A bilingual paragraph of this
1.30 cvs 1545: type is declared:</p>
1546: <pre>Bilingual_paragraph = BEGIN
1.1 cvs 1547: French_paragraph = TEXT;
1548: English_paragraph = TEXT;
1549: ? Note = TEXT;
1.18 cvs 1550: END;</pre>
1551: </blockquote>
1552: </div>
1.1 cvs 1553:
1.18 cvs 1554: <div class="subsubsection">
1.37 ! cvs 1555: <h4><a name="sectd3283" id="sectd3283">Choice</a></h4>
1.1 cvs 1556:
1.30 cvs 1557: <p>The choice constructor permits the definition of an element type which is
1.37 ! cvs 1558: chosen from among a set of possible types. The keywords <tt>CASE</tt> and
! 1559: <tt>OF</tt> are followed by a list of definitions of possible types, which
! 1560: are separated by semicolons and terminated by the <tt>END</tt> keyword.</p>
1.18 cvs 1561: <pre> 'CASE' 'OF' DefSeq 'END'
1.30 cvs 1562: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .</pre>
1563:
1564: <p>Before the creation of an element defined as a choice, the Thot editor
1.37 ! cvs 1565: presents the list of possible types for the element to the user. The user has
1.18 cvs 1566: only to select the element type that s/he wants to create from this list.</p>
1.30 cvs 1567:
1.37 ! cvs 1568: <p>The order of the type declarations is important. It determines the order
! 1569: of the list presented to the user before the creation of the element. Also,
1.30 cvs 1570: when a Choice element is being created automatically, the first type in the
1.37 ! cvs 1571: list is used. In fact, using the Thot editor, when an empty Choice element is
1.1 cvs 1572: selected, it is possible to select this element and to enter its text from
1573: keyboard. In this case, the editor uses the first element type which can
1.18 cvs 1574: contain an atom of the character string type.</p>
1.30 cvs 1575:
1576: <p>The two special cases of the choice constructor, the <a
1.18 cvs 1577: href="#sectc328"><em>schema</em></a> and the <a
1578: href="#sectc3212"><em>unit</em></a> are discussed elsewhere.</p>
1.30 cvs 1579:
1.18 cvs 1580: <blockquote class="example">
1.30 cvs 1581: <p><strong>Example:</strong></p>
1582:
1583: <p>It is common in documents to treat a variety of objects as if they were
1.37 ! cvs 1584: ordinary paragraphs. Thus, a ``Paragraph'' might actually be composed of a
1.30 cvs 1585: block of text (an ordinary paragraph), or a mathematical formula whose
1586: structure is defined by another structure schema named Math, or a table,
1.37 ! cvs 1587: also defined by another structure schema. Here is a definition of such a
1.30 cvs 1588: paragraph:</p>
1589: <pre>Paragraph = CASE OF
1.1 cvs 1590: Simple_text = TEXT;
1591: Formula = Math;
1592: Table_para = Table;
1.18 cvs 1593: END;</pre>
1594: </blockquote>
1595: </div>
1.1 cvs 1596:
1.18 cvs 1597: <div class="subsubsection">
1.37 ! cvs 1598: <h4><a name="sectd3284" id="sectd3284">Reference</a></h4>
1.1 cvs 1599:
1.37 ! cvs 1600: <p>Like all elements in Thot, references are typed. An element type defined
1.30 cvs 1601: as a reference is a cross-reference to an element of some other given type.
1602: The keyword <tt>REFERENCE</tt> is followed by the name of a type enclosed in
1.37 ! cvs 1603: parentheses. When the type which is being cross-referenced is defined in
1.1 cvs 1604: another structure schema, the type name is itself followed by the name of the
1.18 cvs 1605: external structure schema in which it is defined.</p>
1.30 cvs 1606:
1607: <p>When the designated element type is a <a href="#sectd3285">mark pair</a>,
1.37 ! cvs 1608: it can be preceded by a <tt>FIRST</tt> or <tt>SECOND</tt> keyword. These
1.18 cvs 1609: keywords indicate whether the reference points to the first or second mark of
1610: the pair. If the reference points to a pair and neither of these two keywords
1611: is present, the reference is considered to point to the first mark of the
1612: pair.</p>
1.30 cvs 1613:
1.37 ! cvs 1614: <p>There is an exception to the principle of typed references: it is possible
1.30 cvs 1615: to define a reference which designates an element of any type, which can
1616: either be in the same document or another document. In this case, it suffices
1617: to put the keyword <tt>ANY</tt> in the parentheses which indicate the
1618: referenced element type.</p>
1.18 cvs 1619: <pre> 'REFERENCE' '(' RefType ')'
1620: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .</pre>
1.30 cvs 1621:
1622: <p>When defining an inclusion, the <tt>REFERENCE</tt> keyword is not used.
1.1 cvs 1623: Inclusions with complete expansion are not declared as such in the structure
1.37 ! cvs 1624: schemas, since any element defined in a structure schema can be replaced by
! 1625: an element of the same type. Instead, inclusions without expansion or with
1.1 cvs 1626: partial expansion must be declared explicitly whenever they will include a
1.37 ! cvs 1627: complete object ( and not a part of an object). In this case, the object type
1.1 cvs 1628: to be included (that is, the name of its structure schema) is followed by a
1.37 ! cvs 1629: keyword: <tt>EXTERN</tt> for inclusion without expansion and
! 1630: <tt>INCLUDED</tt> for partial expansion.</p>
1.30 cvs 1631:
1.37 ! cvs 1632: <p>Before creating a cross-reference or an inclusion, the Thot editor asks
! 1633: the user to choose, from the document images displayed, the referenced or
! 1634: included element.</p>
1.30 cvs 1635:
1.18 cvs 1636: <blockquote class="example">
1.30 cvs 1637: <p><strong>Example:</strong></p>
1638:
1639: <p>If the types Note and Section are defined in the Article structure
1640: schema, it is possible to define, in the same structure schema, a reference
1641: to a note and a reference to a section in this manner:</p>
1642: <pre>Ref_note = REFERENCE (Note);
1.18 cvs 1643: Ref_section = REFERENCE (Section);</pre>
1.30 cvs 1644:
1645: <p>It is also possible to define the generic structure of a collection of
1646: articles, which include (with partial expansion) objects of the Article
1647: class and which possess an introduction which may include cross-references
1.37 ! cvs 1648: to sections of the included articles. In the Collection structure schema,
1.30 cvs 1649: the definitions are:</p>
1650: <pre>Collection = BEGIN
1.6 cvs 1651: Collection_title = TEXT;
1652: Introduction = LIST OF (Elem = CASE OF
1.1 cvs 1653: TEXT;
1654: Ref_sect;
1655: END);
1.6 cvs 1656: Body = LIST OF (Article INCLUDED);
1657: END;
1.18 cvs 1658: Ref_sect = REFERENCE (Section (Article));</pre>
1.30 cvs 1659:
1660: <p>Here we define a Folder document class which has a title and includes
1661: documents of different types, particularly Folders:</p>
1662: <pre>Folder = BEGIN
1.6 cvs 1663: Folder_title = TEXT;
1664: Folder_contents = LIST OF (Document);
1665: END;
1.1 cvs 1666:
1667: Document = CASE OF
1668: Article EXTERN;
1669: Collection EXTERN;
1670: Folder EXTERN;
1.18 cvs 1671: END;</pre>
1.30 cvs 1672:
1673: <p>Under this definition, Folder represents either an aggregate which
1674: contains a folder title and the list of included documents or an included
1.37 ! cvs 1675: folder. To resolve this ambiguity, in the P language, the placement of a
1.30 cvs 1676: star character in front of the type name (here, Folder) indicates an
1677: included document.</p>
1.18 cvs 1678: </blockquote>
1679: </div>
1.1 cvs 1680:
1.18 cvs 1681: <div class="subsubsection">
1.37 ! cvs 1682: <h4><a name="sectd3285" id="sectd3285">Mark pairs</a></h4>
1.1 cvs 1683:
1.37 ! cvs 1684: <p>Like other elements, mark pairs are typed. The two marks of the pair have
! 1685: the same type, but there exist two predefined subtypes which apply to all
! 1686: mark pairs: the first mark of the pair (called <tt>First</tt> in the P and T
1.18 cvs 1687: languages) and the second mark (called <tt>Second</tt>).</p>
1.30 cvs 1688:
1689: <p>In the S language, a mark pair is noted simply by the <tt>PAIR</tt>
1.18 cvs 1690: keyword.</p>
1.30 cvs 1691:
1.37 ! cvs 1692: <p>In the Thot editor, marks are always moved or destroyed together. The two
1.1 cvs 1693: marks of a pair have the same identifier, unique within the document, which
1.18 cvs 1694: permits intertwining mark pairs without risk of ambiguity.</p>
1695: </div>
1696: </div>
1.1 cvs 1697:
1.18 cvs 1698: <div class="subsection">
1.37 ! cvs 1699: <h3><a name="sectc329" id="sectc329">Imports</a></h3>
1.1 cvs 1700:
1.30 cvs 1701: <p>Because of schema constructors, it is possible, before editing a document,
1.37 ! cvs 1702: to use classes defined by other structure schemas whenever they are needed.
! 1703: It is also possible to assign specific document classes to certain element
! 1704: types. In this case, these classes are simply designated by their name. In
! 1705: fact, if a type name is not defined in the structure schema, it is assumed
! 1706: that it specifies a structure defined by another structure schema.</p>
1.30 cvs 1707:
1.18 cvs 1708: <blockquote class="example">
1.30 cvs 1709: <p><strong>Example:</strong></p>
1710:
1711: <p>If the types Math and Table don't appear in the left part of a structure
1712: rule in the schema, the following two rules indicate that a formula has the
1.37 ! cvs 1713: structure of an object defined by the structure schema Math and that a
! 1714: table element has the structure of an object defined by the Table
! 1715: schema.</p>
1.30 cvs 1716: <pre>Formula = Math;
1.18 cvs 1717: Table_elem = Table;</pre>
1718: </blockquote>
1719: </div>
1720:
1721: <div class="subsection">
1.37 ! cvs 1722: <h3><a name="sectc3210" id="sectc3210">Extension rules</a></h3>
1.18 cvs 1723:
1.30 cvs 1724: <p>The <tt>EXTENS</tt> section, which can only appear in an extension schema,
1.1 cvs 1725: defines complements to the rules in the primary schema (i.e. the structure
1726: schema to which the extension schema will be applied). More precisely, this
1727: section permits the addition to an existing type of local attributes,
1.18 cvs 1728: extensions, restrictions and fixed-value attributes.</p>
1.30 cvs 1729:
1730: <p>These additions can be applied to the root rule of the primary schema,
1.18 cvs 1731: designated by the keyword <tt>Root</tt>, or to any other explicitly named
1732: rule.</p>
1.30 cvs 1733:
1734: <p>Extension rules are separated from each other by a semicolon and each
1.18 cvs 1735: extension rule has the same syntax as a <a href="#sectc327">structure
1736: rule</a>, but the part which defines the constructor is absent.</p>
1.30 cvs 1737: <pre> ExtenRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.6 cvs 1738: ExtensRule = RootOrElem [ LocAttrSeq ]
1739: [ '+' '(' ExtensionSeq ')' ]
1740: [ '-' '(' RestrictSeq ')' ]
1741: [ 'WITH' FixedAttrSeq ] .
1.18 cvs 1742: RootOrElem = 'Root' / ElemID .</pre>
1743: </div>
1.1 cvs 1744:
1.18 cvs 1745: <div class="subsection">
1.37 ! cvs 1746: <h3><a name="sectc3212" id="sectc3212">Units</a></h3>
1.30 cvs 1747:
1748: <p>The <tt>UNITS</tt> section of the structure schema contains the
1749: declarations of the element types which can be used in the external objects
1750: making up parts of the document or in objects of the class defined by the
1.37 ! cvs 1751: schema. These element types are defined just like other structured element
! 1752: types. They can be used in the other element types of the schema, but they
! 1753: can also be used in any other rule of the schema.</p>
1.30 cvs 1754:
1755: <blockquote class="example">
1756: <p><strong>Example:</strong></p>
1.1 cvs 1757:
1.30 cvs 1758: <p>If references to notes are declared as units:</p>
1759: <pre>UNITS
1.18 cvs 1760: Ref_note = REFERENCE (Note);</pre>
1.30 cvs 1761:
1.37 ! cvs 1762: <p>then it is possible to use references to notes in a cell of a table,
! 1763: even when <tt>Table</tt> is an external structure schema. The
! 1764: <tt>Table</tt> schema must declare a cell to be a sequence of units, which
! 1765: can then be base element types (text, for example) or references to notes
! 1766: in the document.</p>
1.30 cvs 1767: <pre>Cell = LIST OF (UNITS);</pre>
1.18 cvs 1768: </blockquote>
1769: </div>
1.1 cvs 1770:
1.18 cvs 1771: <div class="subsection">
1.37 ! cvs 1772: <h3><a name="sectc3213" id="sectc3213">Skeleton elements</a></h3>
1.1 cvs 1773:
1.30 cvs 1774: <p>When editing a document which contains or must contain external references
1775: to several other documents, it may be necessary to load a large number of
1.1 cvs 1776: documents, simply to see the parts designated by the external references of
1.37 ! cvs 1777: the document while editing, or to access the source of included elements. In
! 1778: this case, the external documents are not modified and it is only necessary
! 1779: to see the elements of these documents which could be referenced. Because of
1.1 cvs 1780: this, the editor will suggest that the documents be loaded in ``skeleton''
1.37 ! cvs 1781: form. This form contains only the elements of the document explicitly
1.18 cvs 1782: mentioned in the <tt>EXPORT</tt> section of their structure schema and, for
1.1 cvs 1783: these elements, only the part of the contents specified in that section. This
1784: form has the advantage of being very compact, thus requiring very few
1.37 ! cvs 1785: resources from the editor. This is also the skeleton form which constitutes
1.18 cvs 1786: the expanded form of <a href="#inclusion">inclusions</a> with partial
1787: expansion.</p>
1.30 cvs 1788:
1789: <p>Skeleton elements must be declared explicitly in the <tt>EXPORT</tt>
1.37 ! cvs 1790: section of the structure schema that defines them. This section begins with
1.30 cvs 1791: the keyword <tt>EXPORT</tt> followed by a comma-separated list of the element
1.1 cvs 1792: types which must appear in the skeleton form and ending with a semicolon.
1.18 cvs 1793: These types must have been previously declared in the schema.</p>
1.30 cvs 1794:
1.37 ! cvs 1795: <p>For each skeleton element type, the part of the contents which is loaded
! 1796: by the editor, and therefore displayable, can be specified by putting the
! 1797: keyword <tt>WITH</tt> and the name of the contained element type to be loaded
! 1798: after the name of the skeleton element type. In this case only that named
! 1799: element, among all the elements contained in the exportable element type,
! 1800: will be loaded. If the <tt>WITH</tt> is absent, the entire contents of the
! 1801: skeleton element will be loaded by the editor. If instead, it is better that
! 1802: the skeleton form not load the contents of a particular element type, the
! 1803: keyword <tt>WITH</tt> must be followed by the word <tt>Nothing</tt>.</p>
1.18 cvs 1804: <pre> [ 'EXPORT' SkeletonSeq ]
1.1 cvs 1805:
1.30 cvs 1806: SkeletonSeq = SkelElem < ',' SkelElem > ';' .
1.1 cvs 1807: SkelElem = ElemID [ 'WITH' Contents ] .
1.18 cvs 1808: Contents = 'Nothing' / ElemID [ ExtStruct ] .</pre>
1.30 cvs 1809:
1.18 cvs 1810: <blockquote class="example">
1.30 cvs 1811: <p><strong>Example:</strong></p>
1812:
1813: <p>Suppose that, in documents of the article class, the element types
1814: Article_title, Figure, Section, Paragraph, and Biblio should appear in the
1815: skeleton form in order to make it easier to create external references to
1.37 ! cvs 1816: them from other documents. When loading an article in its skeleton form,
1.30 cvs 1817: all of these element types will be loaded except for paragraphs, but only
1.37 ! cvs 1818: the article title will be loaded in its entirety. For figures, the caption
1.30 cvs 1819: will be loaded, while for sections, the title will be loaded, and for
1.37 ! cvs 1820: bibliographic entries, only the title that they contain will be loaded.
! 1821: Note that bibliographic elements are defined in another structure schema,
! 1822: RefBib. To produce this result, the following declarations should be placed
! 1823: in the Article structure schema:</p>
1.30 cvs 1824: <pre>EXPORT
1.1 cvs 1825: Article_title,
1.5 cvs 1826: Figure With Caption,
1.1 cvs 1827: Section With Section_title,
1828: Paragraph With Nothing,
1.18 cvs 1829: Biblio With Biblio_title(RefBib);</pre>
1830: </blockquote>
1831: </div>
1.1 cvs 1832:
1.18 cvs 1833: <div class="subsection">
1.37 ! cvs 1834: <h3><a name="sectc3214" id="sectc3214">Exceptions</a></h3>
1.1 cvs 1835:
1.30 cvs 1836: <p>The behavior of the Thot editor and the actions that it performs are
1.37 ! cvs 1837: determined by the structure schemas. These actions are applied to all
! 1838: document and object types in accordance with their generic structure. For
1.1 cvs 1839: certain object types, such as tables and graphics, these actions are not
1840: sufficient or are poorly adapted and some special actions must be added to or
1.37 ! cvs 1841: substituted for certain standard actions. These special actions are called
1.18 cvs 1842: <em>exceptions</em>.</p>
1.30 cvs 1843:
1.37 ! cvs 1844: <p>Exceptions only inhibit or modify certain standard actions, but they can
! 1845: be used freely in every structure schema.</p>
1.30 cvs 1846:
1.37 ! cvs 1847: <p>Each structure schema can contain a section defining exceptions. It begins
1.18 cvs 1848: with the keyword <tt>EXCEPT</tt> and is composed of a sequence of exception
1.37 ! cvs 1849: declarations, separated by semicolons. Each declaration of an exception
! 1850: begins with the name of an element type or attribute followed by a colon.
! 1851: This indicates the element type or attribute to which the following
! 1852: exceptions apply. When the given element type name is a <a
! 1853: href="#sectd3285">mark pair</a>, and only in this case, the type name can be
! 1854: preceded by the keyword <tt>First</tt> or <tt>Second</tt>, to indicate if the
! 1855: exceptions which follow are associated with the first mark of the pair or the
! 1856: second. In the absence of this keyword, the first mark is used.</p>
1.30 cvs 1857:
1858: <p>When placed in an <a href="#sectc322">extension schema</a>, the keyword
1.18 cvs 1859: <tt>EXTERN</tt> indicates that the type name which follows is found in the
1.37 ! cvs 1860: principal schema (the schema being extended by the extension schema). The
! 1861: exceptions are indicated by a name. They are separated by semicolons.</p>
1.18 cvs 1862: <pre> [ 'EXCEPT' ExceptSeq ]
1.1 cvs 1863:
1.30 cvs 1864: ExceptSeq = Except ';' < Except ';' > .
1.1 cvs 1865: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr
1866: ':' ExcValSeq .
1867: ExcTypeOrAttr = ElemID / AttrID .
1.30 cvs 1868: ExcValSeq = ExcValue < ',' ExcValue > .
1.19 cvs 1869: ExcValue ='NoCut' / 'NoCreate' / 'NoHMove' /
1870: 'NoVMove' / 'NoHResize' / 'NoVResize' /
1871: 'NoMove' / 'NoResize' / 'MoveResize' /
1872: 'NewWidth' / 'NewHeight' / 'NewHPos' /
1873: 'NewVPos' / 'Invisible' /
1.28 cvs 1874: 'NoSelect' / 'NoSpellCheck' /
1.1 cvs 1875: 'Hidden' / 'ActiveRef' /
1876: 'ImportLine' / 'ImportParagraph' /
1877: 'NoPaginate' / 'ParagraphBreak' /
1.19 cvs 1878: 'PageBreak' / 'PageBreakAllowed' / 'PageBreakPlace' /
1879: 'PageBreakRepetition' / 'PageBreakRepBefore' /
1.9 cvs 1880: 'HighlightChildren' / 'ExtendedSelection' /
1.36 cvs 1881: 'SelectParent' / 'ClickableSurface' /
1.29 cvs 1882: 'ReturnCreateNL' / 'ReturnCreateWithin' /
1883: 'IsDraw' / 'IsTable' /
1.19 cvs 1884: 'IsRow' / 'IsColHead' / 'IsCell' /
1885: 'NewPercentWidth' / 'ColRef' / 'ColSpan' /
1886: 'RowSpan' / 'SaveDocument' / 'Shadow' .</pre>
1.30 cvs 1887:
1888: <p>The following are the available exceptions:</p>
1.18 cvs 1889: <dl>
1.30 cvs 1890: <dt><tt>NoCut</tt></dt>
1.37 ! cvs 1891: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1892: type to which this exception is applied cannot be deleted by the
1893: editor.</dd>
1894: <dt><tt>NoCreate</tt></dt>
1.37 ! cvs 1895: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1896: type to which this exception is applied cannot be created by ordinary
1.37 ! cvs 1897: commands for creating new elements. These elements are usually created
1.30 cvs 1898: by special actions associated with other exceptions.</dd>
1899: <dt><tt>NoHMove</tt></dt>
1.37 ! cvs 1900: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1901: type to which this exception is applied cannot be moved horizontally
1902: with the mouse. Their children elements cannot be moved either.</dd>
1903: <dt><tt>NoVMove</tt></dt>
1.37 ! cvs 1904: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1905: type to which this exception is applied cannot be moved vertically with
1906: the mouse. Their children elements cannot be moved either.</dd>
1907: <dt><tt>NoMove</tt></dt>
1.37 ! cvs 1908: <dd>This exception can only be applied to element types. Elements of a
! 1909: type to which this exception is applied cannot be moved in any
! 1910: direction with the mouse. Their children elements cannot be moved
! 1911: either.</dd>
1.30 cvs 1912: <dt><tt>NoHResize</tt></dt>
1.37 ! cvs 1913: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1914: type to which this exception is applied cannot be resized horizontally
1915: with the mouse. Their children elements cannot be resized either.</dd>
1916: <dt><tt>NoVResize</tt></dt>
1.37 ! cvs 1917: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1918: type to which this exception is applied cannot be resized vertically
1919: with the mouse. Their children elements cannot be resized either.</dd>
1920: <dt><tt>NoResize</tt></dt>
1.37 ! cvs 1921: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1922: type to which this exception is applied cannot be resized in any
1.37 ! cvs 1923: direction with the mouse. Their children elements cannot be resized
1.30 cvs 1924: either.</dd>
1925: <dt><tt>MoveResize</tt></dt>
1.37 ! cvs 1926: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1927: type to which this exception is applied can be moved and resized in any
1928: direction with the mouse, even if one of their ancestor element has an
1.37 ! cvs 1929: exception that prevents moving or resizing. Their children elements can
1.30 cvs 1930: also be resized or moved.</dd>
1931: <dt><tt>NewWidth</tt></dt>
1.37 ! cvs 1932: <dd>This exception can only be applied to numeric attributes. If the
! 1933: width of an element which has this attribute is modified with the
! 1934: mouse, the value of the new width will be assigned to the
! 1935: attribute.</dd>
1.30 cvs 1936: <dt><tt>NewHeight</tt></dt>
1.37 ! cvs 1937: <dd>This exception can only be applied to numeric attributes. If the
1.30 cvs 1938: height of an element which has this attribute is modified with the
1939: mouse, the value of the new height will be assigned to the
1940: attribute.</dd>
1941: <dt><tt>NewHPos</tt></dt>
1.37 ! cvs 1942: <dd>This exception can only be applied to numeric attributes. If the
1.30 cvs 1943: horizontal position of an element which has this attribute is modified
1944: with the mouse, the value of the new horizontal position will be
1945: assigned to the attribute.</dd>
1946: <dt><tt>NewVPos</tt></dt>
1.37 ! cvs 1947: <dd>This exception can only be applied to numeric attributes. If the
1.30 cvs 1948: vertical position of an element which has this attribute is modified
1949: with the mouse, the value of the new vertical position will be assigned
1950: to the attribute.</dd>
1951: <dt><tt>Invisible</tt></dt>
1952: <dd>This exception can only be applied to attributes, but can be applied
1.37 ! cvs 1953: to all attribute types. It indicates that the attribute must not be
! 1954: seen by the user and that its value must not be changed directly. This
1.30 cvs 1955: exception is usually used when another exception manipulates the value
1956: of an attribute.</dd>
1957: <dt><tt>NoSelect</tt></dt>
1.37 ! cvs 1958: <dd>This exception can only be applied to element types. Elements of a
! 1959: type to which this exception is applied cannot be selected directly
1.30 cvs 1960: with the mouse, but they can be selected by other methods provided by
1961: the editor.</dd>
1962: <dt>NoSpellCheck</dt>
1.37 ! cvs 1963: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 1964: type to which this exception is applied are not taken into account by
1965: the spell checker.</dd>
1966: <dt><tt>Hidden</tt></dt>
1.37 ! cvs 1967: <dd>This exception can only be applied to element types. It indicates
1.30 cvs 1968: that elements of this type, although present in the document's
1.37 ! cvs 1969: structure, must not be shown to the user of the editor. In particular,
1.30 cvs 1970: the creation menus must not propose this type and the selection message
1971: must not pick it.</dd>
1972: <dt><tt>ActiveRef</tt></dt>
1973: <dd>This exception can only be applied to attributes of the reference
1.37 ! cvs 1974: type. It indicates that when the user of the editor makes a double
1.30 cvs 1975: click on an element which possesses a reference attribute having this
1976: exception, the element designated by the reference attribute will be
1977: selected.</dd>
1978: <dt><tt>ImportLine</tt></dt>
1.37 ! cvs 1979: <dd>This exception can only be applied to element types. It indicates
1.30 cvs 1980: that elements of this type should receive the content of imported text
1.37 ! cvs 1981: files. An element is created for each line of the imported file. A
1.30 cvs 1982: structure schema cannot contain several exceptions <tt>ImportLine</tt>
1983: and, if it contains one, it should not contain any exception
1984: <tt>ImportParagraph</tt>.</dd>
1985: <dt><tt>ImportParagraph</tt></dt>
1.37 ! cvs 1986: <dd>This exception can only be applied to element types. It indicates
1.30 cvs 1987: that elements of this type should receive the content of imported text
1.37 ! cvs 1988: files. An element is created for each paragraph of the imported file. A
! 1989: paragraph is a sequence of lines without any empty line. A structure
1.30 cvs 1990: schema cannot contain several exceptions <tt>ImportParagraph</tt> and,
1991: if it contains one, it should not contain any exception
1992: <tt>ImportLine</tt>.</dd>
1993: <dt><tt>NoPaginate</tt></dt>
1994: <dd>This exception can only be applied to the root element, i.e. the name
1.37 ! cvs 1995: that appear after the keyword <tt>STRUCTURE</tt> at the beginning of
! 1996: the structure schema. It indicates that the editor should not allow the
1.30 cvs 1997: user to paginate documents of that type.</dd>
1998: <dt><tt>ParagraphBreak</tt></dt>
1.37 ! cvs 1999: <dd>This exception can only be applied to element types. When the caret
! 2000: is within an element of a type to which this exception is applied, it
! 2001: is that element that will be split when the user hits the Return
! 2002: key.</dd>
1.30 cvs 2003: <dt><tt>ReturnCreateNL</tt></dt>
1.37 ! cvs 2004: <dd>This exception can only be applied to element types. When the caret
1.30 cvs 2005: is within an element of a type to which this exception is applied, the
2006: Return key simply inserts a New line character (code \212) at the
2007: current position. The Return key does not create a new element; it does
2008: not split the current element either.</dd>
2009: <dt><tt>ReturnCreateWithin</tt></dt>
1.37 ! cvs 2010: <dd>This exception can only be applied to element types. When the caret
1.30 cvs 2011: is within an element of a type to which this exception is applied, the
2012: Return key will create a new element within that element, not a sibling
2013: after that element.</dd>
2014: <dt><tt>HighlightChildren</tt></dt>
1.37 ! cvs 2015: <dd>This exception can only be applied to element types. Elements of a
1.30 cvs 2016: type to which this exception is applied are not highlighted themselves
1.32 cvs 2017: when they are selected in the main view, but all their children are
1.37 ! cvs 2018: highlighted instead. If children have this exception too, the process
! 2019: is applied recursively. Only the main view defined in the presentation
1.32 cvs 2020: schema is concerned. Tee exception is ignored for other views.</dd>
1.30 cvs 2021: <dt><tt>ExtendedSelection</tt></dt>
1.37 ! cvs 2022: <dd>This exception can only be applied to element types. The selection
1.30 cvs 2023: extension command (middle button of the mouse) only add the clicked
2024: element (if it has that exception) to the current selection, without
2025: selecting other elements between the current selection and the clicked
2026: element.</dd>
1.36 cvs 2027: <dt><code>SelectParent</code></dt>
2028: <dd>This exception can only be applied to element types. When the user
1.37 ! cvs 2029: clicks on an element of that type, the parent of the element is
! 2030: selected instead of the element itself.</dd>
1.36 cvs 2031: <dt><code>ClickableSurface</code></dt>
2032: <dd>This exception can only be applied to element types. When the user
1.37 ! cvs 2033: clicks within a child of an element of that type, this child is
! 2034: selected even if it is a graphic leaf that is not filled.</dd>
1.36 cvs 2035: <dt><code>IsDraw</code>, <code>IsTable</code>, <code>IsColHead</code>,
2036: <code>IsRow</code>, <code>IsCell</code></dt>
1.37 ! cvs 2037: <dd>These exceptions can only be applied to element types. Elements of a
1.30 cvs 2038: type to which these exceptions are applied are identified as Draws,
2039: Tables, Colheads, Rows or Cells and specific processing are applied to
2040: them.</dd>
1.36 cvs 2041: <dt><code>ColRef</code></dt>
1.30 cvs 2042: <dd>This exception can only be applied to attributes of the reference
2043: type. It indicates that this attribute refers to the column head (see
2044: exception IsColHead) which the element belongs to.</dd>
1.36 cvs 2045: <dt><code>ColSpan</code>, <code>RowSpan</code></dt>
1.31 cvs 2046: <dd>These exceptions can only be applied to numeric attributes of cells.
1.30 cvs 2047: They indicate that attribute values give how many columns or rows the
2048: element spans.</dd>
1.36 cvs 2049: <dt><code>Shadow</code></dt>
1.37 ! cvs 2050: <dd>This exception can only be applied to element types. Text of elements
1.30 cvs 2051: of a type to which this exception is applied are displayed and printed
2052: as a set of stars ('*').</dd>
1.18 cvs 2053: </dl>
1.30 cvs 2054:
1.18 cvs 2055: <blockquote class="example">
1.30 cvs 2056: <p><strong>Example:</strong></p>
2057:
2058: <p>Consider a structure schema for object-style graphics which defines the
2059: Graphic_object element type with the associated Height and Weight numeric
1.37 ! cvs 2060: attributes. Suppose that we want documents of this class to have the
1.30 cvs 2061: following qualities:</p>
2062: <ul>
2063: <li>Whenever the width or height of an object is changed using the mouse,
2064: the new values are stored in the object's Width and Height
2065: attributes.</li>
2066: <li>The user should not be able to change the values of the Width and
2067: Height attributes via the Attributes menu of the Thot editor.</li>
2068: </ul>
2069:
2070: <p>The following exceptions will produce this effect.</p>
2071: <pre>STRUCT
1.1 cvs 2072: ...
1.5 cvs 2073: Graphics_object (ATTR Height = Integer; Width = Integer)
1.1 cvs 2074: = GRAPHICS with Height ?= 10, Width ?= 10;
2075: ...
2076: EXCEPT
2077: Height: NewHeight, Invisible;
1.18 cvs 2078: Width: NewWidth, Invisible;</pre>
2079: </blockquote>
2080: </div>
2081: </div>
1.1 cvs 2082:
1.18 cvs 2083: <div class="section">
1.37 ! cvs 2084: <h2><a name="sectb33" id="sectb33">Some examples</a></h2>
1.1 cvs 2085:
1.30 cvs 2086: <p>In order to illustrate the principles of the document model and the syntax
2087: of the S language, this section presents two examples of structure schemas.
2088: One defines a class of documents, the other defines a class of objects.</p>
1.1 cvs 2089:
1.18 cvs 2090: <div class="subsection">
1.37 ! cvs 2091: <h3><a name="sectc331" id="sectc331">A class of documents: articles</a></h3>
1.1 cvs 2092:
1.30 cvs 2093: <p>This example shows a possible structure for articles published in a
2094: journal. Text between braces is comments.</p>
1.18 cvs 2095: <pre>STRUCTURE Article; { This schema defines the Article class }
1.1 cvs 2096: DEFPRES ArticleP; { The default presentation schema is
2097: ArticleP }
2098: ATTR { Global attribute definitions }
2099: WordType = Definition, IndexWord, DocumentTitle;
2100: { A single global attribute is defined, with three values }
2101: STRUCT { Definition of the generic structure }
2102: Article = BEGIN { The Article class has an aggregate
2103: structure }
2104: Title = BEGIN { The title is an aggregate }
2105: French_title =
2106: Text WITH Language='Fran\347ais';
2107: English_title =
2108: Text WITH Language='English';
2109: END;
2110: Authors =
2111: LIST OF (Author
2112: (ATTR Author_type=principal,secondary)
2113: { The Author type has a local attribute }
2114: = BEGIN
2115: Author_name = Text;
2116: Info = Paragraphs ;
2117: { Paragraphs is defined later }
2118: Address = Text;
2119: END
2120: );
2121: Keywords = Text;
2122: { The journal's editor introduces the article
2123: with a short introduction, in French and
2124: in English }
2125: Introduction =
2126: BEGIN
2127: French_intr = Paragraphs WITH
2128: Language='Fran\347ais';
2129: English_intr = Paragraphs WITH
2130: Language='English';
2131: END;
2132: Body = Sections; { Sections are defined later }
2133: { Appendixes are only created on demand }
2134: ? Appendices =
2135: LIST OF (Appendix =
2136: BEGIN
2137: Appendix_Title = Text;
2138: Appendix_Contents = Paragraphs;
2139: END
2140: );
1.37 ! cvs 2141: ? Figures = LIST OF (Figure);
! 2142: ? Bibliography = LIST OF (Biblio_citation);
! 2143: ? Notes = LIST OF (Note);
1.1 cvs 2144: END; { End of the Article aggregate }
2145:
2146: Sections = LIST [2..*] OF (
2147: Section = { At least 2 sections }
2148: BEGIN
2149: Section_title = Text;
2150: Section_contents =
2151: BEGIN
2152: Paragraphs;
2153: Sections; { Sections at a lower level }
2154: END;
2155: END
2156: );
2157:
2158: Paragraphs = LIST OF (Paragraph = CASE OF
2159: Enumeration =
2160: LIST [2..*] OF
2161: (Item = Paragraphs);
2162: Isolated_formula = Formula;
2163: LIST OF (UNIT);
2164: END
2165: );
2166:
2167: Figure = BEGIN
1.5 cvs 2168: Figure_caption = Text;
1.1 cvs 2169: Illustration = NATURE;
2170: END;
2171:
2172: Biblio_citation = CASE OF
2173: Ref_Article =
2174: BEGIN
2175: Authors_Bib = Text;
2176: Article_Title = Text;
2177: Journal = Text;
2178: Page_Numbers = Text;
2179: Date = Text;
2180: END;
2181: Ref_Livre =
2182: BEGIN
2183: Authors_Bib; { Defined above }
2184: Book_Title = Text;
2185: Editor = Text;
2186: Date; { Defined above }
2187: END;
2188: END;
2189:
2190: Note = Paragraphs - (Ref_note);
2191:
2192: UNITS { Elements which can be used in objects }
2193:
2194: Ref_note = REFERENCE (Note);
2195: Ref_biblio = REFERENCE (Biblio_citation);
2196: Ref_figure = REFERENCE (Figure);
2197: Ref_formula = REFERENCE (Isolated_formula);
2198:
2199: EXPORT { Skeleton elements }
2200:
2201: Title,
1.5 cvs 2202: Figure with Figure_caption,
1.1 cvs 2203: Section With Section_title;
2204:
1.18 cvs 2205: END { End of the structure schema }</pre>
1.30 cvs 2206:
2207: <p>This schema is very complete since it defines both paragraphs and
1.37 ! cvs 2208: bibliographic citations. These element types could just as well be defined in
! 2209: other structure schemas, as is the case with the <tt>Formula</tt> class. All
! 2210: sorts of other elements can be inserted into an article, since a paragraph
! 2211: can contain any type of unit. Similarly, figures can be any class of document
! 2212: or object that the user chooses.</p>
! 2213:
! 2214: <p>Generally, an article doesn't contain appendices, but it is possible to
! 2215: add them on explicit request: this is the effect of the question mark before
! 2216: the word Appendices.</p>
1.30 cvs 2217:
1.37 ! cvs 2218: <p>Various types of cross-references can be put in paragraphs. They can also
1.30 cvs 2219: be placed the objects which are part of the article, since the
2220: cross-references are defined as units (<tt>UNITS</tt>).</p>
2221:
2222: <p>There is a single restriction to prevent the creation of Ref_note elements
1.18 cvs 2223: within notes.</p>
1.30 cvs 2224:
2225: <p>It is worth noting that the S language permits the definition of recursive
1.37 ! cvs 2226: structures like sections: a section can contain other sections (which are
! 2227: thus at the next lower level of the document tree). Paragraphs are also
! 2228: recursive elements, since a paragraph can contain an enumeration in which
! 2229: each element (<tt>Item</tt>) is composed of paragraphs.</p>
1.18 cvs 2230: </div>
1.1 cvs 2231:
1.18 cvs 2232: <div class="subsection">
1.37 ! cvs 2233: <h3><a name="sectc332" id="sectc332">A class of objects: mathematical
! 2234: formulas</a></h3>
1.1 cvs 2235:
1.30 cvs 2236: <p>The example below defines the <tt>Formula</tt> class which is used in
1.37 ! cvs 2237: Article documents. This class represents mathematical formulas with a rather
1.30 cvs 2238: simple structure, but sufficient to produce a correct rendition on the screen
1.37 ! cvs 2239: or printer. To support more elaborate operations (formal or numeric
! 2240: calculations), a finer structure should be defined. This class doesn't use
! 2241: any other class and doesn't define any units.</p>
1.18 cvs 2242: <pre>STRUCTURE Formula;
1.1 cvs 2243: DEFPRES FormulaP;
2244:
2245: ATTR
2246: String_type = Function_name, Variable_name;
2247:
2248: STRUCT
2249: Formula = Expression;
2250: Expression = LIST OF (Construction);
2251: Construction = CASE OF
2252: TEXT; { Simple character string }
2253: Index = Expression;
2254: Exponent = Expression;
2255: Fraction =
2256: BEGIN
1.6 cvs 2257: Numerator = Expression;
1.1 cvs 2258: Denominator = Expression;
2259: END;
2260: Root =
2261: BEGIN
2262: ? Order = TEXT;
2263: Root_Contents = Expression;
2264: END;
2265: Integral =
2266: BEGIN
2267: Integration_Symbol = SYMBOL;
2268: Lower_Bound = Expression;
2269: Upper_Bound = Expression;
2270: END;
2271: Triple =
2272: BEGIN
2273: Princ_Expression = Expression;
2274: Lower_Expression = Expression;
2275: Upper_Expression = Expression;
2276: END;
2277: Column = LIST [2..*] OF
2278: (Element = Expression);
2279: Parentheses_Block =
2280: BEGIN
2281: Opening = SYMBOL;
2282: Contents = Expression;
2283: Closing = SYMBOL;
2284: END;
2285: END; { End of Choice Constructor }
1.18 cvs 2286: END { End of Structure Schema }</pre>
1.30 cvs 2287:
2288: <p>This schema defines a single global attribute which allows functions and
1.37 ! cvs 2289: variables to be distinguished. In the presentation schema, this attribute can
1.1 cvs 2290: be used to choose between roman (for functions) and italic characters (for
1.18 cvs 2291: variables).</p>
1.30 cvs 2292:
1.37 ! cvs 2293: <p>A formula's structure is that of a mathematical expression, which is
! 2294: itself a sequence of mathematical constructions. A mathematical construction
! 2295: can be either a simple character string, an index, an exponent, a fraction, a
! 2296: root, etc. Each of these mathematical constructions has a sensible structure
! 2297: which generally includes one or more expressions, thus making the formula
! 2298: class's structure definition recursive.</p>
1.30 cvs 2299:
2300: <p>In most cases, the roots which appear in the formulas are square roots and
1.37 ! cvs 2301: their order (2) is not specified. This is why the Order component is marked
! 2302: optional by a question mark. When explicitly requested, it is possible to add
1.18 cvs 2303: an order to a root, for example for cube roots (order = 3).</p>
1.30 cvs 2304:
2305: <p>An integral is formed by an integration symbol, chosen by the user (simple
1.37 ! cvs 2306: integral, double, curvilinear, etc.), and two bounds. A more fine-grained
1.1 cvs 2307: schema would add components for the integrand and the integration variable.
1.37 ! cvs 2308: Similarly, the Block_Parentheses construction leaves the choice of opening
! 2309: and closing symbols to the user. They can be brackets, braces, parentheses,
1.18 cvs 2310: etc.</p>
2311: </div>
2312: </div>
1.37 ! cvs 2313: <hr />
1.18 cvs 2314: </div>
1.1 cvs 2315:
1.18 cvs 2316: <div class="chapter">
1.37 ! cvs 2317: <h1><a name="sect4" id="sect4">The P Language</a></h1>
1.1 cvs 2318:
1.18 cvs 2319: <div class="section">
1.37 ! cvs 2320: <h2><a name="sectb41" id="sectb41">Document presentation</a></h2>
1.1 cvs 2321:
1.30 cvs 2322: <p>Because of the model adopted for Thot, the presentation of documents is
1.37 ! cvs 2323: clearly separated from their structure and content. After having presented
1.1 cvs 2324: the logical structure of documents, we now detail the principles implemented
1.37 ! cvs 2325: for their presentation. The concept of <em>presentation</em> encompasses what
! 2326: is often called the page layout, the composition, or the document style. It
1.18 cvs 2327: is the set of operations which display the document on the screen or print it
1.37 ! cvs 2328: on paper. Like logical structure, document presentation is defined
1.18 cvs 2329: generically with the help of a language, called P.</p>
1.1 cvs 2330:
1.18 cvs 2331: <div class="subsection">
1.37 ! cvs 2332: <h3><a name="sectc411" id="sectc411">Two levels of presentation</a></h3>
1.1 cvs 2333:
1.30 cvs 2334: <p>The link between structure and presentation is clear: the logical
2335: organization of a document is used to carry out its presentation, since the
2336: purpose of the presentation is to make evident the organization of the
1.37 ! cvs 2337: document. But the presentation is equally dependent on the device used to
1.30 cvs 2338: render the document. Certain presentation effects, notably changes of font or
1.37 ! cvs 2339: character set, cannot be performed on all printers or on all screens. This is
1.30 cvs 2340: why Thot uses a two-level approach, where the presentation is first described
2341: in abstract terms, without taking into account each particular device, and
2342: then the presentation is realized within the constraints of a given
2343: device.</p>
2344:
2345: <p>Thus, presentation is only described as a function of the structure of the
1.37 ! cvs 2346: documents and the image that would be produced on an idealized device. For
1.1 cvs 2347: this reason, presentation descriptions do not refer to any device
1.18 cvs 2348: characteristics: they describe <em>abstract presentations</em> which can be
2349: concretized on different devices.</p>
1.30 cvs 2350:
2351: <p>A presentation description also defines a <em>generic presentation</em>,
2352: since it describes the appearance of a class of documents or objects. This
2353: generic presentation must also be applied to document and object instances,
2354: each conforming to its generic logical structure, but with all the allowances
2355: that were called to mind above: missing elements, constructed elements with
2356: other logical structures, etc.</p>
2357:
2358: <p>In order to preserve the homogeneity between documents and objects,
1.1 cvs 2359: presentation is described with a single set of tools which support the layout
2360: of a large document as well as the composition of objects like a graphical
1.37 ! cvs 2361: figure or mathematical formula. This unity of presentation description tools
1.1 cvs 2362: contrasts with the traditional approach, which focuses more on documents than
2363: objects and thus is based on the usual typographic conventions, such as the
2364: placement of margins, indentations, vertical spaces, line lengths,
1.18 cvs 2365: justification, font changes, etc.</p>
2366: </div>
1.1 cvs 2367:
1.18 cvs 2368: <div class="subsection">
1.37 ! cvs 2369: <h3><a name="sectc412" id="sectc412">Boxes</a></h3>
1.1 cvs 2370:
1.37 ! cvs 2371: <p>To assure the homogeneity of tools, all presentation in Thot, for
! 2372: documents as well as for the objects which they contain, is based on the
! 2373: notion of the <em>box</em>, such as was implemented in
! 2374: T<sub><big>E</big></sub>X.</p>
1.30 cvs 2375:
1.37 ! cvs 2376: <p>Corresponding to each element of the document is a box, which is the
1.1 cvs 2377: rectangle enclosing the element on the display device (screen or sheet of
1.37 ! cvs 2378: paper); the outline of this rectangle is not visible, except when a <a
! 2379: href="#sectc4230a"><tt>ShowBox</tt> rule</a> applies to the element. The
! 2380: sides of the box are parallel to the sides of the screen or the sheet of
! 2381: paper. By way of example, a box is associated with a character string, a line
! 2382: of text, a page, a paragraph, a title, a mathematical formula, or a table
! 2383: cell.</p>
1.30 cvs 2384:
2385: <p>Whatever element it corresponds to, each box possesses four sides and four
1.18 cvs 2386: axes, which we designate as follows (<a href="#boxes">see figure</a>):</p>
2387: <dl>
1.30 cvs 2388: <dt><tt>Top</tt></dt>
2389: <dd>the upper side,</dd>
2390: <dt><tt>Bottom</tt></dt>
2391: <dd>the lower side,</dd>
2392: <dt><tt>Left</tt></dt>
2393: <dd>the left side,</dd>
2394: <dt><tt>Right</tt></dt>
2395: <dd>the right side,</dd>
2396: <dt><tt>VMiddle</tt></dt>
2397: <dd>the vertical axis passing through the center of the box,</dd>
2398: <dt><tt>HMiddle</tt></dt>
2399: <dd>the horizontal axis passing through the center of the box,</dd>
2400: <dt><tt>VRef</tt></dt>
2401: <dd>the vertical reference axis,</dd>
2402: <dt><tt>HRef</tt></dt>
2403: <dd>the horizontal reference axis.</dd>
1.18 cvs 2404: </dl>
2405:
2406: <div class="figure">
1.37 ! cvs 2407: <hr />
1.18 cvs 2408: <pre> Left VRef VMiddle Right
1.1 cvs 2409: : :
2410: Top -----------------------------
2411: | : : |
2412: | : : |
2413: | : : |
2414: | : : |
2415: | : : |
2416: HMiddle ..|...........................|..
2417: | : : |
2418: | : : |
2419: HRef ..|...........................|..
2420: | : : |
2421: | : : |
2422: Bottom -----------------------------
1.18 cvs 2423: : :</pre>
1.30 cvs 2424:
1.37 ! cvs 2425: <p align="center"><em><a name="boxes" id="boxes">The sides and axes of
1.30 cvs 2426: boxes</a><em></em></em></p>
1.37 ! cvs 2427: <hr />
1.30 cvs 2428: </div>
1.19 cvs 2429:
1.37 ! cvs 2430: <p>The principal role of boxes is to set the extent and position of the
! 2431: images of the different elements of a document with respect to each other on
! 2432: the reproduction device. This is done by defining relations between the boxes
! 2433: of different elements which give relative extents and positions to these
1.18 cvs 2434: boxes.</p>
1.30 cvs 2435:
2436: <p>There are three types of boxes:</p>
1.18 cvs 2437: <ul>
1.30 cvs 2438: <li>boxes corresponding to structural elements of the document,</li>
2439: <li>presentation boxes,</li>
2440: <li>page layout boxes.</li>
1.18 cvs 2441: </ul>
1.30 cvs 2442:
1.37 ! cvs 2443: <p><strong>Boxes corresponding to structural elements of the
! 2444: document</strong> are those which linked to each of the elements (base or
! 2445: structured) of the logical structure of the document. Such a box contains all
! 2446: the contents of the element to which it corresponds (there is an exception:
! 2447: see <a href="#sectc4220">rules <tt>VertOverflow</tt> and
! 2448: <tt>HorizOverflow</tt></a>). These boxes form a tree-like structure,
! 2449: identical to that of the structural elements to which they correspond. This
! 2450: tree expresses the inclusion relationships between the boxes: a box includes
! 2451: all the boxes of its subtree. On the other hand, there are no predefined
! 2452: rules for the relative positions of the included boxes. If they are at the
! 2453: same level, they can overlap, be contiguous, or be disjoint. The rules
! 2454: expressed in the generic presentation specify their relative positions.</p>
1.30 cvs 2455:
2456: <p><strong>Presentation boxes</strong> represent elements which are not found
1.37 ! cvs 2457: in the logical structure of the document but which are added to meet the
! 2458: needs of presentation. These boxes are linked to the elements of the logical
1.30 cvs 2459: structure that are best suited to bringing them out. For example, they are
2460: used to add the character string ``Summary:'' before the summary in the
2461: presentation of a report or to represent the fraction bar in a formula, or
1.37 ! cvs 2462: also to make the title of a field in a form appear. These elements have no
1.30 cvs 2463: role in the logical structure of the document: the presence of a Summary
2464: element in the document does not require the creation of another structural
1.37 ! cvs 2465: object to hold the word ``Summary''. Similarly, if a Fraction element
! 2466: contains both a Numerator element and a Denominator element, the fraction bar
! 2467: has no purpose structurally. On the other hand, these elements of the
! 2468: presentation are important for the reader of the reproduced document or for
! 2469: the user of an editor. This is why they must appear in the document's image.
