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1.30 cvs 5: <title>The Languages of Thot</title>
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1.19 cvs 11: <div class="frontmatter" align="center">
1.18 cvs 12: <h1>The Languages of Thot</h1>
13:
14: <h3>Vincent Quint</h3>
15:
16: <h4>Translated from French by Ethan Munson</h4>
17:
1.32 ! cvs 18: <h4>Version of December 26, 2000</h4>
1.30 cvs 19:
20: <p>© 1996-2000 INRIA</p>
1.18 cvs 21: <hr>
22: </div>
23:
24: <div class="tableofcontents">
25: <h2><a href="languages.toc.html">Contents</a></h2>
26: <ul>
1.30 cvs 27: <li><big><a href="#sect2">The document model of Thot</a></big>
28: <ul>
29: <li><strong><a href="#sectb21">The logical structure of
30: documents</a></strong></li>
31: <li><strong><a href="#sectb22">Generic and specific
32: structures</a></strong></li>
33: <li><strong><a href="#sectb23">Logical structure and physical
34: structure</a></strong></li>
35: <li><strong><a href="#sectb24">Document structures and object
36: structures</a></strong></li>
37: </ul>
38: </li>
39: <li><big><a href="#sect3">The S language</a></big>
40: <ul>
41: <li><strong><a href="#sectb31">Document meta-structure</a></strong>
42: <ul>
43: <li><a href="#sectc311">The basic types</a></li>
44: <li><a href="#sectc312">Constructed elements</a></li>
45: <li><a href="#sectc313">Logical structure constructors</a>
46: <ul>
47: <li><small><a href="#sectd3131">Aggregate and
48: List</a></small></li>
49: <li><small><a href="#sectd3132">Choice, Schema, and
50: Unit</a></small></li>
51: <li><small><a href="#sectd3133">Reference and
52: Inclusion</a></small></li>
53: <li><small><a href="#sectd3134">Mark pairs</a></small></li>
54: <li><small><a href="#sectd3135">Restrictions and
55: Extensions</a></small></li>
56: <li><small><a href="#sectd3136">Summary</a></small></li>
57: </ul>
58: </li>
59: <li><a href="#sectc314">Associated Elements</a></li>
60: <li><a href="#sectc315">Attributes</a></li>
61: <li><a href="#sectc316">Discussion of the model</a></li>
62: </ul>
63: </li>
64: <li><strong><a href="#sectb32">The definition language for generic
65: structures</a></strong>
66: <ul>
67: <li><a href="#sectc321">Writing Conventions</a></li>
68: <li><a href="#sectc322">Extension schemas</a></li>
69: <li><a href="#sectc323">The general organization of structure
70: schemas</a></li>
71: <li><a href="#sectc324">The default presentation</a></li>
72: <li><a href="#sectc325">Global Attributes</a></li>
73: <li><a href="#sectc326">Parameters</a></li>
74: <li><a href="#sectc327">Structured elements</a></li>
75: <li><a href="#sectc328">Structure definitions</a>
76: <ul>
77: <li><small><a href="#sectd3281">List</a></small></li>
78: <li><small><a href="#sectd3282">Aggregate</a></small></li>
79: <li><small><a href="#sectd3283">Choice</a></small></li>
80: <li><small><a href="#sectd3284">Reference</a></small></li>
81: <li><small><a href="#sectd3285">Mark pairs</a></small></li>
82: </ul>
83: </li>
84: <li><a href="#sectc329">Imports</a></li>
85: <li><a href="#sectc3210">Extension rules</a></li>
86: <li><a href="#sectc3211">Associated elements</a></li>
87: <li><a href="#sectc3212">Units</a></li>
88: <li><a href="#sectc3213">Skeleton elements</a></li>
89: <li><a href="#sectc3214">Exceptions</a></li>
90: </ul>
91: </li>
92: <li><strong><a href="#sectb33">Some examples</a></strong>
93: <ul>
94: <li><a href="#sectc331">A class of documents: articles</a></li>
95: <li><a href="#sectc332">A class of objects: mathematical
96: formulas</a></li>
97: </ul>
98: </li>
99: </ul>
100: </li>
101: <li><big><a href="#sect4">The P language</a></big>
102: <ul>
103: <li><strong><a href="#sectb41">Document presentation</a></strong>
104: <ul>
105: <li><a href="#sectc411">Two levels of presentation</a></li>
106: <li><a href="#sectc412">Boxes</a></li>
107: <li><a href="#sectc413">Views and visibility</a></li>
108: <li><a href="#sectc414">Pages</a></li>
109: <li><a href="#sectc415">Numbering</a></li>
110: <li><a href="#sectc416">Presentation parameters</a></li>
111: </ul>
112: </li>
113: <li><strong><a href="#sectb42">Presentation description
114: language</a></strong>
115: <ul>
116: <li><a href="#sectc421">The organization of a presentation
117: schema</a></li>
118: <li><a href="#sectc422">Views</a></li>
119: <li><a href="#sectc423">Print Views</a></li>
120: <li><a href="#sectc424">Counters</a></li>
121: <li><a href="#sectc425">Presentation constants</a></li>
122: <li><a href="#sectc426">Variables</a></li>
123: <li><a href="#sectc427">Default presentation rules</a></li>
124: <li><a href="#sectc428">Presentation and page layout boxes</a></li>
125: <li><a href="#sectc429">Presentation of structured elements</a></li>
126: <li><a href="#sectc4210">Logical attribute presentation</a></li>
127: <li><a href="#sectc4212">Value transmission rules</a></li>
128: <li><a href="#sectc4213">Presentation rules</a></li>
129: <li><a href="#sectc4214">Conditions applying to presentation
130: rules</a>
131: <ul>
132: <li><small><a href="#sectd42141">Conditions based on the logical
133: position of the element</a></small></li>
134: <li><small><a href="#sectd42142">Conditions on
135: references</a></small></li>
136: <li><small><a href="#sectd42143">Conditions on logical
137: attributes</a></small></li>
138: <li><small><a href="#sectd42144">Conditions on page
139: breaks</a></small></li>
140: <li><small><a href="#sectd42145">Conditions on the element's
141: content</a></small></li>
142: <li><small><a href="#sectd42146">Conditions on
143: counters</a></small></li>
144: </ul>
145: </li>
146: <li><a href="#sectc4215">A presentation rule</a></li>
147: <li><a href="#sectc4216">Box axes</a></li>
148: <li><a href="#sectc4217">Distance units</a></li>
149: <li><a href="#sectc4218">Relative positions</a></li>
150: <li><a href="#sectc4219">Box extents</a>
151: <ul>
152: <li><small><a href="#sectd42191">Fixed extents</a></small></li>
153: <li><small><a href="#sectd42192">Relative
154: extents</a></small></li>
155: <li><small><a href="#sectd42193">Elastic
156: extents</a></small></li>
157: </ul>
158: </li>
159: <li><a href="#sectc4220">Overflow</a></li>
160: <li><a href="#sectc4221">Inheritance</a></li>
161: <li><a href="#sectc4222">Line breaking</a>
162: <ul>
163: <li><small><a href="#sectd42221">Line spacing</a></small></li>
164: <li><small><a href="#sectd42222">First line
165: indentation</a></small></li>
166: <li><small><a href="#sectd42223">Alignment</a></small></li>
167: <li><small><a href="#sectd42224">Justification</a></small></li>
168: <li><small><a href="#sectd42225">Hyphenation</a></small></li>
169: <li><small><a href="#sectd42226">Avoiding line
170: breaking</a></small></li>
171: </ul>
172: </li>
173: <li><a href="#sectc4223">Page breaking and line breaking
174: conditions</a></li>
175: <li><a href="#sectc4224">Visibility</a></li>
176: <li><a href="#sectc4225">Character style parameters</a>
177: <ul>
178: <li><small><a href="#sectd42251">Character size</a></small></li>
179: <li><small><a href="#sectd42252">Font and character
180: style</a></small></li>
181: <li><small><a href="#sectd42253">Underlining</a></small></li>
182: </ul>
183: </li>
184: <li><a href="#sectc4226">Stacking order</a></li>
185: <li><a href="#sectc4227">Line style</a></li>
186: <li><a href="#sectc4228">Line thickness</a></li>
187: <li><a href="#sectc4229">Fill pattern</a></li>
188: <li><a href="#sectc4230">Colors</a></li>
189: <li><a href="#sectc4230a">Background color and border</a></li>
190: <li><a href="#sectc4230b">Background pictures</a></li>
191: <li><a href="#sectc4231">Presentation box content</a></li>
192: <li><a href="#sectc4232">Presentation box creation</a></li>
193: <li><a href="#sectc4233">Page layout</a></li>
194: <li><a href="#sectc4234">Box copies</a></li>
195: </ul>
196: </li>
197: </ul>
198: </li>
199: <li><big><a href="#sect5">The T language</a></big>
200: <ul>
201: <li><strong><a href="#sectb51">Document translation</a></strong>
202: <ul>
203: <li><a href="#sectc511">Translation principles</a></li>
204: <li><a href="#sectc512">Translation procedure</a></li>
205: </ul>
206: </li>
207: <li><strong><a href="#sectb52">Translation definition
208: language</a></strong>
209: <ul>
210: <li><a href="#sectc521">Organization of a translation
211: schema</a></li>
212: <li><a href="#sectc522">Line length</a></li>
213: <li><a href="#sectc523">Buffers</a></li>
214: <li><a href="#sectc524">Counters</a></li>
215: <li><a href="#sectc525">Constants</a></li>
216: <li><a href="#sectc526">Variables</a></li>
217: <li><a href="#sectc527">Translating structure elements</a></li>
218: <li><a href="#sectc528">Conditional rules</a>
219: <ul>
220: <li><small><a href="#sectd5281">Conditions based on the logical
221: position of the element</a></small></li>
222: <li><small><a href="#sectd5282">Conditions on
223: references</a></small></li>
224: <li><small><a href="#sectd5283">Conditions on the
225: parameters</a></small></li>
226: <li><small><a href="#sectd5284">Conditions on the
227: alphabets</a></small></li>
228: <li><small><a href="#sectd5285">Conditions on page
229: breaks</a></small></li>
230: <li><small><a href="#sectd5286">Conditions on the element's
231: content</a></small></li>
232: <li><small><a href="#sectd5287">Conditions on the presence of
233: comments</a></small></li>
234: <li><small><a href="#sectd5288">Conditions on the presence of
235: specific presentation rules</a></small></li>
236: <li><small><a href="#sectd5289">Conditions on the presence of
237: logical attributes</a></small></li>
238: <li><small><a href="#sectd52810">Conditions on logical
239: attributes</a></small></li>
240: <li><small><a href="#sectd52811">Conditions on specific
241: presentation rules</a></small></li>
242: </ul>
243: </li>
244: <li><a href="#sectc529">Translation rules</a></li>
245: <li><a href="#sectc5210">The <tt>Create</tt> rule</a></li>
246: <li><a href="#sectc5211">The <tt>Write</tt> rule</a></li>
247: <li><a href="#sectc5212">The <tt>Read</tt> rule</a></li>
248: <li><a href="#sectc5213">The <tt>Include</tt> rule</a></li>
249: <li><a href="#sectc5214">The <tt>Get</tt> rule</a></li>
250: <li><a href="#sectc5215">The <tt>Copy</tt> rule</a></li>
251: <li><a href="#sectc5216">The <tt>Use</tt> rule</a></li>
252: <li><a href="#sectc5217">The <tt>Remove</tt> rule</a></li>
1.31 cvs 253: <li><a href="#sectc5217a">The <code>Ignore</code> rule</a></li>
1.30 cvs 254: <li><a href="#sectc5218">The <tt>NoTranslation</tt> rule</a></li>
255: <li><a href="#sectc5219">The <tt>NoLineBreak</tt> rule</a></li>
256: <li><a href="#sectc5220">The <tt>ChangeMainFile</tt> rule</a></li>
257: <li><a href="#sectc5220a">The <tt>RemoveFile</tt> rule</a></li>
258: <li><a href="#sectc5221">The <tt>Set</tt> and <tt>Add</tt>
259: rules</a></li>
260: <li><a href="#sectc5221a">The <tt>Indent</tt> rule</a></li>
261: <li><a href="#sectc5222">Rule application order</a></li>
262: <li><a href="#sectc5223">Translation of logical attributes</a></li>
263: <li><a href="#sectc5224">Translation of specific
264: presentations</a></li>
265: <li><a href="#sectc5225">Recoding of characters, symbols and
266: graphics</a></li>
267: </ul>
268: </li>
269: </ul>
270: </li>
271: <li><big><a href="#sect6">Language grammars</a></big>
272: <ul>
273: <li><strong><a href="#sectb61">The M meta-language</a></strong></li>
274: <li><strong><a href="#sectb62">The S language</a></strong></li>
275: <li><strong><a href="#sectb63">The P language</a></strong></li>
276: <li><strong><a href="#sectb64">The T language</a></strong></li>
277: </ul>
278: </li>
279: <li><big><a href="#sect7">Character coding</a></big>
280: <ul>
281: <li><strong><a href="#sectb71">Characters</a></strong></li>
282: <li><strong><a href="#sectb72">Symbols</a></strong></li>
283: <li><strong><a href="#sectb73">Graphical elements</a></strong></li>
284: </ul>
285: </li>
1.18 cvs 286: </ul>
287: <hr>
288: </div>
1.1 cvs 289:
1.18 cvs 290: <div class="chapter">
1.30 cvs 291: <h1><a name="sect2">The document model of Thot</a></h1>
1.1 cvs 292:
1.30 cvs 293: <p>All of the services which Thot provides to the user are based on the
294: system's internal document representation. This representation is itself
295: derived from the document model which underlies Thot. The model is presented
296: here, prior to the description of the languages which permit the generic
297: specification of documents.</p>
1.1 cvs 298:
1.18 cvs 299: <div class="section">
1.30 cvs 300: <h2><a name="sectb21">The logical structure of documents</a></h2>
1.1 cvs 301:
1.30 cvs 302: <p>The document model of Thot is primarily designed to allow the user to
303: operate on those entities which s/he has in mind when s/he works on a
304: document. The model makes no assumptions about the nature of these entities.
305: It is essentially these logical entities, such as paragraphs, sections,
306: chapters, notes, titles, and cross-references which give a document its
307: logical structure.</p>
308:
309: <p>Because of this model, the author can divide the document into chapters,
1.1 cvs 310: giving each one a title. The content of these chapters can be further divided
1.2 cvs 311: into sections, subsections, etc. The text is organized into successive
312: paragraphs, according to the content. In the writing phase, the lines, pages,
313: margins, spacing, fonts, and character styles are not very important. In fact,
314: if the system requires documents to be written in these terms, it gets in the
315: way. So, Thot's model is primarily based on the logical aspect of documents.
1.18 cvs 316: The creation of a model of this type essentially requires the definition :</p>
317: <ul>
1.30 cvs 318: <li>of the entities which can appear in the documents,</li>
319: <li>and the relations between these entities.</li>
1.18 cvs 320: </ul>
1.30 cvs 321:
322: <p>The choice of entities to include in the model can be subtle. Some
323: documents require chapters, while others only need various levels of sections.
324: Certain documents contain appendices, others don't. In different documents
325: the same logical entity may go by different names (e.g. ``Conclusion'' and
1.1 cvs 326: ``Summary''). Certain entities which are absolutely necessary in some
327: documents, such as clauses in a contract or the address of the recipient in a
1.18 cvs 328: letter, are useless in most other cases.</p>
1.30 cvs 329:
330: <p>The differences between documents result from more than just the entities
331: that appear in them, but also from the relationships between these entities
332: and the ways that they are linked. In certain documents, notes are spread
333: throughout the document, for example at the bottom of the page containing the
1.1 cvs 334: cross-reference to them, while in other documents they are collected at the
335: end of each chapter or even at the end of the work. As another example, the
336: introduction of some documents can contain many sections, while in other
337: documents, the introduction is restricted to be a short sequence of
1.18 cvs 338: paragraphs.</p>
1.30 cvs 339:
340: <p>All of this makes it unlikely that a single model can describe any document
341: at a relatively high level. It is obviously tempting to make up a list of
342: widely used entities, such as chapters, sections, paragraphs, and titles, and
343: then map all other entities onto the available choices. In this way, an
1.1 cvs 344: introduction can be supported as a chapter and a contract clause supported as
345: a paragraph or section. However, in trying to widen the range of usage of
346: certain entities, their meaning can be lost and the power of the model
347: reduced. In addition, while this widening partially solves the problem of
348: choosing entities, it does not solve the problem of their organization: when a
349: chapter must be composed of sections, how does one indicate that an
350: introduction has none when it is merely another chapter? One solution is to
351: include introductions in the list of supported entities. But then, how does
352: one distinguish those introductions which are allowed to have sections from
353: those which are not. Perhaps this could be done by defining two types of
354: introduction. Clearly, this approach risks an infinite expansion of the list
1.18 cvs 355: of widely used entities.</p>
356: </div>
1.1 cvs 357:
1.18 cvs 358: <div class="section">
1.30 cvs 359: <h2><a name="sectb22">Generic and specific structures</a></h2>
1.1 cvs 360:
1.30 cvs 361: <p>Thus, it is apparently impossible to construct an exhaustive inventory of
362: all those entities which are necessary and sufficient to precisely describe
363: any document. It also seems impossible to specify all possible arrangements of
1.18 cvs 364: these entities in a document. This is why Thot uses a <em>meta-model</em>
365: instead, which permits the description of numerous <em>models</em>, each one
366: describing a <em>class</em> of documents.</p>
1.30 cvs 367:
368: <p>A <em>class</em> is a set of documents having very similar structure. Thus,
1.1 cvs 369: the collection of research reports published by a laboratory constitutes a
370: class; the set of commercial proposals by the sales department of a company
371: constitutes another class; the set of articles published by a journal
372: constitutes a third class. Clearly, it is not possible to enumerate every
373: possible document class. It is also clear that new document classes must be
1.18 cvs 374: created to satisfy new needs and applications.</p>
1.30 cvs 375:
376: <p>To give a more rigorous definition of classes, we must introduce the ideas
377: of <em>generic structure</em> and <em>specific structure</em>. Each document
378: has a <em>specific structure</em> which organizes the various parts which
379: comprise it. We illustrate this with the help of a simple example comparing
380: two reports, A and B (<a href="#specstruct">see Figure</a>). The report A
381: contains an introduction followed by three chapters and a conclusion. The
382: first chapter contains two sections, the second, three sections. That is the
1.18 cvs 383: <em>specific</em> structure of document A. Similarly, the structure of
1.1 cvs 384: document B is: an introduction, two chapters, a conclusion; Chapter 1 has
385: three sections while Chapter 2 has four. The specific structures of these two
1.18 cvs 386: documents are thus different.</p>
1.1 cvs 387:
1.18 cvs 388: <div class="figure">
389: <hr>
390: <pre> Report A Report B
1.1 cvs 391: Introduction Introduction
392: Chapter 1 Chapter 1
393: Section 1.1 Section 1.1
394: Section 1.2 Section 1.2
395: Chapter 2 Section 1.3
396: Section 2.1 Chapter 2
397: Section 2.2 Section 2.1
398: Section 2.3 Section 2.2
399: Chapter 3 Section 2.3
400: Conclusion Section 2.4
1.18 cvs 401: Conclusion</pre>
1.30 cvs 402:
403: <p align="center"><em><a name="specstruct">Two specific
404: structures</a></em></p>
1.18 cvs 405: <hr>
1.30 cvs 406: </div>
407:
408: <p>The <em>generic structure</em> defines the ways in which specific
409: structures can be constructed. It specifies how to generate specific
410: structures. The reports A and B, though different, are constructed in
411: accordance with the same generic structure, which specifies that a report
412: contains an introduction followed by a variable number of chapters and a
413: conclusion, with each chapter containing a variable number of sections.</p>
414:
415: <p>There is a one-to-one correspondence between a class and a generic
416: structure: all the documents of a class are constructed in accordance with the
417: same generic structure. Hence the definition of the class: a class is a set
418: of documents whose specific structure is constructed in accordance with the
419: same generic structure. A class is characterized by its generic
420: structure.</p>
1.19 cvs 421:
1.30 cvs 422: <p>Thus, a generic structure can be considered to be a model at the level
423: which interests us, but only for one class of documents. When the definition
424: is limited to a single class of documents, it is possible to define a model
425: which does a good job of representing the documents of the class, including
426: the necessary entities and unencumbered by useless entities. The description
427: of the organization of the documents in the class can then be sufficiently
1.18 cvs 428: precise.</p>
429: </div>
1.1 cvs 430:
1.18 cvs 431: <div class="section">
1.30 cvs 432: <h2><a name="sectb23">Logical structure and physical structure</a></h2>
1.1 cvs 433:
1.30 cvs 434: <p>Generic structures only describe the <em>logical</em> organization of
1.18 cvs 435: documents, not their <em>physical</em> presentation on a screen or on sheets
1.1 cvs 436: of paper. However, for a document to be displayed or printed, its graphic
1.18 cvs 437: presentation must be taken into account.</p>
1.30 cvs 438:
439: <p>An examination of current printed documents shows that the details of
1.1 cvs 440: presentation essentially serve to bring out their logical structure. Outside
441: of some particular domains, notably advertising, the presentation is rarely
442: independent of the logical organization of the text. Moreover, the art of
443: typography consists of enhancing the organization of the text being set,
444: without catching the eye of the reader with overly pronounced effects. Thus,
445: italic and boldface type are used to emphasize words or expressions which have
446: greater significance than the rest of the text: keywords, new ideas,
447: citations, book titles, etc. Other effects highlight the organization of the
448: text: vertical space, margin changes, page breaks, centering, eventually
449: combined with the changes in the shapes or weight of the characters. These
450: effects serve to indicate the transitions between paragraphs, sections, or
451: chapters: an object's level in the logical structure of the document is shown
1.18 cvs 452: by the markedness of the effects.</p>
1.30 cvs 453:
454: <p>Since the model permits the description of all of the logical structure of
455: the document, the presentation can be derived from the model without being
1.1 cvs 456: submerged in the document itself. It suffices to use the logical structure of
457: the document to make the desired changes in its presentation: changes in type
1.18 cvs 458: size, type style, spacing, margin, centering, etc.</p>
1.30 cvs 459:
460: <p>Just as one cannot define a unique generic logical structure for all
461: document classes, one cannot define universal presentation rules which can be
462: applied to all document classes. For certain types of documents the chapter
463: titles will be centered on the page and printed in large, bold type. For
464: other documents, the same chapter titles will be printed in small, italic type
465: and aligned on the left margin.</p>
466:
467: <p>Therefore, it is necessary to base the presentation specifications for
1.1 cvs 468: documents on their class. Such a specification can be very fine-grained,
469: because the presentation is expressed in terms of the entities defined in the
470: generic logical structure of the class. Thus, it is possible to specify a
471: different presentation for the chapter titles and the section titles, and
472: similarly to specify titles for the sections according to their level in the
473: section hierarchy. The set of rules which specify the presentation of all the
1.18 cvs 474: elements defined in a generic logical structure is called a <em>generic
475: presentation</em>.</p>
1.30 cvs 476:
477: <p>There are several advantages derived from having a presentation linked to
478: the generic structure and described by a generic presentation. Homogeneity is
479: the first. Since every document in a class corresponds to the same generic
1.1 cvs 480: logical structure, a homogenous presentation for different documents of the
481: same class can be assured by applying the same generic presentation to all
482: documents of the class. Homogeneity of presentation can also be found among
1.2 cvs 483: the entities of a single document: every section heading will be presented in
1.1 cvs 484: the same way, the first line of every paragraph of the same type will have the
1.18 cvs 485: same indentation, etc.</p>
1.30 cvs 486:
487: <p>Another advantage of this approach to presentation is that it facilitates
1.1 cvs 488: changes to the graphical aspect of documents. A change to the generic
489: presentation rules attached to each type of entity will alter the presentation
490: of the entire document, and will do so homogenously. In this case, the
491: internal homogeneity of the class is no longer assured, but the way to control
492: it is simple. It suffices to adopt a single generic presentation for the
1.18 cvs 493: entire class.</p>
1.30 cvs 494:
495: <p>If the presentation of the class does not have to be homogenous, then the
1.1 cvs 496: appearance of the document can be adapted to the way it will be used or to the
497: device used to render it. This quality is sufficient to allow the existence
1.18 cvs 498: of <a name="mulpres">many generic presentations</a> for the same document
1.1 cvs 499: class. By applying one or the other of these presentations to it, the document
500: can be seen under different graphical aspects. It must be emphasized that
501: this type of modification of the presentation is not a change to the document
502: itself (in its specific logical structure or its content), but only in its
1.18 cvs 503: appearance at the time of editing or printing.</p>
504: </div>
1.1 cvs 505:
1.18 cvs 506: <div class="section">
1.30 cvs 507: <h2><a name="sectb24">Document structures and object structures</a></h2>
1.1 cvs 508:
1.30 cvs 509: <p>So far, we have only discussed the global structure of documents and have
510: not considered the contents found in that structure. We could limit ourselves
511: to purely textual contents by assuming that a title or a paragraph contains a
1.1 cvs 512: simple linear text. But this model would be too restrictive. In fact,
513: certain documents contain not only text, but also contain tables, diagrams,
514: photographs, mathematical formulas, and program fragments. The model must
1.18 cvs 515: permit the representation of such <em>objects</em>.</p>
1.30 cvs 516:
517: <p>Just as with the whole of the document, the model takes into account the
1.1 cvs 518: logical structure of objects of this type. Some are clearly structured,
519: others are less so. Logical structure can be recognized in mathematical
520: formulas, in tables, and in certain types of diagrams. On the other hand, it
521: is difficult to define the structure of a photograph or of some drawings. But
522: in any case, it does not seem possible to define one unique structure which
523: can represent every one of these types of objects. The approach taken in the
524: definition of meta-structure and document classes also applies to objects.
525: Object classes can be defined which put together objects of similar type,
1.18 cvs 526: constructed from the same generic logical structure.</p>
1.30 cvs 527:
528: <p>Thus, a mathematical class can be defined and have a generic logical
529: structure associated with it. But even if a single generic structure can
530: represent a sufficient variety of mathematical formulas, for other objects
531: with less rigorous structure, multiple classes must be defined. As for
532: documents, using multiple classes assures that the model can describe the full
533: range of objects to be presented. It also permits the system to support
534: objects which were not initially anticipated. Moreover, this comment applies
535: equally to mathematics: different classes of formulas can be described
536: depending on the domain of mathematics being described.</p>
537:
538: <p>Since objects have the same level of logical representation as documents,
539: they gain the same advantages. In particular, it is possible to define the
1.1 cvs 540: presentation separately from the objects themselves and attach it to the
541: class. Thus, as for documents, objects of the same type have a uniform
542: presentation and the presentation of every object in a given class can be
543: changed simply by changing the generic presentation of the class. Another
544: advantage of using this document model is that the system does not bother the
545: user with the details of presentation, but rather allows the user to
1.18 cvs 546: concentrate on the logical aspect of the document and the objects.</p>
1.30 cvs 547:
548: <p>It is clear that the documents in a class do not necessarily use the same
1.1 cvs 549: classes of objects: one technical report will contain tables while another
550: report will have no tables but will use mathematical formulas. The usable
1.2 cvs 551: object classes are not always mentioned in a limiting way in the generic
552: logical structure of documents. Rather, they can be chosen freely from a
1.18 cvs 553: large set, independent of the document class.</p>
1.30 cvs 554:
555: <p>Thus, the object classes will be made commonplace and usable in every
1.1 cvs 556: document. The notion of ``object'' can be enlarged to include not only
557: non-textual elements, but also certain types of textual elements which can
558: appear in practically every document, whatever their class. Among these
1.2 cvs 559: textual elements, one can mention enumerations, descriptions, examples,
1.18 cvs 560: quotations, even paragraphs.</p>
1.30 cvs 561:
562: <p>Thus, the document model is not a single, general model describing every
563: type of document in one place. Rather, it is a meta-model which can be used
564: to describe many different models each of which represents either a class of
1.1 cvs 565: similar documents or a class of similar objects which every document can
1.18 cvs 566: include.</p>
567: </div>
568: <hr>
569: </div>
1.1 cvs 570:
1.18 cvs 571: <div class="chapter">
572: <h1><a name="sect3">The S language</a></h1>
1.1 cvs 573:
1.18 cvs 574: <div class="section">
1.30 cvs 575: <h2><a name="sectb31">Document meta-structure</a></h2>
1.1 cvs 576:
1.30 cvs 577: <p>Since the concept of meta-structure is well suited to the task of
578: describing documents at a high level of abstraction, this meta-structure must
579: be precisely defined. Toward that end this section first presents the basic
1.1 cvs 580: elements from which documents and structured objects are composed and then
581: specifies the ways in which these basic elements are assembled into structures
1.18 cvs 582: representing complete documents and objects.</p>
1.1 cvs 583:
1.18 cvs 584: <div class="subsection">
1.30 cvs 585: <h3><a name="sectc311">The basic types</a></h3>
1.1 cvs 586:
1.30 cvs 587: <p>At the lowest level of a document's structure, the first atom considered is
1.1 cvs 588: the character. However, since characters are seldom isolated, usually
589: appearing as part of a linear sequence, and in order to reduce the complexity
1.18 cvs 590: of the document structure, <em>character strings</em> are used as atoms and
1.1 cvs 591: consecutive characters belonging to the same structural element are grouped in
1.18 cvs 592: the same character string.</p>
1.30 cvs 593:
594: <p>If the structure of a document is not refined to go down to the level of
1.1 cvs 595: words or phrases, the contents of a simple paragraph can be considered to be a
596: single character string. On the other hand, the title of a chapter, the title
597: of the first section of that chapter, and the text of the first paragraph of
598: that section constitute three different character strings, because they belong
1.18 cvs 599: to distinct structural elements.</p>
1.30 cvs 600:
601: <p>If, instead, a very fine-grained representation for the structure of a
1.1 cvs 602: document is sought, character strings could be defined to contain only a
603: single word, or even just a single character. This is the case, for example,
604: in programs, for which one wants to retain a structure very close to the
1.2 cvs 605: syntax of the programming language. In this case, an assignment statement
1.1 cvs 606: initializing a simple variable to zero would be composed of two structural
607: elements, the identifier of the variable (a short character string) and the
1.18 cvs 608: assigned value (a string of a single character, `0').</p>
1.30 cvs 609:
610: <p>The character string is not the only atom necessary for representing those
1.1 cvs 611: documents that interest us. It suffices for purely textual documents, but as
612: soon as the non-textual objects which we have considered arise, there must be
613: other atoms; the number of objects which are to be represented determines the
1.18 cvs 614: number of types of atoms that are necessary.</p>
1.30 cvs 615:
616: <p>Primitive <em>graphical elements</em> are used for tables and figures of
1.1 cvs 617: different types. These elements are simple geometric shapes like horizontal
618: or vertical lines, which are sufficient for tables, or even oblique lines,
1.2 cvs 619: arrows, rectangles, circles, polygons, and curves for use in figures. From
620: these elements and character strings, graphical objects and tables can be
1.18 cvs 621: constructed.</p>
1.30 cvs 622:
623: <p>Photographs, though having very little structure, must still appear in
1.18 cvs 624: documents. They are supported by <em>picture</em> elements, which are
625: represented as matrices of pixels.</p>
1.30 cvs 626:
627: <p>Finally, mathematical notations require certain elements which are
1.18 cvs 628: simultaneously characters and graphical elements, the <em>symbols</em>. By way
1.2 cvs 629: of example, radicals, integration signs, or even large parentheses are
1.1 cvs 630: examples of this type of atom. The size of each of these symbols is
631: determined by its environment, that is to say, by the expression to which it
1.18 cvs 632: is attached.</p>
1.30 cvs 633:
634: <p>To summarize, the primitive elements which are used in the construction of
1.18 cvs 635: documents and structured objects are:</p>
636: <ul>
1.30 cvs 637: <li>character strings,</li>
638: <li>graphical elements,</li>
639: <li>pictures,</li>
640: <li>and mathematical symbols.</li>
1.18 cvs 641: </ul>
642: </div>
1.1 cvs 643:
1.18 cvs 644: <div class="subsection">
1.30 cvs 645: <h3><a name="sectc312">Constructed elements</a></h3>
646:
647: <p>A document is evidently formed from primitive elements. But the model of
648: Thot also proposes higher level elements. Thus, in a document composed of
649: several chapters, each chapter is an element, and in the chapters each section
650: is also an element, and so on. A document is thus an organized set of
651: elements.</p>
1.1 cvs 652:
1.30 cvs 653: <p>In a document there are different sorts of elements. Each element has a
1.18 cvs 654: <em>type</em> which indicates the role of the element within the document as a
1.1 cvs 655: whole. Thus, we have, for example, the chapter and section types. The
656: document is made up of typed elements: elements of the type chapter and
657: elements of the type section, among others, but also character string elements
658: and graphical elements: the primitive elements are typed elements just as
659: well. At the other extreme, the document itself is also considered to be a
1.18 cvs 660: typed element.</p>
1.30 cvs 661:
662: <p>The important difference between the primitive elements and the other
663: elements of the document is that the primitive elements are atoms (they cannot
664: be decomposed), whereas the others, called <em>constructed elements</em>, are
1.1 cvs 665: composed of other elements, which can either be primitive elements or
666: constructed elements. A constructed element of type chapter (or more simply,
667: ``a chapter'') is composed of sections, which are also constructed elements. A
668: paragraph, a constructed element, can be made up of character strings, which
1.18 cvs 669: are primitive elements, and of equations, which are constructed elements.</p>
1.30 cvs 670:
671: <p>A document is also a constructed element. This is an important point. In
1.1 cvs 672: particular, it allows a document to be treated as part of another document,
673: and conversely, permits a part of a document to be treated as a complete
674: document. Thus, an article presented in a journal is treated by its author as
675: a document in itself, while the editor of the journal considers it to be part
676: of an issue. A table or a figure appearing in a document can be extracted and
677: treated as a complete document, for example to prepare transparencies for a
1.18 cvs 678: conference.</p>
1.30 cvs 679:
680: <p>These thoughts about types and constructed elements apply just as well to
1.1 cvs 681: objects as they do to documents. A table is a constructed element made up of
682: other constructed elements, rows and columns. A row is formed of cells, which
683: are also constructed elements which contain primitive elements (character
1.18 cvs 684: strings) and/or constructed elements like equations.</p>
685: </div>
1.1 cvs 686:
1.18 cvs 687: <div class="subsection">
1.30 cvs 688: <h3><a name="sectc313">Logical structure constructors</a></h3>
1.1 cvs 689:
1.30 cvs 690: <p>Having defined the primitive elements and the constructed elements, it is
691: now time to define the types of organization which allow the building of
1.18 cvs 692: structures. For this, we rely on the notion of the <em>constructor</em>. A
1.1 cvs 693: constructor defines a way of assembling certain elements in a structure. It
694: resides at the level of the meta-structure: it does not describe the existing
695: relations in a given structure, but rather defines how elements are assembled
1.18 cvs 696: to build a structure that conforms to a model.</p>
1.30 cvs 697:
698: <p>In defining the overall organization of documents, the first two
699: constructors considered are the aggregate and the list.</p>
1.1 cvs 700:
1.18 cvs 701: <div class="subsubsection">
1.30 cvs 702: <h4><a name="sectd3131">Aggregate and List</a></h4>
1.1 cvs 703:
1.30 cvs 704: <p>The <em>aggregate</em> constructor is used to define constructed element
705: types which are collections of a given number of other elements. These
706: collections may or may not be ordered. The elements may be either constructed
707: or primitive and are specified by their type. A report (that is, a
708: constructed element of the report type) has an aggregate structure. It is
709: formed from a title, an author's name, an introduction, a body, and a
710: conclusion, making it a collection of five element types. This type of
711: constructor is found in practically every document, and generally at several
712: levels in a document.</p>
713:
714: <p>The <em>list</em> constructor is used to define constructed elements which
715: are ordered sequences of elements (constructed or primitive) having the same
716: type. The minimum and maximum numbers of elements for the sequence can be
717: specified in the list constructor or the number of elements can be left
718: unconstrained. The body of a report is a list of chapters and is typically
719: required to contain a minimum of two chapters (is a chapter useful if it is
720: the only one in the report?) The chapter itself can contain a list of
721: sections, each section containing a list of paragraphs. In the same way as
722: the aggregate, the list is a very frequently used constructor in every type of
723: document. However, these two constructors are not sufficient to describe every
724: document structure; thus other constructors supplement them.</p>
1.18 cvs 725: </div>
1.1 cvs 726:
1.18 cvs 727: <div class="subsubsection">
1.30 cvs 728: <h4><a name="sectd3132">Choice, Schema, and Unit</a></h4>
1.1 cvs 729:
1.30 cvs 730: <p>The <em>choice</em> constructor is used to define the structure of an
731: element type for which one alternative is chosen from several possibilities.
732: Thus, a paragraph can be either a simple text paragraph, or an enumeration, or
733: a citation.</p>
734:
735: <p>The choice constructor indicates the complete list of possible options,
736: which can be too restrictive in certain cases, the paragraph being one such
737: case. Two constructors, <em>unit</em> and <em>schema</em>, address this
1.1 cvs 738: inconvenience. They allow more freedom in the choice of an element type. If
739: a paragraph is defined by a schema constructor, it is possible to put in the
740: place of a paragraph a table, an equation, a drawing or any other object
741: defined by another generic logical structure. It is also possible to define a
742: paragraph as a sequence of units, which could be character strings, symbols,
1.2 cvs 743: or pictures. The choice constructor alone defines a generic logical structure
1.1 cvs 744: that is relatively constrained; in contrast, using units and schemas, a very
1.18 cvs 745: open structure can be defined.</p>
1.30 cvs 746:
747: <p>The <em>schema</em> constructor represents an object defined by a generic
1.18 cvs 748: logical structure chosen freely from among those available.</p>
1.30 cvs 749:
750: <p>The <em>unit</em> constructor represents an element whose type can be
751: either a primitive type or an element type defined as a unit in the generic
752: logical structure of the document, or in another generic logical structure
753: used in the document. Such an element may be used in document objects
754: constructed according to other generic structures.</p>
755:
756: <p>Thus, for example, if a cross-reference to a footnote is defined in the
1.1 cvs 757: generic logical structure ``Article'' as a unit, a table (an object defined by
758: another generic structure) can contain cross-references to footnotes, when
759: they appear in an article. In another type of document, a table defined by
760: the same generic structure can contain other types of elements, depending on
761: the type of document into which the table is inserted. All that is needed is
762: to declare, in the generic structure for tables, that the contents of cells
763: are units. In this way, the generic structure of objects is divided up
764: between different types of documents which are able to adapt themselves to the
1.18 cvs 765: environment into which they are inserted.</p>
766: </div>
1.1 cvs 767:
1.18 cvs 768: <div class="subsubsection">
1.30 cvs 769: <h4><a name="sectd3133">Reference and Inclusion</a></h4>
1.1 cvs 770:
1.30 cvs 771: <p>The <em>reference</em> is used to define document elements that are
1.18 cvs 772: cross-references to other elements, such as a section, a chapter, a
773: bibliographic citation, or a figure. The reference is bi-directional. It can
774: be used to access both the element being cross-referenced and each of the
775: elements which make use of the cross-reference.</p>
1.30 cvs 776:
777: <p>References can be either <em>internal</em> or <em>external</em>. That is,
1.1 cvs 778: they can designate elements which appear in the same document or in another
1.18 cvs 779: document.</p>
1.30 cvs 780:
781: <p>The <em><a name="inclusion">inclusion</a></em> constructor is a special
782: type of reference. Like the reference, it is an internal or external
783: bidirectional link, but it is not a cross-reference. This link represents the
784: ``live'' inclusion of the designated element; it accesses the most recent
785: version of that element and not a ``dead'' copy, fixed in the state in which
786: it was found at the moment the copy was made. As soon as an element is
787: modified, all of its inclusions are automatically brought up to date. It must
788: be noted that, in addition to inclusion, Thot permits the creation of ``dead''
789: copies.</p>
790:
791: <p>There are three types of inclusions: inclusions with full expansion,
1.1 cvs 792: inclusions with partial expansion, and inclusions without expansion. During
793: editing, inclusions without expansion are represented on the screen by the
794: name of the included document, in a special color, while inclusions with
795: expansion (full or partial) are represented by a copy (full or partial) of the
796: included element (also in a special color). The on-screen representation of a
1.18 cvs 797: partial inclusion is a <a href="#sectc3213">``skeleton''</a> image of the
798: included document.</p>
1.30 cvs 799:
800: <p>Inclusion with complete expansion can be used to include parts of the same
1.1 cvs 801: document or of other documents. Thus, it can be either an internal or an
802: external link. It can be used to include certain bibliographic entries of a
803: scientific article in another article, or to copy part of a mathematical
804: formula into another formula of the same document, thus assuring that both
1.18 cvs 805: copies will remain synchronized.</p>
1.30 cvs 806:
807: <p>Inclusion without expansion or with partial expansion is used to include
1.1 cvs 808: complete documents. It is always an external link. It is used primarily to
809: divide very large documents into sub-documents that are easier to manipulate,
810: especially when there are many authors. So, a book can include some chapters,
811: where each chapter is a different document which can be edited separately.