! 2470: It is the generic presentation which specifies the presentation boxes to add
! 2471: by indicating their content (a base element for which the value is specified)
! 2472: and the position that they must take in the tree of boxes. During editing,
! 2473: these boxes cannot be modified by the user.</p>
! 2474:
! 2475: <p><strong>Page layout boxes</strong> are boxes created implicitly by the
! 2476: page layout rules. These rules indicate how the contents of a structured
! 2477: element must be broken into lines and pages. In contrast to presentation
! 2478: boxes, these line and page boxes do not depend on the logical structure of
! 2479: the document, but rather on the physical constraints of the output devices:
! 2480: character size, height and width of the window on the screen or of the sheet
! 2481: of paper.</p>
1.18 cvs 2482: </div>
1.1 cvs 2483:
1.18 cvs 2484: <div class="subsection">
1.37 ! cvs 2485: <h3><a name="sectc413" id="sectc413">Views and visibility</a></h3>
1.1 cvs 2486:
1.30 cvs 2487: <p>One of the operations that one might wish to perform on a document is to
1.37 ! cvs 2488: view it is different ways. For this reason, it is possible to define several
1.18 cvs 2489: <em>views</em> for the same document, or better yet, for all documents of the
1.37 ! cvs 2490: same class. A view is not a different presentation of the document, but
1.1 cvs 2491: rather a filter which only allows the display of certain parts of the
1.37 ! cvs 2492: document. For example, it might be desirable to see only the titles of
1.1 cvs 2493: chapters and sections in order to be able to move rapidly through the
1.37 ! cvs 2494: document. Such a view could be called a ``table of contents''. It might also
1.1 cvs 2495: be desirable to see only the mathematical formulas of a document in order to
1.37 ! cvs 2496: avoid being distracted by the non-mathematical aspects of the document. A
1.18 cvs 2497: ``mathematics'' view could provide this service.</p>
1.30 cvs 2498:
2499: <p>Views, like presentation, are based on the generic logical structure. Each
1.1 cvs 2500: document class, and each generic presentation, can be provided with views
1.37 ! cvs 2501: which are particularly useful for that class or presentation. For each view,
1.18 cvs 2502: the <em>visibility</em> of elements is defined, indicated whether or not the
1.37 ! cvs 2503: elements must be presented to the user. The visibility is calculated as a
1.1 cvs 2504: function of the type of the elements or their hierarchical position in the
1.37 ! cvs 2505: structure of the document. Thus, for a table of contents, all the ``Chapter
! 2506: Title'' and ``Section Title'' elements are made visible. However, the
1.1 cvs 2507: hierarchical level could be used to make the section titles invisible below a
1.37 ! cvs 2508: certain threshold level. By varying this threshold, the granularity of the
! 2509: view can be varied. In the ``mathematics'' view, only Formula elements would
1.18 cvs 2510: be made visible, no matter what their hierarchical level.</p>
1.30 cvs 2511:
2512: <p>Because views are especially useful for producing a synthetic image of the
1.1 cvs 2513: document, it is necessary to adapt the presentation of the elements to the
1.37 ! cvs 2514: view in which they appear. For example, it is inappropriate to have a page
! 2515: break before every chapter title in the table of contents. Thus, generic
1.1 cvs 2516: presentations take into account the possible views and permit each element
1.18 cvs 2517: type's presentation to vary according the view in which its image appears.</p>
2518: </div>
1.1 cvs 2519:
1.18 cvs 2520: <div class="subsection">
1.37 ! cvs 2521: <h3><a name="sectc414" id="sectc414">Pages</a></h3>
1.1 cvs 2522:
1.30 cvs 2523: <p>Presentation schemas can be defined which display the document as a long
1.37 ! cvs 2524: scroll, without page breaks. This type of schema is particularly well-suited
1.1 cvs 2525: to the initial phase of work on a document, where jumps from page to page
1.37 ! cvs 2526: would hinder composing and reading the document on a screen. But, once the
! 2527: document is written, it may be desirable to display the document on the
! 2528: screen in the same manner in which it will be printed. So, the presentation
! 2529: schema must define pages.</p>
! 2530:
! 2531: <p>The P language permits the specification of the dimensions of pages as
! 2532: well as their composition. It is possible to generate running titles, page
! 2533: numbers, zones at the bottom of the page for notes, etc. The editor follows
1.30 cvs 2534: this model and inserts page break marks in the document which are used during
2535: printing, insuring that the pages on paper are the same as on the screen.</p>
2536:
2537: <p>Once a document has been edited with a presentation schema defining pages,
1.37 ! cvs 2538: it contains page marks. But it is always possible to edit the document using
! 2539: a schema without pages. In this case, the page marks are simply ignored by
! 2540: the editor. They are considered again as soon as a schema with pages is used.
1.18 cvs 2541: Thus, the user is free to choose between schemas with and without pages.</p>
1.30 cvs 2542:
2543: <p>Thot treats the page break, rather than the page itself, as a box. This
2544: page break box contains all the elements of one page's footer, a rule marking
1.37 ! cvs 2545: the edge of this page, and all the elements of the next page's header. The
! 2546: elements of the header and footer can be running titles, page number, notes,
! 2547: etc. All these elements, as well as their content and graphical appearance,
! 2548: are defined by the generic presentation.</p>
1.18 cvs 2549: </div>
1.1 cvs 2550:
1.18 cvs 2551: <div class="subsection">
1.37 ! cvs 2552: <h3><a name="sectc415" id="sectc415">Numbering</a></h3>
1.1 cvs 2553:
1.30 cvs 2554: <p>Many elements are numbered in documents: pages, chapters, sections,
2555: formulas, theorems, notes, figures, bibliographic references, exercises,
1.37 ! cvs 2556: examples, lemmas, etc. Because Thot has a notion of logical structure, all of
1.30 cvs 2557: these numbers (with the exception of pages) are redundant with information
1.37 ! cvs 2558: implicit in the logical structure of the document. Such numbers are simply a
! 2559: way to make the structure of the document more visible. So, they are part of
1.30 cvs 2560: the document's presentation and are calculated by the editor from the logical
1.37 ! cvs 2561: structure. The structure does not contain numbers as such; it only defines
1.1 cvs 2562: relative structural positions between elements, which serve as ordering
1.18 cvs 2563: relations on these elements.</p>
1.30 cvs 2564:
2565: <p>If the structure schema defines the body of a document as a sequence of at
1.18 cvs 2566: least two chapters:</p>
2567: <pre>Body = LIST [2..*] OF Chapter;</pre>
1.30 cvs 2568:
2569: <p>the sequence defined by the list constructor is ordered and each chapter
1.37 ! cvs 2570: can be assigned a number based on its rank in the Body list. Therefore, all
! 2571: elements contained in lists a the structure of a document can be numbered,
! 2572: but they are not the only ones. The tree structure induced by the aggregate,
1.18 cvs 2573: list, and choice constructors (excluding references) defines a total order on
1.37 ! cvs 2574: the elements of the document's primary structure. So, it is possible to
1.18 cvs 2575: define a numbering which uses this order, filtering elements according to
2576: their type so that only certain element types are taken into account in the
1.37 ! cvs 2577: numbering. In this way, it possible to number all the theorems and lemmas of
1.18 cvs 2578: a chapter in the same sequence of numbers, even when they are not part of the
2579: same list constructor and appear at different levels of the document's tree.
2580: By changing the filter, they can be numbered separately: one sequence of
2581: numbers for theorems, another for the lemmas.</p>
1.30 cvs 2582:
2583: <p>Since they are calculated from the document's logical structure and only
2584: for the needs of the presentation, numbers are presentation elements,
2585: described by presentation boxes, just like the fraction bar or the word
1.37 ! cvs 2586: ``Summary''. Nevertheless, numbers differ from these other boxes because
! 2587: their content varies from instance to instance, even though they are of the
! 2588: same type, whereas all fraction bars are horizontal lines and the same word
1.30 cvs 2589: ``Summary'' appears at the head of every document's summary.</p>
1.18 cvs 2590: </div>
1.1 cvs 2591:
1.18 cvs 2592: <div class="subsection">
1.37 ! cvs 2593: <h3><a name="sectc416" id="sectc416">Presentation properties</a></h3>
1.1 cvs 2594:
1.34 cvs 2595: <p>The principal properties which determine document presentation are the
1.18 cvs 2596: <em>positions</em> and <em>dimensions</em> of boxes, the <em>font</em>, the
2597: <em>style</em>, the <em>size</em>, the <em>underlining</em> and the
1.37 ! cvs 2598: <em>color</em> of their content. From these properties, and some others of
1.34 cvs 2599: less importance, it is possible to represent the usual typographic properties
1.37 ! cvs 2600: for the textual parts of the document. These same properties can be used to
1.1 cvs 2601: describe the geometry of the non-textual elements, even though they are
1.18 cvs 2602: two-dimensional elements unlike the text, which is linear.</p>
1.30 cvs 2603:
1.37 ! cvs 2604: <p>As we have already seen, the positions of the boxes always respect the
1.30 cvs 2605: rule of enclosure: a box in the tree encloses all the boxes of the next lower
1.37 ! cvs 2606: level which are attached to it. The positional properties permit the
1.30 cvs 2607: specification of the position of each box in relation to the enclosing box or
1.37 ! cvs 2608: to its sibling boxes (boxes directly attached to the same enclosing box in
! 2609: the tree of boxes).</p>
1.30 cvs 2610:
1.37 ! cvs 2611: <p>The presentation properties also provide control over the dimensions of
! 2612: the boxes. The dimensions of a box can depend either on its content or on its
1.1 cvs 2613: context (its sibling boxes and the enclosing box). Each dimension (height or
1.18 cvs 2614: width) can be defined independently of the other.</p>
1.30 cvs 2615:
1.34 cvs 2616: <p>Because of the position and dimension properties, it is possible to do the
1.1 cvs 2617: same things that are normally done in typography by changing margins, line
1.37 ! cvs 2618: lengths, and vertical or horizontal skips. This approach can also align or
1.18 cvs 2619: center elements and groups of elements.</p>
1.30 cvs 2620:
1.34 cvs 2621: <p>In contrast to the position and dimension properties, the font, style,
1.30 cvs 2622: size, underlining, and color do not concern the box itself (the rectangle
1.37 ! cvs 2623: delimiting the element), but its content. These properties indicate the
! 2624: typographic attributes which must be applied to the text contained in the
! 2625: box, and by extension, to all base elements.</p>
1.30 cvs 2626:
1.34 cvs 2627: <p>For text, the font property is used to change the family of characters
1.1 cvs 2628: (Times, Helvetica, Courier, etc.); the style is used to obtain italic or
1.37 ! cvs 2629: roman, bold or light characters; the size determines the point size of the
1.1 cvs 2630: characters; underlining defines the type and thickness of the lines drawn
1.18 cvs 2631: above, below, or through the characters.</p>
1.30 cvs 2632:
1.34 cvs 2633: <p>For graphics, the line style property can be either solid, dotted, or
2634: dashed; the line thickness property controls the width of the lines; the fill
2635: pattern property determines how closed geometric figures must be filled.</p>
1.30 cvs 2636:
1.34 cvs 2637: <p>While some of the properties which determine the appearance of a box's
1.1 cvs 2638: contents make sense only for one content type (text or graphic), other
1.34 cvs 2639: properties apply to all content types: these are the color properties. These
1.18 cvs 2640: indicate the color of lines and the background color.</p>
2641: </div>
2642: </div>
1.1 cvs 2643:
1.18 cvs 2644: <div class="section">
1.37 ! cvs 2645: <h2><a name="sectb42" id="sectb42">Presentation description language</a></h2>
1.30 cvs 2646:
1.34 cvs 2647: <p>A generic presentation defines the values of presentation properties (or
1.37 ! cvs 2648: the way to calculate those values) for a generic structure, or more
! 2649: precisely, for all the element types and all the global and local attributes
! 2650: defined in that generic structure. This definition of the presentation
! 2651: properties is made with the P language. A program written in this language,
! 2652: that is a generic presentation expressed in P, is call a <em>presentation
! 2653: schema</em>. This section describes the syntax and semantics of the language,
! 2654: using the same <a href="#sectc321">meta-language</a> as was used for the
! 2655: definition of the S language.</p>
! 2656:
! 2657: <p>Recall that it is possible to write many different presentation schemas
! 2658: for the same class of documents or objects. This allows users to choose for a
! 2659: document the graphical appearance which best suits their type of work or
1.18 cvs 2660: their personal taste.</p>
1.1 cvs 2661:
1.18 cvs 2662: <div class="subsection">
1.37 ! cvs 2663: <h3><a name="sectc421" id="sectc421">The organization of a presentation
! 2664: schema</a></h3>
1.1 cvs 2665:
1.30 cvs 2666: <p>A presentation schema begins with the word <tt>PRESENTATION</tt> and ends
1.37 ! cvs 2667: with the word <tt>END</tt>. The word <tt>PRESENTATION</tt> is followed by the
! 2668: name of the generic structure to which the presentation will be applied. This
1.30 cvs 2669: name must be the same as that which follows the keyword <tt>STRUCTURE</tt> in
2670: the structure schema associated with the presentation schema.</p>
2671:
1.37 ! cvs 2672: <p>After this declaration of the name of the structure, the following
! 2673: sections appear (in order):</p>
1.18 cvs 2674: <ul>
1.37 ! cvs 2675: <li>Declarations of
1.30 cvs 2676: <ul>
2677: <li>all views,</li>
2678: <li>printed views,</li>
2679: <li>counters,</li>
2680: <li>presentation constants,</li>
2681: <li>variables,</li>
2682: </ul>
2683: </li>
2684: <li>default presentation rules,</li>
2685: <li>presentation box and page layout box definitions,</li>
2686: <li>presentation rules for structured elements,</li>
2687: <li>presentation rules for attributes,</li>
2688: <li>rules for transmitting values to attributes of included documents.</li>
1.18 cvs 2689: </ul>
1.30 cvs 2690:
2691: <p>Each of these sections is introduced by a keyword which is followed by a
1.37 ! cvs 2692: sequence of declarations. Every section is optional.</p>
1.18 cvs 2693: <pre> SchemaPres ='PRESENTATION' ElemID ';'
1.1 cvs 2694: [ 'VIEWS' ViewSeq ]
2695: [ 'PRINT' PrintViewSeq ]
2696: [ 'COUNTERS' CounterSeq ]
2697: [ 'CONST' ConstSeq ]
2698: [ 'VAR' VarSeq ]
2699: [ 'DEFAULT' ViewRuleSeq ]
2700: [ 'BOXES' BoxSeq ]
2701: [ 'RULES' PresentSeq ]
2702: [ 'ATTRIBUTES' PresAttrSeq ]
2703: [ 'TRANSMIT' TransmitSeq ]
2704: 'END' .
1.18 cvs 2705: ElemID = NAME .</pre>
2706: </div>
1.1 cvs 2707:
1.18 cvs 2708: <div class="subsection">
1.37 ! cvs 2709: <h3><a name="sectc422" id="sectc422">Views</a></h3>
1.1 cvs 2710:
1.37 ! cvs 2711: <p>Each of the possible views must be declared in the presentation schema. As
! 2712: has <a href="#views">already been described</a>, the presentation rules for
! 2713: an element type can vary according to the view in which the element appears.
! 2714: The name of the view is used to designate the view to which the presentation
! 2715: rules apply (see the <a href="#inkeyword"><tt>IN</tt> instruction</a>). The
1.1 cvs 2716: definition of the view's contents are dispersed throughout the presentation
1.37 ! cvs 2717: rules attached to the different element types and attributes. The
1.18 cvs 2718: <tt>VIEWS</tt> section is simply a sequence of view names separated by commas
2719: and terminated by a semi-colon.</p>
1.30 cvs 2720:
2721: <p>One of the view names (and only one) can be followed by the keyword
1.37 ! cvs 2722: <tt>EXPORT</tt>. This keyword identifies the view which presents the members
! 2723: of the document class in <a href="#sectc3213">skeleton form</a>. The
! 2724: graphical appearance and the content of this view is defined just as with
1.18 cvs 2725: other views, but it is useless to specify presentation rules concerning this
2726: view for the elements which are not loaded in the skeleton form.</p>
1.30 cvs 2727:
2728: <p>It is not necessary to declare any views; in this case there is a single
1.37 ! cvs 2729: unnamed view. If many views are declared, the first view listed is considered
! 2730: the principal view. The principal view is the one to which all rules that are
1.18 cvs 2731: not preceded by an indication of a view will apply (see the <a
2732: href="#inkeyword">instruction <tt>IN</tt></a>).</p>
1.30 cvs 2733:
2734: <p>The principal view is the the one which the editor presents on the screen
1.37 ! cvs 2735: when the user asks to create or edit a document. Thus, it makes sense to put
! 2736: the most frequently used view at the head of the list. But if the structure
1.18 cvs 2737: schema contains <a href="#sectc3213">skeleton elements</a> and is loaded in
2738: its skeleton form, the view whose name is followed by the keyword
2739: <tt>EXPORT</tt> will be opened and no other views can be opened.</p>
2740: <pre> 'VIEWS' ViewSeq
1.1 cvs 2741: ViewSeq = ViewDeclaration
1.30 cvs 2742: < ',' ViewDeclaration > ';' .
1.1 cvs 2743: ViewDeclaration = ViewID [ 'EXPORT' ] .
1.18 cvs 2744: ViewID = NAME .</pre>
1.30 cvs 2745:
1.18 cvs 2746: <blockquote class="example">
1.30 cvs 2747: <p><strong>Example:</strong></p>
2748:
2749: <p>When editing a report, it might be useful have views of the table of
1.37 ! cvs 2750: contents and of the mathematical formulas, in addition to the principal
! 2751: view which shows the document in its entirety. To achieve this, a
! 2752: presentation schema for the Report class would have the following
! 2753: <tt>VIEWS</tt> section:</p>
1.30 cvs 2754: <pre>VIEWS
1.18 cvs 2755: Full_text, Table_of_contents, Formulas;</pre>
1.30 cvs 2756:
2757: <p>The contents of these views are specified in the presentation rules of
2758: the schema.</p>
1.18 cvs 2759: </blockquote>
2760: </div>
1.1 cvs 2761:
1.18 cvs 2762: <div class="subsection">
1.37 ! cvs 2763: <h3><a name="sectc423" id="sectc423">Print Views</a></h3>
1.1 cvs 2764:
1.37 ! cvs 2765: <p>When editing a document, each view specified by the <tt>VIEWS</tt>
! 2766: instruction is presented in a different window.</p>
1.30 cvs 2767:
2768: <p>When printing a document, it is possible to print any number of views,
1.37 ! cvs 2769: chosen from among all the views which the editor can display. Print views, as
! 2770: well as the order in which they must be printed, are indicated by the
! 2771: <tt>PRINT</tt> instruction. It appears after the <tt>VIEWS</tt> instruction
! 2772: and is formed of the keyword <tt>PRINT</tt> followed by the ordered list of
! 2773: print view names. The print view names are separated by commas and followed
! 2774: by a semi-colon. A print view name is a view name declared in the
! 2775: <tt>VIEWS</tt> instruction.</p>
1.18 cvs 2776: <pre> 'PRINT' PrintViewSeq
1.30 cvs 2777: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.37 ! cvs 2778: PrintView = ViewID .</pre>
1.30 cvs 2779:
2780: <p>If the <tt>PRINT</tt> instruction is absent, the printing program will
2781: print only the principal view (the first view specified by the <tt>VIEWS</tt>
1.18 cvs 2782: instruction or the single, unnamed view when there is no <tt>VIEWS</tt>
2783: instruction).</p>
1.30 cvs 2784:
1.18 cvs 2785: <blockquote class="example">
1.30 cvs 2786: <p><strong>Example:</strong></p>
2787:
2788: <p>Consider a Report presentation using the view declarations from the
1.37 ! cvs 2789: preceding example. Suppose we want to print the full text and table of
1.30 cvs 2790: contents views, but not the Formulas view, which is only useful when
1.37 ! cvs 2791: editing. A sensible printing order would be to print the full text followed
! 2792: by the table of contents. To obtain this result when printing, the
! 2793: presentation schema would say:</p>
1.30 cvs 2794: <pre>PRINT
1.37 ! cvs 2795: Full_text, Table_of_contents;</pre>
1.18 cvs 2796: </blockquote>
2797: </div>
2798:
2799: <div class="subsection">
1.37 ! cvs 2800: <h3><a name="sectc424" id="sectc424">Counters</a></h3>
1.18 cvs 2801:
1.30 cvs 2802: <p>A presentation has a <em>counter</em> for each type of number in the
1.37 ! cvs 2803: presentation. All counters, and therefore all types of numbers, used in the
1.18 cvs 2804: schema must be declared after the <tt>COUNTERS</tt> keyword.</p>
1.30 cvs 2805:
2806: <p>Each counter declaration is composed of a name identifying the counter
1.1 cvs 2807: followed by a colon and the counting function to be applied to the counter.
1.18 cvs 2808: The counter declaration ends with a semi-colon.</p>
1.30 cvs 2809:
2810: <p>The counting function indicates how the counter values will be calculated.
1.37 ! cvs 2811: Three types of counting functions are available. The first type is used to
1.16 cvs 2812: count the elements of a list or aggregate: it assigns to the counter the rank
1.37 ! cvs 2813: of the element in the list or aggregate. More precisely, the function</p>
1.18 cvs 2814: <pre>RANK OF ElemID [ LevelAsc ] [ INIT AttrID ]
2815: [ 'REINIT' AttrID ]</pre>
1.30 cvs 2816:
2817: <p>indicates that when an element creates, by a creation rule (see the <a
1.18 cvs 2818: href="#sectc4232"><tt>Create</tt> instructions</a>), a presentation box
1.37 ! cvs 2819: containing the counter value, this value is the rank of the creating element,
1.18 cvs 2820: if it is of type <tt>ElemID</tt>, otherwise the rank of the first element of
2821: type <tt>ElemID</tt> which encloses the creating element in the logical
2822: structure of the document.</p>
1.30 cvs 2823:
2824: <p>The type name can be preceded by a star in the special case where the
1.18 cvs 2825: structure schema defines an element of whose <tt>ElemID</tt> is the same as
2826: that of an <a href="#sectd3284">inclusion</a> without expansion or with
1.37 ! cvs 2827: partial expansion. To resolve this ambiguity, the <tt>ElemID</tt> alone
1.18 cvs 2828: refers to the type defined in the structure schema while the <tt>ElemID</tt>
2829: preceded by a star refers to the included type.</p>
1.30 cvs 2830:
1.37 ! cvs 2831: <p>The type name <tt>ElemID</tt> can be followed by an integer. That number
! 2832: represents the relative level, among the ancestors of the creating element,
! 2833: of the element whose rank is asked. If that relative level <i>n</i> is
! 2834: unsigned, the <i>n</i><sup>th</sup> element of type <tt>ElemID</tt>
! 2835: encountered when travelling the logical structure from the root to the
! 2836: creating element is taken into account. If the relative level is negative,
! 2837: the logical structure is travelled in the other direction, from the creating
! 2838: element to the root.</p>
1.30 cvs 2839:
1.37 ! cvs 2840: <p>The function can end with the keyword <tt>INIT</tt> followed by the name
! 2841: of a numeric attribute (and only a numeric attribute). Then, the rank of the
1.30 cvs 2842: first element of the list or aggregate is considered to be the value of this
1.1 cvs 2843: attribute, rather than the default value of 1, and the rank of the other
1.37 ! cvs 2844: elements is shifted accordingly. The attribute which determines the initial
1.18 cvs 2845: value is searched on the element itself and on its ancestors.</p>
1.30 cvs 2846:
2847: <p>The function can end with the keyword <tt>REINIT</tt> followed by the name
1.37 ! cvs 2848: of a numeric attribute (and only a numeric attribute). Then, if an element to
1.30 cvs 2849: be counted has this attribute, the counter value for this element is the
1.1 cvs 2850: attribute value and the following elements are numbered starting from this
1.18 cvs 2851: value.</p>
1.30 cvs 2852:
2853: <p>When the <tt>RANK</tt> function is written</p>
1.18 cvs 2854: <pre>RANK OF Page [ ViewID ] [ INIT AttrID ]</pre>
1.30 cvs 2855:
2856: <p>(<tt>Page</tt>is a keyword of the P language), the counter takes as its
2857: value the number of the page on which the element which creates the
1.37 ! cvs 2858: presentation box containing the number appears. This is done as if the pages
! 2859: of the document form a list for each view. The counter only takes into
1.30 cvs 2860: account the pages of the relevant view, that is the view displaying the
1.37 ! cvs 2861: presentation box whose contents take the value of the number. However, if the
! 2862: keyword <tt>Page</tt> is followed by the name of a view (between
! 2863: parentheses), it is the pages of that view that are taken into account. As in
! 2864: the preceding form, the <tt>RANK</tt> function applied to pages can end with
! 2865: the <tt>INIT</tt> keyword followed by the name of a numeric attribute which
! 2866: sets the value of the first page's number. This attribute must be a local
1.30 cvs 2867: attribute of the document itself, and not of one of its components.</p>
2868:
2869: <p>The second counting function is used to count the occurrences of a certain
1.37 ! cvs 2870: element type in a specified context. The instruction</p>
1.18 cvs 2871: <pre>SET n ON Type1 ADD m ON Type2 [ INIT AttrID ]</pre>
1.30 cvs 2872:
2873: <p>says that when the document is traversed from beginning to end (in the
2874: order induced by the logical structure), the counter is assigned the value
1.18 cvs 2875: <tt>n</tt> each time an element of type <tt>Type1</tt> is encountered, no
2876: matter what the current value of the counter, and the value <tt>m</tt> is
2877: added to the current value of the counter each time an element of type
2878: <tt>Type2</tt> is encountered.</p>
1.30 cvs 2879:
2880: <p>As with the <tt>RANK</tt> function, the type names can be preceded by a
2881: star to resolve the ambiguity of included elements.</p>
2882:
1.37 ! cvs 2883: <p>If the function ends with the keyword <tt>INIT</tt> followed by the name
! 2884: of an attribute and if the document possesses this attribute, the value of
! 2885: this attribute is used in place of <tt>n</tt>. The attribute must be numeric.
! 2886: It is searched on the element itself and on its ancestors.</p>
1.30 cvs 2887:
2888: <p>This function can also be used with the <tt>Page</tt> keyword in the place
1.37 ! cvs 2889: of <tt>Type1</tt> or <tt>Type2</tt>. In the first case, the counter is
1.18 cvs 2890: reinitialized on each page with the value <tt>n</tt>, while in the second
1.37 ! cvs 2891: case, it is incremented by <tt>m</tt> on each page. As with the preceding
1.18 cvs 2892: counting function, the word <tt>Page</tt> can be followed by a name between
1.37 ! cvs 2893: parentheses. In this case, the name specifies a view whose pages are taken
1.18 cvs 2894: into account.</p>
1.30 cvs 2895:
2896: <p>The definition of a counter can contain several <tt>SET</tt> functions and
1.37 ! cvs 2897: several <tt>ADD</tt> functions, each with a different value. The total number
1.18 cvs 2898: of counting functions must not be greater than 6.</p>
1.30 cvs 2899:
1.37 ! cvs 2900: <p>The third counting function is used to count the elements of a certain
! 2901: type encountered when travelling from the creating element to the root of the
! 2902: logical structure. The creating element is included if it is of that type.
1.18 cvs 2903: That function is written</p>
2904: <pre>RLEVEL OF Type</pre>
1.30 cvs 2905:
2906: <p>where <tt>Type</tt> represents the type of the elements to be counted.</p>
2907:
2908: <p>The formal definition of counter declarations is:</p>
1.18 cvs 2909: <pre> 'COUNTERS' CounterSeq
1.30 cvs 2910: CounterSeq = Counter < Counter > .
1.1 cvs 2911: Counter = CounterID ':' CounterFunc ';' .
2912: CounterID = NAME .
2913: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
1.16 cvs 2914: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.30 cvs 2915: SetFunction < SetFunction >
2916: AddFunction < AddFunction >
1.16 cvs 2917: [ 'INIT' AttrID ] /
2918: 'RLEVEL' 'OF' ElemID .
1.1 cvs 2919: SLevelAsc = [ '-' ] LevelAsc .
2920: LevelAsc = NUMBER .
2921: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
2922: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
2923: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 2924: [ '*' ] ElemID .
1.18 cvs 2925: CounterValue = NUMBER .</pre>
1.30 cvs 2926:
1.18 cvs 2927: <blockquote class="example">
1.30 cvs 2928: <p><strong>Example:</strong></p>
2929:
2930: <p>If the body of a chapter is defined as a sequence of sections in the
2931: structure schema:</p>
2932: <pre>Chapter_body = LIST OF (Section =
1.1 cvs 2933: BEGIN
2934: Section_Title = Text;
2935: Section_Body = Paragraphs;
2936: END
1.18 cvs 2937: );</pre>
1.30 cvs 2938:
2939: <p>the section counter is declared:</p>
2940: <pre>SectionCtr : RANK OF Section;</pre>
2941:
2942: <p>and the display of the section number before the section title is
2943: obtained by a <a href="#sectc4232"><tt>CreateBefore</tt> rule</a> attached
2944: the <tt>Section_Title</tt> type, which creates a presentation box whose
2945: content is the value of the <tt>SectionCtr</tt> counter (see the <a
2946: href="#sectc4231"><tt>Content</tt> instruction</a>).</p>
2947:
2948: <p>In order to number the formulas separately within each chapter, the
2949: formula counter is declared:</p>
2950: <pre>FormulaCtr : SET 0 ON Chapter ADD 1 ON Formula;</pre>
2951:
1.37 ! cvs 2952: <p>and the display of the formula number in the right margin, alongside
! 2953: each formula, is obtained by a <tt>CreateAfter</tt> instruction attached to
! 2954: the <tt>Formula</tt> type, which creates a presentation box whose content
! 2955: is the value of the <tt>FormulaCtr</tt> counter.</p>
1.30 cvs 2956:
2957: <p>To number the page chapter by chapter, with the first page of each
2958: chapter having the number 1, the counter definition would be</p>
2959: <pre>ChapterPageCtr : SET 0 ON Chapter ADD 1 ON Page;</pre>
2960:
2961: <p>If there is also a chapter counter</p>
2962: <pre>ChapterCtr : RANK OF Chapter;</pre>
2963:
1.37 ! cvs 2964: <p>the <a href="#sectc4231">content</a> of a presentation box created at
! 2965: the top of each page could be defined as:</p>
1.30 cvs 2966: <pre>Content : (VALUE(ChapterCtr, URoman) TEXT '-'
1.18 cvs 2967: VALUE(ChapterPageCtr, Arabic));</pre>
1.30 cvs 2968:
2969: <p>Thus, the presentation box contains the number of the chapter in
2970: upper-case roman numerals followed by a hyphen and the number of the page
2971: within the chapter in arabic numerals.</p>
1.18 cvs 2972: </blockquote>
1.30 cvs 2973:
1.18 cvs 2974: <blockquote class="example">
1.30 cvs 2975: <p><strong>Example:</strong></p>
2976:
1.37 ! cvs 2977: <p>To count tables and figures together in a document of the chapter type,
! 2978: a counter could be defined using:</p>
1.30 cvs 2979: <pre>CommonCtr : SET 0 ON Chapter ADD 1 ON Table
1.18 cvs 2980: ADD 1 ON Figure;</pre>
2981: </blockquote>
2982: </div>
1.1 cvs 2983:
1.18 cvs 2984: <div class="subsection">
1.37 ! cvs 2985: <h3><a name="sectc425" id="sectc425">Presentation constants</a></h3>
1.1 cvs 2986:
1.30 cvs 2987: <p>Presentation constants are used in the definition of the content of
1.37 ! cvs 2988: presentation boxes. This content is used in <a href="#sectc426">variable
! 2989: definitions</a> and in the <a href="#sectc4231"><tt>Content</tt> rule</a>.
! 2990: The only presentation constants which can be used are character strings,
1.2 cvs 2991: mathematical symbols, graphical elements, and pictures, that is to say, base
1.18 cvs 2992: elements.</p>
1.30 cvs 2993:
2994: <p>Constants can be defined directly in the variables or presentation boxes
1.37 ! cvs 2995: (<tt>Content</tt> rule) which use them. But it is only necessary them to
1.1 cvs 2996: declare once, in the constant declaration section, even though they are used
1.37 ! cvs 2997: in many variables or boxes. Thus, each declared constant has a name, which
1.1 cvs 2998: allows it to be designated whenever it is used, a type (one of the four base
2999: types) and a value (a character string or a single character for mathematical
1.18 cvs 3000: symbols and graphical elements).</p>
1.30 cvs 3001:
1.37 ! cvs 3002: <p>The constant declarations appear after the keyword <tt>CONST</tt>. Each
! 3003: declaration is composed of the name of the constant, an equals sign, a
! 3004: keyword representing its type (<tt>Text</tt>, <tt>Symbol</tt>,
! 3005: <tt>Graphics</tt> or <tt>Picture</tt>) and the string representing its value.
! 3006: A semi-colon terminates each declaration.</p>
1.30 cvs 3007:
3008: <p>In the case of a character string, the keyword <tt>Text</tt> can be
3009: followed by the name of an alphabet (for example, <tt>Greek</tt> or
1.37 ! cvs 3010: <tt>Latin</tt>) in which the constant's text should be expressed. If the
! 3011: alphabet name is absent, the Latin alphabet is used. When the alphabet name
! 3012: is present, only the first letter of the alphabet name is interpreted. Thus,
! 3013: the words <tt>Greek</tt> and <tt>Grec</tt> designate the same alphabet. In
1.30 cvs 3014: current versions of Thot, only the Greek and Latin alphabets are
3015: available.</p>
1.18 cvs 3016: <pre> 'CONST' ConstSeq
1.30 cvs 3017: ConstSeq = Const < Const > .
1.1 cvs 3018: Const = ConstID '=' ConstType ConstValue ';' .
3019: ConstID = NAME .
3020: ConstType ='Text' [ Alphabet ] / 'Symbol' /
3021: 'Graphics' / 'Picture' .
3022: ConstValue = STRING .
1.18 cvs 3023: Alphabet = NAME .</pre>
1.30 cvs 3024:
3025: <p>For character strings in the Latin alphabet (ISO Latin-1 character set),
1.1 cvs 3026: characters having codes higher than 127 (decimal) are represented by their
1.18 cvs 3027: code in octal.</p>
1.30 cvs 3028:
3029: <p>In the case of a symbol or graphical element, the value only contains a
1.37 ! cvs 3030: single character, between apostrophes, which indicates the form of the
! 3031: element which must be drawn in the box whose content is the constant. The
! 3032: symbol or graphical element takes the dimensions of the box, which are
! 3033: determined by the <tt>Height</tt> and <tt>Width</tt> rules. See <a
! 3034: href="#sectb72">table of codes</a> for the symbols and graphical elements.</p>
1.30 cvs 3035:
1.18 cvs 3036: <blockquote class="example">
1.30 cvs 3037: <p><strong>Example:</strong></p>
3038:
3039: <p>The constants ``Summary:'' and fraction bar, which were described
3040: earlier, are declared:</p>
3041: <pre>CONST
1.1 cvs 3042: SummaryConst = Text 'Summary:';
1.18 cvs 3043: Bar = Graphics 'h';</pre>
3044: </blockquote>
3045: </div>
1.1 cvs 3046:
1.18 cvs 3047: <div class="subsection">
1.37 ! cvs 3048: <h3><a name="sectc426" id="sectc426">Variables</a></h3>
1.1 cvs 3049:
1.37 ! cvs 3050: <p>Variables permit the definition of computed content for presentation
! 3051: boxes. A variable is associated with a presentation box by a <tt>Content</tt>
! 3052: rule; but before being used in a <tt>Content</tt> rule, a variable can be
! 3053: defined in the <tt>VAR</tt> section. It is also possible to define a variable
! 3054: at the time of its use in a <tt>Content</tt> rule, as can be done with a
1.30 cvs 3055: constant.</p>
3056:
3057: <p>A variable has a name and a value which is a character string resulting
1.37 ! cvs 3058: from the concatenation of the values of a sequence of functions. Each
1.30 cvs 3059: variable declaration is composed of the variable name followed by a colon and
1.37 ! cvs 3060: the sequence of functions which produces its value, separated by spaces. Each
1.18 cvs 3061: declaration is terminated by a semi-colon.</p>
3062: <pre> 'VAR' VarSeq
1.30 cvs 3063: VarSeq = Variable < Variable > .
1.1 cvs 3064: Variable = VarID ':' FunctionSeq ';' .
3065: VarID = NAME .
1.30 cvs 3066: FunctionSeq = Function < Function > .</pre>
3067:
1.37 ! cvs 3068: <p>Several functions are available. The first two return, in the form of a
! 3069: character string, the current date. <tt>DATE</tt> returns the date in
1.18 cvs 3070: English, while <tt>FDATE</tt> returns the date in french.</p>
1.30 cvs 3071:
3072: <p>Two other functions, <tt>DocName</tt> and <tt>DirName</tt>, return the
1.18 cvs 3073: document name and the directory where the document is stored.</p>
1.30 cvs 3074:
3075: <p>Function <tt>ElemName</tt> returns the type of the element which created
3076: the presentation box whose contents are the variable.</p>
3077:
3078: <p>Another function simply returns the value of a presentation constant. For
3079: any constant declared in the <tt>CONST</tt> section, it is sufficient to give
1.37 ! cvs 3080: the name of the constant. Otherwise, the type and value of the constant must
1.30 cvs 3081: be given, using the same form as in a <a href="#sectc425">constant
1.18 cvs 3082: declaration</a>. If the constant is not of type text, (types <tt>Symbol</tt>,
3083: <tt>Graphics</tt> or <tt>Picture</tt>), it must be alone in the variable
3084: definition; only constants of type <tt>Text</tt> can be mixed with other
3085: functions.</p>
1.30 cvs 3086:
3087: <p>It is also possible to obtain the value of an attribute, simply by
1.37 ! cvs 3088: mentioning the attribute's name. The value of this function is the value of
1.30 cvs 3089: the attribute for the element which created the presentation box whose
1.37 ! cvs 3090: contents are the variable. If the creating element does not have the
! 3091: indicated attribute, the value is an empty string. In the case of a numeric
1.30 cvs 3092: attribute, the attribute is translated into a decimal number in arabic
1.37 ! cvs 3093: numerals. If another form is desired, the <tt>VALUE</tt> function must be
1.30 cvs 3094: used.</p>
3095:
3096: <p>The last available function returns, as a character string, the value of a
1.1 cvs 3097: counter, an attribute or a page number. This value can be presented in
1.37 ! cvs 3098: different styles. The keyword <tt>VALUE</tt> is followed (between
1.1 cvs 3099: parentheses) by the name of the counter, the name of the attribute, or the
1.18 cvs 3100: keyword <tt>PageNumber</tt> and the desired style, the two parameters being
1.37 ! cvs 3101: separated by a comma. The style is a keyword which indicates whether the
1.18 cvs 3102: value should be presented in arabic numerals (<tt>Arabic</tt>), lower-case
3103: roman numerals (<tt>LRoman</tt>), or upper-case roman numerals
3104: (<tt>URoman</tt>), or by an upper-case letter (<tt>Uppercase</tt>) or
3105: lower-case letter (<tt>Lowercase</tt>).</p>
1.30 cvs 3106:
3107: <p>For a page counter, the keyword <tt>PageNumber</tt> can be followed,
3108: between parentheses, by the name of the view from which to obtain the page
1.37 ! cvs 3109: number. By default, the first view declared in the <tt>VIEWS</tt> section is
! 3110: used. The value obtained is the number of the page on which is found the
1.30 cvs 3111: element that is using the variable in a <tt>Content</tt> rule.</p>
3112:
3113: <p>For an ordinary counter, the name of the counter can be preceded by the
1.37 ! cvs 3114: keyword <tt>MaxRangeVal</tt> or <tt>MinRangeVal</tt>. These keywords mean
1.1 cvs 3115: that the value returned by the function is the maximum (minimum resp.) value
3116: taken by the counter in the whole document, not the value for the element
1.18 cvs 3117: concerned by the function.</p>
3118: <pre> Function = 'DATE' / 'FDATE' /
1.1 cvs 3119: 'DocName' / 'DirName' /
3120: 'ElemName' / 'AttributeName' /
3121: ConstID / ConstType ConstValue /
3122: AttrID /
3123: 'VALUE' '(' PageAttrCtr ','
3124: CounterStyle ')' .
1.6 cvs 3125: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
1.1 cvs 3126: [ MinMax ] CounterID / AttrID .
3127: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
3128: 'Uppercase' / 'Lowercase' .
1.18 cvs 3129: MinMax = 'MaxRangeVal' / 'MinRangeVal' .</pre>
1.30 cvs 3130:
1.18 cvs 3131: <blockquote class="example">
1.30 cvs 3132: <p><strong>Example:</strong></p>
3133:
3134: <p>To make today's date appear at the top of the first page of a report, a
3135: <a href="#sectc4232"><tt>CREATE</tt> rule</a> associated with the
3136: Report_Title element type generates a presentation box whose content
3137: (specified by the <tt>Content</tt> rule of that presentation box) is the
3138: variable:</p>
3139: <pre>VAR
1.18 cvs 3140: Todays_date : TEXT 'Version of ' DATE;</pre>
1.30 cvs 3141:
3142: <p>To produce, before each section title, the chapter number (in upper-case
3143: roman numerals) followed by the section number (in arabic numerals), two
3144: counters must be defined:</p>
3145: <pre>COUNTERS
1.1 cvs 3146: ChapterCtr : RANK OF Chapter;
1.18 cvs 3147: SectionCtr : RANK OF Section;</pre>
1.30 cvs 3148:
3149: <p>and the Section_Title element must create a presentation box whose
3150: content is the variable</p>
3151: <pre>VAR
1.1 cvs 3152: SectionNum : VALUE (ChapterCtr, URoman) TEXT '-'
1.18 cvs 3153: VALUE (SectionCtr, Arabic);</pre>
1.30 cvs 3154:
3155: <p>In order to make the page number on which each section begins appear in
3156: the table of contents view next to the section title, each Section_Title
3157: element must create a presentation box, visible only in the table of
3158: contents view, whose content is the variable:</p>
3159: <pre>VAR
1.1 cvs 3160: TitlePageNume :
1.18 cvs 3161: VALUE (PageNumber(Full_text), Arabic);</pre>
3162: </blockquote>
3163: </div>
1.1 cvs 3164:
1.18 cvs 3165: <div class="subsection">
1.37 ! cvs 3166: <h3><a name="sectc427" id="sectc427">Default presentation rules</a></h3>
1.1 cvs 3167:
1.30 cvs 3168: <p>In order to avoid having to specify, for each element type defined in the
1.1 cvs 3169: structure schema, values for every one of the numerous presentation
1.34 cvs 3170: properties, the presentation schema allows the definition of a set of default
1.37 ! cvs 3171: presentation rules. These rules apply to all the boxes of the elements
1.1 cvs 3172: defined in the structure schema and to the presentation boxes and page layout
1.37 ! cvs 3173: boxes defined in the presentation schema. Only rules which differ from these
1.18 cvs 3174: default need to be specified in other sections of the presentation schema.</p>
1.30 cvs 3175:
3176: <p>For the primary view, the default rules can define every presentation
1.34 cvs 3177: property, but not the <a href="#presfunct">presentation functions</a> or the
1.18 cvs 3178: <a href="#sectc4223">linebreaking conditions</a> (the <tt>NoBreak1</tt>,
3179: <tt>NoBreak2</tt>, and <tt>Gather</tt> rules).</p>
1.30 cvs 3180:
3181: <p>In a presentation schema, the default presentation rules section is
3182: optional; in this case, the <tt>DEFAULT</tt> keyword is also absent and the
3183: following rules are considered to be the default rules:</p>
1.26 cvs 3184: <pre> Visibility: Enclosing =;
3185: VertRef: * . Left;
3186: HorizRef: Enclosed . HRef;
3187: Height: Enclosed . Height;
3188: Width: Enclosed . Width;
3189: VertPos: Top = Previous . Bottom;
3190: HorizPos: Left = Enclosing . Left;
3191: MarginTop: 0;
3192: MarginRight: 0;
3193: MarginBottom: 0;
3194: MarginLeft: 0;
3195: PaddingTop: 0;
3196: PaddingRight: 0;
3197: PaddingBottom: 0;
3198: PaddingLeft: 0;
3199: BorderTopWidth: 0;
3200: BorderRightWidth: 0;
3201: BorderBottomWidth: 0;
3202: BorderLeftWidth: 0;
3203: BorderTopColor: Foreground;
3204: BorderRightColor: Foreground;
3205: BorderBottomColor: Foreground;
3206: BorderLeftColor: Foreground;
3207: BorderTopStyle: None;
3208: BorderRightStyle: None;
3209: BorderBottomStyle: None;
3210: BorderLeftStyle: None;
3211: VertOverflow: No;
3212: HorizOverflow: No;
3213: Size: Enclosing =;
3214: Style: Enclosing =;
3215: Weight: Enclosing =;
3216: Font: Enclosing =;
3217: Underline: Enclosing =;
3218: Thickness: Enclosing =;
3219: Indent: Enclosing =;
3220: LineSpacing: Enclosing =;
3221: Adjust: Enclosing =;
3222: Hyphenate: Enclosing =;
3223: PageBreak: Yes;
3224: LineBreak: Yes;
3225: InLine: Yes;
3226: Depth: 0;
3227: LineStyle: Enclosing =;
3228: LineWeight: Enclosing =;
3229: FillPattern: Enclosing =;
3230: Background: Enclosing =;
3231: Foreground: Enclosing =;</pre>
1.30 cvs 3232:
3233: <p>If other values are desired for the default rules, they must be defined
1.37 ! cvs 3234: explicitly in the default rules section. In fact, it is only necessary to
1.1 cvs 3235: define those default rules which differ from the ones above, since the rules
1.18 cvs 3236: above will be used whenever a rule is not explicitly named.</p>
1.30 cvs 3237:
1.37 ! cvs 3238: <p>Default rules for views other than the primary view can also be specified.
1.1 cvs 3239: Otherwise, the default rules for the primary views are applied to the other
1.18 cvs 3240: views.</p>
1.30 cvs 3241:
3242: <p>Default rules are expressed in the same way as <a
3243: href="#sectc4215">explicit rules for document elements</a>.</p>
1.18 cvs 3244: </div>
1.1 cvs 3245:
1.18 cvs 3246: <div class="subsection">
1.37 ! cvs 3247: <h3><a name="sectc428" id="sectc428">Presentation and page layout
! 3248: boxes</a></h3>
1.1 cvs 3249:
1.30 cvs 3250: <p>The presentation process uses elements which are not part of the logical
1.1 cvs 3251: structure of the document, such as pages (which are the page layout boxes) or
3252: alternatively, rules, numbers, or words introducing certain parts of the
3253: document, such as ``Summary'', ``Appendices'', ``Bibliography'', etc. (which
1.18 cvs 3254: are presentation boxes).</p>
1.30 cvs 3255:
3256: <p>After the word <tt>BOXES</tt>, each presentation or page layout box is
3257: defined by its name and a sequence of presentation rules which indicate how
1.37 ! cvs 3258: they must be displayed. These rules are the same as those which define the
! 3259: boxes associated with element of the logical structure of the document, with
! 3260: a single exception, the <a href="#sectc4231"><tt>Content</tt> rule</a> which
! 3261: is used only to specify the content of presentation boxes. The content of
! 3262: boxes associated with elements of the document structure is defined in each
! 3263: document or object and thus is not specified in the presentation schema,
! 3264: which applies to all documents or objects of a class.</p>
1.30 cvs 3265:
3266: <p>Among the rules which define a presentation box, certain ones can refer to
1.37 ! cvs 3267: another presentation box (for example, in their positional rules). If the
1.1 cvs 3268: designated box is defined after the box which designates it, a
1.18 cvs 3269: <tt>FORWARD</tt> instruction followed by the name of the designated box must
3270: appear before the designation.</p>
3271: <pre> 'BOXES' BoxSeq
1.30 cvs 3272: BoxSeq = Box < Box > .
1.1 cvs 3273: Box ='FORWARD' BoxID ';' /
3274: BoxID ':' ViewRuleSeq .
1.18 cvs 3275: BoxID = NAME .</pre>
3276: </div>
1.1 cvs 3277:
1.18 cvs 3278: <div class="subsection">
1.37 ! cvs 3279: <h3><a name="sectc429" id="sectc429">Presentation of structured
! 3280: elements</a></h3>
1.1 cvs 3281:
1.30 cvs 3282: <p>After the words <tt>RULES</tt>, the presentation schema gives the
3283: presentation rules that apply to the elements whose types are defined in the
1.37 ! cvs 3284: structure schema. Only those rules which differ from the <a
1.18 cvs 3285: href="#sectc427">default</a> must be specified in the <tt>RULES</tt>
3286: section.</p>
1.30 cvs 3287:
3288: <p>The rule definitions for each element type are composed of the name of the
1.1 cvs 3289: element type (as specified in the structure schema) followed by a colon and
1.18 cvs 3290: the set of rules specific to that type.</p>
1.30 cvs 3291:
3292: <p>The type name can be preceded by a star in the special case where the
1.18 cvs 3293: structure schema defines an <a href="#sectd3284">inclusion</a> without
1.1 cvs 3294: expansion (or with partial expansion) of a type with the same name as an
1.18 cvs 3295: element of defined in the structure schema.</p>
1.30 cvs 3296:
3297: <p>In the case where the element is a <a href="#sectd3285">mark pair</a>, but
1.18 cvs 3298: only in this case, the type name can be preceded by the keywords
1.37 ! cvs 3299: <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
1.18 cvs 3300: that follow apply to the first or second mark of the pair.</p>
3301: <pre> 'RULES' PresentSeq
1.30 cvs 3302: PresentSeq = Present < Present > .
1.6 cvs 3303: Present = [ '*' ] [ FirstSec ] ElemID ':'
3304: ViewRuleSeq .
1.18 cvs 3305: FirstSec = 'First' / 'Second' .</pre>
1.30 cvs 3306:
3307: <p>A presentation schema can define presentation rules for base elements,
1.37 ! cvs 3308: which are defined implicitly in the structure schemas. In the English version
1.30 cvs 3309: of the presentation schema compiler, the base type names are the same as in
3310: the S language, but they are terminated by the <tt>_UNIT</tt> suffix:
1.18 cvs 3311: <tt>TEXT_UNIT</tt>, <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>,
1.37 ! cvs 3312: <tt>GRAPHICS_UNIT</tt>. The base type names are written in upper-case
1.18 cvs 3313: letters.</p>
3314: </div>
3315:
3316: <div class="subsection">
1.37 ! cvs 3317: <h3><a name="sectc4210" id="sectc4210">Logical attribute presentation</a></h3>
1.18 cvs 3318:
1.30 cvs 3319: <p>After the keyword <tt>ATTRIBUTES</tt>, all attributes which are to have
1.37 ! cvs 3320: some effect on the presentation of the element to which they are attached
! 3321: must be mentioned, along with the corresponding presentation rules. This is
! 3322: true for both global attributes (which can be attached to all element types)
! 3323: and local attributes (which can only be attached to certain element
! 3324: types).</p>
1.30 cvs 3325:
3326: <p>Also mentioned in this section are attributes which imply an effect on
1.1 cvs 3327: elements in the subtree of the element to which they are attached. The
1.37 ! cvs 3328: presentation of these descendants can be modified as a function of the value
1.1 cvs 3329: of the attribute which they inherit, just as if it was attached to them
1.18 cvs 3330: directly.</p>
1.30 cvs 3331:
3332: <p>The specification for each attribute includes the attribute's name,
3333: followed by an optional value specification and, after a colon, a set of
1.37 ! cvs 3334: rules. The set of rules must contain at least one rule.</p>
1.30 cvs 3335:
1.37 ! cvs 3336: <p>When there is no value specification, the rules are applied to all
! 3337: elements which carry the attribute, no matter what their value. When the
! 3338: rules must only apply when the attribute has certain values, these values
! 3339: must be specified. Thus, the same attribute can appear in the
! 3340: <tt>ATTRIBUTES</tt> section several times, with each appearance having a
! 3341: different value specification. However, reference attributes never have a
! 3342: value specification and, as a result, can only appear once in the
! 3343: <tt>ATTRIBUTES</tt> section.</p>
1.30 cvs 3344:
3345: <p>To specify that the presentation rules apply to some of the descendants of
3346: the element having the attribute, the name of the affected element type is
1.37 ! cvs 3347: given, between parentheses, after the attribute name. This way, the
! 3348: presentation rules for the attribute will be applied to the element having
! 3349: the attribute, if it is of the given type, and to all of its descendants of
! 3350: the given type. In the case where this type is a <a href="#sectd3285">mark
! 3351: pair</a>, but only in this case, the type name can be preceded by the
! 3352: keywords <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether
! 3353: the rules that follow apply to the first or second mark of the pair. If the
! 3354: rule must apply to several different element types, the specification must be
! 3355: repeated for each element type.</p>
1.30 cvs 3356:
3357: <p>The specification of values for which the presentation rules will be
3358: applied varies according to the type of the attribute:</p>
1.18 cvs 3359: <dl>
1.30 cvs 3360: <dt>numeric attribute</dt>
3361: <dd>If the rules are to apply for one value of the attribute, then the
1.37 ! cvs 3362: attribute name is followed by an equals sign and this value. If the
1.30 cvs 3363: rules are to apply for all values less than (or greater than) a
3364: threshold value, non-inclusive, the attribute name followed by a '<'
1.37 ! cvs 3365: sign (or a '>' sign, respectively) and the threshold value. If the
! 3366: rules must apply to a range of values, the attribute name is followed
! 3367: by the word '<tt>IN</tt>' and the two bounds of the range, enclosed in
! 3368: brackets and separated by two periods ('<tt>..</tt>'). In the case of
! 3369: ranges, the values of the bounds are included in the range.
1.30 cvs 3370: <p>The threshold value in the comparisons can be the value of an
1.37 ! cvs 3371: attribute attached to an ancestor element. In this case, the attribute
1.30 cvs 3372: name is given instead of a constant value.</p>
1.37 ! cvs 3373: <p>It is also possible to write rules which apply only when a
! 3374: comparison between two different attributes of the element's ancestors
! 3375: is true. In this case, the first attribute name is followed by a
! 3376: comparison keyword and the name of the second attribute. The comparison
! 3377: keywords are <tt>EQUAL</tt> (simple equality), <tt>LESS</tt>
! 3378: (non-inclusive less than), and <tt>GREATER</tt> (non-inclusive greater
! 3379: than).</p>
1.30 cvs 3380: </dd>
3381: <dt>text attribute</dt>
3382: <dd>If the rules are to apply for one value of the attribute, then the
3383: attribute name is followed by an equals sign and this value.</dd>
3384: <dt>reference attribute</dt>
3385: <dd>There is never a value specification; the rules apply no matter what
3386: element is designated by the attribute.</dd>
3387: <dt>enumerated attribute</dt>
3388: <dd>If the rules are to apply for one value of the attribute, then the
3389: attribute name is followed by an equals sign and this value.</dd>
1.18 cvs 3390: </dl>
1.30 cvs 3391:
3392: <p>The order in which the rules associated with a numeric attribute are
1.37 ! cvs 3393: defined is important. When multiple sets of rules can be applied, the first
1.30 cvs 3394: set declared is the one used.</p>
3395:
3396: <p>Rules for attributes have priority over both default rules and rules
1.37 ! cvs 3397: associated with element types. The attribute rules apply to the element to
! 3398: which the attribute is attached. It is the rules which apply to the
1.1 cvs 3399: surrounding elements (and especially to the descendants) which determine the
3400: effect of the attribute rules on the environment ( and especially on the
1.18 cvs 3401: terminal elements of the structure).</p>
3402: <pre> 'ATTRIBUTES' PresAttrSeq
1.30 cvs 3403: PresAttrSeq = PresAttr < PresAttr > .
1.1 cvs 3404: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
3405: [ AttrRelation ] ':' ViewRuleSeq .
3406: AttrID = NAME .
3407: AttrRelation ='=' AttrVal /
1.30 cvs 3408: '>' [ '-' ] MinValue /
1.1 cvs 3409: '<' [ '-' ] MaxValue /
3410: 'IN' '[' [ '-' ] LowerBound '..'
3411: [ '-' ] UpperBound ']' /
3412: 'GREATER' AttrID /
3413: 'EQUAL' AttrID /
3414: 'LESS' AttrID .
3415: AttrVal = [ '-' ] EqualNum / EqualText /
3416: AttrValue .
3417: MinValue = NUMBER .
3418: MaxValue = NUMBER .
3419: LowerBound = NUMBER .
3420: UpperBound = NUMBER.
3421: EqualNum = NUMBER .
3422: EqualText = STRING .
1.18 cvs 3423: AttrValue = NAME .</pre>
1.30 cvs 3424:
1.37 ! cvs 3425: <p>In presentation rules associated with a numeric attribute (and only in
! 3426: such rules), the attribute name can be used in place of a numeric value. In
! 3427: this case, the value of the attribute is used in the application of the rule.
! 3428: Thus, the attribute can represent a relation between the size of two boxes,
! 3429: the height and width of a box, the height of an area where page breaks are
! 3430: prohibited, the distance between two boxes, the position of the reference
! 3431: axis of a box, the interline spacing, the indentation of the first line, the
1.18 cvs 3432: visibility, the depth (z-order), or the character set.</p>
1.30 cvs 3433:
1.37 ! cvs 3434: <p>The presentation rules associated with reference attributes, it is
! 3435: possible to use the element designated by the attribute as a reference box in
! 3436: a positional or extent rule. This element is represented in the <a
1.18 cvs 3437: href="#sectc4218">position</a> or <a href="#sectc4219">extent</a> rule by the
3438: keyword <tt>Referred</tt>.</p>
1.30 cvs 3439:
1.18 cvs 3440: <blockquote class="example">
1.30 cvs 3441: <p><strong>Example:</strong></p>
3442:
1.37 ! cvs 3443: <p>In all structure schemas, there is a global Language attribute defined
! 3444: as follows:</p>
1.30 cvs 3445: <pre>ATTR
1.18 cvs 3446: Language = TEXT;</pre>
1.30 cvs 3447:
3448: <p>The following rules would make French text be displayed in roman
3449: characters and English text be displayed in italics:</p>
3450: <pre>ATTRIBUTES
1.1 cvs 3451: Language = 'French' :
1.6 cvs 3452: Style : Roman;
1.1 cvs 3453: Language = 'English' :
1.18 cvs 3454: Style : Italics;</pre>
1.30 cvs 3455:
3456: <p>Using these rules, when the user puts the Language attribute with the
3457: value 'English' on the summary of a document, every character string
1.37 ! cvs 3458: (terminal elements) contained in the summary are displayed in italics. See
1.30 cvs 3459: the <a href="#sectd42252"><tt>Style</tt> rule</a>.</p>
1.18 cvs 3460: </blockquote>
1.30 cvs 3461:
1.18 cvs 3462: <blockquote class="example">
1.30 cvs 3463: <p><strong>Example:</strong></p>
3464:
3465: <p>A numeric attribute representing the importance of the part of the
3466: document to which it is attached can be defined:</p>
3467: <pre>ATTR
1.18 cvs 3468: Importance = INTEGER;</pre>
1.30 cvs 3469:
3470: <p>In the presentation schema, the importance of an element is reflected in
3471: the choice of character size, using the following rules.</p>
3472: <pre>ATTRIBUTES
1.1 cvs 3473: Importance < 2 :
3474: Size : 1;
3475: Importance IN [2..4] :
3476: Size : Importance;
3477: Importance = 10 :
3478: Size : 5;
1.30 cvs 3479: Importance > 4 :
1.18 cvs 3480: Size : 4;</pre>
1.30 cvs 3481:
3482: <p>Thus, the character size corresponds to the value of the Importance
3483: attribute; its value is</p>
3484: <ul>
3485: <li>the value of the Importance attribute when the value is between 2 and
3486: 4 (inclusive),</li>
3487: <li>1, when the value of the Importance attribute is less than 2,</li>
3488: <li>4, when the value of the Importance attribute is greater than 4,</li>
3489: <li>5, when the value of the Importance attribute is 10.</li>
3490: </ul>
3491:
1.37 ! cvs 3492: <p>The last case (value 5) must be defined before the case which handles
! 3493: all Importance values greater than 4, because the two rules are not
! 3494: disjoint and the first one defined will have priority. Otherwise, when the
! 3495: Importance attribute has value 10, the font size will be 4.</p>
1.18 cvs 3496: </blockquote>
1.30 cvs 3497:
1.18 cvs 3498: <blockquote class="example">
1.30 cvs 3499: <p><strong>Example:</strong></p>
3500:
3501: <p>Suppose the structure defines a list element which can have an attribute
3502: defining the type of list (numbered or not):</p>
3503: <pre>STRUCT
1.1 cvs 3504: list (ATTR list_type = enumeration, dash)
1.18 cvs 3505: = LIST OF (list_item = TEXT);</pre>
1.30 cvs 3506:
3507: <p>Then, the presentation schema could use the attribute placed on the list
3508: element to put either a dash or a number before the each element of the
3509: list:</p>
3510: <pre>ATTRIBUTES
1.1 cvs 3511: list_type (list_item) = enumeration :
3512: CreateBefore (NumberBox);
3513: list_type (list_item) = dash :
1.18 cvs 3514: CreateBefore (DashBox);</pre>
3515: </blockquote>
1.30 cvs 3516:
1.18 cvs 3517: <blockquote class="example">
1.30 cvs 3518: <p><strong>Example:</strong></p>
3519:
1.37 ! cvs 3520: <p>Suppose that two attributes are defined in the structure schema. The
! 3521: first is a numeric global attribute called ``version''. The other is a
1.30 cvs 3522: local attribute defined on the root of the document called
3523: ``Document_version'':</p>
3524: <pre>STRUCTURE Document
1.1 cvs 3525: ATTR
3526: version = INTEGER;
3527: STRUCT
3528: Document (ATTR Document_version = INTEGER) =
3529: BEGIN
3530: SomeElement ;
3531: ...
3532: SomeOtherElement ;
3533: END ;
1.18 cvs 3534: ...</pre>
1.30 cvs 3535:
3536: <p>These attributes can be used in the presentation schema to place change
3537: bars in the margin next to elements whose version attribute has a value
3538: equal to the Document_version attribute of the root and to place a star in
3539: margin of elements whose version attribute is less than the value of the
3540: root's Document_version attribute:</p>
3541: <pre>ATTRIBUTES
1.1 cvs 3542: version EQUAL Document_version :
3543: CreateBefore (ChangeBarBox) ;
3544: version LESS Document_version :
1.18 cvs 3545: CreateBefore (StarBox) ;</pre>
3546: </blockquote>
3547: </div>
1.1 cvs 3548:
1.18 cvs 3549: <div class="subsection">
1.37 ! cvs 3550: <h3><a name="sectc4212" id="sectc4212">Value transmission rules</a></h3>
1.1 cvs 3551:
1.30 cvs 3552: <p>The last section of a presentation schema, which is optional, serves to
1.1 cvs 3553: defines the way in which a document transmits certain values to its
1.37 ! cvs 3554: sub-documents. A sub-document is an document <a
1.18 cvs 3555: href="#inclusion">included</a> without expansion or with partial expansion.
1.1 cvs 3556: The primary document can transmit to its sub-documents the values of certain
3557: counters or the textual content of certain of its elements, as a function of
1.18 cvs 3558: their type.</p>
1.30 cvs 3559:
3560: <p>The sub-documents receive these values in attributes which must be defined
1.37 ! cvs 3561: in their structure schema as local attributes of the root element. The types
1.30 cvs 3562: of these attributes must correspond to the type of the value which they
3563: receive: numeric attributes for receiving the value of a counter, textual
3564: attributes for receiving the content of an element.</p>
3565:
3566: <p>In the structure schema of the primary document, there appears at the end,
1.37 ! cvs 3567: after the <tt>TRANSMIT</tt> keyword, a sequence of transmission rules. Each
1.1 cvs 3568: rule begins with the name of the counter to transmit or of the element type
1.37 ! cvs 3569: whose textual content will be transmitted. This name is followed by the
! 3570: keyword <tt>To</tt> and the name of the attribute of the sub-document to
! 3571: which the value is transmitted. The sub-document class is indicated between
! 3572: parentheses after the name of the attribute. The transmission rule ends with
1.18 cvs 3573: a semicolon.</p>
1.30 cvs 3574: <pre> TransmitSeq = Transmit < Transmit > .
1.1 cvs 3575: Transmit = TypeOrCounter 'To' ExternAttr
3576: '(' ElemID ')' ';' .
3577: TypeOrCounter = CounterID / ElemID .
1.18 cvs 3578: ExternAttr = NAME .</pre>
1.30 cvs 3579:
1.18 cvs 3580: <blockquote class="example">
1.30 cvs 3581: <p><strong>Example:</strong></p>
3582:
3583: <p>Consider a Book document class which includes instances of the Chapter
1.37 ! cvs 3584: document class. These classes might have the following schemas:</p>
1.30 cvs 3585: <pre>STRUCTURE Book
1.1 cvs 3586: STRUCT
3587: Book = BEGIN
3588: Title = Text;
3589: Body = LIST OF (Chapter INCLUDED);
3590: END;
3591: ...
3592:
3593: STRUCTURE Chapter
3594: STRUCT
3595: Chapter (ATTR FirstPageNum = Integer;
3596: ChapterNum = Integer;
3597: CurrentTitle = Text) =
1.6 cvs 3598: BEGIN
3599: ChapterTitle = Text;
3600: ...
3601: END;
1.18 cvs 3602: ...</pre>
1.30 cvs 3603:
3604: <p>Then the presentation schema for books could define chapter and page
3605: counters. The following transmission rules in the book presentation schema
3606: would transmit values for the three attributes defined at the root of each
3607: chapter sub-document.</p>
3608: <pre>PRESENTATION Book;
1.1 cvs 3609: VIEWS
3610: Full_text;
3611: COUNTERS
3612: ChapterCtr: Rank of Chapter;
3613: PageCtr: Rank of Page(Full_text);
3614: ...
3615: TRANSMIT
3616: PageCtr TO FirstPageNum(Chapter);
3617: ChapterCtr TO ChapterNum(Chapter);
3618: Title TO CurrentTitle(Chapter);
1.18 cvs 3619: END</pre>
1.30 cvs 3620:
3621: <p>Thus, each chapter included in a book can number its pages as a function
3622: of the number of pages preceding it in the book, can make the chapter's
3623: number appear before the number of each of its sections, or can place the
3624: title of the book at the top of each page.</p>
1.18 cvs 3625: </blockquote>
3626: </div>
1.1 cvs 3627:
1.18 cvs 3628: <div class="subsection">
1.37 ! cvs 3629: <h3><a name="sectc4213" id="sectc4213">Presentation rules</a></h3>
1.1 cvs 3630:
1.30 cvs 3631: <p>Whether defining the appearance of a presentation or page layout box, an
1.1 cvs 3632: element type, or an attribute value, the set of presentation rules that apply
1.18 cvs 3633: is always defined in the same way.</p>
1.30 cvs 3634:
3635: <p>Normally, a set of presentation rules is placed between the keywords
1.18 cvs 3636: <tt>BEGIN</tt> and <tt>END</tt>, the keyword <tt>END</tt> being followed by a
1.37 ! cvs 3637: semicolon. The first section of this block defines the rules that apply to
1.18 cvs 3638: the primary view, if the <a href="#sectc427">default rules</a> are not
1.37 ! cvs 3639: completely suitable. Next comes the rules which apply to specific other
1.1 cvs 3640: views, with a rule sequence for each view for which the default rules are not
1.37 ! cvs 3641: satisfactory. If the default rules are suitable for the non-primary views,
! 3642: there will not be any specific rules for these views. If there is only one
1.18 cvs 3643: rule which applies to all views then the keywords <tt>BEGIN</tt> and
3644: <tt>END</tt> need not appear.</p>
1.30 cvs 3645:
3646: <p>For each view, it is only necessary to specify those rules which differ
3647: from the default rules for the view, so that for certain views (or even all
3648: views), there may be no specific rules.</p>
3649:
3650: <p>The specific rules for a non-primary view are introduced by the <a
1.37 ! cvs 3651: name="inkeyword" id="inkeyword"><tt>IN</tt> keyword</a>, followed by the view
! 3652: name. The rules for that view follow, delimited by the keywords
! 3653: <tt>BEGIN</tt> and <tt>END</tt>, or without these two keywords when there is
! 3654: only one rule.</p>
1.30 cvs 3655:
3656: <p><strong>Note:</strong> the view name which follows the <tt>IN</tt> keyword
1.1 cvs 3657: must not be the name of the primary view, since the rules for that view are
1.18 cvs 3658: found before the rules for the other views.</p>
1.30 cvs 3659:
3660: <p>Within each block concerning a view, other blocks can appear, delimited by
1.37 ! cvs 3661: the same keywords <tt>BEGIN</tt> and <tt>END</tt>. Each of these blocks
! 3662: gathers the presentation rules that apply, for a given view, only when a
! 3663: given condition is satisfied. Each block is preceded by a condition
! 3664: introduced by the <tt>IF</tt> keyword. If such a conditional block contains
! 3665: only one rule, the keywords <tt>BEGIN</tt> and <tt>END</tt> can be
! 3666: omitted.</p>
! 3667:
! 3668: <p>Although the syntax allows any presentation rule to appear in a
! 3669: conditional block, only <a href="#sectc4232">creation rules</a> are allowed
! 3670: after any condition; other rules are allowed only after conditions
! 3671: <tt>Within</tt> and ElemID. In addition, the following rules cannot be
! 3672: conditional: <tt>PageBreak, LineBreak, Inline, Gather</tt>.</p>
1.30 cvs 3673:
3674: <p>For a given view, the rules that apply without any condition must appear
1.37 ! cvs 3675: before the first conditional block. If some rules apply only when none of the
! 3676: specified condition holds, they are grouped in a block preceded by the
! 3677: keyword <tt>Otherwise</tt>, and that block must appear after the last
! 3678: conditionnal block concerning the same view.</p>
1.30 cvs 3679: <pre> ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 3680: 'END' ';' /
3681: ViewRules / CondRules / Rule .
3682: RulesAndCond = CondRules / Rule .
3683: ViewRules = 'IN' ViewID CondRuleSeq .
1.30 cvs 3684: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
1.1 cvs 3685: CondRules / Rule .
1.30 cvs 3686: CondRules = CondRule < CondRule >
1.1 cvs 3687: [ 'Otherwise' RuleSeq ] .
3688: CondRule = 'IF' ConditionSeq RuleSeq .
1.30 cvs 3689: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' /
1.18 cvs 3690: Rule .</pre>
1.30 cvs 3691:
1.18 cvs 3692: <blockquote class="example">
1.30 cvs 3693: <p><strong>Example:</strong></p>
3694:
3695: <p>The following rules for a report's title make the title visible in the
1.37 ! cvs 3696: primary view and invisible in the table of contents and in the formula
! 3697: views (see the <a href="#sectc4224"><tt>Visibility</tt> rule</a>).</p>
1.30 cvs 3698: <pre>Title : BEGIN
1.1 cvs 3699: Visibility : 1;
3700: ... {Other rules for the primary view}
3701: IN Table_of_contents
3702: Visibility : 0;
3703: IN Formulas
3704: Visibility : 0;
1.18 cvs 3705: END;</pre>
3706: </blockquote>
3707: </div>
1.1 cvs 3708:
1.18 cvs 3709: <div class="subsection">
1.37 ! cvs 3710: <h3><a name="sectc4214" id="sectc4214">Conditions applying to presentation
! 3711: rules</a></h3>
1.1 cvs 3712:
1.37 ! cvs 3713: <p>Many conditions can be applied to presentation rules. Conditions allow
! 3714: certain presentation rules to apply only in certain cases. These conditions
! 3715: can be based on the structural position of the element. They can be based on
1.1 cvs 3716: whether the element has references, and what type of references, whether the
1.33 cvs 3717: element has attributes, whether the element is empty or not, whether the
3718: element is the root of its document or not. They can also be based on the
3719: value of a counter.</p>
1.30 cvs 3720:
1.37 ! cvs 3721: <p>It is possible to specify several conditions which must all be true for
! 3722: the rules to apply.</p>
1.30 cvs 3723:
1.37 ! cvs 3724: <p>A set of conditions is specified by the <tt>IF</tt> keyword. This keyword
1.30 cvs 3725: is followed by the sequence of conditions, separated by the <tt>AND</tt>
3726: keyword. Each condition is specified by a keyword which defines the condition
3727: type. In some cases, the keyword is followed by other data, which specify the
3728: condition more precisely.</p>
3729:
3730: <p>An elementary condition can be negative; it is then preceded by the
1.18 cvs 3731: <tt>NOT</tt> keyword.</p>
1.30 cvs 3732:
3733: <p>When the presentation rule(s) controlled by the condition apply to a
3734: reference element or a reference attribute, an elementary condition can also
1.37 ! cvs 3735: apply to element referred by this reference. The <tt>Target</tt> keyword is
! 3736: used for that purpose. It must appear before the keyword defining the
1.30 cvs 3737: condition type.</p>
1.18 cvs 3738: <pre> CondRule ='IF' ConditionSeq RuleSeq .
1.30 cvs 3739: ConditionSeq = Condition < 'AND' Condition > .
1.1 cvs 3740: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
3741: ConditionElem ='First' / 'Last' /
3742: [ 'Immediately' ] 'Within' [ NumParent ]
3743: ElemID [ ExtStruct ] /
3744: ElemID /
3745: 'Referred' / 'FirstRef' / 'LastRef' /
3746: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
3747: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
3748: 'UserPage' / 'StartPage' / 'ComputedPage' /
1.33 cvs 3749: 'Empty' / 'Root' /
1.1 cvs 3750: '(' [ MinMax ] CounterName CounterCond ')' /
3751: CondPage '(' CounterID ')' .
3752: NumParent = [ GreaterLess ] NParent .
1.30 cvs 3753: GreaterLess ='>' / '<' .
1.1 cvs 3754: NParent = NUMBER.
1.6 cvs 3755: ExtStruct ='(' ElemID ')' .
1.30 cvs 3756: CounterCond ='<' MaxCtrVal / '>' MinCtrVal /
1.1 cvs 3757: '=' EqCtrVal /
3758: 'IN' '[' ['-'] MinCtrBound '.' '.'
3759: ['-'] MaxCtrBound ']' .
3760: PageCond ='Even' / 'Odd' / 'One' .
3761: MaxCtrVal = NUMBER .
3762: MinCtrVal = NUMBER .
3763: EqCtrVal = NUMBER .
3764: MaxCtrBound = NUMBER .
1.18 cvs 3765: MinCtrBound = NUMBER .</pre>
1.1 cvs 3766:
1.18 cvs 3767: <div class="subsubsection">
1.37 ! cvs 3768: <h4><a name="sectd42141" id="sectd42141">Conditions based on the logical
! 3769: position of the element</a></h4>
1.30 cvs 3770:
3771: <p>The condition can be on the position of the element in the document's
1.37 ! cvs 3772: logical structure tree. It is possible to test whether the element is the
1.30 cvs 3773: first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
3774: not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>). These
1.18 cvs 3775: conditions can be associated only with <a href="#sectc4232">creation
3776: rules</a>.</p>
1.30 cvs 3777:
1.33 cvs 3778: <p>It is possible to test if the element is the root of its document (keyword
3779: <code>Root</code>).</p>
3780:
1.30 cvs 3781: <p>It is also possible to test if the element is contained in an element of a
1.18 cvs 3782: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). The type
3783: is indicated after the keyword <tt>Within</tt>. If that element type is
1.1 cvs 3784: defined in a structure schema which is not the one which corresponds to the
3785: presentation schema, the type name of this element must be followed, between
1.18 cvs 3786: parentheses, by the name of the structure schema which defines it.</p>
1.30 cvs 3787:
3788: <p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
1.18 cvs 3789: condition is satisfied only if the <em>parent</em> element has the type
3790: indicated. If the word <tt>Immediately</tt> is missing, the condition is
3791: satisfied if any <em>ancestor</em> has the type indicated.</p>
1.30 cvs 3792:
3793: <p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.37 ! cvs 3794: type. It specifies the number of ancestors of the indicated type that must be
! 3795: present for the condition to be satisfied. If the keyword
1.18 cvs 3796: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
1.37 ! cvs 3797: element must have the indicated type. The integer <i>n</i> must be positive
! 3798: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
! 3799: maximum or minimum number of ancestors. If these symbols are missing, the
! 3800: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
1.30 cvs 3801: this number is missing, it is equivalent to > 0.</p>
3802:
3803: <p>If the condition applies to presentation rules associated with an
3804: attribute, in the <tt>ATTRIBUTES</tt> section of the presentation schema, the
3805: condition can be simply an element name. Presentation rules are then executed
3806: only if the attribute is attached to an element of that type. The keyword
3807: <tt>NOT</tt> before the element name indicates that the presentation rules
3808: must be executed only if the element is not of the type indicated.</p>
1.18 cvs 3809: </div>
1.1 cvs 3810:
1.18 cvs 3811: <div class="subsubsection">
1.37 ! cvs 3812: <h4><a name="sectd42142" id="sectd42142">Conditions on references</a></h4>
1.30 cvs 3813:
3814: <p>References may be taken into account in conditions, which can be based on
3815: the fact that the element, or one of its ancestors, is designated by a at
3816: least one reference (<tt>Referred</tt>) or by none (<tt>NOT
3817: Referred</tt>).</p>
3818:
3819: <p>If the element or attribute to which the condition is attached is a
3820: reference, the condition can be based on the fact that it acts as the first
3821: reference to the designated element (<tt>FirstRef</tt>), or as the last
3822: (<tt>LastRef</tt>), or as a reference to an element located in another
3823: document (<tt>ExternalRef</tt>) or in the same document
3824: (<tt>InternalRef</tt>).</p>
1.1 cvs 3825:
1.30 cvs 3826: <p>The condition can also be based on the fact that the element is an <a
1.37 ! cvs 3827: href="#inclusion">inclusion</a>. This is noted (<tt>CopyRef</tt>).</p>
1.30 cvs 3828:
3829: <p>Like all conditions, conditions on references can be inverted by the
1.18 cvs 3830: <tt>NOT</tt> keyword. These conditions can be associated only with <a
3831: href="#sectc4232">creation rules</a>.</p>
3832: </div>
1.1 cvs 3833:
1.18 cvs 3834: <div class="subsubsection">
1.37 ! cvs 3835: <h4><a name="sectd42143" id="sectd42143">Conditions on logical
! 3836: attributes</a></h4>
1.30 cvs 3837:
3838: <p>The condition can be based on the presence or absence of attributes
3839: associated with the element, no matter what the attributes or their values.
3840: The <tt>AnyAttributes</tt> keyword expresses this condition.</p>
1.1 cvs 3841:
1.30 cvs 3842: <p>If the condition appears in the presentation rules of an attribute, the
1.37 ! cvs 3843: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate
! 3844: that the rules must only be applied if this attribute is the first attribute
! 3845: for the element or if it is the last (respectively). These conditions can
! 3846: also be inverted by the <tt>NOT</tt> keyword. These conditions can be
! 3847: associated only with <a href="#sectc4232">creation rules</a>.</p>
1.30 cvs 3848:
3849: <p>It is also possible to apply certain presentation rules only when the
3850: element being processed or one of its ancestors has a certain attribute,
1.37 ! cvs 3851: perhaps with a certain value. This can be done in the <a
1.18 cvs 3852: href="#sectc4210"><tt>ATTRIBUTES</tt> section</a>.</p>
3853: </div>
1.1 cvs 3854:
1.18 cvs 3855: <div class="subsubsection">
1.37 ! cvs 3856: <h4><a name="sectd42144" id="sectd42144">Conditions on page breaks</a></h4>
1.1 cvs 3857:
1.30 cvs 3858: <p>The page break base type (and only this type) can use the following
1.18 cvs 3859: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, and <tt>UserPage</tt>.
3860: The <tt>ComputedPage</tt> condition indicates that the presentation rule(s)
1.37 ! cvs 3861: should apply if the page break was created automatically by Thot; the
! 3862: <tt>StartPage</tt> condition is true if the page break is generated before
! 3863: the element by the <tt>Page</tt> rule; and the <tt>UserPage</tt> condition
! 3864: applies if the page break was inserted by the user.</p>
1.30 cvs 3865:
3866: <p>These conditions can be associated only with <a href="#sectc4232">creation
1.18 cvs 3867: rules</a>.</p>
3868: </div>
1.1 cvs 3869:
1.18 cvs 3870: <div class="subsubsection">
1.37 ! cvs 3871: <h4><a name="sectd42145" id="sectd42145">Conditions on the element's
! 3872: content</a></h4>
1.1 cvs 3873:
1.37 ! cvs 3874: <p>The condition can be based on whether or not the element is empty. An
1.30 cvs 3875: element which has no children or whose leaves are all empty is considered to
1.37 ! cvs 3876: be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
1.30 cvs 3877: optionally preceded by the <tt>NOT</tt> keyword. This condition can be
3878: associated only with <a href="#sectc4232">creation rules</a>.</p>
1.18 cvs 3879: </div>
1.1 cvs 3880:
1.18 cvs 3881: <div class="subsubsection">
1.37 ! cvs 3882: <h4><a name="sectd42146" id="sectd42146">Conditions on counters</a></h4>
1.1 cvs 3883:
1.30 cvs 3884: <p>Presentation rules can apply when the counter's value is one, is even or
3885: odd, is equal, greater than or less than a given value or falls in a range of
1.37 ! cvs 3886: values. This is particularly useful for creating header and footer boxes.
1.18 cvs 3887: These conditions can be associated only with <a href="#sectc4232">creation
3888: rules</a>.</p>
1.30 cvs 3889:
3890: <p>To compare the value of a counter to a given value, a comparison is given
1.1 cvs 3891: between parentheses. The comparison is composed of the counter name followed
3892: by an equals, greater than, or less than sign and the value to which the
1.37 ! cvs 3893: counter will be compared. A test for whether or not a counter's value falls
! 3894: in a range also appears within parentheses. In this case, the counter name is
1.18 cvs 3895: followed by the <tt>IN</tt> keyword and the range definition within brackets.
3896: The <tt>Even</tt>, <tt>Odd</tt> and <tt>One</tt> are used to test a counter's
3897: value and are followed by the counter name between parentheses.</p>
1.30 cvs 3898:
3899: <p>The list of possible conditions on counters is:</p>
1.18 cvs 3900: <dl>
1.30 cvs 3901: <dt><tt>Even (Counter)</tt></dt>
3902: <dd>the box is created only if the counter has an even value.</dd>
3903: <dt><tt>Odd (Counter)</tt></dt>
3904: <dd>the box is created only if the counter has an odd value.</dd>
3905: <dt><tt>One (Counter)</tt></dt>
3906: <dd>the box is created only the counter's value is 1.</dd>
3907: <dt><tt>NOT One (Counter)</tt></dt>
3908: <dd>the box is created, unless the counter's value is 1.</dd>
3909: <dt><tt>(Counter < Value)</tt></dt>
3910: <dd>the box is created only if the counter's value is less than
3911: Value.</dd>
3912: <dt><tt>(Counter > Value)</tt></dt>
3913: <dd>the box is created only if the counter's value is greater than
3914: Value.</dd>
3915: <dt><tt>(Counter = Value)</tt></dt>
3916: <dd>the box is created only if the counter's value is equal to Value.</dd>
3917: <dt><tt>NOT (Counter = Value)</tt></dt>
3918: <dd>the is created only if the counter's value is different than
3919: Value.</dd>
3920: <dt><tt>(Counter IN [MinValue..MaxValue])</tt></dt>
3921: <dd>the box is created only if the counter's value falls in the range
3922: bounded by MinValue and MaxValue (inclusive).</dd>
3923: <dt><tt>NOT (Counter IN [MinValue..MaxValue])</tt></dt>
3924: <dd>the box is created only if the value of the counter does not fall in
3925: the range bounded by MinValue and MaxValue (inclusive).</dd>
1.18 cvs 3926: </dl>
1.30 cvs 3927:
3928: <p><strong>Note:</strong> the <tt>NOT Even</tt> and <tt>NOT Odd</tt>
3929: conditions are syntactically correct but can be expressed more simply by
3930: <tt>Odd</tt> and <tt>Even</tt>, respectively.</p>
1.18 cvs 3931: </div>
3932: </div>
1.1 cvs 3933:
1.18 cvs 3934: <div class="subsection">
1.37 ! cvs 3935: <h3><a name="sectc4215" id="sectc4215">A presentation rule</a></h3>
1.1 cvs 3936:
1.34 cvs 3937: <p>A presentation rule defines either a presentation property or presentation
1.37 ! cvs 3938: function. The properties are:</p>
1.18 cvs 3939: <ul>
1.30 cvs 3940: <li>the position of the vertical and horizontal reference axes of the
3941: box,</li>
3942: <li>the position of the box in relation to other boxes,</li>
3943: <li>the height or width of the box, with overflow exceptions,</li>
3944: <li>the margins, padding and borders of the box,</li>
3945: <li>the characteristics of the lines contained in the box: linespacing,
1.35 cvs 3946: indentation of the first line, hyphenation,</li>
1.30 cvs 3947: <li>the conditions for breaking the box across pages,</li>
3948: <li>the characteristics of the characters contained in the box: size, font,
3949: style, underlining,</li>
3950: <li>the depth of the box among overlapping boxes (often called stacking
3951: order),</li>
3952: <li>the characteristics of graphic elements contained in the box: style and
3953: thickness of lines, fill pattern for closed objects,</li>
1.37 ! cvs 3954: <li>the colors in text, graphics, pictures, and symbols contained in the
! 3955: box are displayed or printed,</li>
1.30 cvs 3956: <li>for presentation boxes only, the contents of the box.</li>
3957: </ul>
3958:
1.37 ! cvs 3959: <p>The <a name="presfunct" id="presfunct">presentation functions</a> are:</p>
1.30 cvs 3960: <ul>
3961: <li>the creation of a presentation box</li>
3962: <li>the line-breaking or page-breaking style,</li>
3963: <li>the copying of another box,</li>
3964: <li>the display of the box background and border,</li>
3965: <li>the display of a background picture and its aspect.</li>
3966: </ul>
3967:
1.37 ! cvs 3968: <p>For each box and each view, every presentation property is defined once
! 3969: and only once, either explicitly or by the <a href="#sectc427">default
! 3970: rules</a>. In contrast, presentation functions are not obligatory and can
! 3971: appear many times for the same element. for example an element can create
! 3972: many presentation boxes. Another element may not use any presentation
1.18 cvs 3973: functions.</p>
1.30 cvs 3974:
1.34 cvs 3975: <p>Each rule defining a presentation property begins with a keyword followed
1.37 ! cvs 3976: by a colon. The keyword indicates the property which is the subject of the
! 3977: rule. After the keyword and the colon, the remainder of the rule varies. All
1.18 cvs 3978: rules are terminated by a semicolon.</p>
1.34 cvs 3979: <pre> Rule = Property ';' / PresFunc ';' .
3980: Property ='VertRef' ':' PositionHoriz /
1.6 cvs 3981: 'HorizRef' ':' PositionVert /
3982: 'VertPos' ':' VPos /
3983: 'HorizPos' ':' HPos /
3984: 'Height' ':' Dimension /
3985: 'Width' ':' Dimension /
3986: 'VertOverflow' ':' Boolean /
1.1 cvs 3987: 'HorizOverflow' ':' Boolean /
1.26 cvs 3988: 'MarginTop' ':' MarginWidth /
3989: 'MarginRight' ':' MarginWidth /
3990: 'MarginBottom' ':' MarginWidth /
3991: 'MarginLeft' ':' MarginWidth /
3992: 'PaddingTop' ':' PaddingWidth /
3993: 'PaddingRight' ':' PaddingWidth /
3994: 'PaddingBottom' ':' PaddingWidth /
3995: 'PaddingLeft' ':' PaddingWidth /
3996: 'BorderTopWidth' ':' BorderWidth /
3997: 'BorderRightWidth' ':' BorderWidth /
3998: 'BorderBottomWidth' ':' BorderWidth /
3999: 'BorderLeftWidth' ':' BorderWidth /
4000: 'BorderTopColor' ':' BorderColor /
4001: 'BorderRightColor' ':' BorderColor /
4002: 'BorderBottomColor' ':' BorderColor /
4003: 'BorderLeftColor' ':' BorderColor /
4004: 'BorderTopStyle' ':' BorderStyle /
4005: 'BorderRightStyle' ':' BorderStyle /
4006: 'BorderBottomStyle' ':' BorderStyle /
4007: 'BorderLeftStyle' ':' BorderStyle .
1.6 cvs 4008: 'LineSpacing' ':' DistanceInherit /
4009: 'Indent' ':' DistanceInherit /
4010: 'Adjust' ':' AdjustInherit /
4011: 'Hyphenate' ':' BoolInherit /
4012: 'PageBreak' ':' Boolean /
4013: 'LineBreak' ':' Boolean /
4014: 'InLine' ':' Boolean /
4015: 'NoBreak1' ':' AbsDist /
4016: 'NoBreak2' ':' AbsDist /
4017: 'Gather' ':' Boolean /
4018: 'Visibility' ':' NumberInherit /
4019: 'Size' ':' SizeInherit /
4020: 'Font' ':' NameInherit /
4021: 'Style' ':' StyleInherit /
1.23 cvs 4022: 'Weight' ':' WeightInherit /
1.6 cvs 4023: 'Underline' ':' UnderLineInherit /
4024: 'Thickness' ':' ThicknessInherit /
4025: 'Depth' ':' NumberInherit /
4026: 'LineStyle' ':' LineStyleInherit /
4027: 'LineWeight' ':' DistanceInherit /
4028: 'FillPattern' ':' NameInherit /
4029: 'Background' ':' NameInherit /
1.13 cvs 4030: 'Foreground' ':' NameInherit /
1.6 cvs 4031: 'Content' ':' VarConst .
1.1 cvs 4032: PresFunc = Creation '(' BoxID ')' /
4033: 'Line' /
4034: 'NoLine' /
4035: 'Page' '(' BoxID ')' /
1.13 cvs 4036: 'Copy' '(' BoxTypeToCopy ')' /
4037: 'ShowBox' /
1.18 cvs 4038: 'BackgroundPicture' ':' FileName /
4039: 'PictureMode' ':' PictMode /</pre>
4040: </div>
4041:
4042: <div class="subsection">
1.37 ! cvs 4043: <h3><a name="sectc4216" id="sectc4216">Box axes</a></h3>
1.18 cvs 4044:
1.30 cvs 4045: <p>The position of the middle axes <tt>VMiddle</tt> and <tt>HMiddle</tt> in
1.1 cvs 4046: relation to their box is always calculated automatically as a function of the
1.37 ! cvs 4047: height and width of the box and is not specified by the presentation rules.
! 4048: In the presentation schema, these middle axes are used only to position their
! 4049: box with respect to another by specifying the distance between the middle
! 4050: axis and an axis or a side of another box (see the <a
! 4051: href="#sectc4218">relative position</a>).</p>
! 4052:
! 4053: <p>The reference axes of a box are also used to position their box in
! 4054: relation to another, but in contrast to the middle axes, the presentation
! 4055: schema must make their position explicit, either in relation to a side or the
! 4056: middle axis of the box itself, or in relation to an axis of an enclosed
! 4057: box.</p>
1.30 cvs 4058:
1.37 ! cvs 4059: <p>Only boxes of base elements have predefined reference axes. For character
1.1 cvs 4060: string boxes, the horizontal reference axis is the baseline of the characters
4061: (the line which passes immediately under the upper-case letters, ignoring the
4062: letter Q) and the vertical reference axis is at the left edge of the first
1.18 cvs 4063: character of the string.</p>
1.30 cvs 4064:
1.37 ! cvs 4065: <p>The positions of a box's reference axes are defined by the
! 4066: <tt>VertRef</tt> and <tt>HorizRef</tt> rules which specify the <a
! 4067: href="#distance">distance</a> between the reference axis and an axis or
! 4068: parallel side of the same box or of an enclosed box.</p>
1.18 cvs 4069: <pre> 'VertRef' ':' PositionHoriz
4070: 'HorizRef' ':' PositionVert</pre>
1.30 cvs 4071:
1.18 cvs 4072: <blockquote class="example">
1.30 cvs 4073: <p><strong>Example:</strong></p>
4074:
4075: <p>If, in the structure schema for mathematical formulas, the fraction
4076: element is defined by</p>
4077: <pre>Fraction = BEGIN
1.1 cvs 4078: Numerator = Expression;
4079: Denominator = Expression;
1.18 cvs 4080: END;</pre>
1.30 cvs 4081:
4082: <p>then the horizontal reference axis of the fraction can be positioned on
4083: top of the denominator by the rule:</p>
4084: <pre>Fraction :
1.1 cvs 4085: BEGIN
4086: HorizRef : Enclosed Denominator . Top;
4087: ...
1.18 cvs 4088: END;</pre>
1.30 cvs 4089:
4090: <p>To put the horizontal reference axis of a column at its middle:</p>
4091: <pre>Column :
1.1 cvs 4092: BEGIN
4093: HorizRef : * . HMiddle;
4094: ...
1.18 cvs 4095: END;</pre>
4096: </blockquote>
4097: </div>
1.1 cvs 4098:
1.18 cvs 4099: <div class="subsection">
1.37 ! cvs 4100: <h3><a name="sectc4217" id="sectc4217">Distance units</a></h3>
1.1 cvs 4101:
1.30 cvs 4102: <p>Some distances and dimensions appear in many rules of a presentation
4103: schema, especially in position rules (<tt>VertPos, HorizPos</tt>), in extent
4104: rules for boxes (<tt>Height, Width</tt>), in rules defining lines
1.37 ! cvs 4105: (<tt>LineSpacing, Indent</tt>), in rules controlling pagination
! 4106: (<tt>NoBreak1, NoBreak2</tt>) and in rules specifying the thickness of
! 4107: strokes (<tt>LineWeight</tt>).</p>
1.30 cvs 4108:
4109: <p>In all these rules, the distance or extent can be expressed</p>
4110: <ul>
4111: <li>either in relative units, which depend on the size of the characters in
4112: the current font: height of the element's font or height of the letter
4113: 'x',</li>
1.37 ! cvs 4114: <li>or in absolute units: centimeter, millimeter, inch, typographer's
! 4115: point, pica or pixel.</li>
1.30 cvs 4116: </ul>
4117:
1.37 ! cvs 4118: <p>Units can be chosen freely. Thus, it is possible to use relative units in
1.30 cvs 4119: one rule, centimeters in the next rule, and typographer's points in
4120: another.</p>
4121:
1.37 ! cvs 4122: <p>Absolute units are used to set rigid rules for the appearance of
! 4123: documents. In contrast, relative units allow changes of scale. The editor
! 4124: lets the value of relative units be changed dynamically. Such changes affect
! 4125: every box using relative units simultaneously and in the same proportion.
! 4126: Changing the value of the relative units affects the size of the characters
! 4127: and graphical elements, and the size of the boxes and the distances between
! 4128: them.</p>
! 4129:
! 4130: <p>A <a name="distance" id="distance">distance</a> or extent is specified by
! 4131: a number, which may be followed by one or more spaces and a units keyword.
! 4132: When there is no units keyword, the number specifies the number of relative
! 4133: units, where a relative unit is the height of a character in the current font
! 4134: (an em). When the number is followed by a units keyword, the keyword
! 4135: indicates the type of absolute units:</p>
1.18 cvs 4136: <ul>
1.30 cvs 4137: <li><tt>em</tt>: height of the element's font,</li>
4138: <li><tt>ex</tt>: height of the letter 'x',</li>
4139: <li><tt>cm</tt>: centimeter,</li>
4140: <li><tt>mm</tt>: millimeter,</li>
4141: <li><tt>in</tt>: inch (1 in = 2.54 cm),</li>
4142: <li><tt>pt</tt>: point (1 pt = 1/72 in),</li>
4143: <li><tt>pc</tt>: pica (1 pc = 12 pt),</li>
4144: <li><tt>px</tt>: pixel.</li>
1.18 cvs 4145: </ul>
1.30 cvs 4146:
4147: <p>Whatever the chosen unit, relative or absolute, the number is not
1.37 ! cvs 4148: necessarily an integer and may be expressed in fixed point notation (using
! 4149: the American convention of a period to express the decimal point).</p>
1.30 cvs 4150:
1.37 ! cvs 4151: <p>If the distance appears in a presentation rule for a numeric attribute,
! 4152: the number can be replaced by the name of an attribute. In this case, the
! 4153: value of the attribute is used. Obviously, the attribute name cannot be
! 4154: followed by a decimal point and a fractional part, but it can be followed a
! 4155: units keyword. However, the choice of units is limited to em, ex, pt and
! 4156: px.</p>
1.18 cvs 4157: <pre> Distance = [ Sign ] AbsDist .
1.1 cvs 4158: Sign ='+' / '-' .
4159: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
4160: [ Unit ].
4161: IntegerOrAttr = IntegerPart / AttrID .
4162: IntegerPart = NUMBER .
4163: DecimalPart = NUMBER .