812: When viewing the book on the screen, it might be desirable to see only the
813: titles of the chapters and sections. This can be achieved using inclusion
1.18 cvs 814: with partial expansion.</p>
1.30 cvs 815:
816: <p>During printing, inclusions without expansion or with partial expansion can
817: be represented either as they were shown on the screen or by a complete (and
1.18 cvs 818: up-to-date) copy of the included element or document.</p>
1.30 cvs 819:
820: <p>The inclusion constructor, whatever its type, respects the generic
821: structure: only those elements authorized by the generic structure can be
822: included at a given position in a document.</p>
1.18 cvs 823: </div>
1.1 cvs 824:
1.18 cvs 825: <div class="subsubsection">
1.30 cvs 826: <h4><a name="sectd3134">Mark pairs</a></h4>
1.1 cvs 827:
1.30 cvs 828: <p>It is often useful to delimit certain parts of a document independently
829: from the logical structure. For example, one might wish to attach some
830: information (in the form of an <a href="#sectc315">attribute</a>) or a
831: particular treatment to a group of words or a set of consecutive paragraphs.
832: <em>Mark pairs</em> are used to do this.</p>
833:
834: <p>Mark pairs are elements which are always paired and are terminals in the
1.1 cvs 835: logical structure of the document. Their position in the structure of the
836: document is defined in the generic structure. It is important to note that
1.18 cvs 837: when the terminals of a mark pair are <em>extensions</em> (see the next
838: section), they can be used quite freely.</p>
839: </div>
1.1 cvs 840:
1.18 cvs 841: <div class="subsubsection">
1.30 cvs 842: <h4><a name="sectd3135">Restrictions and Extensions</a></h4>
1.1 cvs 843:
1.30 cvs 844: <p>The primitive types and the constructors presented so far permit the
1.1 cvs 845: definition of the logical structure of documents and objects in a rigorous
846: way. But this definition can be very cumbersome in certain cases, notably
847: when trying to constrain or extend the authorized element types in a
1.18 cvs 848: particular context. <em>Restrictions</em> and <em>extensions</em> are used to
849: cope with these cases.</p>
1.30 cvs 850:
851: <p>A restriction associates with a particular element type <em>A</em>, a list
852: of those element types which elements of type <em>A</em> may not contain, even
853: if the definition of type <em>A</em> and those of its components authorize
854: them otherwise. This simplifies the writing of generic logical structures and
1.1 cvs 855: allows limitations to be placed, when necessary, on the choices offered by the
1.18 cvs 856: schema and unit constructors.</p>
1.30 cvs 857:
858: <p>Extensions are the inverse of restrictions. They identify a list of
859: element types whose presence <em>is</em> permitted, even if its definition and
860: those of its components do not authorize them otherwise.</p>
1.18 cvs 861: </div>
862:
863: <div class="subsubsection">
1.30 cvs 864: <h4><a name="sectd3136">Summary</a></h4>
1.18 cvs 865:
1.30 cvs 866: <p>Thus, four constructors are used to construct a document:</p>
1.18 cvs 867: <ul>
1.30 cvs 868: <li>the aggregate constructor (ordered or not),</li>
869: <li>the list constructor,</li>
870: <li>the choice constructor and its extensions, the unit and schema
871: constructors,</li>
872: <li>the reference constructor and its variant, the inclusion.</li>
873: </ul>
874:
875: <p>These constructors are also sufficient for objects. Thus, these
876: constructors provide a homogenous meta-model which can describe both the
877: organization of the document as a whole and that of the various types of
878: objects which it contains. After presenting the description language for
879: generic structures, we will present several examples which illustrate the
880: appropriateness of the model.</p>
881:
882: <p>The first three constructors (aggregate, list and choice) lead to tree-like
1.1 cvs 883: structures for documents and objects, the objects being simply the subtrees of
884: the tree of a document (or even of other objects' subtrees). The reference
885: constructor introduces other, non-hierarchical, relations which augment those
886: of the tree: when a paragraph makes reference to a chapter or a section, that
887: relation leaves the purely tree-like structure. Moreover, external reference
888: and inclusion constructors permit the establishment of links between different
1.18 cvs 889: documents, thus creating a hypertext structure.</p>
890: </div>
891: </div>
1.1 cvs 892:
1.18 cvs 893: <div class="subsection">
1.30 cvs 894: <h3><a name="sectc314">Associated Elements</a></h3>
1.1 cvs 895:
1.30 cvs 896: <p>Thanks to the list, aggregate and choice constructors, the organization of
897: the document is specified rigorously, using constructed and primitive
898: elements. But a document is made up of more than just its elements; it clearly
899: also contains links between them. There exist elements whose position in the
1.1 cvs 900: document's structure is not determinable. This is notably the case for
901: figures and notes. A figure can be designated at many points in the same
902: document and its place in the physical document can vary over the life of the
903: document without any effect on the meaning or clarity of the document. At one
904: time, it can be placed at the end of the document along with all other
905: figures. At another time, it can appear at the top of the page which follows
906: the first mention of the figure. The figures can be dispersed throughout the
907: document or can be grouped together. The situation is similar for notes,
908: which can be printed at the bottom of the page on which they are mentioned or
909: assembled together at the end of the chapter or even the end of the work. Of
910: course, this brings up questions of the physical position of elements in
911: documents that are broken into pages, but this reflects the structural
912: instability of these elements. They cannot be treated the same way as
913: elements like paragraphs or sections, whose position in the structure is
1.18 cvs 914: directly linked to the semantics of the document.</p>
1.30 cvs 915:
916: <p>Those elements whose position in the structure of the document is not
917: fixed, even though they are definitely part of the document, are called
1.18 cvs 918: <em>associated elements</em>. Associated elements are themselves structures,
1.1 cvs 919: which is to say that their content can be organized logically by the
1.18 cvs 920: constructors from primitive and constructed elements.</p>
1.30 cvs 921:
922: <p>It can happen that the associated elements are totally disconnected from
923: the structure of the document, as in a commentary or appraisal of the entire
924: work. But more often, the associated elements are linked to the content of the
1.1 cvs 925: document by references. This is generally the case for notes and figures,
1.18 cvs 926: among others.</p>
1.30 cvs 927:
928: <p>Thus, associated elements introduce a new use for the reference
929: constructor. It not only serves to create links between elements of the
930: principal structure of the document, but also serves to link the associated
931: elements to the primary structure.</p>
1.18 cvs 932: </div>
1.1 cvs 933:
1.18 cvs 934: <div class="subsection">
1.30 cvs 935: <h3><a name="sectc315">Attributes</a></h3>
1.1 cvs 936:
1.30 cvs 937: <p>There remain logical aspects of documents that are not entirely described
938: by the structure. Certain types of semantic information, which are not stated
1.1 cvs 939: explicitly in the text, must also be taken into account. In particular, such
940: information is shown by typographic effects which do not correspond to a
941: change between structural elements. In fact, certain titles are set in bold
942: or italic or are printed in a different typeface from the rest of the text in
943: order to mark them as structurally distinct. But these same effects
944: frequently appear in the middle of continuous text (e.g. in the interior of a
945: paragraph). In this case, there is no change between structural elements; the
946: effect serves to highlight a word, expression, or phrase. The notion of an
1.18 cvs 947: <em>attribute</em> is used to express this type of information.</p>
1.30 cvs 948:
949: <p>An attribute is a piece of information attached to a structural element
950: which augments the type of the element and clarifies its function in the
951: document. Keywords, foreign language words, and titles of other works can all
952: be represented by character strings with attached attributes. Attributes may
1.1 cvs 953: also be attached to constructed elements. Thus, an attribute indicating the
954: language can be attached to a single word or to a large part of a
1.18 cvs 955: document.</p>
1.30 cvs 956:
957: <p>In fact, an attribute can be any piece of information which is linked to a
1.1 cvs 958: part of a document and which can be used by agents which work on the document.
959: For example, the language in which the document is written determines the set
960: of characters used by an editor or formatter. It also determines the
961: algorithm or hyphenation dictionary to be used. The attribute ``keyword''
962: facilitates the work of an information retrieval system. The attribute
963: ``index word'' allows a formatter to automatically construct an index at the
1.18 cvs 964: end of the document.</p>
1.30 cvs 965:
966: <p>As with the types of constructed elements, the attributes and the values
967: they can take are defined separately in each generic logical structure, not in
968: the meta-model, according to the needs of the document class or the nature of
969: the object.</p>
970:
971: <p>Many types of attributes are offered: numeric, textual, references, and
1.18 cvs 972: enumerations:</p>
973: <ul>
1.30 cvs 974: <li><em>Numeric attributes</em> can take integer values (negative, positive,
975: or null).</li>
976: <li><em>Textual attributes</em> have as their values character strings.</li>
977: <li><em>Reference attributes</em> designate an element of the logical
978: structure.</li>
979: <li><em>Enumeration attributes</em> can take one value from a limited list
980: of possible values, each value being a name.</li>
1.18 cvs 981: </ul>
1.30 cvs 982:
983: <p>In a generic structure, there is a distinction between <em>global
1.18 cvs 984: attributes</em> and <em>local attributes</em>. A global attribute can be
1.1 cvs 985: applied to every element type defined in the generic structure where it is
986: specified. In contrast, a local attribute can only be applied to certain
987: types of elements, even only a single type. The ``language'' attribute
988: presented above is an example of a global attribute. An example of a local
989: attribute is the rank of an author (principal author of the document or
990: secondary author): this attribute can only be applied sensibly to an element
1.18 cvs 991: of the ``author'' type.</p>
1.30 cvs 992:
993: <p>Attributes can be assigned to the elements which make up the document in
994: many different ways. The author can freely and dynamically place them on any
995: part of the document in order to attach supplementary information of his/her
1.18 cvs 996: choice. However, attributes may only be assigned in accordance with the rules
997: of the generic structure; in particular, local attributes can only be assigned
998: to those element types for which they are defined.</p>
1.30 cvs 999:
1000: <p>In the generic structure, certain local attributes can be made mandatory
1001: for certain element types. In this case, Thot automatically associates the
1.2 cvs 1002: attribute with the elements of this type and it requires the user to provide a
1.18 cvs 1003: value for this attribute.</p>
1.30 cvs 1004:
1005: <p>Attributes can also be automatically assigned, with a given value, by every
1.1 cvs 1006: application processing the document in order to systematically add a piece of
1007: information to certain predefined elements of the document. By way of
1008: example, in a report containing a French abstract and an English abstract,
1009: each of the two abstracts is defined as a sequence of paragraphs. The first
1010: abstract has a value of ``French'' for the ``language'' attribute while the
1.18 cvs 1011: second abstract's ``language'' attribute has a value of ``English''.</p>
1.30 cvs 1012:
1013: <p>In the case of mark pairs, attributes are logically associated with the
1014: pair as a whole, but are actually attached to the first mark.</p>
1.18 cvs 1015: </div>
1.1 cvs 1016:
1.18 cvs 1017: <div class="subsection">
1.30 cvs 1018: <h3><a name="sectc316">Discussion of the model</a></h3>
1.1 cvs 1019:
1.30 cvs 1020: <p>The notions of attribute, constructor, structured element, and associated
1.1 cvs 1021: element are used in the definition of generic logical structures of documents
1022: and objects. The problem is to assemble them to form generic structures. In
1023: fact, many types of elements and attributes can be found in a variety of
1024: generic structures. Rather than redefine them for each structure in which
1025: they appear, it is best to share them between structures. The object classes
1026: already fill this sharing function. If a mathematical class is defined, its
1027: formulas can be used in many different document classes, without redefining
1028: the structure of each class. This problem arises not only for the objects
1029: considered here; it also arises for the commonplace textual elements found in
1030: many document classes. This is the reason why the notion of object is so
1031: broad and why paragraphs and enumerations are also considered to be objects.
1032: These object classes not only permit the sharing of the structures of
1.18 cvs 1033: elements, but also of the attributes defined in the generic structures.</p>
1.30 cvs 1034:
1035: <p>Structure, such as that presented here, can appear very rigid, and it is
1.1 cvs 1036: possible to imagine that a document editing system based on this model could
1037: prove very constraining to the user. This is, in fact, a common criticism of
1038: syntax-directed editors. This defect can be avoided with Thot, primarily for
1.18 cvs 1039: three reasons:</p>
1040: <ul>
1.30 cvs 1041: <li>the generic structures are not fixed in the model itself,</li>
1042: <li>the model takes the dynamics of documents into account,</li>
1043: <li>the constructors offer great flexibility.</li>
1.18 cvs 1044: </ul>
1.30 cvs 1045:
1046: <p>When the generic structure of a document is not predefined, but rather is
1.1 cvs 1047: constructed specifically for each document class, it can be carefully adapted
1048: to the current needs. In cases where the generic structure is inadequate for
1049: a particular document of the class, it is always possible either to create a
1050: new class with a generic structure well suited to the new case or to extend
1051: the generic structure of the existing class to take into account the specifics
1052: of the document which poses the problem. These two solutions can also be
1.18 cvs 1053: applied to objects whose structures prove to be poorly designed.</p>
1.30 cvs 1054:
1055: <p>The model is sufficiently flexible to take into account all the phases of
1056: the life of the document. When a generic structure specifies that a report
1057: must contain a title, an abstract, an introduction, at least two chapters, and
1058: a conclusion, this means only that a report, <em>upon completion</em>, will
1059: have to contain all of these elements. When the author begins writing, none
1060: of these elements is present. Thot uses this model. Therefore, it tolerates
1.2 cvs 1061: documents which do not conform strictly to the generic structure of their
1062: class; it also considers the generic logical structure to be a way of helping
1.18 cvs 1063: the user in the construction of a complex document.</p>
1.30 cvs 1064:
1065: <p>In contrast, other applications may reject a document which does not
1066: conform strictly to its generic structure. This is, for example, what is done
1067: by compilers which refuse to generate code for a program which is not
1.1 cvs 1068: syntactically correct. This might also occur when using a document
1.18 cvs 1069: application for a report which does not have an abstract or title.</p>
1.30 cvs 1070:
1071: <p>The constructors of the document model bring a great flexibility to the
1.1 cvs 1072: generic structures. A choice constructor (and even more, a unit or schema
1073: constructor) can represent several, very different elements. The list
1074: constructor permits the addition of more elements of the same type. Used
1075: together, these two constructors permit any series of elements of different
1076: types. Of course, this flexibility can be reduced wherever necessary since a
1077: generic structure can limit the choices or the number of elements in a
1.18 cvs 1078: list.</p>
1.30 cvs 1079:
1080: <p>Another difficulty linked to the use of structure in the document model
1.1 cvs 1081: resides in the choice of the level of the structure. The structure of a
1082: discussion could be extracted from the text itself via linguistic analysis.
1083: Some studies are exploring this approach, but the model of Thot excludes this
1084: type of structure. It only takes into account the logical structure provided
1.18 cvs 1085: explicitly by the author.</p>
1.30 cvs 1086:
1087: <p>However, the level of structure of the model is not imposed. Each generic
1.1 cvs 1088: structure defines its own level of structure, adapted to the document class or
1089: object and to the ways in which it will be processed. If it will only be
1090: edited and printed, a relatively simple structure suffices. If more
1091: specialized processing will be applied to it, the structure must represent the
1092: element types on which this processing must act. By way of example, a simple
1093: structure is sufficient for printing formulas, but a more complex structure is
1094: required to perform symbolic or numeric calculations on the mathematical
1.18 cvs 1095: expressions. The document model of Thot allows both types of structure.</p>
1096: </div>
1097: </div>
1.1 cvs 1098:
1.18 cvs 1099: <div class="section">
1.30 cvs 1100: <h2><a name="sectb32">The definition language for generic structures</a></h2>
1.1 cvs 1101:
1.30 cvs 1102: <p>Generic structures, which form the basis of the document model of Thot, are
1.1 cvs 1103: specified using a special language. This definition language, called S, is
1.18 cvs 1104: described in this section.</p>
1.30 cvs 1105:
1106: <p>Each generic structure, which defines a class of documents or objects, is
1.2 cvs 1107: specified by a file, written in the S language, which is called a
1.18 cvs 1108: <em>structure schema</em>. Structure schemas are compiled into tables, called
1109: structure tables, which are used by Thot and which determine its behavior.</p>
1.1 cvs 1110:
1.18 cvs 1111: <div class="subsection">
1.30 cvs 1112: <h3><a name="sectc321">Writing Conventions</a></h3>
1.1 cvs 1113:
1.30 cvs 1114: <p>The grammar of S, like those of the languages P and T presented later, is
1.1 cvs 1115: described using the meta-language M, derived from the Backus-Naur Form
1.18 cvs 1116: (BNF).</p>
1.30 cvs 1117:
1118: <p>In this meta-language each rule of the grammar is composed of a grammar
1119: symbol followed by an equals sign (`=') and the right part of the rule. The
1120: equals sign plays the same role as the traditional `::=' of BNF: it indicates
1121: that the right part defines the symbol of the left part. In the right
1122: part,</p>
1.18 cvs 1123: <dl>
1.30 cvs 1124: <dt>concatenation</dt>
1125: <dd>is shown by the juxtaposition of symbols;</dd>
1126: <dt>character strings</dt>
1127: <dd>between apostrophes ' represent terminal symbols, that is, keywords in
1128: the language defined. Keywords are written here in upper-case letters,
1.31 cvs 1129: but can be written in any combination of upper and lower-case letters.
1.30 cvs 1130: For example, the keyword <tt>DEFPRES</tt> of S can also be written as
1131: <tt>defpres</tt> or <tt>DefPres</tt>.</dd>
1132: <dt>material between brackets</dt>
1133: <dd>(`[' and `]') is optional;</dd>
1134: <dt>material between angle brackets</dt>
1135: <dd>(`<' and `>') can be repeated many times or omitted;</dd>
1136: <dt>the slash</dt>
1137: <dd>(`/') indicates an alternative, a choice between the options separated
1138: by the slash character;</dd>
1139: <dt>the period</dt>
1140: <dd>marks the end of a rule;</dd>
1141: <dt>text between braces</dt>
1142: <dd>(`{' and `}') is simply a comment.</dd>
1.18 cvs 1143: </dl>
1.30 cvs 1144:
1145: <p>The M meta-language also uses the concepts of identifiers, strings, and
1.18 cvs 1146: integers:</p>
1147: <dl>
1.30 cvs 1148: <dt><tt>NAME</tt></dt>
1149: <dd>represents an identifier, a sequence of letters (upper or lower-case),
1150: digits, and underline characters (`_'), beginning with a letter. Also
1151: considered a letter is the sequence of characters `<tt>\nnn</tt>' where
1152: the letter <tt>n</tt> represents the ISO Latin-1 code of the letter in
1153: octal. It is thus possible to use accented letters in identifiers. The
1154: maximum length of identifiers is fixed by the compiler. It is normally
1155: 31 characters.
1156: <p>Unlike keywords, upper and lower-case letters are distinct in
1157: identifiers. Thus, <tt>Title</tt>, <tt>TITLE</tt>, and <tt>title</tt>
1158: are considered different identifiers.</p>
1159: </dd>
1160: <dt><tt>STRING</tt></dt>
1161: <dd>represents a string. This is a string of characters delimited by
1.31 cvs 1162: apostrophes. If an apostrophe must appear in a string, it is doubled. As
1163: with identifiers, strings can contain characters represented by their
1.30 cvs 1164: octal code (after a backslash). As with apostrophes, if a backslash
1165: must appear in a string, it is doubled.</dd>
1166: <dt><tt>NUMBER</tt></dt>
1167: <dd>represents a positive integer or zero (without a sign), or said
1168: another way, a sequence of decimal digits.</dd>
1.18 cvs 1169: </dl>
1.30 cvs 1170:
1171: <p>The M language can be used to define itself as follows:</p>
1.18 cvs 1172: <pre>{ Any text between braces is a comment. }
1.30 cvs 1173: Grammar = Rule < Rule > 'END' .
1174: { The < and > signs indicate zero }
1.1 cvs 1175: { or more repetitions. }
1176: { END marks the end of the grammar. }
1177: Rule = Ident '=' RightPart '.' .
1178: { The period indicates the end of a rule }
1179: RightPart = RtTerminal / RtIntermed .
1180: { The slash indicates a choice }
1181: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
1182: { Right part of a terminal rule }
1.30 cvs 1183: RtIntermed = Possibility < '/' Possibility > .
1.1 cvs 1184: { Right part of an intermediate rule }
1.30 cvs 1185: Possibility = ElemOpt < ElemOpt > .
1186: ElemOpt = Element / '[' Element < Element > ']' /
1187: '<' Element < Element > '>' .
1.1 cvs 1188: { Brackets delimit optional parts }
1189: Element = Ident / KeyWord .
1190: Ident = NAME .
1191: { Identifier, sequence of characters }
1192: KeyWord = STRING .
1193: { Character string delimited by apostrophes }
1.18 cvs 1194: END</pre>
1195: </div>
1.1 cvs 1196:
1.18 cvs 1197: <div class="subsection">
1.30 cvs 1198: <h3><a name="sectc322">Extension schemas</a></h3>
1.1 cvs 1199:
1.30 cvs 1200: <p>A structure schema defines the generic logical structure of a class of
1.1 cvs 1201: documents or objects, independent of the operations which can be performed on
1202: the documents. However, certain applications may require particular
1203: information to be represented by the structure for the documents that they
1204: operate on. Thus a document version manager will need to indicate in the
1205: document the parts which belong to one version or another. An indexing system
1206: will add highly-structured index tables as well as the links between these
1.18 cvs 1207: tables and the rest of the document.</p>
1.30 cvs 1208:
1209: <p>Thus, many applications need to extend the generic structure of the
1210: documents on which they operate to introduce new attributes, associated
1211: elements or element types. These additions are specific to each application
1212: and must be able to be applied to any generic structure: users will want to
1213: manage versions or construct indices for many types of documents. Extension
1214: schemas fulfill this role: they define attributes, elements, associated
1215: elements, units, etc., but they can only be used jointly with a structure
1216: schema that they complete. Otherwise, structure schemas can always be used
1217: without these extensions when the corresponding applications are not
1218: available.</p>
1.18 cvs 1219: </div>
1.1 cvs 1220:
1.18 cvs 1221: <div class="subsection">
1.30 cvs 1222: <h3><a name="sectc323">The general organization of structure schemas</a></h3>
1.1 cvs 1223:
1.30 cvs 1224: <p>Every structure schema begins with the keyword <tt>STRUCTURE</tt> and ends
1.18 cvs 1225: with the keyword <tt>END</tt>. The keyword <tt>STRUCTURE</tt> is followed by
1226: the keyword <tt>EXTENSION</tt> in the case where the schema defines an
1.1 cvs 1227: extension, then by the name of the generic structure which the schema defines
1228: (the name of the document or object class). The name of the structure is
1.18 cvs 1229: followed by a semicolon.</p>
1.30 cvs 1230:
1231: <p>In the case of a complete schema (that is, a schema which is not an
1.1 cvs 1232: extension), the definition of the name of the structure is followed by the
1233: declarations of the default presentation schema, the global attributes, the
1234: parameters, the structure rules, the associated elements, the units, the
1235: skeleton elements and the exceptions. Only the definition of the structure
1236: rules is required. Each series of declarations begins with a keyword:
1.18 cvs 1237: <tt>DEFPRES</tt>, <tt>ATTR</tt>, <tt>PARAM</tt>, <tt>STRUCT</tt>,
1238: <tt>ASSOC</tt>, <tt>UNITS</tt>, <tt>EXPORT</tt>, <tt>EXCEPT</tt>.</p>
1.30 cvs 1239:
1240: <p>In the case of an extension schema, there are neither parameters nor
1241: skeleton elements and the <tt>STRUCT</tt> section is optional, while that
1242: section is required in a schema that is not an extension. On the other hand,
1243: extension schemas can contain an <tt>EXTENS</tt> section, which must not
1244: appear in a schema which is not an extension; this section defines the
1245: complements to attach to the rules found in the schema to which the extension
1246: will be added. The sections <tt>ATTR</tt>, <tt>STRUCT</tt>, <tt>ASSOC</tt>,
1247: and <tt>UNITS</tt> define new attributes, new elements, new associated
1248: elements, and new units which add their definitions to the principal
1249: schema.</p>
1.18 cvs 1250: <pre> StructSchema ='STRUCTURE' ElemID ';'
1.1 cvs 1251: 'DEFPRES' PresID ';'
1252: [ 'ATTR' AttrSeq ]
1253: [ 'PARAM' RulesSeq ]
1254: 'STRUCT' RulesSeq
1255: [ 'ASSOC' RulesSeq ]
1256: [ 'UNITS' RulesSeq ]
1257: [ 'EXPORT' SkeletonSeq ]
1258: [ 'EXCEPT' ExceptSeq ]
1259: 'END' .
1.18 cvs 1260: ElemID = NAME .</pre>
1.30 cvs 1261:
1262: <p>or</p>
1.18 cvs 1263: <pre> ExtensSchema ='STRUCTURE' 'EXTENSION' ElemID ';'
1.1 cvs 1264: 'DEFPRES' PresID ';'
1265: [ 'ATTR' AttrSeq ]
1266: [ 'STRUCT' RulesSeq ]
1267: [ 'EXTENS' ExtensRuleSeq ]
1268: [ 'ASSOC' RulesSeq ]
1269: [ 'UNITS' RulesSeq ]
1270: [ 'EXCEPT' ExceptSeq ]
1271: 'END' .
1.18 cvs 1272: ElemID = NAME .</pre>
1273: </div>
1.1 cvs 1274:
1.18 cvs 1275: <div class="subsection">
1.30 cvs 1276: <h3><a name="sectc324">The default presentation</a></h3>
1.1 cvs 1277:
1.30 cvs 1278: <p>It was shown <a href="#mulpres">above</a> that many different presentations
1.1 cvs 1279: are possible for documents and objects of the same class. The structure
1.18 cvs 1280: schema defines a preferred presentation for the class, called the <em>default
1281: presentation</em>. Like generic structures, presentations are described by
1282: programs, called <em>presentation schemas</em>, which are written in a
1283: specific language, P, presented <a href="#sectb42">later</a> in this document.
1284: The name appearing after the keyword <tt>DEFPRES</tt> is the name of the
1.2 cvs 1285: default presentation schema. When a new document is created, Thot will use
1286: this presentation schema by default, but the user remains free to choose
1.18 cvs 1287: another if s/he wishes.</p>
1288: <pre> PresID = NAME .</pre>
1289: </div>
1.1 cvs 1290:
1.18 cvs 1291: <div class="subsection">
1.30 cvs 1292: <h3><a name="sectc325">Global Attributes</a></h3>
1.1 cvs 1293:
1.30 cvs 1294: <p>If the generic structure includes global attributes of its own, they are
1.18 cvs 1295: declared after the keyword <tt>ATTR</tt>. Each global attribute is defined by
1.1 cvs 1296: its name, followed by an equals sign and the definition of its type. The
1.18 cvs 1297: declaration of a global attribute is terminated by a semi-colon.</p>
1.30 cvs 1298:
1299: <p>For attributes of the numeric, textual, or reference types, the type is
1.18 cvs 1300: indicated by a keyword, <tt>INTEGER</tt>, <tt>TEXT</tt>, or <tt>REFERENCE</tt>
1301: respectively.</p>
1.30 cvs 1302:
1303: <p>In the case of a reference attribute, the keyword <tt>REFERENCE</tt> is
1.1 cvs 1304: followed by the type of the referenced element in parentheses. It can refer
1.18 cvs 1305: to any type at all, specified by using the keyword <tt>ANY</tt>, or to a
1.1 cvs 1306: specific type. In the latter case, the element type designated by the
1.18 cvs 1307: reference can be defined either in the <a href="#sectc327"><tt>STRUCT</tt>
1308: section</a> of the same structure schema or in the <tt>STRUCT</tt> section of
1.1 cvs 1309: another structure schema. When the type is defined in another schema, the
1310: element type is followed by the name of the structure schema (within
1311: parentheses) in which it is defined. The name of the designated element type
1.18 cvs 1312: can be preceded by the keyword <tt>First</tt> or <tt>Second</tt>, but only in
1313: the case where the type is defined as <a href="#sectd3285">a pair</a>. These
1.1 cvs 1314: keywords indicate whether the attribute must designate the first mark of the
1315: pair or the second. If the reference refers to a pair and neither of these
1.18 cvs 1316: two keywords is present, then the first mark is used.</p>
1.30 cvs 1317:
1318: <p>In the case of an enumeration attribute, the equals sign is followed by the
1.1 cvs 1319: list of names representing the possible values of the attribute, the names
1320: being separated from each other by commas. An enumeration attribute has at
1321: least one possible value; the maximum number of values is defined by the
1.18 cvs 1322: compiler for the S language.</p>
1.30 cvs 1323: <pre> AttrSeq = Attribute < Attribute > .
1.1 cvs 1324: Attribute = AttrID '=' AttrType ';' .
1325: AttrType = 'INTEGER' / 'TEXT' /
1326: 'REFERENCE' '(' RefType ')' /
1327: ValueSeq .
1328: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .
1329: FirstSec = 'First' / 'Second' .
1330: ExtStruct = '(' ElemID ')' .
1.30 cvs 1331: ValueSeq = AttrVal < ',' AttrVal > .
1.1 cvs 1332: AttrID = NAME .
1.18 cvs 1333: AttrVal = NAME .</pre>
1.30 cvs 1334:
1335: <p>There is a predefined global text attribute, the <em>language</em>, which
1336: is automatically added to every Thot structure schema. This attribute allows
1.2 cvs 1337: Thot to perform certain actions, such as hyphenation and spell-checking, which
1338: cannot be performed without knowing the language in which each part of the
1339: document is written. This attribute can be used just like any explicitly
1.18 cvs 1340: declared attribute: the system acts as if every structure schema contains</p>
1341: <pre>ATTR
1342: Language = TEXT;</pre>
1.30 cvs 1343:
1.18 cvs 1344: <blockquote class="example">
1.30 cvs 1345: <p><strong>Example:</strong></p>
1346:
1347: <p>The following specification defines the global enumeration attribute
1348: WordType.</p>
1349: <pre>ATTR
1.18 cvs 1350: WordType = Definition, IndexWord, DocumentTitle;</pre>
1351: </blockquote>
1352: </div>
1.1 cvs 1353:
1.18 cvs 1354: <div class="subsection">
1.30 cvs 1355: <h3><a name="sectc326">Parameters</a></h3>
1.1 cvs 1356:
1.30 cvs 1357: <p>A parameter is a document element which can appear many times in the
1358: document, but always has the same value. This value can only be modified in a
1.1 cvs 1359: controlled way by certain applications. For example, in an advertising
1360: circular, the name of the recipient may appear in the address part and in the
1361: text of the circular. If the recipient's name were a parameter, it might only
1.18 cvs 1362: be able to be changed by a ``mail-merge'' application.</p>
1.30 cvs 1363:
1364: <p>Parameters are not needed for every document class, but if the schema
1365: includes parameters they are declared after the keyword <tt>PARAM</tt>. Each
1366: parameter declaration is made in the same way as a <a
1367: href="#sectc327">structure element declaration</a>.</p>
1368:
1369: <p>During editing, Thot permits the insertion of parameters wherever the
1.1 cvs 1370: structure schema allows; it also permits the removal of parameters which are
1371: already in the document but does not allow the modification of the parameter's
1.2 cvs 1372: content in any way. The content is generated automatically by Thot during the
1373: creation of the parameter, based on the value of the parameter in the
1.18 cvs 1374: document.</p>
1375: </div>
1.1 cvs 1376:
1.18 cvs 1377: <div class="subsection">
1.30 cvs 1378: <h3><a name="sectc327">Structured elements</a></h3>
1.1 cvs 1379:
1.30 cvs 1380: <p>The rules for defining structured elements are required, except in an
1.1 cvs 1381: extension schema: they constitute the core of a structure schema, since they
1382: define the structure of the different types of elements that occur in a
1.18 cvs 1383: document or object of the class defined by the schema.</p>
1.30 cvs 1384:
1385: <p>The first structure rule after the keyword <tt>STRUCT</tt> must define the
1.1 cvs 1386: structure of the class whose name appears in the first instruction
1.18 cvs 1387: (<tt>STRUCTURE</tt>) of the schema. This is the root rule of the schema,
1388: defining the root of the document tree or object tree.</p>
1.30 cvs 1389:
1390: <p>The remaining rules may be placed in any order, since the language permits
1391: the definition of element types before or after their use, or even in the same
1.1 cvs 1392: instruction in which they are used. This last case allows the definition of
1.18 cvs 1393: recursive structures.</p>
1.30 cvs 1394:
1395: <p>Each rule is composed of a name (the name of the element type whose
1396: structure is being defined) followed by an equals sign and a structure
1397: definition.</p>
1398:
1399: <p>If any local attributes are associated with the element type defined by the
1.2 cvs 1400: rule, they appear between parentheses after the type name and before the
1.18 cvs 1401: equals sign. The parentheses contain, first, the keyword <tt>ATTR</tt>, then
1.2 cvs 1402: the list of local attributes, separated by commas. Each local attribute is
1403: composed of the name of the attribute followed by an equals sign and the
1.18 cvs 1404: definition of the attribute's type, just as in the definition of <a
1405: href="#sectc325">global attributes</a>. The name of the attribute can be
1.2 cvs 1406: preceded by an exclamation point to indicate that the attribute must always be
1407: present for this element type. The same attribute, identified by its name,
1408: can be defined as a local attribute for multiple element types. In this
1409: case, the equals sign and definition of the attribute type need only appear in
1410: the first occurrence of the attribute. It should be noted that global
1.18 cvs 1411: attributes cannot also be defined as local attributes.</p>
1.30 cvs 1412:
1413: <p>If any <a href="#sectd3135">extensions</a> are defined for this element
1414: type, a plus sign follows the structure definition and the names of the
1415: extension element types appear between parentheses after the plus. If there
1416: are multiple extensions, they are separated by commas. These types can either
1417: be defined in the same schema, defined in other schemas, or they may be base
1.18 cvs 1418: types identified by the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>,
1419: <tt>SYMBOL</tt>, or <tt>PICTURE</tt>.</p>
1.30 cvs 1420:
1421: <p><a href="#sectd3135">Restrictions</a> are indicated in the same manner as
1.18 cvs 1422: extensions, but they are introduced by a minus sign and they come after the
1423: extensions, or if there are no extensions, after the structure definition.</p>
1.30 cvs 1424:
1425: <p>If the values of attributes must be attached systematically to this element
1.18 cvs 1426: type, they are introduced by the keyword <tt>WITH</tt> and declared in the
1.1 cvs 1427: form of a list of fixed-value attributes. When such definitions of fixed
1.18 cvs 1428: attribute values appear, they are always the last part of the rule.</p>
1.30 cvs 1429:
1430: <p>The rule is terminated by a semicolon.</p>
1431: <pre> RuleSeq = Rule < Rule > .
1.1 cvs 1432: Rule = ElemID [ LocAttrSeq ] '=' DefWithAttr ';'.
1.30 cvs 1433: LocAttrSeq = '(' 'ATTR' LocAttr < ';' LocAttr > ')' .
1.1 cvs 1434: LocAttr = [ '!' ] AttrID [ '=' AttrType ] .
1435: DefWithAttr = Definition
1436: [ '+' '(' ExtensionSeq ')' ]
1437: [ '-' '(' RestrictSeq ')' ]
1438: [ 'WITH' FixedAttrSeq ] .
1.30 cvs 1439: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1.1 cvs 1440: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
1441: 'SYMBOL' / 'PICTURE' .
1.30 cvs 1442: RestrictSeq = RestrictElem < ',' RestrictElem > .
1.1 cvs 1443: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
1.18 cvs 1444: 'SYMBOL' / 'PICTURE' .</pre>
1.30 cvs 1445:
1446: <p>The list of fixed-value attributes is composed of a sequence of
1.1 cvs 1447: attribute-value pairs separated by commas. Each pair contains the name of the
1448: attribute and the fixed value for this element type, the two being separated
1449: by an equals sign. If the sign is preceded by a question mark the given value
1450: is only an initial value that may be modified later rather than a value fixed
1451: for all time. Reference attributes are an exception to this norm. They
1452: cannot be assigned a fixed value, but when the name of such an attribute
1453: appears this indicates that this element type must have a valid value for the
1.2 cvs 1454: attribute. For the other attribute types, the fixed value is indicated by a
1.1 cvs 1455: signed integer (numeric attributes), a character string between apostrophes
1.18 cvs 1456: (textual attributes) or the name of a value (enumeration attributes).</p>
1.30 cvs 1457:
1458: <p>Fixed-value attributes can either be <a href="#sectc325">global</a> or
1459: local to the element type for which they are fixed, but they must be declared
1460: before they are used.</p>
1461: <pre> FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 1462: FixedAttr = AttrID [ FixedOrModifVal ] .
1463: FixedOrModifVal = [ '?' ] '=' FixedValue .
1464: FixedValue = [ '-' ] NumValue / TextVal / AttrVal .
1465: NumValue = NUMBER .
1.18 cvs 1466: TextVal = STRING .</pre>
1467: </div>
1.1 cvs 1468:
1.18 cvs 1469: <div class="subsection">
1.30 cvs 1470: <h3><a name="sectc328">Structure definitions</a></h3>
1.1 cvs 1471:
1.30 cvs 1472: <p>The structure of an element type can be a simple base type or a constructed
1.18 cvs 1473: type.</p>
1.30 cvs 1474:
1475: <p>For constructed types, it is frequently the case that similar structures
1.1 cvs 1476: appear in many places in a document. For example the contents of the
1477: abstract, of the introduction, and of a section can have the same structure,
1478: that of a sequence of paragraphs. In this case, a single, common structure
1479: can be defined (the paragraph sequence in this example), and the schema is
1480: written to indicate that each element type possesses this structure, as
1.18 cvs 1481: follows:</p>
1482: <pre> Abstract = Paragraph_sequence;
1.1 cvs 1483: Introduction = Paragraph_sequence;
1.18 cvs 1484: Section_contents = Paragraph_sequence;</pre>
1.30 cvs 1485:
1486: <p>The equals sign means ``has the same structure as''.</p>
1487:
1488: <p>If the element type defined is a simple base type, this is indicated by one
1489: of the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>, <tt>SYMBOL</tt>, or
1.18 cvs 1490: <tt>PICTURE</tt>. If some local attributes must be associated with a base
1.1 cvs 1491: type, the keyword of the base type is followed by the declaration of the local
1.18 cvs 1492: attributes using the syntax <a href="#sectc327">presented above.</a></p>
1.30 cvs 1493:
1494: <p>In the case of an open choice, the type is indicated by the keyword
1.18 cvs 1495: <tt>UNIT</tt> for units or the keyword <tt>NATURE</tt> for objects having a
1496: structure defined by any other schema.</p>
1.30 cvs 1497:
1498: <p>A unit represents one of the two following categories:</p>
1.18 cvs 1499: <ul>
1.30 cvs 1500: <li>a base type: text, graphical element, symbol, picture,</li>
1501: <li>an element whose type is chosen from among the types defined as units in
1502: the <tt>UNITS</tt> section of the document's structure schema. It can
1503: also be chosen from among the types defined as <a
1504: href="#sectd3132">units</a> in the <a href="#sectc3212"><tt>UNITS</tt>
1505: section</a> of the structure schemas that defines the ancestors of the
1506: element to which the rule is applied.</li>
1.18 cvs 1507: </ul>
1.30 cvs 1508:
1509: <p>Before the creation of an element defined as a unit, Thot asks the user to
1.18 cvs 1510: choose between the categories of elements.</p>
1.30 cvs 1511:
1512: <p>Thus, the contents of a paragraph can be specified as a sequence of units,
1.1 cvs 1513: which will permit the inclusion in the paragraphs of character strings,
1514: symbols, and various elements, such as cross-references, if these are defined
1.18 cvs 1515: as units.</p>
1.30 cvs 1516:
1517: <p>A schema object (keyword <tt>NATURE</tt>) represents an object defined by a
1.1 cvs 1518: structure schema freely chosen from among the available schemas; in the case
1519: the element type is defined by the first rule (the root rule) of the chosen
1.18 cvs 1520: schema.</p>
1.30 cvs 1521:
1522: <p>If the element type defined is a constructed type, the list, aggregate,
1.1 cvs 1523: choice, and reference constructors are used. In this case the definition
1524: begins with a keyword identifying the constructor. This keyword is followed
1.18 cvs 1525: by a syntax specific to each constructor.</p>
1.30 cvs 1526:
1527: <p>The local attribute definitions appear after the name of the element type
1.18 cvs 1528: being defined, if this element type has <a href="#sectc327">local
1529: attributes</a>.</p>
1530: <pre> Definition = BaseType [ LocAttrSeq ] / Constr / Element .
1.1 cvs 1531: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' / 'PICTURE' /
1532: 'UNIT' / 'NATURE' .
1533: Element = ElemID [ ExtOrDef ] .
1534: ExtOrDef = 'EXTERN' / 'INCLUDED' /
1535: [ LocAttrSeq ] '=' Definition .