4164: Unit ='em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
1.18 cvs 4165: 'pc' / 'px' / '%' .</pre>
1.30 cvs 4166:
1.18 cvs 4167: <blockquote class="example">
1.30 cvs 4168: <p><strong>Example:</strong></p>
4169:
4170: <p>The following rules specify that a box has a height of 10.5 centimeters
4171: and a width of 5.3 ems:</p>
4172: <pre>Height : 10.5 cm;
1.18 cvs 4173: Width : 5.3;</pre>
4174: </blockquote>
4175: </div>
1.1 cvs 4176:
1.18 cvs 4177: <div class="subsection">
1.37 ! cvs 4178: <h3><a name="sectc4218" id="sectc4218">Relative positions</a></h3>
1.1 cvs 4179:
1.37 ! cvs 4180: <p>The positioning of boxes uses the eight axes and sides, the sides
! 4181: generally being used to define the juxtapositioning (vertical or horizontal)
! 4182: of boxes, the middle axes being used to define centering, and the reference
! 4183: axes being used for alignment.</p>
! 4184:
! 4185: <p>Two rules allow a box to be placed relative to other boxes. The
! 4186: <tt>VertPos</tt> rule positions the box vertically. The <tt>HorizPos</tt>
! 4187: rule positions the box horizontally. It is possible that a box's position
! 4188: could be entirely determined by other boxes positioned relative to it. In
! 4189: this case, the position is implicit and the word <tt>nil</tt> can be used to
! 4190: specify that no position rule is needed. Otherwise, an explicit rule must be
1.18 cvs 4191: given by indicating the axis or side which defines the position of the box,
4192: followed by an equals sign and the distance between between this axis or side
1.37 ! cvs 4193: and a parallel axis or side of another box, called the reference box. The box
1.18 cvs 4194: for which the rule is written will be positioned relative to the reference
4195: box.</p>
4196: <pre> 'VertPos' ':' VPos
1.6 cvs 4197: 'HorizPos' ':' HPos
4198: HPos = 'nil' / VertAxis '=' HorizPosition
4199: [ 'UserSpecified' ].
4200: VPos = 'nil' / HorizAxis '=' VertPosition
4201: [ 'UserSpecified' ].
1.1 cvs 4202: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
1.18 cvs 4203: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .</pre>
1.30 cvs 4204:
1.37 ! cvs 4205: <p>The reference box is an adjacent box: enclosing, enclosed or adjacent.
! 4206: When a rule is associated with a reference type attribute (and only in this
! 4207: case), it can be a box of the element designated by the attribute. The
! 4208: reference box can be either a presentation box previously defined in the
! 4209: <tt>BOXES</tt> section of the schema and created by a creation function, or
! 4210: the box associated with a structured element.</p>
! 4211:
! 4212: <p>The structural position of the reference box (relative to the box for
! 4213: which the rule is being written) is indicated by a keyword:
! 4214: <tt>Enclosing</tt>, <tt>Enclosed</tt>, or, for sibling boxes,
! 4215: <tt>Previous</tt> or <tt>Next</tt>. The reference attributes, or presentation
! 4216: boxes created by a reference attribute, the <tt>Referred</tt> keyword may be
! 4217: used to designate the element which the reference points to. The keyword
! 4218: <tt>Creator</tt> can be used in rules for presentation boxes to designate the
! 4219: box of the element which created the presentation box. Finally, the
! 4220: <tt>Root</tt> keyword can be used to designate the root of the document.</p>
1.30 cvs 4221:
4222: <p>When the keyword is ambiguous, it is followed by the name of an element
4223: type or presentation box which resolves the ambiguity (the <tt>Creator</tt>
1.37 ! cvs 4224: and <tt>Root</tt> keywords are never ambiguous). If this name is not given,
1.30 cvs 4225: then the first box encountered is used as the reference box. It is also
4226: possible to use just the name of an element type or presentation box without
1.37 ! cvs 4227: an initial keyword. In this case, a sibling having that name will be used. If
1.30 cvs 4228: the name is preceded by the keyword <tt>NOT</tt>, then the reference box will
4229: be the first box whose type is not the named one.</p>
4230:
4231: <p>In place of the box or type name, the keywords <tt>AnyElem</tt>,
1.18 cvs 4232: <tt>AnyBox</tt> and <tt>ElemWithAttr</tt> can be used, representing
1.17 cvs 4233: respectively, any structured element box, any presentation box, and the box
4234: corresponding to any structured element having a particular attribute,
4235: whatever its value; the name of this attribute must follow the keyword
1.18 cvs 4236: <tt>ElemWithAttr</tt>.</p>
1.30 cvs 4237:
4238: <p>A type name may be preceded by a star in order to resolve the ambiguity in
4239: the special case where the structure schema defines an <a
1.18 cvs 4240: href="#sectd3284">inclusion</a> without expansion (or with partial expansion)
1.37 ! cvs 4241: of the same type as an element of the scheme. For mark pairs (and only for <a
1.18 cvs 4242: href="#sectd3285">mark pairs</a>) the type name <em>must</em> be preceded by
4243: the <tt>First</tt> or <tt>Second</tt> keyword, which indicates which of the
1.37 ! cvs 4244: two marks of the pair should be used as the reference box.</p>
1.30 cvs 4245:
4246: <p>The star character ('<tt>*</tt>') used alone designates the box to which
1.37 ! cvs 4247: the rule applies (in this case, it is obviously useless to specify the type
! 4248: of the reference box).</p>
1.30 cvs 4249:
1.37 ! cvs 4250: <p>The keywords <tt>Enclosing</tt> and <tt>Enclosed</tt> can be used no
! 4251: matter what constructor defines the type to which the rule applies. When
! 4252: applied to the element which represents the entire document,
! 4253: <tt>Enclosing</tt> designates the window or page in which the document's
! 4254: image is displayed for the view to which the rule applies. A box or type name
! 4255: without a keyword is used for aggregate elements and designates another
! 4256: element of the same aggregate. It can also be used to designate a
! 4257: presentation or page layout box. The keywords <tt>Previous</tt> and
! 4258: <tt>Next</tt> are primarily used to denote list elements, but can also be
! 4259: used to denote elements of an aggregate.</p>
! 4260:
! 4261: <p>In the position rule, the structural position relative to the reference
! 4262: box is followed, after a period, by the name of an axis or side. The rule
! 4263: specifies its node's position as being some distance from this axis or side
! 4264: of the reference box. If this distance is zero, then the distance does not
! 4265: appear in the rule. Otherwise, it does appear as a positive or negative
1.30 cvs 4266: number (the sign is required for negative numbers). The sign takes into
4267: account the orientation of the coordinate axes: for top to bottom for the
1.37 ! cvs 4268: vertical axis and from left to right for the horizontal axis. Thus, a
1.30 cvs 4269: negative distance in a vertical position indicates that the side or axis
4270: specified in the rule is above the side or axis of the reference box.</p>
4271:
1.37 ! cvs 4272: <p>The distance can be followed by the <tt>UserSpecified</tt> keyword (even
! 4273: if the distance is nil and does not appear, the <tt>UserSpecified</tt>
! 4274: keyword can be used). It indicates that when the element to which the rule
! 4275: applies is being created, the editor will ask the user to specify the
! 4276: distance himself, using the mouse. In this case, the distance specified in
! 4277: the rule is a default distance which is suggested to the user but can be
! 4278: modified. The <tt>UserSpecified</tt> keyword can be used either in the
! 4279: vertical position rule, the horizontal position rule, or both.</p>
1.18 cvs 4280: <pre> VertPosition = Reference '.' HorizAxis [ Distance ] .
1.1 cvs 4281: HorizPosition = Reference '.' VertAxis [ Distance ] .
4282: Reference ='Enclosing' [ BoxTypeNot ] /
4283: 'Enclosed' [ BoxTypeNot ] /
4284: 'Previous' [ BoxTypeNot ] /
4285: 'Next' [ BoxTypeNot ] /
4286: 'Referred' [ BoxTypeNot ] /
4287: 'Creator' /
4288: 'Root' /
4289: '*' /
4290: BoxOrType .
4291: BoxOrType = BoxID /
4292: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 4293: 'AnyElem' / 'AnyBox' /
4294: 'ElemWithAttr' AttrID .
1.18 cvs 4295: BoxTypeNot = [ 'NOT' ] BoxOrType .</pre>
1.30 cvs 4296:
1.18 cvs 4297: <blockquote class="example">
1.30 cvs 4298: <p><strong>Example:</strong></p>
4299:
1.37 ! cvs 4300: <p>If a <a name="expos1" id="expos1">report</a> is defined by the following
! 4301: structure schema:</p>
1.30 cvs 4302: <pre>Report = BEGIN
1.6 cvs 4303: Title = Text;
4304: Summary = Text;
4305: Keywords = Text;
4306: ...
1.18 cvs 4307: END;</pre>
1.30 cvs 4308:
4309: <p>then the presentation schema could contain the rules:</p>
4310: <pre>Report : BEGIN
1.6 cvs 4311: VertPos : Top = Enclosing . Top;
4312: HorizPos : Left = Enclosing . Left;
4313: ...
1.18 cvs 4314: END;</pre>
1.30 cvs 4315:
1.37 ! cvs 4316: <p>These rules place the <a name="reportexample"
! 4317: id="reportexample">report</a> in the upper left corner of the enclosing
! 4318: box, which is the window in which the document is being edited.</p>
1.30 cvs 4319: <pre>Title : BEGIN
1.6 cvs 4320: VertPos : Top = Enclosing . Top + 1;
4321: HorizPos : VMiddle = Enclosing . VMiddle;
4322: ...
1.18 cvs 4323: END;</pre>
1.30 cvs 4324:
1.37 ! cvs 4325: <p>The top of the title is one line (a line has the height of the
! 4326: characters of the title) from the top of the report, which is also the top
! 4327: of the editing window. The title is centered horizontally in the window
! 4328: (see <a href="#posdim">figure</a>).</p>
1.30 cvs 4329: <pre>Summary : BEGIN
1.1 cvs 4330: VertPos : Top = Title . Bottom + 1.5;
4331: HorizPos : Left = Enclosing . Left + 2 cm;
4332: ...
1.18 cvs 4333: END;</pre>
1.30 cvs 4334:
1.37 ! cvs 4335: <p>The top of the summary is place a line and a half below the bottom of
! 4336: the title and is shifted two centimeters from the side of the window.</p>
1.18 cvs 4337: </blockquote>
1.30 cvs 4338:
1.18 cvs 4339: <blockquote class="example">
1.30 cvs 4340: <p><strong>Example:</strong></p>
4341:
1.37 ! cvs 4342: <p>Suppose there is a <a name="expos2" id="expos2">Design</a> logical
! 4343: structure which contains graphical elements:</p>
1.30 cvs 4344: <pre>Design = LIST OF (ElemGraph = GRAPHICS);</pre>
4345:
4346: <p>The following rules allow the user to freely choose the position of each
4347: element when it is created:</p>
4348: <pre>ElemGraph =
1.1 cvs 4349: BEGIN
4350: VertPos : Top = Enclosing . Top + 1 cm UserSpecified;
4351: HorizPos: Left = Enclosing . Left UserSpecified;
4352: ...
1.18 cvs 4353: END;</pre>
1.30 cvs 4354:
4355: <p>Thus, when a graphical element is created, its default placement is at
4356: the left of the window and 1 cm from the top, but the user can move it
4357: immediately, simply by moving the mouse.</p>
1.18 cvs 4358: </blockquote>
4359: </div>
1.1 cvs 4360:
1.18 cvs 4361: <div class="subsection">
1.37 ! cvs 4362: <h3><a name="sectc4219" id="sectc4219">Box extents</a></h3>
1.1 cvs 4363:
1.30 cvs 4364: <p>The extents (height and width) of each box are defined by the two rules
1.37 ! cvs 4365: <tt>Height</tt> and <tt>Width</tt>. There are three types of extents: fixed,
1.18 cvs 4366: relative, and elastic.</p>
1.1 cvs 4367:
1.18 cvs 4368: <div class="subsubsection">
1.37 ! cvs 4369: <h4><a name="sectd42191" id="sectd42191">Fixed extents</a></h4>
1.1 cvs 4370:
1.30 cvs 4371: <p>A fixed dimension sets the height or width of the box independently of all
1.37 ! cvs 4372: other boxes. It is expressed in <a href="#sectc4217">distance units</a>. The
1.18 cvs 4373: extent can be followed by the <tt>UserSpecified</tt> keyword which indicates
1.1 cvs 4374: that when the element to which the rule applies is being created, the editor
1.37 ! cvs 4375: will ask the user to specify the extent himself, using the mouse. In this
1.1 cvs 4376: case, the extent specified in the rule is a default extent which is suggested
1.37 ! cvs 4377: to the user but can be modified. The <tt>UserSpecified</tt> keyword can be
1.18 cvs 4378: used either in the <tt>Height</tt> rule, the <tt>Width</tt> rule, or both.</p>
1.30 cvs 4379:
4380: <p>A fixed extent rule can be ended by the <tt>Min</tt> keyword, which
4381: signifies that the indicated value is a minimum, and that, if the contents of
4382: the box require it, a larger extent is possible.</p>
1.18 cvs 4383: <pre> 'Height' ':' Dimension
1.1 cvs 4384: 'Width' ':' Dimension
4385: Dimension = AbsDist [ 'UserSpecified' ] [ 'Min' ] /
1.18 cvs 4386: ...</pre>
1.30 cvs 4387:
1.18 cvs 4388: <blockquote class="example">
1.30 cvs 4389: <p><strong>Example:</strong></p>
4390:
4391: <p>Continuing with the <a href="#expos2">previous example</a>, it is
4392: possible to allow the user to choose the size of each graphical element as
4393: it is created:</p>
4394: <pre>ElemGraph : BEGIN
1.6 cvs 4395: Width : 2 cm UserSpecified;
1.1 cvs 4396: Height : 1 cm UserSpecified;
4397: ...
1.18 cvs 4398: END;</pre>
1.30 cvs 4399:
4400: <p>Thus, when a graphical element is create, it is drawn by default with a
4401: width of 2 cm and a height of 1 cm, but the user is free to resize it
4402: immediately with the mouse.</p>
4403: <pre>Summary : BEGIN
1.1 cvs 4404: Height : 5 cm Min;
4405: ...
4406: END;
4407: Keywords : BEGIN
4408: VertPos : Top = Summary . Bottom;
4409: ...
1.18 cvs 4410: END;</pre>
4411: </blockquote>
4412: </div>
1.1 cvs 4413:
1.18 cvs 4414: <div class="subsubsection">
1.37 ! cvs 4415: <h4><a name="sectd42192" id="sectd42192">Relative extents</a></h4>
1.30 cvs 4416:
4417: <p>A relative extent determines the extent as a function of the extent of
4418: another box, just as a relative position places a box in relation to another.
4419: The reference box in an extent rule is designated using the same syntax as is
1.37 ! cvs 4420: used in a relative position rule. It is followed by a period and a
1.30 cvs 4421: <tt>Height</tt> or <tt>Width</tt> keyword, depending on the extent being
1.37 ! cvs 4422: referred to. Next comes the relation between the extent being defined and the
! 4423: extent of the reference box. This relation can be either a percentage or a
1.30 cvs 4424: difference.</p>
1.1 cvs 4425:
1.37 ! cvs 4426: <p>A percentage is indicated by a star (the multiplication symbol) followed
! 4427: by the numeric percentage value (which may be greater than or less than 100)
! 4428: and the percent (`%') character. A difference is simply indicated by a signed
1.18 cvs 4429: difference.</p>
1.30 cvs 4430:
4431: <p>If the rule appears in the presentation rules of a numeric attribute, the
1.1 cvs 4432: percentage value can be replaced by the name of the attribute. This attribute
1.37 ! cvs 4433: is then used as a percentage. The attribute can also be used as part of a <a
1.18 cvs 4434: href="#distance">difference</a>.</p>
1.30 cvs 4435:
4436: <p>Just as with a fixed extent, a relative extent rule can end with the
1.18 cvs 4437: <tt>Min</tt> keyword, which signifies that the extent is a minimum and that,
4438: if the contents of the box require it, a larger extent is possible.</p>
1.30 cvs 4439:
4440: <p>A special case of relative extent rules is:</p>
1.18 cvs 4441: <pre>Height : Enclosed . Height;</pre>
1.30 cvs 4442:
4443: <p>or</p>
1.18 cvs 4444: <pre>Width : Enclosed . Width;</pre>
1.30 cvs 4445:
4446: <p>which specifies that the box has a height (or width) such that it encloses
4447: all the boxes which it contains, excluding boxes having a rule
4448: <tt>VertOverflow: Yes;</tt> or <tt>HorizOverflow: Yes;</tt>.</p>
4449:
4450: <p><strong>Note:</strong> character strings (type <tt>TEXT_UNIT</tt>)
4451: generally must use the sum of the widths of the characters which compose them
4452: as their width, which is expressed by the rule:</p>
1.18 cvs 4453: <pre>TEXT_UNIT :
4454: Width : Enclosed . Width;</pre>
1.30 cvs 4455:
4456: <p>If this rule is not the default <tt>Width</tt> rule, it must be given
1.18 cvs 4457: explicitly in the <tt>RULES</tt> section which defines the presentation rules
4458: of the logical elements.</p>
4459: <pre> 'Height' ':' Extent
1.1 cvs 4460: 'Width' ':' Extent
4461: Extent = Reference '.' HeightWidth [ Relation ]
4462: [ 'Min' ] / ...
4463: HeightWidth ='Height' / 'Width' .
4464: Relation ='*' ExtentAttr '%' / Distance .
4465: ExtentAttr = ExtentVal / AttrID .
1.18 cvs 4466: ExtentVal = NUMBER .</pre>
1.30 cvs 4467:
1.18 cvs 4468: <blockquote class="example">
1.30 cvs 4469: <p><strong>Example:</strong></p>
4470:
4471: <p>Completing the <a href="#expos1">above example</a>, it is possible to
4472: specify that the report takes its width from the editing window and its
4473: height from the size of its contents (this can obviously be greater than
4474: that of the window):</p>
4475: <pre>Report : BEGIN
1.1 cvs 4476: Width : Enclosing . Width;
4477: Height : Enclosed . Height;
4478: ...
1.18 cvs 4479: END;</pre>
1.30 cvs 4480:
4481: <p>Then, the following rules make the title occupy 60% of the width of the
4482: report (which is that of the window) and is broken into centered lines of
4483: this width (see the <a href="#sectc4222"><tt>Line</tt> rule</a>).</p>
4484: <pre>Title : BEGIN
1.1 cvs 4485: Width : Enclosing . Width * 60%;
4486: Height : Enclosed . Height;
4487: Line;
4488: Adjust : VMiddle;
4489: ...
1.18 cvs 4490: END;</pre>
1.30 cvs 4491:
4492: <p>The summary occupy the entire width of the window, with the exception of
4493: a 2 cm margin reserved by the horizontal position rule:</p>
4494: <pre>Summary : BEGIN
1.1 cvs 4495: Width : Enclosing . Width - 2 cm;
4496: Height : Enclosed . Height;
4497: ...
1.18 cvs 4498: END;</pre>
4499:
1.37 ! cvs 4500: <p>This set of rules, plus the <a href="#reportexample">position rules
! 4501: given above</a>, produce the layout of boxes shown in the following<a
1.30 cvs 4502: href="#posdim">figure</a>.</p>
4503:
4504: <div class="figure">
1.37 ! cvs 4505: <hr />
1.30 cvs 4506: <pre>-------------------------------------------------------------
1.1 cvs 4507: | Window and Report ^ |
4508: | | 1 line |
4509: | v |
4510: | ------------------------------------- |
4511: | | | |
4512: : 20% : Title : 20% :
1.30 cvs 4513: :<--------->: :<--------->:
1.1 cvs 4514: : : 60% : :
1.30 cvs 4515: : :<--------------------------------->: :
1.1 cvs 4516: | | | |
4517: | ------------------------------------- |
4518: | ^ |
4519: | | 1.5 line |
4520: | | |
4521: | v |
4522: | ---------------------------------------------------|
4523: | 2 cm | |
1.30 cvs 4524: |<------>| Summary |
1.18 cvs 4525: : : :</pre>
1.19 cvs 4526:
1.37 ! cvs 4527: <p align="center"><em><a name="posdim" id="posdim">Box position and
1.30 cvs 4528: extent</a><em></em></em></p>
1.37 ! cvs 4529: <hr />
1.30 cvs 4530: </div>
1.18 cvs 4531: </blockquote>
4532: </div>
1.1 cvs 4533:
1.18 cvs 4534: <div class="subsubsection">
1.37 ! cvs 4535: <h4><a name="sectd42193" id="sectd42193">Elastic extents</a></h4>
1.1 cvs 4536:
1.37 ! cvs 4537: <p>The last type of extent is the elastic extent. Either one or both extents
! 4538: can be elastic. A box has an elastic extent when two opposite sides are
1.30 cvs 4539: linked by distance constraints to two sides or axes of other boxes.</p>
4540:
4541: <p>One of the sides of the elastic box is linked by a position rule
1.37 ! cvs 4542: (<tt>VertPos</tt> or <tt>HorizPos</tt>) to a neighboring box. The other side
1.18 cvs 4543: is link to another box by a <tt>Height</tt> or <tt>Width</tt> rule, which
1.37 ! cvs 4544: takes the same form as the position rule. For the elastic box itself, the
1.1 cvs 4545: notions of sides (left or right, top or bottom) are fuzzy, since the movement
4546: of either one of the two reference boxes can, for example, make the left side
1.37 ! cvs 4547: of the elastic box move to the right of its right side. This is not
! 4548: important. The only requirement is that the two sides of the elastic box used
1.18 cvs 4549: in the position and extent rule are opposite sides of the box.</p>
4550: <pre> 'Height' ':' Extent
1.6 cvs 4551: 'Width' ':' Extent
1.18 cvs 4552: Extent = HPos / VPos / ...</pre>
1.30 cvs 4553:
1.18 cvs 4554: <blockquote class="example">
1.30 cvs 4555: <p><strong>Example:</strong></p>
4556:
4557: <p>Suppose we want to draw an elastic arrow or line between the middle of
1.37 ! cvs 4558: the bottom side of box A and the upper left corner of box B. To do this, we
1.30 cvs 4559: would define a graphics box whose upper left corner coincides with the
4560: middle of the bottom side of A (a position rule) and whose lower right
4561: corner coincides with with the upper left corner of B (dimension rules):</p>
4562: <pre>LinkedBox :
1.1 cvs 4563: BEGIN
1.6 cvs 4564: VertPos : Top = A .Bottom;
1.1 cvs 4565: HorizPos : Left = A . VMiddle;
1.6 cvs 4566: Height : Bottom = B . Top;
4567: Width : Right = B . Left;
1.18 cvs 4568: END;</pre>
4569: </blockquote>
1.30 cvs 4570:
1.18 cvs 4571: <blockquote class="example">
1.30 cvs 4572: <p><strong>Example:</strong></p>
4573:
4574: <p>The element SectionTitle creates a presentation box called SectionNum
1.37 ! cvs 4575: which contains the number of the section. Suppose we want to align the
! 4576: SectionNum and SectionTitle horizontally, have the SectionNum take its
! 4577: width from its contents (the section number), have the SectionTitle box
! 4578: begin 0.5 cm to the right of the SectionNum box and end at the right edge
! 4579: of its enclosing box. This would make the SectionTitle box elastic, since
! 4580: its width is defined by the position of its left and right sides. The
! 4581: following rules produce this effect:</p>
1.30 cvs 4582: <pre>SectionNum :
1.1 cvs 4583: BEGIN
4584: HorizPos : Left = Enclosing . Left;
4585: Width : Enclosed . Width;
4586: ...
4587: END;
4588:
4589: SectionTitle :
4590: BEGIN
4591: HorizPos : Left = SectionNum . Right + 0.5 cm;
4592: Width : Right = Enclosing . Right;
4593: ...
1.18 cvs 4594: END;</pre>
4595: </blockquote>
4596: </div>
4597: </div>
1.1 cvs 4598:
1.18 cvs 4599: <div class="subsection">
1.37 ! cvs 4600: <h3><a name="sectc4220" id="sectc4220">Overflow</a></h3>
1.1 cvs 4601:
1.30 cvs 4602: <p>A boxes corresponding to a structural element normally contain all boxes
1.37 ! cvs 4603: corresponding to the elements of its subtree. However, in some cases, it
1.1 cvs 4604: could be necessary to allow a box to jut out from its parent box. Two
4605: presentation rules indicate that such an overflow is allowed, one for
1.18 cvs 4606: horizontal overflow, one for vertical overflow.</p>
1.30 cvs 4607:
4608: <p>Each of these rules is expressed by a keyword followed by a colon and the
1.18 cvs 4609: keyword <tt>Yes</tt> or <tt>No</tt>.</p>
4610: <pre> 'VertOverflow' ':' Boolean /
1.1 cvs 4611: 'HorizOverflow' ':' Boolean .
1.18 cvs 4612: Boolean = 'Yes' / 'No' .</pre>
4613: </div>
1.1 cvs 4614:
1.30 cvs 4615: <p>@@@@@ ******</p>
4616:
1.26 cvs 4617: <p>Explain Margin, Padding and Border. Refer to CSS2.</p>
4618: <pre> 'MarginTop' ':' MarginWidth /
4619: 'MarginRight' ':' MarginWidth /
4620: 'MarginBottom' ':' MarginWidth /
4621: 'MarginLeft' ':' MarginWidth /
4622: 'PaddingTop' ':' PaddingWidth /
4623: 'PaddingRight' ':' PaddingWidth /
4624: 'PaddingBottom' ':' PaddingWidth /
4625: 'PaddingLeft' ':' PaddingWidth /
4626: 'BorderTopWidth' ':' BorderWidth /
4627: 'BorderRightWidth' ':' BorderWidth /
4628: 'BorderBottomWidth' ':' BorderWidth /
4629: 'BorderLeftWidth' ':' BorderWidth /
4630: 'BorderTopColor' ':' BorderColor /
4631: 'BorderRightColor' ':' BorderColor /
4632: 'BorderBottomColor' ':' BorderColor /
4633: 'BorderLeftColor' ':' BorderColor /
4634: 'BorderTopStyle' ':' BorderStyle /
4635: 'BorderRightStyle' ':' BorderStyle /
4636: 'BorderBottomStyle' ':' BorderStyle /
4637: 'BorderLeftStyle' ':' BorderStyle .
4638:
4639: MarginWidth = InheritParent / 'Auto' / Distance .
4640: PaddingWidth = InheritParent / Distance .
4641: BorderWidth = InheritParent / 'Thin' / 'Medium' / 'Thick' / Distance .
4642: BorderColor = InheritParent / 'Transparent' / 'Foreground' /
4643: ColorName .
4644: BorderStyle = InheritParent /
4645: 'None' / 'Hidden' / 'Dotted' / 'Dashed' / 'Solid' /
4646: 'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
1.27 cvs 4647: InheritParent = 'Enclosing' '=' / 'Creator' '=' .
1.26 cvs 4648: ColorName = NAME .</pre>
1.30 cvs 4649:
4650: <p>@@@@@ ******</p>
1.26 cvs 4651:
1.18 cvs 4652: <div class="subsection">
1.37 ! cvs 4653: <h3><a name="sectc4221" id="sectc4221">Inheritance</a></h3>
1.1 cvs 4654:
1.37 ! cvs 4655: <p>A presentation property can be defined by reference to the same property
! 4656: of another box in the tree of boxes. These structural links are expressed by
! 4657: kinship. The reference box can be that of the element immediately above in
1.18 cvs 4658: the structure (<tt>Enclosing</tt>), two levels above (<tt>GrandFather</tt>),
4659: immediately below (<tt>Enclosed</tt>) or immediately before
1.37 ! cvs 4660: (<tt>Previous</tt>). In the case of a presentation box, and only in that
1.1 cvs 4661: case, the reference box may be the element which created the presentation box
1.18 cvs 4662: (<tt>Creator</tt>).</p>
1.30 cvs 4663:
4664: <p>Kinship is expressed in terms of the logical structure of the document and
1.37 ! cvs 4665: not in terms of the tree of boxes. The presentation box cannot transmit any
1.34 cvs 4666: of their properties by inheritance; only structured element boxes can do so.
1.37 ! cvs 4667: As an example, consider an element B which follows an element A in the
! 4668: logical structure. The element B creates a presentation box P in front of
! 4669: itself, using the <tt>CreateBefore</tt> rule (see the <a
! 4670: href="#sectc4232">creation rules</a>). If element B's box inherits its
! 4671: character style using the <tt>Previous</tt> kinship operation, it gets its
! 4672: character style from A's box, not from P's box. Inheritance works differently
! 4673: for positions and extents, which can refer to presentation boxes.</p>
1.30 cvs 4674:
1.34 cvs 4675: <p>The inherited property value can be the same as that of the reference box.
1.37 ! cvs 4676: This is indicated by an equals sign. However, for numeric properties, a
1.1 cvs 4677: different value can be obtained by adding or subtracting a number from the
1.37 ! cvs 4678: reference box's property value. Addition is indicated by a plus sign before
! 4679: the number, while subtraction is specified with a minus sign. The value of a
1.34 cvs 4680: property can also be given a maximum (if the sign is a plus) or minimum (if
1.18 cvs 4681: the sign is a minus).</p>
1.30 cvs 4682:
4683: <p>If the rule is being applied to a numeric attribute, the number to add or
1.37 ! cvs 4684: subtract can be replaced by the attribute name. The value of a maximum or
! 4685: minimum may also be replaced by an attribute name. In these cases, the value
1.18 cvs 4686: of the attribute is used.</p>
4687: <pre> Inheritance = Kinship InheritedValue .
1.6 cvs 4688: Kinship ='Enclosing' / 'GrandFather' / 'Enclosed' /
4689: 'Previous' / 'Creator' .
1.1 cvs 4690: InheritedValue ='+' PosIntAttr [ 'Max' maximumA ] /
1.6 cvs 4691: '-' NegIntAttr [ 'Min' minimumA ] /
4692: '=' .
4693: PosIntAttr = PosInt / AttrID .
4694: PosInt = NUMBER .
4695: NegIntAttr = NegInt / AttrID .
4696: NegInt = NUMBER .
4697: maximumA = maximum / AttrID .
4698: maximum = NUMBER .
4699: minimumA = minimum / AttrID .
1.18 cvs 4700: minimum = NUMBER .</pre>
1.30 cvs 4701:
1.36 cvs 4702: <p>The properties which can be obtained by inheritance are hyphenation,
4703: interline spacing, character font (font family), font style, font size,
4704: visibility, indentation, underlining, alignment of text, stacking order of
4705: objects, the style and thickness of lines, fill pattern and the colors of
1.18 cvs 4706: lines and characters.</p>
4707: </div>
1.1 cvs 4708:
1.18 cvs 4709: <div class="subsection">
1.37 ! cvs 4710: <h3><a name="sectc4222" id="sectc4222">Line breaking</a></h3>
1.1 cvs 4711:
1.30 cvs 4712: <p>The <tt>Line</tt> rule specifies that the contents of the box should be
4713: broken into lines: the boxes included in the box to which this rule is
4714: attached are displayed one after the other, from left to right, with their
1.37 ! cvs 4715: horizontal reference axes aligned so that they form a series of lines. The
1.30 cvs 4716: length of these lines is equal to the width of the box to which the
4717: <tt>Line</tt> rule is attached.</p>
4718:
4719: <p>When an included box overflows the current line, it is either carried
1.37 ! cvs 4720: forward to the next line, cur, or left the way it is. The <a
1.18 cvs 4721: href="#sectc4223"><tt>LineBreak</tt> rule</a> is used to allow or prevent the
1.37 ! cvs 4722: breaking of included boxes. If the included box is not breakable but is
! 4723: longer than the space remaining on the line, it is left as is. When a
1.1 cvs 4724: character string box is breakable, the line is broken between words or, if
1.37 ! cvs 4725: necessary, by <a href="#sectd42225">hyphenating a word</a>. When a compound
! 4726: box is breakable, the box is transparent in regard to line breaking. The
! 4727: boxes included in the compound box are treated just like included boxes which
! 4728: have the <tt>LineBreak</tt> rule. Thus, it is possible to traverse a complete
1.18 cvs 4729: subtree of boxes to line break the text leaves of a complex structure.</p>
1.30 cvs 4730:
4731: <p>The relative position rules of the included boxes are ignored, since the
4732: boxes will be placed according to the line breaking rules.</p>
4733:
1.37 ! cvs 4734: <p>The <tt>Line</tt> rule does not have a parameter. The characteristics of
! 4735: the lines that will be constructed are determined by the
! 4736: <tt>LineSpacing</tt>, <tt>Indent</tt>, <tt>Adjust</tt>, and
! 4737: <tt>Hyphenate</tt> rules. Moreover, the <a
! 4738: href="#insectd42226"><tt>Inline</tt> rule</a> permits the exclusion of
1.36 cvs 4739: certain elements from the line breaking process.</p>
1.30 cvs 4740:
4741: <p>When the <tt>Line</tt> rule appears in the rules sequence of a non-primary
1.37 ! cvs 4742: view, it applies only to that view, but when the <tt>Line</tt> rule appears
! 4743: in the rules sequence of the primary view, it also applies to the other views
! 4744: by default, except for those views which explicitly invoke the
! 4745: <tt>NoLine</tt> rule. Thus, the <tt>NoLine</tt> rule can be used in a
! 4746: non-primary view to override the primary view's <tt>Line</tt> rule. The
! 4747: <tt>NoLine</tt> rule must not be used with the primary view because the
! 4748: absence of the <tt>Line</tt> rule has the same effect. Like the <tt>Line</tt>
! 4749: rule, the <tt>NoLine</tt> rule does not take any parameters.</p>
1.18 cvs 4750: <pre> 'Line'
4751: 'NoLine'</pre>
4752:
4753: <div class="subsubsection">
1.37 ! cvs 4754: <h4><a name="sectd42221" id="sectd42221">Line spacing</a></h4>
1.18 cvs 4755:
1.30 cvs 4756: <p>The <tt>LineSpacing</tt> rule defines the line spacing to be used in the
1.37 ! cvs 4757: line breaking process. The line spacing is the distance between the baselines
1.1 cvs 4758: (horizontal reference axis) of the successive lines produced by the
1.37 ! cvs 4759: <tt>Line</tt> rule. The value of the line spacing can be specified as a
! 4760: constant or by inheritance. It is expressed in any of the available <a
1.18 cvs 4761: href="#sectc4217">distance units</a>.</p>
1.30 cvs 4762:
4763: <p>Inheritance allows the value to be obtained from a relative in the
4764: structure tree, either without change (an equals sign appears after the
4765: inheritance keyword), with a positive difference (a plus sign), or a negative
1.37 ! cvs 4766: difference (a minus sign). When the rule uses a difference, the value of the
1.30 cvs 4767: difference follows the sign and is expressed as a <a
4768: href="#sectc4217">distance</a>.</p>
1.18 cvs 4769: <pre> 'LineSpacing' ':' DistOrInherit
1.6 cvs 4770: DistOrInherit = Kinship InheritedDist / Distance .
1.18 cvs 4771: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .</pre>
1.30 cvs 4772:
4773: <p>When the line spacing value (or its difference from another element) is
1.37 ! cvs 4774: expressed in relative units, it changes with the size of the characters.
! 4775: Thus, when a larger font is chosen for a part of the document, the line
! 4776: spacing of that part expands proportionally. In contrast, when the line
! 4777: spacing value is expressed in absolute units (centimeters, inches,
! 4778: typographer's points), it is independent of the characters, which permits the
! 4779: maintenance of a consistent line spacing, whatever the character font. Either
! 4780: approach can be taken, depending on the desired effect.</p>
1.18 cvs 4781: </div>
1.1 cvs 4782:
1.18 cvs 4783: <div class="subsubsection">
1.37 ! cvs 4784: <h4><a name="sectd42222" id="sectd42222">First line indentation</a></h4>
1.1 cvs 4785:
1.30 cvs 4786: <p>The <tt>Indent</tt> rule is used to specify the indentation of the first
4787: line of the elements broken into lines by the <tt>Line</tt> function. The
1.1 cvs 4788: indentation determines how far the first line of the element is shifted with
1.37 ! cvs 4789: respect to the other lines of the same element. It can be specified as a
! 4790: constant or by inheritance. The constant value is a positive integer (shifted
1.1 cvs 4791: to the right; the sign is optional), a negative integer (shifted to the left)
1.37 ! cvs 4792: or zero (no shift). All available <a href="#sectc4217">units</a> can be
1.18 cvs 4793: used.</p>
1.30 cvs 4794:
4795: <p>Indentation can be defined for any box, regardless of whether the box is
4796: line broken, and transmitted by inheritance to elements that are line broken.
4797: The size of the indentation is specified in the same manner as the <a
1.18 cvs 4798: href="#sectd42221">line spacing</a>.</p>
4799: <pre> 'Indent' ':' DistOrInherit</pre>
4800: </div>
1.1 cvs 4801:
1.18 cvs 4802: <div class="subsubsection">
1.37 ! cvs 4803: <h4><a name="sectd42223" id="sectd42223">Alignment</a></h4>
1.1 cvs 4804:
1.30 cvs 4805: <p>The alignment style of the lines constructed during line breaking is
1.37 ! cvs 4806: defined by the <tt>Adjust</tt> rule. The alignment value can be a constant or
! 4807: inherited. A constant value is specified by a keyword:</p>
1.18 cvs 4808: <ul>
1.30 cvs 4809: <li><tt>Left</tt>: at the left edge,</li>
4810: <li><tt>Right</tt>: at the right edge,</li>
4811: <li><tt>VMiddle</tt>: centered</li>
1.35 cvs 4812: <li><tt>Justify</tt>: justified</li>
1.30 cvs 4813: <li><tt>LeftWithDots</tt>: at the left edge with a dotted line filling out
4814: the last line up to the right edge of the line breaking box.</li>
1.18 cvs 4815: </ul>
1.30 cvs 4816:
1.37 ! cvs 4817: <p>An inherited value can only be the same as that of the reference box and
! 4818: is specified by a kinship keyword followed by an equals sign.</p>
1.18 cvs 4819: <pre> 'Adjust' ':' AlignOrInherit
1.1 cvs 4820: AlignOrInherit = Kinship '=' / Alignment .
1.35 cvs 4821: Alignment = 'Left' / 'Right' / 'VMiddle' / 'Justify' /
1.18 cvs 4822: 'LeftWithDots' .</pre>
4823: </div>
1.1 cvs 4824:
1.18 cvs 4825: <div class="subsubsection">
1.37 ! cvs 4826: <h4><a name="sectd42225" id="sectd42225">Hyphenation</a></h4>
1.18 cvs 4827:
1.37 ! cvs 4828: <p>The <tt>Hyphenate</tt> rule indicates whether or not words should be
! 4829: broken by hyphenation at the end of lines. It affects the lines produced by
! 4830: the <tt>Line</tt> rule and contained in the box carrying the
! 4831: <tt>Hyphenate</tt> rule.</p>
1.30 cvs 4832:
1.34 cvs 4833: <p>The hyphenation property takes a boolean value, which can be either
1.37 ! cvs 4834: constant or inherited. A constant boolean value is expressed by either the
! 4835: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 4836: same as that of the reference box and is specified by a kinship keyword
1.18 cvs 4837: followed by an equals sign.</p>
4838: <pre> 'Hyphenate' ':' BoolInherit
1.1 cvs 4839: BoolInherit = Boolean / Kinship '=' .
1.18 cvs 4840: Boolean = 'Yes' / 'No' .</pre>
4841: </div>
4842:
4843: <div class="subsubsection">
1.37 ! cvs 4844: <h4><a name="sectd42226" id="sectd42226">Avoiding line breaking</a></h4>
1.18 cvs 4845:
1.37 ! cvs 4846: <p>The <tt>InLine</tt> rule is used to specify that a box that would
! 4847: otherwise participate in line breaking asked for by the <tt>Line</tt> rule of
! 4848: an enclosing box, instead avoids the line breaking process and positions
! 4849: itself according to the <tt>HorizPos</tt> and <tt>VertPos</tt> rules that
! 4850: apply to it. When the <tt>InLine</tt> rule applies to a box which would not
! 4851: be line broken, it has no effect.</p>
1.30 cvs 4852:
4853: <p>The rule is expressed by the <tt>InLine</tt> keyword followed by a colon
4854: and the keyword <tt>Yes</tt>, if the box should participate in line breaking,
1.37 ! cvs 4855: or the keyword <tt>No</tt>, if it should not. This is the only form possible:
! 4856: this rule cannot be inherited. Moreover, it can only appear in the rules of
1.1 cvs 4857: the primary view and applies to all views defined in the presentation
1.18 cvs 4858: schema.</p>
4859: <pre> 'InLine' ':' Boolean .
4860: Boolean = 'Yes' / 'No' .</pre>
1.30 cvs 4861:
1.18 cvs 4862: <blockquote class="example">
1.30 cvs 4863: <p><strong>Example:</strong></p>
4864:
4865: <p>Suppose the structure schema defines a logical attribute called
1.37 ! cvs 4866: <tt>New</tt> which is used to identify the passages in a document which
! 4867: were recently modified. It would be nice to have the presentation schema
! 4868: make a bar appear in the left margin next to each passage having the
! 4869: <tt>New</tt> attribute. A new passage can be an entire element, such as a
! 4870: paragraph or section, or it can be some words in the middle of a paragraph.
! 4871: To produce the desired effect, the <tt>New</tt> attribute is given a
! 4872: creation rule which generates a <tt>VerticalBar</tt> presentation box.</p>
1.30 cvs 4873:
4874: <p>When the <tt>New</tt> attribute is attached to a character string which
4875: is inside a line broken element (inside a paragraph, for example), the bar
4876: is one of the elements which participates in line breaking and it is placed
4877: normally in the current line, at the end of the character string which has
1.37 ! cvs 4878: the attribute. To avoid this, the <tt>InLine</tt> rule is used in the
1.30 cvs 4879: following way:</p>
4880: <pre>BOXES
1.1 cvs 4881: VerticalBar:
4882: BEGIN
4883: Content: Graphics 'l';
4884: HorizPos: Left = Root . Left;
4885: VertPos: Top = Creator . Top;
4886: Height: Bottom = Creator . Bottom;
4887: Width: 1 pt;
4888: InLine: No;
4889: ...
4890: END;
4891: ...
4892: ATTRIBUTES
4893: Nouveau:
4894: BEGIN
4895: CreateAfter(VerticalBar);
1.18 cvs 4896: END;</pre>
4897: </blockquote>
4898: </div>
4899: </div>
1.1 cvs 4900:
1.18 cvs 4901: <div class="subsection">
1.37 ! cvs 4902: <h3><a name="sectc4223" id="sectc4223">Page breaking and line breaking
! 4903: conditions</a></h3>
1.1 cvs 4904:
1.30 cvs 4905: <p>Pages are constructed by the editor in accordance with the model specified
1.37 ! cvs 4906: by a <a href="#sectc4233"><tt>Page</tt> rule</a>. The page model describes
1.30 cvs 4907: only the composition of the pages but does not give any rules for breaking
1.37 ! cvs 4908: different element types across pages. Now, it is possible that certain
! 4909: elements must not be cut by page breaks, while others can be cut anywhere.
! 4910: The <tt>PageBreak</tt>, <tt>NoBreak1</tt>, and <tt>NoBreak2</tt> rules are
! 4911: used to specify the conditions under which each element type can be cut.</p>
1.30 cvs 4912:
4913: <p>The <tt>PageBreak</tt> rule is used to indicate whether or not the box can
1.37 ! cvs 4914: be cut during the construction of pages. If cutting is authorized, the box
! 4915: can be cut, with one part appearing at the bottom of a page and the other
! 4916: part appearing at the top of the next page. The rule is formed by the
1.18 cvs 4917: <tt>PageBreak</tt> keyword followed by a colon and a constant boolean value
1.37 ! cvs 4918: (<tt>Yes</tt> or <tt>No</tt>). This is the only form possible: this rule
! 4919: cannot be inherited. Moreover, it can only appear in the rules of the primary
1.18 cvs 4920: view and applies to all views defined in the presentation schema.</p>
1.30 cvs 4921:
4922: <p>Whether objects can be cut by line breaks can be controlled in a similar
1.37 ! cvs 4923: way using the <tt>LineBreak</tt> rule. This rule allows the specification of
! 4924: whether or not the box can be cut during the construction of lines. If
1.1 cvs 4925: cutting is authorized, the box can be cut, with one part appearing at the end
1.37 ! cvs 4926: of a line and the other part appearing at the beginning of the next line. The
1.18 cvs 4927: rule is formed by the <tt>LineBreak</tt> keyword followed by a colon and a
1.37 ! cvs 4928: constant boolean value (<tt>Yes</tt> or <tt>No</tt>). This is the only form
! 4929: possible: this rule cannot be inherited. Moreover, it can only appear in the
! 4930: rules of the primary view and applies to all views defined in the
! 4931: presentation schema.</p>
1.18 cvs 4932: <pre> 'PageBreak' ':' Boolean .
1.1 cvs 4933: 'LineBreak' ':' Boolean .
1.18 cvs 4934: Boolean = 'Yes' / 'No' .</pre>
1.30 cvs 4935:
4936: <p>When a box can be cut by a page break, it is possible that a page break
4937: will fall an inappropriate spot, creating, for example, a widow or orphan, or
1.37 ! cvs 4938: separating the title of a section from the first paragraph of the section.
! 4939: The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules are used to avoid this.
! 4940: They specify that the box of the element to which they apply cannot be cut
! 4941: within a certain zone at the top (<tt>NoBreak1</tt> rule) or at the bottom
! 4942: (<tt>NoBreak2</tt> rule). These two rules specify the height of the zones in
1.18 cvs 4943: which page breaks are prohibited.</p>
1.30 cvs 4944:
4945: <p>The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules give the height of the
1.37 ! cvs 4946: zone in which page breaking is prohibited. The height is given as a constant
1.30 cvs 4947: value using any of the <a href="#sectc4217">available units</a>, absolute or
1.37 ! cvs 4948: relative. The value may not be inherited.</p>
1.18 cvs 4949: <pre> 'NoBreak1' ':' AbsDist .
4950: 'NoBreak2' ':' AbsDist .</pre>
1.30 cvs 4951:
1.18 cvs 4952: <blockquote class="example">
1.30 cvs 4953: <p><strong>Example:</strong></p>
4954:
4955: <p>The following rules prevent widows and orphans in a paragraph:</p>
4956: <pre>Paragraph :
1.1 cvs 4957: BEGIN
4958: NoBreak1 : 2;
4959: NoBreak2 : 2;
1.18 cvs 4960: END;</pre>
1.30 cvs 4961:
1.37 ! cvs 4962: <p>This rule prevents a section title from becoming separated from the
! 4963: first paragraph of the section by prohibiting page breaks at the beginning
! 4964: of the section rule:</p>
1.30 cvs 4965: <pre>Section :
1.18 cvs 4966: NoBreak1 : 1.5 cm;</pre>
1.30 cvs 4967:
4968: <p>Finally, this rule prevents a figure from being page broken in any
4969: way:</p>
4970: <pre>Figure :
1.18 cvs 4971: PageBreak : No;</pre>
4972: </blockquote>
1.30 cvs 4973:
4974: <p>The Thot editor constructs the document images displayed on the screen
1.37 ! cvs 4975: dynamically. As the user moves in the document or makes the document scroll
1.1 cvs 4976: in a window, the editor constructs the image to be displayed in little bits,
1.37 ! cvs 4977: filling the gaps which are produced in the course of these operations. It
1.1 cvs 4978: stops filling in the image when an element reaches the edge of the window in
1.37 ! cvs 4979: which the gap appears. If the appearance of the document is complex, it is
1.1 cvs 4980: possible that the image in incomplete, even though the edge of the window was
1.37 ! cvs 4981: reached. For example, an element might need to be presented to the side of
! 4982: the last element displayed, but its image was not constructed. The user will
1.1 cvs 4983: not know whether the element is really absent or if its image has simply not
1.18 cvs 4984: been constructed.</p>
1.30 cvs 4985:
1.37 ! cvs 4986: <p>The <tt>Gather</tt> rule is used to remedy this problem. When the rule
1.18 cvs 4987: <tt>Gather : Yes;</tt> is associated with an element type, the image of such
4988: elements is constructed as a block by the editor: it is never split up.</p>
1.30 cvs 4989:
4990: <p>The <tt>Gather</tt> rule may not appear in the <a href="#sectc427">default
1.37 ! cvs 4991: rules</a>. Elements which do not have the <tt>Gather</tt> rule are considered
! 4992: susceptible to being split up during display. Thus, it is not necessary to
1.18 cvs 4993: use the <tt>Gather : No;</tt> form. This rule must be used prudently and only
1.37 ! cvs 4994: for those elements which truly need it. If used incorrectly, it can
1.18 cvs 4995: pointlessly increase the size of the image constructed by the editor and lead
4996: to excessive memory consumption by the editor.</p>
1.30 cvs 4997:
4998: <p>Like the <tt>PageBreak</tt> and <tt>LineBreak</tt> rules, the
4999: <tt>Gather</tt> rule can only appear in rules of the primary view and applies
5000: to all views defined in the presentation schema.</p>
1.18 cvs 5001: <pre> 'Gather' ':' Boolean .</pre>
5002: </div>
1.1 cvs 5003:
1.18 cvs 5004: <div class="subsection">
1.37 ! cvs 5005: <h3><a name="sectc4224" id="sectc4224">Visibility</a></h3>
1.1 cvs 5006:
1.34 cvs 5007: <p>The visibility property is used to control which elements should or should
1.37 ! cvs 5008: not be displayed, based on context. An element can have different
! 5009: visibilities in different views. If an element's visibility is zero for a
! 5010: view, that element is not displayed in that view and does not occupy any
! 5011: space (its extents are zero).</p>
1.30 cvs 5012:
1.37 ! cvs 5013: <p>Visibility takes non-negative integer values (positive or zero). If values
1.1 cvs 5014: greater than 1 are used, they allow the user to choose a degree of visibility
1.37 ! cvs 5015: and, thus, to see only those boxes whose visibility property exceeds a
! 5016: certain threshold. This gives the user control over the granularity of the
! 5017: displayed pictures.</p>
1.30 cvs 5018:
1.34 cvs 5019: <p>The visibility property can be defined as a constant or by inheritance. If
1.1 cvs 5020: defined by inheritance, it cannot be based on the value of the next or
1.37 ! cvs 5021: previous box. Visibility can only be inherited from above.</p>
1.30 cvs 5022:
5023: <p>If it is a numeric attribute's presentation rule, the visibility can be
1.37 ! cvs 5024: specified by the attribute's name, in which case the value of the attribute
! 5025: is used.</p>
1.18 cvs 5026: <pre> 'Visibility' ':' NumberInherit
1.1 cvs 5027: NumberInherit = Integer / AttrID / Inheritance .