1536: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
1537: '(' DefWithAttr ')' /
1538: 'BEGIN' DefOptSeq 'END' /
1539: 'AGGREGATE' DefOptSeq 'END' /
1540: 'CASE' 'OF' DefSeq 'END' /
1541: 'REFERENCE' '(' RefType ')' /
1.18 cvs 1542: 'PAIR' .</pre>
1.1 cvs 1543:
1.18 cvs 1544: <div class="subsubsection">
1.30 cvs 1545: <h4><a name="sectd3281">List</a></h4>
1.1 cvs 1546:
1.30 cvs 1547: <p>The list constructor permits the definition of an element type composed of
1548: a list of elements, all of the same type. A list definition begins with the
1.18 cvs 1549: <tt>LIST</tt> keyword followed by an optional range, the keyword <tt>OF</tt>,
1.1 cvs 1550: and the definition, between parentheses, of the element type which must
1551: compose the list. The optional range is composed of the minimum and maximum
1552: number of elements for the list separated by two periods and enclosed by
1553: brackets. If the range is not present, the number of list elements is
1554: unconstrained. When only one of the two bounds of the range is unconstrained,
1555: it is represented by a star ('*') character. Even when both bounds are
1.18 cvs 1556: unconstrained, they can be specified by <tt>[*..*]</tt>, but it is simpler not
1557: to specify any bound.</p>
1558: <pre> 'LIST' [ '[' min '..' max ']' ]
1.1 cvs 1559: 'OF' '(' DefWithAttr ')'
1560: min = Integer / '*' .
1561: max = Integer / '*' .
1.18 cvs 1562: Integer = NUMBER .</pre>
1.30 cvs 1563:
1564: <p>Before the document is edited, Thot creates the minimum number of elements
1565: for the list. If no minimum was given, it creates a single element. If a
1566: maximum number of elements is given and that number is attained, the editor
1567: refuses to create new elements for the list.</p>
1568:
1569: <blockquote class="example">
1570: <p><strong>Example:</strong></p>
1571:
1572: <p>The following two instructions define the body of a document as a
1573: sequence of at least two chapters and the contents of a section as a
1574: sequence of paragraphs. A single paragraph can be the entire contents of a
1575: section.</p>
1576: <pre>Body = LIST [2..*] OF (Chapter);
1.18 cvs 1577: Section_contents = LIST OF (Paragraph);</pre>
1578: </blockquote>
1579: </div>
1.1 cvs 1580:
1.18 cvs 1581: <div class="subsubsection">
1.30 cvs 1582: <h4><a name="sectd3282">Aggregate</a></h4>
1.1 cvs 1583:
1.30 cvs 1584: <p>The aggregate constructor is used to define an element type as a collection
1585: of sub-elements, each having a fixed type. The collection may be ordered or
1.1 cvs 1586: unordered. The elements composing the collection are called
1.18 cvs 1587: <em>components</em>. In the definition of an aggregate, a keyword indicates
1588: whether or not the aggregate is ordered: <tt>BEGIN</tt> for an ordered
1589: aggregate, <tt>AGGREGATE</tt> for an unordered aggregate. This keyword is
1.1 cvs 1590: followed by the list of component type definitions which is terminated by the
1.18 cvs 1591: <tt>END</tt> keyword. The component type definitions are separated by
1592: commas.</p>
1.30 cvs 1593:
1594: <p>Before creating an aggregate, the Thot editor creates all the aggregate's
1.1 cvs 1595: components in the order they appear in the structure schema, even for
1596: unordered aggregates. However, unlike ordered aggregates, the components of
1597: an unordered aggregate may be rearranged using operations of the Thot editor.
1598: The exceptions to the rule are any components whose name was preceded by a
1599: question mark character ('?'). These components, which are optional, can be
1600: created by explicit request, possibly at the time the aggregate is created,
1.18 cvs 1601: but they are not created automatically <em>prior</em> to the creation of the
1602: aggregate.</p>
1603: <pre> 'BEGIN' DefOptSeq 'END'
1.30 cvs 1604: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.18 cvs 1605: DefOpt = [ '?' ] DefWithAttr .</pre>
1.30 cvs 1606:
1.18 cvs 1607: <blockquote class="example">
1.30 cvs 1608: <p><strong>Example:</strong></p>
1609:
1610: <p>In a bilingual document, each paragraph has an English version and a
1611: French version. In certain cases, the translator wants to add a marginal
1612: note, but this note is present in very few paragraphs. Thus, it must not be
1613: created systematically for every paragraph. A bilingual paragraph of this
1614: type is declared:</p>
1615: <pre>Bilingual_paragraph = BEGIN
1.1 cvs 1616: French_paragraph = TEXT;
1617: English_paragraph = TEXT;
1618: ? Note = TEXT;
1.18 cvs 1619: END;</pre>
1620: </blockquote>
1621: </div>
1.1 cvs 1622:
1.18 cvs 1623: <div class="subsubsection">
1.30 cvs 1624: <h4><a name="sectd3283">Choice</a></h4>
1.1 cvs 1625:
1.30 cvs 1626: <p>The choice constructor permits the definition of an element type which is
1.18 cvs 1627: chosen from among a set of possible types. The keywords <tt>CASE</tt> and
1628: <tt>OF</tt> are followed by a list of definitions of possible types, which are
1629: separated by semicolons and terminated by the <tt>END</tt> keyword.</p>
1630: <pre> 'CASE' 'OF' DefSeq 'END'
1.30 cvs 1631: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .</pre>
1632:
1633: <p>Before the creation of an element defined as a choice, the Thot editor
1.1 cvs 1634: presents the list of possible types for the element to the user. The user has
1.18 cvs 1635: only to select the element type that s/he wants to create from this list.</p>
1.30 cvs 1636:
1637: <p>The order of the type declarations is important. It determines the order
1638: of the list presented to the user before the creation of the element. Also,
1639: when a Choice element is being created automatically, the first type in the
1640: list is used. In fact, using the Thot editor, when an empty Choice element is
1.1 cvs 1641: selected, it is possible to select this element and to enter its text from
1642: keyboard. In this case, the editor uses the first element type which can
1.18 cvs 1643: contain an atom of the character string type.</p>
1.30 cvs 1644:
1645: <p>The two special cases of the choice constructor, the <a
1.18 cvs 1646: href="#sectc328"><em>schema</em></a> and the <a
1647: href="#sectc3212"><em>unit</em></a> are discussed elsewhere.</p>
1.30 cvs 1648:
1.18 cvs 1649: <blockquote class="example">
1.30 cvs 1650: <p><strong>Example:</strong></p>
1651:
1652: <p>It is common in documents to treat a variety of objects as if they were
1653: ordinary paragraphs. Thus, a ``Paragraph'' might actually be composed of a
1654: block of text (an ordinary paragraph), or a mathematical formula whose
1655: structure is defined by another structure schema named Math, or a table,
1656: also defined by another structure schema. Here is a definition of such a
1657: paragraph:</p>
1658: <pre>Paragraph = CASE OF
1.1 cvs 1659: Simple_text = TEXT;
1660: Formula = Math;
1661: Table_para = Table;
1.18 cvs 1662: END;</pre>
1663: </blockquote>
1664: </div>
1.1 cvs 1665:
1.18 cvs 1666: <div class="subsubsection">
1.30 cvs 1667: <h4><a name="sectd3284">Reference</a></h4>
1.1 cvs 1668:
1.30 cvs 1669: <p>Like all elements in Thot, references are typed. An element type defined
1670: as a reference is a cross-reference to an element of some other given type.
1671: The keyword <tt>REFERENCE</tt> is followed by the name of a type enclosed in
1.1 cvs 1672: parentheses. When the type which is being cross-referenced is defined in
1673: another structure schema, the type name is itself followed by the name of the
1.18 cvs 1674: external structure schema in which it is defined.</p>
1.30 cvs 1675:
1676: <p>When the designated element type is a <a href="#sectd3285">mark pair</a>,
1677: it can be preceded by a <tt>FIRST</tt> or <tt>SECOND</tt> keyword. These
1.18 cvs 1678: keywords indicate whether the reference points to the first or second mark of
1679: the pair. If the reference points to a pair and neither of these two keywords
1680: is present, the reference is considered to point to the first mark of the
1681: pair.</p>
1.30 cvs 1682:
1683: <p>There is an exception to the principle of typed references: it is possible
1684: to define a reference which designates an element of any type, which can
1685: either be in the same document or another document. In this case, it suffices
1686: to put the keyword <tt>ANY</tt> in the parentheses which indicate the
1687: referenced element type.</p>
1.18 cvs 1688: <pre> 'REFERENCE' '(' RefType ')'
1689: RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .</pre>
1.30 cvs 1690:
1691: <p>When defining an inclusion, the <tt>REFERENCE</tt> keyword is not used.
1.1 cvs 1692: Inclusions with complete expansion are not declared as such in the structure
1693: schemas, since any element defined in a structure schema can be replaced by an
1694: element of the same type. Instead, inclusions without expansion or with
1695: partial expansion must be declared explicitly whenever they will include a
1696: complete object ( and not a part of an object). In this case, the object type
1697: to be included (that is, the name of its structure schema) is followed by a
1.18 cvs 1698: keyword: <tt>EXTERN</tt> for inclusion without expansion and <tt>INCLUDED</tt>
1699: for partial expansion.</p>
1.30 cvs 1700:
1701: <p>Before creating a cross-reference or an inclusion, the Thot editor asks the
1.1 cvs 1702: user to choose, from the document images displayed, the referenced or included
1.18 cvs 1703: element.</p>
1.30 cvs 1704:
1.18 cvs 1705: <blockquote class="example">
1.30 cvs 1706: <p><strong>Example:</strong></p>
1707:
1708: <p>If the types Note and Section are defined in the Article structure
1709: schema, it is possible to define, in the same structure schema, a reference
1710: to a note and a reference to a section in this manner:</p>
1711: <pre>Ref_note = REFERENCE (Note);
1.18 cvs 1712: Ref_section = REFERENCE (Section);</pre>
1.30 cvs 1713:
1714: <p>It is also possible to define the generic structure of a collection of
1715: articles, which include (with partial expansion) objects of the Article
1716: class and which possess an introduction which may include cross-references
1717: to sections of the included articles. In the Collection structure schema,
1718: the definitions are:</p>
1719: <pre>Collection = BEGIN
1.6 cvs 1720: Collection_title = TEXT;
1721: Introduction = LIST OF (Elem = CASE OF
1.1 cvs 1722: TEXT;
1723: Ref_sect;
1724: END);
1.6 cvs 1725: Body = LIST OF (Article INCLUDED);
1726: END;
1.18 cvs 1727: Ref_sect = REFERENCE (Section (Article));</pre>
1.30 cvs 1728:
1729: <p>Here we define a Folder document class which has a title and includes
1730: documents of different types, particularly Folders:</p>
1731: <pre>Folder = BEGIN
1.6 cvs 1732: Folder_title = TEXT;
1733: Folder_contents = LIST OF (Document);
1734: END;
1.1 cvs 1735:
1736: Document = CASE OF
1737: Article EXTERN;
1738: Collection EXTERN;
1739: Folder EXTERN;
1.18 cvs 1740: END;</pre>
1.30 cvs 1741:
1742: <p>Under this definition, Folder represents either an aggregate which
1743: contains a folder title and the list of included documents or an included
1744: folder. To resolve this ambiguity, in the P language, the placement of a
1745: star character in front of the type name (here, Folder) indicates an
1746: included document.</p>
1.18 cvs 1747: </blockquote>
1748: </div>
1.1 cvs 1749:
1.18 cvs 1750: <div class="subsubsection">
1.30 cvs 1751: <h4><a name="sectd3285">Mark pairs</a></h4>
1.1 cvs 1752:
1.30 cvs 1753: <p>Like other elements, mark pairs are typed. The two marks of the pair have
1754: the same type, but there exist two predefined subtypes which apply to all mark
1.18 cvs 1755: pairs: the first mark of the pair (called <tt>First</tt> in the P and T
1756: languages) and the second mark (called <tt>Second</tt>).</p>
1.30 cvs 1757:
1758: <p>In the S language, a mark pair is noted simply by the <tt>PAIR</tt>
1.18 cvs 1759: keyword.</p>
1.30 cvs 1760:
1761: <p>In the Thot editor, marks are always moved or destroyed together. The two
1.1 cvs 1762: marks of a pair have the same identifier, unique within the document, which
1.18 cvs 1763: permits intertwining mark pairs without risk of ambiguity.</p>
1764: </div>
1765: </div>
1.1 cvs 1766:
1.18 cvs 1767: <div class="subsection">
1.30 cvs 1768: <h3><a name="sectc329">Imports</a></h3>
1.1 cvs 1769:
1.30 cvs 1770: <p>Because of schema constructors, it is possible, before editing a document,
1771: to use classes defined by other structure schemas whenever they are needed. It
1772: is also possible to assign specific document classes to certain element types.
1773: In this case, these classes are simply designated by their name. In fact, if
1774: a type name is not defined in the structure schema, it is assumed that it
1.18 cvs 1775: specifies a structure defined by another structure schema.</p>
1.30 cvs 1776:
1.18 cvs 1777: <blockquote class="example">
1.30 cvs 1778: <p><strong>Example:</strong></p>
1779:
1780: <p>If the types Math and Table don't appear in the left part of a structure
1781: rule in the schema, the following two rules indicate that a formula has the
1782: structure of an object defined by the structure schema Math and that a table
1783: element has the structure of an object defined by the Table schema.</p>
1784: <pre>Formula = Math;
1.18 cvs 1785: Table_elem = Table;</pre>
1786: </blockquote>
1787: </div>
1788:
1789: <div class="subsection">
1.30 cvs 1790: <h3><a name="sectc3210">Extension rules</a></h3>
1.18 cvs 1791:
1.30 cvs 1792: <p>The <tt>EXTENS</tt> section, which can only appear in an extension schema,
1.1 cvs 1793: defines complements to the rules in the primary schema (i.e. the structure
1794: schema to which the extension schema will be applied). More precisely, this
1795: section permits the addition to an existing type of local attributes,
1.18 cvs 1796: extensions, restrictions and fixed-value attributes.</p>
1.30 cvs 1797:
1798: <p>These additions can be applied to the root rule of the primary schema,
1.18 cvs 1799: designated by the keyword <tt>Root</tt>, or to any other explicitly named
1800: rule.</p>
1.30 cvs 1801:
1802: <p>Extension rules are separated from each other by a semicolon and each
1.18 cvs 1803: extension rule has the same syntax as a <a href="#sectc327">structure
1804: rule</a>, but the part which defines the constructor is absent.</p>
1.30 cvs 1805: <pre> ExtenRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.6 cvs 1806: ExtensRule = RootOrElem [ LocAttrSeq ]
1807: [ '+' '(' ExtensionSeq ')' ]
1808: [ '-' '(' RestrictSeq ')' ]
1809: [ 'WITH' FixedAttrSeq ] .
1.18 cvs 1810: RootOrElem = 'Root' / ElemID .</pre>
1811: </div>
1.1 cvs 1812:
1.18 cvs 1813: <div class="subsection">
1.30 cvs 1814: <h3><a name="sectc3211">Associated elements</a></h3>
1.1 cvs 1815:
1.30 cvs 1816: <p>If associated elements are necessary, they must be declared in a specific
1.18 cvs 1817: section of the structure schema, introduced by the keyword <tt>ASSOC</tt>.
1.1 cvs 1818: Each associated element type is specified like any other structured element.
1819: However, these types must not appear in any other element types of the schema,
1.18 cvs 1820: except in <tt>REFERENCE</tt> rules.</p>
1821: </div>
1.1 cvs 1822:
1.18 cvs 1823: <div class="subsection">
1.30 cvs 1824: <h3><a name="sectc3212">Units</a></h3>
1825:
1826: <p>The <tt>UNITS</tt> section of the structure schema contains the
1827: declarations of the element types which can be used in the external objects
1828: making up parts of the document or in objects of the class defined by the
1829: schema. As with associated elements, these element types are defined just
1830: like other structured element types. They can be used in the other element
1831: types of the schema, but they can also be used in any other rule of the
1832: schema.</p>
1833:
1834: <blockquote class="example">
1835: <p><strong>Example:</strong></p>
1.1 cvs 1836:
1.30 cvs 1837: <p>If references to notes are declared as units:</p>
1838: <pre>UNITS
1.18 cvs 1839: Ref_note = REFERENCE (Note);</pre>
1.30 cvs 1840:
1841: <p>then it is possible to use references to notes in a cell of a table, even
1842: when <tt>Table</tt> is an external structure schema. The <tt>Table</tt>
1843: schema must declare a cell to be a sequence of units, which can then be base
1844: element types (text, for example) or references to notes in the
1845: document.</p>
1846: <pre>Cell = LIST OF (UNITS);</pre>
1.18 cvs 1847: </blockquote>
1848: </div>
1.1 cvs 1849:
1.18 cvs 1850: <div class="subsection">
1.30 cvs 1851: <h3><a name="sectc3213">Skeleton elements</a></h3>
1.1 cvs 1852:
1.30 cvs 1853: <p>When editing a document which contains or must contain external references
1854: to several other documents, it may be necessary to load a large number of
1.1 cvs 1855: documents, simply to see the parts designated by the external references of
1856: the document while editing, or to access the source of included elements. In
1857: this case, the external documents are not modified and it is only necessary to
1858: see the elements of these documents which could be referenced. Because of
1859: this, the editor will suggest that the documents be loaded in ``skeleton''
1860: form. This form contains only the elements of the document explicitly
1.18 cvs 1861: mentioned in the <tt>EXPORT</tt> section of their structure schema and, for
1.1 cvs 1862: these elements, only the part of the contents specified in that section. This
1863: form has the advantage of being very compact, thus requiring very few
1864: resources from the editor. This is also the skeleton form which constitutes
1.18 cvs 1865: the expanded form of <a href="#inclusion">inclusions</a> with partial
1866: expansion.</p>
1.30 cvs 1867:
1868: <p>Skeleton elements must be declared explicitly in the <tt>EXPORT</tt>
1869: section of the structure schema that defines them. This section begins with
1870: the keyword <tt>EXPORT</tt> followed by a comma-separated list of the element
1.1 cvs 1871: types which must appear in the skeleton form and ending with a semicolon.
1.18 cvs 1872: These types must have been previously declared in the schema.</p>
1.30 cvs 1873:
1874: <p>For each skeleton element type, the part of the contents which is loaded by
1.1 cvs 1875: the editor, and therefore displayable, can be specified by putting the keyword
1.18 cvs 1876: <tt>WITH</tt> and the name of the contained element type to be loaded after
1.1 cvs 1877: the name of the skeleton element type. In this case only that named element,
1878: among all the elements contained in the exportable element type, will be
1.18 cvs 1879: loaded. If the <tt>WITH</tt> is absent, the entire contents of the skeleton
1.1 cvs 1880: element will be loaded by the editor. If instead, it is better that the
1881: skeleton form not load the contents of a particular element type, the keyword
1.18 cvs 1882: <tt>WITH</tt> must be followed by the word <tt>Nothing</tt>.</p>
1883: <pre> [ 'EXPORT' SkeletonSeq ]
1.1 cvs 1884:
1.30 cvs 1885: SkeletonSeq = SkelElem < ',' SkelElem > ';' .
1.1 cvs 1886: SkelElem = ElemID [ 'WITH' Contents ] .
1.18 cvs 1887: Contents = 'Nothing' / ElemID [ ExtStruct ] .</pre>
1.30 cvs 1888:
1.18 cvs 1889: <blockquote class="example">
1.30 cvs 1890: <p><strong>Example:</strong></p>
1891:
1892: <p>Suppose that, in documents of the article class, the element types
1893: Article_title, Figure, Section, Paragraph, and Biblio should appear in the
1894: skeleton form in order to make it easier to create external references to
1895: them from other documents. When loading an article in its skeleton form,
1896: all of these element types will be loaded except for paragraphs, but only
1897: the article title will be loaded in its entirety. For figures, the caption
1898: will be loaded, while for sections, the title will be loaded, and for
1.31 cvs 1899: bibliographic entries, only the title that they contain will be loaded. Note
1900: that bibliographic elements are defined in another structure schema, RefBib.
1.32 ! cvs 1901: To produce this result, the following declarations should be placed in the
1.31 cvs 1902: Article structure schema:</p>
1.30 cvs 1903: <pre>EXPORT
1.1 cvs 1904: Article_title,
1.5 cvs 1905: Figure With Caption,
1.1 cvs 1906: Section With Section_title,
1907: Paragraph With Nothing,
1.18 cvs 1908: Biblio With Biblio_title(RefBib);</pre>
1909: </blockquote>
1910: </div>
1.1 cvs 1911:
1.18 cvs 1912: <div class="subsection">
1.30 cvs 1913: <h3><a name="sectc3214">Exceptions</a></h3>
1.1 cvs 1914:
1.30 cvs 1915: <p>The behavior of the Thot editor and the actions that it performs are
1.1 cvs 1916: determined by the structure schemas. These actions are applied to all
1917: document and object types in accordance with their generic structure. For
1918: certain object types, such as tables and graphics, these actions are not
1919: sufficient or are poorly adapted and some special actions must be added to or
1920: substituted for certain standard actions. These special actions are called
1.18 cvs 1921: <em>exceptions</em>.</p>
1.30 cvs 1922:
1923: <p>Exceptions only inhibit or modify certain standard actions, but they can be
1.18 cvs 1924: used freely in every structure schema.</p>
1.30 cvs 1925:
1926: <p>Each structure schema can contain a section defining exceptions. It begins
1.18 cvs 1927: with the keyword <tt>EXCEPT</tt> and is composed of a sequence of exception
1.1 cvs 1928: declarations, separated by semicolons. Each declaration of an exception
1929: begins with the name of an element type or attribute followed by a colon. This
1930: indicates the element type or attribute to which the following exceptions
1.18 cvs 1931: apply. When the given element type name is a <a href="#sectd3285">mark
1932: pair</a>, and only in this case, the type name can be preceded by the keyword
1933: <tt>First</tt> or <tt>Second</tt>, to indicate if the exceptions which follow
1.1 cvs 1934: are associated with the first mark of the pair or the second. In the absence
1.18 cvs 1935: of this keyword, the first mark is used.</p>
1.30 cvs 1936:
1937: <p>When placed in an <a href="#sectc322">extension schema</a>, the keyword
1.18 cvs 1938: <tt>EXTERN</tt> indicates that the type name which follows is found in the
1.1 cvs 1939: principal schema (the schema being extended by the extension schema). The
1.18 cvs 1940: exceptions are indicated by a name. They are separated by semicolons.</p>
1941: <pre> [ 'EXCEPT' ExceptSeq ]
1.1 cvs 1942:
1.30 cvs 1943: ExceptSeq = Except ';' < Except ';' > .
1.1 cvs 1944: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr
1945: ':' ExcValSeq .
1946: ExcTypeOrAttr = ElemID / AttrID .
1.30 cvs 1947: ExcValSeq = ExcValue < ',' ExcValue > .
1.19 cvs 1948: ExcValue ='NoCut' / 'NoCreate' / 'NoHMove' /
1949: 'NoVMove' / 'NoHResize' / 'NoVResize' /
1950: 'NoMove' / 'NoResize' / 'MoveResize' /
1951: 'NewWidth' / 'NewHeight' / 'NewHPos' /
1952: 'NewVPos' / 'Invisible' /
1.28 cvs 1953: 'NoSelect' / 'NoSpellCheck' /
1.1 cvs 1954: 'Hidden' / 'ActiveRef' /
1955: 'ImportLine' / 'ImportParagraph' /
1956: 'NoPaginate' / 'ParagraphBreak' /
1.19 cvs 1957: 'PageBreak' / 'PageBreakAllowed' / 'PageBreakPlace' /
1958: 'PageBreakRepetition' / 'PageBreakRepBefore' /
1.9 cvs 1959: 'HighlightChildren' / 'ExtendedSelection' /
1.29 cvs 1960: 'ReturnCreateNL' / 'ReturnCreateWithin' /
1961: 'IsDraw' / 'IsTable' /
1.19 cvs 1962: 'IsRow' / 'IsColHead' / 'IsCell' /
1963: 'NewPercentWidth' / 'ColRef' / 'ColSpan' /
1964: 'RowSpan' / 'SaveDocument' / 'Shadow' .</pre>
1.30 cvs 1965:
1966: <p>The following are the available exceptions:</p>
1.18 cvs 1967: <dl>
1.30 cvs 1968: <dt><tt>NoCut</tt></dt>
1969: <dd>This exception can only be applied to element types. Elements of a
1970: type to which this exception is applied cannot be deleted by the
1971: editor.</dd>
1972: <dt><tt>NoCreate</tt></dt>
1973: <dd>This exception can only be applied to element types. Elements of a
1974: type to which this exception is applied cannot be created by ordinary
1975: commands for creating new elements. These elements are usually created
1976: by special actions associated with other exceptions.</dd>
1977: <dt><tt>NoHMove</tt></dt>
1978: <dd>This exception can only be applied to element types. Elements of a
1979: type to which this exception is applied cannot be moved horizontally
1980: with the mouse. Their children elements cannot be moved either.</dd>
1981: <dt><tt>NoVMove</tt></dt>
1982: <dd>This exception can only be applied to element types. Elements of a
1983: type to which this exception is applied cannot be moved vertically with
1984: the mouse. Their children elements cannot be moved either.</dd>
1985: <dt><tt>NoMove</tt></dt>
1986: <dd>This exception can only be applied to element types. Elements of a
1987: type to which this exception is applied cannot be moved in any direction
1988: with the mouse. Their children elements cannot be moved either.</dd>
1989: <dt><tt>NoHResize</tt></dt>
1990: <dd>This exception can only be applied to element types. Elements of a
1991: type to which this exception is applied cannot be resized horizontally
1992: with the mouse. Their children elements cannot be resized either.</dd>
1993: <dt><tt>NoVResize</tt></dt>
1994: <dd>This exception can only be applied to element types. Elements of a
1995: type to which this exception is applied cannot be resized vertically
1996: with the mouse. Their children elements cannot be resized either.</dd>
1997: <dt><tt>NoResize</tt></dt>
1998: <dd>This exception can only be applied to element types. Elements of a
1999: type to which this exception is applied cannot be resized in any
2000: direction with the mouse. Their children elements cannot be resized
2001: either.</dd>
2002: <dt><tt>MoveResize</tt></dt>
2003: <dd>This exception can only be applied to element types. Elements of a
2004: type to which this exception is applied can be moved and resized in any
2005: direction with the mouse, even if one of their ancestor element has an
2006: exception that prevents moving or resizing. Their children elements can
2007: also be resized or moved.</dd>
2008: <dt><tt>NewWidth</tt></dt>
2009: <dd>This exception can only be applied to numeric attributes. If the
2010: width of an element which has this attribute is modified with the mouse,
2011: the value of the new width will be assigned to the attribute.</dd>
2012: <dt><tt>NewHeight</tt></dt>
2013: <dd>This exception can only be applied to numeric attributes. If the
2014: height of an element which has this attribute is modified with the
2015: mouse, the value of the new height will be assigned to the
2016: attribute.</dd>
2017: <dt><tt>NewHPos</tt></dt>
2018: <dd>This exception can only be applied to numeric attributes. If the
2019: horizontal position of an element which has this attribute is modified
2020: with the mouse, the value of the new horizontal position will be
2021: assigned to the attribute.</dd>
2022: <dt><tt>NewVPos</tt></dt>
2023: <dd>This exception can only be applied to numeric attributes. If the
2024: vertical position of an element which has this attribute is modified
2025: with the mouse, the value of the new vertical position will be assigned
2026: to the attribute.</dd>
2027: <dt><tt>Invisible</tt></dt>
2028: <dd>This exception can only be applied to attributes, but can be applied
2029: to all attribute types. It indicates that the attribute must not be
2030: seen by the user and that its value must not be changed directly. This
2031: exception is usually used when another exception manipulates the value
2032: of an attribute.</dd>
2033: <dt><tt>NoSelect</tt></dt>
2034: <dd>This exception can only be applied to element types. Elements of a
2035: type to which this exception is applied cannot be selected directly
2036: with the mouse, but they can be selected by other methods provided by
2037: the editor.</dd>
2038: <dt>NoSpellCheck</dt>
2039: <dd>This exception can only be applied to element types. Elements of a
2040: type to which this exception is applied are not taken into account by
2041: the spell checker.</dd>
2042: <dt><tt>Hidden</tt></dt>
2043: <dd>This exception can only be applied to element types. It indicates
2044: that elements of this type, although present in the document's
2045: structure, must not be shown to the user of the editor. In particular,
2046: the creation menus must not propose this type and the selection message
2047: must not pick it.</dd>
2048: <dt><tt>ActiveRef</tt></dt>
2049: <dd>This exception can only be applied to attributes of the reference
2050: type. It indicates that when the user of the editor makes a double
2051: click on an element which possesses a reference attribute having this
2052: exception, the element designated by the reference attribute will be
2053: selected.</dd>
2054: <dt><tt>ImportLine</tt></dt>
2055: <dd>This exception can only be applied to element types. It indicates
2056: that elements of this type should receive the content of imported text
2057: files. An element is created for each line of the imported file. A
2058: structure schema cannot contain several exceptions <tt>ImportLine</tt>
2059: and, if it contains one, it should not contain any exception
2060: <tt>ImportParagraph</tt>.</dd>
2061: <dt><tt>ImportParagraph</tt></dt>
2062: <dd>This exception can only be applied to element types. It indicates
2063: that elements of this type should receive the content of imported text
1.31 cvs 2064: files. An element is created for each paragraph of the imported file. A
2065: paragraph is a sequence of lines without any empty line. A structure
1.30 cvs 2066: schema cannot contain several exceptions <tt>ImportParagraph</tt> and,
2067: if it contains one, it should not contain any exception
2068: <tt>ImportLine</tt>.</dd>
2069: <dt><tt>NoPaginate</tt></dt>
2070: <dd>This exception can only be applied to the root element, i.e. the name
2071: that appear after the keyword <tt>STRUCTURE</tt> at the beginning of the
2072: structure schema. It indicates that the editor should not allow the
2073: user to paginate documents of that type.</dd>
2074: <dt><tt>ParagraphBreak</tt></dt>
2075: <dd>This exception can only be applied to element types. When the caret
2076: is within an element of a type to which this exception is applied, it is
2077: that element that will be split when the user hits the Return key.</dd>
2078: <dt><tt>ReturnCreateNL</tt></dt>
2079: <dd>This exception can only be applied to element types. When the caret
2080: is within an element of a type to which this exception is applied, the
2081: Return key simply inserts a New line character (code \212) at the
2082: current position. The Return key does not create a new element; it does
2083: not split the current element either.</dd>
2084: <dt><tt>ReturnCreateWithin</tt></dt>
2085: <dd>This exception can only be applied to element types. When the caret
2086: is within an element of a type to which this exception is applied, the
2087: Return key will create a new element within that element, not a sibling
2088: after that element.</dd>
2089: <dt><tt>HighlightChildren</tt></dt>
2090: <dd>This exception can only be applied to element types. Elements of a
2091: type to which this exception is applied are not highlighted themselves
1.32 ! cvs 2092: when they are selected in the main view, but all their children are
! 2093: highlighted instead. If children have this exception too, the process is
! 2094: applied recursively. Only the main view defined in the presentation
! 2095: schema is concerned. Tee exception is ignored for other views.</dd>
1.30 cvs 2096: <dt><tt>ExtendedSelection</tt></dt>
2097: <dd>This exception can only be applied to element types. The selection
2098: extension command (middle button of the mouse) only add the clicked
2099: element (if it has that exception) to the current selection, without
2100: selecting other elements between the current selection and the clicked
2101: element.</dd>
2102: <dt>IsDraw, IsTable, IsColHead, IsRow, IsCell</dt>
2103: <dd>These exceptions can only be applied to element types. Elements of a
2104: type to which these exceptions are applied are identified as Draws,
2105: Tables, Colheads, Rows or Cells and specific processing are applied to
2106: them.</dd>
2107: <dt>ColRef</dt>
2108: <dd>This exception can only be applied to attributes of the reference
2109: type. It indicates that this attribute refers to the column head (see
2110: exception IsColHead) which the element belongs to.</dd>
2111: <dt>ColSpan, RowSpan</dt>
1.31 cvs 2112: <dd>These exceptions can only be applied to numeric attributes of cells.
1.30 cvs 2113: They indicate that attribute values give how many columns or rows the
2114: element spans.</dd>
2115: <dt>Shadow</dt>
2116: <dd>This exception can only be applied to element types. Text of elements
2117: of a type to which this exception is applied are displayed and printed
2118: as a set of stars ('*').</dd>
1.18 cvs 2119: </dl>
1.30 cvs 2120:
1.18 cvs 2121: <blockquote class="example">
1.30 cvs 2122: <p><strong>Example:</strong></p>
2123:
2124: <p>Consider a structure schema for object-style graphics which defines the
2125: Graphic_object element type with the associated Height and Weight numeric
2126: attributes. Suppose that we want documents of this class to have the
2127: following qualities:</p>
2128: <ul>
2129: <li>Whenever the width or height of an object is changed using the mouse,
2130: the new values are stored in the object's Width and Height
2131: attributes.</li>
2132: <li>The user should not be able to change the values of the Width and
2133: Height attributes via the Attributes menu of the Thot editor.</li>
2134: </ul>
2135:
2136: <p>The following exceptions will produce this effect.</p>
2137: <pre>STRUCT
1.1 cvs 2138: ...
1.5 cvs 2139: Graphics_object (ATTR Height = Integer; Width = Integer)
1.1 cvs 2140: = GRAPHICS with Height ?= 10, Width ?= 10;
2141: ...
2142: EXCEPT
2143: Height: NewHeight, Invisible;
1.18 cvs 2144: Width: NewWidth, Invisible;</pre>
2145: </blockquote>
2146: </div>
2147: </div>
1.1 cvs 2148:
1.18 cvs 2149: <div class="section">
1.30 cvs 2150: <h2><a name="sectb33">Some examples</a></h2>
1.1 cvs 2151:
1.30 cvs 2152: <p>In order to illustrate the principles of the document model and the syntax
2153: of the S language, this section presents two examples of structure schemas.
2154: One defines a class of documents, the other defines a class of objects.</p>
1.1 cvs 2155:
1.18 cvs 2156: <div class="subsection">
1.30 cvs 2157: <h3><a name="sectc331">A class of documents: articles</a></h3>
1.1 cvs 2158:
1.30 cvs 2159: <p>This example shows a possible structure for articles published in a
2160: journal. Text between braces is comments.</p>
1.18 cvs 2161: <pre>STRUCTURE Article; { This schema defines the Article class }
1.1 cvs 2162: DEFPRES ArticleP; { The default presentation schema is
2163: ArticleP }
2164: ATTR { Global attribute definitions }
2165: WordType = Definition, IndexWord, DocumentTitle;
2166: { A single global attribute is defined, with three values }
2167: STRUCT { Definition of the generic structure }
2168: Article = BEGIN { The Article class has an aggregate
2169: structure }
2170: Title = BEGIN { The title is an aggregate }
2171: French_title =
2172: Text WITH Language='Fran\347ais';
2173: English_title =
2174: Text WITH Language='English';
2175: END;
2176: Authors =
2177: LIST OF (Author
2178: (ATTR Author_type=principal,secondary)
2179: { The Author type has a local attribute }
2180: = BEGIN
2181: Author_name = Text;
2182: Info = Paragraphs ;
2183: { Paragraphs is defined later }
2184: Address = Text;
2185: END
2186: );
2187: Keywords = Text;
2188: { The journal's editor introduces the article
2189: with a short introduction, in French and
2190: in English }
2191: Introduction =
2192: BEGIN
2193: French_intr = Paragraphs WITH
2194: Language='Fran\347ais';
2195: English_intr = Paragraphs WITH
2196: Language='English';
2197: END;
2198: Body = Sections; { Sections are defined later }
2199: { Appendixes are only created on demand }
2200: ? Appendices =
2201: LIST OF (Appendix =
2202: BEGIN
2203: Appendix_Title = Text;
2204: Appendix_Contents = Paragraphs;
2205: END
2206: );
2207: END; { End of the Article aggregate }
2208:
2209: Sections = LIST [2..*] OF (
2210: Section = { At least 2 sections }
2211: BEGIN
2212: Section_title = Text;
2213: Section_contents =
2214: BEGIN
2215: Paragraphs;
2216: Sections; { Sections at a lower level }
2217: END;
2218: END
2219: );
2220:
2221: Paragraphs = LIST OF (Paragraph = CASE OF
2222: Enumeration =
2223: LIST [2..*] OF
2224: (Item = Paragraphs);
2225: Isolated_formula = Formula;
2226: LIST OF (UNIT);
2227: END
2228: );
2229:
2230: ASSOC { Associated elements definitions }
2231:
2232: Figure = BEGIN
1.5 cvs 2233: Figure_caption = Text;
1.1 cvs 2234: Illustration = NATURE;
2235: END;
2236:
2237: Biblio_citation = CASE OF
2238: Ref_Article =
2239: BEGIN
2240: Authors_Bib = Text;
2241: Article_Title = Text;
2242: Journal = Text;
2243: Page_Numbers = Text;
2244: Date = Text;
2245: END;
2246: Ref_Livre =
2247: BEGIN
2248: Authors_Bib; { Defined above }
2249: Book_Title = Text;
2250: Editor = Text;
2251: Date; { Defined above }
2252: END;
2253: END;
2254:
2255: Note = Paragraphs - (Ref_note);
2256:
2257: UNITS { Elements which can be used in objects }
2258:
2259: Ref_note = REFERENCE (Note);
2260: Ref_biblio = REFERENCE (Biblio_citation);
2261: Ref_figure = REFERENCE (Figure);
2262: Ref_formula = REFERENCE (Isolated_formula);
2263:
2264: EXPORT { Skeleton elements }
2265:
2266: Title,
1.5 cvs 2267: Figure with Figure_caption,
1.1 cvs 2268: Section With Section_title;
2269:
1.18 cvs 2270: END { End of the structure schema }</pre>
1.30 cvs 2271:
2272: <p>This schema is very complete since it defines both paragraphs and
1.1 cvs 2273: bibliographic citations. These element types could just as well be defined in
1.18 cvs 2274: other structure schemas, as is the case with the <tt>Formula</tt> class. All
1.1 cvs 2275: sorts of other elements can be inserted into an article, since a paragraph can
2276: contain any type of unit. Similarly, figures can be any class of document or
1.18 cvs 2277: object that the user chooses.</p>
1.30 cvs 2278:
2279: <p>Generally, an article doesn't contain appendices, but it is possible to add
1.1 cvs 2280: them on explicit request: this is the effect of the question mark before the
1.18 cvs 2281: word Appendices.</p>
1.30 cvs 2282:
2283: <p>The Figure, Biblio_citation and Note elements are associated elements.
2284: Thus, they are only used in <tt>REFERENCE</tt> statements.</p>
2285:
2286: <p>Various types of cross-references can be put in paragraphs. They can also
2287: be placed the objects which are part of the article, since the
2288: cross-references are defined as units (<tt>UNITS</tt>).</p>
2289:
2290: <p>There is a single restriction to prevent the creation of Ref_note elements
1.18 cvs 2291: within notes.</p>
1.30 cvs 2292:
2293: <p>It is worth noting that the S language permits the definition of recursive
1.1 cvs 2294: structures like sections: a section can contain other sections (which are thus
2295: at the next lower level of the document tree). Paragraphs are also recursive
2296: elements, since a paragraph can contain an enumeration in which each element
1.18 cvs 2297: (<tt>Item</tt>) is composed of paragraphs.</p>
2298: </div>
1.1 cvs 2299:
1.18 cvs 2300: <div class="subsection">
1.30 cvs 2301: <h3><a name="sectc332">A class of objects: mathematical formulas</a></h3>
1.1 cvs 2302:
1.30 cvs 2303: <p>The example below defines the <tt>Formula</tt> class which is used in
2304: Article documents. This class represents mathematical formulas with a rather
2305: simple structure, but sufficient to produce a correct rendition on the screen
2306: or printer. To support more elaborate operations (formal or numeric
1.1 cvs 2307: calculations), a finer structure should be defined. This class doesn't use any
1.18 cvs 2308: other class and doesn't define any associated elements or units.</p>
2309: <pre>STRUCTURE Formula;
1.1 cvs 2310: DEFPRES FormulaP;
2311:
2312: ATTR
2313: String_type = Function_name, Variable_name;
2314:
2315: STRUCT
2316: Formula = Expression;
2317: Expression = LIST OF (Construction);
2318: Construction = CASE OF
2319: TEXT; { Simple character string }
2320: Index = Expression;
2321: Exponent = Expression;
2322: Fraction =
2323: BEGIN
1.6 cvs 2324: Numerator = Expression;
1.1 cvs 2325: Denominator = Expression;
2326: END;
2327: Root =
2328: BEGIN
2329: ? Order = TEXT;
2330: Root_Contents = Expression;
2331: END;
2332: Integral =
2333: BEGIN
2334: Integration_Symbol = SYMBOL;
2335: Lower_Bound = Expression;
2336: Upper_Bound = Expression;
2337: END;
2338: Triple =
2339: BEGIN
2340: Princ_Expression = Expression;
2341: Lower_Expression = Expression;
2342: Upper_Expression = Expression;
2343: END;
2344: Column = LIST [2..*] OF
2345: (Element = Expression);
2346: Parentheses_Block =
2347: BEGIN
2348: Opening = SYMBOL;
2349: Contents = Expression;
2350: Closing = SYMBOL;
2351: END;
2352: END; { End of Choice Constructor }
1.18 cvs 2353: END { End of Structure Schema }</pre>
1.30 cvs 2354:
2355: <p>This schema defines a single global attribute which allows functions and
1.1 cvs 2356: variables to be distinguished. In the presentation schema, this attribute can
2357: be used to choose between roman (for functions) and italic characters (for
1.18 cvs 2358: variables).</p>
1.30 cvs 2359:
2360: <p>A formula's structure is that of a mathematical expression, which is itself
2361: a sequence of mathematical constructions. A mathematical construction can be
1.1 cvs 2362: either a simple character string, an index, an exponent, a fraction, a root,
2363: etc. Each of these mathematical constructions has a sensible structure which
2364: generally includes one or more expressions, thus making the formula class's
1.18 cvs 2365: structure definition recursive.</p>
1.30 cvs 2366:
2367: <p>In most cases, the roots which appear in the formulas are square roots and
1.1 cvs 2368: their order (2) is not specified. This is why the Order component is marked
2369: optional by a question mark. When explicitly requested, it is possible to add
1.18 cvs 2370: an order to a root, for example for cube roots (order = 3).</p>
1.30 cvs 2371:
2372: <p>An integral is formed by an integration symbol, chosen by the user (simple
1.1 cvs 2373: integral, double, curvilinear, etc.), and two bounds. A more fine-grained
2374: schema would add components for the integrand and the integration variable.
2375: Similarly, the Block_Parentheses construction leaves the choice of opening and
2376: closing symbols to the user. They can be brackets, braces, parentheses,
1.18 cvs 2377: etc.</p>
2378: </div>
2379: </div>
2380: <hr>
2381: </div>
1.1 cvs 2382:
1.18 cvs 2383: <div class="chapter">
2384: <h1><a name="sect4">The P Language</a></h1>
1.1 cvs 2385:
1.18 cvs 2386: <div class="section">
1.30 cvs 2387: <h2><a name="sectb41">Document presentation</a></h2>
1.1 cvs 2388:
1.30 cvs 2389: <p>Because of the model adopted for Thot, the presentation of documents is
1.1 cvs 2390: clearly separated from their structure and content. After having presented
2391: the logical structure of documents, we now detail the principles implemented
1.18 cvs 2392: for their presentation. The concept of <em>presentation</em> encompasses what
1.5 cvs 2393: is often called the page layout, the composition, or the document style. It
1.18 cvs 2394: is the set of operations which display the document on the screen or print it
2395: on paper. Like logical structure, document presentation is defined
2396: generically with the help of a language, called P.</p>
1.1 cvs 2397:
1.18 cvs 2398: <div class="subsection">
1.30 cvs 2399: <h3><a name="sectc411">Two levels of presentation</a></h3>
1.1 cvs 2400:
1.30 cvs 2401: <p>The link between structure and presentation is clear: the logical
2402: organization of a document is used to carry out its presentation, since the
2403: purpose of the presentation is to make evident the organization of the
2404: document. But the presentation is equally dependent on the device used to
2405: render the document. Certain presentation effects, notably changes of font or
2406: character set, cannot be performed on all printers or on all screens. This is
2407: why Thot uses a two-level approach, where the presentation is first described
2408: in abstract terms, without taking into account each particular device, and
2409: then the presentation is realized within the constraints of a given
2410: device.</p>
2411:
2412: <p>Thus, presentation is only described as a function of the structure of the
1.1 cvs 2413: documents and the image that would be produced on an idealized device. For
2414: this reason, presentation descriptions do not refer to any device
1.18 cvs 2415: characteristics: they describe <em>abstract presentations</em> which can be
2416: concretized on different devices.</p>
1.30 cvs 2417:
2418: <p>A presentation description also defines a <em>generic presentation</em>,
2419: since it describes the appearance of a class of documents or objects. This
2420: generic presentation must also be applied to document and object instances,
2421: each conforming to its generic logical structure, but with all the allowances
2422: that were called to mind above: missing elements, constructed elements with
2423: other logical structures, etc.</p>
2424:
2425: <p>In order to preserve the homogeneity between documents and objects,
1.1 cvs 2426: presentation is described with a single set of tools which support the layout
2427: of a large document as well as the composition of objects like a graphical
2428: figure or mathematical formula. This unity of presentation description tools
2429: contrasts with the traditional approach, which focuses more on documents than
2430: objects and thus is based on the usual typographic conventions, such as the
2431: placement of margins, indentations, vertical spaces, line lengths,
1.18 cvs 2432: justification, font changes, etc.</p>
2433: </div>
1.1 cvs 2434:
1.18 cvs 2435: <div class="subsection">
1.30 cvs 2436: <h3><a name="sectc412">Boxes</a></h3>
1.1 cvs 2437:
1.30 cvs 2438: <p>To assure the homogeneity of tools, all presentation in Thot, for documents
2439: as well as for the objects which they contain, is based on the notion of the
1.18 cvs 2440: <em>box</em>, such as was implemented in T<sub><big>E</big></sub>X.</p>
1.30 cvs 2441:
2442: <p>Corresponding to each element of the document is a box, which is the
1.1 cvs 2443: rectangle enclosing the element on the display device (screen or sheet of
1.18 cvs 2444: paper); the outline of this rectangle is not visible, except when a <a
2445: href="#sectc4230a"><tt>ShowBox</tt> rule</a> applies to the element. The sides
2446: of the box are parallel to the sides of the screen or the sheet of paper. By
2447: way of example, a box is associated with a character string, a line of text, a
2448: page, a paragraph, a title, a mathematical formula, or a table cell.</p>
1.30 cvs 2449:
2450: <p>Whatever element it corresponds to, each box possesses four sides and four
1.18 cvs 2451: axes, which we designate as follows (<a href="#boxes">see figure</a>):</p>
2452: <dl>
1.30 cvs 2453: <dt><tt>Top</tt></dt>
2454: <dd>the upper side,</dd>
2455: <dt><tt>Bottom</tt></dt>
2456: <dd>the lower side,</dd>
2457: <dt><tt>Left</tt></dt>
2458: <dd>the left side,</dd>
2459: <dt><tt>Right</tt></dt>
2460: <dd>the right side,</dd>
2461: <dt><tt>VMiddle</tt></dt>
2462: <dd>the vertical axis passing through the center of the box,</dd>
2463: <dt><tt>HMiddle</tt></dt>
2464: <dd>the horizontal axis passing through the center of the box,</dd>
2465: <dt><tt>VRef</tt></dt>
2466: <dd>the vertical reference axis,</dd>
2467: <dt><tt>HRef</tt></dt>
2468: <dd>the horizontal reference axis.</dd>
1.18 cvs 2469: </dl>
2470:
2471: <div class="figure">
2472: <hr>
2473: <pre> Left VRef VMiddle Right
1.1 cvs 2474: : :
2475: Top -----------------------------
2476: | : : |
2477: | : : |
2478: | : : |
2479: | : : |
2480: | : : |
2481: HMiddle ..|...........................|..
2482: | : : |
2483: | : : |
2484: HRef ..|...........................|..
2485: | : : |
2486: | : : |
2487: Bottom -----------------------------
1.18 cvs 2488: : :</pre>
1.30 cvs 2489:
2490: <p align="center"><em><a name="boxes">The sides and axes of
2491: boxes</a><em></em></em></p>
1.18 cvs 2492: <hr>
1.30 cvs 2493: </div>
1.19 cvs 2494:
1.30 cvs 2495: <p>The principal role of boxes is to set the extent and position of the images
2496: of the different elements of a document with respect to each other on the
1.1 cvs 2497: reproduction device. This is done by defining relations between the boxes of
2498: different elements which give relative extents and positions to these
1.18 cvs 2499: boxes.</p>
1.30 cvs 2500:
2501: <p>There are three types of boxes:</p>
1.18 cvs 2502: <ul>
1.30 cvs 2503: <li>boxes corresponding to structural elements of the document,</li>
2504: <li>presentation boxes,</li>
2505: <li>page layout boxes.</li>
1.18 cvs 2506: </ul>
1.30 cvs 2507:
2508: <p><strong>Boxes corresponding to structural elements of the document</strong>
1.1 cvs 2509: are those which linked to each of the elements (base or structured) of the
2510: logical structure of the document. Such a box contains all the contents of
1.18 cvs 2511: the element to which it corresponds (there is an exception: see <a
2512: href="#sectc4220">rules <tt>VertOverflow</tt> and <tt>HorizOverflow</tt></a>).
2513: These boxes form a tree-like structure, identical to that of the structural
2514: elements to which they correspond. This tree expresses the inclusion
2515: relationships between the boxes: a box includes all the boxes of its subtree.
2516: On the other hand, there are no predefined rules for the relative positions of
2517: the included boxes. If they are at the same level, they can overlap, be
2518: contiguous, or be disjoint. The rules expressed in the generic presentation
2519: specify their relative positions.</p>
1.30 cvs 2520:
2521: <p><strong>Presentation boxes</strong> represent elements which are not found
2522: in the logical structure of the document but which are added to meet the needs
2523: of presentation. These boxes are linked to the elements of the logical
2524: structure that are best suited to bringing them out. For example, they are
2525: used to add the character string ``Summary:'' before the summary in the
2526: presentation of a report or to represent the fraction bar in a formula, or
2527: also to make the title of a field in a form appear. These elements have no
2528: role in the logical structure of the document: the presence of a Summary
2529: element in the document does not require the creation of another structural
2530: object to hold the word ``Summary''. Similarly, if a Fraction element contains
2531: both a Numerator element and a Denominator element, the fraction bar has no
2532: purpose structurally. On the other hand, these elements of the presentation
2533: are important for the reader of the reproduced document or for the user of an
1.1 cvs 2534: editor. This is why they must appear in the document's image. It is the
2535: generic presentation which specifies the presentation boxes to add by
2536: indicating their content (a base element for which the value is specified) and
2537: the position that they must take in the tree of boxes. During editing, these
1.18 cvs 2538: boxes cannot be modified by the user.</p>
1.30 cvs 2539:
2540: <p><strong>Page layout boxes</strong> are boxes created implicitly by the page
1.1 cvs 2541: layout rules. These rules indicate how the contents of a structured element
2542: must be broken into lines and pages. In contrast to presentation boxes, these
2543: line and page boxes do not depend on the logical structure of the document,
1.18 cvs 2544: but rather on the physical constraints of the output devices: character size,
2545: height and width of the window on the screen or of the sheet of paper.</p>
2546: </div>
1.1 cvs 2547:
1.18 cvs 2548: <div class="subsection">
1.30 cvs 2549: <h3><a name="sectc413">Views and visibility</a></h3>
1.1 cvs 2550:
1.30 cvs 2551: <p>One of the operations that one might wish to perform on a document is to
2552: view it is different ways. For this reason, it is possible to define several
1.18 cvs 2553: <em>views</em> for the same document, or better yet, for all documents of the
1.1 cvs 2554: same class. A view is not a different presentation of the document, but
2555: rather a filter which only allows the display of certain parts of the
2556: document. For example, it might be desirable to see only the titles of
2557: chapters and sections in order to be able to move rapidly through the
2558: document. Such a view could be called a ``table of contents''. It might also
2559: be desirable to see only the mathematical formulas of a document in order to
2560: avoid being distracted by the non-mathematical aspects of the document. A
1.18 cvs 2561: ``mathematics'' view could provide this service.</p>
1.30 cvs 2562:
2563: <p>Views, like presentation, are based on the generic logical structure. Each
1.1 cvs 2564: document class, and each generic presentation, can be provided with views
2565: which are particularly useful for that class or presentation. For each view,
1.18 cvs 2566: the <em>visibility</em> of elements is defined, indicated whether or not the
1.1 cvs 2567: elements must be presented to the user. The visibility is calculated as a
2568: function of the type of the elements or their hierarchical position in the
2569: structure of the document. Thus, for a table of contents, all the ``Chapter
2570: Title'' and ``Section Title'' elements are made visible. However, the
2571: hierarchical level could be used to make the section titles invisible below a
2572: certain threshold level. By varying this threshold, the granularity of the
2573: view can be varied. In the ``mathematics'' view, only Formula elements would
1.18 cvs 2574: be made visible, no matter what their hierarchical level.</p>
1.30 cvs 2575:
2576: <p>Because views are especially useful for producing a synthetic image of the
1.1 cvs 2577: document, it is necessary to adapt the presentation of the elements to the
2578: view in which they appear. For example, it is inappropriate to have a page
2579: break before every chapter title in the table of contents. Thus, generic
2580: presentations take into account the possible views and permit each element
1.18 cvs 2581: type's presentation to vary according the view in which its image appears.</p>
1.30 cvs 2582:
2583: <p><a name="views">Views</a> are also used, when editing documents, to display
1.1 cvs 2584: the associated elements. So, in addition to the primary view of the document,
2585: there can be a ``notes'' view and a ``figures'' view which contain,
2586: respectively, the associated elements of the Note and Figure types. In this
2587: way, it is possible to see simultaneously the text which refers to these
2588: elements and the elements themselves, even if they will be separated when
1.18 cvs 2589: printed.</p>
2590: </div>
1.1 cvs 2591:
1.18 cvs 2592: <div class="subsection">
1.30 cvs 2593: <h3><a name="sectc414">Pages</a></h3>
1.1 cvs 2594:
1.30 cvs 2595: <p>Presentation schemas can be defined which display the document as a long
1.1 cvs 2596: scroll, without page breaks. This type of schema is particularly well-suited
2597: to the initial phase of work on a document, where jumps from page to page
2598: would hinder composing and reading the document on a screen. In this case,
2599: the associated elements (such as notes), which are normally displayed in the
2600: page footer, are presented in a separate window. But, once the document is
2601: written, it may be desirable to display the document on the screen in the same
2602: manner in which it will be printed. So, the presentation schema must define
1.18 cvs 2603: pages.</p>
1.30 cvs 2604:
2605: <p>The P language permits the specification of the dimensions of pages as well
2606: as their composition. It is possible to generate running titles, page
2607: numbers, zones at the bottom of the page for notes, etc. The editor follows
2608: this model and inserts page break marks in the document which are used during
2609: printing, insuring that the pages on paper are the same as on the screen.</p>
2610:
2611: <p>Once a document has been edited with a presentation schema defining pages,
2612: it contains page marks. But it is always possible to edit the document using
2613: a schema without pages. In this case, the page marks are simply ignored by
2614: the editor. They are considered again as soon as a schema with pages is used.
1.18 cvs 2615: Thus, the user is free to choose between schemas with and without pages.</p>
1.30 cvs 2616:
2617: <p>Thot treats the page break, rather than the page itself, as a box. This
2618: page break box contains all the elements of one page's footer, a rule marking
2619: the edge of this page, and all the elements of the next page's header. The
1.1 cvs 2620: elements of the header and footer can be running titles, page number,
2621: associated elements (notes, for example), etc. All these elements, as well as
2622: their content and graphical appearance, are defined by the generic
1.18 cvs 2623: presentation.</p>
2624: </div>
1.1 cvs 2625:
1.18 cvs 2626: <div class="subsection">
1.30 cvs 2627: <h3><a name="sectc415">Numbering</a></h3>
1.1 cvs 2628:
1.30 cvs 2629: <p>Many elements are numbered in documents: pages, chapters, sections,
2630: formulas, theorems, notes, figures, bibliographic references, exercises,
2631: examples, lemmas, etc. Because Thot has a notion of logical structure, all of
2632: these numbers (with the exception of pages) are redundant with information
2633: implicit in the logical structure of the document. Such numbers are simply a
2634: way to make the structure of the document more visible. So, they are part of
2635: the document's presentation and are calculated by the editor from the logical
1.1 cvs 2636: structure. The structure does not contain numbers as such; it only defines
2637: relative structural positions between elements, which serve as ordering
1.18 cvs 2638: relations on these elements.</p>
1.30 cvs 2639:
2640: <p>If the structure schema defines the body of a document as a sequence of at
1.18 cvs 2641: least two chapters:</p>
2642: <pre>Body = LIST [2..*] OF Chapter;</pre>
1.30 cvs 2643:
2644: <p>the sequence defined by the list constructor is ordered and each chapter
2645: can be assigned a number based on its rank in the Body list. Therefore, all
1.18 cvs 2646: elements contained in lists a the structure of a document can be numbered, but
2647: they are not the only ones. The tree structure induced by the aggregate,
2648: list, and choice constructors (excluding references) defines a total order on
2649: the elements of the document's primary structure. So, it is possible to
2650: define a numbering which uses this order, filtering elements according to
2651: their type so that only certain element types are taken into account in the
2652: numbering. In this way, it possible to number all the theorems and lemmas of
2653: a chapter in the same sequence of numbers, even when they are not part of the
2654: same list constructor and appear at different levels of the document's tree.
2655: By changing the filter, they can be numbered separately: one sequence of
2656: numbers for theorems, another for the lemmas.</p>
1.30 cvs 2657:
2658: <p>Associated elements pose a special problem, since they are not part of the
1.1 cvs 2659: document's primary structure, but are attached only by references, which
2660: violate the total order of the document. Then, these associated elements are
2661: frequently numbered, precisely because the number is an effective way to
2662: visualize the reference. In order to resolve this problem, Thot implicitly
2663: defines a list constructor for each type of associated element, gathering
2664: together (and ordering) these elements. Thus, the associated elements can be
1.18 cvs 2665: numbered by type.</p>
1.30 cvs 2666:
2667: <p>Since they are calculated from the document's logical structure and only
2668: for the needs of the presentation, numbers are presentation elements,
2669: described by presentation boxes, just like the fraction bar or the word
2670: ``Summary''. Nevertheless, numbers differ from these other boxes because their
2671: content varies from instance to instance, even though they are of the same
2672: type, whereas all fraction bars are horizontal lines and the same word
2673: ``Summary'' appears at the head of every document's summary.</p>
1.18 cvs 2674: </div>
1.1 cvs 2675:
1.18 cvs 2676: <div class="subsection">
1.30 cvs 2677: <h3><a name="sectc416">Presentation parameters</a></h3>
1.1 cvs 2678:
1.30 cvs 2679: <p>The principal parameters which determine document presentation are the
1.18 cvs 2680: <em>positions</em> and <em>dimensions</em> of boxes, the <em>font</em>, the
2681: <em>style</em>, the <em>size</em>, the <em>underlining</em> and the
2682: <em>color</em> of their content. From these parameters, and some others of
1.1 cvs 2683: less importance, it is possible to represent the usual typographic parameters
2684: for the textual parts of the document. These same parameters can be used to
2685: describe the geometry of the non-textual elements, even though they are
1.18 cvs 2686: two-dimensional elements unlike the text, which is linear.</p>
1.30 cvs 2687:
2688: <p>As we have already seen, the positions of the boxes always respect the
2689: rule of enclosure: a box in the tree encloses all the boxes of the next lower
2690: level which are attached to it. The positional parameters permit the
2691: specification of the position of each box in relation to the enclosing box or
2692: to its sibling boxes (boxes directly attached to the same enclosing box in the
2693: tree of boxes).</p>
2694:
2695: <p>The presentation parameters also provide control over the dimensions of the
1.1 cvs 2696: boxes. The dimensions of a box can depend either on its content or on its
2697: context (its sibling boxes and the enclosing box). Each dimension (height or
1.18 cvs 2698: width) can be defined independently of the other.</p>
1.30 cvs 2699:
2700: <p>Because of the position and dimension parameters, it is possible to do the
1.1 cvs 2701: same things that are normally done in typography by changing margins, line
2702: lengths, and vertical or horizontal skips. This approach can also align or
1.18 cvs 2703: center elements and groups of elements.</p>
1.30 cvs 2704:
2705: <p>In contrast to the position and dimension parameters, the font, style,
2706: size, underlining, and color do not concern the box itself (the rectangle
2707: delimiting the element), but its content. These parameters indicate the
2708: typographic attributes which must be applied to the text contained in the box,
2709: and by extension, to all base elements.</p>
2710:
2711: <p>For text, the font parameter is used to change the family of characters
1.1 cvs 2712: (Times, Helvetica, Courier, etc.); the style is used to obtain italic or
2713: roman, bold or light characters; the size determines the point size of the
2714: characters; underlining defines the type and thickness of the lines drawn
1.18 cvs 2715: above, below, or through the characters.</p>
1.30 cvs 2716:
2717: <p>For graphics, the line style parameter can be either solid, dotted, or
2718: dashed; the line thickness parameter controls the width of the lines; the fill
2719: pattern parameter determines how closed geometric figures must be filled.</p>
2720:
2721: <p>While some of the parameters which determine the appearance of a box's
1.1 cvs 2722: contents make sense only for one content type (text or graphic), other
2723: parameters apply to all content types: these are the color parameters. These
1.18 cvs 2724: indicate the color of lines and the background color.</p>
2725: </div>
2726: </div>
1.1 cvs 2727:
1.18 cvs 2728: <div class="section">
1.30 cvs 2729: <h2><a name="sectb42">Presentation description language</a></h2>
2730:
2731: <p>A generic presentation defines the values of presentation parameters (or
2732: the way to calculate those values) for a generic structure, or more precisely,
2733: for all the element types and all the global and local attributes defined in
2734: that generic structure. This definition of the presentation parameters is
2735: made with the P language. A program written in this language, that is a
2736: generic presentation expressed in P, is call a <em>presentation schema</em>.
2737: This section describes the syntax and semantics of the language, using the
2738: same <a href="#sectc321">meta-language</a> as was used for the definition of
2739: the S language.</p>
1.1 cvs 2740:
1.30 cvs 2741: <p>Recall that it is possible to write many different presentation schemas for
1.1 cvs 2742: the same class of documents or objects. This allows users to choose for a
2743: document the graphical appearance which best suits their type of work or
1.18 cvs 2744: their personal taste.</p>
1.1 cvs 2745:
1.18 cvs 2746: <div class="subsection">
1.30 cvs 2747: <h3><a name="sectc421">The organization of a presentation schema</a></h3>
1.1 cvs 2748:
1.30 cvs 2749: <p>A presentation schema begins with the word <tt>PRESENTATION</tt> and ends
2750: with the word <tt>END</tt>. The word <tt>PRESENTATION</tt> is followed by the
2751: name of the generic structure to which the presentation will be applied. This
2752: name must be the same as that which follows the keyword <tt>STRUCTURE</tt> in
2753: the structure schema associated with the presentation schema.</p>
2754:
2755: <p>After this declaration of the name of the structure, the following sections
1.18 cvs 2756: appear (in order):</p>
2757: <ul>
1.30 cvs 2758: <li>Declarations of
2759: <ul>
2760: <li>all views,</li>
2761: <li>printed views,</li>
2762: <li>counters,</li>
2763: <li>presentation constants,</li>
2764: <li>variables,</li>
2765: </ul>
2766: </li>
2767: <li>default presentation rules,</li>
2768: <li>presentation box and page layout box definitions,</li>
2769: <li>presentation rules for structured elements,</li>
2770: <li>presentation rules for attributes,</li>
2771: <li>rules for transmitting values to attributes of included documents.</li>
1.18 cvs 2772: </ul>
1.30 cvs 2773:
2774: <p>Each of these sections is introduced by a keyword which is followed by a
1.18 cvs 2775: sequence of declarations. Every section is optional.</p>
2776: <pre> SchemaPres ='PRESENTATION' ElemID ';'
1.1 cvs 2777: [ 'VIEWS' ViewSeq ]
2778: [ 'PRINT' PrintViewSeq ]
2779: [ 'COUNTERS' CounterSeq ]
2780: [ 'CONST' ConstSeq ]
2781: [ 'VAR' VarSeq ]
2782: [ 'DEFAULT' ViewRuleSeq ]
2783: [ 'BOXES' BoxSeq ]
2784: [ 'RULES' PresentSeq ]
2785: [ 'ATTRIBUTES' PresAttrSeq ]
2786: [ 'TRANSMIT' TransmitSeq ]
2787: 'END' .
1.18 cvs 2788: ElemID = NAME .</pre>
2789: </div>
1.1 cvs 2790:
1.18 cvs 2791: <div class="subsection">
1.30 cvs 2792: <h3><a name="sectc422">Views</a></h3>
1.1 cvs 2793:
1.30 cvs 2794: <p>Each of the possible views must be declared in the presentation schema. As
1.18 cvs 2795: has <a href="#views">already been described</a>, the presentation rules for an
1.1 cvs 2796: element type can vary according to the view in which the element appears. The
2797: name of the view is used to designate the view to which the presentation rules
1.18 cvs 2798: apply (see the <a href="#inkeyword"><tt>IN</tt> instruction</a>). The
1.1 cvs 2799: definition of the view's contents are dispersed throughout the presentation
2800: rules attached to the different element types and attributes. The
1.18 cvs 2801: <tt>VIEWS</tt> section is simply a sequence of view names separated by commas
2802: and terminated by a semi-colon.</p>
1.30 cvs 2803:
2804: <p>One of the view names (and only one) can be followed by the keyword
1.18 cvs 2805: <tt>EXPORT</tt>. This keyword identifies the view which presents the members
2806: of the document class in <a href="#sectc3213">skeleton form</a>. The
2807: graphical appearance and the content of this view is defined just as with
2808: other views, but it is useless to specify presentation rules concerning this
2809: view for the elements which are not loaded in the skeleton form.</p>
1.30 cvs 2810:
2811: <p>It is not necessary to declare any views; in this case there is a single
1.1 cvs 2812: unnamed view. If many views are declared, the first view listed is considered
2813: the principal view. The principal view is the one to which all rules that are
1.18 cvs 2814: not preceded by an indication of a view will apply (see the <a
2815: href="#inkeyword">instruction <tt>IN</tt></a>).</p>
1.30 cvs 2816:
2817: <p>The principal view is the the one which the editor presents on the screen
2818: when the user asks to create or edit a document. Thus, it makes sense to put
2819: the most frequently used view at the head of the list. But if the structure
1.18 cvs 2820: schema contains <a href="#sectc3213">skeleton elements</a> and is loaded in
2821: its skeleton form, the view whose name is followed by the keyword
2822: <tt>EXPORT</tt> will be opened and no other views can be opened.</p>
2823: <pre> 'VIEWS' ViewSeq
1.1 cvs 2824: ViewSeq = ViewDeclaration
1.30 cvs 2825: < ',' ViewDeclaration > ';' .
1.1 cvs 2826: ViewDeclaration = ViewID [ 'EXPORT' ] .
1.18 cvs 2827: ViewID = NAME .</pre>
1.30 cvs 2828:
1.18 cvs 2829: <blockquote class="example">
1.30 cvs 2830: <p><strong>Example:</strong></p>
2831:
2832: <p>When editing a report, it might be useful have views of the table of
2833: contents and of the mathematical formulas, in addition to the principal view
2834: which shows the document in its entirety. To achieve this, a presentation
2835: schema for the Report class would have the following <tt>VIEWS</tt>
2836: section:</p>
2837: <pre>VIEWS
1.18 cvs 2838: Full_text, Table_of_contents, Formulas;</pre>
1.30 cvs 2839:
2840: <p>The contents of these views are specified in the presentation rules of
2841: the schema.</p>
1.18 cvs 2842: </blockquote>
2843: </div>
1.1 cvs 2844:
1.18 cvs 2845: <div class="subsection">
1.30 cvs 2846: <h3><a name="sectc423">Print Views</a></h3>
1.1 cvs 2847:
1.30 cvs 2848: <p>When editing a document, each view is presented in a different window. In
1.18 cvs 2849: addition to the views specified by the <tt>VIEWS</tt> instruction, the user
1.1 cvs 2850: can display the associated elements with one window for each type of
1.18 cvs 2851: associated element.</p>
1.30 cvs 2852:
2853: <p>When printing a document, it is possible to print any number of views,
2854: chosen from among all the views which the editor can display (views in the
2855: strict sense or associated elements). Print views, as well as the order in
2856: which they must be printed, are indicated by the <tt>PRINT</tt> instruction.
2857: It appears after the <tt>VIEWS</tt> instruction and is formed of the keyword
1.18 cvs 2858: <tt>PRINT</tt> followed by the ordered list of print view names. The print
1.1 cvs 2859: view names are separated by commas and followed by a semi-colon. A print view
1.18 cvs 2860: name is either a view name declared in the <tt>VIEWS</tt> instruction or the
1.1 cvs 2861: name of an associated element type (with an ``s'' added to the end). The
1.18 cvs 2862: associated element must have been declared in the <tt>ASSOC</tt> section of
2863: the structure schema.</p>
2864: <pre> 'PRINT' PrintViewSeq
1.30 cvs 2865: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.18 cvs 2866: PrintView = ViewID / ElemID .</pre>
1.30 cvs 2867:
2868: <p>If the <tt>PRINT</tt> instruction is absent, the printing program will
2869: print only the principal view (the first view specified by the <tt>VIEWS</tt>
1.18 cvs 2870: instruction or the single, unnamed view when there is no <tt>VIEWS</tt>
2871: instruction).</p>
1.30 cvs 2872:
1.18 cvs 2873: <blockquote class="example">
1.30 cvs 2874: <p><strong>Example:</strong></p>
2875:
2876: <p>Consider a Report presentation using the view declarations from the
2877: preceding example. Suppose we want to print the full text and table of
2878: contents views, but not the Formulas view, which is only useful when
2879: editing. In addition, suppose that we also want to print the bibliographic
2880: citations, which are associated elements (of type <tt>Citation</tt>). A
2881: sensible printing order would be to print the full text then the
2882: bibliography and finally the table of contents. To obtain this result when
2883: printing, the presentation schema would say:</p>
2884: <pre>PRINT
1.18 cvs 2885: Full_text, Citations, Table_of_contents;</pre>
2886: </blockquote>
2887: </div>
2888:
2889: <div class="subsection">
1.30 cvs 2890: <h3><a name="sectc424">Counters</a></h3>
1.18 cvs 2891:
1.30 cvs 2892: <p>A presentation has a <em>counter</em> for each type of number in the
1.1 cvs 2893: presentation. All counters, and therefore all types of numbers, used in the
1.18 cvs 2894: schema must be declared after the <tt>COUNTERS</tt> keyword.</p>
1.30 cvs 2895:
2896: <p>Each counter declaration is composed of a name identifying the counter
1.1 cvs 2897: followed by a colon and the counting function to be applied to the counter.
1.18 cvs 2898: The counter declaration ends with a semi-colon.</p>
1.30 cvs 2899:
2900: <p>The counting function indicates how the counter values will be calculated.
1.16 cvs 2901: Three types of counting functions are available. The first type is used to
2902: count the elements of a list or aggregate: it assigns to the counter the rank
1.18 cvs 2903: of the element in the list or aggregate. More precisely, the function</p>
2904: <pre>RANK OF ElemID [ LevelAsc ] [ INIT AttrID ]
2905: [ 'REINIT' AttrID ]</pre>
1.30 cvs 2906:
2907: <p>indicates that when an element creates, by a creation rule (see the <a
1.18 cvs 2908: href="#sectc4232"><tt>Create</tt> instructions</a>), a presentation box
1.5 cvs 2909: containing the counter value, this value is the rank of the creating element,
1.18 cvs 2910: if it is of type <tt>ElemID</tt>, otherwise the rank of the first element of
2911: type <tt>ElemID</tt> which encloses the creating element in the logical
2912: structure of the document.</p>
1.30 cvs 2913:
2914: <p>The type name can be preceded by a star in the special case where the
1.18 cvs 2915: structure schema defines an element of whose <tt>ElemID</tt> is the same as
2916: that of an <a href="#sectd3284">inclusion</a> without expansion or with
2917: partial expansion. To resolve this ambiguity, the <tt>ElemID</tt> alone
2918: refers to the type defined in the structure schema while the <tt>ElemID</tt>
2919: preceded by a star refers to the included type.</p>
1.30 cvs 2920:
2921: <p>The type name <tt>ElemID</tt> can be followed by an integer. That number
1.1 cvs 2922: represents the relative level, among the ancestors of the creating element, of
1.18 cvs 2923: the element whose rank is asked. If that relative level <i>n</i> is unsigned,
2924: the <i>n</i><sup>th</sup> element of type <tt>ElemID</tt> encountered when
1.1 cvs 2925: travelling the logical structure from the root to the creating element is
1.16 cvs 2926: taken into account. If the relative level is negative, the logical structure
2927: is travelled in the other direction, from the creating element to the
1.18 cvs 2928: root.</p>
1.30 cvs 2929:
2930: <p>The function can end with the keyword <tt>INIT</tt> followed by the name of
2931: a numeric attribute (and only a numeric attribute). Then, the rank of the
2932: first element of the list or aggregate is considered to be the value of this
1.1 cvs 2933: attribute, rather than the default value of 1, and the rank of the other
2934: elements is shifted accordingly. The attribute which determines the initial
1.18 cvs 2935: value is searched on the element itself and on its ancestors.</p>
1.30 cvs 2936:
2937: <p>The function can end with the keyword <tt>REINIT</tt> followed by the name
2938: of a numeric attribute (and only a numeric attribute). Then, if an element to
2939: be counted has this attribute, the counter value for this element is the
1.1 cvs 2940: attribute value and the following elements are numbered starting from this
1.18 cvs 2941: value.</p>
1.30 cvs 2942:
2943: <p>When the <tt>RANK</tt> function is written</p>
1.18 cvs 2944: <pre>RANK OF Page [ ViewID ] [ INIT AttrID ]</pre>
1.30 cvs 2945:
2946: <p>(<tt>Page</tt>is a keyword of the P language), the counter takes as its
2947: value the number of the page on which the element which creates the
2948: presentation box containing the number appears. This is done as if the pages
2949: of the document form a list for each view. The counter only takes into
2950: account the pages of the relevant view, that is the view displaying the
2951: presentation box whose contents take the value of the number. However, if the
2952: keyword <tt>Page</tt> is followed by the name of a view (between parentheses),
2953: it is the pages of that view that are taken into account. As in the preceding
2954: form, the <tt>RANK</tt> function applied to pages can end with the
2955: <tt>INIT</tt> keyword followed by the name of a numeric attribute which sets
2956: the value of the first page's number. This attribute must be a local
2957: attribute of the document itself, and not of one of its components.</p>
2958:
2959: <p>The second counting function is used to count the occurrences of a certain
1.18 cvs 2960: element type in a specified context. The instruction</p>
2961: <pre>SET n ON Type1 ADD m ON Type2 [ INIT AttrID ]</pre>
1.30 cvs 2962:
2963: <p>says that when the document is traversed from beginning to end (in the
2964: order induced by the logical structure), the counter is assigned the value
1.18 cvs 2965: <tt>n</tt> each time an element of type <tt>Type1</tt> is encountered, no
2966: matter what the current value of the counter, and the value <tt>m</tt> is
2967: added to the current value of the counter each time an element of type
2968: <tt>Type2</tt> is encountered.</p>
1.30 cvs 2969:
2970: <p>As with the <tt>RANK</tt> function, the type names can be preceded by a
2971: star to resolve the ambiguity of included elements.</p>
2972:
2973: <p>If the function ends with the keyword <tt>INIT</tt> followed by the name of
2974: an attribute and if the document possesses this attribute, the value of this
1.18 cvs 2975: attribute is used in place of <tt>n</tt>. The attribute must be numeric. It
2976: is searched on the element itself and on its ancestors.</p>
1.30 cvs 2977:
2978: <p>This function can also be used with the <tt>Page</tt> keyword in the place
2979: of <tt>Type1</tt> or <tt>Type2</tt>. In the first case, the counter is
1.18 cvs 2980: reinitialized on each page with the value <tt>n</tt>, while in the second
2981: case, it is incremented by <tt>m</tt> on each page. As with the preceding
2982: counting function, the word <tt>Page</tt> can be followed by a name between
1.1 cvs 2983: parentheses. In this case, the name specifies a view whose pages are taken
1.18 cvs 2984: into account.</p>
1.30 cvs 2985:
2986: <p>The definition of a counter can contain several <tt>SET</tt> functions and
1.18 cvs 2987: several <tt>ADD</tt> functions, each with a different value. The total number
2988: of counting functions must not be greater than 6.</p>
1.30 cvs 2989:
2990: <p>The third counting function is used to count the elements of a certain type
1.16 cvs 2991: encountered when travelling from the creating element to the root of the
2992: logical structure. The creating element is included if it is of that type.
1.18 cvs 2993: That function is written</p>
2994: <pre>RLEVEL OF Type</pre>
1.30 cvs 2995:
2996: <p>where <tt>Type</tt> represents the type of the elements to be counted.</p>
2997:
2998: <p>The formal definition of counter declarations is:</p>
1.18 cvs 2999: <pre> 'COUNTERS' CounterSeq
1.30 cvs 3000: CounterSeq = Counter < Counter > .
1.1 cvs 3001: Counter = CounterID ':' CounterFunc ';' .
3002: CounterID = NAME .
3003: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
1.16 cvs 3004: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.30 cvs 3005: SetFunction < SetFunction >
3006: AddFunction < AddFunction >
1.16 cvs 3007: [ 'INIT' AttrID ] /
3008: 'RLEVEL' 'OF' ElemID .
1.1 cvs 3009: SLevelAsc = [ '-' ] LevelAsc .
3010: LevelAsc = NUMBER .
3011: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
3012: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
3013: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 3014: [ '*' ] ElemID .
1.18 cvs 3015: CounterValue = NUMBER .</pre>
1.30 cvs 3016:
1.18 cvs 3017: <blockquote class="example">
1.30 cvs 3018: <p><strong>Example:</strong></p>
3019:
3020: <p>If the body of a chapter is defined as a sequence of sections in the
3021: structure schema:</p>
3022: <pre>Chapter_body = LIST OF (Section =
1.1 cvs 3023: BEGIN
3024: Section_Title = Text;
3025: Section_Body = Paragraphs;
3026: END
1.18 cvs 3027: );</pre>
1.30 cvs 3028:
3029: <p>the section counter is declared:</p>
3030: <pre>SectionCtr : RANK OF Section;</pre>
3031:
3032: <p>and the display of the section number before the section title is
3033: obtained by a <a href="#sectc4232"><tt>CreateBefore</tt> rule</a> attached
3034: the <tt>Section_Title</tt> type, which creates a presentation box whose
3035: content is the value of the <tt>SectionCtr</tt> counter (see the <a
3036: href="#sectc4231"><tt>Content</tt> instruction</a>).</p>
3037:
3038: <p>In order to number the formulas separately within each chapter, the
3039: formula counter is declared:</p>
3040: <pre>FormulaCtr : SET 0 ON Chapter ADD 1 ON Formula;</pre>
3041:
3042: <p>and the display of the formula number in the right margin, alongside each
3043: formula, is obtained by a <tt>CreateAfter</tt> instruction attached to the
3044: <tt>Formula</tt> type, which creates a presentation box whose content is the
3045: value of the <tt>FormulaCtr</tt> counter.</p>
3046:
3047: <p>To number the page chapter by chapter, with the first page of each
3048: chapter having the number 1, the counter definition would be</p>
3049: <pre>ChapterPageCtr : SET 0 ON Chapter ADD 1 ON Page;</pre>
3050:
3051: <p>If there is also a chapter counter</p>
3052: <pre>ChapterCtr : RANK OF Chapter;</pre>
3053:
3054: <p>the <a href="#sectc4231">content</a> of a presentation box created at the
3055: top of each page could be defined as:</p>
3056: <pre>Content : (VALUE(ChapterCtr, URoman) TEXT '-'
1.18 cvs 3057: VALUE(ChapterPageCtr, Arabic));</pre>
1.30 cvs 3058:
3059: <p>Thus, the presentation box contains the number of the chapter in
3060: upper-case roman numerals followed by a hyphen and the number of the page
3061: within the chapter in arabic numerals.</p>
1.18 cvs 3062: </blockquote>
1.30 cvs 3063:
1.18 cvs 3064: <blockquote class="example">
1.30 cvs 3065: <p><strong>Example:</strong></p>
3066:
3067: <p>To count tables and figures together in a document of the chapter type, a
3068: counter could be defined using:</p>
3069: <pre>CommonCtr : SET 0 ON Chapter ADD 1 ON Table
1.18 cvs 3070: ADD 1 ON Figure;</pre>
3071: </blockquote>
3072: </div>
1.1 cvs 3073:
1.18 cvs 3074: <div class="subsection">
1.30 cvs 3075: <h3><a name="sectc425">Presentation constants</a></h3>
1.1 cvs 3076:
1.30 cvs 3077: <p>Presentation constants are used in the definition of the content of
1.18 cvs 3078: presentation boxes. This content is used in <a href="#sectc426">variable
3079: definitions</a> and in the <a href="#sectc4231"><tt>Content</tt> rule</a>. The
1.1 cvs 3080: only presentation constants which can be used are character strings,
1.2 cvs 3081: mathematical symbols, graphical elements, and pictures, that is to say, base
1.18 cvs 3082: elements.</p>
1.30 cvs 3083:
3084: <p>Constants can be defined directly in the variables or presentation boxes
1.18 cvs 3085: (<tt>Content</tt> rule) which use them. But it is only necessary them to
1.1 cvs 3086: declare once, in the constant declaration section, even though they are used
3087: in many variables or boxes. Thus, each declared constant has a name, which
3088: allows it to be designated whenever it is used, a type (one of the four base
3089: types) and a value (a character string or a single character for mathematical
1.18 cvs 3090: symbols and graphical elements).</p>
1.30 cvs 3091:
3092: <p>The constant declarations appear after the keyword <tt>CONST</tt>. Each
1.1 cvs 3093: declaration is composed of the name of the constant, an equals sign, a keyword
1.18 cvs 3094: representing its type (<tt>Text</tt>, <tt>Symbol</tt>, <tt>Graphics</tt> or
3095: <tt>Picture</tt>) and the string representing its value. A semi-colon
3096: terminates each declaration.</p>
1.30 cvs 3097:
3098: <p>In the case of a character string, the keyword <tt>Text</tt> can be
3099: followed by the name of an alphabet (for example, <tt>Greek</tt> or
3100: <tt>Latin</tt>) in which the constant's text should be expressed. If the
3101: alphabet name is absent, the Latin alphabet is used. When the alphabet name
3102: is present, only the first letter of the alphabet name is interpreted. Thus,
3103: the words <tt>Greek</tt> and <tt>Grec</tt> designate the same alphabet. In
3104: current versions of Thot, only the Greek and Latin alphabets are
3105: available.</p>
1.18 cvs 3106: <pre> 'CONST' ConstSeq
1.30 cvs 3107: ConstSeq = Const < Const > .