1.18 cvs 5028: Integer = NUMBER .</pre>
1.30 cvs 5029:
1.18 cvs 5030: <blockquote class="example">
1.30 cvs 5031: <p><strong>Example:</strong></p>
5032:
5033: <p>Suppose that only <tt>Formula</tt> elements should be displayed in the
1.37 ! cvs 5034: <tt>MathView</tt> view. Then, the default rules should include:</p>
1.30 cvs 5035: <pre>DEFAULT
1.18 cvs 5036: IN MathView Visibility:0;</pre>
1.30 cvs 5037:
1.31 cvs 5038: <p>which makes all elements invisible in the <tt>MathView</tt> view.
1.30 cvs 5039: However, the <tt>Formula</tt> element also has a <tt>Visibility</tt>
5040: rule:</p>
5041: <pre>Formula :
1.18 cvs 5042: IN MathView Visibility:5;</pre>
1.30 cvs 5043:
5044: <p>which makes formulas, and only formulas, visible.</p>
1.18 cvs 5045: </blockquote>
5046: </div>
1.1 cvs 5047:
1.18 cvs 5048: <div class="subsection">
1.37 ! cvs 5049: <h3><a name="sectc4225" id="sectc4225">Character style properties</a></h3>
1.1 cvs 5050:
1.34 cvs 5051: <p>Four properties are used to determine which characters are used to display
1.37 ! cvs 5052: text. They are size, font, style, and underlining.</p>
1.1 cvs 5053:
1.18 cvs 5054: <div class="subsubsection">
1.37 ! cvs 5055: <h4><a name="sectd42251" id="sectd42251">Character size</a></h4>
1.30 cvs 5056:
1.37 ! cvs 5057: <p>The size property has two effects. First, it is used to specify the actual
1.34 cvs 5058: size and distance units for boxes defined in <a href="#sectc4217">relative
1.37 ! cvs 5059: units</a>. Second, it defines the size of the characters contained in the
1.34 cvs 5060: box.</p>
1.1 cvs 5061:
1.30 cvs 5062: <p>As a distance or length, the size can be expressed in abstract or absolute
1.37 ! cvs 5063: units. It can also be inherited. If it is not inherited, it is expressed
! 5064: simply as an integer followed by the <tt>pt</tt> keyword, which indicates
! 5065: that the size is expressed in typographer's points. The absence of the
! 5066: <tt>pt</tt> keyword indicates that it is in abstract units in which the value
! 5067: 1 represents the smallest size while the value 16 is the largest size. The
! 5068: relationship between these abstract sizes and the real character sizes is
! 5069: controlled by a table which can be modified statically or even dynamically
! 5070: during the execution of the Thot editor.</p>
1.30 cvs 5071:
5072: <p>If the <tt>Size</tt> rule is a numeric attribute's presentation rule, the
1.34 cvs 5073: value of the size property can be specified by the attribute's name, in which
1.30 cvs 5074: case the value of the attribute is used.</p>
5075:
1.37 ! cvs 5076: <p><strong>Note:</strong> the only unit available for defining an absolute
! 5077: size is the typographer's point. Centimeters and inches may not be used.</p>
1.30 cvs 5078:
5079: <p>If the size is inherited, the rule must specify the relative from which to
5080: inherit and any percentage or difference from that relative's value. A
5081: percentage is indicated by a <tt>*</tt> followed by the value of the
5082: percentage and a <tt>%</tt>. A difference can be expressed in either
5083: typographer's points or in abstract units and the maximum or minimum size can
1.37 ! cvs 5084: be specified, but without specifying the unit: it is the same as was
! 5085: specified for the difference.</p>
1.30 cvs 5086:
5087: <p>In a numeric attribute's presentation rule, the difference in size or the
1.22 cvs 5088: percentage can be indicated by the attribute's name instead of the numeric
1.37 ! cvs 5089: value, which means that the attribute's value should be used as the
! 5090: difference or percentage. The attribute can also be used as the minimum or
! 5091: maximum size for a difference.</p>
1.22 cvs 5092: <pre> 'Size' ':' SizeInherit
5093: SizeInherit = SizeAttr [ 'pt' ] /
5094: Kinship InheritedSize .
5095: InheritedSize ='+' SizeAttr [ 'pt' ]
5096: [ 'Max' MaxSizeAttr ] /
5097: '-' SizeAttr [ 'pt' ]
5098: [ 'Min' MinSizeAttr ] /
5099: '*' PercentSizeAttr '%' /
5100: '=' .
5101: SizeAttr = Size / AttrID .
5102: Size = NUMBER .
5103: MaxSizeAttr = MaxSize / AttrID .
5104: MaxSize = NUMBER .
5105: MinSizeAttr = MinSize / AttrID .
5106: MinSize = NUMBER .
5107: PercentSizeAttr = PercentSize / AttrID .
5108: PercentSize = NUMBER .</pre>
1.30 cvs 5109:
1.18 cvs 5110: <blockquote class="example">
1.30 cvs 5111: <p><strong>Example:</strong></p>
5112:
5113: <p>The rule</p>
5114: <pre>Size : Enclosing - 2 pt Min 7;</pre>
5115:
5116: <p>states that the character size is 2 points less than that of the
5117: enclosing box, but that it may not be less than 7 points, whatever the
5118: enclosing box's value.</p>
5119:
5120: <p>The following rules make the text of a report be displayed with
5121: medium-sized characters (for example, size 5), while the title is displayed
5122: with larger characters and the summary is displayed with smaller
5123: characters:</p>
5124: <pre>Report :
1.1 cvs 5125: Size : 5;
5126: Title :
5127: Size : Enclosing + 2;
5128: Summary :
1.18 cvs 5129: Size : Enclosing - 1;</pre>
1.30 cvs 5130:
5131: <p>Thus, the character sizes in the entire document can be changed by
1.34 cvs 5132: changing the size property of the Report element, while preserving the
1.30 cvs 5133: relationships between the sizes of the different elements.</p>
1.18 cvs 5134: </blockquote>
5135: </div>
5136:
5137: <div class="subsubsection">
1.37 ! cvs 5138: <h4><a name="sectd42252" id="sectd42252">Font and character style</a></h4>
1.18 cvs 5139:
1.37 ! cvs 5140: <p>The <tt>Font</tt> rule determines the font family to be used to display
! 5141: the characters contained in the box, while the <tt>Style</tt> rule determines
! 5142: their style and the <tt>Weight</tt> rule determines their weight. Thot
1.23 cvs 5143: recognizes three character fonts (Times, Helvetica, and Courier), three
5144: styles: Roman, Italics, and Oblique, and two weights: Normal and Bold.</p>
1.30 cvs 5145:
5146: <p>The font family, style and weight can be specified by a named constant or
1.37 ! cvs 5147: can be inherited. For the name of the font family only the first character is
1.30 cvs 5148: used.</p>
5149:
5150: <p>Only identical inheritance is allowed: the box takes the same font, style
1.37 ! cvs 5151: or weight as the box from which it inherits. This is indicated by an equals
1.23 cvs 5152: sign after the kinship specification.</p>
5153: <pre> 'Font' ':' NameInherit /
5154: 'Style' ':' StyleInherit /
5155: 'Weight' ':' WeightInherit /
5156:
5157: NameInherit = Kinship '=' / FontName .
5158: FontName = NAME .
5159: StyleInherit = Kinship '=' /
5160: 'Roman' / 'Italics' / 'Oblique' .
5161: WeightInherit = Kinship '=' /
5162: 'Normal' / 'Bold' .</pre>
1.30 cvs 5163:
1.18 cvs 5164: <blockquote class="example">
1.30 cvs 5165: <p><strong>Example:</strong></p>
5166:
5167: <p>To specify that the summary uses the font family of the rest of the
5168: document, but in the italic style, the following rules are used:</p>
5169: <pre>Summary :
1.1 cvs 5170: BEGIN
5171: Font : Enclosing =;
5172: Style : Italics;
1.18 cvs 5173: END;</pre>
5174: </blockquote>
5175: </div>
5176:
5177: <div class="subsubsection">
1.37 ! cvs 5178: <h4><a name="sectd42253" id="sectd42253">Underlining</a></h4>
1.18 cvs 5179:
1.30 cvs 5180: <p>The <tt>Underline</tt> rule is used to specify if the characters contained
1.37 ! cvs 5181: in a box should have lines drawn on or near them. There are four underlining
1.18 cvs 5182: styles: <tt>Underlined</tt>, <tt>Overlined</tt>, <tt>CrossedOut</tt>, and
1.37 ! cvs 5183: <tt>NoUnderline</tt>. The <tt>Thickness</tt> rule specifies the thickness of
1.18 cvs 5184: the line, <tt>Thin</tt> or <tt>Thick</tt>.</p>
1.30 cvs 5185:
5186: <p>As with font family and style, only identical inheritance is allowed: the
1.37 ! cvs 5187: box has the same underlining type as the box from which it inherits the
! 5188: value. This is indicated by an equals sign after the kinship
! 5189: specification.</p>
1.18 cvs 5190: <pre> 'Underline' ':' UnderLineInherit /
1.1 cvs 5191: 'Thickness' ':' ThicknessInherit /
5192:
5193: UnderLineInherit = Kinship '=' / 'NoUnderline' /
5194: 'Underlined' /
5195: 'Overlined' / 'CrossedOut' .
1.18 cvs 5196: ThicknessInherit = Kinship '=' / 'Thick' / 'Thin' .</pre>
5197: </div>
5198: </div>
5199:
5200: <div class="subsection">
1.37 ! cvs 5201: <h3><a name="sectc4226" id="sectc4226">Stacking order</a></h3>
1.18 cvs 5202:
1.30 cvs 5203: <p>The <tt>Depth</tt> rule is used to define the stacking order of terminal
1.37 ! cvs 5204: boxes when multiple boxes at least partially overlap. This rule defines how
! 5205: the depth property, which is zero or a positive integer, is calculated. The
! 5206: depth property has a value for all boxes. For terminal boxes in the structure
1.34 cvs 5207: and for presentation boxes, the depth value is used during display and
5208: printing: the boxes with the lowest value overlap those with higher depths.
1.37 ! cvs 5209: For non-terminal boxes, the depth is not interpreted during display, but it
! 5210: is used to calculate the depth of terminal boxes by inheritance.</p>
1.30 cvs 5211:
5212: <p>Like most other rules, the depth rule is defined in the <a
1.37 ! cvs 5213: href="#sectc427">default rules</a> of each presentation schema. Thus, there
1.18 cvs 5214: is always a depth value, even when it is not necessary because there is no
1.37 ! cvs 5215: overlapping. To avoid useless operations, a zero value can be given to the
1.34 cvs 5216: depth property, which signifies that overlapping is never a problem.</p>
1.30 cvs 5217:
5218: <p>The depth rule has the same form as the <a href="#sectc4224">visibility
1.18 cvs 5219: rule</a>. It can be defined by inheritance or by a constant numeric value.
5220: When the rule is attached to a numeric attribute, it can take the value of
5221: that attribute.</p>
5222: <pre> 'Depth' ':' NumberInherit</pre>
1.30 cvs 5223:
1.18 cvs 5224: <blockquote class="example">
1.30 cvs 5225: <p><strong>Example:</strong></p>
5226:
5227: <p>For a purely textual document, in which overlapping never poses a
5228: problem, a single default <tt>Depth</tt> rule in the presentation schema is
5229: sufficient:</p>
5230: <pre>DEFAULT
1.1 cvs 5231: Depth : 0;
1.18 cvs 5232: ...</pre>
1.30 cvs 5233:
5234: <p>To make the text of examples appear on a light blue background, a
5235: presentation box is defined:</p>
5236: <pre>BOXES
1.1 cvs 5237: BlueBG :
5238: BEGIN
5239: Content : Graphics 'R';
5240: Background : LightBlue3;
5241: FillPattern: backgroundcolor;
5242: Depth : 2;
5243: ...
1.18 cvs 5244: END;</pre>
1.30 cvs 5245:
5246: <p>and is created by the <tt>Example</tt> element, which has the rules:</p>
5247: <pre>RULES
1.1 cvs 5248: Example :
5249: BEGIN
5250: CreateFirst (BlueBG);
5251: Depth : 1;
5252: ...
1.18 cvs 5253: END;</pre>
1.30 cvs 5254:
5255: <p>In this way, the text of an example (if it inherits its depth from its
5256: ancestor) will be superimposed on a light blue background, and not the
5257: reverse).</p>
1.18 cvs 5258: </blockquote>
5259: </div>
5260:
5261: <div class="subsection">
1.37 ! cvs 5262: <h3><a name="sectc4227" id="sectc4227">Line style</a></h3>
1.18 cvs 5263:
1.30 cvs 5264: <p>The <tt>LineStyle</tt> rule determines the style of line which should be
5265: used to draw all the elements contained in the box and the box itself, if it
1.37 ! cvs 5266: has a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. The line style can be
1.18 cvs 5267: indicated by a name (<tt>Solid</tt>, <tt>Dashed</tt>, <tt>Dotted</tt>) or it
1.37 ! cvs 5268: can be inherited. All elements of the graphic base type are affected by this
1.1 cvs 5269: rule, but it can be attached to any box and transmitted by inheritance to the
1.37 ! cvs 5270: graphic elements. The border of elements having a <a
1.18 cvs 5271: href="#sectc4230a"><tt>ShowBox</tt> rule</a> is drawn according to the line
5272: style specified by this rule.</p>
1.30 cvs 5273:
1.37 ! cvs 5274: <p>Only identical inheritance is allowed: the box takes the same line style
! 5275: as the box from which it inherits. This is indicated by an equals sign after
! 5276: the kinship specification.</p>
1.18 cvs 5277: <pre> 'LineStyle' ':' LineStyleInherit
1.1 cvs 5278: LineStyleInherit = Kinship '=' /
1.18 cvs 5279: 'Solid' / 'Dashed' / 'Dotted' .</pre>
1.30 cvs 5280:
1.18 cvs 5281: <blockquote class="example">
1.30 cvs 5282: <p><strong>Example:</strong></p>
5283:
1.37 ! cvs 5284: <p>To specify that, in Figures, the graphical parts should be drawn in
! 5285: solid lines, the Figure element is given a rule using the <tt>Solid</tt>
! 5286: name:</p>
1.30 cvs 5287: <pre>Figure :
1.18 cvs 5288: LineStyle : Solid;</pre>
1.30 cvs 5289:
5290: <p>and the elements composing figures are given an inheritance rule:</p>
5291: <pre> LineStyle : Enclosing =;</pre>
1.18 cvs 5292: </blockquote>
5293: </div>
5294:
5295: <div class="subsection">
1.37 ! cvs 5296: <h3><a name="sectc4228" id="sectc4228">Line thickness</a></h3>
1.18 cvs 5297:
1.37 ! cvs 5298: <p>The <tt>LineWeight</tt> rule determines the thickness of the lines of all
1.1 cvs 5299: graphical elements which appear in the box, no matter what their line style.
1.37 ! cvs 5300: Line thickness can be specified by a constant value or by inheritance. A
! 5301: constant value is a positive number followed by an optional unit
! 5302: specification (which is absent when using relative units). All available <a
! 5303: href="#sectc4217">distance units</a> can be used. Line thickness is expressed
1.18 cvs 5304: in the same way as <a href="#sectd42221">line spacing</a>.</p>
5305: <pre> 'LineWeight' ':' DistOrInherit</pre>
1.30 cvs 5306:
1.37 ! cvs 5307: <p>All elements of the graphic base type are affected by this rule, but it
! 5308: can be attached to any box and transmitted by inheritance to the graphic
! 5309: elements. The border of element having a <a
! 5310: href="#sectc4230a"><tt>ShowBox</tt> rule</a> is also drawn according to the
! 5311: thickness specified by this rule.</p>
1.30 cvs 5312:
1.18 cvs 5313: <blockquote class="example">
1.30 cvs 5314: <p><strong>Example:</strong></p>
5315:
5316: <p>To specify that, in Figures, the graphical parts should be drawn with
5317: lines 0.3 pt thick, the Figure element is given this rule:</p>
5318: <pre>Figure :
1.18 cvs 5319: LineWeight : 0.3 pt;</pre>
1.30 cvs 5320:
5321: <p>and the elements composing figures are given an inheritance rule:</p>
5322: <pre> LineWeight : Enclosing =;</pre>
1.18 cvs 5323: </blockquote>
5324: </div>
5325:
5326: <div class="subsection">
1.37 ! cvs 5327: <h3><a name="sectc4229" id="sectc4229">Fill pattern</a></h3>
1.18 cvs 5328:
1.30 cvs 5329: <p>The <tt>FillPattern</tt> rule determines the pattern used to fill closed
1.37 ! cvs 5330: graphical elements (circles, rectangles, etc.) which appear in the box. This
1.18 cvs 5331: rule also specifies the pattern used to fill the box associated with elements
1.37 ! cvs 5332: having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a><a>. This pattern can
! 5333: be indicated by a named constant or by inheritance. The named constant
! 5334: identifies one of the patterns available in Thot. The names of the available
1.18 cvs 5335: patterns are: nopattern, foregroundcolor, backgroundcolor, gray1, gray2,
5336: gray3, gray4, gray5, gray6, gray7, horiz1, horiz2, horiz3, vert1, vert2,
1.37 ! cvs 5337: vert3, left1, left2, left3, right1, right2, right3, square1, square2,
! 5338: square3, lozenge, brick, tile, sea, basket.</a></p>
1.30 cvs 5339:
5340: <p>Like the other rules peculiar to graphics, <tt>LineStyle</tt> and
1.18 cvs 5341: <tt>LineWeight</tt>, only elements of the graphic base type are affected by
5342: the <tt>FillPattern</tt> rule, but the rule can be attached to any box and
1.37 ! cvs 5343: transmitted by inheritance to the graphic elements. As with the other rules
1.18 cvs 5344: specific to graphics, only identical inheritance is allowed.</p>
1.30 cvs 5345:
5346: <p>The <tt>FillPattern</tt> rule can also be used to determine whether or not
1.37 ! cvs 5347: text characters, symbols and pictures should be colored. For these element
1.12 cvs 5348: types (text, symbols, and pictures), the only valid values are
1.18 cvs 5349: <tt>nopattern</tt>, <tt>foregroundcolor</tt>, and <tt>backgroundcolor</tt>.
5350: When <tt>FillPattern</tt> has the value <tt>backgroundcolor</tt>, text
5351: characters, symbols, and bitmaps are given the color specified by the <a
5352: href="#sectc4230"><tt>Background</tt> rule</a> which applies to these
1.37 ! cvs 5353: elements. When <tt>FillPattern</tt> has the value <tt>foregroundcolor</tt>,
1.18 cvs 5354: these same elements are given the color specified by the <a
5355: href="#sectc4230"><tt>Foreground</tt> rule</a> which applies to these
1.37 ! cvs 5356: elements. In all other case, text characters are not colored.</p>
1.18 cvs 5357: <pre> 'FillPattern' ':' NameInherit</pre>
1.30 cvs 5358:
1.18 cvs 5359: <blockquote class="example">
1.30 cvs 5360: <p><strong>Example:</strong></p>
5361:
5362: <p>To specify that, in Figures, the closed graphical elements should be
5363: filled with a pattern resembling a brick wall, the Figure element is given
5364: this rule:</p>
5365: <pre>Figure :
1.18 cvs 5366: FillPattern : brick;</pre>
1.30 cvs 5367:
5368: <p>and the elements composing figures are given an inheritance rule:</p>
5369: <pre> FillPattern : Enclosing =;</pre>
1.18 cvs 5370: </blockquote>
5371: </div>
5372:
5373: <div class="subsection">
1.37 ! cvs 5374: <h3><a name="sectc4230" id="sectc4230">Colors</a></h3>
1.18 cvs 5375:
1.30 cvs 5376: <p>The <tt>Foreground</tt> and <tt>Background</tt> rules determine the
1.37 ! cvs 5377: foreground and background colors of the base elements which appear in the
! 5378: box. They also control the color of boxes associated with elements having a
! 5379: <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. These colors can be
! 5380: specified with a named constant or by inheritance. The named constants
! 5381: specify one of the available colors in Thot. The available color names can be
! 5382: found in the file <tt>thot.color</tt>. In addition to those names, you can
! 5383: use the keyword <code>Transparent</code>, to not draw anything.</p>
! 5384:
! 5385: <p>The color rules affect the same way all base elements and elements having
! 5386: a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>, no matter what their type
! 5387: (text, graphics, pictures, symbols). The color rules can be associated with
1.30 cvs 5388: any box and can be transmitted by inheritance to the base elements or the
1.37 ! cvs 5389: elements having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. Like the
1.30 cvs 5390: preceding rules, only inheritance of the same value is allowed.</p>
5391: <pre> 'Foreground' ':' Color
5392: 'Background' ':' Color
5393: Color = 'Transparent' / Link '=' / FontColorName .</pre>
5394:
5395: <p><strong>Note:</strong> text colors only appear for text elements whose <a
1.18 cvs 5396: href="#sectc4229">fill pattern</a> does not prevent the use of color.</p>
1.30 cvs 5397:
1.18 cvs 5398: <blockquote class="example">
1.30 cvs 5399: <p><strong>Example:</strong></p>
5400:
5401: <p>To specify that, in Figures, everything must be drawn in blue on a
5402: background of yellow, the Figure element is given these rules:</p>
5403: <pre>Figure :
1.1 cvs 5404: BEGIN
5405: Foreground : Blue;
5406: Background : Yellow;
5407: Fillpattern : backgroundcolor;
1.18 cvs 5408: END;</pre>
1.30 cvs 5409:
5410: <p>and the elements composing figures are given inheritance rules:</p>
5411: <pre> Foreground : Enclosing =;
1.1 cvs 5412: Background : Enclosing =;
1.18 cvs 5413: FillPattern : Enclosing =;</pre>
5414: </blockquote>
5415: </div>
5416:
5417: <div class="subsection">
1.37 ! cvs 5418: <h3><a name="sectc4230a" id="sectc4230a">Background color and border</a></h3>
1.18 cvs 5419:
1.30 cvs 5420: <p>Boxes associated with structural elements are normally not visible, but it
1.37 ! cvs 5421: is possible to draw their border and/or to paint their area when it is
! 5422: needed. This is achieved by associating the <tt>ShowBox</tt> rule with the
! 5423: concerned element. This rule has no parameter and no value. It is simply
! 5424: written <tt>Showbox;</tt>. It is not inherited nor transmitted to any other
! 5425: element. It applies only to the element with which it is associated.</p>
1.18 cvs 5426: <pre> 'ShowBox'</pre>
1.30 cvs 5427:
5428: <p>When an element has a <tt>ShowBox</tt> rule, the border is drawn only if
1.37 ! cvs 5429: the <tt>LineWeight</tt> rule that applies to that element has a non-zero
! 5430: value (this value can be inherited). The color, style and thickness of the
! 5431: border are defined by the <tt>Foreground</tt>, <tt>LineStyle</tt>, and
1.18 cvs 5432: <tt>LineWeight</tt> rules that apply to the element.</p>
1.30 cvs 5433:
1.37 ! cvs 5434: <p>When an element has a <tt>ShowBox</tt> rule, the background of this
! 5435: element is paint only if the value of the <tt>FillPattern</tt> rule that
! 5436: applies to that element is not <tt>nopattern</tt>. The pattern and color(s)
! 5437: of the background are defined by the <tt>FillPattern</tt>,
! 5438: <tt>Background</tt>, and <tt>Foreground</tt> rules that apply to the
! 5439: element.</p>
1.18 cvs 5440: </div>
5441:
5442: <div class="subsection">
1.37 ! cvs 5443: <h3><a name="sectc4230b" id="sectc4230b">Background pictures</a></h3>
1.18 cvs 5444:
1.30 cvs 5445: <p>The <tt>BackgroundPicture</tt> rule allows to display a picture as the
1.37 ! cvs 5446: background of an element. It has a single parameter, the file name of the
! 5447: picture. This is a string delimited by single quotes. If the first character
1.18 cvs 5448: in this string is '/', it is considered as an absolute path, otherwise the
1.37 ! cvs 5449: file is searched for along the schema directory path. This file may contain a
1.18 cvs 5450: picture in any format accepted by Thot (xbm, xpm, gif, jpeg, png, etc.)</p>
1.30 cvs 5451:
1.37 ! cvs 5452: <p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only
! 5453: to the element with which they are associated. They are not inherited nor
1.18 cvs 5454: transmitted to children elements.</p>
1.30 cvs 5455:
5456: <p>The background picture has not always the same size as the element's box.
1.37 ! cvs 5457: There are diffrent ways to fill the element box with the picture. This is
1.18 cvs 5458: specified by the <tt>PictureMode</tt> rule, which should be associated to the
1.37 ! cvs 5459: same element. This rule may take one of the following values:</p>
1.18 cvs 5460: <dl>
1.30 cvs 5461: <dt><tt>NormalSize</tt></dt>
5462: <dd>The picture is centered in the box, and clipped if it is too
5463: large.</dd>
5464: <dt><tt>Scale</tt></dt>
5465: <dd>The picture is zoomed to fit the box size.</dd>
5466: <dt><tt>RepeatX</tt></dt>
5467: <dd>The picture is repeated horizontally to fit the box width.</dd>
5468: <dt><tt>RepeatY</tt></dt>
5469: <dd>The picture is repeated vertically to fit the box height.</dd>
5470: <dt><tt>RepeatXY</tt></dt>
5471: <dd>The picture is repeated both horizontally and vertically to fill the
5472: box.</dd>
1.18 cvs 5473: </dl>
1.30 cvs 5474:
5475: <p>If an element has a <tt>BackgroundPicture</tt> rule and no
1.18 cvs 5476: <tt>PictureMode</tt> rule, the <tt>NormalSize</tt> value is assumed.</p>
5477: <pre> 'BackgroundPicture' ':' FileName /
1.13 cvs 5478: 'PictureMode' ':' PictMode .
5479:
5480: FileName = STRING .
1.18 cvs 5481: PictMode = 'NormalSize' / 'Scale' / 'RepeatXY' / 'RepeatX' / 'RepeatY' .</pre>
1.30 cvs 5482:
1.37 ! cvs 5483: <p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only
! 5484: to the element with which they are associated. They are not inherited nor
1.18 cvs 5485: transmitted to children elements.</p>
5486: </div>
1.13 cvs 5487:
1.18 cvs 5488: <div class="subsection">
1.37 ! cvs 5489: <h3><a name="sectc4231" id="sectc4231">Presentation box content</a></h3>
1.1 cvs 5490:
1.37 ! cvs 5491: <p>The <tt>Content</tt> rule applies to presentation boxes. It indicates the
! 5492: content given to a box. This content is either a variable's value or a
! 5493: constant value.</p>
1.30 cvs 5494:
5495: <p>If the content is a constant, it can be specified, as in a variable
1.18 cvs 5496: declaration, either by the name of a constant declared in the <tt>CONST</tt>
1.1 cvs 5497: section or by direct specification of the type and value of the box's
1.18 cvs 5498: content.</p>
1.30 cvs 5499:
5500: <p>Similarly, if it is a variable, the name of a variable declared in
1.18 cvs 5501: <tt>VAR</tt> section can be given or the variable may be defined within
1.37 ! cvs 5502: parentheses. The content inside the parentheses has the same syntax as a <a
1.18 cvs 5503: href="#sectc426">variable declaration</a>.</p>
5504: <pre> 'Content' ':' VarConst
1.1 cvs 5505: VarConst = ConstID / ConstType ConstValue /
1.37 ! cvs 5506: VarID / '(' FunctionSeq ')' .
! 5507: </pre>
1.30 cvs 5508:
5509: <p>A presentation box can have only one <tt>Content</tt> rule, which means
1.37 ! cvs 5510: that the content of a presentation box cannot vary from view to view.
! 5511: However, such an effect can be achieved by creating several presentation
! 5512: boxes, each with different content and visible in different views.</p>
! 5513:
! 5514: <p>The <tt>Content</tt> rule also applies to elements defined as references
! 5515: in the structure schema. In this case, the content defined by the rule must
! 5516: be a constant. It is this content which appears on the screen or paper to
! 5517: represent references of the type to which the rule applies. A reference can
1.18 cvs 5518: have a <tt>Content</tt> rule or a <a href="#sectc4234"><tt>Copy</tt> rule</a>
1.37 ! cvs 5519: for each view. If neither of these rules appears, the reference is displayed
1.18 cvs 5520: as <tt>[*]</tt>, which is equivalent to the rule:</p>
5521: <pre> Content: Text '[*]';</pre>
1.30 cvs 5522:
1.18 cvs 5523: <blockquote class="example">
1.30 cvs 5524: <p><strong>Example:</strong></p>
5525:
5526: <p>The content of the presentation box created to make the chapter number
5527: and section number appear before each section title can be defined by:</p>
5528: <pre>BOXES
1.1 cvs 5529: SectionNumBox :
5530: BEGIN
5531: Content : NumSection;
5532: ...
1.18 cvs 5533: END;</pre>
1.30 cvs 5534:
5535: <p>if the <tt>NumSection</tt> variable has been defined in the variable
1.37 ! cvs 5536: definition section of the presentation schema. Otherwise the
1.30 cvs 5537: <tt>Content</tt> would be written:</p>
5538: <pre>BOXES
1.1 cvs 5539: SectionNumBox :
5540: BEGIN
5541: Content : (VALUE (ChapterCtr, Roman) TEXT '.'
5542: VALUE (SectionCtr, Arabic));
5543: ...
1.18 cvs 5544: END;</pre>
5545: </blockquote>
5546: </div>
1.1 cvs 5547:
1.18 cvs 5548: <div class="subsection">
1.37 ! cvs 5549: <h3><a name="sectc4232" id="sectc4232">Presentation box creation</a></h3>
1.1 cvs 5550:
1.37 ! cvs 5551: <p>A creation rule specifies that a presentation box should be created when
! 5552: an element of the type to which the rule is attached appears in the
! 5553: document.</p>
1.30 cvs 5554:
5555: <p>A keyword specifies the position, relative to the creating box, at which
5556: the created box will be placed in the structure:</p>
1.18 cvs 5557: <dl>
1.30 cvs 5558: <dt><tt>CreateFirst</tt></dt>
5559: <dd>specifies that the box should be created as the first box of the next
5560: lower level, before any already existing boxes, and only if the
5561: beginning of the creating element is visible;</dd>
5562: <dt><tt>CreateLast</tt></dt>
5563: <dd>specifies that the box should be created as the last box of the next
5564: lower level, after any existing boxes, and only if the end of the
5565: creating element is visible;</dd>
5566: <dt><tt>CreateBefore</tt></dt>
5567: <dd>specifies that the box should be created before the creating box, on
5568: the same level as the creating box, and only if the beginning of the
5569: creating element is visible;</dd>
5570: <dt><tt>CreateAfter</tt></dt>
5571: <dd>specifies that the box should be created after the creating box, on
5572: the same level as the creating box, and only if the beginning of the
5573: creating element is visible;</dd>
5574: <dt><tt>CreateEnclosing</tt></dt>
1.37 ! cvs 5575: <dd>specifies that the box should be created at the upper level
! 5576: relatively to the creating box, and that it must contain that creating
! 5577: box and all presentation boxes created by the same creating box.</dd>
1.18 cvs 5578: </dl>
1.30 cvs 5579:
5580: <p>This keyword can be followed by the <tt>Repeated</tt> keyword to indicate
5581: that the box must be created for each part of the creating element. These
5582: parts result from the division of the element by page breaks or column
1.37 ! cvs 5583: changes. If the <tt>Repeated</tt> keyword is missing, the box is only created
1.30 cvs 5584: for the first part of the creating element (<tt>CreateFirst</tt> and
1.18 cvs 5585: <tt>CreateBefore</tt> rules) or for the last part (<tt>CreateLast</tt> and
5586: <tt>CreateAfter</tt> rules).</p>
1.30 cvs 5587:
5588: <p>The type of presentation to be created is specified at the end of the rule
1.18 cvs 5589: between parentheses.</p>
1.30 cvs 5590:
5591: <p>Creation rules cannot appear in the <a href="#sectc427">default
1.37 ! cvs 5592: presentation rules</a>. The boxes being created should have a
1.30 cvs 5593: <tt>Content</tt> rule which indicates their <a
5594: href="#sectc4231">content</a>.</p>
5595:
5596: <p>Creation rules can only appear in the block of rules for the primary view;
1.1 cvs 5597: creation is provoked by a document element for all views. However, for each
1.37 ! cvs 5598: view, the presentation box is only created if the creating element is itself
! 5599: a box in the view. Moreover, the visibility property of the presentation box
! 5600: can be adjusted to control the creation of the box on a view-by-view
! 5601: basis.</p>
1.18 cvs 5602: <pre> Creation '(' BoxID ')'
1.1 cvs 5603: Creation = Create [ 'Repeated' ] .
5604: Create ='CreateFirst' / 'CreateLast' /
5605: 'CreateBefore' / 'CreateAfter' /
1.18 cvs 5606: 'CreateEnclosing' .</pre>
1.30 cvs 5607:
1.18 cvs 5608: <blockquote class="example">
1.30 cvs 5609: <p><strong>Example:</strong></p>
5610:
5611: <p>Let us define an object type, called Table, which is composed of a
5612: sequence of columns, all having the same fixed width, where the columns are
1.37 ! cvs 5613: separated by vertical lines. There is a line to the left of the first
! 5614: column and one to the right of the last. Each column has a variable number
1.31 cvs 5615: of cells, placed one on top of the other and separated by horizontal lines.
5616: There are no horizontal lines above the first cell or below the last cell.
1.37 ! cvs 5617: The text contained in each cell is broken into lines and these lines are
1.30 cvs 5618: centered horizontally in the cell. The logical structure of this object is
5619: defined by:</p>
5620: <pre>Table = LIST OF (Column);
1.18 cvs 5621: Column = LIST OF (Cell = Text);</pre>
5622:
1.30 cvs 5623: <div class="figure">
1.37 ! cvs 5624: <hr />
1.30 cvs 5625: <pre>| | | |
1.1 cvs 5626: | xx xxxx xxxx |x xxxx xxx xxxxx| x xxx x xxx |
5627: | xxx xxx xxxx x | x xx x xxx | xxxxx xxxx xx |
5628: | xxxxx xxxx |----------------| xxx xxxxx x |
5629: | xxxxx xxx xxxx | xxxx xx xx xxx | xx xx |
5630: | xxx xxxx x xxx | xxxx x xxx x |---------------|
5631: |----------------| xxx xxxx xxxxx | xxxxx xxxxx |
5632: | xxx xxx xxxxxx |----------------| xxx xxxx xxxx |
5633: | xxxx xxxx xx | xxxx xx x xx | xxx xx x xx |
5634: |----------------| xxx xxxxx xxxx | xxxx xxxx xxx |
5635: | xxxxx xxx xxxx | xxxx xx x xx | xxxxx xxx |
1.18 cvs 5636: |xxxx xx x xxxxxx| xxxx xx xxxxxx | xxxxx xxxxx |</pre>
1.19 cvs 5637:
1.37 ! cvs 5638: <p align="center"><em><a name="table" id="table">The design of a
! 5639: table</a></em></p>
! 5640: <hr />
1.30 cvs 5641: </div>
5642:
5643: <p>The presentation of the table should resemble the design of the above <a
1.37 ! cvs 5644: href="#table">figure</a>. It is defined by the following presentation
1.30 cvs 5645: schema fragment:</p>
5646: <pre>BOXES
1.1 cvs 5647: VertLine : BEGIN
5648: Width : 0.3 cm;
5649: Height : Enclosing . Height;
5650: VertPos : Top = Enclosing . Top;
5651: HorizPos : Left = Previous . Right;
5652: Content : Graphics 'v';
5653: END;
5654:
5655: HorizLine: BEGIN
5656: Width : Enclosing . Width;
5657: Height : 0.3 cm;
5658: VertPos : Top = Previous . Bottom;
5659: HorizPos : Left = Enclosing . Left;
5660: Content : Graphics 'h';
5661: END;
5662:
5663: RULES
1.6 cvs 5664: Column : BEGIN
5665: CreateBefore (VertLine);
5666: IF LAST CreateAfter (VertLine);
5667: Width : 2.8 cm;
5668: Height : Enclosed . Height;
5669: VertPos : Top = Enclosing . Top;
5670: HorizPos : Left = Previous . Right;
5671: END;
5672:
5673: Cell : BEGIN
5674: IF NOT FIRST CreateBefore (HorizLine);
5675: Width : Enclosing . Width;
5676: Height : Enclosed . Height;
5677: VertPos : Top = Previous . Bottom;
5678: HorizPos : Left = Enclosing . Left;
5679: Line;
5680: Adjust : VMiddle;
1.18 cvs 5681: END;</pre>
1.30 cvs 5682:
5683: <p>It is useful to note that the horizontal position rule of the first
5684: vertical line will not be applied, since there is no preceding box. In this
5685: case, the box is simply placed on the left side of the enclosing box.</p>
1.18 cvs 5686: </blockquote>
5687: </div>
5688:
5689: <div class="subsection">
1.37 ! cvs 5690: <h3><a name="sectc4233" id="sectc4233">Page layout</a></h3>
1.18 cvs 5691:
1.30 cvs 5692: <p>The page models specified in the <tt>Page</tt> rule are defined by boxes
1.37 ! cvs 5693: declared in the <tt>BOXES</tt> section of the presentation schema. Pages are
1.1 cvs 5694: not described as frames which will be filled by the document's text, but as
5695: element are inserted in the flow of the document and which mark the page
1.37 ! cvs 5696: breaks. Each of these page break elements contains presentation boxes which
1.1 cvs 5697: represent the footer boxes of a page followed by header boxes of the next
1.37 ! cvs 5698: page. The page box itself is the simple line which separates two pages on the
! 5699: screen. Both the footer and header boxes placed themselves with respect to
1.1 cvs 5700: this page box, with the footer being placed above it and the header boxes
1.18 cvs 5701: being placed above it.</p>
1.30 cvs 5702:
5703: <p>The boxes created by a page box are headers and footers and can only place
1.1 cvs 5704: themselves vertically with respect to the page box itself (which is in fact
1.37 ! cvs 5705: the separation between two pages). Besides, it is their vertical position
! 5706: rule which determines whether they are header or footer boxes. Header and
1.1 cvs 5707: footer boxes must have an explicit vertical position rule (they must not use
1.18 cvs 5708: the default rule).</p>
1.30 cvs 5709:
5710: <p>Footer boxes must have an absolute height or inherit the height of their
1.18 cvs 5711: contents:</p>
5712: <pre>Height : Enclosed . Height;</pre>
1.30 cvs 5713:
5714: <p>A page box must have height and width rules and these two rules must be
1.1 cvs 5715: specified with constant values, expressed in centimeters, inches, or
1.37 ! cvs 5716: typographer's points. These two rules are interpreted in a special way for
! 5717: page boxes: they determine the width of the page and the vertical distance
1.1 cvs 5718: between two page separators, which is the height of the page and its header
1.18 cvs 5719: and footer together.</p>
1.30 cvs 5720:
5721: <p>A page box should also have vertical and horizontal position rules and
5722: these two rules should specify the position on the sheet of paper of the
1.37 ! cvs 5723: rectangle enclosing the page's contents. These two rules must position the
1.30 cvs 5724: upper left corner of the enclosing rectangle in relation to the upper left
1.37 ! cvs 5725: corner of the sheet of paper, considered to be the enclosing element. In both
1.30 cvs 5726: rules, distances must be expressed in fixed units: centimeters (<tt>cm</tt>),
1.37 ! cvs 5727: inches (<tt>in</tt>), or typographer's points (<tt>pt</tt>). Thus, rules
1.30 cvs 5728: similar to the following should be found in the rules for a page box:</p>
1.18 cvs 5729: <pre>BOXES
1.1 cvs 5730: ThePage :
5731: BEGIN
5732: VertPos : Top = Enclosing . Top + 3 cm;
5733: HorizPos : Left = Enclosing . Left + 2.5 cm;
5734: Width : 16 cm;
5735: Height : 22.5 cm;
1.18 cvs 5736: END;</pre>
1.30 cvs 5737:
5738: <p>When a document must be page broken, the page models to be constructed are
1.18 cvs 5739: defined in the <tt>BOXES</tt> section of the presentation schema by declaring
1.37 ! cvs 5740: page boxes and header and footer boxes. Also, the <tt>Page</tt> rule is used
! 5741: to specify to which parts of the document and to which views each model
! 5742: should be applied.</p>
1.30 cvs 5743:
5744: <p>The <tt>Page</tt> rule has only one parameter, given between parentheses
1.37 ! cvs 5745: after the <tt>Page</tt> keyword. This parameter is the name of the box which
! 5746: must serve as the model for page construction. When a <tt>Page</tt> rule is
1.1 cvs 5747: attached to an element type, each time such an element appears in a document,
5748: a page break takes place and the page model indicated in the rule is applied
5749: to all following pages, until reaching the next element which has a
1.18 cvs 5750: <tt>Page</tt> rule.</p>
1.30 cvs 5751:
5752: <p>The <tt>Page</tt> rule applies to only one view; if it appears in the
1.37 ! cvs 5753: primary view's block of rules, a <tt>Page</tt> rule applies only to that
! 5754: view. Thus, different page models can be defined for the full document and
! 5755: for its table of contents, which is another view of the same document. Some
! 5756: views can be specified with pages, and other views of the same document can
! 5757: be specified without pages.</p>
1.18 cvs 5758: <pre> 'Page' '(' BoxID ')'</pre>
5759: </div>
5760:
5761: <div class="subsection">
1.37 ! cvs 5762: <h3><a name="sectc4234" id="sectc4234">Box copies</a></h3>
1.18 cvs 5763:
1.30 cvs 5764: <p>The <tt>Copy</tt> rule can be used for an element which is defined as a
1.37 ! cvs 5765: reference in the structure schema. In this case, the rule specifies, between
1.18 cvs 5766: parenthesis, the name of the box (declared in the <tt>BOXES</tt> section)
1.1 cvs 5767: which must be produced when this reference appears in the structure of a
1.37 ! cvs 5768: document. The box produced is a copy (same contents, but possible different
1.1 cvs 5769: presentation) of the box type indicated by the parameter between parentheses,
1.37 ! cvs 5770: and which is in the element designated by the reference. The name of a box
1.1 cvs 5771: can be replaced by type name. Then what is copied is the contents of the
1.18 cvs 5772: element of this type which is inside the referenced element.</p>
1.30 cvs 5773:
1.37 ! cvs 5774: <p>Whether a box name or type name is given, it may be followed by the name
! 5775: of a structure schema between parentheses. This signifies that the box or
! 5776: type is defined in the indicated structure schema and not in the structure
! 5777: schema with which the rule's presentation schema is associated.</p>
1.30 cvs 5778:
1.37 ! cvs 5779: <p>The <tt>Copy</tt> rule can also be applied to a presentation box. If the
1.1 cvs 5780: presentation box was created by a reference attribute, the rule is applied as
5781: in the case of a reference element: the contents of the box having the
1.18 cvs 5782: <tt>Copy</tt> rule are based on the element designated by the reference
1.37 ! cvs 5783: attribute. For other presentation boxes, the <tt>Copy</tt> rule takes a type
1.1 cvs 5784: name parameter which can be followed, between parentheses, by the name of the
5785: structure schema in which the type is defined, if it is not defined in the
1.37 ! cvs 5786: same schema. The contents of the box which has this rule are a copy of the
! 5787: element of this type which is in the element creating the presentation box,
! 5788: or by default, the box of this type which precedes the presentation box. This
! 5789: last facility is used, for example, to define the running titles in headers
! 5790: or footers.</p>
1.18 cvs 5791: <pre> 'Copy' '(' BoxTypeToCopy ')' .
1.1 cvs 5792: BoxTypeToCopy = BoxID [ ExtStruct ] /
1.6 cvs 5793: ElemID [ ExtStruct ] .
1.18 cvs 5794: ExtStruct = '(' ElemID ')' .</pre>
1.30 cvs 5795:
5796: <p>Like the creation rules, the <tt>Copy</tt> rule cannot appear in the <a
1.37 ! cvs 5797: href="#sectc427">default presentation rules</a>. Moreover, this rule can only
1.18 cvs 5798: appear in the primary view's block of rules; the copy rule is applied to all
5799: views.</p>
1.30 cvs 5800:
1.18 cvs 5801: <blockquote class="example">
1.30 cvs 5802: <p><strong>Example:</strong></p>
5803:
5804: <p>If the following definitions are in the structure schema:</p>
5805: <pre>Body = LIST OF (Chapter =
1.1 cvs 5806: BEGIN
5807: ChapterTitle = Text;
5808: ChapterBody = SectionSeq;
5809: END);
1.18 cvs 5810: RefChapter = REFERENCE (Chapter);</pre>
1.30 cvs 5811:
5812: <p>then the following presentation rules (among many other rules in the
5813: presentation schema) can be specified:</p>
5814: <pre>COUNTERS
1.1 cvs 5815: ChapterCtr : RANK OF Chapter;
5816: BOXES
5817: ChapterNumber :
5818: BEGIN
5819: Content : (VALUE (ChapterCtr, URoman));
5820: ...
5821: END;
5822: RULES
5823: Chapter :
5824: BEGIN
5825: CreateFirst (ChapterNumber);
5826: ...
5827: END;
5828: RefChapter :
5829: BEGIN
5830: Copy (ChapterNumber);
5831: ...
1.18 cvs 5832: END;</pre>
1.30 cvs 5833:
5834: <p>which makes the number of the chapter designated by the reference appear
5835: in uppercase roman numerals, in place of the reference to a chapter itself.
5836: Alternatively, the chapter title can be made to appear in place of the
5837: reference by writing this <tt>Copy</tt>rule:</p>
5838: <pre> Copy (ChapterTitle);</pre>
5839:
5840: <p>To define a header box, named <tt>RunningTitle</tt>, which contains the
5841: title of the current chapter, the box's contents are defined in this
5842: way:</p>
5843: <pre>BOXES
1.1 cvs 5844: RunningTitle :
1.18 cvs 5845: Copy (ChapterTitle);</pre>
5846: </blockquote>
5847: </div>
5848: </div>
1.37 ! cvs 5849: <hr />
1.18 cvs 5850: </div>
1.1 cvs 5851:
1.18 cvs 5852: <div class="chapter">
1.37 ! cvs 5853: <h1><a name="sect5" id="sect5">The T language</a></h1>
1.1 cvs 5854:
1.18 cvs 5855: <div class="section">
1.37 ! cvs 5856: <h2><a name="sectb51" id="sectb51">Document translation</a></h2>
1.1 cvs 5857:
1.30 cvs 5858: <p>Because of its document model, Thot can produce documents in a high-level
1.37 ! cvs 5859: abstract form. This form, called the <em>canonical form</em> is specific to
1.1 cvs 5860: Thot; it is well suited to the editor's manipulations, but it does not
1.37 ! cvs 5861: necessarily suit other operations which might be applied to documents.
! 5862: Because of this, the Thot editor offers the choice of saving documents in its
! 5863: own form (the canonical form) or a format defined by the user. In the latter
! 5864: case, the Thot document is transformed by the translation program. This
! 5865: facility can also be used to export documents from Thot to systems using
! 5866: other formalisms.</p>
1.1 cvs 5867:
1.18 cvs 5868: <div class="subsection">
1.37 ! cvs 5869: <h3><a name="sectc511" id="sectc511">Translation principles</a></h3>
1.1 cvs 5870:
1.30 cvs 5871: <p>Document translation allows the export of documents to other systems which
1.37 ! cvs 5872: do not accept Thot's canonical form. Translation can be used to export
1.30 cvs 5873: document to source-based formatters like T<sub><big>E</big></sub>X,
1.37 ! cvs 5874: L<sup>A</sup>T<sub><big>E</big></sub>X, and <tt>troff</tt>. It can also be
! 5875: used to translate documents into interchange formats like SGML or HTML. To
1.1 cvs 5876: allow the widest range of possible exports, Thot does not limit the choice of
5877: translations, but rather allows the user to define the formalisms into which
1.18 cvs 5878: documents can be translated.</p>
1.30 cvs 5879:
5880: <p>For each document or object class, a set of translation rules can be
5881: defined, specifying how the canonical form should be transformed into a given
1.37 ! cvs 5882: formalism. These translation rules are grouped into <em>translation
1.18 cvs 5883: schemas</em>, each schema containing the rules necessary to translate a
1.1 cvs 5884: generic logical structure (document or object structure) into a particular
1.37 ! cvs 5885: formalism. The same generic logical structure can have several different
1.1 cvs 5886: translation schemas, each defining translation rules for a different
1.18 cvs 5887: formalism.</p>
1.30 cvs 5888:
1.37 ! cvs 5889: <p>Like presentation schemas, translation schemas are generic. Thus, they
1.30 cvs 5890: apply to an entire object or document class and permit translation of all
5891: documents or objects of that class.</p>
1.18 cvs 5892: </div>
1.1 cvs 5893:
1.18 cvs 5894: <div class="subsection">
1.37 ! cvs 5895: <h3><a name="sectc512" id="sectc512">Translation procedure</a></h3>
1.1 cvs 5896:
1.30 cvs 5897: <p>The translator works on the specific logical structure of the document
1.37 ! cvs 5898: being translated. It traverses the primary tree of this logical structure in
1.1 cvs 5899: pre-order and, at each node encountered, it applies the corresponding
5900: translation rules defined in the translation schema. Translation can be
1.18 cvs 5901: associated:</p>
5902: <ul>
1.30 cvs 5903: <li>with element types defined in the structure schema,</li>
5904: <li>with global or local attributes defined in the structure schema,</li>
5905: <li>with specific presentation rules,</li>
1.37 ! cvs 5906: <li>with the content of the leaves of the structure (characters, symbols
1.30 cvs 5907: and graphical elements)</li>
1.18 cvs 5908: </ul>
1.30 cvs 5909:
5910: <p>Thus, for each node, the translator applies all rules associated with the
1.1 cvs 5911: element type, all rules associated with each attribute (local or global)
5912: carried by the element, and if the element is a leaf of the tree, it also
1.10 cvs 5913: applies translation rules for characters, symbols, or graphical elements,
1.18 cvs 5914: depending on the type of the leaf.</p>
1.30 cvs 5915:
5916: <p>Rules associated with the content of leaves are different from all other
1.1 cvs 5917: rules: they specify only how to translate character strings, symbols, and
1.37 ! cvs 5918: graphical elements. All other rules, whether associated with element types,
1.1 cvs 5919: with specific presentation rules or with attributes, are treated similarly.
1.18 cvs 5920: These rules primarily allow:</p>
5921: <ul>
1.30 cvs 5922: <li>generation of a text constant or variable before or after the contents
5923: of an element,</li>
5924: <li>modification of the order in which elements appear after
5925: translation,</li>
5926: <li>removal of an element in the translated document,</li>
5927: <li>and writing messages on the user's terminal during translation.</li>
1.18 cvs 5928: </ul>
5929: </div>
5930: </div>
1.1 cvs 5931:
1.18 cvs 5932: <div class="section">
1.37 ! cvs 5933: <h2><a name="sectb52" id="sectb52">Translation definition language</a></h2>
1.1 cvs 5934:
1.30 cvs 5935: <p>Translation schemas are written in a custom language, called T, which is
1.37 ! cvs 5936: described in the rest of this chapter. The grammar of T is specified using
1.18 cvs 5937: the same <a href="#sectc321">meta-language</a> as was used for the S and P
1.1 cvs 5938: languages and the translation schemas are written using the same conventions
1.37 ! cvs 5939: as the structure and presentation schemas. In particular, the keywords of the
1.1 cvs 5940: T language (the stings between apostrophes in the following syntax rules) can
5941: be written in any combination of upper-case and lower-case letters, but
5942: identifiers created by the programmer must always be written in the same
1.18 cvs 5943: way.</p>
1.1 cvs 5944:
1.18 cvs 5945: <div class="subsection">
1.37 ! cvs 5946: <h3><a name="sectc521" id="sectc521">Organization of a translation
! 5947: schema</a></h3>
1.1 cvs 5948:
1.30 cvs 5949: <p>A translation schema is begun by the <tt>TRANSLATION</tt> keyword and is
1.37 ! cvs 5950: terminated by the <tt>END</tt> keyword. The <tt>TRANSLATION</tt> keyword is
! 5951: followed by the name of the generic structure for which a translation is
! 5952: being defined and a semicolon. This name must be identical to the name which
1.18 cvs 5953: appears after the <tt>STRUCTURE</tt> keyword in the corresponding structure
5954: schema.</p>
1.30 cvs 5955:
5956: <p>After this declaration of the structure, the following material appears in
1.18 cvs 5957: order:</p>
5958: <ul>
1.30 cvs 5959: <li>the length of lines produced by the translation,</li>
5960: <li>the character delimiting the end of the line,</li>
5961: <li>the character string which the translator will insert if it must
5962: line-break the translated text,</li>
1.37 ! cvs 5963: <li>declarations of
1.30 cvs 5964: <ul>
5965: <li>buffers,</li>
5966: <li>counters,</li>
5967: <li>constants,</li>
5968: <li>variables,</li>
5969: </ul>
5970: </li>
5971: <li>translation rules associated with element types,</li>
5972: <li>translation rules associated with attributes,</li>
5973: <li>translation rules associated with specific presentation rules,</li>
5974: <li>translation rules associated with characters strings, symbols and
5975: graphical elements.</li>
1.18 cvs 5976: </ul>
1.30 cvs 5977:
1.37 ! cvs 5978: <p>Each of these sections is introduced by a keyword followed by a sequence
! 5979: of declarations. All of these sections are optional, expect for the
! 5980: translation rules associated with element types. Many <tt>TEXTTRANSLATE</tt>
! 5981: sections can appear, each defining the rules for translating character
! 5982: strings of a particular alphabet.</p>
1.18 cvs 5983: <pre> TransSchema ='TRANSLATION' ElemID ';'
1.1 cvs 5984: [ 'LINELENGTH' LineLength ';' ]
5985: [ 'LINEEND' CHARACTER ';' ]
5986: [ 'LINEENDINSERT' STRING ';' ]
5987: [ 'BUFFERS' BufferSeq ]
5988: [ 'COUNTERS' CounterSeq ]
5989: [ 'CONST' ConstSeq ]
5990: [ 'VAR' VariableSeq ]
5991: 'RULES' ElemSeq
5992: [ 'ATTRIBUTES' AttrSeq ]
5993: [ 'PRESENTATION' PresSeq ]
1.30 cvs 5994: < 'TEXTTRANSLATE' TextTransSeq >
1.1 cvs 5995: [ 'SYMBTRANSLATE' TransSeq ]
5996: [ 'GRAPHTRANSLATE' TransSeq ]
1.18 cvs 5997: 'END' .</pre>
5998: </div>
1.1 cvs 5999:
1.18 cvs 6000: <div class="subsection">
1.37 ! cvs 6001: <h3><a name="sectc522" id="sectc522">Line length</a></h3>
1.1 cvs 6002:
1.30 cvs 6003: <p>If a <tt>LINELENGTH</tt> instruction is present after the structure
1.37 ! cvs 6004: declaration, the translator divides the text it produces into lines, each
! 6005: line having a length less than or equal to the integer which follows the
! 6006: <tt>LINELENGTH</tt> keyword. This maximum line length is expressed as a
! 6007: number of characters. The end of the line is marked by the character defined
! 6008: by the <tt>LINEEND</tt> instruction. When the translator breaks the lines on
1.1 cvs 6009: a space character in generated text, this space will be replaced by the
1.18 cvs 6010: character string defined by the <tt>LINEENDINSERT</tt> instruction.</p>
1.30 cvs 6011:
6012: <p>If the <tt>LINEEND</tt> instruction is not defined then the linefeed
6013: character (octal code 12) is used as the default line end character. If the
1.18 cvs 6014: <tt>LINEENDINSERT</tt> instruction is not defined, the linefeed character is
1.37 ! cvs 6015: inserted at the end of the produced lines. If there is no <tt>LINELENGTH</tt>
! 6016: instruction, the translated text is not divided into lines. Otherwise, if the
1.1 cvs 6017: translation rules generate line end marks, these marks remain in the
6018: translated text, but the length of the lines is not controlled by the
1.18 cvs 6019: translator.</p>
6020: <pre> LineLength = NUMBER .</pre>
1.30 cvs 6021:
1.18 cvs 6022: <blockquote class="example">
1.30 cvs 6023: <p><strong>Example:</strong></p>
6024:
6025: <p>To limit the lines produced by the translator to a length of 80
6026: characters, the following rule is written at the beginning of the
6027: translation schema.</p>
6028: <pre>LineLength 80;</pre>
1.18 cvs 6029: </blockquote>
6030: </div>
1.1 cvs 6031:
1.18 cvs 6032: <div class="subsection">
1.37 ! cvs 6033: <h3><a name="sectc523" id="sectc523">Buffers</a></h3>
1.1 cvs 6034:
1.37 ! cvs 6035: <p>A buffer is a unit of memory managed by the translator, which can either
1.18 cvs 6036: contain text read from the terminal during the translation (see the <a
6037: href="#sectc5212"><tt>Read</tt> rule</a>), or the name of the last picture
1.1 cvs 6038: (bit-map) encountered by the translator in its traversal of the document.
1.2 cvs 6039: Remember the pictures are stored in files that are separate for the document
1.1 cvs 6040: files and that the canonical form contains only the names of the files in
1.18 cvs 6041: which the pictures are found.</p>
1.30 cvs 6042:
1.37 ! cvs 6043: <p>Thus, there are two types of buffers: buffers for reading from the
1.30 cvs 6044: terminal (filled by the <tt>Read</tt> rule) and the buffer of picture names
1.37 ! cvs 6045: (containing the name of the last picture encountered). A translation schema
1.30 cvs 6046: can use either type, one or several read buffers and one (and only one)
6047: picture name buffer.</p>
6048:
6049: <p>If any buffers are used, the <tt>BUFFERS</tt> keyword must be present,
1.37 ! cvs 6050: followed by declarations of every buffer used in the translation schema. Each
! 6051: buffer declaration is composed only of the name of the buffer, chosen freely
! 6052: by the programmer. The picture name buffer is identified by the
! 6053: <tt>Picture</tt> keyword, between parentheses, following the buffer name. The
! 6054: <tt>Picture</tt> keyword may only appear once. Each buffer declaration is
1.18 cvs 6055: terminated by a semicolon.</p>
1.30 cvs 6056: <pre> BufferSeq = Buffer < Buffer > .
1.1 cvs 6057: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
1.18 cvs 6058: BufferID = NAME .</pre>
1.30 cvs 6059:
1.18 cvs 6060: <blockquote class="example">
1.30 cvs 6061: <p><strong>Example:</strong></p>
6062:
6063: <p>The following buffer declarations create a picture name buffer named
1.37 ! cvs 6064: <tt>pictureName</tt> and a read buffer named <a name="destname"
! 6065: id="destname"><tt>DestName</tt></a>:</p>
1.30 cvs 6066: <pre>BUFFERS
1.18 cvs 6067: pictureName (Picture); DestName;</pre>
6068: </blockquote>
6069: </div>
1.1 cvs 6070:
1.18 cvs 6071: <div class="subsection">
1.37 ! cvs 6072: <h3><a name="sectc524" id="sectc524">Counters</a></h3>
1.30 cvs 6073:
6074: <p>Certain translation rules generate text that varies according to the
1.37 ! cvs 6075: context of the element to which the rules apply. Variable text is defined
1.30 cvs 6076: either in the <a href="#sectc526"><tt>VAR</tt> section</a> of the translation
6077: schema or in the rule itself (see the <tt>Create</tt> and <tt>Write</tt>
1.37 ! cvs 6078: rules). Both types of definition rely on counters for the calculation of
1.30 cvs 6079: variable material.</p>
6080:
6081: <p>There are two types of counter: counters whose value is explicitely
6082: computed by applying <a href="#sectc5221"><tt>Set</tt> and <tt>Add</tt>
6083: rules</a>, and counters whose value is computed by a function associated with
6084: the counter. Those functions allow the same calculations as can be used in
1.37 ! cvs 6085: presentation schemas. As in a presentation schema, counters must be defined
! 6086: in the <tt>COUNTERS</tt> section of the translation schema before they are
1.30 cvs 6087: used.</p>
6088:
6089: <p>When counters are used in a translation schema, the <tt>COUNTERS</tt>
1.37 ! cvs 6090: keyword is followed by the declarations of every counter used. Each
! 6091: declaration is composed of the counter's name possibly followed by a colon
! 6092: and the counting function to be used for the counter. The declaration is
1.30 cvs 6093: terminated by a semi-colon. If the counter is explicitely computed by
6094: <tt>Set</tt> and <tt>Add</tt> rules, no counting function is indicated. If a
6095: counting function is indicated, <tt>Set</tt> and <tt>Add</tt> rules cannot be
6096: applied to that counter.</p>
1.1 cvs 6097:
1.30 cvs 6098: <p>The counting function indicates how the counter's value will be computed.
1.18 cvs 6099: Three functions are available: <tt>Rank</tt>, <tt>Rlevel</tt>, and
6100: <tt>Set</tt>.</p>
6101: <ul>
1.30 cvs 6102: <li><tt>Rank of ElemID</tt> indicates that the counter's value is the rank
6103: of the element of type <tt>ElemID</tt> which encloses the element for
1.37 ! cvs 6104: which the counter is being evaluated. For the purposes of this function,
! 6105: an element of type <tt>ElemID</tt> is considered to enclose itself. This
! 6106: function is primarily used when the element of type <tt>ElemID</tt> is
1.30 cvs 6107: part of an aggregate or list, in which case the counter's value is the
1.37 ! cvs 6108: element's rank in its list or aggregate. Note that, unlike the
! 6109: <tt>Rank</tt> function for presentation schemas, the <tt>Page</tt>
! 6110: keyword cannot be used in place of the <tt>ElemID</tt>.
! 6111: <p>The type name <tt>ElemID</tt> can be followed by an integer. That
! 6112: number represents the relative level, among the ancestors of the
! 6113: concerned element, of the element whose rank is asked. If that relative
! 6114: level <i>n</i> is unsigned, the <i>n<sup>th</sup></i> element of type
! 6115: <tt>ElemID</tt> encountered when travelling the logical structure from
! 6116: the root to the concerned element is taken into account. If the relative
1.30 cvs 6117: level is negative, the logical structure is travelled in the other
6118: direction, from the concerned element to the root.</p>
6119: </li>
6120: <li><tt>Rlevel of ElemID</tt> indicates that the counter's values is the
6121: relative level in the tree of the element for which the counter is being
6122: evaluated. The counter counts the number of elements of type
6123: <tt>ElemID</tt> which are found on the path between the root of the
6124: document's logical structure tree and the element (inclusive).</li>
6125: <li><tt>Set n on Type1 Add m on Type2</tt> indicates that the counter's
1.37 ! cvs 6126: value is calculated as follows: in traversing the document from the
1.30 cvs 6127: beginning to the element for which the counter is being evaluated, the
6128: counter is set to the value <tt>n</tt> each time a <tt>Type1</tt> element
6129: is encountered and is incremented by the amount <tt>m</tt> each time a
1.37 ! cvs 6130: <tt>Type2</tt> element is encountered. The initial value <tt>n</tt> and
1.30 cvs 6131: the increment <tt>m</tt> are integers.</li>
6132: </ul>
6133:
6134: <p>As in a presentation schema, the <tt>Rank</tt> and <tt>Set</tt> functions
1.37 ! cvs 6135: can be modified by a numeric attribute which changes their initial value.
! 6136: This is indicated by the <tt>Init</tt> keyword followed by the numeric
! 6137: attribute's name. The <tt>Set</tt> function takes the value of the attribute
! 6138: instead of the <tt>InitValue</tt> (<tt>n</tt>). For the <tt>Rank</tt>
! 6139: function, the value of the attribute is considered to be the rank of the
! 6140: first element of the list (rather than the normal value of 1). Subsequent
! 6141: items in the list have their ranks shifted accordingly. In both cases, the
! 6142: attribute must be numeric and must be a local attribute of the root of the
! 6143: document itself.</p>
1.30 cvs 6144: <pre> CounterSeq = Counter < Counter > .
1.1 cvs 6145: Counter = CounterID [ ':' CounterFunc ] ';' .
6146: CounterID = NAME .
6147: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
6148: [ 'Init' AttrID ] /
6149: 'Rlevel' 'of' ElemID /
6150: 'Set' InitValue 'On' ElemID
6151: 'Add' Increment 'On' ElemID
6152: [ 'Init' AttrID ] .
6153: SLevelAsc = [ '-' ] LevelAsc .
6154: LevelAsc = NUMBER .
6155: InitValue = NUMBER .
6156: Increment = NUMBER .
6157: ElemID = NAME .
1.18 cvs 6158: AttrID = NAME .</pre>
1.30 cvs 6159:
1.18 cvs 6160: <blockquote class="example">
1.30 cvs 6161: <p><strong>Example:</strong></p>
6162:
6163: <p>If the body of a chapter is defined in the structure schema by:</p>
6164: <pre>Chapter_Body = LIST OF
1.1 cvs 6165: (Section = BEGIN
6166: Section_Title = Text;
6167: Section_Body = BEGIN
6168: Paragraphs;
6169: Section;
6170: END;
6171: END
1.18 cvs 6172: );</pre>
1.30 cvs 6173:
6174: <p>(sections are defined recursively), a counter can be defined giving the
1.37 ! cvs 6175: <a name="sectnum" id="sectnum">number of a section</a> within its level in
! 6176: the hierarchy:</p>
1.30 cvs 6177: <pre>COUNTERS
1.18 cvs 6178: SectionNumber : Rank of Section;</pre>
1.30 cvs 6179:
6180: <p>A counter holding the hierarchic level of a section:</p>
6181: <pre> SectionLevel : Rlevel of Section;</pre>
6182:
1.37 ! cvs 6183: <p>A <a name="uniquenum" id="uniquenum">counter</a> which sequentially
! 6184: numbers all the document's sections, whatever their hierarchic level:</p>
1.30 cvs 6185: <pre> UniqueSectNum : Set 0 on Document Add 1 on Section;</pre>
1.18 cvs 6186: </blockquote>
6187: </div>
1.1 cvs 6188:
1.18 cvs 6189: <div class="subsection">
1.37 ! cvs 6190: <h3><a name="sectc525" id="sectc525">Constants</a></h3>
1.1 cvs 6191:
1.30 cvs 6192: <p>A common feature of translation rules is the generation of constant text.
1.37 ! cvs 6193: This text can be defined in the rule that generates it (see for example the
! 6194: <a href="#sectc5210"><tt>Create</tt></a> and <a
1.18 cvs 6195: href="#sectc5211"><tt>Write</tt></a> rules); but it can also be defined once
6196: in the constant declaration section and used many times in different rules.
1.37 ! cvs 6197: The latter option is preferable when the same text is used in several rules
! 6198: or several <a href="#sectc526">variables</a>.</p>
1.30 cvs 6199:
6200: <p>The <tt>CONST</tt> keyword begins the constant declaration section of the
1.37 ! cvs 6201: translation schema. It must be omitted if no constants are declared. Each
! 6202: constant declaration is composed of the constant name, an equals sign, and
! 6203: the constant's value, which is a character string between apostrophes. A
! 6204: constant declaration is terminated by a semicolon.</p>
1.30 cvs 6205: <pre> ConstSeq = Const < Const > .
1.1 cvs 6206: Const = ConstID '=' ConstValue ';' .
6207: ConstID = NAME .
1.18 cvs 6208: ConstValue = STRING .</pre>
1.30 cvs 6209:
1.18 cvs 6210: <blockquote class="example">
1.37 ! cvs 6211: <p><strong><a name="levelexample"
! 6212: id="levelexample">Example:</a></strong></p>
1.30 cvs 6213:
6214: <p>The following rule assigns the name <tt>TxtLevel</tt> to the character
6215: string ``Level'':</p>
6216: <pre>CONST
1.18 cvs 6217: TxtLevel = 'Level';</pre>
6218: </blockquote>
6219: </div>
1.1 cvs 6220:
1.18 cvs 6221: <div class="subsection">
1.37 ! cvs 6222: <h3><a name="sectc526" id="sectc526">Variables</a></h3>
1.1 cvs 6223:
1.30 cvs 6224: <p>Variables allow to define variable text which is generated by the
1.37 ! cvs 6225: <tt>Create</tt> and <tt>Write</tt> rules. They are also used to define file
1.18 cvs 6226: names which are used in the <tt>Create</tt>, <tt>ChangeMainFile</tt>,
1.37 ! cvs 6227: <tt>RemoveFile</tt>, and <tt>Indent</tt> rules. Variables can be defined
1.18 cvs 6228: either in the <tt>VAR</tt> section of the translation schema or directly in
1.37 ! cvs 6229: the rules which use them. Variables that define file names must be declared
1.18 cvs 6230: in the <tt>VAR</tt> section, and when the same variable is used several times
6231: in the translation schema, it makes sense to define it globally in the
1.37 ! cvs 6232: <tt>VAR</tt> section. This section is only present if at least one variable
1.18 cvs 6233: is defined globally.</p>
1.30 cvs 6234:
6235: <p>After the <tt>VAR</tt> keyword, each global variable is defined by its
6236: name, a colon separator and a sequence of functions (at least one function).
1.37 ! cvs 6237: Each variable definition is terminated by a semicolon. Functions determine
! 6238: the different parts which together give the value of the variable. The value
! 6239: is obtained by concatenating the strings produced by each of the functions.
! 6240: Seven types of functions are available. Each variable definition may use any
! 6241: number of functions of each type.</p>
1.18 cvs 6242: <ul>
1.30 cvs 6243: <li>The function <tt>Value(Counter)</tt>returns a string representing the
6244: value taken by the counter when it is evaluated for the element in whose
1.37 ! cvs 6245: rule the variable is used. The counter must have been declared in the
! 6246: <tt>COUNTERS</tt> section of the translation schema. When the counter is
1.30 cvs 6247: expressed in arabic numerals, the counter name can be followed by a colon
6248: and an integer indicating a minimum length (number of characters) for the
1.37 ! cvs 6249: string; if the counter's value is normally expressed with fewer
! 6250: characters than the required minimum, zeroes are added to the front of
! 6251: the string to achieve the minimum length.
1.30 cvs 6252: <p>By default, the counter value is written in arabic digits. If another
6253: representation of that value is needed, the counter name must be followed
6254: by a comma and one of the following keywords:</p>
6255: <ul>
6256: <li><tt>Arabic</tt>: arabic numerals (default value),</li>
6257: <li><tt>LRoman</tt>: lower-case roman numerals,</li>
6258: <li><tt>URoman</tt>: upper-case roman numerals,</li>
6259: <li><tt>Uppercase</tt>: upper-case letter,</li>
6260: <li><tt>Lowercase</tt>: lower-case letter.</li>
6261: </ul>
6262: </li>
6263: <li>The function <tt>FileDir</tt>, without parameter, returns a string
6264: representing the name of the directory of the output file that has been
6265: given as a parameter to the translation program. The string includes a
6266: character '/' at the end.</li>
6267: <li>The function <tt>FileName</tt>, without parameter, returns a string
6268: representing the name of the output file that has been given as a
6269: parameter to the translation program. The file extension (the character
6270: string that terminate the file name, after a dot) is not part of that
6271: string.</li>
6272: <li>The function <tt>Extension</tt>, without parameter, returns a string
6273: representing the extension of the file name. That string is empty if the
6274: file name that has been given as a parameter to the translation program
6275: has no extension. If there is an extension, its first character is a
6276: dot.</li>
6277: <li>The function <tt>DocumentName</tt>, without parameter, returns a string
6278: representing the name of the document being translated.</li>
6279: <li>The function <tt>DocumentDir</tt>, without parameter, returns a string
6280: representing the directory containing the document being translated.</li>
6281: <li>The function formed by the name of a constant returns that constant's
6282: value.</li>
6283: <li>The function formed by a character string between apostrophes returns
6284: that string.</li>
1.37 ! cvs 6285: <li>The function formed by the name of a buffer returns the contents of
! 6286: that buffer. If the named buffer is the picture buffer, then the name of
! 6287: the last picture encountered is returned. Otherwise, the buffer is a read
1.31 cvs 6288: buffer and the value returned is text previously read from the terminal.
1.30 cvs 6289: If the buffer is empty (no picture has been encountered or the
6290: <tt>Read</tt> rule has not been executed for the buffer), then the empty
6291: string is returned.</li>
6292: <li>The function formed by an attribute name takes the value of the
1.37 ! cvs 6293: indicated attribute for the element to which the variable applies. If the
1.30 cvs 6294: element does not have that attribute, then the element's ancestor are
1.37 ! cvs 6295: searched toward the root of the tree. If one of the ancestors does have
! 6296: the attribute then its value is used. If no ancestors have the attribute,
1.30 cvs 6297: then the value of the function is the empty string.</li>
1.18 cvs 6298: </ul>
1.30 cvs 6299: <pre> VariableSeq = Variable < Variable > .
6300: Variable = VarID ':' Function < Function > ';' .
1.1 cvs 6301: VarID = NAME .
6302: Function ='Value' '(' CounterID [ ':' Length ]
6303: [ ',' CounterStyle ] ')' /
6304: 'FileDir' / 'FileName' / 'Extension' /
6305: 'DocumentName' / 'DocumentDir' /
6306: ConstID / CharString /
6307: BufferID / AttrID .
6308: Length = NUMBER .
6309: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
6310: 'Uppercase' / 'Lowercase' .
1.18 cvs 6311: CharString = STRING .</pre>
1.30 cvs 6312:
1.18 cvs 6313: <blockquote class="example">
1.30 cvs 6314: <p><strong>Example:</strong></p>
6315:
6316: <p>To create, at the beginning of each section of the translated document,
6317: text composed of the string ``Section'' followed by the section number, the
1.37 ! cvs 6318: following <a name="varsectexample" id="varsectexample">variable
! 6319: definition</a> might be used:</p>
1.30 cvs 6320: <pre>VAR
1.18 cvs 6321: SectionVar : 'Section' Value(SectionNumber);</pre>
1.30 cvs 6322:
6323: <p>(see the definition of <a
6324: href="#sectnum"><tt>SectionNumber</tt></a>).</p>
6325:
1.37 ! cvs 6326: <p>The following variable definition can be used to create, at the
! 6327: beginning of each section, the text ``Level'' followed by the hierarchical
! 6328: level of the section. It used the constant defined above.</p>
1.30 cvs 6329: <pre> LevelVar : TxtLevel Value(SectionLevel);</pre>
6330:
6331: <p>(see the definitions of <a href="#sectnum"><tt>SectionLevel</tt></a> and
6332: of <a href="#levelexample"><tt>TxtLevel</tt></a>).</p>
6333:
6334: <p>To generate the translation of each section in a different file (see <a
1.37 ! cvs 6335: href="#sectc5220">rule <tt>ChangeMainFile</tt></a>), the name of these
! 6336: files might be defined by the following variable:</p>
1.30 cvs 6337: <pre> VarOutpuFile : FileName Value(SectionNumber)
1.18 cvs 6338: Extension;</pre>
1.30 cvs 6339:
1.37 ! cvs 6340: <p>If <tt>output.txt</tt> is the name of the <a name="varoutputfile"
! 6341: id="varoutputfile">output file</a> specified when starting the translation
! 6342: program, translated sections are written in files <tt>output1.txt</tt>,
! 6343: <tt>output2.txt</tt>, etc.</p>
1.18 cvs 6344: </blockquote>
6345: </div>
6346:
6347: <div class="subsection">
1.37 ! cvs 6348: <h3><a name="sectc527" id="sectc527">Translating structure elements</a></h3>
1.18 cvs 6349:
1.30 cvs 6350: <p>The <tt>RULES</tt> keyword introduces the translation rules which will be
1.37 ! cvs 6351: applied to the various structured element types. Translation rules can be
! 6352: specified for each element type defined in the structure schema, including
! 6353: the base types defined implicitly, whose names are <tt>TEXT_UNIT</tt>,
1.18 cvs 6354: <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>, <tt>GRAPHIC_UNIT</tt> and
1.37 ! cvs 6355: <tt>PAGE_UNIT</tt>. But it is not necessary to specify rules for every
1.18 cvs 6356: defined type.</p>
1.30 cvs 6357:
1.37 ! cvs 6358: <p>If there are no translation rules for an element type, the elements that
! 6359: it contains (and which may have rules themselves) will still be translated,
! 6360: but the translator will produce nothing for the element itself. To make the
1.18 cvs 6361: translator completely ignore the content of an element the <a
6362: href="#sectc5217"><tt>Remove</tt> rule</a> must be used.</p>
1.30 cvs 6363:
6364: <p>The translation rules for an element type defined in the structure schema
6365: are written using the name of the type followed by a colon and the list of
1.37 ! cvs 6366: applicable rules. When the element type is a <a href="#sectd3285">mark
1.18 cvs 6367: pair</a>, but only in this case, the type name must be preceded by the
1.37 ! cvs 6368: <tt>First</tt> or <tt>Second</tt> keyword. This keyword indicates whether the
1.18 cvs 6369: rules that follow apply to the first or second mark of the pair.</p>
1.30 cvs 6370:
1.37 ! cvs 6371: <p>The list of rules can take several forms. It may be a simple
! 6372: non-conditional rule. It can also be formed by a condition followed by one or
! 6373: more simple rules. Or it can be a block of rules beginning with the
1.30 cvs 6374: <tt>BEGIN</tt> keyword and ending with the <tt>END</tt> keyword and a
1.37 ! cvs 6375: semicolon. This block of rules can contain one or more simple rules and/or
1.30 cvs 6376: one or more conditions, each followed by one or more simple rules.</p>
6377: <pre> ElemSeq = TransType < TransType > .
1.1 cvs 6378: TransType = [ FirstSec ] ElemID ':' RuleSeq .
6379: FirstSec = 'First' / 'Second' .
1.30 cvs 6380: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
1.1 cvs 6381: Rule = SimpleRule / ConditionBlock .
6382: ConditionBlock = 'IF' ConditionSeq SimpleRuleSeq .
1.30 cvs 6383: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.18 cvs 6384: SimpleRule .</pre>
6385: </div>
1.1 cvs 6386:
1.18 cvs 6387: <div class="subsection">
1.37 ! cvs 6388: <h3><a name="sectc528" id="sectc528">Conditional rules</a></h3>
1.1 cvs 6389:
1.30 cvs 6390: <p>In a translation schema, the translation rules are either associated with
1.37 ! cvs 6391: element types or with attribute values or with a specific presentation. They
1.1 cvs 6392: are applied by the translator each time an element of the corresponding type
6393: is encountered in the translated document or each time the attribute value is
6394: carried by an element or also, each time the specific translation is attached
1.37 ! cvs 6395: to an element. This systematic application of the rules can be relaxed: it is
! 6396: possible to add a condition to one or more rules, so that these rules are
! 6397: only applied when the condition is true.</p>
1.30 cvs 6398:
6399: <p>A condition begins with the keyword <tt>IF</tt>, followed by a sequence of
1.37 ! cvs 6400: elementary conditions. Elementary conditions are separated from each other by
! 6401: the <tt>AND</tt> keyword. If there is only one elementary condition, this
! 6402: keyword is absent. The rules are only applied if all the elementary
! 6403: conditions are true. The elementary condition can be negative; it is then
1.18 cvs 6404: preceded by the <tt>NOT</tt> keyword.</p>
1.30 cvs 6405:
6406: <p>When the translation rule(s) controlled by the condition apply to a
6407: reference element or a reference attribute, an elementary condition can also
1.37 ! cvs 6408: apply to element referred by this reference. The <tt>Target</tt> keyword is
! 6409: used for that purpose. It must appear before the keyword defining the
1.30 cvs 6410: condition type.</p>
6411:
6412: <p>Depending on their type, some conditions may apply either to the element
1.37 ! cvs 6413: with which they are associated, or to one of its ancestor. In the case of an
1.18 cvs 6414: ancestor, the key word <tt>Ancestor</tt> must be used, followed by</p>
6415: <ul>
1.30 cvs 6416: <li>either an integer which represents the number of levels in the tree
6417: between the element and the ancestor of interest,</li>
1.37 ! cvs 6418: <li>or the type name of the ancestor of interest. If that type is defined
1.30 cvs 6419: in a separate structure schema, the name of that schema must follow
6420: between parentheses.</li>
1.18 cvs 6421: </ul>
1.30 cvs 6422:
1.37 ! cvs 6423: <p>There is a special case for the parent element, which can be simply
! 6424: written <tt>Parent</tt> instead of <tt>Ancestor 1</tt>.</p>
1.30 cvs 6425:
6426: <p>Only conditions <tt>First</tt>, <tt>Last</tt>, <tt>Referred</tt>,
1.34 cvs 6427: <tt>Within</tt>, <tt>Attributes</tt>, <tt>Presentation</tt>, and those
6428: concerning an attribute or a specific presentation can apply to an ancestor.
6429: Conditions <tt>FirstRef</tt>, <tt>LastRef</tt>, <tt>ExternalRef</tt>,
6430: <tt>Alphabet</tt>, <tt>FirstAttr</tt>, <tt>LastAttr</tt>,
6431: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>,
6432: <tt>ReminderPage</tt>, <tt>Empty</tt> cannot be preceded by keywords
6433: <tt>Parent</tt> or <tt>Ancestor</tt>.</p>
1.30 cvs 6434:
1.37 ! cvs 6435: <p>In condition <tt>Referred</tt> and in the condition that applies to a
! 6436: named attribute, a symbol '<tt>*</tt>' can indicate that the condition is
! 6437: related only to the element itself. If this symbol is not present, not only
! 6438: the element is considered, but also its ancestor, at any level.</p>
1.30 cvs 6439:
6440: <p>The form of an elementary condition varies according to the type of
1.18 cvs 6441: condition.</p>
1.1 cvs 6442:
1.18 cvs 6443: <div class="subsubsection">
1.37 ! cvs 6444: <h4><a name="sectd5281" id="sectd5281">Conditions based on the logical
! 6445: position of the element</a></h4>
1.30 cvs 6446:
6447: <p>The condition can be on the position of the element in the document's
1.37 ! cvs 6448: logical structure tree. It is possible to test whether the element is the
1.30 cvs 6449: first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
6450: not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>).</p>
6451:
6452: <p>It is also possible to test if the element is contained in an element of a
1.18 cvs 6453: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). If that
1.1 cvs 6454: element type is defined in a structure schema which is not the one which
6455: corresponds to the translation schema, the type name of this element must be
6456: followed, between parentheses, by the name of the structure schema which
1.18 cvs 6457: defines it.</p>
1.30 cvs 6458:
6459: <p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
1.18 cvs 6460: condition is satisfied only if the <em>parent</em> element has the type
6461: indicated. If the word <tt>Immediately</tt> is missing, the condition is
6462: satisfied if any <em>ancestor</em> has the type indicated.</p>
1.30 cvs 6463:
6464: <p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.37 ! cvs 6465: type. It specifies the number of ancestors of the indicated type that must be
! 6466: present for the condition to be satisfied. If the keyword
1.18 cvs 6467: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
1.37 ! cvs 6468: element must have the indicated type. The integer <i>n</i> must be positive
! 6469: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
! 6470: maximum or minimum number of ancestors. If these symbols are missing, the
! 6471: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
1.30 cvs 6472: this number is missing, it is equivalent to > 0.</p>
6473:
1.37 ! cvs 6474: <p>If the condition applies to translation rules associated with an
! 6475: attribute, i.e. if it is in the <tt>ATTRIBUTES</tt> section of the
! 6476: presentation schema, the condition can be simply an element name. Translation
! 6477: rules are then executed only if the attribute is attached to an element of
! 6478: that type. The keyword <tt>NOT</tt> before the element name indicates that
! 6479: the translation rules must be executed only if the element is not of the type
! 6480: indicated.</p>
1.18 cvs 6481: </div>
1.1 cvs 6482:
1.18 cvs 6483: <div class="subsubsection">
1.37 ! cvs 6484: <h4><a name="sectd5282" id="sectd5282">Conditions on references</a></h4>
1.1 cvs 6485:
1.30 cvs 6486: <p>References may be taken into account in conditions, which can be based on
6487: the fact that the element, or one of its ancestors (unless symbol <tt>*</tt>
6488: is present), is designated by a at least one reference (<tt>Referred</tt>) or
1.37 ! cvs 6489: by none (<tt>NOT Referred</tt>). If the element or attribute to which the
1.1 cvs 6490: condition is attached is a reference, the condition can be based on the fact
6491: that it acts as the first reference to the designated element
1.18 cvs 6492: (<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>), or as a reference to
1.37 ! cvs 6493: an element located in another document (<tt>ExternalRef</tt>). Like all
1.18 cvs 6494: conditions, conditions on references can be inverted by the <tt>NOT</tt>
6495: keyword.</p>
6496: </div>
6497:
6498: <div class="subsubsection">
1.37 ! cvs 6499: <h4><a name="sectd5284" id="sectd5284">Conditions on the alphabets</a></h4>
1.1 cvs 6500:
1.30 cvs 6501: <p>The character string base type (and only this type) can use the condition
1.37 ! cvs 6502: <tt>Alphabet = a</tt> which indicates that the translation rule(s) should
! 6503: only apply if the alphabet of the character string is the one whose name
! 6504: appears after the equals sign (or is not, if there is a preceding
! 6505: <tt>NOT</tt> keyword). This condition cannot be applied to translation rules
! 6506: of an attribute.</p>
1.30 cvs 6507:
6508: <p>In the current implementation of Thot, the available alphabets are the
1.18 cvs 6509: <tt>Latin</tt> alphabet and the <tt>Greek</tt> alphabet.</p>
6510: </div>
1.1 cvs 6511:
1.18 cvs 6512: <div class="subsubsection">
1.37 ! cvs 6513: <h4><a name="sectd5285" id="sectd5285">Conditions on page breaks</a></h4>
1.1 cvs 6514:
1.30 cvs 6515: <p>The page break base type (and only this type) can use the following
1.18 cvs 6516: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>, and
1.37 ! cvs 6517: <tt>ReminderPage</tt>. The <tt>ComputedPage</tt> condition indicates that the
1.1 cvs 6518: translation rule(s) should apply if the page break was created automatically
1.37 ! cvs 6519: by Thot; the <tt>StartPage</tt> condition is true if the page break is
1.18 cvs 6520: generated before the element by the <tt>Page</tt> rule of the P language; the
6521: <tt>UserPage</tt> condition applies if the page break was inserted by the
1.37 ! cvs 6522: user; and the <tt>ReminderPage</tt> is applied if the page break is a
! 6523: reminder of page breaking.</p>
1.18 cvs 6524: </div>
1.1 cvs 6525:
1.18 cvs 6526: <div class="subsubsection">
1.37 ! cvs 6527: <h4><a name="sectd5286" id="sectd5286">Conditions on the element's
! 6528: content</a></h4>
1.1 cvs 6529:
1.37 ! cvs 6530: <p>The condition can be based on whether or not the element is empty. An
1.30 cvs 6531: element which has no children or whose leaves are all empty is considered to
1.37 ! cvs 6532: be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
1.30 cvs 6533: optionally preceded by the <tt>NOT</tt> keyword.</p>
1.18 cvs 6534: </div>
1.1 cvs 6535:
1.18 cvs 6536: <div class="subsubsection">
1.37 ! cvs 6537: <h4><a name="sectd5288" id="sectd5288">Conditions on the presence of specific
! 6538: presentation rules</a></h4>
1.30 cvs 6539:
6540: <p>The condition can be based on the presence or absence of specific
1.37 ! cvs 6541: presentation rules associated with the translated element, whatever the
! 6542: rules, their value or their number. This condition is expressed by the
! 6543: keyword <tt>Presentation</tt>, optionally preceded by the <tt>NOT</tt>
! 6544: keyword.</p>
1.18 cvs 6545: </div>
1.1 cvs 6546:
1.18 cvs 6547: <div class="subsubsection">
1.37 ! cvs 6548: <h4><a name="sectd5289" id="sectd5289">Conditions on the presence of logical
1.18 cvs 6549: attributes</a></h4>
1.30 cvs 6550:
6551: <p>In the same way, the condition can be based on the presence or absence of
1.1 cvs 6552: attributes associated with the translated elements, no matter what the
1.37 ! cvs 6553: attributes or their values. The <tt>Attributes</tt> keyword expresses this
1.18 cvs 6554: condition.</p>
6555: </div>
1.1 cvs 6556:
1.18 cvs 6557: <div class="subsubsection">
1.37 ! cvs 6558: <h4><a name="sectd52810" id="sectd52810">Conditions on logical
! 6559: attributes</a></h4>
1.1 cvs 6560:
1.30 cvs 6561: <p>If the condition appears in the translation rules of an attribute, the
1.37 ! cvs 6562: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate
! 6563: that the rules must only be applied if this attribute is the first attribute
! 6564: for the translated element or if it is the last (respectively). These
! 6565: conditions can also be inverted by the <tt>NOT</tt> keyword.</p>
! 6566:
! 6567: <p>Another type of condition can only be applied to the translation rules
! 6568: when the element being processed (or one of its ancestors if symbol
! 6569: <tt>*</tt> is missing) has a certain attribute, perhaps with a certain value
! 6570: or, in contrast, when the element does not have this attribute with this
! 6571: value. The condition is specified by writing the name of the attribute after
! 6572: the keyword <tt>IF</tt> or <tt>AND</tt>. The <tt>NOT</tt> keyword can be used
! 6573: to invert the condition. If the translation rules must be applied to any
! 6574: element which has this attribute (or does not have it, if the condition is
! 6575: inverted) no matter what the attribute's value, the condition is complete.
! 6576: If, in contrast, the condition applies to one or more values of the
! 6577: attribute, these are indicated after the name of the attribute, except for
! 6578: reference attributes which do not have values.</p>
! 6579:
! 6580: <p>The representation of the values of an <a name="relattr"
! 6581: id="relattr">attribute</a> in a condition depends on the attribute's type.
! 6582: For attributes with enumerated or textual types, the value (a name or
! 6583: character string between apostrophes, respectively) is simply preceded by an
! 6584: equals sign. For numeric attributes, the condition can be based on a single
! 6585: value or on a range of values. In the case of a unique value, this value (an
! 6586: integer) is simply preceded by an equals sign. Conditions based on ranges of
! 6587: values have several forms:</p>
1.18 cvs 6588: <ul>
1.30 cvs 6589: <li>all values less than a given value (the value is preceded by a ``less
6590: than'' sign).</li>
6591: <li>all values greater than a given value (the value is preceded by a
6592: ``greater than'' sign).</li>
1.37 ! cvs 6593: <li>all values falling in an interval, bounds included. The range of values
! 6594: is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>,
! 6595: where Minimum and Maximum are integers.</li>
1.18 cvs 6596: </ul>
1.30 cvs 6597:
1.37 ! cvs 6598: <p>All numeric values may be negative. The integer is simply preceded by a
1.30 cvs 6599: minus sign.</p>
6600:
6601: <p>Both local and global attributes can be used in conditions.</p>
1.18 cvs 6602: </div>
1.1 cvs 6603:
1.18 cvs 6604: <div class="subsubsection">
1.37 ! cvs 6605: <h4><a name="sectd52811" id="sectd52811">Conditions on specific presentation
! 6606: rules</a></h4>
1.1 cvs 6607:
1.30 cvs 6608: <p>It is possible to apply translation rules only when the element being
1.1 cvs 6609: processed has or does not have a specific presentation rule, possibly with a
1.37 ! cvs 6610: certain value. The condition is specified by writing the name of the
! 6611: presentation rule after the keyword <tt>IF</tt> or <tt>AND</tt>. The
! 6612: <tt>NOT</tt> keyword can be used to invert the condition. If the translation
! 6613: rules must be applied to any element which has this presentation rule (or
! 6614: does not have it, if the condition is inverted) no matter what the rule's
! 6615: value, the condition is complete. If, in contrast, the condition applies to
! 6616: one or more values of the rule, these are indicated after the name of the
1.18 cvs 6617: attribute.</p>
1.30 cvs 6618:
1.37 ! cvs 6619: <p>The representation of presentation rule values in a condition is similar
! 6620: to that for attribute values. The representation of these values depend on
! 6621: the type of the presentation rule. There are three categories of presentation
1.18 cvs 6622: rules:</p>
6623: <ul>
1.30 cvs 6624: <li>those taking numeric values (<tt>Size, Indent, LineSpacing,
6625: LineWeight</tt>),</li>
1.36 cvs 6626: <li>those with values taken from a predefined list (<tt>Adjust, Hyphenate,
6627: Style, Weight, Font, UnderLine, Thickness, LineStyle</tt>),</li>
1.30 cvs 6628: <li>those whose value is a name (<tt>FillPattern, Background,
6629: Foreground</tt>).</li>
1.18 cvs 6630: </ul>
1.30 cvs 6631:
6632: <p>For presentation rules which take numeric values, the condition can take a
1.37 ! cvs 6633: unique value or a range of values. In the case of a unique value, this value
1.1 cvs 6634: (an integer) is simply preceded by an equals sign. Conditions based on ranges
1.18 cvs 6635: of values have several forms:</p>
6636: <ul>
1.30 cvs 6637: <li>all values less than a given value (the value is preceded by a ``less
6638: than'' sign).</li>
6639: <li>all values greater than a given value (the value is preceded by a
6640: ``greater than'' sign).</li>
1.37 ! cvs 6641: <li>all values falling in an interval, bounds included. The range of values
! 6642: is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>,
! 6643: where Minimum and Maximum are integers.</li>
1.18 cvs 6644: </ul>
1.30 cvs 6645:
1.37 ! cvs 6646: <p>Values for the <tt>Indent</tt>rule may be negative. The integer is then
1.2 cvs 6647: simply preceded by a minus sign and represents how far the first line starts
1.18 cvs 6648: to the left of the other lines.</p>
1.30 cvs 6649:
6650: <p>For presentation rules whose values are taken from predefined lists, the
1.37 ! cvs 6651: value which satisfies the condition is indicated by an equals sign followed
! 6652: by the name of the value.</p>
1.30 cvs 6653:
1.37 ! cvs 6654: <p>For presentation rule whose values are names, the value which satisfies
! 6655: the condition is indicated by the equals sign followed by the value's name.
! 6656: The names of fill patterns (the <tt>FillPattern</tt> rule) and of colors (the
1.18 cvs 6657: <tt>Foreground</tt> and <tt>Background</tt> rules) known to Thot are the same
6658: as in the P language.</p>
1.30 cvs 6659:
6660: <p>The syntax of conditions based on the specific presentation is the same as
6661: the syntax used to express the <a href="#sectc5224">translation of specific
1.18 cvs 6662: presentation rules</a>.</p>
1.30 cvs 6663:
6664: <p>When a condition has only one rule, the condition is simply followed by
1.37 ! cvs 6665: that rule. If it has several rules, they are placed after the condition
1.30 cvs 6666: between the keywords <tt>BEGIN</tt> and <tt>END</tt>.</p>
1.18 cvs 6667: <pre> ConditionSeq = Condition [ 'AND' Condition ] .
1.1 cvs 6668: Condition = [ 'NOT' ] [ 'Target' ] Cond .
6669: Cond = CondElem / CondAscend .
6670: CondElem ='FirstRef' / 'LastRef' /
6671: 'ExternalRef' /
6672: 'Alphabet' '=' Alphabet /
6673: 'ComputedPage' / 'StartPage' /
6674: 'UserPage' / 'ReminderPage' /
6675: 'Empty' /
1.11 cvs 6676: ElemID /
1.1 cvs 6677: 'FirstAttr' / 'LastAttr' .
6678: CondAscend = [ Ascend ] CondOnAscend .
6679: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
6680: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
6681: CondRelLevel = NUMBER .
6682: CondOnAscend ='First' / 'Last' /
6683: 'Referred' /
6684: [ 'Immediately' ] 'Within' [ NumParent ]
6685: ElemID [ ExtStruct ] /
6686: 'Attributes' /
6687: AttrID [ RelatAttr ] /
6688: 'Presentation' /
1.34 cvs 6689: PresRule .
1.1 cvs 6690: NumParent = [ GreaterLess ] NParent .
1.30 cvs 6691: GreaterLess = '>' / '<' .
1.1 cvs 6692: NParent = NUMBER.
6693: ExtStruct = '(' ElemID ')' .
6694: Alphabet = NAME .
6695: RelatAttr ='=' Value /
1.30 cvs 6696: '>' [ '-' ] Minimum /
1.1 cvs 6697: '<' [ '-' ] Maximum /
6698: 'IN' '[' [ '-' ] MinInterval '..'