1.1 cvs 3108: Const = ConstID '=' ConstType ConstValue ';' .
3109: ConstID = NAME .
3110: ConstType ='Text' [ Alphabet ] / 'Symbol' /
3111: 'Graphics' / 'Picture' .
3112: ConstValue = STRING .
1.18 cvs 3113: Alphabet = NAME .</pre>
1.30 cvs 3114:
3115: <p>For character strings in the Latin alphabet (ISO Latin-1 character set),
1.1 cvs 3116: characters having codes higher than 127 (decimal) are represented by their
1.18 cvs 3117: code in octal.</p>
1.30 cvs 3118:
3119: <p>In the case of a symbol or graphical element, the value only contains a
3120: single character, between apostrophes, which indicates the form of the element
3121: which must be drawn in the box whose content is the constant. The symbol or
1.1 cvs 3122: graphical element takes the dimensions of the box, which are determined by the
1.18 cvs 3123: <tt>Height</tt> and <tt>Width</tt> rules. See <a href="#sectb72">table of
3124: codes</a> for the symbols and graphical elements.</p>
1.30 cvs 3125:
1.18 cvs 3126: <blockquote class="example">
1.30 cvs 3127: <p><strong>Example:</strong></p>
3128:
3129: <p>The constants ``Summary:'' and fraction bar, which were described
3130: earlier, are declared:</p>
3131: <pre>CONST
1.1 cvs 3132: SummaryConst = Text 'Summary:';
1.18 cvs 3133: Bar = Graphics 'h';</pre>
3134: </blockquote>
3135: </div>
1.1 cvs 3136:
1.18 cvs 3137: <div class="subsection">
1.30 cvs 3138: <h3><a name="sectc426">Variables</a></h3>
1.1 cvs 3139:
1.30 cvs 3140: <p>Variables permit the definition of computed content for presentation boxes.
3141: A variable is associated with a presentation box by a <tt>Content</tt> rule;
3142: but before being used in a <tt>Content</tt> rule, a variable can be defined in
3143: the <tt>VAR</tt> section. It is also possible to define a variable at the
3144: time of its use in a <tt>Content</tt> rule, as can be done with a
3145: constant.</p>
3146:
3147: <p>A variable has a name and a value which is a character string resulting
3148: from the concatenation of the values of a sequence of functions. Each
3149: variable declaration is composed of the variable name followed by a colon and
3150: the sequence of functions which produces its value, separated by spaces. Each
1.18 cvs 3151: declaration is terminated by a semi-colon.</p>
3152: <pre> 'VAR' VarSeq
1.30 cvs 3153: VarSeq = Variable < Variable > .
1.1 cvs 3154: Variable = VarID ':' FunctionSeq ';' .
3155: VarID = NAME .
1.30 cvs 3156: FunctionSeq = Function < Function > .</pre>
3157:
3158: <p>Several functions are available. The first two return, in the form of a
1.18 cvs 3159: character string, the current date. <tt>DATE</tt> returns the date in
3160: English, while <tt>FDATE</tt> returns the date in french.</p>
1.30 cvs 3161:
3162: <p>Two other functions, <tt>DocName</tt> and <tt>DirName</tt>, return the
1.18 cvs 3163: document name and the directory where the document is stored.</p>
1.30 cvs 3164:
3165: <p>Function <tt>ElemName</tt> returns the type of the element which created
3166: the presentation box whose contents are the variable.</p>
3167:
3168: <p>Another function simply returns the value of a presentation constant. For
3169: any constant declared in the <tt>CONST</tt> section, it is sufficient to give
3170: the name of the constant. Otherwise, the type and value of the constant must
3171: be given, using the same form as in a <a href="#sectc425">constant
1.18 cvs 3172: declaration</a>. If the constant is not of type text, (types <tt>Symbol</tt>,
3173: <tt>Graphics</tt> or <tt>Picture</tt>), it must be alone in the variable
3174: definition; only constants of type <tt>Text</tt> can be mixed with other
3175: functions.</p>
1.30 cvs 3176:
3177: <p>It is also possible to obtain the value of an attribute, simply by
3178: mentioning the attribute's name. The value of this function is the value of
3179: the attribute for the element which created the presentation box whose
3180: contents are the variable. If the creating element does not have the
3181: indicated attribute, the value is an empty string. In the case of a numeric
3182: attribute, the attribute is translated into a decimal number in arabic
3183: numerals. If another form is desired, the <tt>VALUE</tt> function must be
3184: used.</p>
3185:
3186: <p>The last available function returns, as a character string, the value of a
1.1 cvs 3187: counter, an attribute or a page number. This value can be presented in
1.18 cvs 3188: different styles. The keyword <tt>VALUE</tt> is followed (between
1.1 cvs 3189: parentheses) by the name of the counter, the name of the attribute, or the
1.18 cvs 3190: keyword <tt>PageNumber</tt> and the desired style, the two parameters being
1.1 cvs 3191: separated by a comma. The style is a keyword which indicates whether the
1.18 cvs 3192: value should be presented in arabic numerals (<tt>Arabic</tt>), lower-case
3193: roman numerals (<tt>LRoman</tt>), or upper-case roman numerals
3194: (<tt>URoman</tt>), or by an upper-case letter (<tt>Uppercase</tt>) or
3195: lower-case letter (<tt>Lowercase</tt>).</p>
1.30 cvs 3196:
3197: <p>For a page counter, the keyword <tt>PageNumber</tt> can be followed,
3198: between parentheses, by the name of the view from which to obtain the page
3199: number. By default, the first view declared in the <tt>VIEWS</tt> section is
3200: used. The value obtained is the number of the page on which is found the
3201: element that is using the variable in a <tt>Content</tt> rule.</p>
3202:
3203: <p>For an ordinary counter, the name of the counter can be preceded by the
1.18 cvs 3204: keyword <tt>MaxRangeVal</tt> or <tt>MinRangeVal</tt>. These keywords mean
1.1 cvs 3205: that the value returned by the function is the maximum (minimum resp.) value
3206: taken by the counter in the whole document, not the value for the element
1.18 cvs 3207: concerned by the function.</p>
3208: <pre> Function = 'DATE' / 'FDATE' /
1.1 cvs 3209: 'DocName' / 'DirName' /
3210: 'ElemName' / 'AttributeName' /
3211: ConstID / ConstType ConstValue /
3212: AttrID /
3213: 'VALUE' '(' PageAttrCtr ','
3214: CounterStyle ')' .
1.6 cvs 3215: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
1.1 cvs 3216: [ MinMax ] CounterID / AttrID .
3217: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
3218: 'Uppercase' / 'Lowercase' .
1.18 cvs 3219: MinMax = 'MaxRangeVal' / 'MinRangeVal' .</pre>
1.30 cvs 3220:
1.18 cvs 3221: <blockquote class="example">
1.30 cvs 3222: <p><strong>Example:</strong></p>
3223:
3224: <p>To make today's date appear at the top of the first page of a report, a
3225: <a href="#sectc4232"><tt>CREATE</tt> rule</a> associated with the
3226: Report_Title element type generates a presentation box whose content
3227: (specified by the <tt>Content</tt> rule of that presentation box) is the
3228: variable:</p>
3229: <pre>VAR
1.18 cvs 3230: Todays_date : TEXT 'Version of ' DATE;</pre>
1.30 cvs 3231:
3232: <p>To produce, before each section title, the chapter number (in upper-case
3233: roman numerals) followed by the section number (in arabic numerals), two
3234: counters must be defined:</p>
3235: <pre>COUNTERS
1.1 cvs 3236: ChapterCtr : RANK OF Chapter;
1.18 cvs 3237: SectionCtr : RANK OF Section;</pre>
1.30 cvs 3238:
3239: <p>and the Section_Title element must create a presentation box whose
3240: content is the variable</p>
3241: <pre>VAR
1.1 cvs 3242: SectionNum : VALUE (ChapterCtr, URoman) TEXT '-'
1.18 cvs 3243: VALUE (SectionCtr, Arabic);</pre>
1.30 cvs 3244:
3245: <p>In order to make the page number on which each section begins appear in
3246: the table of contents view next to the section title, each Section_Title
3247: element must create a presentation box, visible only in the table of
3248: contents view, whose content is the variable:</p>
3249: <pre>VAR
1.1 cvs 3250: TitlePageNume :
1.18 cvs 3251: VALUE (PageNumber(Full_text), Arabic);</pre>
3252: </blockquote>
3253: </div>
1.1 cvs 3254:
1.18 cvs 3255: <div class="subsection">
1.30 cvs 3256: <h3><a name="sectc427">Default presentation rules</a></h3>
1.1 cvs 3257:
1.30 cvs 3258: <p>In order to avoid having to specify, for each element type defined in the
1.1 cvs 3259: structure schema, values for every one of the numerous presentation
3260: parameters, the presentation schema allows the definition of a set of default
3261: presentation rules. These rules apply to all the boxes of the elements
3262: defined in the structure schema and to the presentation boxes and page layout
3263: boxes defined in the presentation schema. Only rules which differ from these
1.18 cvs 3264: default need to be specified in other sections of the presentation schema.</p>
1.30 cvs 3265:
3266: <p>For the primary view, the default rules can define every presentation
1.18 cvs 3267: parameter, but not the <a href="#presfunct">presentation functions</a> or the
3268: <a href="#sectc4223">linebreaking conditions</a> (the <tt>NoBreak1</tt>,
3269: <tt>NoBreak2</tt>, and <tt>Gather</tt> rules).</p>
1.30 cvs 3270:
3271: <p>In a presentation schema, the default presentation rules section is
3272: optional; in this case, the <tt>DEFAULT</tt> keyword is also absent and the
3273: following rules are considered to be the default rules:</p>
1.26 cvs 3274: <pre> Visibility: Enclosing =;
3275: VertRef: * . Left;
3276: HorizRef: Enclosed . HRef;
3277: Height: Enclosed . Height;
3278: Width: Enclosed . Width;
3279: VertPos: Top = Previous . Bottom;
3280: HorizPos: Left = Enclosing . Left;
3281: MarginTop: 0;
3282: MarginRight: 0;
3283: MarginBottom: 0;
3284: MarginLeft: 0;
3285: PaddingTop: 0;
3286: PaddingRight: 0;
3287: PaddingBottom: 0;
3288: PaddingLeft: 0;
3289: BorderTopWidth: 0;
3290: BorderRightWidth: 0;
3291: BorderBottomWidth: 0;
3292: BorderLeftWidth: 0;
3293: BorderTopColor: Foreground;
3294: BorderRightColor: Foreground;
3295: BorderBottomColor: Foreground;
3296: BorderLeftColor: Foreground;
3297: BorderTopStyle: None;
3298: BorderRightStyle: None;
3299: BorderBottomStyle: None;
3300: BorderLeftStyle: None;
3301: VertOverflow: No;
3302: HorizOverflow: No;
3303: Size: Enclosing =;
3304: Style: Enclosing =;
3305: Weight: Enclosing =;
3306: Font: Enclosing =;
3307: Underline: Enclosing =;
3308: Thickness: Enclosing =;
3309: Indent: Enclosing =;
3310: LineSpacing: Enclosing =;
3311: Adjust: Enclosing =;
3312: Justify: Enclosing =;
3313: Hyphenate: Enclosing =;
3314: PageBreak: Yes;
3315: LineBreak: Yes;
3316: InLine: Yes;
3317: Depth: 0;
3318: LineStyle: Enclosing =;
3319: LineWeight: Enclosing =;
3320: FillPattern: Enclosing =;
3321: Background: Enclosing =;
3322: Foreground: Enclosing =;</pre>
1.30 cvs 3323:
3324: <p>If other values are desired for the default rules, they must be defined
1.1 cvs 3325: explicitly in the default rules section. In fact, it is only necessary to
3326: define those default rules which differ from the ones above, since the rules
1.18 cvs 3327: above will be used whenever a rule is not explicitly named.</p>
1.30 cvs 3328:
3329: <p>Default rules for views other than the primary view can also be specified.
1.1 cvs 3330: Otherwise, the default rules for the primary views are applied to the other
1.18 cvs 3331: views.</p>
1.30 cvs 3332:
3333: <p>Default rules are expressed in the same way as <a
3334: href="#sectc4215">explicit rules for document elements</a>.</p>
1.18 cvs 3335: </div>
1.1 cvs 3336:
1.18 cvs 3337: <div class="subsection">
1.30 cvs 3338: <h3><a name="sectc428">Presentation and page layout boxes</a></h3>
1.1 cvs 3339:
1.30 cvs 3340: <p>The presentation process uses elements which are not part of the logical
1.1 cvs 3341: structure of the document, such as pages (which are the page layout boxes) or
3342: alternatively, rules, numbers, or words introducing certain parts of the
3343: document, such as ``Summary'', ``Appendices'', ``Bibliography'', etc. (which
1.18 cvs 3344: are presentation boxes).</p>
1.30 cvs 3345:
3346: <p>After the word <tt>BOXES</tt>, each presentation or page layout box is
3347: defined by its name and a sequence of presentation rules which indicate how
3348: they must be displayed. These rules are the same as those which define the
3349: boxes associated with element of the logical structure of the document, with a
1.18 cvs 3350: single exception, the <a href="#sectc4231"><tt>Content</tt> rule</a> which is
1.1 cvs 3351: used only to specify the content of presentation boxes. The content of boxes
3352: associated with elements of the document structure is defined in each document
3353: or object and thus is not specified in the presentation schema, which applies
1.18 cvs 3354: to all documents or objects of a class.</p>
1.30 cvs 3355:
3356: <p>Among the rules which define a presentation box, certain ones can refer to
1.1 cvs 3357: another presentation box (for example, in their positional rules). If the
3358: designated box is defined after the box which designates it, a
1.18 cvs 3359: <tt>FORWARD</tt> instruction followed by the name of the designated box must
3360: appear before the designation.</p>
3361: <pre> 'BOXES' BoxSeq
1.30 cvs 3362: BoxSeq = Box < Box > .
1.1 cvs 3363: Box ='FORWARD' BoxID ';' /
3364: BoxID ':' ViewRuleSeq .
1.18 cvs 3365: BoxID = NAME .</pre>
3366: </div>
1.1 cvs 3367:
1.18 cvs 3368: <div class="subsection">
1.30 cvs 3369: <h3><a name="sectc429">Presentation of structured elements</a></h3>
1.1 cvs 3370:
1.30 cvs 3371: <p>After the words <tt>RULES</tt>, the presentation schema gives the
3372: presentation rules that apply to the elements whose types are defined in the
3373: structure schema. Only those rules which differ from the <a
1.18 cvs 3374: href="#sectc427">default</a> must be specified in the <tt>RULES</tt>
3375: section.</p>
1.30 cvs 3376:
3377: <p>The rule definitions for each element type are composed of the name of the
1.1 cvs 3378: element type (as specified in the structure schema) followed by a colon and
1.18 cvs 3379: the set of rules specific to that type.</p>
1.30 cvs 3380:
3381: <p>The type name can be preceded by a star in the special case where the
1.18 cvs 3382: structure schema defines an <a href="#sectd3284">inclusion</a> without
1.1 cvs 3383: expansion (or with partial expansion) of a type with the same name as an
1.18 cvs 3384: element of defined in the structure schema.</p>
1.30 cvs 3385:
3386: <p>In the case where the element is a <a href="#sectd3285">mark pair</a>, but
1.18 cvs 3387: only in this case, the type name can be preceded by the keywords
3388: <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
3389: that follow apply to the first or second mark of the pair.</p>
3390: <pre> 'RULES' PresentSeq
1.30 cvs 3391: PresentSeq = Present < Present > .
1.6 cvs 3392: Present = [ '*' ] [ FirstSec ] ElemID ':'
3393: ViewRuleSeq .
1.18 cvs 3394: FirstSec = 'First' / 'Second' .</pre>
1.30 cvs 3395:
3396: <p>A presentation schema can define presentation rules for base elements,
3397: which are defined implicitly in the structure schemas. In the English version
3398: of the presentation schema compiler, the base type names are the same as in
3399: the S language, but they are terminated by the <tt>_UNIT</tt> suffix:
1.18 cvs 3400: <tt>TEXT_UNIT</tt>, <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>,
3401: <tt>GRAPHICS_UNIT</tt>. The base type names are written in upper-case
3402: letters.</p>
3403: </div>
3404:
3405: <div class="subsection">
1.30 cvs 3406: <h3><a name="sectc4210">Logical attribute presentation</a></h3>
1.18 cvs 3407:
1.30 cvs 3408: <p>After the keyword <tt>ATTRIBUTES</tt>, all attributes which are to have
3409: some effect on the presentation of the element to which they are attached must
3410: be mentioned, along with the corresponding presentation rules. This is true
3411: for both global attributes (which can be attached to all element types) and
3412: local attributes (which can only be attached to certain element types).</p>
3413:
3414: <p>Also mentioned in this section are attributes which imply an effect on
1.1 cvs 3415: elements in the subtree of the element to which they are attached. The
3416: presentation of these descendants can be modified as a function of the value
3417: of the attribute which they inherit, just as if it was attached to them
1.18 cvs 3418: directly.</p>
1.30 cvs 3419:
3420: <p>The specification for each attribute includes the attribute's name,
3421: followed by an optional value specification and, after a colon, a set of
3422: rules. The set of rules must contain at least one rule.</p>
3423:
3424: <p>When there is no value specification, the rules are applied to all elements
1.1 cvs 3425: which carry the attribute, no matter what their value. When the rules must
3426: only apply when the attribute has certain values, these values must be
1.18 cvs 3427: specified. Thus, the same attribute can appear in the <tt>ATTRIBUTES</tt>
1.1 cvs 3428: section several times, with each appearance having a different value
3429: specification. However, reference attributes never have a value specification
1.18 cvs 3430: and, as a result, can only appear once in the <tt>ATTRIBUTES</tt> section.</p>
1.30 cvs 3431:
3432: <p>To specify that the presentation rules apply to some of the descendants of
3433: the element having the attribute, the name of the affected element type is
3434: given, between parentheses, after the attribute name. This way, the
3435: presentation rules for the attribute will be applied to the element having the
3436: attribute, if it is of the given type, and to all of its descendants of the
3437: given type. In the case where this type is a <a href="#sectd3285">mark
3438: pair</a>, but only in this case, the type name can be preceded by the keywords
3439: <tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
3440: that follow apply to the first or second mark of the pair. If the rule must
3441: apply to several different element types, the specification must be repeated
3442: for each element type.</p>
3443:
3444: <p>The specification of values for which the presentation rules will be
3445: applied varies according to the type of the attribute:</p>
1.18 cvs 3446: <dl>
1.30 cvs 3447: <dt>numeric attribute</dt>
3448: <dd>If the rules are to apply for one value of the attribute, then the
3449: attribute name is followed by an equals sign and this value. If the
3450: rules are to apply for all values less than (or greater than) a
3451: threshold value, non-inclusive, the attribute name followed by a '<'
3452: sign (or a '>' sign, respectively) and the threshold value. If the
3453: rules must apply to a range of values, the attribute name is followed by
3454: the word '<tt>IN</tt>' and the two bounds of the range, enclosed in
3455: brackets and separated by two periods ('<tt>..</tt>'). In the case of
3456: ranges, the values of the bounds are included in the range.
3457: <p>The threshold value in the comparisons can be the value of an
3458: attribute attached to an ancestor element. In this case, the attribute
3459: name is given instead of a constant value.</p>
3460: <p>It is also possible to write rules which apply only when a comparison
3461: between two different attributes of the element's ancestors is true. In
3462: this case, the first attribute name is followed by a comparison keyword
3463: and the name of the second attribute. The comparison keywords are
3464: <tt>EQUAL</tt> (simple equality), <tt>LESS</tt> (non-inclusive less
3465: than), and <tt>GREATER</tt> (non-inclusive greater than).</p>
3466: </dd>
3467: <dt>text attribute</dt>
3468: <dd>If the rules are to apply for one value of the attribute, then the
3469: attribute name is followed by an equals sign and this value.</dd>
3470: <dt>reference attribute</dt>
3471: <dd>There is never a value specification; the rules apply no matter what
3472: element is designated by the attribute.</dd>
3473: <dt>enumerated attribute</dt>
3474: <dd>If the rules are to apply for one value of the attribute, then the
3475: attribute name is followed by an equals sign and this value.</dd>
1.18 cvs 3476: </dl>
1.30 cvs 3477:
3478: <p>The order in which the rules associated with a numeric attribute are
3479: defined is important. When multiple sets of rules can be applied, the first
3480: set declared is the one used.</p>
3481:
3482: <p>Rules for attributes have priority over both default rules and rules
1.1 cvs 3483: associated with element types. The attribute rules apply to the element to
3484: which the attribute is attached. It is the rules which apply to the
3485: surrounding elements (and especially to the descendants) which determine the
3486: effect of the attribute rules on the environment ( and especially on the
1.18 cvs 3487: terminal elements of the structure).</p>
3488: <pre> 'ATTRIBUTES' PresAttrSeq
1.30 cvs 3489: PresAttrSeq = PresAttr < PresAttr > .
1.1 cvs 3490: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
3491: [ AttrRelation ] ':' ViewRuleSeq .
3492: AttrID = NAME .
3493: AttrRelation ='=' AttrVal /
1.30 cvs 3494: '>' [ '-' ] MinValue /
1.1 cvs 3495: '<' [ '-' ] MaxValue /
3496: 'IN' '[' [ '-' ] LowerBound '..'
3497: [ '-' ] UpperBound ']' /
3498: 'GREATER' AttrID /
3499: 'EQUAL' AttrID /
3500: 'LESS' AttrID .
3501: AttrVal = [ '-' ] EqualNum / EqualText /
3502: AttrValue .
3503: MinValue = NUMBER .
3504: MaxValue = NUMBER .
3505: LowerBound = NUMBER .
3506: UpperBound = NUMBER.
3507: EqualNum = NUMBER .
3508: EqualText = STRING .
1.18 cvs 3509: AttrValue = NAME .</pre>
1.30 cvs 3510:
3511: <p>In presentation rules associated with a numeric attribute (and only in such
1.1 cvs 3512: rules), the attribute name can be used in place of a numeric value. In this
3513: case, the value of the attribute is used in the application of the rule. Thus,
3514: the attribute can represent a relation between the size of two boxes, the
3515: height and width of a box, the height of an area where page breaks are
3516: prohibited, the distance between two boxes, the position of the reference axis
3517: of a box, the interline spacing, the indentation of the first line, the
1.18 cvs 3518: visibility, the depth (z-order), or the character set.</p>
1.30 cvs 3519:
3520: <p>The presentation rules associated with reference attributes, it is possible
3521: to use the element designated by the attribute as a reference box in a
3522: positional or extent rule. This element is represented in the <a
1.18 cvs 3523: href="#sectc4218">position</a> or <a href="#sectc4219">extent</a> rule by the
3524: keyword <tt>Referred</tt>.</p>
1.30 cvs 3525:
1.18 cvs 3526: <blockquote class="example">
1.30 cvs 3527: <p><strong>Example:</strong></p>
3528:
3529: <p>In all structure schemas, there is a global Language attribute defined as
3530: follows:</p>
3531: <pre>ATTR
1.18 cvs 3532: Language = TEXT;</pre>
1.30 cvs 3533:
3534: <p>The following rules would make French text be displayed in roman
3535: characters and English text be displayed in italics:</p>
3536: <pre>ATTRIBUTES
1.1 cvs 3537: Language = 'French' :
1.6 cvs 3538: Style : Roman;
1.1 cvs 3539: Language = 'English' :
1.18 cvs 3540: Style : Italics;</pre>
1.30 cvs 3541:
3542: <p>Using these rules, when the user puts the Language attribute with the
3543: value 'English' on the summary of a document, every character string
3544: (terminal elements) contained in the summary are displayed in italics. See
3545: the <a href="#sectd42252"><tt>Style</tt> rule</a>.</p>
1.18 cvs 3546: </blockquote>
1.30 cvs 3547:
1.18 cvs 3548: <blockquote class="example">
1.30 cvs 3549: <p><strong>Example:</strong></p>
3550:
3551: <p>A numeric attribute representing the importance of the part of the
3552: document to which it is attached can be defined:</p>
3553: <pre>ATTR
1.18 cvs 3554: Importance = INTEGER;</pre>
1.30 cvs 3555:
3556: <p>In the presentation schema, the importance of an element is reflected in
3557: the choice of character size, using the following rules.</p>
3558: <pre>ATTRIBUTES
1.1 cvs 3559: Importance < 2 :
3560: Size : 1;
3561: Importance IN [2..4] :
3562: Size : Importance;
3563: Importance = 10 :
3564: Size : 5;
1.30 cvs 3565: Importance > 4 :
1.18 cvs 3566: Size : 4;</pre>
1.30 cvs 3567:
3568: <p>Thus, the character size corresponds to the value of the Importance
3569: attribute; its value is</p>
3570: <ul>
3571: <li>the value of the Importance attribute when the value is between 2 and
3572: 4 (inclusive),</li>
3573: <li>1, when the value of the Importance attribute is less than 2,</li>
3574: <li>4, when the value of the Importance attribute is greater than 4,</li>
3575: <li>5, when the value of the Importance attribute is 10.</li>
3576: </ul>
3577:
3578: <p>The last case (value 5) must be defined before the case which handles all
3579: Importance values greater than 4, because the two rules are not disjoint and
3580: the first one defined will have priority. Otherwise, when the Importance
3581: attribute has value 10, the font size will be 4.</p>
1.18 cvs 3582: </blockquote>
1.30 cvs 3583:
1.18 cvs 3584: <blockquote class="example">
1.30 cvs 3585: <p><strong>Example:</strong></p>
3586:
3587: <p>Suppose the structure defines a list element which can have an attribute
3588: defining the type of list (numbered or not):</p>
3589: <pre>STRUCT
1.1 cvs 3590: list (ATTR list_type = enumeration, dash)
1.18 cvs 3591: = LIST OF (list_item = TEXT);</pre>
1.30 cvs 3592:
3593: <p>Then, the presentation schema could use the attribute placed on the list
3594: element to put either a dash or a number before the each element of the
3595: list:</p>
3596: <pre>ATTRIBUTES
1.1 cvs 3597: list_type (list_item) = enumeration :
3598: CreateBefore (NumberBox);
3599: list_type (list_item) = dash :
1.18 cvs 3600: CreateBefore (DashBox);</pre>
3601: </blockquote>
1.30 cvs 3602:
1.18 cvs 3603: <blockquote class="example">
1.30 cvs 3604: <p><strong>Example:</strong></p>
3605:
3606: <p>Suppose that two attributes are defined in the structure schema. The
3607: first is a numeric global attribute called ``version''. The other is a
3608: local attribute defined on the root of the document called
3609: ``Document_version'':</p>
3610: <pre>STRUCTURE Document
1.1 cvs 3611: ATTR
3612: version = INTEGER;
3613: STRUCT
3614: Document (ATTR Document_version = INTEGER) =
3615: BEGIN
3616: SomeElement ;
3617: ...
3618: SomeOtherElement ;
3619: END ;
1.18 cvs 3620: ...</pre>
1.30 cvs 3621:
3622: <p>These attributes can be used in the presentation schema to place change
3623: bars in the margin next to elements whose version attribute has a value
3624: equal to the Document_version attribute of the root and to place a star in
3625: margin of elements whose version attribute is less than the value of the
3626: root's Document_version attribute:</p>
3627: <pre>ATTRIBUTES
1.1 cvs 3628: version EQUAL Document_version :
3629: CreateBefore (ChangeBarBox) ;
3630: version LESS Document_version :
1.18 cvs 3631: CreateBefore (StarBox) ;</pre>
3632: </blockquote>
3633: </div>
1.1 cvs 3634:
1.18 cvs 3635: <div class="subsection">
1.30 cvs 3636: <h3><a name="sectc4212">Value transmission rules</a></h3>
1.1 cvs 3637:
1.30 cvs 3638: <p>The last section of a presentation schema, which is optional, serves to
1.1 cvs 3639: defines the way in which a document transmits certain values to its
1.18 cvs 3640: sub-documents. A sub-document is an document <a
3641: href="#inclusion">included</a> without expansion or with partial expansion.
1.1 cvs 3642: The primary document can transmit to its sub-documents the values of certain
3643: counters or the textual content of certain of its elements, as a function of
1.18 cvs 3644: their type.</p>
1.30 cvs 3645:
3646: <p>The sub-documents receive these values in attributes which must be defined
3647: in their structure schema as local attributes of the root element. The types
3648: of these attributes must correspond to the type of the value which they
3649: receive: numeric attributes for receiving the value of a counter, textual
3650: attributes for receiving the content of an element.</p>
3651:
3652: <p>In the structure schema of the primary document, there appears at the end,
1.18 cvs 3653: after the <tt>TRANSMIT</tt> keyword, a sequence of transmission rules. Each
1.1 cvs 3654: rule begins with the name of the counter to transmit or of the element type
3655: whose textual content will be transmitted. This name is followed by the
1.18 cvs 3656: keyword <tt>To</tt> and the name of the attribute of the sub-document to which
1.1 cvs 3657: the value is transmitted. The sub-document class is indicated between
3658: parentheses after the name of the attribute. The transmission rule ends with
1.18 cvs 3659: a semicolon.</p>
1.30 cvs 3660: <pre> TransmitSeq = Transmit < Transmit > .
1.1 cvs 3661: Transmit = TypeOrCounter 'To' ExternAttr
3662: '(' ElemID ')' ';' .
3663: TypeOrCounter = CounterID / ElemID .
1.18 cvs 3664: ExternAttr = NAME .</pre>
1.30 cvs 3665:
1.18 cvs 3666: <blockquote class="example">
1.30 cvs 3667: <p><strong>Example:</strong></p>
3668:
3669: <p>Consider a Book document class which includes instances of the Chapter
3670: document class. These classes might have the following schemas:</p>
3671: <pre>STRUCTURE Book
1.1 cvs 3672: STRUCT
3673: Book = BEGIN
3674: Title = Text;
3675: Body = LIST OF (Chapter INCLUDED);
3676: END;
3677: ...
3678:
3679: STRUCTURE Chapter
3680: STRUCT
3681: Chapter (ATTR FirstPageNum = Integer;
3682: ChapterNum = Integer;
3683: CurrentTitle = Text) =
1.6 cvs 3684: BEGIN
3685: ChapterTitle = Text;
3686: ...
3687: END;
1.18 cvs 3688: ...</pre>
1.30 cvs 3689:
3690: <p>Then the presentation schema for books could define chapter and page
3691: counters. The following transmission rules in the book presentation schema
3692: would transmit values for the three attributes defined at the root of each
3693: chapter sub-document.</p>
3694: <pre>PRESENTATION Book;
1.1 cvs 3695: VIEWS
3696: Full_text;
3697: COUNTERS
3698: ChapterCtr: Rank of Chapter;
3699: PageCtr: Rank of Page(Full_text);
3700: ...
3701: TRANSMIT
3702: PageCtr TO FirstPageNum(Chapter);
3703: ChapterCtr TO ChapterNum(Chapter);
3704: Title TO CurrentTitle(Chapter);
1.18 cvs 3705: END</pre>
1.30 cvs 3706:
3707: <p>Thus, each chapter included in a book can number its pages as a function
3708: of the number of pages preceding it in the book, can make the chapter's
3709: number appear before the number of each of its sections, or can place the
3710: title of the book at the top of each page.</p>
1.18 cvs 3711: </blockquote>
3712: </div>
1.1 cvs 3713:
1.18 cvs 3714: <div class="subsection">
1.30 cvs 3715: <h3><a name="sectc4213">Presentation rules</a></h3>
1.1 cvs 3716:
1.30 cvs 3717: <p>Whether defining the appearance of a presentation or page layout box, an
1.1 cvs 3718: element type, or an attribute value, the set of presentation rules that apply
1.18 cvs 3719: is always defined in the same way.</p>
1.30 cvs 3720:
3721: <p>Normally, a set of presentation rules is placed between the keywords
1.18 cvs 3722: <tt>BEGIN</tt> and <tt>END</tt>, the keyword <tt>END</tt> being followed by a
1.1 cvs 3723: semicolon. The first section of this block defines the rules that apply to
1.18 cvs 3724: the primary view, if the <a href="#sectc427">default rules</a> are not
1.1 cvs 3725: completely suitable. Next comes the rules which apply to specific other
3726: views, with a rule sequence for each view for which the default rules are not
3727: satisfactory. If the default rules are suitable for the non-primary views,
3728: there will not be any specific rules for these views. If there is only one
1.18 cvs 3729: rule which applies to all views then the keywords <tt>BEGIN</tt> and
3730: <tt>END</tt> need not appear.</p>
1.30 cvs 3731:
3732: <p>For each view, it is only necessary to specify those rules which differ
3733: from the default rules for the view, so that for certain views (or even all
3734: views), there may be no specific rules.</p>
3735:
3736: <p>The specific rules for a non-primary view are introduced by the <a
1.18 cvs 3737: name="inkeyword"><tt>IN</tt> keyword</a>, followed by the view name. The
3738: rules for that view follow, delimited by the keywords <tt>BEGIN</tt> and
3739: <tt>END</tt>, or without these two keywords when there is only one rule.</p>
1.30 cvs 3740:
3741: <p><strong>Note:</strong> the view name which follows the <tt>IN</tt> keyword
1.1 cvs 3742: must not be the name of the primary view, since the rules for that view are
1.18 cvs 3743: found before the rules for the other views.</p>
1.30 cvs 3744:
3745: <p>Within each block concerning a view, other blocks can appear, delimited by
3746: the same keywords <tt>BEGIN</tt> and <tt>END</tt>. Each of these blocks
3747: gathers the presentation rules that apply, for a given view, only when a given
1.1 cvs 3748: condition is satisfied. Each block is preceded by a condition introduced by
1.18 cvs 3749: the <tt>IF</tt> keyword. If such a conditional block contains only one rule,
3750: the keywords <tt>BEGIN</tt> and <tt>END</tt> can be omitted.</p>
1.30 cvs 3751:
3752: <p>Although the syntax allows any presentation rule to appear in a conditional
1.18 cvs 3753: block, only <a href="#sectc4232">creation rules</a> are allowed after any
3754: condition; other rules are allowed only after conditions <tt>Within</tt> and
1.1 cvs 3755: ElemID. In addition, the following rules cannot be conditional:
1.18 cvs 3756: <tt>PageBreak, LineBreak, Inline, Gather</tt>.</p>
1.30 cvs 3757:
3758: <p>For a given view, the rules that apply without any condition must appear
1.1 cvs 3759: before the first conditional block. If some rules apply only when none of the
3760: specified condition holds, they are grouped in a block preceded by the keyword
1.18 cvs 3761: <tt>Otherwise</tt>, and that block must appear after the last conditionnal
3762: block concerning the same view.</p>
1.30 cvs 3763: <pre> ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 3764: 'END' ';' /
3765: ViewRules / CondRules / Rule .
3766: RulesAndCond = CondRules / Rule .
3767: ViewRules = 'IN' ViewID CondRuleSeq .
1.30 cvs 3768: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
1.1 cvs 3769: CondRules / Rule .
1.30 cvs 3770: CondRules = CondRule < CondRule >
1.1 cvs 3771: [ 'Otherwise' RuleSeq ] .
3772: CondRule = 'IF' ConditionSeq RuleSeq .
1.30 cvs 3773: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' /
1.18 cvs 3774: Rule .</pre>
1.30 cvs 3775:
1.18 cvs 3776: <blockquote class="example">
1.30 cvs 3777: <p><strong>Example:</strong></p>
3778:
3779: <p>The following rules for a report's title make the title visible in the
3780: primary view and invisible in the table of contents and in the formula views
3781: (see the <a href="#sectc4224"><tt>Visibility</tt> rule</a>).</p>
3782: <pre>Title : BEGIN
1.1 cvs 3783: Visibility : 1;
3784: ... {Other rules for the primary view}
3785: IN Table_of_contents
3786: Visibility : 0;
3787: IN Formulas
3788: Visibility : 0;
1.18 cvs 3789: END;</pre>
3790: </blockquote>
3791: </div>
1.1 cvs 3792:
1.18 cvs 3793: <div class="subsection">
1.30 cvs 3794: <h3><a name="sectc4214">Conditions applying to presentation rules</a></h3>
1.1 cvs 3795:
1.30 cvs 3796: <p>Many conditions can be applied to presentation rules. Conditions allow
1.1 cvs 3797: certain presentation rules to apply only in certain cases. These conditions
3798: can be based on the structural position of the element. They can be based on
3799: whether the element has references, and what type of references, whether the
3800: element has attributes, whether the element is empty or not. They can also be
1.18 cvs 3801: based on the value of a counter.</p>
1.30 cvs 3802:
3803: <p>It is possible to specify several conditions which must all be true for the
1.18 cvs 3804: rules to apply.</p>
1.30 cvs 3805:
3806: <p>A set of conditions is specified by the <tt>IF</tt> keyword. This keyword
3807: is followed by the sequence of conditions, separated by the <tt>AND</tt>
3808: keyword. Each condition is specified by a keyword which defines the condition
3809: type. In some cases, the keyword is followed by other data, which specify the
3810: condition more precisely.</p>
3811:
3812: <p>An elementary condition can be negative; it is then preceded by the
1.18 cvs 3813: <tt>NOT</tt> keyword.</p>
1.30 cvs 3814:
3815: <p>When the presentation rule(s) controlled by the condition apply to a
3816: reference element or a reference attribute, an elementary condition can also
3817: apply to element referred by this reference. The <tt>Target</tt> keyword is
3818: used for that purpose. It must appear before the keyword defining the
3819: condition type.</p>
1.18 cvs 3820: <pre> CondRule ='IF' ConditionSeq RuleSeq .
1.30 cvs 3821: ConditionSeq = Condition < 'AND' Condition > .
1.1 cvs 3822: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
3823: ConditionElem ='First' / 'Last' /
3824: [ 'Immediately' ] 'Within' [ NumParent ]
3825: ElemID [ ExtStruct ] /
3826: ElemID /
3827: 'Referred' / 'FirstRef' / 'LastRef' /
3828: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
3829: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
3830: 'UserPage' / 'StartPage' / 'ComputedPage' /
3831: 'Empty' /
3832: '(' [ MinMax ] CounterName CounterCond ')' /
3833: CondPage '(' CounterID ')' .
3834: NumParent = [ GreaterLess ] NParent .
1.30 cvs 3835: GreaterLess ='>' / '<' .
1.1 cvs 3836: NParent = NUMBER.
1.6 cvs 3837: ExtStruct ='(' ElemID ')' .
1.30 cvs 3838: CounterCond ='<' MaxCtrVal / '>' MinCtrVal /
1.1 cvs 3839: '=' EqCtrVal /
3840: 'IN' '[' ['-'] MinCtrBound '.' '.'
3841: ['-'] MaxCtrBound ']' .
3842: PageCond ='Even' / 'Odd' / 'One' .
3843: MaxCtrVal = NUMBER .
3844: MinCtrVal = NUMBER .
3845: EqCtrVal = NUMBER .
3846: MaxCtrBound = NUMBER .
1.18 cvs 3847: MinCtrBound = NUMBER .</pre>
1.1 cvs 3848:
1.18 cvs 3849: <div class="subsubsection">
3850: <h4><a name="sectd42141">Conditions based on the logical position of the
3851: element</a></h4>
1.30 cvs 3852:
3853: <p>The condition can be on the position of the element in the document's
3854: logical structure tree. It is possible to test whether the element is the
3855: first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
3856: not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>). These
1.18 cvs 3857: conditions can be associated only with <a href="#sectc4232">creation
3858: rules</a>.</p>
1.30 cvs 3859:
3860: <p>It is also possible to test if the element is contained in an element of a
1.18 cvs 3861: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). The type
3862: is indicated after the keyword <tt>Within</tt>. If that element type is
1.1 cvs 3863: defined in a structure schema which is not the one which corresponds to the
3864: presentation schema, the type name of this element must be followed, between
1.18 cvs 3865: parentheses, by the name of the structure schema which defines it.</p>
1.30 cvs 3866:
3867: <p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
1.18 cvs 3868: condition is satisfied only if the <em>parent</em> element has the type
3869: indicated. If the word <tt>Immediately</tt> is missing, the condition is
3870: satisfied if any <em>ancestor</em> has the type indicated.</p>
1.30 cvs 3871:
3872: <p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.1 cvs 3873: type. It specifies the number of ancestors of the indicated type that must be
3874: present for the condition to be satisfied. If the keyword
1.18 cvs 3875: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
3876: element must have the indicated type. The integer <i>n</i> must be positive
1.30 cvs 3877: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
1.1 cvs 3878: maximum or minimum number of ancestors. If these symbols are missing, the
1.18 cvs 3879: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
1.30 cvs 3880: this number is missing, it is equivalent to > 0.</p>
3881:
3882: <p>If the condition applies to presentation rules associated with an
3883: attribute, in the <tt>ATTRIBUTES</tt> section of the presentation schema, the
3884: condition can be simply an element name. Presentation rules are then executed
3885: only if the attribute is attached to an element of that type. The keyword
3886: <tt>NOT</tt> before the element name indicates that the presentation rules
3887: must be executed only if the element is not of the type indicated.</p>
1.18 cvs 3888: </div>
1.1 cvs 3889:
1.18 cvs 3890: <div class="subsubsection">
1.30 cvs 3891: <h4><a name="sectd42142">Conditions on references</a></h4>
3892:
3893: <p>References may be taken into account in conditions, which can be based on
3894: the fact that the element, or one of its ancestors, is designated by a at
3895: least one reference (<tt>Referred</tt>) or by none (<tt>NOT
3896: Referred</tt>).</p>
3897:
3898: <p>If the element or attribute to which the condition is attached is a
3899: reference, the condition can be based on the fact that it acts as the first
3900: reference to the designated element (<tt>FirstRef</tt>), or as the last
3901: (<tt>LastRef</tt>), or as a reference to an element located in another
3902: document (<tt>ExternalRef</tt>) or in the same document
3903: (<tt>InternalRef</tt>).</p>
1.1 cvs 3904:
1.30 cvs 3905: <p>The condition can also be based on the fact that the element is an <a
1.18 cvs 3906: href="#inclusion">inclusion</a>. This is noted (<tt>CopyRef</tt>).</p>
1.30 cvs 3907:
3908: <p>Like all conditions, conditions on references can be inverted by the
1.18 cvs 3909: <tt>NOT</tt> keyword. These conditions can be associated only with <a
3910: href="#sectc4232">creation rules</a>.</p>
3911: </div>
1.1 cvs 3912:
1.18 cvs 3913: <div class="subsubsection">
1.30 cvs 3914: <h4><a name="sectd42143">Conditions on logical attributes</a></h4>
3915:
3916: <p>The condition can be based on the presence or absence of attributes
3917: associated with the element, no matter what the attributes or their values.
3918: The <tt>AnyAttributes</tt> keyword expresses this condition.</p>
1.1 cvs 3919:
1.30 cvs 3920: <p>If the condition appears in the presentation rules of an attribute, the
1.18 cvs 3921: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
1.1 cvs 3922: the rules must only be applied if this attribute is the first attribute for
3923: the element or if it is the last (respectively). These conditions can also be
1.18 cvs 3924: inverted by the <tt>NOT</tt> keyword. These conditions can be associated only
3925: with <a href="#sectc4232">creation rules</a>.</p>
1.30 cvs 3926:
3927: <p>It is also possible to apply certain presentation rules only when the
3928: element being processed or one of its ancestors has a certain attribute,
3929: perhaps with a certain value. This can be done in the <a
1.18 cvs 3930: href="#sectc4210"><tt>ATTRIBUTES</tt> section</a>.</p>
3931: </div>
1.1 cvs 3932:
1.18 cvs 3933: <div class="subsubsection">
1.30 cvs 3934: <h4><a name="sectd42144">Conditions on page breaks</a></h4>
1.1 cvs 3935:
1.30 cvs 3936: <p>The page break base type (and only this type) can use the following
1.18 cvs 3937: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, and <tt>UserPage</tt>.
3938: The <tt>ComputedPage</tt> condition indicates that the presentation rule(s)
1.1 cvs 3939: should apply if the page break was created automatically by Thot; the
1.18 cvs 3940: <tt>StartPage</tt> condition is true if the page break is generated before the
3941: element by the <tt>Page</tt> rule; and the <tt>UserPage</tt> condition applies
3942: if the page break was inserted by the user.</p>
1.30 cvs 3943:
3944: <p>These conditions can be associated only with <a href="#sectc4232">creation
1.18 cvs 3945: rules</a>.</p>
3946: </div>
1.1 cvs 3947:
1.18 cvs 3948: <div class="subsubsection">
1.30 cvs 3949: <h4><a name="sectd42145">Conditions on the element's content</a></h4>
1.1 cvs 3950:
1.30 cvs 3951: <p>The condition can be based on whether or not the element is empty. An
3952: element which has no children or whose leaves are all empty is considered to
3953: be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
3954: optionally preceded by the <tt>NOT</tt> keyword. This condition can be
3955: associated only with <a href="#sectc4232">creation rules</a>.</p>
1.18 cvs 3956: </div>
1.1 cvs 3957:
1.18 cvs 3958: <div class="subsubsection">
1.30 cvs 3959: <h4><a name="sectd42146">Conditions on counters</a></h4>
1.1 cvs 3960:
1.30 cvs 3961: <p>Presentation rules can apply when the counter's value is one, is even or
3962: odd, is equal, greater than or less than a given value or falls in a range of
1.1 cvs 3963: values. This is particularly useful for creating header and footer boxes.
1.18 cvs 3964: These conditions can be associated only with <a href="#sectc4232">creation
3965: rules</a>.</p>
1.30 cvs 3966:
3967: <p>To compare the value of a counter to a given value, a comparison is given
1.1 cvs 3968: between parentheses. The comparison is composed of the counter name followed
3969: by an equals, greater than, or less than sign and the value to which the
3970: counter will be compared. A test for whether or not a counter's value falls
3971: in a range also appears within parentheses. In this case, the counter name is
1.18 cvs 3972: followed by the <tt>IN</tt> keyword and the range definition within brackets.
3973: The <tt>Even</tt>, <tt>Odd</tt> and <tt>One</tt> are used to test a counter's
3974: value and are followed by the counter name between parentheses.</p>
1.30 cvs 3975:
3976: <p>The list of possible conditions on counters is:</p>
1.18 cvs 3977: <dl>
1.30 cvs 3978: <dt><tt>Even (Counter)</tt></dt>
3979: <dd>the box is created only if the counter has an even value.</dd>
3980: <dt><tt>Odd (Counter)</tt></dt>
3981: <dd>the box is created only if the counter has an odd value.</dd>
3982: <dt><tt>One (Counter)</tt></dt>
3983: <dd>the box is created only the counter's value is 1.</dd>
3984: <dt><tt>NOT One (Counter)</tt></dt>
3985: <dd>the box is created, unless the counter's value is 1.</dd>
3986: <dt><tt>(Counter < Value)</tt></dt>
3987: <dd>the box is created only if the counter's value is less than
3988: Value.</dd>
3989: <dt><tt>(Counter > Value)</tt></dt>
3990: <dd>the box is created only if the counter's value is greater than
3991: Value.</dd>
3992: <dt><tt>(Counter = Value)</tt></dt>
3993: <dd>the box is created only if the counter's value is equal to Value.</dd>
3994: <dt><tt>NOT (Counter = Value)</tt></dt>
3995: <dd>the is created only if the counter's value is different than
3996: Value.</dd>
3997: <dt><tt>(Counter IN [MinValue..MaxValue])</tt></dt>
3998: <dd>the box is created only if the counter's value falls in the range
3999: bounded by MinValue and MaxValue (inclusive).</dd>
4000: <dt><tt>NOT (Counter IN [MinValue..MaxValue])</tt></dt>
4001: <dd>the box is created only if the value of the counter does not fall in
4002: the range bounded by MinValue and MaxValue (inclusive).</dd>
1.18 cvs 4003: </dl>
1.30 cvs 4004:
4005: <p><strong>Note:</strong> the <tt>NOT Even</tt> and <tt>NOT Odd</tt>
4006: conditions are syntactically correct but can be expressed more simply by
4007: <tt>Odd</tt> and <tt>Even</tt>, respectively.</p>
1.18 cvs 4008: </div>
4009: </div>
1.1 cvs 4010:
1.18 cvs 4011: <div class="subsection">
1.30 cvs 4012: <h3><a name="sectc4215">A presentation rule</a></h3>
1.1 cvs 4013:
1.30 cvs 4014: <p>A presentation rule defines either a presentation parameter or presentation
1.18 cvs 4015: function. The parameters are:</p>
4016: <ul>
1.30 cvs 4017: <li>the position of the vertical and horizontal reference axes of the
4018: box,</li>
4019: <li>the position of the box in relation to other boxes,</li>
4020: <li>the height or width of the box, with overflow exceptions,</li>
4021: <li>the margins, padding and borders of the box,</li>
4022: <li>the characteristics of the lines contained in the box: linespacing,
4023: indentation of the first line, justification, hyphenation,</li>
4024: <li>the conditions for breaking the box across pages,</li>
4025: <li>the characteristics of the characters contained in the box: size, font,
4026: style, underlining,</li>
4027: <li>the depth of the box among overlapping boxes (often called stacking
4028: order),</li>
4029: <li>the characteristics of graphic elements contained in the box: style and
4030: thickness of lines, fill pattern for closed objects,</li>
4031: <li>the colors in text, graphics, pictures, and symbols contained in the box
4032: are displayed or printed,</li>
4033: <li>for presentation boxes only, the contents of the box.</li>
4034: </ul>
4035:
4036: <p>The <a name="presfunct">presentation functions</a> are:</p>
4037: <ul>
4038: <li>the creation of a presentation box</li>
4039: <li>the line-breaking or page-breaking style,</li>
4040: <li>the copying of another box,</li>
4041: <li>the display of the box background and border,</li>
4042: <li>the display of a background picture and its aspect.</li>
4043: </ul>
4044:
4045: <p>For each box and each view, every presentation parameter is defined once
4046: and only once, either explicitly or by the <a href="#sectc427">default
4047: rules</a>. In contrast, presentation functions are not obligatory and can
4048: appear many times for the same element. for example an element can create
4049: many presentation boxes. Another element may not use any presentation
1.18 cvs 4050: functions.</p>
1.30 cvs 4051:
4052: <p>Each rule defining a presentation parameter begins with a keyword followed
4053: by a colon. The keyword indicates the parameter which is the subject of the
1.18 cvs 4054: rule. After the keyword and the colon, the remainder of the rule varies. All
4055: rules are terminated by a semicolon.</p>
4056: <pre> Rule = PresParam ';' / PresFunc ';' .
1.6 cvs 4057: PresParam ='VertRef' ':' PositionHoriz /
4058: 'HorizRef' ':' PositionVert /
4059: 'VertPos' ':' VPos /
4060: 'HorizPos' ':' HPos /
4061: 'Height' ':' Dimension /
4062: 'Width' ':' Dimension /
4063: 'VertOverflow' ':' Boolean /
1.1 cvs 4064: 'HorizOverflow' ':' Boolean /
1.26 cvs 4065: 'MarginTop' ':' MarginWidth /
4066: 'MarginRight' ':' MarginWidth /
4067: 'MarginBottom' ':' MarginWidth /
4068: 'MarginLeft' ':' MarginWidth /
4069: 'PaddingTop' ':' PaddingWidth /
4070: 'PaddingRight' ':' PaddingWidth /
4071: 'PaddingBottom' ':' PaddingWidth /
4072: 'PaddingLeft' ':' PaddingWidth /
4073: 'BorderTopWidth' ':' BorderWidth /
4074: 'BorderRightWidth' ':' BorderWidth /
4075: 'BorderBottomWidth' ':' BorderWidth /
4076: 'BorderLeftWidth' ':' BorderWidth /
4077: 'BorderTopColor' ':' BorderColor /
4078: 'BorderRightColor' ':' BorderColor /
4079: 'BorderBottomColor' ':' BorderColor /
4080: 'BorderLeftColor' ':' BorderColor /
4081: 'BorderTopStyle' ':' BorderStyle /
4082: 'BorderRightStyle' ':' BorderStyle /
4083: 'BorderBottomStyle' ':' BorderStyle /
4084: 'BorderLeftStyle' ':' BorderStyle .
1.6 cvs 4085: 'LineSpacing' ':' DistanceInherit /
4086: 'Indent' ':' DistanceInherit /
4087: 'Adjust' ':' AdjustInherit /
4088: 'Justify' ':' BoolInherit /
4089: 'Hyphenate' ':' BoolInherit /
4090: 'PageBreak' ':' Boolean /
4091: 'LineBreak' ':' Boolean /
4092: 'InLine' ':' Boolean /
4093: 'NoBreak1' ':' AbsDist /
4094: 'NoBreak2' ':' AbsDist /
4095: 'Gather' ':' Boolean /
4096: 'Visibility' ':' NumberInherit /
4097: 'Size' ':' SizeInherit /
4098: 'Font' ':' NameInherit /
4099: 'Style' ':' StyleInherit /
1.23 cvs 4100: 'Weight' ':' WeightInherit /
1.6 cvs 4101: 'Underline' ':' UnderLineInherit /
4102: 'Thickness' ':' ThicknessInherit /
4103: 'Depth' ':' NumberInherit /
4104: 'LineStyle' ':' LineStyleInherit /
4105: 'LineWeight' ':' DistanceInherit /
4106: 'FillPattern' ':' NameInherit /
4107: 'Background' ':' NameInherit /
1.13 cvs 4108: 'Foreground' ':' NameInherit /
1.6 cvs 4109: 'Content' ':' VarConst .
1.1 cvs 4110: PresFunc = Creation '(' BoxID ')' /
4111: 'Line' /
4112: 'NoLine' /
4113: 'Page' '(' BoxID ')' /
1.13 cvs 4114: 'Copy' '(' BoxTypeToCopy ')' /
4115: 'ShowBox' /
1.18 cvs 4116: 'BackgroundPicture' ':' FileName /
4117: 'PictureMode' ':' PictMode /</pre>
4118: </div>
4119:
4120: <div class="subsection">
1.30 cvs 4121: <h3><a name="sectc4216">Box axes</a></h3>
1.18 cvs 4122:
1.30 cvs 4123: <p>The position of the middle axes <tt>VMiddle</tt> and <tt>HMiddle</tt> in
1.1 cvs 4124: relation to their box is always calculated automatically as a function of the
4125: height and width of the box and is not specified by the presentation rules. In
4126: the presentation schema, these middle axes are used only to position their box
4127: with respect to another by specifying the distance between the middle axis and
1.18 cvs 4128: an axis or a side of another box (see the <a href="#sectc4218">relative
4129: position</a>).</p>
1.30 cvs 4130:
4131: <p>The reference axes of a box are also used to position their box in relation
4132: to another, but in contrast to the middle axes, the presentation schema must
4133: make their position explicit, either in relation to a side or the middle axis
4134: of the box itself, or in relation to an axis of an enclosed box.</p>
4135:
4136: <p>Only boxes of base elements have predefined reference axes. For character
1.1 cvs 4137: string boxes, the horizontal reference axis is the baseline of the characters
4138: (the line which passes immediately under the upper-case letters, ignoring the
4139: letter Q) and the vertical reference axis is at the left edge of the first
1.18 cvs 4140: character of the string.</p>
1.30 cvs 4141:
4142: <p>The positions of a box's reference axes are defined by the <tt>VertRef</tt>
1.18 cvs 4143: and <tt>HorizRef</tt> rules which specify the <a href="#distance">distance</a>
1.1 cvs 4144: between the reference axis and an axis or parallel side of the same box or of
1.18 cvs 4145: an enclosed box.</p>
4146: <pre> 'VertRef' ':' PositionHoriz
4147: 'HorizRef' ':' PositionVert</pre>
1.30 cvs 4148:
1.18 cvs 4149: <blockquote class="example">
1.30 cvs 4150: <p><strong>Example:</strong></p>
4151:
4152: <p>If, in the structure schema for mathematical formulas, the fraction
4153: element is defined by</p>
4154: <pre>Fraction = BEGIN
1.1 cvs 4155: Numerator = Expression;
4156: Denominator = Expression;
1.18 cvs 4157: END;</pre>
1.30 cvs 4158:
4159: <p>then the horizontal reference axis of the fraction can be positioned on
4160: top of the denominator by the rule:</p>
4161: <pre>Fraction :
1.1 cvs 4162: BEGIN
4163: HorizRef : Enclosed Denominator . Top;
4164: ...
1.18 cvs 4165: END;</pre>
1.30 cvs 4166:
4167: <p>To put the horizontal reference axis of a column at its middle:</p>
4168: <pre>Column :
1.1 cvs 4169: BEGIN
4170: HorizRef : * . HMiddle;
4171: ...
1.18 cvs 4172: END;</pre>
4173: </blockquote>
4174: </div>
1.1 cvs 4175:
1.18 cvs 4176: <div class="subsection">
1.30 cvs 4177: <h3><a name="sectc4217">Distance units</a></h3>
1.1 cvs 4178:
1.30 cvs 4179: <p>Some distances and dimensions appear in many rules of a presentation
4180: schema, especially in position rules (<tt>VertPos, HorizPos</tt>), in extent
4181: rules for boxes (<tt>Height, Width</tt>), in rules defining lines
4182: (<tt>LineSpacing, Indent</tt>), in rules controlling pagination (<tt>NoBreak1,
4183: NoBreak2</tt>) and in rules specifying the thickness of strokes
4184: (<tt>LineWeight</tt>).</p>
4185:
4186: <p>In all these rules, the distance or extent can be expressed</p>
4187: <ul>
4188: <li>either in relative units, which depend on the size of the characters in
4189: the current font: height of the element's font or height of the letter
4190: 'x',</li>
4191: <li>or in absolute units: centimeter, millimeter, inch, typographer's point,
4192: pica or pixel.</li>
4193: </ul>
4194:
4195: <p>Units can be chosen freely. Thus, it is possible to use relative units in
4196: one rule, centimeters in the next rule, and typographer's points in
4197: another.</p>
4198:
4199: <p>Absolute units are used to set rigid rules for the appearance of documents.
4200: In contrast, relative units allow changes of scale. The editor lets the value
4201: of relative units be changed dynamically. Such changes affect every box using
1.1 cvs 4202: relative units simultaneously and in the same proportion. Changing the value
4203: of the relative units affects the size of the characters and graphical
1.18 cvs 4204: elements, and the size of the boxes and the distances between them.</p>
1.30 cvs 4205:
4206: <p>A <a name="distance">distance</a> or extent is specified by a number, which
1.1 cvs 4207: may be followed by one or more spaces and a units keyword. When there is no
4208: units keyword, the number specifies the number of relative units, where a
4209: relative unit is the height of a character in the current font (an em). When
4210: the number is followed by a units keyword, the keyword indicates the type of
1.18 cvs 4211: absolute units:</p>
4212: <ul>
1.30 cvs 4213: <li><tt>em</tt>: height of the element's font,</li>
4214: <li><tt>ex</tt>: height of the letter 'x',</li>
4215: <li><tt>cm</tt>: centimeter,</li>
4216: <li><tt>mm</tt>: millimeter,</li>
4217: <li><tt>in</tt>: inch (1 in = 2.54 cm),</li>
4218: <li><tt>pt</tt>: point (1 pt = 1/72 in),</li>
4219: <li><tt>pc</tt>: pica (1 pc = 12 pt),</li>
4220: <li><tt>px</tt>: pixel.</li>
1.18 cvs 4221: </ul>
1.30 cvs 4222:
4223: <p>Whatever the chosen unit, relative or absolute, the number is not
4224: necessarily an integer and may be expressed in fixed point notation (using the
4225: American convention of a period to express the decimal point).</p>
4226:
4227: <p>If the distance appears in a presentation rule for a numeric attribute, the
1.1 cvs 4228: number can be replaced by the name of an attribute. In this case, the value
4229: of the attribute is used. Obviously, the attribute name cannot be followed by
4230: a decimal point and a fractional part, but it can be followed a units keyword.
1.18 cvs 4231: However, the choice of units is limited to em, ex, pt and px.</p>
4232: <pre> Distance = [ Sign ] AbsDist .
1.1 cvs 4233: Sign ='+' / '-' .
4234: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
4235: [ Unit ].
4236: IntegerOrAttr = IntegerPart / AttrID .
4237: IntegerPart = NUMBER .
4238: DecimalPart = NUMBER .
4239: Unit ='em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
1.18 cvs 4240: 'pc' / 'px' / '%' .</pre>
1.30 cvs 4241:
1.18 cvs 4242: <blockquote class="example">
1.30 cvs 4243: <p><strong>Example:</strong></p>
4244:
4245: <p>The following rules specify that a box has a height of 10.5 centimeters
4246: and a width of 5.3 ems:</p>
4247: <pre>Height : 10.5 cm;
1.18 cvs 4248: Width : 5.3;</pre>
4249: </blockquote>
4250: </div>
1.1 cvs 4251:
1.18 cvs 4252: <div class="subsection">
1.30 cvs 4253: <h3><a name="sectc4218">Relative positions</a></h3>
1.1 cvs 4254:
1.30 cvs 4255: <p>The positioning of boxes uses the eight axes and sides, the sides generally
1.1 cvs 4256: being used to define the juxtapositioning (vertical or horizontal) of boxes,
4257: the middle axes being used to define centering, and the reference axes being
1.18 cvs 4258: used for alignment.</p>
1.30 cvs 4259:
4260: <p>Two rules allow a box to be placed relative to other boxes. The
1.18 cvs 4261: <tt>VertPos</tt> rule positions the box vertically. The <tt>HorizPos</tt>
4262: rule positions the box horizontally. It is possible that a box's position
4263: could be entirely determined by other boxes positioned relative to it. In this
4264: case, the position is implicit and the word <tt>nil</tt> can be used to
4265: specify that no position rule is needed. Otherwise, an explicit rule must be
4266: given by indicating the axis or side which defines the position of the box,
4267: followed by an equals sign and the distance between between this axis or side
4268: and a parallel axis or side of another box, called the reference box. The box
4269: for which the rule is written will be positioned relative to the reference
4270: box.</p>
4271: <pre> 'VertPos' ':' VPos
1.6 cvs 4272: 'HorizPos' ':' HPos
4273: HPos = 'nil' / VertAxis '=' HorizPosition
4274: [ 'UserSpecified' ].
4275: VPos = 'nil' / HorizAxis '=' VertPosition
4276: [ 'UserSpecified' ].
1.1 cvs 4277: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
1.18 cvs 4278: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .</pre>
1.30 cvs 4279:
4280: <p>The reference box is an adjacent box: enclosing, enclosed or adjacent. When
4281: a rule is associated with a reference type attribute (and only in this case),
4282: it can be a box of the element designated by the attribute. The reference box
1.18 cvs 4283: can be either a presentation box previously defined in the <tt>BOXES</tt>
1.1 cvs 4284: section of the schema and created by a creation function, or the box
1.18 cvs 4285: associated with a structured element.</p>
1.30 cvs 4286:
4287: <p>The structural position of the reference box (relative to the box for which
1.18 cvs 4288: the rule is being written) is indicated by a keyword: <tt>Enclosing</tt>,
4289: <tt>Enclosed</tt>, or, for sibling boxes, <tt>Previous</tt> or <tt>Next</tt>.
1.1 cvs 4290: The reference attributes, or presentation boxes created by a reference
1.18 cvs 4291: attribute, the <tt>Referred</tt> keyword may be used to designate the element
4292: which the reference points to. The keyword <tt>Creator</tt> can be used in
1.1 cvs 4293: rules for presentation boxes to designate the box of the element which created
1.18 cvs 4294: the presentation box. Finally, the <tt>Root</tt> keyword can be used to
4295: designate the root of the document.</p>
1.30 cvs 4296:
4297: <p>When the keyword is ambiguous, it is followed by the name of an element
4298: type or presentation box which resolves the ambiguity (the <tt>Creator</tt>
4299: and <tt>Root</tt> keywords are never ambiguous). If this name is not given,
4300: then the first box encountered is used as the reference box. It is also
4301: possible to use just the name of an element type or presentation box without
4302: an initial keyword. In this case, a sibling having that name will be used. If
4303: the name is preceded by the keyword <tt>NOT</tt>, then the reference box will
4304: be the first box whose type is not the named one.</p>
4305:
4306: <p>In place of the box or type name, the keywords <tt>AnyElem</tt>,
1.18 cvs 4307: <tt>AnyBox</tt> and <tt>ElemWithAttr</tt> can be used, representing
1.17 cvs 4308: respectively, any structured element box, any presentation box, and the box
4309: corresponding to any structured element having a particular attribute,
4310: whatever its value; the name of this attribute must follow the keyword
1.18 cvs 4311: <tt>ElemWithAttr</tt>.</p>
1.30 cvs 4312:
4313: <p>A type name may be preceded by a star in order to resolve the ambiguity in
4314: the special case where the structure schema defines an <a
1.18 cvs 4315: href="#sectd3284">inclusion</a> without expansion (or with partial expansion)
4316: of the same type as an element of the scheme. For mark pairs (and only for <a
4317: href="#sectd3285">mark pairs</a>) the type name <em>must</em> be preceded by
4318: the <tt>First</tt> or <tt>Second</tt> keyword, which indicates which of the
4319: two marks of the pair should be used as the reference box.</p>
1.30 cvs 4320:
4321: <p>The star character ('<tt>*</tt>') used alone designates the box to which
4322: the rule applies (in this case, it is obviously useless to specify the type of
4323: the reference box).</p>
4324:
4325: <p>The keywords <tt>Enclosing</tt> and <tt>Enclosed</tt> can be used no matter
1.1 cvs 4326: what constructor defines the type to which the rule applies. When applied to
1.18 cvs 4327: the element which represents the entire document, <tt>Enclosing</tt>
1.1 cvs 4328: designates the window or page in which the document's image is displayed for
4329: the view to which the rule applies. A box or type name without a keyword is
4330: used for aggregate elements and designates another element of the same
4331: aggregate. It can also be used to designate a presentation or page layout
1.18 cvs 4332: box. The keywords <tt>Previous</tt> and <tt>Next</tt> are primarily used to
1.1 cvs 4333: denote list elements, but can also be used to denote elements of an
1.18 cvs 4334: aggregate.</p>
1.30 cvs 4335:
4336: <p>In the position rule, the structural position relative to the reference box
4337: is followed, after a period, by the name of an axis or side. The rule
4338: specifies its node's position as being some distance from this axis or side of
4339: the reference box. If this distance is zero, then the distance does not
4340: appear in the rule. Otherwise, it does appear as a positive or negative
4341: number (the sign is required for negative numbers). The sign takes into
4342: account the orientation of the coordinate axes: for top to bottom for the
4343: vertical axis and from left to right for the horizontal axis. Thus, a
4344: negative distance in a vertical position indicates that the side or axis
4345: specified in the rule is above the side or axis of the reference box.</p>
4346:
4347: <p>The distance can be followed by the <tt>UserSpecified</tt> keyword (even if
1.18 cvs 4348: the distance is nil and does not appear, the <tt>UserSpecified</tt> keyword
1.1 cvs 4349: can be used). It indicates that when the element to which the rule applies is
4350: being created, the editor will ask the user to specify the distance himself,
4351: using the mouse. In this case, the distance specified in the rule is a
4352: default distance which is suggested to the user but can be modified. The
1.18 cvs 4353: <tt>UserSpecified</tt> keyword can be used either in the vertical position
4354: rule, the horizontal position rule, or both.</p>
4355: <pre> VertPosition = Reference '.' HorizAxis [ Distance ] .
1.1 cvs 4356: HorizPosition = Reference '.' VertAxis [ Distance ] .
4357: Reference ='Enclosing' [ BoxTypeNot ] /
4358: 'Enclosed' [ BoxTypeNot ] /
4359: 'Previous' [ BoxTypeNot ] /
4360: 'Next' [ BoxTypeNot ] /
4361: 'Referred' [ BoxTypeNot ] /
4362: 'Creator' /
4363: 'Root' /
4364: '*' /
4365: BoxOrType .
4366: BoxOrType = BoxID /
4367: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 4368: 'AnyElem' / 'AnyBox' /
4369: 'ElemWithAttr' AttrID .
1.18 cvs 4370: BoxTypeNot = [ 'NOT' ] BoxOrType .</pre>
1.30 cvs 4371:
1.18 cvs 4372: <blockquote class="example">
1.30 cvs 4373: <p><strong>Example:</strong></p>
4374:
4375: <p>If a <a name="expos1">report</a> is defined by the following structure
4376: schema:</p>
4377: <pre>Report = BEGIN
1.6 cvs 4378: Title = Text;
4379: Summary = Text;
4380: Keywords = Text;
4381: ...
1.18 cvs 4382: END;</pre>
1.30 cvs 4383:
4384: <p>then the presentation schema could contain the rules:</p>
4385: <pre>Report : BEGIN
1.6 cvs 4386: VertPos : Top = Enclosing . Top;
4387: HorizPos : Left = Enclosing . Left;
4388: ...
1.18 cvs 4389: END;</pre>
1.30 cvs 4390:
4391: <p>These rules place the <a name="reportexample">report</a> in the upper
4392: left corner of the enclosing box, which is the window in which the document
4393: is being edited.</p>
4394: <pre>Title : BEGIN
1.6 cvs 4395: VertPos : Top = Enclosing . Top + 1;
4396: HorizPos : VMiddle = Enclosing . VMiddle;
4397: ...
1.18 cvs 4398: END;</pre>
1.30 cvs 4399:
4400: <p>The top of the title is one line (a line has the height of the characters
4401: of the title) from the top of the report, which is also the top of the
4402: editing window. The title is centered horizontally in the window (see <a
4403: href="#posdim">figure</a>).</p>
4404: <pre>Summary : BEGIN
1.1 cvs 4405: VertPos : Top = Title . Bottom + 1.5;
4406: HorizPos : Left = Enclosing . Left + 2 cm;
4407: ...
1.18 cvs 4408: END;</pre>
1.30 cvs 4409:
4410: <p>The top of the summary is place a line and a half below the bottom of the
4411: title and is shifted two centimeters from the side of the window.</p>
1.18 cvs 4412: </blockquote>
1.30 cvs 4413:
1.18 cvs 4414: <blockquote class="example">
1.30 cvs 4415: <p><strong>Example:</strong></p>
4416:
4417: <p>Suppose there is a <a name="expos2">Design</a> logical structure which
4418: contains graphical elements:</p>
4419: <pre>Design = LIST OF (ElemGraph = GRAPHICS);</pre>
4420:
4421: <p>The following rules allow the user to freely choose the position of each
4422: element when it is created:</p>
4423: <pre>ElemGraph =
1.1 cvs 4424: BEGIN
4425: VertPos : Top = Enclosing . Top + 1 cm UserSpecified;
4426: HorizPos: Left = Enclosing . Left UserSpecified;
4427: ...
1.18 cvs 4428: END;</pre>
1.30 cvs 4429:
4430: <p>Thus, when a graphical element is created, its default placement is at
4431: the left of the window and 1 cm from the top, but the user can move it
4432: immediately, simply by moving the mouse.</p>
1.18 cvs 4433: </blockquote>
4434: </div>
1.1 cvs 4435:
1.18 cvs 4436: <div class="subsection">
1.30 cvs 4437: <h3><a name="sectc4219">Box extents</a></h3>
1.1 cvs 4438:
1.30 cvs 4439: <p>The extents (height and width) of each box are defined by the two rules
1.18 cvs 4440: <tt>Height</tt> and <tt>Width</tt>. There are three types of extents: fixed,
4441: relative, and elastic.</p>
1.1 cvs 4442:
1.18 cvs 4443: <div class="subsubsection">
1.30 cvs 4444: <h4><a name="sectd42191">Fixed extents</a></h4>
1.1 cvs 4445:
1.30 cvs 4446: <p>A fixed dimension sets the height or width of the box independently of all
1.18 cvs 4447: other boxes. It is expressed in <a href="#sectc4217">distance units</a>. The
4448: extent can be followed by the <tt>UserSpecified</tt> keyword which indicates
1.1 cvs 4449: that when the element to which the rule applies is being created, the editor
4450: will ask the user to specify the extent himself, using the mouse. In this
4451: case, the extent specified in the rule is a default extent which is suggested
1.18 cvs 4452: to the user but can be modified. The <tt>UserSpecified</tt> keyword can be
4453: used either in the <tt>Height</tt> rule, the <tt>Width</tt> rule, or both.</p>
1.30 cvs 4454:
4455: <p>A fixed extent rule can be ended by the <tt>Min</tt> keyword, which
4456: signifies that the indicated value is a minimum, and that, if the contents of
4457: the box require it, a larger extent is possible.</p>
1.18 cvs 4458: <pre> 'Height' ':' Dimension
1.1 cvs 4459: 'Width' ':' Dimension
4460: Dimension = AbsDist [ 'UserSpecified' ] [ 'Min' ] /
1.18 cvs 4461: ...</pre>
1.30 cvs 4462:
1.18 cvs 4463: <blockquote class="example">
1.30 cvs 4464: <p><strong>Example:</strong></p>
4465:
4466: <p>Continuing with the <a href="#expos2">previous example</a>, it is
4467: possible to allow the user to choose the size of each graphical element as
4468: it is created:</p>
4469: <pre>ElemGraph : BEGIN
1.6 cvs 4470: Width : 2 cm UserSpecified;
1.1 cvs 4471: Height : 1 cm UserSpecified;
4472: ...
1.18 cvs 4473: END;</pre>
1.30 cvs 4474:
4475: <p>Thus, when a graphical element is create, it is drawn by default with a
4476: width of 2 cm and a height of 1 cm, but the user is free to resize it
4477: immediately with the mouse.</p>
4478: <pre>Summary : BEGIN
1.1 cvs 4479: Height : 5 cm Min;
4480: ...
4481: END;
4482: Keywords : BEGIN
4483: VertPos : Top = Summary . Bottom;
4484: ...
1.18 cvs 4485: END;</pre>
4486: </blockquote>
4487: </div>
1.1 cvs 4488:
1.18 cvs 4489: <div class="subsubsection">
1.30 cvs 4490: <h4><a name="sectd42192">Relative extents</a></h4>
4491:
4492: <p>A relative extent determines the extent as a function of the extent of
4493: another box, just as a relative position places a box in relation to another.
4494: The reference box in an extent rule is designated using the same syntax as is
4495: used in a relative position rule. It is followed by a period and a
4496: <tt>Height</tt> or <tt>Width</tt> keyword, depending on the extent being
4497: referred to. Next comes the relation between the extent being defined and the
4498: extent of the reference box. This relation can be either a percentage or a
4499: difference.</p>
1.1 cvs 4500:
1.30 cvs 4501: <p>A percentage is indicated by a star (the multiplication symbol) followed by
1.1 cvs 4502: the numeric percentage value (which may be greater than or less than 100) and
4503: the percent (`%') character. A difference is simply indicated by a signed
1.18 cvs 4504: difference.</p>
1.30 cvs 4505:
4506: <p>If the rule appears in the presentation rules of a numeric attribute, the
1.1 cvs 4507: percentage value can be replaced by the name of the attribute. This attribute
1.18 cvs 4508: is then used as a percentage. The attribute can also be used as part of a <a
4509: href="#distance">difference</a>.</p>
1.30 cvs 4510:
4511: <p>Just as with a fixed extent, a relative extent rule can end with the
1.18 cvs 4512: <tt>Min</tt> keyword, which signifies that the extent is a minimum and that,
4513: if the contents of the box require it, a larger extent is possible.</p>
1.30 cvs 4514:
4515: <p>A special case of relative extent rules is:</p>
1.18 cvs 4516: <pre>Height : Enclosed . Height;</pre>
1.30 cvs 4517:
4518: <p>or</p>
1.18 cvs 4519: <pre>Width : Enclosed . Width;</pre>
1.30 cvs 4520:
4521: <p>which specifies that the box has a height (or width) such that it encloses
4522: all the boxes which it contains, excluding boxes having a rule
4523: <tt>VertOverflow: Yes;</tt> or <tt>HorizOverflow: Yes;</tt>.</p>
4524:
4525: <p><strong>Note:</strong> character strings (type <tt>TEXT_UNIT</tt>)
4526: generally must use the sum of the widths of the characters which compose them
4527: as their width, which is expressed by the rule:</p>
1.18 cvs 4528: <pre>TEXT_UNIT :
4529: Width : Enclosed . Width;</pre>
1.30 cvs 4530:
4531: <p>If this rule is not the default <tt>Width</tt> rule, it must be given
1.18 cvs 4532: explicitly in the <tt>RULES</tt> section which defines the presentation rules
4533: of the logical elements.</p>
4534: <pre> 'Height' ':' Extent
1.1 cvs 4535: 'Width' ':' Extent
4536: Extent = Reference '.' HeightWidth [ Relation ]
4537: [ 'Min' ] / ...
4538: HeightWidth ='Height' / 'Width' .
4539: Relation ='*' ExtentAttr '%' / Distance .
4540: ExtentAttr = ExtentVal / AttrID .
1.18 cvs 4541: ExtentVal = NUMBER .</pre>
1.30 cvs 4542:
1.18 cvs 4543: <blockquote class="example">
1.30 cvs 4544: <p><strong>Example:</strong></p>
4545:
4546: <p>Completing the <a href="#expos1">above example</a>, it is possible to
4547: specify that the report takes its width from the editing window and its
4548: height from the size of its contents (this can obviously be greater than
4549: that of the window):</p>
4550: <pre>Report : BEGIN
1.1 cvs 4551: Width : Enclosing . Width;
4552: Height : Enclosed . Height;
4553: ...
1.18 cvs 4554: END;</pre>
1.30 cvs 4555:
4556: <p>Then, the following rules make the title occupy 60% of the width of the
4557: report (which is that of the window) and is broken into centered lines of
4558: this width (see the <a href="#sectc4222"><tt>Line</tt> rule</a>).</p>
4559: <pre>Title : BEGIN
1.1 cvs 4560: Width : Enclosing . Width * 60%;
4561: Height : Enclosed . Height;
4562: Line;
4563: Adjust : VMiddle;
4564: ...
1.18 cvs 4565: END;</pre>
1.30 cvs 4566:
4567: <p>The summary occupy the entire width of the window, with the exception of
4568: a 2 cm margin reserved by the horizontal position rule:</p>
4569: <pre>Summary : BEGIN
1.1 cvs 4570: Width : Enclosing . Width - 2 cm;
4571: Height : Enclosed . Height;
4572: ...
1.18 cvs 4573: END;</pre>
4574:
1.30 cvs 4575: <p>This set of rules, plus the <a href="#reportexample">position rules given
4576: above</a>, produce the layout of boxes shown in the following<a
4577: href="#posdim">figure</a>.</p>
4578:
4579: <div class="figure">
4580: <hr>
4581: <pre>-------------------------------------------------------------
1.1 cvs 4582: | Window and Report ^ |
4583: | | 1 line |
4584: | v |
4585: | ------------------------------------- |
4586: | | | |
4587: : 20% : Title : 20% :
1.30 cvs 4588: :<--------->: :<--------->:
1.1 cvs 4589: : : 60% : :
1.30 cvs 4590: : :<--------------------------------->: :
1.1 cvs 4591: | | | |
4592: | ------------------------------------- |
4593: | ^ |
4594: | | 1.5 line |
4595: | | |
4596: | v |
4597: | ---------------------------------------------------|
4598: | 2 cm | |
1.30 cvs 4599: |<------>| Summary |
1.18 cvs 4600: : : :</pre>
1.19 cvs 4601:
1.30 cvs 4602: <p align="center"><em><a name="posdim">Box position and
4603: extent</a><em></em></em></p>
4604: <hr>
4605: </div>
1.18 cvs 4606: </blockquote>
4607: </div>
1.1 cvs 4608:
1.18 cvs 4609: <div class="subsubsection">
1.30 cvs 4610: <h4><a name="sectd42193">Elastic extents</a></h4>
1.1 cvs 4611:
1.30 cvs 4612: <p>The last type of extent is the elastic extent. Either one or both extents
4613: can be elastic. A box has an elastic extent when two opposite sides are
4614: linked by distance constraints to two sides or axes of other boxes.</p>
4615:
4616: <p>One of the sides of the elastic box is linked by a position rule
1.18 cvs 4617: (<tt>VertPos</tt> or <tt>HorizPos</tt>) to a neighboring box. The other side
4618: is link to another box by a <tt>Height</tt> or <tt>Width</tt> rule, which
1.1 cvs 4619: takes the same form as the position rule. For the elastic box itself, the
4620: notions of sides (left or right, top or bottom) are fuzzy, since the movement
4621: of either one of the two reference boxes can, for example, make the left side
4622: of the elastic box move to the right of its right side. This is not
4623: important. The only requirement is that the two sides of the elastic box used
1.18 cvs 4624: in the position and extent rule are opposite sides of the box.</p>
4625: <pre> 'Height' ':' Extent
1.6 cvs 4626: 'Width' ':' Extent
1.18 cvs 4627: Extent = HPos / VPos / ...</pre>
1.30 cvs 4628:
1.18 cvs 4629: <blockquote class="example">
1.30 cvs 4630: <p><strong>Example:</strong></p>
4631:
4632: <p>Suppose we want to draw an elastic arrow or line between the middle of
4633: the bottom side of box A and the upper left corner of box B. To do this, we
4634: would define a graphics box whose upper left corner coincides with the
4635: middle of the bottom side of A (a position rule) and whose lower right
4636: corner coincides with with the upper left corner of B (dimension rules):</p>
4637: <pre>LinkedBox :
1.1 cvs 4638: BEGIN
1.6 cvs 4639: VertPos : Top = A .Bottom;
1.1 cvs 4640: HorizPos : Left = A . VMiddle;
1.6 cvs 4641: Height : Bottom = B . Top;
4642: Width : Right = B . Left;
1.18 cvs 4643: END;</pre>
4644: </blockquote>
1.30 cvs 4645:
1.18 cvs 4646: <blockquote class="example">
1.30 cvs 4647: <p><strong>Example:</strong></p>
4648:
4649: <p>The element SectionTitle creates a presentation box called SectionNum
4650: which contains the number of the section. Suppose we want to align the
4651: SectionNum and SectionTitle horizontally, have the SectionNum take its width
4652: from its contents (the section number), have the SectionTitle box begin 0.5
4653: cm to the right of the SectionNum box and end at the right edge of its
4654: enclosing box. This would make the SectionTitle box elastic, since its width
4655: is defined by the position of its left and right sides. The following rules
4656: produce this effect:</p>
4657: <pre>SectionNum :
1.1 cvs 4658: BEGIN
4659: HorizPos : Left = Enclosing . Left;
4660: Width : Enclosed . Width;
4661: ...