6699: [ '-' ] MaxInterval ']' .
6700: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
6701: Minimum = NUMBER .
6702: Maximum = NUMBER .
6703: MinInterval = NUMBER .
6704: MaxInterval = NUMBER .
6705: IntegerVal = NUMBER .
6706: TextVal = STRING .
1.18 cvs 6707: AttrValue = NAME .</pre>
1.30 cvs 6708:
1.18 cvs 6709: <blockquote class="example">
1.30 cvs 6710: <p><strong>Example:</strong></p>
6711:
6712: <p>Suppose that after each element of type Section_Title it is useful to
6713: produce the text <tt>\label{SectX}</tt> where <tt>X</tt> represents the
6714: section number, but only if the section is designated by one or more
1.37 ! cvs 6715: references in the document. The following conditional rule produces this
1.30 cvs 6716: effect:</p>
6717: <pre>RULES
1.1 cvs 6718: Section_Title :
6719: IF Referred
1.18 cvs 6720: Create ('\label{Sect' Value(UniqueSectNum) '}\12') After;</pre>
1.30 cvs 6721:
6722: <p>(the declaration of the <a href="#sectc5224"><tt>UniqueSectNum</tt>
1.37 ! cvs 6723: counter</a> is given above). The string <tt>\12</tt> represents a line
1.30 cvs 6724: break.</p>
1.18 cvs 6725: </blockquote>
1.30 cvs 6726:
1.18 cvs 6727: <blockquote class="example">
1.30 cvs 6728: <p><strong>Example:</strong></p>
6729:
1.37 ! cvs 6730: <p>Suppose that for elements of the Elmnt type it would be useful to
! 6731: produce a character indicating the value of the numeric attribute Level
! 6732: associated with the element: an ``A'' for all values of Level less than 3,
! 6733: a ``B'' for values between 3 and 10 and a ``C'' for values greater than 10.
! 6734: This can be achieved by writing the following rules for the Elmnt type:</p>
1.30 cvs 6735: <pre>RULES
1.1 cvs 6736: Elmnt :
6737: BEGIN
6738: IF Level < 3
6739: Create 'A';
6740: IF Level IN [3..10]
6741: Create 'B';
1.30 cvs 6742: IF Level > 10
1.1 cvs 6743: Create 'C';
1.18 cvs 6744: END;</pre>
6745: </blockquote>
6746: </div>
6747: </div>
1.1 cvs 6748:
1.18 cvs 6749: <div class="subsection">
1.37 ! cvs 6750: <h3><a name="sectc529" id="sectc529">Translation rules</a></h3>
1.1 cvs 6751:
1.37 ! cvs 6752: <p>Fifteen types of translation rules can be associated with element types
! 6753: and attribute values. They are the <tt>Create</tt>, <tt>Write</tt>,
1.18 cvs 6754: <tt>Read</tt>, <tt>Include</tt>, <tt>Get</tt>, <tt>Copy</tt>, <tt>Use</tt>,
1.31 cvs 6755: <tt>Remove</tt>, <tt>Ignore</tt>, <tt>NoTranslation</tt>,
6756: <tt>NoLineBreak</tt>, <tt>ChangeMainFile</tt>, <tt>RemoveFile</tt>,
1.37 ! cvs 6757: <tt>Set</tt>, <tt>Add</tt>, <tt>Indent</tt>, rules. Each rule has its own
1.31 cvs 6758: syntax, although they are all based on very similar models.</p>
1.18 cvs 6759: <pre> SimpleRule = 'Create' [ 'IN' VarID ] Object
1.1 cvs 6760: [ Position ] ';' /
6761: 'Write' Object [ Position ] ';' /
6762: 'Read' BufferID [ Position ] ';' /
6763: 'Include' File [ Position ] ';' /
6764: 'Get' [ RelPosition ] ElemID
6765: [ ExtStruct ]
6766: [ Position ] ';' /
6767: 'Copy' [ RelPosition ] ElemID
6768: [ ExtStruct ]
6769: [ Position ] ';' /
6770: 'Use' TrSchema [ 'For' ElemID ] ';' /
6771: 'Remove' ';' /
1.31 cvs 6772: 'Ignore' ';' /
1.1 cvs 6773: 'NoTranslation' ';' /
6774: 'NoLineBreak' ';' /
6775: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 6776: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 6777: 'Set' CounterID InitValue [ Position ] ';' /
6778: 'Add' CounterID Increment [ Position ] ';' /
1.25 cvs 6779: 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .</pre>
1.18 cvs 6780: </div>
6781:
6782: <div class="subsection">
1.37 ! cvs 6783: <h3><a name="sectc5210" id="sectc5210">The <tt>Create</tt> rule</a></h3>
1.18 cvs 6784:
1.30 cvs 6785: <p>The most frequently used rule is undoubtedly the <tt>Create</tt> rule,
6786: which generates fixed or variable text (called an <em>object</em>) in the
1.37 ! cvs 6787: output file. The generated text can be made to appear either before or after
! 6788: the content of the element to which the rule applies. The rule begins with
! 6789: the <tt>Create</tt> keyword, followed by a specifier for the object and a
! 6790: keyword (<tt>Before</tt> or <tt>After</tt>) indicating the position of the
! 6791: generated text (<a href="#sectc5222">before or after</a> the element's
! 6792: content). If the position is not indicated, the object will be generated
! 6793: before the element's content. This rule, like all translation rules, is
! 6794: terminated by a semicolon.</p>
1.30 cvs 6795:
6796: <p>The <tt>Create</tt> keyword can be followed by the <tt>IN</tt> keyword and
1.37 ! cvs 6797: by the name of a variable. This means that the text generated by the rule
1.30 cvs 6798: must not be written in the main output file, but in the file whose name is
1.18 cvs 6799: specified by the variable.</p>
1.30 cvs 6800:
6801: <p>This allows the translation program to generate text in different files
6802: during the same run. These files do not need to be explicitely declared or
6803: opened. They do not need to be closed either, but if they contain temporary
6804: data, they can be removed (see the <a href="#sectc5220a"><tt>RemoveFile</tt>
6805: rule</a>). As soon as the translation program executes a <tt>Create</tt> rule
6806: for a file that is not yet open, it opens the file. These files are closed
6807: when the translation is finished.</p>
1.18 cvs 6808: <pre> 'Create' [ 'IN' VarID ] Object
1.1 cvs 6809: [ Position ] ';'
6810: Object = ConstID / CharString /
6811: BufferID /
6812: VarID /
1.30 cvs 6813: '(' Function < Function > ')' /
1.21 cvs 6814: [ 'Translated' ] AttrID /
1.1 cvs 6815: 'Value' /
6816: 'Content' /
6817: 'Attributes' /
6818: 'Presentation' /
6819: 'RefId' /
6820: 'PairId' /
6821: 'FileDir' /
6822: 'FileName' /
6823: 'Extension' /
6824: 'DocumentName' /
6825: 'DocumentDir' /
6826: [ 'Referred' ] ReferredObject .
6827: Position ='After' / 'Before' .
6828:
6829: ReferredObject = VarID /
6830: ElemID [ ExtStruct ] /
6831: 'RefId' /
6832: 'DocumentName' /
1.18 cvs 6833: 'DocumentDir' .</pre>
1.30 cvs 6834:
6835: <p>The object to be generated can be:</p>
1.18 cvs 6836: <ul>
1.30 cvs 6837: <li>a constant string, specified by its name if it is declared in the
6838: schema's <tt>CONST</tt> section, or given directly as a value between
6839: apostrophes;</li>
6840: <li>the contents of a buffer, designated by the name of the buffer;</li>
6841: <li>a variable, designated by its name if it is declared in the translation
1.37 ! cvs 6842: schema's <tt>VAR</tt> section, or given directly between parentheses. The
1.30 cvs 6843: text generated is the value of that variable evaluated for the element to
6844: which the rule applies.</li>
6845: <li>the value of an attribute, if the element being translated has this
6846: attribute. The attribute is specified by its name. If it's a text
6847: attribute, it can be preceded by the <code>Translated</code> keyword,
6848: which causes the attribute value to be recoded using the text translation
6849: table defined by section <code><a
6850: href="#sectc5225">TEXTTRANSLATE</a></code>;</li>
1.37 ! cvs 6851: <li>the value of a specific presentation rule. This object can only be
1.30 cvs 6852: generated if the translation rule is for a <a href="#prestransl">specific
1.37 ! cvs 6853: presentation rule</a>. It is specified by the <tt>Value</tt> keyword;</li>
! 6854: <li>the element's content. That is, the content of the leaves of the
! 6855: subtree of the translated element. This is specified by the
1.30 cvs 6856: <tt>Content</tt> keyword;</li>
6857: <li>the translation of all attributes of the element (which is primarily
6858: used to apply the attribute translation rules <a
1.37 ! cvs 6859: href="#sectc5222">before</a> those of the element type). This is
1.30 cvs 6860: specified by the <tt>Attributes</tt> keyword.</li>
6861: <li>the translation of all of the element's specific presentation rules
6862: (which is primarily used to apply the translation rules for the specific
1.37 ! cvs 6863: presentation rules <a href="#sectc5222">before</a> those of the element
! 6864: or its attributes). This option is specified by the <tt>Presentation</tt>
1.30 cvs 6865: keyword;</li>
1.37 ! cvs 6866: <li>The value of the reference's identifier.<br />
! 6867: Thot associates a unique identifier with each element in a document. This
! 6868: identifier (called <em>reference's identifier</em> or <em>label</em>) is
! 6869: a character string containing the letter `L' followed by digits. Thot
! 6870: uses it in references for identifying the referred element.<br />
1.30 cvs 6871: The <tt>RefId</tt> keyword produces the reference's identifier of the
6872: element to which the translation rule is applied, or the reference's
6873: identifier of its first ancestor that is referred by a reference or that
6874: can be referred by a reference.</li>
1.37 ! cvs 6875: <li>the value of a mark pair's unique identifier. This may only be used for
1.30 cvs 6876: <a href="#sectd3285">mark pairs</a> and is indicated by the
6877: <tt>PairId</tt> keyword.</li>
6878: <li>the directory containing the file being generated (this string includes
1.37 ! cvs 6879: an ending '/', if it is not empty). This is indicated by the
1.30 cvs 6880: <tt>FileDir</tt> keyword.</li>
6881: <li>the name of the file being generated (only the name, without the
6882: directory and without the extension). This is indicated by the
6883: <tt>FileName</tt> keyword.</li>
6884: <li>the extension of the file being generated (this string starts with a
1.37 ! cvs 6885: dot, if it is not empty). This is indicated by the <tt>Extension</tt>
1.30 cvs 6886: keyword.</li>
1.37 ! cvs 6887: <li>the name of the document being translated. This is indicated by the
1.30 cvs 6888: <tt>DocumentName</tt> keyword.</li>
1.37 ! cvs 6889: <li>the directory containing the document being translated. This is
1.30 cvs 6890: indicated by the <tt>DocumentDir</tt> keyword.</li>
1.18 cvs 6891: </ul>
1.30 cvs 6892:
1.37 ! cvs 6893: <p>When the rule applies to a reference (an element or an attribute defined
! 6894: as a reference in the structure schema), it can generate a text related to
! 6895: the element referred by that reference. The rule name is then followed by the
1.18 cvs 6896: <tt>Referred</tt> keyword and a specification of the object to be generated
1.37 ! cvs 6897: for the referred element. This specification can be:</p>
1.18 cvs 6898: <ul>
1.37 ! cvs 6899: <li>the name of a variable. The rule generates the value of that variable,
1.30 cvs 6900: computed for the referred element.</li>
1.37 ! cvs 6901: <li>an element type. The rule generates the translation of the element of
! 6902: that type, which is in the subtree of the referred element. If this
1.30 cvs 6903: element is not defined in the structure schema which corresponds to the
6904: translation schema (that is, an object defined in another schema), the
6905: element's type name must be followed by the name of its structure schema
6906: between parentheses.</li>
1.37 ! cvs 6907: <li>the <tt>RefId</tt> keyword. The rule generates the reference's
1.30 cvs 6908: identifier of the referred element.</li>
1.37 ! cvs 6909: <li>the <tt>DocumentName</tt> keyword. The rule generates the name of the
1.30 cvs 6910: document to which the referred element belongs.</li>
1.37 ! cvs 6911: <li>the <tt>DocumentDir</tt> keyword. The rule generates the name of the
1.30 cvs 6912: directory that contains the document of the referred element.</li>
1.18 cvs 6913: </ul>
6914: </div>
1.1 cvs 6915:
1.18 cvs 6916: <div class="subsection">
1.37 ! cvs 6917: <h3><a name="sectc5211" id="sectc5211">The <tt>Write</tt> rule</a></h3>
1.1 cvs 6918:
1.37 ! cvs 6919: <p>The <tt>Write</tt> has the same syntax as the <tt>Create</tt> rule. It
1.30 cvs 6920: also produces the same effect, but the generated text is displayed on the
6921: user's terminal during the translation of the document, instead of being
1.37 ! cvs 6922: produced in the translated document. This is useful for helping the user keep
1.30 cvs 6923: track of the progress of the translation and for prompting the user on the
6924: terminal for input required by the <tt>Read</tt> rule.</p>
1.18 cvs 6925: <pre> 'Write' Object [ Position ] ';'</pre>
1.30 cvs 6926:
6927: <p>Notice: if the translator is launched by the editor (by the ``Save as''
1.18 cvs 6928: command), messages produced by the <tt>Write</tt> rule are not displayed.</p>
1.30 cvs 6929:
1.18 cvs 6930: <blockquote class="example">
1.30 cvs 6931: <p><strong>Example:</strong></p>
6932:
6933: <p>To make the translator display the number of each section being
6934: translated on the user's terminal, the following rule is specified for the
6935: <tt>Section</tt> element type:</p>
6936: <pre>Section : BEGIN
1.1 cvs 6937: Write VarSection;
6938: ...
1.18 cvs 6939: END;</pre>
1.30 cvs 6940:
6941: <p>(see <a href="#varsectexample">above</a> for the definition of the
6942: <tt>VarSection</tt> variable).</p>
6943:
6944: <p>To display text on the terminal before issuing a read operation with the
6945: <tt>Read</tt> rule, the following rule is used:</p>
6946: <pre>BEGIN
1.1 cvs 6947: Write 'Enter the name of the destination: ';
6948: ...
1.18 cvs 6949: END;</pre>
6950: </blockquote>
6951: </div>
6952:
6953: <div class="subsection">
1.37 ! cvs 6954: <h3><a name="sectc5212" id="sectc5212">The <tt>Read</tt> rule</a></h3>
1.18 cvs 6955:
1.30 cvs 6956: <p>The <tt>Read</tt> rule reads text from the terminal during the translation
6957: of the document and saves the text read in one of the buffers declared in the
1.37 ! cvs 6958: <tt>BUFFERS</tt> section of the schema. The buffer to be used is indicated by
! 6959: its name, after the <tt>READ</tt> keyword. This name can be followed, as in
1.18 cvs 6960: the <tt>Create</tt> and <tt>Write</tt> rules, by a keyword indicating if the
6961: read operation must be performed <tt>Before</tt> or <tt>After</tt> the
1.37 ! cvs 6962: translation of the element's content. If this keyword is absent, the read
! 6963: operation is done beforehand. The text is read into the buffer and remains
1.5 cvs 6964: there until a rule using the same buffer - possibly the same rule - is
1.18 cvs 6965: applied.</p>
6966: <pre> 'Read' BufferID [ Position ] ';'</pre>
1.30 cvs 6967:
1.18 cvs 6968: <blockquote class="example">
1.30 cvs 6969: <p><strong>Example:</strong></p>
6970:
6971: <p>The following set of rules tells the user that the translator is waiting
6972: for the entry of some text, reads this text into a buffer and copies the
6973: text into the translated document.</p>
6974: <pre>BEGIN
1.1 cvs 6975: Write 'Enter the name of the destination: ';
6976: Read DestName;
6977: Create DestName;
6978: ...
1.18 cvs 6979: END;</pre>
1.30 cvs 6980:
6981: <p>(see <a href="#destname">above</a> the definition of
6982: <tt>DestName</tt>).</p>
1.18 cvs 6983: </blockquote>
6984: </div>
6985:
6986: <div class="subsection">
1.37 ! cvs 6987: <h3><a name="sectc5213" id="sectc5213">The <tt>Include</tt> rule</a></h3>
1.18 cvs 6988:
1.30 cvs 6989: <p>The <tt>Include</tt> rule, like the <tt>Create</tt> rule, is used to
1.37 ! cvs 6990: produce text in the translated document. It inserts constant text which is
! 6991: not defined in the translation schema, but is instead taken from a file. The
! 6992: file's name is specified after the <tt>Include</tt> keyword, either directly
! 6993: as a character string between apostrophes or as the name of one of the
! 6994: buffers declared in the <tt>BUFFERS</tt> section of the schema. In the latter
! 6995: case, the buffer is assumed to contain the file's name. This can be used when
! 6996: the included file's name is known only at the moment of translation. This
! 6997: only requires that the <tt>Include</tt> rule is preceded by a <tt>Read</tt>
! 6998: rule which puts the name of the file desired by the user into the buffer.</p>
1.30 cvs 6999:
7000: <p>Like the other rules, it is possible to specify whether the inclusion will
1.1 cvs 7001: occur before or after the element's content, with the default being before.
7002: The file inclusion is only done at the moment of translation, not during the
7003: compilation of the translation schema. Thus, the file to be included need not
7004: exist during the compilation, but it must be accessible at the time of
1.37 ! cvs 7005: translation. Its contents can also be modified between two translations, thus
1.1 cvs 7006: producing different results, even if neither the document or the translation
1.18 cvs 7007: schema are modified.</p>
1.30 cvs 7008:
7009: <p>During translation, the file to be included is searched for along the
7010: schema directory path (indicated by the environment variable
1.37 ! cvs 7011: <tt>THOTSCH</tt>). The file name is normally only composed of a simple name,
! 7012: without specification of a complete file path. However, if the filename
1.30 cvs 7013: starts with a '/', it is considered as an absolute path.</p>
1.18 cvs 7014: <pre> 'Include' File [ Position ] ';'
1.6 cvs 7015: File = FileName / BufferID .
1.18 cvs 7016: FileName = STRING .</pre>
1.30 cvs 7017:
1.18 cvs 7018: <blockquote class="example">
1.30 cvs 7019: <p><strong>Example:</strong></p>
7020:
1.37 ! cvs 7021: <p>Suppose that it is desirable to print documents of the Article class
! 7022: with a formatter which requires a number of declarations and definitions at
! 7023: the beginning of the file. The <tt>Include</tt>rule can be used to achieve
1.30 cvs 7024: this. All the declarations and definitions a replaced in a file called
7025: <tt>DeclarArt</tt> and then the <tt>Article</tt> element type is given the
7026: following rule:</p>
7027: <pre>Article : BEGIN
1.1 cvs 7028: Include 'DeclarArt' Before;
7029: ...
1.18 cvs 7030: END;</pre>
7031: </blockquote>
7032: </div>
7033:
7034: <div class="subsection">
1.37 ! cvs 7035: <h3><a name="sectc5214" id="sectc5214">The <tt>Get</tt> rule</a></h3>
1.18 cvs 7036:
1.30 cvs 7037: <p>The <tt>Get</tt> rule is used to change the order in which the elements
1.37 ! cvs 7038: appear in the translated document. More precisely, it produces the
1.30 cvs 7039: translation of a specified element before or after the translation of the
1.37 ! cvs 7040: content of the element to which the rule applies. The <tt>Before</tt> and
1.30 cvs 7041: <tt>After</tt> keywords are placed at the end of the rule to specify whether
7042: the operation should be performed before or after translation of the rule's
7043: element (the default is before). The type of the element to be moved must be
7044: specified after the <tt>Get</tt> keyword, optionally preceded by a keyword
7045: indicating where the element will be found in the logical structure of the
7046: document:</p>
1.18 cvs 7047: <dl>
1.30 cvs 7048: <dt><tt>Included</tt></dt>
7049: <dd>The element to be moved is the first element of the indicated type
7050: which is found inside the element to which the rule applies.</dd>
7051: <dt><tt>Referred</tt></dt>
7052: <dd>This keyword can only be used if the rule applies to a reference
1.37 ! cvs 7053: element. The element to be moved is either the element designated by
! 7054: the reference (if that element is of the specified type), or the first
1.30 cvs 7055: element of the desired type contained within the element designated by
7056: the reference.</dd>
7057: <dt>no keyword</dt>
1.37 ! cvs 7058: <dd><p>The translator takes the first element of the indicated type from
! 7059: among the siblings of the rule's element. This is primarily used to
! 7060: change the order of the components of an aggregate.</p>
1.30 cvs 7061: </dd>
1.18 cvs 7062: </dl>
1.30 cvs 7063:
7064: <p>If the element to be moved is defined in a structure schema which is not
7065: the one which corresponds to the translation schema (in the case of an
7066: included object with a different schema), the type name of this element must
7067: be followed, between parentheses, by the name of the structure schema which
1.18 cvs 7068: defines it.</p>
7069: <pre> 'Get' [ RelPosition ] ElemID
1.6 cvs 7070: [ ExtStruct ]
7071: [ Position ] ';' /
7072: RelPosition = 'Included' / 'Referred' .
1.18 cvs 7073: ExtStruct = '(' ElemID ')' .</pre>
1.30 cvs 7074:
7075: <p>The <tt>Get</tt> rule has no effect if the element which it is supposed to
1.37 ! cvs 7076: move has already been translated. Thus, the element will not be duplicated.
1.1 cvs 7077: It is generally best to associate the rule with the first element which will
1.37 ! cvs 7078: be encountered by the translator in its traversal of the document. Suppose an
1.18 cvs 7079: aggregate has two elements <tt>A</tt> and <tt>B</tt>, with <tt>A</tt>
1.37 ! cvs 7080: appearing first in the logical structure. To permute these two elements, a
1.18 cvs 7081: <tt>Get B before</tt> rule should be associated with the <tt>A</tt> element
1.37 ! cvs 7082: type, not the inverse. Similarly, a rule of the form <tt>Get Included X
1.18 cvs 7083: After</tt>, even though syntactically correct, makes no sense since, by the
1.1 cvs 7084: time it will be applied, after the translation of the contents of the element
1.18 cvs 7085: to which it is attached, the <tt>X</tt> element will already have been
7086: translated.</p>
7087: </div>
7088:
7089: <div class="subsection">
1.37 ! cvs 7090: <h3><a name="sectc5215" id="sectc5215">The <tt>Copy</tt> rule</a></h3>
1.18 cvs 7091:
1.30 cvs 7092: <p>Like the <tt>Get</tt> rule, the <tt>Copy</tt> rule generates the
7093: translation of a specified element, but it acts even if the element has
7094: already been translated and it allows to copy it or to translate it later.
7095: Both rules have the same syntax.</p>
1.18 cvs 7096: <pre> 'Copy' [ RelPosition ] ElemID
7097: [ ExtStruct ] [ Position ] ';'</pre>
7098: </div>
7099:
7100: <div class="subsection">
1.37 ! cvs 7101: <h3><a name="sectc5216" id="sectc5216">The <tt>Use</tt> rule</a></h3>
1.18 cvs 7102:
1.30 cvs 7103: <p>The <tt>Use</tt> rule specifies the translation schema to be applied to
1.37 ! cvs 7104: objects of a certain class that are part of the document. This rule only
1.1 cvs 7105: appears in the rules for the root element of the document (the first type
1.18 cvs 7106: defined after the <tt>STRUCT</tt> keyword in the structure schema) or the
1.1 cvs 7107: rules of an element defined by an external structure (by another structure
1.37 ! cvs 7108: schema). Also, the <tt>Use</tt> rule cannot be conditional.</p>
1.30 cvs 7109:
7110: <p>If the rule is applied to an element defined by an external structure, the
1.18 cvs 7111: <tt>Use</tt> keyword is simply followed by the name of the translation schema
1.37 ! cvs 7112: to be used for element constructed according to that external structure. If
1.1 cvs 7113: the rule is applied to the document's root element, it is formed by the
1.18 cvs 7114: <tt>Use</tt> keyword followed by the translation schema's name, the
7115: <tt>For</tt> keyword and the name of the external structure to which the
7116: indicated translation schema should be applied.</p>
7117: <pre> 'Use' TrSchema [ 'For' ElemID ] ';'
7118: TrSchema = NAME .</pre>
1.30 cvs 7119:
7120: <p>If no <tt>Use</tt> rule defines the translation schema to be used for an
1.1 cvs 7121: external structure which appears in a document, the translator asks the user,
7122: during the translation process, which schema should be used. Thus, it is not
1.18 cvs 7123: necessary to give the translation schema a <tt>Use</tt> rule for every
1.1 cvs 7124: external structure used, especially when the choice of translation schemas is
1.18 cvs 7125: to be left to the user.</p>
1.30 cvs 7126:
7127: <p>Notice: if the translator is launched by the editor (by the ``Save as''
1.18 cvs 7128: command), prompts are not displayed.</p>
1.30 cvs 7129:
1.18 cvs 7130: <blockquote class="example">
1.30 cvs 7131: <p><strong>Example:</strong></p>
7132:
7133: <p>The <tt>Article</tt> structure schema uses the <tt>Formula</tt> external
7134: structure, defined by another structure schema, for mathematical
7135: formulas:</p>
7136: <pre>STRUCTURE Article;
1.1 cvs 7137: ...
7138: STRUCT
7139: Article = ...
7140: ...
7141: Formula_in_text = Formula;
7142: Isolated_formula = Formula;
7143: ...
1.18 cvs 7144: END</pre>
1.30 cvs 7145:
7146: <p>Suppose that it would be useful to use the <tt>FormulaT</tt> translation
1.37 ! cvs 7147: schema for the formulas of an article. This can be expressed in two
1.30 cvs 7148: different ways in the <tt>Article</tt> class translation schema, using the
7149: rules:</p>
7150: <pre>RULES
1.1 cvs 7151: Article :
1.18 cvs 7152: Use FormulaT for Formula;</pre>
1.30 cvs 7153:
7154: <p>or:</p>
7155: <pre>RULES
1.1 cvs 7156: ...
7157: Formula :
1.18 cvs 7158: Use FormulaT;</pre>
7159: </blockquote>
7160: </div>
7161:
7162: <div class="subsection">
1.37 ! cvs 7163: <h3><a name="sectc5217" id="sectc5217">The <tt>Remove</tt> rule</a></h3>
1.18 cvs 7164:
1.37 ! cvs 7165: <p>The <tt>Remove</tt> rule indicates that nothing should be generated, in
! 7166: the translated document, for the content of the element to which the rule
! 7167: applies. The content of that element is simply ignored by the translator.
! 7168: This does not prevent the generation of text for the element itself, using
! 7169: the <tt>Create</tt> or <tt>Include</tt> rules, for example.</p>
1.30 cvs 7170:
7171: <p>The <tt>Remove</tt> rule is simply written with the <tt>Remove</tt>
7172: keyword. It is terminated, like all rules, by a semicolon.</p>
1.18 cvs 7173: <pre> 'Remove' ';'</pre>
7174: </div>
7175:
7176: <div class="subsection">
1.37 ! cvs 7177: <h3><a name="sectc5217a" id="sectc5217a">The <tt>Ignore</tt> rule</a></h3>
1.31 cvs 7178:
1.37 ! cvs 7179: <p>The <tt>Ignore</tt> rule indicates that nothing should be generated, in
! 7180: the translated document, for the element to which the rule applies. The whole
1.32 cvs 7181: element is simply ignored by the translator.</p>
1.31 cvs 7182:
7183: <p>The <tt>Ignore</tt> rule is simply written with the <tt>Ignore</tt>
7184: keyword. It is terminated, like all rules, by a semicolon.</p>
7185: <pre> 'Ignore' ';'</pre>
7186: </div>
7187:
7188: <div class="subsection">
1.37 ! cvs 7189: <h3><a name="sectc5218" id="sectc5218">The <tt>NoTranslation</tt>
! 7190: rule</a></h3>
1.18 cvs 7191:
1.30 cvs 7192: <p>The <tt>NoTranslation</tt> rule indicates to the translator that it must
1.37 ! cvs 7193: not translate the content of the leaves of the element to which it applies.
! 7194: In contrast to the <tt>Remove</tt> rule, it does not suppress the content of
! 7195: the element, but it inhibits the translation of character strings, symbols,
! 7196: and graphical elements contained in the element. These are retrieved so that
1.18 cvs 7197: after the translation of the document, the rules of the <a
7198: href="#sectc5225"><tt>TEXTTRANSLATE</tt>, <tt>SYMBTRANSLATE</tt> and
7199: <tt>GRAPHTRANSLATE</tt> sections</a> will not be applied to them.</p>
1.30 cvs 7200:
7201: <p>The <tt>NoTranslation</tt> rule is written with the <tt>NoTranslation</tt>
1.18 cvs 7202: keyword followed by a semicolon.</p>
7203: <pre> 'NoTranslation' ';'</pre>
7204: </div>
7205:
7206: <div class="subsection">
1.37 ! cvs 7207: <h3><a name="sectc5219" id="sectc5219">The <tt>NoLineBreak</tt> rule</a></h3>
1.18 cvs 7208:
1.30 cvs 7209: <p>The <tt>NoLineBreak</tt> rule indicates to the translator that it must not
1.1 cvs 7210: generate additional line breaks in the output produced for the element to
1.37 ! cvs 7211: which it applies. This is as if it was an <a href="#sectc522">instruction
1.18 cvs 7212: <tt>LINELENGTH 0;</tt></a> at the beginning of the translation schema, but
7213: only for the current element.</p>
1.30 cvs 7214:
7215: <p>The <tt>NoLineBreak</tt> rule is written with the <tt>NoLineBreak</tt>
7216: keyword followed by a semicolon.</p>
1.18 cvs 7217: <pre> 'NoLineBreak' ';'</pre>
7218: </div>
1.1 cvs 7219:
1.18 cvs 7220: <div class="subsection">
1.37 ! cvs 7221: <h3><a name="sectc5220" id="sectc5220">The <tt>ChangeMainFile</tt>
! 7222: rule</a></h3>
1.1 cvs 7223:
1.30 cvs 7224: <p>When the translation program starts, it opens a main output file, whose
1.37 ! cvs 7225: name is given as a parameter of the translator. All <a
! 7226: href="#sectc5210"><tt>Create</tt> rules</a> without explicit indication of
! 7227: the output file write sequentially in this file. When a
! 7228: <tt>ChangeMainFile</tt> rule is executed, the main output file is closed and
! 7229: it is replaced by a new one, whose name is specified in the
! 7230: <tt>ChangeMainFile</tt> rule. The <tt>Create</tt> rules without indication of
! 7231: the output file that are then executed write in this new file. Several
! 7232: <tt>ChangeMainFile</tt> rules can be executed during the same translation,
! 7233: for dividing the main output into several files.</p>
1.30 cvs 7234:
7235: <p>This rule is written with the <tt>ChangeMainFile</tt> keyword followed by
7236: the name of a variable that specifies the name of the new main file. The
1.37 ! cvs 7237: keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the
! 7238: rule to specify whether the operation should be performed before or after
! 7239: translation of the rule's element (the default is before). This rule, like
! 7240: all translation rules, is terminated by a semicolon.</p>
1.18 cvs 7241: <pre> 'ChangeMainFile' VarID [ Position ] ';'</pre>
1.30 cvs 7242:
1.18 cvs 7243: <blockquote class="example">
1.30 cvs 7244: <p><strong>Example:</strong></p>
7245:
7246: <p>To generate the translation of each section in a different file, the
1.37 ! cvs 7247: following rule can be associated with type <tt>Section</tt>. That rule uses
1.30 cvs 7248: the <a href="#varoutputfile"><tt>VarOutpuFile</tt> variable</a> defined
7249: above.</p>
7250: <pre> Section:
1.18 cvs 7251: ChangeMainFile VarOutpuFile Before;</pre>
1.30 cvs 7252:
7253: <p>If <tt>output.txt</tt> is the name of the output file specified when
7254: starting the translation program, translated sections are written in files
7255: <tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>
1.18 cvs 7256: </blockquote>
7257: </div>
1.1 cvs 7258:
1.18 cvs 7259: <div class="subsection">
1.37 ! cvs 7260: <h3><a name="sectc5220a" id="sectc5220a">The <tt>RemoveFile</tt> rule</a></h3>
1.14 cvs 7261:
1.37 ! cvs 7262: <p>Files may be used for storing temporary data that are no longer needed
! 7263: when the translation of a document is complete. These files may be removed by
! 7264: the <tt>RemoveFile</tt> rule.</p>
1.30 cvs 7265:
7266: <p>This rule is written with the <tt>RemoveFile</tt> keyword followed by the
1.37 ! cvs 7267: name of a variable that specifies the name of the file to be removed. The
! 7268: keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the
! 7269: rule to specify whether the operation should be performed before or after
! 7270: translation of the rule's element (the default is before). This rule, like
1.30 cvs 7271: all translation rules, is terminated by a semicolon.</p>
1.18 cvs 7272: <pre> 'RemoveFile' VarID [ Position ] ';'</pre>
7273: </div>
7274:
7275: <div class="subsection">
1.37 ! cvs 7276: <h3><a name="sectc5221" id="sectc5221">The <tt>Set</tt> and <tt>Add</tt>
! 7277: rules</a></h3>
1.18 cvs 7278:
1.37 ! cvs 7279: <p>The <tt>Set</tt> and <tt>Add</tt> rules are used for modifying the value
! 7280: of counters that have no <a href="#sectc524">counting function</a>. Only this
1.18 cvs 7281: type of counter can be used in the <tt>Set</tt> and <tt>Add</tt> rules.</p>
1.30 cvs 7282:
7283: <p>Both rules have the same syntax: after the keyword <tt>Set</tt> or
1.18 cvs 7284: <tt>Add</tt> appear the counter name and the value to assign to the counter
7285: (<tt>Set</tt> rule) or the value to be added to the counter (<tt>Add</tt>
1.37 ! cvs 7286: rule). The keyword <tt>Before</tt> or <tt>After</tt> can follow that value to
1.1 cvs 7287: indicate when the rule must be applied: before or after the element's content
1.37 ! cvs 7288: is translated. By default, <tt>Before</tt> is assumed. A semicolon terminates
1.18 cvs 7289: the rule.</p>
7290: <pre> 'Set' CounterID InitValue [ Position ] ';' /
7291: 'Add' CounterID Increment [ Position ] ';'</pre>
7292: </div>
7293:
7294: <div class="subsection">
1.37 ! cvs 7295: <h3><a name="sectc5221a" id="sectc5221a">The <tt>Indent</tt> rule</a></h3>
1.18 cvs 7296:
1.37 ! cvs 7297: <p>The <tt>Indent</tt> rule is used to modify the value of text indentation
! 7298: in the output files.</p>
1.30 cvs 7299:
1.37 ! cvs 7300: <p>Each time the translator creates a new line in an output file, it
! 7301: generates a variable number of space characters at the beginning of the new
! 7302: line. By default, the number of these characters (the indentation value) is
! 7303: 0. It can be changed with the <tt>Indent</tt> rule.</p>
1.30 cvs 7304:
7305: <p>In its simple form, the rule begins with the <tt>Indent</tt> keyword,
1.25 cvs 7306: followed by the indentation sign (optional) and value and a keyword
1.30 cvs 7307: <tt>Before</tt> or <tt>After</tt> indicating that the indentation should be
7308: changed <a href="#sectc5222">before or after</a> the element's content is
1.37 ! cvs 7309: generated. If the position is not indicated, the indentation is changed
! 7310: before the element's content is generated. This rule, like all translation
1.25 cvs 7311: rules, is terminated by a semicolon.</p>
1.30 cvs 7312:
7313: <p>The indentation value is indicated by an integer, which is the number of
7314: space characters to be generated at the beginning of each new line. A sign
1.18 cvs 7315: (<tt>+</tt> or <tt>-</tt>) can appear before the integer to indicate that the
1.37 ! cvs 7316: value is relative: the current value of indentation is incremented (if sign
! 7317: is <tt>+</tt>) or decremented (if sign is <tt>-</tt>) by the specified
! 7318: value.</p>
1.30 cvs 7319:
7320: <p>Keyword <tt>Suspend</tt> or <tt>Resume</tt> can appear instead of the
1.37 ! cvs 7321: (possibly signed) identation value. <tt>Suspend</tt> means that the new
1.30 cvs 7322: indentation value to be used is zero until another <tt>Indent</tt> rule is
7323: executed and changes the indentation value. <tt>Resume</tt> means that the
7324: indentation value that was used before the last <tt>Indent Suspend</tt> was
1.37 ! cvs 7325: executed becomes the new value. Only one <tt>Suspend</tt> can be used before
1.30 cvs 7326: a <tt>Resume</tt>; <tt>Supend</tt>-<tt>Resume</tt> pairs can not be
7327: nested.</p>
7328:
1.37 ! cvs 7329: <p>Like the <a href="#sectc5210"><tt>Create</tt> rule</a>, the
! 7330: <tt>Indent</tt> keyword can be followed by the <tt>IN</tt> keyword and by the
! 7331: name of a <a href="#sectc526">variable</a>. This means that the rule must not
! 7332: change indentation in the main output file, but in the file whose name is
! 7333: specified by the variable (by default, indentation is changed in the main
! 7334: output file).</p>
1.25 cvs 7335: <pre> 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .
1.10 cvs 7336:
1.25 cvs 7337: Indent = 'Suspend' / 'Resume' / [ IndentSign ] IndentValue .
1.10 cvs 7338: IndentSign = '+' / '-' .
1.18 cvs 7339: IndentValue = NUMBER .</pre>
7340: </div>
1.10 cvs 7341:
1.18 cvs 7342: <div class="subsection">
1.37 ! cvs 7343: <h3><a name="sectc5222" id="sectc5222">Rule application order</a></h3>
1.1 cvs 7344:
1.30 cvs 7345: <p>The translator translates the elements which comprise the document in the
1.37 ! cvs 7346: order induced by the tree structure, except when the <tt>Get</tt> rule is
! 7347: used to change the order of translation. For each element, the translator
! 7348: first applies the rules specified for the element's type that must be applied
! 7349: before translation of the element's content (rules ending with the
! 7350: <tt>Before</tt> keyword or which have no position keyword). If several rules
! 7351: meet these criteria, the translator applies them in the order in where they
! 7352: appear in the translation schema.</p>
! 7353:
! 7354: <p>It then applies all <a href="#sectc5223">rules for the attributes</a>
! 7355: which the element has and which must be applied before the translation of the
! 7356: element's content (rules ending with the <tt>Before</tt> keyword or which
! 7357: have no position keyword). For one attribute value, the translator applies
! 7358: the rules in the order in which they are defined in the translation
! 7359: schema.</p>
1.30 cvs 7360:
7361: <p>The same procedure is followed with translation rules for specific
1.18 cvs 7362: presentations.</p>
1.30 cvs 7363:
1.31 cvs 7364: <p>Next, the element's content is translated, as long as a <tt>Remove</tt> or
7365: <code>Ignore</code> rule does not apply.</p>
1.30 cvs 7366:
7367: <p>In the next step, the translator applies rules for the specific
7368: presentation of the element that are to be applied after translation of the
1.37 ! cvs 7369: content (rules which end with the <tt>After</tt> keyword). The rules for each
1.30 cvs 7370: type of presentation rule or each value are applied in the order in which the
1.18 cvs 7371: translation appear in the schema.</p>
1.30 cvs 7372:
7373: <p>Then, the same procedure is followed for translation rules for attributes
7374: of the element.</p>
7375:
1.37 ! cvs 7376: <p>Finally, the translator applies rules for the element which must be
! 7377: applied after translation of the element's content. These rules are applied
! 7378: in the order that they appear in the translation schema. When the translation
! 7379: of an element is done, the translator procedes to translate the following
1.18 cvs 7380: element.</p>
1.30 cvs 7381:
7382: <p>This order can be changed with the <tt>Attributes</tt> and
1.18 cvs 7383: <tt>Presentation</tt> options of the <a href="#sectc5210"><tt>Create</tt>
7384: rule</a>.</p>
7385: </div>
1.1 cvs 7386:
1.18 cvs 7387: <div class="subsection">
1.37 ! cvs 7388: <h3><a name="sectc5223" id="sectc5223">Translation of logical
! 7389: attributes</a></h3>
1.1 cvs 7390:
1.37 ! cvs 7391: <p>After the rules for the element types, the translation schema defines
! 7392: rules for attribute values. This section begins with the <tt>ATTRIBUTES</tt>
1.1 cvs 7393: keyword and is composed of a sequence of rule blocks each preceded by an
1.18 cvs 7394: attribute name and an optional value or value range.</p>
1.30 cvs 7395:
7396: <p>If the attribute's name appears alone before the rule block, the rule are
1.1 cvs 7397: applied to all element which have the attribute, no matter what value the
1.37 ! cvs 7398: attribute has. In this case, the attribute name is followed by a colon before
1.18 cvs 7399: the beginning of the rule block.</p>
1.30 cvs 7400:
1.37 ! cvs 7401: <p>The attribute's name can be followed by the name of an element type
! 7402: between parentheses. This says, as in presentation schemas, that the rule
! 7403: block which follows applies not to the element which has the attribute, but
! 7404: to its descendants of the type indicated between the parentheses.</p>
1.30 cvs 7405:
7406: <p>If values are given after the attribute name (or after the name of the
1.37 ! cvs 7407: element type), the rules are applied only when the attribute has the
! 7408: indicated values. The same attribute can appear several times, with different
! 7409: values and different translation rules. Attribute values are indicated in the
! 7410: same way as in <a href="#sectc528">conditions</a> and are followed by a colon
! 7411: before the block of rules.</p>
1.30 cvs 7412:
7413: <p>The rule block associated with an attribute is either a simple rule or a
1.18 cvs 7414: sequence of rules delimited by the <tt>BEGIN</tt> and <tt>END</tt> keywords.
7415: Note that rules associated with attribute values cannot be conditional.</p>
1.30 cvs 7416:
7417: <p>Translation rules are not required for all attributes (or their values)
1.37 ! cvs 7418: defined in a structure schema. Only those attributes for which a particular
! 7419: action must be performed by the translator must have such rules. The rules
1.18 cvs 7420: that can be used are those described above, from <a
7421: href="#sectc5210"><tt>Create</tt></a> to <a
7422: href="#sectc5218"><tt>NoTranslation</tt></a>.</p>
1.30 cvs 7423: <pre> AttrSeq = TransAttr < TransAttr > .
1.1 cvs 7424: TransAttr = AttrID [ '(' ElemID ')' ]
7425: [ RelatAttr ] ':' RuleSeq .
7426: AttrID = NAME .
1.18 cvs 7427: ElemID = NAME .</pre>
1.30 cvs 7428:
1.18 cvs 7429: <blockquote class="example">
1.30 cvs 7430: <p><strong>Example:</strong></p>
7431:
7432: <p>The structure defined the ``Language'' attribute which can take the
1.37 ! cvs 7433: values ``French'' and ``English''. To have the French parts of the original
1.30 cvs 7434: document removed and prevent the translation of the leaves of the English
7435: parts, the following rules would be used:</p>
7436: <pre>ATTRIBUTES
1.1 cvs 7437: Language=French :
7438: Remove;
7439: Language=English :
1.18 cvs 7440: NoTranslation;</pre>
7441: </blockquote>
7442: </div>
1.1 cvs 7443:
1.18 cvs 7444: <div class="subsection">
1.37 ! cvs 7445: <h3><a name="sectc5224" id="sectc5224">Translation of specific
! 7446: presentations</a></h3>
1.1 cvs 7447:
1.30 cvs 7448: <p>After the rules for attributes, the translation schema defines rules for
1.37 ! cvs 7449: the specific presentation. This section begins with the <tt>PRESENTATION</tt>
! 7450: keyword and is composed of a sequence of translation rule blocks each
! 7451: preceded by a presentation rule name, optionally accompanied by a part which
! 7452: depends on the particular presentation rule.</p>
1.30 cvs 7453:
7454: <p>Each of these translation rule blocks is applied when the translator
7455: operates on an element which has a specific presentation rule of the type
1.37 ! cvs 7456: indicated at the head of the block. Depending on the type of the specific
1.30 cvs 7457: presentation rule, it is possible to specify values of the presentation rule
7458: for which the translation rule block should be applied.</p>
7459:
7460: <p>There are three categories of the presentation rules:</p>
7461: <ul>
7462: <li>rules taking numeric values: <tt>Size</tt>, <tt>Indent</tt>,
7463: <tt>LineSpacing</tt>, <tt>LineWeight</tt>,</li>
7464: <li>rules whose values are taken from a predefined list (i.e. whose type is
1.36 cvs 7465: an enumeration): <tt>Adjust</tt>, <tt>Hyphenate,/TT>, <tt>Style</tt>,
7466: <tt>Weight</tt>, <tt>Font</tt>, <tt>UnderLine</tt>, <tt>Thickness</tt>,
7467: <tt>LineStyle</tt>,</tt></li>
1.30 cvs 7468: <li>rules whose value is a name: <tt>FillPattern</tt>, <tt>Background</tt>,
7469: <tt>Foreground</tt>.</li>
1.18 cvs 7470: </ul>
1.30 cvs 7471:
7472: <p>For presentation rules of the first category, the values which provoke
1.1 cvs 7473: application of the translation rules are indicated in the same manner as for
1.37 ! cvs 7474: <a href="#relattr">numeric attributes</a>. This can be either a unique value
! 7475: or range of values. For a unique value, the value (an integer) is simply
! 7476: preceded by an equals sign. Value ranges can be specified in one of three
1.18 cvs 7477: ways:</p>
7478: <ul>
1.30 cvs 7479: <li>all values less than a given value (this value is preceded by a ``less
7480: than'' sign '<tt><</tt>'),</li>
7481: <li>all values greater than a given value (this value is preceded by a`
7482: `greater than'' sign '<tt>></tt>'),</li>
1.37 ! cvs 7483: <li>all values falling in an interval, bounds included. The range of values
1.30 cvs 7484: is then specified <tt>IN [</tt>Minimum<tt>..</tt>Maximum<tt>]</tt>, where
7485: Minimum and Maximum are integers.</li>
1.18 cvs 7486: </ul>
1.30 cvs 7487:
7488: <p>All numeric values can be negative, in which case the integer is preceded
1.37 ! cvs 7489: by a minus sign. All values must be given in typographers points.</p>
1.30 cvs 7490:
7491: <p>For presentation rules whose values are taken from a predefined list, the
1.1 cvs 7492: value which provokes application of the translation rules is simply indicated
1.18 cvs 7493: by the equals sign followed by the name of the value.</p>
1.30 cvs 7494:
1.37 ! cvs 7495: <p>For presentation rules whose values are names, the value which provokes
! 7496: the application of translation rules is simply indicated by the equals sign
! 7497: followed by the name of the value. The names of the fill patterns (the
1.18 cvs 7498: <tt>FillPattern</tt> rule) and of the colors (the <tt>Foreground</tt> and
7499: <tt>Background</tt> rules) used in Thot are the same as in the P language.</p>
1.30 cvs 7500: <pre> PresSeq = PresTrans < PresTrans > .
1.1 cvs 7501: PresTrans = PresRule ':' RuleSeq .
7502: PresRule = 'Size' [ PresRelation ] /
7503: 'Indent' [ PresRelation ] /
7504: 'LineSpacing' [ PresRelation ] /
7505: 'Adjust' [ '=' AdjustVal ] /
7506: 'Hyphenate' [ '=' BoolVal ] /
7507: 'Style' [ '=' StyleVal ] /
1.24 cvs 7508: 'Weight' [ '=' WeightVal ] /
1.1 cvs 7509: 'Font' [ '=' FontVal ] /
7510: 'UnderLine' [ '=' UnderLineVal ] /
7511: 'Thickness' [ '=' ThicknessVal ] /
7512: 'LineStyle' [ '=' LineStyleVal ] /
7513: 'LineWeight' [ PresRelation ] /
7514: 'FillPattern' [ '=' Pattern ] /
7515: 'Background' [ '=' Color ] /
7516: 'Foreground' [ '=' Color ] .
7517:
7518: PresRelation = '=' PresValue /
1.30 cvs 7519: '>' [ '-' ] PresMinimum /
1.1 cvs 7520: '<' [ '-' ] PresMaximum /
7521: 'IN' '[' [ '-' ] PresIntervalMin '..'
7522: [ '-' ] PresIntervalMax ']' .
1.35 cvs 7523: AdjustVal = 'Left' / 'Right' / 'VMiddle' / 'Justify' /
1.1 cvs 7524: 'LeftWithDots' .
7525: BoolVal = 'Yes' / 'No' .
1.24 cvs 7526: StyleVal = 'Roman' / 'Italics' / 'Oblique' .
7527: WeightVal = 'Normal' / 'Bold' .
1.1 cvs 7528: FontVal = 'Times' / 'Helvetica' / 'Courier' .
7529: UnderLineVal = 'NoUnderline' / 'UnderLined' /
7530: 'OverLined' / 'CrossedOut' .
7531: ThicknessVal = 'Thick' / 'Thin' .
1.6 cvs 7532: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
1.1 cvs 7533: Pattern = NAME .