4662: END;
4663:
4664: SectionTitle :
4665: BEGIN
4666: HorizPos : Left = SectionNum . Right + 0.5 cm;
4667: Width : Right = Enclosing . Right;
4668: ...
1.18 cvs 4669: END;</pre>
4670: </blockquote>
4671: </div>
4672: </div>
1.1 cvs 4673:
1.18 cvs 4674: <div class="subsection">
1.30 cvs 4675: <h3><a name="sectc4220">Overflow</a></h3>
1.1 cvs 4676:
1.30 cvs 4677: <p>A boxes corresponding to a structural element normally contain all boxes
1.1 cvs 4678: corresponding to the elements of its subtree. However, in some cases, it
4679: could be necessary to allow a box to jut out from its parent box. Two
4680: presentation rules indicate that such an overflow is allowed, one for
1.18 cvs 4681: horizontal overflow, one for vertical overflow.</p>
1.30 cvs 4682:
4683: <p>Each of these rules is expressed by a keyword followed by a colon and the
1.18 cvs 4684: keyword <tt>Yes</tt> or <tt>No</tt>.</p>
4685: <pre> 'VertOverflow' ':' Boolean /
1.1 cvs 4686: 'HorizOverflow' ':' Boolean .
1.18 cvs 4687: Boolean = 'Yes' / 'No' .</pre>
4688: </div>
1.1 cvs 4689:
1.30 cvs 4690: <p>@@@@@ ******</p>
4691:
1.26 cvs 4692: <p>Explain Margin, Padding and Border. Refer to CSS2.</p>
4693: <pre> 'MarginTop' ':' MarginWidth /
4694: 'MarginRight' ':' MarginWidth /
4695: 'MarginBottom' ':' MarginWidth /
4696: 'MarginLeft' ':' MarginWidth /
4697: 'PaddingTop' ':' PaddingWidth /
4698: 'PaddingRight' ':' PaddingWidth /
4699: 'PaddingBottom' ':' PaddingWidth /
4700: 'PaddingLeft' ':' PaddingWidth /
4701: 'BorderTopWidth' ':' BorderWidth /
4702: 'BorderRightWidth' ':' BorderWidth /
4703: 'BorderBottomWidth' ':' BorderWidth /
4704: 'BorderLeftWidth' ':' BorderWidth /
4705: 'BorderTopColor' ':' BorderColor /
4706: 'BorderRightColor' ':' BorderColor /
4707: 'BorderBottomColor' ':' BorderColor /
4708: 'BorderLeftColor' ':' BorderColor /
4709: 'BorderTopStyle' ':' BorderStyle /
4710: 'BorderRightStyle' ':' BorderStyle /
4711: 'BorderBottomStyle' ':' BorderStyle /
4712: 'BorderLeftStyle' ':' BorderStyle .
4713:
4714: MarginWidth = InheritParent / 'Auto' / Distance .
4715: PaddingWidth = InheritParent / Distance .
4716: BorderWidth = InheritParent / 'Thin' / 'Medium' / 'Thick' / Distance .
4717: BorderColor = InheritParent / 'Transparent' / 'Foreground' /
4718: ColorName .
4719: BorderStyle = InheritParent /
4720: 'None' / 'Hidden' / 'Dotted' / 'Dashed' / 'Solid' /
4721: 'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
1.27 cvs 4722: InheritParent = 'Enclosing' '=' / 'Creator' '=' .
1.26 cvs 4723: ColorName = NAME .</pre>
1.30 cvs 4724:
4725: <p>@@@@@ ******</p>
1.26 cvs 4726:
1.18 cvs 4727: <div class="subsection">
1.30 cvs 4728: <h3><a name="sectc4221">Inheritance</a></h3>
1.1 cvs 4729:
1.30 cvs 4730: <p>A presentation parameter can be defined by reference to the same parameter
4731: of another box in the tree of boxes. These structural links are expressed by
1.1 cvs 4732: kinship. The reference box can be that of the element immediately above in
1.18 cvs 4733: the structure (<tt>Enclosing</tt>), two levels above (<tt>GrandFather</tt>),
4734: immediately below (<tt>Enclosed</tt>) or immediately before
4735: (<tt>Previous</tt>). In the case of a presentation box, and only in that
1.1 cvs 4736: case, the reference box may be the element which created the presentation box
1.18 cvs 4737: (<tt>Creator</tt>).</p>
1.30 cvs 4738:
4739: <p>Kinship is expressed in terms of the logical structure of the document and
4740: not in terms of the tree of boxes. The presentation box cannot transmit any
4741: of their parameters by inheritance; only structured element boxes can do so.
4742: As an example, consider an element B which follows an element A in the logical
1.1 cvs 4743: structure. The element B creates a presentation box P in front of itself,
1.18 cvs 4744: using the <tt>CreateBefore</tt> rule (see the <a href="#sectc4232">creation
4745: rules</a>). If element B's box inherits its character style using the
4746: <tt>Previous</tt> kinship operation, it gets its character style from A's box,
1.1 cvs 4747: not from P's box. Inheritance works differently for positions and extents,
1.18 cvs 4748: which can refer to presentation boxes.</p>
1.30 cvs 4749:
4750: <p>The inherited parameter value can be the same as that of the reference box.
1.1 cvs 4751: This is indicated by an equals sign. However, for numeric parameters, a
4752: different value can be obtained by adding or subtracting a number from the
4753: reference box's parameter value. Addition is indicated by a plus sign before
4754: the number, while subtraction is specified with a minus sign. The value of a
4755: parameter can also be given a maximum (if the sign is a plus) or minimum (if
1.18 cvs 4756: the sign is a minus).</p>
1.30 cvs 4757:
4758: <p>If the rule is being applied to a numeric attribute, the number to add or
1.1 cvs 4759: subtract can be replaced by the attribute name. The value of a maximum or
4760: minimum may also be replaced by an attribute name. In these cases, the value
1.18 cvs 4761: of the attribute is used.</p>
4762: <pre> Inheritance = Kinship InheritedValue .
1.6 cvs 4763: Kinship ='Enclosing' / 'GrandFather' / 'Enclosed' /
4764: 'Previous' / 'Creator' .
1.1 cvs 4765: InheritedValue ='+' PosIntAttr [ 'Max' maximumA ] /
1.6 cvs 4766: '-' NegIntAttr [ 'Min' minimumA ] /
4767: '=' .
4768: PosIntAttr = PosInt / AttrID .
4769: PosInt = NUMBER .
4770: NegIntAttr = NegInt / AttrID .
4771: NegInt = NUMBER .
4772: maximumA = maximum / AttrID .
4773: maximum = NUMBER .
4774: minimumA = minimum / AttrID .
1.18 cvs 4775: minimum = NUMBER .</pre>
1.30 cvs 4776:
4777: <p>The parameters which can be obtained by inheritance are justification,
1.1 cvs 4778: hyphenation, interline spacing, character font (font family), font style, font
4779: size, visibility, indentation, underlining, alignment of text, stacking order
4780: of objects, the style and thickness of lines, fill pattern and the colors of
1.18 cvs 4781: lines and characters.</p>
4782: </div>
1.1 cvs 4783:
1.18 cvs 4784: <div class="subsection">
1.30 cvs 4785: <h3><a name="sectc4222">Line breaking</a></h3>
1.1 cvs 4786:
1.30 cvs 4787: <p>The <tt>Line</tt> rule specifies that the contents of the box should be
4788: broken into lines: the boxes included in the box to which this rule is
4789: attached are displayed one after the other, from left to right, with their
4790: horizontal reference axes aligned so that they form a series of lines. The
4791: length of these lines is equal to the width of the box to which the
4792: <tt>Line</tt> rule is attached.</p>
4793:
4794: <p>When an included box overflows the current line, it is either carried
4795: forward to the next line, cur, or left the way it is. The <a
1.18 cvs 4796: href="#sectc4223"><tt>LineBreak</tt> rule</a> is used to allow or prevent the
1.1 cvs 4797: breaking of included boxes. If the included box is not breakable but is
4798: longer than the space remaining on the line, it is left as is. When a
4799: character string box is breakable, the line is broken between words or, if
1.18 cvs 4800: necessary, by <a href="#sectd42225">hyphenating a word</a>. When a compound
4801: box is breakable, the box is transparent in regard to line breaking. The boxes
4802: included in the compound box are treated just like included boxes which have
4803: the <tt>LineBreak</tt> rule. Thus, it is possible to traverse a complete
4804: subtree of boxes to line break the text leaves of a complex structure.</p>
1.30 cvs 4805:
4806: <p>The relative position rules of the included boxes are ignored, since the
4807: boxes will be placed according to the line breaking rules.</p>
4808:
4809: <p>The <tt>Line</tt> rule does not have a parameter. The characteristics of
4810: the lines that will be constructed are determined by the <tt>LineSpacing</tt>,
1.18 cvs 4811: <tt>Indent</tt>, <tt>Adjust</tt>, <tt>Justify</tt>, and <tt>Hyphenate</tt>
4812: rules. Moreover, the <a href="#insectd42226"><tt>Inline</tt> rule</a> permits
4813: the exclusion of certain elements from the line breaking process.</p>
1.30 cvs 4814:
4815: <p>When the <tt>Line</tt> rule appears in the rules sequence of a non-primary
1.18 cvs 4816: view, it applies only to that view, but when the <tt>Line</tt> rule appears in
1.1 cvs 4817: the rules sequence of the primary view, it also applies to the other views by
1.18 cvs 4818: default, except for those views which explicitly invoke the <tt>NoLine</tt>
4819: rule. Thus, the <tt>NoLine</tt> rule can be used in a non-primary view to
4820: override the primary view's <tt>Line</tt> rule. The <tt>NoLine</tt> rule must
4821: not be used with the primary view because the absence of the <tt>Line</tt>
4822: rule has the same effect. Like the <tt>Line</tt> rule, the <tt>NoLine</tt>
4823: rule does not take any parameters.</p>
4824: <pre> 'Line'
4825: 'NoLine'</pre>
4826:
4827: <div class="subsubsection">
1.30 cvs 4828: <h4><a name="sectd42221">Line spacing</a></h4>
1.18 cvs 4829:
1.30 cvs 4830: <p>The <tt>LineSpacing</tt> rule defines the line spacing to be used in the
4831: line breaking process. The line spacing is the distance between the baselines
1.1 cvs 4832: (horizontal reference axis) of the successive lines produced by the
1.18 cvs 4833: <tt>Line</tt> rule. The value of the line spacing can be specified as a
4834: constant or by inheritance. It is expressed in any of the available <a
4835: href="#sectc4217">distance units</a>.</p>
1.30 cvs 4836:
4837: <p>Inheritance allows the value to be obtained from a relative in the
4838: structure tree, either without change (an equals sign appears after the
4839: inheritance keyword), with a positive difference (a plus sign), or a negative
4840: difference (a minus sign). When the rule uses a difference, the value of the
4841: difference follows the sign and is expressed as a <a
4842: href="#sectc4217">distance</a>.</p>
1.18 cvs 4843: <pre> 'LineSpacing' ':' DistOrInherit
1.6 cvs 4844: DistOrInherit = Kinship InheritedDist / Distance .
1.18 cvs 4845: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .</pre>
1.30 cvs 4846:
4847: <p>When the line spacing value (or its difference from another element) is
1.1 cvs 4848: expressed in relative units, it changes with the size of the characters. Thus,
4849: when a larger font is chosen for a part of the document, the line spacing of
4850: that part expands proportionally. In contrast, when the line spacing value is
4851: expressed in absolute units (centimeters, inches, typographer's points), it is
4852: independent of the characters, which permits the maintenance of a consistent
4853: line spacing, whatever the character font. Either approach can be taken,
1.18 cvs 4854: depending on the desired effect.</p>
4855: </div>
1.1 cvs 4856:
1.18 cvs 4857: <div class="subsubsection">
1.30 cvs 4858: <h4><a name="sectd42222">First line indentation</a></h4>
1.1 cvs 4859:
1.30 cvs 4860: <p>The <tt>Indent</tt> rule is used to specify the indentation of the first
4861: line of the elements broken into lines by the <tt>Line</tt> function. The
1.1 cvs 4862: indentation determines how far the first line of the element is shifted with
4863: respect to the other lines of the same element. It can be specified as a
4864: constant or by inheritance. The constant value is a positive integer (shifted
4865: to the right; the sign is optional), a negative integer (shifted to the left)
1.18 cvs 4866: or zero (no shift). All available <a href="#sectc4217">units</a> can be
4867: used.</p>
1.30 cvs 4868:
4869: <p>Indentation can be defined for any box, regardless of whether the box is
4870: line broken, and transmitted by inheritance to elements that are line broken.
4871: The size of the indentation is specified in the same manner as the <a
1.18 cvs 4872: href="#sectd42221">line spacing</a>.</p>
4873: <pre> 'Indent' ':' DistOrInherit</pre>
4874: </div>
1.1 cvs 4875:
1.18 cvs 4876: <div class="subsubsection">
1.30 cvs 4877: <h4><a name="sectd42223">Alignment</a></h4>
1.1 cvs 4878:
1.30 cvs 4879: <p>The alignment style of the lines constructed during line breaking is
4880: defined by the <tt>Adjust</tt> rule. The alignment value can be a constant or
1.18 cvs 4881: inherited. A constant value is specified by a keyword:</p>
4882: <ul>
1.30 cvs 4883: <li><tt>Left</tt>: at the left edge,</li>
4884: <li><tt>Right</tt>: at the right edge,</li>
4885: <li><tt>VMiddle</tt>: centered</li>
4886: <li><tt>LeftWithDots</tt>: at the left edge with a dotted line filling out
4887: the last line up to the right edge of the line breaking box.</li>
1.18 cvs 4888: </ul>
1.30 cvs 4889:
4890: <p>An inherited value can only be the same as that of the reference box and is
1.18 cvs 4891: specified by a kinship keyword followed by an equals sign.</p>
4892: <pre> 'Adjust' ':' AlignOrInherit
1.1 cvs 4893: AlignOrInherit = Kinship '=' / Alignment .
4894: Alignment = 'Left' / 'Right' / 'VMiddle' /
1.18 cvs 4895: 'LeftWithDots' .</pre>
4896: </div>
1.1 cvs 4897:
1.18 cvs 4898: <div class="subsubsection">
1.30 cvs 4899: <h4><a name="sectd42224">Justification</a></h4>
1.1 cvs 4900:
1.30 cvs 4901: <p>The <tt>Justify</tt> rule indicates whether the lines contained in the box
4902: and produced by a <tt>Line</tt> rule should be extended horizontally to occupy
4903: the entire width of their enclosing box. The first and last lines are treated
1.1 cvs 4904: specially: the position of the beginning of the first line is fixed by the
1.18 cvs 4905: <tt>Indent</tt> rule and last line is not extended. The justification
1.1 cvs 4906: parameter defined by this rule takes a boolean value, which can be a constant
4907: or inherited. A constant boolean value is expressed by either the
1.18 cvs 4908: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 4909: same as that of the reference box and is specified by a kinship keyword
1.18 cvs 4910: followed by an equals sign.</p>
4911: <pre> 'Justify' ':' BoolInherit
1.1 cvs 4912: BoolInherit = Boolean / Kinship '=' .
1.18 cvs 4913: Boolean ='Yes' / 'No' .</pre>
1.30 cvs 4914:
4915: <p>When the lines are justified, the alignment parameter specified in the
1.18 cvs 4916: <tt>Adjust</tt> rule has no influence, other than on the last line produced.
1.1 cvs 4917: This occurs because, when the other are extended to the limits of the box, the
1.18 cvs 4918: alignment style is no longer perceptible.</p>
1.30 cvs 4919:
1.18 cvs 4920: <blockquote class="example">
1.30 cvs 4921: <p><strong>Example:</strong></p>
4922:
4923: <p>An important use of inheritance is to vary the characteristics of lines
4924: for an element type (for example, Paragraph) according to the enclosing
4925: environment (for example, Summary or Section), and thus obtain different
4926: line breaking styles for the same elements when they appear in different
4927: environments. The following rules specify that paragraphs inherit their
4928: alignment, justification, and line spacing:</p>
4929: <pre>Paragraph :
1.1 cvs 4930: BEGIN
4931: Justify : Enclosing = ;
4932: LineSpacing : Enclosing = ;
4933: Adjust : Enclosing =;
4934: Line;
1.18 cvs 4935: END;</pre>
1.30 cvs 4936:
4937: <p>If the alignment, justification, and line spacing of the Section and
4938: Summary elements is fixed:</p>
4939: <pre>Section :
1.1 cvs 4940: BEGIN
4941: Adjust : Left;
4942: Justify : Yes;
4943: LineSpacing : 1;
4944: END;
4945: Summary :
4946: BEGIN
4947: Adjust : VMiddle;
4948: Justify : No;
4949: LineSpacing : 1.3;
1.18 cvs 4950: END;</pre>
1.30 cvs 4951:
4952: <p>then the paragraphs appearing in sections are justified with a simple
4953: line spacing while those appearing in summaries are centered and not
4954: justified and have a larger line spacing. These are nevertheless the very
4955: same type of paragraph defined in the logical structure schema.</p>
1.18 cvs 4956: </blockquote>
4957: </div>
4958:
4959: <div class="subsubsection">
1.30 cvs 4960: <h4><a name="sectd42225">Hyphenation</a></h4>
1.18 cvs 4961:
1.30 cvs 4962: <p>The <tt>Hyphenate</tt> rule indicates whether or not words should be broken
4963: by hyphenation at the end of lines. It affects the lines produced by the
1.18 cvs 4964: <tt>Line</tt> rule and contained in the box carrying the <tt>Hyphenate</tt>
4965: rule.</p>
1.30 cvs 4966:
4967: <p>The hyphenation parameter takes a boolean value, which can be either
4968: constant or inherited. A constant boolean value is expressed by either the
1.18 cvs 4969: <tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
1.1 cvs 4970: same as that of the reference box and is specified by a kinship keyword
1.18 cvs 4971: followed by an equals sign.</p>
4972: <pre> 'Hyphenate' ':' BoolInherit
1.1 cvs 4973: BoolInherit = Boolean / Kinship '=' .
1.18 cvs 4974: Boolean = 'Yes' / 'No' .</pre>
4975: </div>
4976:
4977: <div class="subsubsection">
1.30 cvs 4978: <h4><a name="sectd42226">Avoiding line breaking</a></h4>
1.18 cvs 4979:
1.30 cvs 4980: <p>The <tt>InLine</tt> rule is used to specify that a box that would otherwise
1.18 cvs 4981: participate in line breaking asked for by the <tt>Line</tt> rule of an
1.1 cvs 4982: enclosing box, instead avoids the line breaking process and positions itself
1.18 cvs 4983: according to the <tt>HorizPos</tt> and <tt>VertPos</tt> rules that apply to
4984: it. When the <tt>InLine</tt> rule applies to a box which would not be line
4985: broken, it has no effect.</p>
1.30 cvs 4986:
4987: <p>The rule is expressed by the <tt>InLine</tt> keyword followed by a colon
4988: and the keyword <tt>Yes</tt>, if the box should participate in line breaking,
4989: or the keyword <tt>No</tt>, if it should not. This is the only form possible:
1.1 cvs 4990: this rule cannot be inherited. Moreover, it can only appear in the rules of
4991: the primary view and applies to all views defined in the presentation
1.18 cvs 4992: schema.</p>
4993: <pre> 'InLine' ':' Boolean .
4994: Boolean = 'Yes' / 'No' .</pre>
1.30 cvs 4995:
1.18 cvs 4996: <blockquote class="example">
1.30 cvs 4997: <p><strong>Example:</strong></p>
4998:
4999: <p>Suppose the structure schema defines a logical attribute called
5000: <tt>New</tt> which is used to identify the passages in a document which were
5001: recently modified. It would be nice to have the presentation schema make a
5002: bar appear in the left margin next to each passage having the <tt>New</tt>
5003: attribute. A new passage can be an entire element, such as a paragraph or
5004: section, or it can be some words in the middle of a paragraph. To produce
5005: the desired effect, the <tt>New</tt> attribute is given a creation rule
5006: which generates a <tt>VerticalBar</tt> presentation box.</p>
5007:
5008: <p>When the <tt>New</tt> attribute is attached to a character string which
5009: is inside a line broken element (inside a paragraph, for example), the bar
5010: is one of the elements which participates in line breaking and it is placed
5011: normally in the current line, at the end of the character string which has
5012: the attribute. To avoid this, the <tt>InLine</tt> rule is used in the
5013: following way:</p>
5014: <pre>BOXES
1.1 cvs 5015: VerticalBar:
5016: BEGIN
5017: Content: Graphics 'l';
5018: HorizPos: Left = Root . Left;
5019: VertPos: Top = Creator . Top;
5020: Height: Bottom = Creator . Bottom;
5021: Width: 1 pt;
5022: InLine: No;
5023: ...
5024: END;
5025: ...
5026: ATTRIBUTES
5027: Nouveau:
5028: BEGIN
5029: CreateAfter(VerticalBar);
1.18 cvs 5030: END;</pre>
5031: </blockquote>
5032: </div>
5033: </div>
1.1 cvs 5034:
1.18 cvs 5035: <div class="subsection">
1.30 cvs 5036: <h3><a name="sectc4223">Page breaking and line breaking conditions</a></h3>
1.1 cvs 5037:
1.30 cvs 5038: <p>Pages are constructed by the editor in accordance with the model specified
5039: by a <a href="#sectc4233"><tt>Page</tt> rule</a>. The page model describes
5040: only the composition of the pages but does not give any rules for breaking
1.18 cvs 5041: different element types across pages. Now, it is possible that certain
5042: elements must not be cut by page breaks, while others can be cut anywhere. The
5043: <tt>PageBreak</tt>, <tt>NoBreak1</tt>, and <tt>NoBreak2</tt> rules are used to
5044: specify the conditions under which each element type can be cut.</p>
1.30 cvs 5045:
5046: <p>The <tt>PageBreak</tt> rule is used to indicate whether or not the box can
5047: be cut during the construction of pages. If cutting is authorized, the box
5048: can be cut, with one part appearing at the bottom of a page and the other part
1.1 cvs 5049: appearing at the top of the next page. The rule is formed by the
1.18 cvs 5050: <tt>PageBreak</tt> keyword followed by a colon and a constant boolean value
5051: (<tt>Yes</tt> or <tt>No</tt>). This is the only form possible: this rule
1.1 cvs 5052: cannot be inherited. Moreover, it can only appear in the rules of the primary
1.18 cvs 5053: view and applies to all views defined in the presentation schema.</p>
1.30 cvs 5054:
5055: <p>Whether objects can be cut by line breaks can be controlled in a similar
5056: way using the <tt>LineBreak</tt> rule. This rule allows the specification of
1.1 cvs 5057: whether or not the box can be cut during the construction of lines. If
5058: cutting is authorized, the box can be cut, with one part appearing at the end
5059: of a line and the other part appearing at the beginning of the next line. The
1.18 cvs 5060: rule is formed by the <tt>LineBreak</tt> keyword followed by a colon and a
5061: constant boolean value (<tt>Yes</tt> or <tt>No</tt>). This is the only form
1.1 cvs 5062: possible: this rule cannot be inherited. Moreover, it can only appear in the
5063: rules of the primary view and applies to all views defined in the presentation
1.18 cvs 5064: schema.</p>
5065: <pre> 'PageBreak' ':' Boolean .
1.1 cvs 5066: 'LineBreak' ':' Boolean .
1.18 cvs 5067: Boolean = 'Yes' / 'No' .</pre>
1.30 cvs 5068:
5069: <p>When a box can be cut by a page break, it is possible that a page break
5070: will fall an inappropriate spot, creating, for example, a widow or orphan, or
1.1 cvs 5071: separating the title of a section from the first paragraph of the section. The
1.18 cvs 5072: <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules are used to avoid this. They
5073: specify that the box of the element to which they apply cannot be cut within a
5074: certain zone at the top (<tt>NoBreak1</tt> rule) or at the bottom
5075: (<tt>NoBreak2</tt> rule). These two rules specify the height of the zones in
5076: which page breaks are prohibited.</p>
1.30 cvs 5077:
5078: <p>The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules give the height of the
5079: zone in which page breaking is prohibited. The height is given as a constant
5080: value using any of the <a href="#sectc4217">available units</a>, absolute or
1.18 cvs 5081: relative. The value may not be inherited.</p>
5082: <pre> 'NoBreak1' ':' AbsDist .
5083: 'NoBreak2' ':' AbsDist .</pre>
1.30 cvs 5084:
1.18 cvs 5085: <blockquote class="example">
1.30 cvs 5086: <p><strong>Example:</strong></p>
5087:
5088: <p>The following rules prevent widows and orphans in a paragraph:</p>
5089: <pre>Paragraph :
1.1 cvs 5090: BEGIN
5091: NoBreak1 : 2;
5092: NoBreak2 : 2;
1.18 cvs 5093: END;</pre>
1.30 cvs 5094:
5095: <p>This rule prevents a section title from becoming separated from the first
5096: paragraph of the section by prohibiting page breaks at the beginning of the
5097: section rule:</p>
5098: <pre>Section :
1.18 cvs 5099: NoBreak1 : 1.5 cm;</pre>
1.30 cvs 5100:
5101: <p>Finally, this rule prevents a figure from being page broken in any
5102: way:</p>
5103: <pre>Figure :
1.18 cvs 5104: PageBreak : No;</pre>
5105: </blockquote>
1.30 cvs 5106:
5107: <p>The Thot editor constructs the document images displayed on the screen
1.1 cvs 5108: dynamically. As the user moves in the document or makes the document scroll
5109: in a window, the editor constructs the image to be displayed in little bits,
5110: filling the gaps which are produced in the course of these operations. It
5111: stops filling in the image when an element reaches the edge of the window in
5112: which the gap appears. If the appearance of the document is complex, it is
5113: possible that the image in incomplete, even though the edge of the window was
5114: reached. For example, an element might need to be presented to the side of
5115: the last element displayed, but its image was not constructed. The user will
5116: not know whether the element is really absent or if its image has simply not
1.18 cvs 5117: been constructed.</p>
1.30 cvs 5118:
5119: <p>The <tt>Gather</tt> rule is used to remedy this problem. When the rule
1.18 cvs 5120: <tt>Gather : Yes;</tt> is associated with an element type, the image of such
5121: elements is constructed as a block by the editor: it is never split up.</p>
1.30 cvs 5122:
5123: <p>The <tt>Gather</tt> rule may not appear in the <a href="#sectc427">default
1.18 cvs 5124: rules</a>. Elements which do not have the <tt>Gather</tt> rule are considered
5125: susceptible to being split up during display. Thus, it is not necessary to
5126: use the <tt>Gather : No;</tt> form. This rule must be used prudently and only
5127: for those elements which truly need it. If used incorrectly, it can
5128: pointlessly increase the size of the image constructed by the editor and lead
5129: to excessive memory consumption by the editor.</p>
1.30 cvs 5130:
5131: <p>Like the <tt>PageBreak</tt> and <tt>LineBreak</tt> rules, the
5132: <tt>Gather</tt> rule can only appear in rules of the primary view and applies
5133: to all views defined in the presentation schema.</p>
1.18 cvs 5134: <pre> 'Gather' ':' Boolean .</pre>
5135: </div>
1.1 cvs 5136:
1.18 cvs 5137: <div class="subsection">
1.30 cvs 5138: <h3><a name="sectc4224">Visibility</a></h3>
1.1 cvs 5139:
1.30 cvs 5140: <p>The visibility parameter is used to control which elements should or should
1.1 cvs 5141: not be displayed, based on context. An element can have different
5142: visibilities in different views. If an element's visibility is zero for a
5143: view, that element is not displayed in that view and does not occupy any space
1.18 cvs 5144: (its extents are zero).</p>
1.30 cvs 5145:
5146: <p>Visibility takes non-negative integer values (positive or zero). If values
1.1 cvs 5147: greater than 1 are used, they allow the user to choose a degree of visibility
5148: and, thus, to see only those boxes whose visibility parameter exceeds a
5149: certain threshold. This gives the user control over the granularity of the
1.18 cvs 5150: displayed pictures.</p>
1.30 cvs 5151:
5152: <p>The visibility parameter can be defined as a constant or by inheritance. If
1.1 cvs 5153: defined by inheritance, it cannot be based on the value of the next or
1.18 cvs 5154: previous box. Visibility can only be inherited from above.</p>
1.30 cvs 5155:
5156: <p>If it is a numeric attribute's presentation rule, the visibility can be
1.1 cvs 5157: specified by the attribute's name, in which case the value of the attribute is
1.18 cvs 5158: used.</p>
5159: <pre> 'Visibility' ':' NumberInherit
1.1 cvs 5160: NumberInherit = Integer / AttrID / Inheritance .
1.18 cvs 5161: Integer = NUMBER .</pre>
1.30 cvs 5162:
1.18 cvs 5163: <blockquote class="example">
1.30 cvs 5164: <p><strong>Example:</strong></p>
5165:
5166: <p>Suppose that only <tt>Formula</tt> elements should be displayed in the
5167: <tt>MathView</tt> view. Then, the default rules should include:</p>
5168: <pre>DEFAULT
1.18 cvs 5169: IN MathView Visibility:0;</pre>
1.30 cvs 5170:
1.31 cvs 5171: <p>which makes all elements invisible in the <tt>MathView</tt> view.
1.30 cvs 5172: However, the <tt>Formula</tt> element also has a <tt>Visibility</tt>
5173: rule:</p>
5174: <pre>Formula :
1.18 cvs 5175: IN MathView Visibility:5;</pre>
1.30 cvs 5176:
5177: <p>which makes formulas, and only formulas, visible.</p>
1.18 cvs 5178: </blockquote>
5179: </div>
1.1 cvs 5180:
1.18 cvs 5181: <div class="subsection">
1.30 cvs 5182: <h3><a name="sectc4225">Character style parameters</a></h3>
1.1 cvs 5183:
1.30 cvs 5184: <p>Four parameters are used to determine which characters are used to display
1.18 cvs 5185: text. They are size, font, style, and underlining.</p>
1.1 cvs 5186:
1.18 cvs 5187: <div class="subsubsection">
1.30 cvs 5188: <h4><a name="sectd42251">Character size</a></h4>
5189:
5190: <p>The size parameter has two effects. First, it is used to specify the
5191: actual size and distance units for boxes defined in <a
5192: href="#sectc4217">relative units</a>. Second, it defines the size of the
5193: characters contained in the box.</p>
1.1 cvs 5194:
1.30 cvs 5195: <p>As a distance or length, the size can be expressed in abstract or absolute
1.1 cvs 5196: units. It can also be inherited. If it is not inherited, it is expressed
1.18 cvs 5197: simply as an integer followed by the <tt>pt</tt> keyword, which indicates that
5198: the size is expressed in typographer's points. The absence of the <tt>pt</tt>
1.1 cvs 5199: keyword indicates that it is in abstract units in which the value 1 represents
5200: the smallest size while the value 16 is the largest size. The relationship
5201: between these abstract sizes and the real character sizes is controlled by a
5202: table which can be modified statically or even dynamically during the
1.18 cvs 5203: execution of the Thot editor.</p>
1.30 cvs 5204:
5205: <p>If the <tt>Size</tt> rule is a numeric attribute's presentation rule, the
5206: value of the size parameter can be specified by the attribute's name, in which
5207: case the value of the attribute is used.</p>
5208:
5209: <p><strong>Note:</strong> the only unit available for defining an absolute
5210: size is the typographer's point. Centimeters and inches may not be used.</p>
5211:
5212: <p>If the size is inherited, the rule must specify the relative from which to
5213: inherit and any percentage or difference from that relative's value. A
5214: percentage is indicated by a <tt>*</tt> followed by the value of the
5215: percentage and a <tt>%</tt>. A difference can be expressed in either
5216: typographer's points or in abstract units and the maximum or minimum size can
5217: be specified, but without specifying the unit: it is the same as was specified
5218: for the difference.</p>
5219:
5220: <p>In a numeric attribute's presentation rule, the difference in size or the
1.22 cvs 5221: percentage can be indicated by the attribute's name instead of the numeric
5222: value, which means that the attribute's value should be used as the difference
5223: or percentage. The attribute can also be used as the minimum or maximum size
5224: for a difference.</p>
5225: <pre> 'Size' ':' SizeInherit
5226: SizeInherit = SizeAttr [ 'pt' ] /
5227: Kinship InheritedSize .
5228: InheritedSize ='+' SizeAttr [ 'pt' ]
5229: [ 'Max' MaxSizeAttr ] /
5230: '-' SizeAttr [ 'pt' ]
5231: [ 'Min' MinSizeAttr ] /
5232: '*' PercentSizeAttr '%' /
5233: '=' .
5234: SizeAttr = Size / AttrID .
5235: Size = NUMBER .
5236: MaxSizeAttr = MaxSize / AttrID .
5237: MaxSize = NUMBER .
5238: MinSizeAttr = MinSize / AttrID .
5239: MinSize = NUMBER .
5240: PercentSizeAttr = PercentSize / AttrID .
5241: PercentSize = NUMBER .</pre>
1.30 cvs 5242:
1.18 cvs 5243: <blockquote class="example">
1.30 cvs 5244: <p><strong>Example:</strong></p>
5245:
5246: <p>The rule</p>
5247: <pre>Size : Enclosing - 2 pt Min 7;</pre>
5248:
5249: <p>states that the character size is 2 points less than that of the
5250: enclosing box, but that it may not be less than 7 points, whatever the
5251: enclosing box's value.</p>
5252:
5253: <p>The following rules make the text of a report be displayed with
5254: medium-sized characters (for example, size 5), while the title is displayed
5255: with larger characters and the summary is displayed with smaller
5256: characters:</p>
5257: <pre>Report :
1.1 cvs 5258: Size : 5;
5259: Title :
5260: Size : Enclosing + 2;
5261: Summary :
1.18 cvs 5262: Size : Enclosing - 1;</pre>
1.30 cvs 5263:
5264: <p>Thus, the character sizes in the entire document can be changed by
5265: changing the size parameter of the Report element, while preserving the
5266: relationships between the sizes of the different elements.</p>
1.18 cvs 5267: </blockquote>
5268: </div>
5269:
5270: <div class="subsubsection">
1.30 cvs 5271: <h4><a name="sectd42252">Font and character style</a></h4>
1.18 cvs 5272:
1.30 cvs 5273: <p>The <tt>Font</tt> rule determines the font family to be used to display the
1.18 cvs 5274: characters contained in the box, while the <tt>Style</tt> rule determines
1.23 cvs 5275: their style and the <tt>Weight</tt> rule determines their weight. Thot
5276: recognizes three character fonts (Times, Helvetica, and Courier), three
5277: styles: Roman, Italics, and Oblique, and two weights: Normal and Bold.</p>
1.30 cvs 5278:
5279: <p>The font family, style and weight can be specified by a named constant or
5280: can be inherited. For the name of the font family only the first character is
5281: used.</p>
5282:
5283: <p>Only identical inheritance is allowed: the box takes the same font, style
5284: or weight as the box from which it inherits. This is indicated by an equals
1.23 cvs 5285: sign after the kinship specification.</p>
5286: <pre> 'Font' ':' NameInherit /
5287: 'Style' ':' StyleInherit /
5288: 'Weight' ':' WeightInherit /
5289:
5290: NameInherit = Kinship '=' / FontName .
5291: FontName = NAME .
5292: StyleInherit = Kinship '=' /
5293: 'Roman' / 'Italics' / 'Oblique' .
5294: WeightInherit = Kinship '=' /
5295: 'Normal' / 'Bold' .</pre>
1.30 cvs 5296:
1.18 cvs 5297: <blockquote class="example">
1.30 cvs 5298: <p><strong>Example:</strong></p>
5299:
5300: <p>To specify that the summary uses the font family of the rest of the
5301: document, but in the italic style, the following rules are used:</p>
5302: <pre>Summary :
1.1 cvs 5303: BEGIN
5304: Font : Enclosing =;
5305: Style : Italics;
1.18 cvs 5306: END;</pre>
5307: </blockquote>
5308: </div>
5309:
5310: <div class="subsubsection">
1.30 cvs 5311: <h4><a name="sectd42253">Underlining</a></h4>
1.18 cvs 5312:
1.30 cvs 5313: <p>The <tt>Underline</tt> rule is used to specify if the characters contained
5314: in a box should have lines drawn on or near them. There are four underlining
1.18 cvs 5315: styles: <tt>Underlined</tt>, <tt>Overlined</tt>, <tt>CrossedOut</tt>, and
5316: <tt>NoUnderline</tt>. The <tt>Thickness</tt> rule specifies the thickness of
5317: the line, <tt>Thin</tt> or <tt>Thick</tt>.</p>
1.30 cvs 5318:
5319: <p>As with font family and style, only identical inheritance is allowed: the
5320: box has the same underlining type as the box from which it inherits the value.
1.18 cvs 5321: This is indicated by an equals sign after the kinship specification.</p>
5322: <pre> 'Underline' ':' UnderLineInherit /
1.1 cvs 5323: 'Thickness' ':' ThicknessInherit /
5324:
5325: UnderLineInherit = Kinship '=' / 'NoUnderline' /
5326: 'Underlined' /
5327: 'Overlined' / 'CrossedOut' .
1.18 cvs 5328: ThicknessInherit = Kinship '=' / 'Thick' / 'Thin' .</pre>
5329: </div>
5330: </div>
5331:
5332: <div class="subsection">
1.30 cvs 5333: <h3><a name="sectc4226">Stacking order</a></h3>
1.18 cvs 5334:
1.30 cvs 5335: <p>The <tt>Depth</tt> rule is used to define the stacking order of terminal
5336: boxes when multiple boxes at least partially overlap. This rule defines how
5337: the depth parameter, which is zero or a positive integer, is calculated. The
1.1 cvs 5338: depth parameter has a value for all boxes. For terminal boxes in the
5339: structure and for presentation boxes, the depth value is used during display
5340: and printing: the boxes with the lowest value overlap those with higher
5341: depths. For non-terminal boxes, the depth is not interpreted during display,
1.18 cvs 5342: but it is used to calculate the depth of terminal boxes by inheritance.</p>
1.30 cvs 5343:
5344: <p>Like most other rules, the depth rule is defined in the <a
1.18 cvs 5345: href="#sectc427">default rules</a> of each presentation schema. Thus, there
5346: is always a depth value, even when it is not necessary because there is no
5347: overlapping. To avoid useless operations, a zero value can be given to the
5348: depth parameter, which signifies that overlapping is never a problem.</p>
1.30 cvs 5349:
5350: <p>The depth rule has the same form as the <a href="#sectc4224">visibility
1.18 cvs 5351: rule</a>. It can be defined by inheritance or by a constant numeric value.
5352: When the rule is attached to a numeric attribute, it can take the value of
5353: that attribute.</p>
5354: <pre> 'Depth' ':' NumberInherit</pre>
1.30 cvs 5355:
1.18 cvs 5356: <blockquote class="example">
1.30 cvs 5357: <p><strong>Example:</strong></p>
5358:
5359: <p>For a purely textual document, in which overlapping never poses a
5360: problem, a single default <tt>Depth</tt> rule in the presentation schema is
5361: sufficient:</p>
5362: <pre>DEFAULT
1.1 cvs 5363: Depth : 0;
1.18 cvs 5364: ...</pre>
1.30 cvs 5365:
5366: <p>To make the text of examples appear on a light blue background, a
5367: presentation box is defined:</p>
5368: <pre>BOXES
1.1 cvs 5369: BlueBG :
5370: BEGIN
5371: Content : Graphics 'R';
5372: Background : LightBlue3;
5373: FillPattern: backgroundcolor;
5374: Depth : 2;
5375: ...
1.18 cvs 5376: END;</pre>
1.30 cvs 5377:
5378: <p>and is created by the <tt>Example</tt> element, which has the rules:</p>
5379: <pre>RULES
1.1 cvs 5380: Example :
5381: BEGIN
5382: CreateFirst (BlueBG);
5383: Depth : 1;
5384: ...