7534: Color = NAME .
7535: PresMinimum = NUMBER .
7536: PresMaximum = NUMBER .
7537: PresIntervalMin= NUMBER .
7538: PresIntervalMax= NUMBER .
7539: PresValue = [ '-' ] PresVal .
1.18 cvs 7540: PresVal = NUMBER .</pre>
1.30 cvs 7541:
1.37 ! cvs 7542: <p>The <a name="prestransl" id="prestransl">translation rules associated with
! 7543: specific presentation rules</a> can use the value of the specific
! 7544: presentation rule that causes them to be applied. This behavior is designated
! 7545: by the keyword <tt>Value</tt>. For numerically-valued presentation rules, the
! 7546: numeric value is produced. For other presentation rules, the name of the
! 7547: value is produced.</p>
1.30 cvs 7548:
7549: <p>It should be noted that modifications to the layout of the document's
7550: elements that are made using the combination of the control key and a mouse
7551: button will have no effect on the translation of the document.</p>
7552:
7553: <blockquote class="example">
7554: <p><strong>Example:</strong></p>
7555:
7556: <p>Suppose that it is desirable to use the same font sizes as in the
7557: specific presentation, but the font size must be between 10 and 18
7558: typographer's points. If font size is set in the translated document by the
7559: string <tt>pointsize=n</tt> where <tt>n</tt> is the font size in
7560: typographer's points then the following rules will suffice:</p>
7561: <pre>PRESENTATION
1.1 cvs 7562: Size < 10 :
7563: Create 'pointsize=10';
7564: Size in [10..18] :
7565: BEGIN
7566: Create 'pointsize=';
7567: Create Value;
7568: END;
1.30 cvs 7569: Size > 18 :
1.18 cvs 7570: Create 'pointsize=18';</pre>
7571: </blockquote>
7572: </div>
1.1 cvs 7573:
1.18 cvs 7574: <div class="subsection">
1.37 ! cvs 7575: <h3><a name="sectc5225" id="sectc5225">Recoding of characters, symbols and
! 7576: graphics</a></h3>
1.1 cvs 7577:
1.37 ! cvs 7578: <p>The coding of characters, graphical elements and symbols as defined in
! 7579: Thot does not necessarily correspond to what is required by an application to
! 7580: which a Thot document must be exported. Because of this the translator can
! 7581: recode these terminal elements of the documents structure. The last sections
! 7582: of a translation schema are intended for this purpose, each specifying the
! 7583: recoding rules for one type of terminal element.</p>
1.30 cvs 7584:
1.37 ! cvs 7585: <p>The recoding rules for character strings are grouped by alphabets. There
! 7586: is a group of rules for each alphabet of the Thot document that must be
1.30 cvs 7587: translated. Each such group of rules begins with the <tt>TEXTTRANSLATE</tt>
7588: keyword, followed by the specification of the alphabet to translate and the
7589: recoding rules, between the <tt>BEGIN</tt> and <tt>END</tt> keywords unless
7590: there is only one recoding rule for the alphabet. The specification of the
7591: alphabet is not required: by default it is assumed to the Latin alphabet (the
7592: ISO Latin-1 character set).</p>
7593:
7594: <p>Each recoding rule is formed by a source string between apostrophes and a
1.1 cvs 7595: target string, also between apostrophes, the two strings being separated by
1.30 cvs 7596: the arrow symbol (<tt>-></tt>), formed by the ``minus'' and ``greater
1.37 ! cvs 7597: than'' characters. The rule is terminated by a semi-colon.</p>
1.18 cvs 7598: <pre> TextTransSeq = [ Alphabet ] TransSeq .
1.1 cvs 7599: Alphabet = NAME .
1.30 cvs 7600: TransSeq ='BEGIN' < Translation > 'END' ';' /
1.1 cvs 7601: Translation .
1.30 cvs 7602: Translation = Source [ '->' Target ] ';' .
1.1 cvs 7603: Source = STRING .
1.18 cvs 7604: Target = STRING .</pre>
1.30 cvs 7605:
7606: <p>One such rule signifies that when the source string appears in a text leaf
7607: of the document being translated, the translator must replace it, in the
1.37 ! cvs 7608: translated document, with the target string. The source string and the target
! 7609: string can have different lengths and the target string can be empty. In this
1.1 cvs 7610: last case, the translator simply suppresses every occurrence of the source
1.18 cvs 7611: string in the translated document.</p>
1.30 cvs 7612:
7613: <p>For a given alphabet, the order of the rules is not important and has no
1.1 cvs 7614: significance because the T language compiler reorders the rules in ways that
1.37 ! cvs 7615: speed up the translator's work. The total number of recoding rules is limited
1.18 cvs 7616: by the compiler as is the maximum length of the source and target strings.</p>
1.30 cvs 7617:
7618: <p>The recoding rules for symbols and graphical elements are written in the
1.37 ! cvs 7619: same manner as the recoding rules for character strings. They are preceded,
! 7620: respectively, by the <tt>SYMBTRANSLATE</tt> and <tt>GRAPHTRANSLATE</tt> and
! 7621: so not require a specification of the alphabet. Their source string is
! 7622: limited to one character, since, in Thot, each symbol and each graphical
! 7623: element is represented by a single character. The symbol and graphical
! 7624: element codes are defined along with the <a href="#sect7">non-standard
! 7625: character codes</a>.</p>
1.30 cvs 7626:
1.18 cvs 7627: <blockquote class="example">
1.30 cvs 7628: <p><strong>Example:</strong></p>
7629:
7630: <p>In a translation schema producing documents destined for use with the
7631: L<sup>A</sup>T<sub><big>E</big></sub>X formatter, the Latin characters``é''
1.37 ! cvs 7632: (octal code 351 in Thot) and ``č'' (octal code 350 in Thot) must be
1.30 cvs 7633: converted to their representation in
7634: L<sup>A</sup>T<sub><big>E</big></sub>X:</p>
7635: <pre>TEXTTRANSLATE Latin
1.1 cvs 7636: BEGIN
1.30 cvs 7637: '\350' -> '\`{e}'; { e grave }
7638: '\351' -> '\''{e}'; { e acute }
1.18 cvs 7639: END;</pre>
7640: </blockquote>
7641: </div>
7642: </div>
1.37 ! cvs 7643: <hr />
1.18 cvs 7644: </div>
1.1 cvs 7645:
1.18 cvs 7646: <div class="chapter">
1.37 ! cvs 7647: <h1><a name="sect6" id="sect6">Language grammars</a></h1>
1.1 cvs 7648:
1.30 cvs 7649: <p>This chapter gives the complete grammars of the languages of Thot. The
1.1 cvs 7650: grammars were presented and described in the preceding chapters, which also
1.37 ! cvs 7651: specify the semantics of the languages. This section gives only the
1.18 cvs 7652: syntax.</p>
1.1 cvs 7653:
1.18 cvs 7654: <div class="section">
1.37 ! cvs 7655: <h2><a name="sectb61" id="sectb61">The M meta-language</a></h2>
1.1 cvs 7656:
1.30 cvs 7657: <p>The language grammars are all expressed in the same formalism, the M
1.18 cvs 7658: meta-language, which is defined in this section.</p>
7659: <pre>{ Any text between braces is a comment. }
1.30 cvs 7660: Grammar = Rule < Rule > 'END' .
7661: { The < and > signs indicate zero }
1.1 cvs 7662: { or more repetitions. }
7663: { END marks the end of the grammar. }
7664: Rule = Ident '=' RightPart '.' .
7665: { The period indicates the end of a rule }
7666: RightPart = RtTerminal / RtIntermed .
7667: { The slash indicates a choice }
7668: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
7669: { Right part of a terminal rule }
1.30 cvs 7670: RtIntermed = Possibility < '/' Possibility > .
1.1 cvs 7671: { Right part of an intermediate rule }
1.30 cvs 7672: Possibility = ElemOpt < ElemOpt > .
7673: ElemOpt = Element / '[' Element < Element > ']' /
7674: '<' Element < Element > '>' .
1.1 cvs 7675: { Brackets delimit optional parts }
7676: Element = Ident / KeyWord .
7677: Ident = NAME .
7678: { Identifier, sequence of characters
7679: KeyWord = STRING .
7680: { Character string delimited by apostrophes }
1.18 cvs 7681: END</pre>
7682: </div>
1.1 cvs 7683:
1.18 cvs 7684: <div class="section">
1.37 ! cvs 7685: <h2><a name="sectb62" id="sectb62">The S language</a></h2>
1.1 cvs 7686:
1.30 cvs 7687: <p>The S language is used to write structure schemas, which contain the
1.37 ! cvs 7688: generic logical structures of document and object classes. It is described
1.30 cvs 7689: here in the M meta-language.</p>
1.18 cvs 7690: <pre>StructSchema = 'STRUCTURE' [ 'EXTENSION' ] ElemID ';'
1.1 cvs 7691: 'DEFPRES' PresID ';'
7692: [ 'ATTR' AttrSeq ]
7693: [ 'STRUCT' RulesSeq ]
7694: [ 'EXTENS' ExtensRuleSeq ]
7695: [ 'UNITS' RulesSeq ]
7696: [ 'EXPORT' SkeletonSeq ]
7697: [ 'EXCEPT' ExceptSeq ]
7698: 'END' .
7699:
7700: ElemID = NAME .
7701: PresID = NAME .
7702:
1.30 cvs 7703: AttrSeq = Attribute < Attribute > .
1.1 cvs 7704: Attribute = AttrID '=' AttrType ';' .
7705: AttrType = 'INTEGER' / 'TEXT' /
7706: 'REFERENCE' '(' RefType ')' /
7707: ValueSeq .
7708: RefType = 'ANY' /
7709: [ FirstSec ] ElemID [ ExtStruct ] .
1.30 cvs 7710: ValueSeq = AttrVal < ',' AttrVal > .
1.1 cvs 7711: AttrID = NAME .
7712: FirstSec = 'First' / 'Second' .
7713: ExtStruct = '(' ElemID ')' .
7714: AttrVal = NAME .
7715:
1.30 cvs 7716: RulesSeq = Rule < Rule > .
1.1 cvs 7717: Rule = ElemID [ LocAttrSeq ] '='
7718: DefWithAttr ';' .
7719: LocAttrSeq = '(' 'ATTR' LocalAttr
1.30 cvs 7720: < ';' LocalAttr > ')' .
1.1 cvs 7721: LocalAttr = [ '!' ] AttrID [ '=' AttrType ] .
7722: DefWithAttr = Definition
7723: [ '+' '(' ExtensionSeq ')' ]
7724: [ '-' '(' RestrictSeq ')' ]
7725: [ 'WITH' FixedAttrSeq ] .
1.30 cvs 7726: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1.1 cvs 7727: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
7728: 'SYMBOL' / 'PICTURE' .
1.30 cvs 7729: RestrictSeq = RestrictElem < ',' RestrictElem > .
1.1 cvs 7730: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
7731: 'SYMBOL' / 'PICTURE' .
1.30 cvs 7732: FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 7733: FixedAttr = AttrID [ FixedOrModifVal ] .
7734: FixedOrModifVal= [ '?' ] '=' FixedValue .
7735: FixedValue = [ '-' ] NumValue / TextValue / AttrVal .
7736: NumValue = NUMBER .
7737: TextValue = STRING .
7738:
7739: Definition = BaseType [ LocAttrSeq ] / Constr /
7740: Element .
7741: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' /
7742: 'PICTURE' / 'UNIT' / 'NATURE' .
7743: Element = ElemID [ ExtOrDef ] .
7744: ExtOrDef = 'EXTERN' / 'INCLUDED' /
7745: [ LocAttrSeq ] '=' Definition .
7746:
7747: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
7748: '(' DefWithAttr ')' /
7749: 'BEGIN' DefOptSeq 'END' /
7750: 'AGGREGATE' DefOptSeq 'END' /
7751: 'CASE' 'OF' DefSeq 'END' /
7752: 'REFERENCE' '(' RefType ')' /
7753: 'PAIR' .
7754:
7755: min = Integer / '*' .
7756: max = Integer / '*' .
7757: Integer = NUMBER .
7758:
1.30 cvs 7759: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.1 cvs 7760: DefOpt = [ '?' ] DefWithAttr .
7761:
1.30 cvs 7762: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .
1.1 cvs 7763:
1.30 cvs 7764: SkeletonSeq = SkeletonElem < ',' SkeletonElem > ';' .
1.1 cvs 7765: SkeletonElem = ElemID [ 'WITH' Contents ] .
7766: Contents = 'Nothing' / ElemID [ ExtStruct ] .
7767:
1.30 cvs 7768: ExceptSeq = Except ';' < Except ';' > .
1.1 cvs 7769: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr ':'
7770: ExcValSeq .
7771: ExcTypeOrAttr = ElemID / AttrID .
1.30 cvs 7772: ExcValSeq = ExcValue < ',' ExcValue > .
1.1 cvs 7773: ExcValue = 'NoCut' / 'NoCreate' /
7774: 'NoHMove' / 'NoVMove' / 'NoMove' /
7775: 'NoHResize' / 'NoVResize' / 'NoResize' /
1.18 cvs 7776: 'MoveResize' /
1.1 cvs 7777: 'NewWidth' / 'NewHeight' /
7778: 'NewHPos' / 'NewVPos' /
7779: 'Invisible' / 'NoSelect' /
7780: 'Hidden' / 'ActiveRef' /
7781: 'ImportLine' / 'ImportParagraph' /
1.9 cvs 7782: 'NoPaginate' / 'ParagraphBreak' /
7783: 'HighlightChildren' / 'ExtendedSelection' /
1.36 cvs 7784: 'SelectParent' / 'ClickableSurface' /
1.29 cvs 7785: 'ReturnCreateNL' / 'ReturnCreateWithin' .
1.1 cvs 7786:
1.30 cvs 7787: ExtensRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.1 cvs 7788: ExtensRule = RootOrElem [ LocAttrSeq ]
7789: [ '+' '(' ExtensionSeq ')' ]
7790: [ '-' '(' RestrictSeq ')' ]
7791: [ 'WITH' FixedAttrSeq ] .
7792: RootOrElem = 'Root' / ElemID .
7793:
1.18 cvs 7794: END</pre>
7795: </div>
1.1 cvs 7796:
1.18 cvs 7797: <div class="section">
1.37 ! cvs 7798: <h2><a name="sectb63" id="sectb63">The P language</a></h2>
1.1 cvs 7799:
1.30 cvs 7800: <p>The P language is used to write presentation schemas, which define the
1.1 cvs 7801: graphical presentation rules to be applied to different classes of documents
1.37 ! cvs 7802: and objects. It is described here in the M meta-language.</p>
1.18 cvs 7803: <pre>PresSchema = 'PRESENTATION' ElemID ';'
1.1 cvs 7804: [ 'VIEWS' ViewSeq ]
7805: [ 'PRINT' PrintViewSeq ]
7806: [ 'COUNTERS' CounterSeq ]
7807: [ 'CONST' ConstSeq ]
7808: [ 'VAR' VarSeq ]
7809: [ 'DEFAULT' ViewRuleSeq ]
7810: [ 'BOXES' BoxSeq ]
7811: [ 'RULES' PresentSeq ]
7812: [ 'ATTRIBUTES' PresAttrSeq ]
7813: [ 'TRANSMIT' TransmitSeq ]
7814: 'END' .
7815:
7816: ElemID = NAME .
7817:
7818: ViewSeq = ViewDeclaration
1.30 cvs 7819: < ',' ViewDeclaration > ';' .
1.1 cvs 7820: ViewDeclaration = ViewID [ 'EXPORT' ] .
7821: ViewID = NAME .
7822:
1.30 cvs 7823: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.37 ! cvs 7824: PrintView = ViewID .
1.1 cvs 7825:
1.30 cvs 7826: CounterSeq = Counter < Counter > .
1.1 cvs 7827: Counter = CounterID ':' CounterFunc ';' .
7828: CounterID = NAME .
7829: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
7830: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.30 cvs 7831: SetFunction < SetFunction >
7832: AddFunction < AddFunction >
1.1 cvs 7833: [ 'INIT' AttrID ] /
1.16 cvs 7834: 'RLEVEL' 'OF' ElemID .
1.1 cvs 7835: SLevelAsc = [ '-' ] LevelAsc .
7836: LevelAsc = NUMBER .
7837: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
7838: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
7839: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 7840: [ '*' ] ElemID .
1.1 cvs 7841: CounterValue = NUMBER .
7842:
1.30 cvs 7843: ConstSeq = Const < Const > .
1.1 cvs 7844: Const = ConstID '=' ConstType ConstValue ';' .
7845: ConstID = NAME .
7846: ConstType = 'Text' [ Alphabet ] / 'Symbol' /
7847: 'Graphics' / 'Picture' .
7848: ConstValue = STRING .
7849: Alphabet = NAME .
7850:
1.30 cvs 7851: VarSeq = Variable < Variable > .
1.1 cvs 7852: Variable = VarID ':' FunctionSeq ';' .
7853: VarID = NAME .
1.30 cvs 7854: FunctionSeq = Function < Function > .
1.1 cvs 7855: Function = 'DATE' / 'FDATE' /
7856: 'DocName' / 'DirName' /
7857: 'ElemName' / 'AttributeName' /
7858: ConstID / ConstType ConstValue /
7859: AttrID /
7860: 'VALUE' '(' PageAttrCtr ','
7861: CounterStyle ')' .
7862: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
7863: [ MinMax ] CounterID / AttrID .
7864: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
7865: 'Uppercase' / 'Lowercase' .
7866: MinMax = 'MaxRangeVal' / 'MinRangeVal' .
7867:
1.30 cvs 7868: BoxSeq = Box < Box > .
1.1 cvs 7869: Box = 'FORWARD' BoxID ';' /
7870: BoxID ':' ViewRuleSeq .
7871: BoxID = NAME .
7872:
1.30 cvs 7873: PresentSeq = Present < Present > .
1.1 cvs 7874: Present = [ '*' ] [ FirstSec ] ElemID ':'
7875: ViewRuleSeq .
7876: FirstSec = 'First' / 'Second' .
7877:
1.30 cvs 7878: PresAttrSeq = PresAttr < PresAttr > .
1.1 cvs 7879: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
7880: [ AttrRelation ] ':' ViewRuleSeq .
7881: AttrID = NAME .
7882: AttrRelation = '=' AttrVal /
1.30 cvs 7883: '>' [ '-' ] MinValue /
1.1 cvs 7884: '<' [ '-' ] MaxValue /
7885: 'IN' '[' [ '-' ] LowerBound '..'
7886: [ '-' ] UpperBound ']' /
7887: 'GREATER' AttrID /
7888: 'EQUAL' AttrID /
7889: 'LESS' AttrID .
7890: AttrVal = [ '-' ] EqualNum / EqualText / AttrValue .
7891: MinValue = NUMBER .
7892: MaxValue = NUMBER .
7893: LowerBound = NUMBER .
7894: UpperBound = NUMBER.
7895: EqualNum = NUMBER .
7896: EqualText = STRING .
7897: AttrValue = NAME .
7898:
1.30 cvs 7899: ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 7900: 'END' ';' /
7901: ViewRules / CondRules / Rule .
7902: RulesAndCond = CondRules / Rule .
7903: ViewRules = 'IN' ViewID CondRuleSeq .
1.30 cvs 7904: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
1.1 cvs 7905: CondRules / Rule .
1.30 cvs 7906: CondRules = CondRule < CondRule >
1.1 cvs 7907: [ 'Otherwise' RuleSeq ] .
7908: CondRule = 'IF' ConditionSeq RuleSeq .
1.30 cvs 7909: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' / Rule .
1.1 cvs 7910:
1.30 cvs 7911: ConditionSeq = Condition < 'AND' Condition > .
1.6 cvs 7912: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
7913: ConditionElem = 'First' / 'Last' /
7914: [ 'Immediately' ] 'Within' [ NumParent ]
7915: ElemID [ ExtStruct ] /
7916: ElemID /
7917: 'Referred' / 'FirstRef' / 'LastRef' /
7918: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
7919: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
7920: 'UserPage' / 'StartPage' / 'ComputedPage' /
1.33 cvs 7921: 'Empty' / 'Root' /
1.6 cvs 7922: '(' [ MinMax ] CounterName CounterCond ')' /
7923: CondPage '(' CounterID ')' .
7924: NumParent = [ GreaterLess ] NParent .
1.30 cvs 7925: GreaterLess = '>' / '<' .
1.6 cvs 7926: NParent = NUMBER.
1.30 cvs 7927: CounterCond = '<' MaxCtrVal / '>' MinCtrVal /
1.6 cvs 7928: '=' EqCtrVal /
7929: 'IN' '[' ['-'] MinCtrBound '..'
7930: ['-'] MaxCtrBound ']' .
7931: PageCond = 'Even' / 'Odd' / 'One' .
7932: MaxCtrVal = NUMBER .
7933: MinCtrVal = NUMBER .
7934: EqCtrVal = NUMBER .
7935: MaxCtrBound = NUMBER .
7936: MinCtrBound = NUMBER .
1.1 cvs 7937:
1.34 cvs 7938: Rule = Property ';' / PresFunc ';' .
7939: Property = 'VertRef' ':' HorizPosition /
1.1 cvs 7940: 'HorizRef' ':' VertPosition /
7941: 'VertPos' ':' VPos /
7942: 'HorizPos' ':' HPos /
7943: 'Height' ':' Extent /
7944: 'Width' ':' Extent /
7945: 'VertOverflow' ':' Boolean /
7946: 'HorizOverflow' ':' Boolean /
1.26 cvs 7947: 'MarginTop' ':' MarginWidth /
7948: 'MarginRight' ':' MarginWidth /
7949: 'MarginBottom' ':' MarginWidth /
7950: 'MarginLeft' ':' MarginWidth /
7951: 'PaddingTop' ':' PaddingWidth /
7952: 'PaddingRight' ':' PaddingWidth /
7953: 'PaddingBottom' ':' PaddingWidth /
7954: 'PaddingLeft' ':' PaddingWidth /
7955: 'BorderTopWidth' ':' BorderWidth /
7956: 'BorderRightWidth' ':' BorderWidth /
7957: 'BorderBottomWidth' ':' BorderWidth /
7958: 'BorderLeftWidth' ':' BorderWidth /
7959: 'BorderTopColor' ':' BorderColor /
7960: 'BorderRightColor' ':' BorderColor /
7961: 'BorderBottomColor' ':' BorderColor /
7962: 'BorderLeftColor' ':' BorderColor /
7963: 'BorderTopStyle' ':' BorderStyle /
7964: 'BorderRightStyle' ':' BorderStyle /
7965: 'BorderBottomStyle' ':' BorderStyle /
7966: 'BorderLeftStyle' ':' BorderStyle .
1.1 cvs 7967: 'LineSpacing' ':' DistOrInherit /
7968: 'Indent' ':' DistOrInherit /
7969: 'Adjust' ':' AlignOrInherit /
7970: 'Hyphenate' ':' BoolInherit /
7971: 'PageBreak' ':' Boolean /
7972: 'LineBreak' ':' Boolean /
7973: 'InLine' ':' Boolean /
7974: 'NoBreak1' ':' AbsDist /
7975: 'NoBreak2' ':' AbsDist /
7976: 'Gather' ':' Boolean /
7977: 'Visibility' ':' NumberInherit /
7978: 'Size' ':' SizeInherit /
7979: 'Font' ':' NameInherit /
7980: 'Style' ':' StyleInherit /
1.23 cvs 7981: 'Weight' ':' WeightInherit /
1.1 cvs 7982: 'Underline' ':' UnderLineInherit /
7983: 'Thickness' ':' ThicknessInherit /
7984: 'Depth' ':' NumberInherit /
7985: 'LineStyle' ':' LineStyleInherit /
7986: 'LineWeight' ':' DistOrInherit /
7987: 'FillPattern' ':' NameInherit /
1.30 cvs 7988: 'Background' ':' Color /
7989: 'Foreground' ':' Color /
1.1 cvs 7990: 'Content' ':' VarConst .
7991: PresFunc = Creation '(' BoxID ')' /
7992: 'Line' /
7993: 'NoLine' /
7994: 'Page' '(' BoxID ')' /
1.13 cvs 7995: 'Copy' '(' BoxTypeToCopy ')' /
7996: 'ShowBox' /
1.18 cvs 7997: 'BackgroundPicture' ':' FileName /
7998: 'PictureMode' ':' PictMode .
1.1 cvs 7999:
8000: BoxTypeToCopy = BoxID [ ExtStruct ] /
8001: ElemID [ ExtStruct ] .
8002: ExtStruct = '(' ElemID ')' .
8003:
8004: Distance = [ Sign ] AbsDist .
8005: Sign = '+' / '-' .
8006: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
8007: [ Unit ] .
8008: IntegerOrAttr = IntegerPart / AttrID .
8009: IntegerPart = NUMBER .
8010: DecimalPart = NUMBER .
8011: Unit = 'em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
8012: 'pc' / 'px' / '%' .
8013:
8014: HPos = 'nil' / VertAxis '=' HorizPosition
8015: [ 'UserSpecified' ] .
8016: VPos = 'nil' / HorizAxis '=' VertPosition
8017: [ 'UserSpecified' ] .
8018: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
8019: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .
8020:
1.6 cvs 8021: VertPosition = Reference '.' HorizAxis [ Distance ] .
8022: HorizPosition = Reference '.' VertAxis [ Distance ] .
8023: Reference = 'Enclosing' [ BoxTypeNot ] /
8024: 'Enclosed' [ BoxTypeNot ] /
8025: 'Previous' [ BoxTypeNot ] /
8026: 'Next' [ BoxTypeNot ] /
8027: 'Referred' [ BoxTypeNot ] /
8028: 'Creator' /
8029: 'Root' /
8030: '*' /
8031: BoxOrType .
8032: BoxOrType = BoxID /
8033: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 8034: 'AnyElem' / 'AnyBox' /
8035: 'ElemWithAttr' AttrID .
1.6 cvs 8036: BoxTypeNot = [ 'NOT' ] BoxOrType .
8037:
8038: Extent = Reference '.' HeightWidth
8039: [ Relation ] [ 'Min' ] /
8040: AbsDist [ 'UserSpecified' ] [ 'Min' ] /
8041: HPos / VPos .
8042: HeightWidth = 'Height' / 'Width' .
8043: Relation = '*' ExtentAttr '%' / Distance .
8044: ExtentAttr = ExtentVal / AttrID .
8045: ExtentVal = NUMBER .
1.26 cvs 8046:
8047: MarginWidth = InheritParent / 'Auto' / Distance .
8048: PaddingWidth = InheritParent / Distance .
8049: BorderWidth = InheritParent / 'Thin' / 'Medium' / 'Thick' / Distance .
8050: BorderColor = InheritParent / 'Transparent' / 'Foreground' /
8051: ColorName .
8052: BorderStyle = InheritParent /
8053: 'None' / 'Hidden' / 'Dotted' / 'Dashed' / 'Solid' /
8054: 'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
1.27 cvs 8055: InheritParent = 'Enclosing' '=' / 'Creator' '=' .
1.26 cvs 8056: ColorName = NAME .
1.6 cvs 8057:
8058: Inheritance = Kinship InheritedValue .
8059: Kinship = 'Enclosing' / 'GrandFather'/ 'Enclosed' /
8060: 'Previous' / 'Creator' .
8061: InheritedValue = '+' PosIntAttr [ 'Max' maximumA ] /
8062: '-' NegIntAttr [ 'Min' minimumA ] /
8063: '=' .
8064: PosIntAttr = PosInt / AttrID .
8065: PosInt = NUMBER .
8066: NegIntAttr = NegInt / AttrID .
8067: NegInt = NUMBER .
8068: maximumA = maximum / AttrID .
8069: maximum = NUMBER .
8070: minimumA = minimum / AttrID .
8071: minimum = NUMBER .
8072:
8073: AlignOrInherit = Kinship '=' / Alignment .
8074: Alignment = 'Left' / 'Right' / 'VMiddle' /
8075: 'LeftWithDots' .
1.1 cvs 8076:
1.6 cvs 8077: DistOrInherit = Kinship InheritedDist / Distance .
8078: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .
1.1 cvs 8079:
1.6 cvs 8080: BoolInherit = Boolean / Kinship '=' .
8081: Boolean = 'Yes' / 'No' .
1.1 cvs 8082:
1.6 cvs 8083: NumberInherit = Integer / AttrID / Inheritance .
8084: Integer = NUMBER .
1.1 cvs 8085:
8086: LineStyleInherit= Kinship '=' / 'Solid' / 'Dashed' /
8087: 'Dotted' .
8088:
1.6 cvs 8089: SizeInherit = SizeAttr [ 'pt' ] / Kinship InheritedSize .
8090: InheritedSize = '+' SizeAttr [ 'pt' ]
8091: [ 'Max' MaxSizeAttr ] /
8092: '-' SizeAttr [ 'pt' ]
8093: [ 'Min' MinSizeAttr ] /
1.22 cvs 8094: '*' PercentSizeAttr '%' /
1.6 cvs 8095: '=' .
8096: SizeAttr = Size / AttrID .
8097: Size = NUMBER .
8098: MaxSizeAttr = MaxSize / AttrID .
8099: MaxSize = NUMBER .
8100: MinSizeAttr = MinSize / AttrID .
8101: MinSize = NUMBER .
1.22 cvs 8102: PercentSizeAttr = PercentSize / AttrID .
8103: PercentSize = NUMBER .
1.6 cvs 8104:
8105: NameInherit = Kinship '=' / FontName .
8106: FontName = NAME .
1.30 cvs 8107: Color = 'Transparent' / Kinship '=' / FontName .
1.6 cvs 8108: StyleInherit = Kinship '=' /
1.23 cvs 8109: 'Roman' / 'Italics' / 'Oblique' .
8110: WeightInherit = Kinship '=' /
8111: 'Normal' / 'Bold' .
1.1 cvs 8112: UnderLineInherit= Kinship '=' /
1.6 cvs 8113: 'NoUnderline' / 'Underlined' /
8114: 'Overlined' / 'CrossedOut' .
1.1 cvs 8115: ThicknessInherit= Kinship '=' / 'Thick' / 'Thin' .
1.13 cvs 8116:
8117: FileName = STRING .
8118: PictMode = 'NormalSize' / 'Scale' /
8119: 'RepeatXY' / 'RepeatX' / 'RepeatY' .
1.1 cvs 8120:
1.6 cvs 8121: VarConst = ConstID / ConstType ConstValue /
8122: VarID / '(' FunctionSeq ')' /
8123: ElemID .
8124:
8125: Creation = Create [ 'Repeated' ] .
8126: Create = 'CreateFirst' / 'CreateLast' /
8127: 'CreateBefore' / 'CreateAfter' /
8128: 'CreateEnclosing' .
8129:
1.30 cvs 8130: TransmitSeq = Transmit < Transmit > .
1.6 cvs 8131: Transmit = TypeOrCounter 'To' ExternAttr
8132: '(' ElemID ')' ';' .
8133: TypeOrCounter = CounterID / ElemID .
8134: ExternAttr = NAME .
1.1 cvs 8135:
1.18 cvs 8136: END</pre>
8137: </div>
1.1 cvs 8138:
1.18 cvs 8139: <div class="section">
1.37 ! cvs 8140: <h2><a name="sectb64" id="sectb64">The T language</a></h2>
1.18 cvs 8141: <pre>TransSchema = 'TRANSLATION' ElemID ';'
1.1 cvs 8142: [ 'LINELENGTH' LineLength ';' ]
8143: [ 'LINEEND' CHARACTER ';' ]
8144: [ 'LINEENDINSERT' STRING ';' ]
8145: [ 'BUFFERS' BufferSeq ]
8146: [ 'COUNTERS' CounterSeq ]
8147: [ 'CONST' ConstSeq ]
8148: [ 'VAR' VariableSeq ]
8149: 'RULES' ElemSeq
8150: [ 'ATTRIBUTES' AttrSeq ]
8151: [ 'PRESENTATION' PresSeq ]
1.30 cvs 8152: < 'TEXTTRANSLATE' TextTransSeq >
1.1 cvs 8153: [ 'SYMBTRANSLATE' TransSeq ]
8154: [ 'GRAPHTRANSLATE' TransSeq ]
8155: 'END' .
8156:
8157: LineLength = NUMBER .
8158:
1.30 cvs 8159: BufferSeq = Buffer < Buffer > .
1.1 cvs 8160: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
8161: BufferID = NAME .
8162:
1.30 cvs 8163: CounterSeq = Counter < Counter > .
1.1 cvs 8164: Counter = CounterID [ ':' CounterFunc ] ';' .
8165: CounterID = NAME .
8166: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
8167: [ 'Init' AttrID ] /
8168: 'Rlevel' 'of' ElemID /
8169: 'Set' InitValue 'On' ElemID
8170: 'Add' Increment 'On' ElemID
8171: [ 'Init' AttrID ] .
8172: SLevelAsc = [ '-' ] LevelAsc .
8173: LevelAsc = NUMBER .
8174: InitValue = NUMBER .
8175: Increment = NUMBER .
8176: ElemID = NAME .
8177: AttrID = NAME .
8178:
1.30 cvs 8179: ConstSeq = Const < Const > .
1.1 cvs 8180: Const = ConstID '=' ConstValue ';' .
8181: ConstID = NAME .
8182: ConstValue = STRING .
8183:
1.30 cvs 8184: VariableSeq = Variable < Variable > .
8185: Variable = VarID ':' Function < Function > ';' .
1.1 cvs 8186: VarID = NAME .
8187: Function = 'Value' '(' CounterID [ ':' Length ]
8188: [ ',' CounterStyle ] ')' /
8189: 'FileDir' / 'FileName' / 'Extension' /
8190: 'DocumentName' / 'DocumentDir' /
8191: ConstID / CharString /
8192: BufferID / AttrID .
8193: Length = NUMBER .
8194: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
8195: 'Uppercase' / 'Lowercase' .
8196: CharString = STRING .
8197:
1.30 cvs 8198: ElemSeq = TransType < TransType > .
1.1 cvs 8199: TransType = [ FirstSec ] ElemID ':' RuleSeq .
8200: FirstSec = 'First' / 'Second' .
1.30 cvs 8201: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
1.1 cvs 8202: Rule = SimpleRule / ConditionBlock .
8203: ConditionBlock= 'IF' ConditionSeq SimpleRuleSeq .
1.30 cvs 8204: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.1 cvs 8205: SimpleRule .
8206:
8207: ConditionSeq = Condition [ 'AND' Condition ] .
8208: Condition = [ 'NOT' ] [ 'Target' ] Cond .
8209: Cond = CondElem / CondAscend .
8210: CondElem = 'FirstRef' / 'LastRef' /
8211: 'ExternalRef' /
8212: 'Alphabet' '=' Alphabet /
8213: 'ComputedPage' / 'StartPage' /
8214: 'UserPage' / 'ReminderPage' /
8215: 'Empty' /
1.18 cvs 8216: ElemID /
1.1 cvs 8217: 'FirstAttr' / 'LastAttr' .
8218: CondAscend = [ Ascend ] CondOnAscend .
8219: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
8220: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
8221: CondRelLevel = NUMBER .
8222: CondOnAscend = 'First' / 'Last' /
8223: 'Referred' /
8224: [ 'Immediately' ] 'Within' [ NumParent ]
8225: ElemID [ ExtStruct ] /
8226: 'Attributes' /
8227: AttrID [ RelatAttr ] /
8228: 'Presentation' /
1.34 cvs 8229: PresRule .
1.1 cvs 8230: NumParent = [ GreaterLess ] NParent .
1.30 cvs 8231: GreaterLess = '>' / '<' .
1.1 cvs 8232: NParent = NUMBER.
8233: Alphabet = NAME .
8234: RelatAttr = '=' Value /
1.30 cvs 8235: '>' [ '-' ] Minimum /
1.1 cvs 8236: '<' [ '-' ] Maximum /
8237: 'IN' '[' [ '-' ] MinInterval '..'
8238: [ '-' ] MaxInterval ']' .
8239: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
8240: Minimum = NUMBER .
8241: Maximum = NUMBER .
8242: MinInterval = NUMBER .
8243: MaxInterval = NUMBER .
8244: IntegerVal = NUMBER .
8245: TextVal = STRING .
8246: AttrValue = NAME .
8247:
8248: SimpleRule = 'Create' [ 'IN' VarID ] Object
8249: [ Position ] ';' /
8250: 'Write' Object [ Position ] ';' /
8251: 'Read' BufferID [ Position ] ';' /
8252: 'Include' File [ Position ] ';' /
1.6 cvs 8253: 'Get' [ RelPosition ] ElemID
8254: [ ExtStruct ]
8255: [ Position ] ';' /
1.1 cvs 8256: 'Copy' [ RelPosition ] ElemID
8257: [ ExtStruct ]
8258: [ Position ] ';' /
8259: 'Use' TrSchema [ 'For' ElemID ] ';' /
8260: 'Remove' ';' /
1.31 cvs 8261: 'Ignore' ';' /
1.1 cvs 8262: 'NoTranslation' ';' /
8263: 'NoLineBreak' ';' /
8264: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 8265: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 8266: 'Set' CounterID InitValue [ Position ] ';' /
8267: 'Add' CounterID Increment [ Position ] ';' /
1.25 cvs 8268: 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .
1.10 cvs 8269:
1.25 cvs 8270: Indent = 'Suspend' / 'Resume' / [ IndentSign ] IndentValue .
1.10 cvs 8271: IndentSign = '+' / '-' .
8272: IndentValue = NUMBER .
1.1 cvs 8273:
8274: Object = ConstID / CharString /
8275: BufferID /
8276: VarID /
1.30 cvs 8277: '(' Function < Function > ')' /
1.21 cvs 8278: [ 'Translated' ] AttrID /
1.1 cvs 8279: 'Value' /
8280: 'Content' /
8281: 'Attributes' /
8282: 'Presentation' /
8283: 'RefId' /
8284: 'PairId' /
8285: 'FileDir' / 'FileName' / 'Extension' /
8286: 'DocumentName' / 'DocumentDir' /
8287: [ 'Referred' ] ReferredObject .
8288: Position = 'After' / 'Before' .
8289:
1.6 cvs 8290: ReferredObject= VarID /
8291: ElemID [ ExtStruct ] /
8292: 'RefId' /
8293: 'DocumentName' / 'DocumentDir' .
1.1 cvs 8294:
1.6 cvs 8295: File = FileName / BufferID .
8296: FileName = STRING .
1.1 cvs 8297:
1.6 cvs 8298: RelPosition = 'Included' / 'Referred' .
8299: ExtStruct = '(' ElemID ')' .
1.1 cvs 8300:
1.6 cvs 8301: TrSchema = NAME .
8302:
1.30 cvs 8303: AttrSeq = TransAttr < TransAttr > .
1.6 cvs 8304: TransAttr = AttrID [ '(' ElemID ')' ]
8305: [ RelatAttr ] ':' RuleSeq .
8306:
1.30 cvs 8307: PresSeq = PresTrans < PresTrans > .
1.6 cvs 8308: PresTrans = PresRule ':' RuleSeq .
8309: PresRule = 'Size' [ PresRelation ] /
8310: 'Indent' [ PresRelation ] /
8311: 'LineSpacing' [ PresRelation ] /
8312: 'Adjust' [ '=' AdjustVal ] /
8313: 'Hyphenate' [ '=' BoolVal ] /
8314: 'Style' [ '=' StyleVal ] /
1.24 cvs 8315: 'Weight' [ '=' WeightVal ] /
1.6 cvs 8316: 'Font' [ '=' FontVal ] /
8317: 'UnderLine' [ '=' UnderLineVal ] /
8318: 'Thickness' [ '=' ThicknessVal ] /
8319: 'LineStyle' [ '=' LineStyleVal ] /
8320: 'LineWeight' [ PresRelation ] /
8321: 'FillPattern' [ '=' Pattern ] /
8322: 'Background' [ '=' Color ] /
8323: 'Foreground' [ '=' Color ] .
8324:
8325: PresRelation = '=' PresValue /
1.30 cvs 8326: '>' [ '-' ] PresMinimum /
1.6 cvs 8327: '<' [ '-' ] PresMaximum /
8328: 'IN' '[' [ '-' ] PresIntervalMin '..'
8329: [ '-' ] PresIntervalMax ']' .
1.35 cvs 8330: AdjustVal = 'Left' / 'Right' / 'VMiddle' / 'Justify' /
1.6 cvs 8331: 'LeftWithDots' .
8332: BoolVal = 'Yes' / 'No' .
1.24 cvs 8333: StyleVal = 'Roman' / 'Italics' / 'Oblique' .
8334: WeightVal = 'Normal' / 'Bold' .
1.6 cvs 8335: FontVal = 'Times' / 'Helvetica' / 'Courier' .
8336: UnderLineVal = 'NoUnderline' / 'UnderLined' /
8337: 'OverLined' / 'CrossedOut' .
8338: ThicknessVal = 'Thick' / 'Thin' .
8339: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
8340: Pattern = NAME .
8341: Color = NAME .
8342: PresMinimum = NUMBER .
8343: PresMaximum = NUMBER .
1.1 cvs 8344: PresIntervalMin= NUMBER .
8345: PresIntervalMax= NUMBER .
1.6 cvs 8346: PresValue = [ '-' ] PresVal .
8347: PresVal = NUMBER .
1.1 cvs 8348:
1.6 cvs 8349: TextTransSeq = [ Alphabet ] TransSeq .
8350: Alphabet = NAME .
1.30 cvs 8351: TransSeq = 'BEGIN' < Translation > 'END' ';' /
1.6 cvs 8352: Translation .
1.30 cvs 8353: Translation = Source [ '->' Target ] ';' .
1.6 cvs 8354: Source = STRING .
1.18 cvs 8355: Target = STRING .</pre>
8356: </div>
1.37 ! cvs 8357: <hr />
1.18 cvs 8358: </div>
1.1 cvs 8359:
1.18 cvs 8360: <div class="chapter">
1.37 ! cvs 8361: <h1><a name="sect7" id="sect7">Character coding</a></h1>
1.1 cvs 8362:
1.18 cvs 8363: <div class="section">
1.37 ! cvs 8364: <h2><a name="sectb71" id="sectb71">Characters</a></h2>
1.1 cvs 8365:
1.37 ! cvs 8366: <p>The characters of the Latin alphabet follow the encoding defined in the
! 8367: ISO 8859-1 (ISO Latin-1) standard. The characters of the Greek alphabet
! 8368: follow the encoding defined by Adobe for its Symbol font (Adobe
! 8369: FontSpecific).</p>
! 8370:
! 8371: <p>Characters whose octal code is greater than 0200 are written in the form
! 8372: of their octal code preceded by a backslash character (``\''). For example,
! 8373: the French word 'Résumé' is written <tt>R\351sum\351</tt>.</p>
1.30 cvs 8374:
8375: <p>To the ISO 8859-1 encoding four characters with the following codes have
1.37 ! cvs 8376: been added:<br />
! 8377: <tt>212</tt>: line break<br />
! 8378: <tt>240</tt>: sticky space<br />
! 8379: <tt>201</tt>: thin space<br />
1.18 cvs 8380: <tt>202</tt>: en space</p>
1.30 cvs 8381:
8382: <p>The <tt>212</tt> character is a ``line break'' character which forces a
1.37 ! cvs 8383: line break. The <tt>240</tt> character is a ``sticky space'', which cannot be
1.18 cvs 8384: replaced by a line break.</p>
8385: </div>
1.1 cvs 8386:
1.18 cvs 8387: <div class="section">
1.37 ! cvs 8388: <h2><a name="sectb72" id="sectb72">Symbols</a></h2>
1.1 cvs 8389:
1.37 ! cvs 8390: <p>The table below gives the codes for the symbols of Thot. Symbols can be
! 8391: used in presentation schemas constants and in transcoding rules of
! 8392: translation schemas. Each symbol is represented by a single character.</p>
1.18 cvs 8393: <ul>
1.30 cvs 8394: <li><tt>r</tt>: a radical</li>
8395: <li><tt>i</tt>: a simple integral</li>
8396: <li><tt>c</tt>: a curvilinear integral</li>
8397: <li><tt>d</tt>: a double integral</li>
8398: <li><tt>t</tt>: a triple integral</li>
8399: <li><tt>S</tt>: the summation symbol</li>
8400: <li><tt>P</tt>: the product symbol</li>
8401: <li><tt>U</tt>: the union symbol</li>
8402: <li><tt>I</tt>: the intersection symbol</li>
8403: <li><tt>></tt>: a right arrow</li>
8404: <li><tt><</tt>: a left arrow</li>
1.37 ! cvs 8405: <li><tt>^</tt>: an up arrow</li>
1.30 cvs 8406: <li><tt>V</tt>: a down arrow</li>
8407: <li><tt>(</tt>: an opening parenthesis</li>
8408: <li><tt>)</tt>: a closing parenthesis</li>
8409: <li><tt>{</tt>: an opening brace</li>
8410: <li><tt>}</tt>: a closing brace</li>
8411: <li><tt>[</tt>: an opening bracket</li>
8412: <li><tt>]</tt>: a closing bracket</li>
1.18 cvs 8413: </ul>
8414: </div>
1.1 cvs 8415:
1.18 cvs 8416: <div class="section">
1.37 ! cvs 8417: <h2><a name="sectb73" id="sectb73">Graphical elements</a></h2>
1.1 cvs 8418:
1.30 cvs 8419: <p>The table below gives the codes for the graphical elements of Thot. These
1.1 cvs 8420: elements can be used in presentation schemas constants and in transcoding
1.37 ! cvs 8421: rules of translation schemas. Each graphical element is represented by a
1.18 cvs 8422: single character.</p>
8423: <ul>
1.30 cvs 8424: <li>a: a circle</li>
8425: <li><p><tt>A</tt>: an open curve with an arrow head at the end</p>
8426: </li>
8427: <li><tt>b</tt>: a horizontal line along the lower side of the box</li>
8428: <li><tt>B</tt>: an open curve</li>
8429: <li><tt>c</tt>: an ellipse inscribed in the box</li>
8430: <li><tt>C</tt>: a rectangle with rounded corners</li>
8431: <li><tt>D</tt>: an open curve with two arrow heads</li>
8432: <li><tt>e</tt>: The northwest/southeast diagonal of the box with an
8433: arrowhead at the bottom</li>
8434: <li><tt>E</tt>: The southwest/northeast diagonal of the box with an
8435: arrowhead at the top</li>
8436: <li><tt>F</tt>: an open curve with an arrow head at start</li>
8437: <li><tt>g</tt>: a line from the origin of the box to its opposite
8438: corner</li>
8439: <li><tt>h</tt>: a horizontal line as wide as the box and placed in its
8440: middle</li>
8441: <li><tt>l</tt>: a vertical line on the left side of the box</li>
8442: <li><tt>L</tt>: a lozenge</li>
8443: <li><tt>M</tt>: an open broken line with two arrow heads</li>
8444: <li><tt>N</tt>: an open broken line with an arrow head at start</li>
8445: <li><tt>o</tt>: The southwest/northeast diagonal of the box with an
8446: arrowhead at the bottom</li>
8447: <li><tt>O</tt>: The northwest/southeast diagonal of the box with an
8448: arrowhead at the top</li>
8449: <li><tt>p</tt>: a polygon</li>
8450: <li><tt>P</tt>: a rectangle with round corners and a horizontal bar at the
8451: top</li>
8452: <li><tt>Q</tt>: an ellipse with a horizontal bar at the top</li>
8453: <li><tt>r</tt>: a vertical line on the right side of the box</li>
8454: <li><tt>R</tt>: a rectangle which is the shape of the box</li>
8455: <li><tt>s</tt>: a closed curve</li>
8456: <li><tt>S</tt>: an open broken line</li>
8457: <li><tt>t</tt>: a horizontal line along the upper side of the box</li>
8458: <li><tt>U</tt>: an open broken line with an arrow head at the end</li>
8459: <li><tt>v</tt>: a vertical line as tall as the box and placed in its
8460: middle</li>
8461: <li><tt>V</tt>: a down arrow as tall as the box and in its middle</li>
8462: <li>w: a segment (2 points)</li>
8463: <li><tt>W</tt>: the upper right corner</li>
8464: <li>x: a segment (2 points) with an arrow head at the end</li>
8465: <li><tt>X</tt>: the lower right corner</li>
8466: <li>y: a segment (2 points) with an arrow head at the end</li>
8467: <li><tt>Y</tt>: the lower left corner</li>
8468: <li>z: a segment (2 points) with an arrow head at the end</li>
8469: <li><tt>Z</tt>: the upper left corner</li>
8470: <li><tt>space</tt>: a transparent element</li>
8471: <li><tt>^</tt>: an up arrow as tall as the box and in its middle</li>
8472: <li><tt>></tt>: a right arrow as long as the box's width and in its
8473: middle</li>
8474: <li><tt>></tt>: a left arrow as long as the box's width and in its
8475: middle</li>
8476: <li><tt>/</tt>: The southwest/northeast diagonal of the box</li>
8477: <li><tt>\</tt>: the northwest/southeast diagonal of the box</li>
1.18 cvs 8478: </ul>
1.37 ! cvs 8479: <hr />
1.18 cvs 8480: </div>
8481: </div>
8482: </body>
8483: </html>
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