1.18 cvs 5385: END;</pre>
1.30 cvs 5386:
5387: <p>In this way, the text of an example (if it inherits its depth from its
5388: ancestor) will be superimposed on a light blue background, and not the
5389: reverse).</p>
1.18 cvs 5390: </blockquote>
5391: </div>
5392:
5393: <div class="subsection">
1.30 cvs 5394: <h3><a name="sectc4227">Line style</a></h3>
1.18 cvs 5395:
1.30 cvs 5396: <p>The <tt>LineStyle</tt> rule determines the style of line which should be
5397: used to draw all the elements contained in the box and the box itself, if it
5398: has a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. The line style can be
1.18 cvs 5399: indicated by a name (<tt>Solid</tt>, <tt>Dashed</tt>, <tt>Dotted</tt>) or it
1.13 cvs 5400: can be inherited. All elements of the graphic base type are affected by this
1.1 cvs 5401: rule, but it can be attached to any box and transmitted by inheritance to the
1.18 cvs 5402: graphic elements. The border of elements having a <a
5403: href="#sectc4230a"><tt>ShowBox</tt> rule</a> is drawn according to the line
5404: style specified by this rule.</p>
1.30 cvs 5405:
5406: <p>Only identical inheritance is allowed: the box takes the same line style as
1.1 cvs 5407: the box from which it inherits. This is indicated by an equals sign after the
1.18 cvs 5408: kinship specification.</p>
5409: <pre> 'LineStyle' ':' LineStyleInherit
1.1 cvs 5410: LineStyleInherit = Kinship '=' /
1.18 cvs 5411: 'Solid' / 'Dashed' / 'Dotted' .</pre>
1.30 cvs 5412:
1.18 cvs 5413: <blockquote class="example">
1.30 cvs 5414: <p><strong>Example:</strong></p>
5415:
5416: <p>To specify that, in Figures, the graphical parts should be drawn in solid
5417: lines, the Figure element is given a rule using the <tt>Solid</tt> name:</p>
5418: <pre>Figure :
1.18 cvs 5419: LineStyle : Solid;</pre>
1.30 cvs 5420:
5421: <p>and the elements composing figures are given an inheritance rule:</p>
5422: <pre> LineStyle : Enclosing =;</pre>
1.18 cvs 5423: </blockquote>
5424: </div>
5425:
5426: <div class="subsection">
1.30 cvs 5427: <h3><a name="sectc4228">Line thickness</a></h3>
1.18 cvs 5428:
1.30 cvs 5429: <p>The <tt>LineWeight</tt> rule determines the thickness of the lines of all
1.1 cvs 5430: graphical elements which appear in the box, no matter what their line style.
5431: Line thickness can be specified by a constant value or by inheritance. A
5432: constant value is a positive number followed by an optional unit specification
1.18 cvs 5433: (which is absent when using relative units). All available <a
5434: href="#sectc4217">distance units</a> can be used. Line thickness is expressed
5435: in the same way as <a href="#sectd42221">line spacing</a>.</p>
5436: <pre> 'LineWeight' ':' DistOrInherit</pre>
1.30 cvs 5437:
5438: <p>All elements of the graphic base type are affected by this rule, but it can
5439: be attached to any box and transmitted by inheritance to the graphic elements.
1.18 cvs 5440: The border of element having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>
5441: is also drawn according to the thickness specified by this rule.</p>
1.30 cvs 5442:
1.18 cvs 5443: <blockquote class="example">
1.30 cvs 5444: <p><strong>Example:</strong></p>
5445:
5446: <p>To specify that, in Figures, the graphical parts should be drawn with
5447: lines 0.3 pt thick, the Figure element is given this rule:</p>
5448: <pre>Figure :
1.18 cvs 5449: LineWeight : 0.3 pt;</pre>
1.30 cvs 5450:
5451: <p>and the elements composing figures are given an inheritance rule:</p>
5452: <pre> LineWeight : Enclosing =;</pre>
1.18 cvs 5453: </blockquote>
5454: </div>
5455:
5456: <div class="subsection">
1.30 cvs 5457: <h3><a name="sectc4229">Fill pattern</a></h3>
1.18 cvs 5458:
1.30 cvs 5459: <p>The <tt>FillPattern</tt> rule determines the pattern used to fill closed
1.1 cvs 5460: graphical elements (circles, rectangles, etc.) which appear in the box. This
1.18 cvs 5461: rule also specifies the pattern used to fill the box associated with elements
5462: having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a><a>. This pattern can
5463: be indicated by a named constant or by inheritance. The named constant
5464: identifies one of the patterns available in Thot. The names of the available
5465: patterns are: nopattern, foregroundcolor, backgroundcolor, gray1, gray2,
5466: gray3, gray4, gray5, gray6, gray7, horiz1, horiz2, horiz3, vert1, vert2,
5467: vert3, left1, left2, left3, right1, right2, right3, square1, square2, square3,
5468: lozenge, brick, tile, sea, basket.</a></p>
1.30 cvs 5469:
5470: <p>Like the other rules peculiar to graphics, <tt>LineStyle</tt> and
1.18 cvs 5471: <tt>LineWeight</tt>, only elements of the graphic base type are affected by
5472: the <tt>FillPattern</tt> rule, but the rule can be attached to any box and
1.1 cvs 5473: transmitted by inheritance to the graphic elements. As with the other rules
1.18 cvs 5474: specific to graphics, only identical inheritance is allowed.</p>
1.30 cvs 5475:
5476: <p>The <tt>FillPattern</tt> rule can also be used to determine whether or not
1.12 cvs 5477: text characters, symbols and pictures should be colored. For these element
5478: types (text, symbols, and pictures), the only valid values are
1.18 cvs 5479: <tt>nopattern</tt>, <tt>foregroundcolor</tt>, and <tt>backgroundcolor</tt>.
5480: When <tt>FillPattern</tt> has the value <tt>backgroundcolor</tt>, text
5481: characters, symbols, and bitmaps are given the color specified by the <a
5482: href="#sectc4230"><tt>Background</tt> rule</a> which applies to these
5483: elements. When <tt>FillPattern</tt> has the value <tt>foregroundcolor</tt>,
5484: these same elements are given the color specified by the <a
5485: href="#sectc4230"><tt>Foreground</tt> rule</a> which applies to these
5486: elements. In all other case, text characters are not colored.</p>
5487: <pre> 'FillPattern' ':' NameInherit</pre>
1.30 cvs 5488:
1.18 cvs 5489: <blockquote class="example">
1.30 cvs 5490: <p><strong>Example:</strong></p>
5491:
5492: <p>To specify that, in Figures, the closed graphical elements should be
5493: filled with a pattern resembling a brick wall, the Figure element is given
5494: this rule:</p>
5495: <pre>Figure :
1.18 cvs 5496: FillPattern : brick;</pre>
1.30 cvs 5497:
5498: <p>and the elements composing figures are given an inheritance rule:</p>
5499: <pre> FillPattern : Enclosing =;</pre>
1.18 cvs 5500: </blockquote>
5501: </div>
5502:
5503: <div class="subsection">
1.30 cvs 5504: <h3><a name="sectc4230">Colors</a></h3>
1.18 cvs 5505:
1.30 cvs 5506: <p>The <tt>Foreground</tt> and <tt>Background</tt> rules determine the
5507: foreground and background colors of the base elements which appear in the box.
5508: They also control the color of boxes associated with elements having a <a
1.18 cvs 5509: href="#sectc4230a"><tt>ShowBox</tt> rule</a>. These colors can be specified
5510: with a named constant or by inheritance. The named constants specify one of
5511: the available colors in Thot. The available color names can be found in the
1.30 cvs 5512: file <tt>thot.color</tt>. In addition to those names, you can use the keyword
5513: <code>Transparent</code>, to not draw anything.</p>
5514:
5515: <p>The color rules affect the same way all base elements and elements having a
5516: <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>, no matter what their type
5517: (text, graphics, pictures, symbols). The color rules can be associated with
5518: any box and can be transmitted by inheritance to the base elements or the
5519: elements having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. Like the
5520: preceding rules, only inheritance of the same value is allowed.</p>
5521: <pre> 'Foreground' ':' Color
5522: 'Background' ':' Color
5523: Color = 'Transparent' / Link '=' / FontColorName .</pre>
5524:
5525: <p><strong>Note:</strong> text colors only appear for text elements whose <a
1.18 cvs 5526: href="#sectc4229">fill pattern</a> does not prevent the use of color.</p>
1.30 cvs 5527:
1.18 cvs 5528: <blockquote class="example">
1.30 cvs 5529: <p><strong>Example:</strong></p>
5530:
5531: <p>To specify that, in Figures, everything must be drawn in blue on a
5532: background of yellow, the Figure element is given these rules:</p>
5533: <pre>Figure :
1.1 cvs 5534: BEGIN
5535: Foreground : Blue;
5536: Background : Yellow;
5537: Fillpattern : backgroundcolor;
1.18 cvs 5538: END;</pre>
1.30 cvs 5539:
5540: <p>and the elements composing figures are given inheritance rules:</p>
5541: <pre> Foreground : Enclosing =;
1.1 cvs 5542: Background : Enclosing =;
1.18 cvs 5543: FillPattern : Enclosing =;</pre>
5544: </blockquote>
5545: </div>
5546:
5547: <div class="subsection">
1.30 cvs 5548: <h3><a name="sectc4230a">Background color and border</a></h3>
1.18 cvs 5549:
1.30 cvs 5550: <p>Boxes associated with structural elements are normally not visible, but it
5551: is possible to draw their border and/or to paint their area when it is needed.
1.18 cvs 5552: This is achieved by associating the <tt>ShowBox</tt> rule with the concerned
1.13 cvs 5553: element. This rule has no parameter and no value. It is simply written
1.18 cvs 5554: <tt>Showbox;</tt>. It is not inherited nor transmitted to any other element.
5555: It applies only to the element with which it is associated.</p>
5556: <pre> 'ShowBox'</pre>
1.30 cvs 5557:
5558: <p>When an element has a <tt>ShowBox</tt> rule, the border is drawn only if
5559: the <tt>LineWeight</tt> rule that applies to that element has a non-zero value
1.18 cvs 5560: (this value can be inherited). The color, style and thickness of the border
5561: are defined by the <tt>Foreground</tt>, <tt>LineStyle</tt>, and
5562: <tt>LineWeight</tt> rules that apply to the element.</p>
1.30 cvs 5563:
5564: <p>When an element has a <tt>ShowBox</tt> rule, the background of this element
5565: is paint only if the value of the <tt>FillPattern</tt> rule that applies to
5566: that element is not <tt>nopattern</tt>. The pattern and color(s) of the
5567: background are defined by the <tt>FillPattern</tt>, <tt>Background</tt>, and
1.18 cvs 5568: <tt>Foreground</tt> rules that apply to the element.</p>
5569: </div>
5570:
5571: <div class="subsection">
1.30 cvs 5572: <h3><a name="sectc4230b">Background pictures</a></h3>
1.18 cvs 5573:
1.30 cvs 5574: <p>The <tt>BackgroundPicture</tt> rule allows to display a picture as the
1.13 cvs 5575: background of an element. It has a single parameter, the file name of the
1.18 cvs 5576: picture. This is a string delimited by single quotes. If the first character
5577: in this string is '/', it is considered as an absolute path, otherwise the
5578: file is searched for along the schema directory path. This file may contain a
5579: picture in any format accepted by Thot (xbm, xpm, gif, jpeg, png, etc.)</p>
1.30 cvs 5580:
5581: <p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
1.13 cvs 5582: the element with which they are associated. They are not inherited nor
1.18 cvs 5583: transmitted to children elements.</p>
1.30 cvs 5584:
5585: <p>The background picture has not always the same size as the element's box.
1.13 cvs 5586: There are diffrent ways to fill the element box with the picture. This is
1.18 cvs 5587: specified by the <tt>PictureMode</tt> rule, which should be associated to the
5588: same element. This rule may take one of the following values:</p>
5589: <dl>
1.30 cvs 5590: <dt><tt>NormalSize</tt></dt>
5591: <dd>The picture is centered in the box, and clipped if it is too
5592: large.</dd>
5593: <dt><tt>Scale</tt></dt>
5594: <dd>The picture is zoomed to fit the box size.</dd>
5595: <dt><tt>RepeatX</tt></dt>
5596: <dd>The picture is repeated horizontally to fit the box width.</dd>
5597: <dt><tt>RepeatY</tt></dt>
5598: <dd>The picture is repeated vertically to fit the box height.</dd>
5599: <dt><tt>RepeatXY</tt></dt>
5600: <dd>The picture is repeated both horizontally and vertically to fill the
5601: box.</dd>
1.18 cvs 5602: </dl>
1.30 cvs 5603:
5604: <p>If an element has a <tt>BackgroundPicture</tt> rule and no
1.18 cvs 5605: <tt>PictureMode</tt> rule, the <tt>NormalSize</tt> value is assumed.</p>
5606: <pre> 'BackgroundPicture' ':' FileName /
1.13 cvs 5607: 'PictureMode' ':' PictMode .
5608:
5609: FileName = STRING .
1.18 cvs 5610: PictMode = 'NormalSize' / 'Scale' / 'RepeatXY' / 'RepeatX' / 'RepeatY' .</pre>
1.30 cvs 5611:
5612: <p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
1.13 cvs 5613: the element with which they are associated. They are not inherited nor
1.18 cvs 5614: transmitted to children elements.</p>
5615: </div>
1.13 cvs 5616:
1.18 cvs 5617: <div class="subsection">
1.30 cvs 5618: <h3><a name="sectc4231">Presentation box content</a></h3>
1.1 cvs 5619:
1.30 cvs 5620: <p>The <tt>Content</tt> rule applies to presentation boxes. It indicates the
1.1 cvs 5621: content given to a box. This content is either a variable's value or a
1.18 cvs 5622: constant value. In the special case of <a href="#sectc4233">header or footer
5623: boxes</a>, the content can also be a structured element type.</p>
1.30 cvs 5624:
5625: <p>If the content is a constant, it can be specified, as in a variable
1.18 cvs 5626: declaration, either by the name of a constant declared in the <tt>CONST</tt>
1.1 cvs 5627: section or by direct specification of the type and value of the box's
1.18 cvs 5628: content.</p>
1.30 cvs 5629:
5630: <p>Similarly, if it is a variable, the name of a variable declared in
1.18 cvs 5631: <tt>VAR</tt> section can be given or the variable may be defined within
5632: parentheses. The content inside the parentheses has the same syntax as a <a
5633: href="#sectc426">variable declaration</a>.</p>
1.30 cvs 5634:
5635: <p>When the content is a structured element type, the name of the element type
5636: is given after the colon. In this case, the box's content is all elements of
1.1 cvs 5637: the named type which are designated by references which are part of the page
1.18 cvs 5638: on which the header or footer with this <tt>Content</tt> rule appears. Only
5639: associated elements can appear in a <tt>Content</tt> rule and the structure
1.1 cvs 5640: must provide references to these elements. Moreover, the box whose content
5641: they are must be a header or footer box generated by a page box of the primary
1.18 cvs 5642: view.</p>
5643: <pre> 'Content' ':' VarConst
1.1 cvs 5644: VarConst = ConstID / ConstType ConstValue /
5645: VarID / '(' FunctionSeq ')' /
1.18 cvs 5646: ElemID .</pre>
1.30 cvs 5647:
5648: <p>A presentation box can have only one <tt>Content</tt> rule, which means
5649: that the content of a presentation box cannot vary from view to view. However,
5650: such an effect can be achieved by creating several presentation boxes, each
5651: with different content and visible in different views.</p>
5652:
5653: <p>The <tt>Content</tt> rule also applies to elements defined as references in
1.1 cvs 5654: the structure schema. In this case, the content defined by the rule must be
5655: a constant. It is this content which appears on the screen or paper to
5656: represent references of the type to which the rule applies. A reference can
1.18 cvs 5657: have a <tt>Content</tt> rule or a <a href="#sectc4234"><tt>Copy</tt> rule</a>
1.1 cvs 5658: for each view. If neither of these rules appears, the reference is displayed
1.18 cvs 5659: as <tt>[*]</tt>, which is equivalent to the rule:</p>
5660: <pre> Content: Text '[*]';</pre>
1.30 cvs 5661:
1.18 cvs 5662: <blockquote class="example">
1.30 cvs 5663: <p><strong>Example:</strong></p>
5664:
5665: <p>The content of the presentation box created to make the chapter number
5666: and section number appear before each section title can be defined by:</p>
5667: <pre>BOXES
1.1 cvs 5668: SectionNumBox :
5669: BEGIN
5670: Content : NumSection;
5671: ...
1.18 cvs 5672: END;</pre>
1.30 cvs 5673:
5674: <p>if the <tt>NumSection</tt> variable has been defined in the variable
5675: definition section of the presentation schema. Otherwise the
5676: <tt>Content</tt> would be written:</p>
5677: <pre>BOXES
1.1 cvs 5678: SectionNumBox :
5679: BEGIN
5680: Content : (VALUE (ChapterCtr, Roman) TEXT '.'
5681: VALUE (SectionCtr, Arabic));
5682: ...
1.18 cvs 5683: END;</pre>
1.30 cvs 5684:
5685: <p>To specify that a page footer should contain all elements of the
5686: <tt>Note</tt> type are referred to in the page, the following rule is
5687: written:</p>
5688: <pre>BOXES
1.1 cvs 5689: NotesFooterBox :
5690: BEGIN
5691: Content : Note;
5692: ...
1.18 cvs 5693: END;</pre>
1.30 cvs 5694:
5695: <p><tt>Note</tt> is defined as an associated element in the structure schema
5696: and NotesFooterBox is created by a page box of the primary view.</p>
1.18 cvs 5697: </blockquote>
5698: </div>
1.1 cvs 5699:
1.18 cvs 5700: <div class="subsection">
1.30 cvs 5701: <h3><a name="sectc4232">Presentation box creation</a></h3>
1.1 cvs 5702:
1.30 cvs 5703: <p>A creation rule specifies that a presentation box should be created when an
1.18 cvs 5704: element of the type to which the rule is attached appears in the document.</p>
1.30 cvs 5705:
5706: <p>A keyword specifies the position, relative to the creating box, at which
5707: the created box will be placed in the structure:</p>
1.18 cvs 5708: <dl>
1.30 cvs 5709: <dt><tt>CreateFirst</tt></dt>
5710: <dd>specifies that the box should be created as the first box of the next
5711: lower level, before any already existing boxes, and only if the
5712: beginning of the creating element is visible;</dd>
5713: <dt><tt>CreateLast</tt></dt>
5714: <dd>specifies that the box should be created as the last box of the next
5715: lower level, after any existing boxes, and only if the end of the
5716: creating element is visible;</dd>
5717: <dt><tt>CreateBefore</tt></dt>
5718: <dd>specifies that the box should be created before the creating box, on
5719: the same level as the creating box, and only if the beginning of the
5720: creating element is visible;</dd>
5721: <dt><tt>CreateAfter</tt></dt>
5722: <dd>specifies that the box should be created after the creating box, on
5723: the same level as the creating box, and only if the beginning of the
5724: creating element is visible;</dd>
5725: <dt><tt>CreateEnclosing</tt></dt>
5726: <dd>specifies that the box should be created at the upper level relatively
5727: to the creating box, and that it must contain that creating box and all
5728: presentation boxes created by the same creating box.</dd>
1.18 cvs 5729: </dl>
1.30 cvs 5730:
5731: <p>This keyword can be followed by the <tt>Repeated</tt> keyword to indicate
5732: that the box must be created for each part of the creating element. These
5733: parts result from the division of the element by page breaks or column
5734: changes. If the <tt>Repeated</tt> keyword is missing, the box is only created
5735: for the first part of the creating element (<tt>CreateFirst</tt> and
1.18 cvs 5736: <tt>CreateBefore</tt> rules) or for the last part (<tt>CreateLast</tt> and
5737: <tt>CreateAfter</tt> rules).</p>
1.30 cvs 5738:
5739: <p>The type of presentation to be created is specified at the end of the rule
1.18 cvs 5740: between parentheses.</p>
1.30 cvs 5741:
5742: <p>Creation rules cannot appear in the <a href="#sectc427">default
5743: presentation rules</a>. The boxes being created should have a
5744: <tt>Content</tt> rule which indicates their <a
5745: href="#sectc4231">content</a>.</p>
5746:
5747: <p>Creation rules can only appear in the block of rules for the primary view;
1.1 cvs 5748: creation is provoked by a document element for all views. However, for each
5749: view, the presentation box is only created if the creating element is itself a
5750: box in the view. Moreover, the visibility parameter of the presentation box
5751: can be adjusted to control the creation of the box on a view-by-view
1.18 cvs 5752: basis.</p>
5753: <pre> Creation '(' BoxID ')'
1.1 cvs 5754: Creation = Create [ 'Repeated' ] .
5755: Create ='CreateFirst' / 'CreateLast' /
5756: 'CreateBefore' / 'CreateAfter' /
1.18 cvs 5757: 'CreateEnclosing' .</pre>
1.30 cvs 5758:
1.18 cvs 5759: <blockquote class="example">
1.30 cvs 5760: <p><strong>Example:</strong></p>
5761:
5762: <p>Let us define an object type, called Table, which is composed of a
5763: sequence of columns, all having the same fixed width, where the columns are
5764: separated by vertical lines. There is a line to the left of the first
5765: column and one to the right of the last. Each column has a variable number
1.31 cvs 5766: of cells, placed one on top of the other and separated by horizontal lines.
5767: There are no horizontal lines above the first cell or below the last cell.
1.30 cvs 5768: The text contained in each cell is broken into lines and these lines are
5769: centered horizontally in the cell. The logical structure of this object is
5770: defined by:</p>
5771: <pre>Table = LIST OF (Column);
1.18 cvs 5772: Column = LIST OF (Cell = Text);</pre>
5773:
1.30 cvs 5774: <div class="figure">
5775: <hr>
5776: <pre>| | | |
1.1 cvs 5777: | xx xxxx xxxx |x xxxx xxx xxxxx| x xxx x xxx |
5778: | xxx xxx xxxx x | x xx x xxx | xxxxx xxxx xx |
5779: | xxxxx xxxx |----------------| xxx xxxxx x |
5780: | xxxxx xxx xxxx | xxxx xx xx xxx | xx xx |
5781: | xxx xxxx x xxx | xxxx x xxx x |---------------|
5782: |----------------| xxx xxxx xxxxx | xxxxx xxxxx |
5783: | xxx xxx xxxxxx |----------------| xxx xxxx xxxx |
5784: | xxxx xxxx xx | xxxx xx x xx | xxx xx x xx |
5785: |----------------| xxx xxxxx xxxx | xxxx xxxx xxx |
5786: | xxxxx xxx xxxx | xxxx xx x xx | xxxxx xxx |
1.18 cvs 5787: |xxxx xx x xxxxxx| xxxx xx xxxxxx | xxxxx xxxxx |</pre>
1.19 cvs 5788:
1.30 cvs 5789: <p align="center"><em><a name="table">The design of a table</a></em></p>
5790: <hr>
5791: </div>
5792:
5793: <p>The presentation of the table should resemble the design of the above <a
5794: href="#table">figure</a>. It is defined by the following presentation
5795: schema fragment:</p>
5796: <pre>BOXES
1.1 cvs 5797: VertLine : BEGIN
5798: Width : 0.3 cm;
5799: Height : Enclosing . Height;
5800: VertPos : Top = Enclosing . Top;
5801: HorizPos : Left = Previous . Right;
5802: Content : Graphics 'v';
5803: END;
5804:
5805: HorizLine: BEGIN
5806: Width : Enclosing . Width;
5807: Height : 0.3 cm;
5808: VertPos : Top = Previous . Bottom;
5809: HorizPos : Left = Enclosing . Left;
5810: Content : Graphics 'h';
5811: END;
5812:
5813: RULES
1.6 cvs 5814: Column : BEGIN
5815: CreateBefore (VertLine);
5816: IF LAST CreateAfter (VertLine);
5817: Width : 2.8 cm;
5818: Height : Enclosed . Height;
5819: VertPos : Top = Enclosing . Top;
5820: HorizPos : Left = Previous . Right;
5821: END;
5822:
5823: Cell : BEGIN
5824: IF NOT FIRST CreateBefore (HorizLine);
5825: Width : Enclosing . Width;
5826: Height : Enclosed . Height;
5827: VertPos : Top = Previous . Bottom;
5828: HorizPos : Left = Enclosing . Left;
5829: Line;
5830: Adjust : VMiddle;
1.18 cvs 5831: END;</pre>
1.30 cvs 5832:
5833: <p>It is useful to note that the horizontal position rule of the first
5834: vertical line will not be applied, since there is no preceding box. In this
5835: case, the box is simply placed on the left side of the enclosing box.</p>
1.18 cvs 5836: </blockquote>
5837: </div>
5838:
5839: <div class="subsection">
1.30 cvs 5840: <h3><a name="sectc4233">Page layout</a></h3>
1.18 cvs 5841:
1.30 cvs 5842: <p>The page models specified in the <tt>Page</tt> rule are defined by boxes
1.18 cvs 5843: declared in the <tt>BOXES</tt> section of the presentation schema. Pages are
1.1 cvs 5844: not described as frames which will be filled by the document's text, but as
5845: element are inserted in the flow of the document and which mark the page
5846: breaks. Each of these page break elements contains presentation boxes which
5847: represent the footer boxes of a page followed by header boxes of the next
5848: page. The page box itself is the simple line which separates two pages on the
5849: screen. Both the footer and header boxes placed themselves with respect to
5850: this page box, with the footer being placed above it and the header boxes
1.18 cvs 5851: being placed above it.</p>
1.30 cvs 5852:
5853: <p>The boxes created by a page box are headers and footers and can only place
1.1 cvs 5854: themselves vertically with respect to the page box itself (which is in fact
5855: the separation between two pages). Besides, it is their vertical position
5856: rule which determines whether they are header or footer boxes. Header and
5857: footer boxes must have an explicit vertical position rule (they must not use
1.18 cvs 5858: the default rule).</p>
1.30 cvs 5859:
5860: <p>Footer boxes must have an absolute height or inherit the height of their
1.18 cvs 5861: contents:</p>
5862: <pre>Height : Enclosed . Height;</pre>
1.30 cvs 5863:
5864: <p>A page box must have height and width rules and these two rules must be
1.1 cvs 5865: specified with constant values, expressed in centimeters, inches, or
5866: typographer's points. These two rules are interpreted in a special way for
5867: page boxes: they determine the width of the page and the vertical distance
5868: between two page separators, which is the height of the page and its header
1.18 cvs 5869: and footer together.</p>
1.30 cvs 5870:
5871: <p>A page box should also have vertical and horizontal position rules and
5872: these two rules should specify the position on the sheet of paper of the
5873: rectangle enclosing the page's contents. These two rules must position the
5874: upper left corner of the enclosing rectangle in relation to the upper left
5875: corner of the sheet of paper, considered to be the enclosing element. In both
5876: rules, distances must be expressed in fixed units: centimeters (<tt>cm</tt>),
5877: inches (<tt>in</tt>), or typographer's points (<tt>pt</tt>). Thus, rules
5878: similar to the following should be found in the rules for a page box:</p>
1.18 cvs 5879: <pre>BOXES
1.1 cvs 5880: ThePage :
5881: BEGIN
5882: VertPos : Top = Enclosing . Top + 3 cm;
5883: HorizPos : Left = Enclosing . Left + 2.5 cm;
5884: Width : 16 cm;
5885: Height : 22.5 cm;
1.18 cvs 5886: END;</pre>
1.30 cvs 5887:
5888: <p>When a document must be page broken, the page models to be constructed are
1.18 cvs 5889: defined in the <tt>BOXES</tt> section of the presentation schema by declaring
5890: page boxes and header and footer boxes. Also, the <tt>Page</tt> rule is used
1.1 cvs 5891: to specify to which parts of the document and to which views each model should
1.18 cvs 5892: be applied.</p>
1.30 cvs 5893:
5894: <p>The <tt>Page</tt> rule has only one parameter, given between parentheses
5895: after the <tt>Page</tt> keyword. This parameter is the name of the box which
5896: must serve as the model for page construction. When a <tt>Page</tt> rule is
1.1 cvs 5897: attached to an element type, each time such an element appears in a document,
5898: a page break takes place and the page model indicated in the rule is applied
5899: to all following pages, until reaching the next element which has a
1.18 cvs 5900: <tt>Page</tt> rule.</p>
1.30 cvs 5901:
5902: <p>The <tt>Page</tt> rule applies to only one view; if it appears in the
5903: primary view's block of rules, a <tt>Page</tt> rule applies only to that view.
5904: Thus, different page models can be defined for the full document and for its
5905: table of contents, which is another view of the same document. Some views can
5906: be specified with pages, and other views of the same document can be specified
1.18 cvs 5907: without pages.</p>
5908: <pre> 'Page' '(' BoxID ')'</pre>
5909: </div>
5910:
5911: <div class="subsection">
1.30 cvs 5912: <h3><a name="sectc4234">Box copies</a></h3>
1.18 cvs 5913:
1.30 cvs 5914: <p>The <tt>Copy</tt> rule can be used for an element which is defined as a
1.7 cvs 5915: reference in the structure schema. In this case, the rule specifies, between
1.18 cvs 5916: parenthesis, the name of the box (declared in the <tt>BOXES</tt> section)
1.1 cvs 5917: which must be produced when this reference appears in the structure of a
5918: document. The box produced is a copy (same contents, but possible different
5919: presentation) of the box type indicated by the parameter between parentheses,
5920: and which is in the element designated by the reference. The name of a box
5921: can be replaced by type name. Then what is copied is the contents of the
1.18 cvs 5922: element of this type which is inside the referenced element.</p>
1.30 cvs 5923:
5924: <p>Whether a box name or type name is given, it may be followed by the name of
5925: a structure schema between parentheses. This signifies that the box or type
5926: is defined in the indicated structure schema and not in the structure schema
5927: with which the rule's presentation schema is associated.</p>
5928:
5929: <p>The <tt>Copy</tt> rule can also be applied to a presentation box. If the
1.1 cvs 5930: presentation box was created by a reference attribute, the rule is applied as
5931: in the case of a reference element: the contents of the box having the
1.18 cvs 5932: <tt>Copy</tt> rule are based on the element designated by the reference
5933: attribute. For other presentation boxes, the <tt>Copy</tt> rule takes a type
1.1 cvs 5934: name parameter which can be followed, between parentheses, by the name of the
5935: structure schema in which the type is defined, if it is not defined in the
5936: same schema. The contents of the box which has this rule are a copy of the
5937: element of this type which is in the element creating the presentation box, or
5938: by default, the box of this type which precedes the presentation box. This
5939: last facility is used, for example, to define the running titles in headers or
1.18 cvs 5940: footers.</p>
5941: <pre> 'Copy' '(' BoxTypeToCopy ')' .
1.1 cvs 5942: BoxTypeToCopy = BoxID [ ExtStruct ] /
1.6 cvs 5943: ElemID [ ExtStruct ] .
1.18 cvs 5944: ExtStruct = '(' ElemID ')' .</pre>
1.30 cvs 5945:
5946: <p>Like the creation rules, the <tt>Copy</tt> rule cannot appear in the <a
1.18 cvs 5947: href="#sectc427">default presentation rules</a>. Moreover, this rule can only
5948: appear in the primary view's block of rules; the copy rule is applied to all
5949: views.</p>
1.30 cvs 5950:
1.18 cvs 5951: <blockquote class="example">
1.30 cvs 5952: <p><strong>Example:</strong></p>
5953:
5954: <p>If the following definitions are in the structure schema:</p>
5955: <pre>Body = LIST OF (Chapter =
1.1 cvs 5956: BEGIN
5957: ChapterTitle = Text;
5958: ChapterBody = SectionSeq;
5959: END);
1.18 cvs 5960: RefChapter = REFERENCE (Chapter);</pre>
1.30 cvs 5961:
5962: <p>then the following presentation rules (among many other rules in the
5963: presentation schema) can be specified:</p>
5964: <pre>COUNTERS
1.1 cvs 5965: ChapterCtr : RANK OF Chapter;
5966: BOXES
5967: ChapterNumber :
5968: BEGIN
5969: Content : (VALUE (ChapterCtr, URoman));
5970: ...
5971: END;
5972: RULES
5973: Chapter :
5974: BEGIN
5975: CreateFirst (ChapterNumber);
5976: ...
5977: END;
5978: RefChapter :
5979: BEGIN
5980: Copy (ChapterNumber);
5981: ...
1.18 cvs 5982: END;</pre>
1.30 cvs 5983:
5984: <p>which makes the number of the chapter designated by the reference appear
5985: in uppercase roman numerals, in place of the reference to a chapter itself.
5986: Alternatively, the chapter title can be made to appear in place of the
5987: reference by writing this <tt>Copy</tt>rule:</p>
5988: <pre> Copy (ChapterTitle);</pre>
5989:
5990: <p>To define a header box, named <tt>RunningTitle</tt>, which contains the
5991: title of the current chapter, the box's contents are defined in this
5992: way:</p>
5993: <pre>BOXES
1.1 cvs 5994: RunningTitle :
1.18 cvs 5995: Copy (ChapterTitle);</pre>
5996: </blockquote>
5997: </div>
5998: </div>
5999: <hr>
6000: </div>
1.1 cvs 6001:
1.18 cvs 6002: <div class="chapter">
6003: <h1><a name="sect5">The T language</a></h1>
1.1 cvs 6004:
1.18 cvs 6005: <div class="section">
1.30 cvs 6006: <h2><a name="sectb51">Document translation</a></h2>
1.1 cvs 6007:
1.30 cvs 6008: <p>Because of its document model, Thot can produce documents in a high-level
1.18 cvs 6009: abstract form. This form, called the <em>canonical form</em> is specific to
1.1 cvs 6010: Thot; it is well suited to the editor's manipulations, but it does not
6011: necessarily suit other operations which might be applied to documents. Because
6012: of this, the Thot editor offers the choice of saving documents in its own form
6013: (the canonical form) or a format defined by the user. In the latter case, the
6014: Thot document is transformed by the translation program. This facility can
6015: also be used to export documents from Thot to systems using other
1.18 cvs 6016: formalisms.</p>
1.1 cvs 6017:
1.18 cvs 6018: <div class="subsection">
1.30 cvs 6019: <h3><a name="sectc511">Translation principles</a></h3>
1.1 cvs 6020:
1.30 cvs 6021: <p>Document translation allows the export of documents to other systems which
6022: do not accept Thot's canonical form. Translation can be used to export
6023: document to source-based formatters like T<sub><big>E</big></sub>X,
1.18 cvs 6024: L<sup>A</sup>T<sub><big>E</big></sub>X, and <tt>troff</tt>. It can also be
1.1 cvs 6025: used to translate documents into interchange formats like SGML or HTML. To
6026: allow the widest range of possible exports, Thot does not limit the choice of
6027: translations, but rather allows the user to define the formalisms into which
1.18 cvs 6028: documents can be translated.</p>
1.30 cvs 6029:
6030: <p>For each document or object class, a set of translation rules can be
6031: defined, specifying how the canonical form should be transformed into a given
1.18 cvs 6032: formalism. These translation rules are grouped into <em>translation
6033: schemas</em>, each schema containing the rules necessary to translate a
1.1 cvs 6034: generic logical structure (document or object structure) into a particular
6035: formalism. The same generic logical structure can have several different
6036: translation schemas, each defining translation rules for a different
1.18 cvs 6037: formalism.</p>
1.30 cvs 6038:
6039: <p>Like presentation schemas, translation schemas are generic. Thus, they
6040: apply to an entire object or document class and permit translation of all
6041: documents or objects of that class.</p>
1.18 cvs 6042: </div>
1.1 cvs 6043:
1.18 cvs 6044: <div class="subsection">
1.30 cvs 6045: <h3><a name="sectc512">Translation procedure</a></h3>
1.1 cvs 6046:
1.30 cvs 6047: <p>The translator works on the specific logical structure of the document
6048: being translated. It traverses the primary tree of this logical structure in
1.1 cvs 6049: pre-order and, at each node encountered, it applies the corresponding
6050: translation rules defined in the translation schema. Translation can be
1.18 cvs 6051: associated:</p>
6052: <ul>
1.30 cvs 6053: <li>with element types defined in the structure schema,</li>
6054: <li>with global or local attributes defined in the structure schema,</li>
6055: <li>with specific presentation rules,</li>
6056: <li>with the content of the leaves of the structure (characters, symbols
6057: and graphical elements)</li>
1.18 cvs 6058: </ul>
1.30 cvs 6059:
6060: <p>Thus, for each node, the translator applies all rules associated with the
1.1 cvs 6061: element type, all rules associated with each attribute (local or global)
6062: carried by the element, and if the element is a leaf of the tree, it also
1.10 cvs 6063: applies translation rules for characters, symbols, or graphical elements,
1.18 cvs 6064: depending on the type of the leaf.</p>
1.30 cvs 6065:
6066: <p>Rules associated with the content of leaves are different from all other
1.1 cvs 6067: rules: they specify only how to translate character strings, symbols, and
6068: graphical elements. All other rules, whether associated with element types,
6069: with specific presentation rules or with attributes, are treated similarly.
1.18 cvs 6070: These rules primarily allow:</p>
6071: <ul>
1.30 cvs 6072: <li>generation of a text constant or variable before or after the contents
6073: of an element,</li>
6074: <li>modification of the order in which elements appear after
6075: translation,</li>
6076: <li>removal of an element in the translated document,</li>
6077: <li>and writing messages on the user's terminal during translation.</li>
1.18 cvs 6078: </ul>
6079: </div>
6080: </div>
1.1 cvs 6081:
1.18 cvs 6082: <div class="section">
1.30 cvs 6083: <h2><a name="sectb52">Translation definition language</a></h2>
1.1 cvs 6084:
1.30 cvs 6085: <p>Translation schemas are written in a custom language, called T, which is
1.1 cvs 6086: described in the rest of this chapter. The grammar of T is specified using
1.18 cvs 6087: the same <a href="#sectc321">meta-language</a> as was used for the S and P
1.1 cvs 6088: languages and the translation schemas are written using the same conventions
6089: as the structure and presentation schemas. In particular, the keywords of the
6090: T language (the stings between apostrophes in the following syntax rules) can
6091: be written in any combination of upper-case and lower-case letters, but
6092: identifiers created by the programmer must always be written in the same
1.18 cvs 6093: way.</p>
1.1 cvs 6094:
1.18 cvs 6095: <div class="subsection">
1.30 cvs 6096: <h3><a name="sectc521">Organization of a translation schema</a></h3>
1.1 cvs 6097:
1.30 cvs 6098: <p>A translation schema is begun by the <tt>TRANSLATION</tt> keyword and is
1.18 cvs 6099: terminated by the <tt>END</tt> keyword. The <tt>TRANSLATION</tt> keyword is
1.1 cvs 6100: followed by the name of the generic structure for which a translation is being
6101: defined and a semicolon. This name must be identical to the name which
1.18 cvs 6102: appears after the <tt>STRUCTURE</tt> keyword in the corresponding structure
6103: schema.</p>
1.30 cvs 6104:
6105: <p>After this declaration of the structure, the following material appears in
1.18 cvs 6106: order:</p>
6107: <ul>
1.30 cvs 6108: <li>the length of lines produced by the translation,</li>
6109: <li>the character delimiting the end of the line,</li>
6110: <li>the character string which the translator will insert if it must
6111: line-break the translated text,</li>
6112: <li>declarations of
6113: <ul>
6114: <li>buffers,</li>
6115: <li>counters,</li>
6116: <li>constants,</li>
6117: <li>variables,</li>
6118: </ul>
6119: </li>
6120: <li>translation rules associated with element types,</li>
6121: <li>translation rules associated with attributes,</li>
6122: <li>translation rules associated with specific presentation rules,</li>
6123: <li>translation rules associated with characters strings, symbols and
6124: graphical elements.</li>
1.18 cvs 6125: </ul>
1.30 cvs 6126:
6127: <p>Each of these sections is introduced by a keyword followed by a sequence of
1.1 cvs 6128: declarations. All of these sections are optional, expect for the translation
1.18 cvs 6129: rules associated with element types. Many <tt>TEXTTRANSLATE</tt> sections can
1.1 cvs 6130: appear, each defining the rules for translating character strings of a
1.18 cvs 6131: particular alphabet.</p>
6132: <pre> TransSchema ='TRANSLATION' ElemID ';'
1.1 cvs 6133: [ 'LINELENGTH' LineLength ';' ]
6134: [ 'LINEEND' CHARACTER ';' ]
6135: [ 'LINEENDINSERT' STRING ';' ]
6136: [ 'BUFFERS' BufferSeq ]
6137: [ 'COUNTERS' CounterSeq ]
6138: [ 'CONST' ConstSeq ]
6139: [ 'VAR' VariableSeq ]
6140: 'RULES' ElemSeq
6141: [ 'ATTRIBUTES' AttrSeq ]
6142: [ 'PRESENTATION' PresSeq ]
1.30 cvs 6143: < 'TEXTTRANSLATE' TextTransSeq >
1.1 cvs 6144: [ 'SYMBTRANSLATE' TransSeq ]
6145: [ 'GRAPHTRANSLATE' TransSeq ]
1.18 cvs 6146: 'END' .</pre>
6147: </div>
1.1 cvs 6148:
1.18 cvs 6149: <div class="subsection">
1.30 cvs 6150: <h3><a name="sectc522">Line length</a></h3>
1.1 cvs 6151:
1.30 cvs 6152: <p>If a <tt>LINELENGTH</tt> instruction is present after the structure
1.1 cvs 6153: declaration, the translator divides the text it produces into lines, each line
6154: having a length less than or equal to the integer which follows the
1.18 cvs 6155: <tt>LINELENGTH</tt> keyword. This maximum line length is expressed as a
1.1 cvs 6156: number of characters. The end of the line is marked by the character defined
1.18 cvs 6157: by the <tt>LINEEND</tt> instruction. When the translator breaks the lines on
1.1 cvs 6158: a space character in generated text, this space will be replaced by the
1.18 cvs 6159: character string defined by the <tt>LINEENDINSERT</tt> instruction.</p>
1.30 cvs 6160:
6161: <p>If the <tt>LINEEND</tt> instruction is not defined then the linefeed
6162: character (octal code 12) is used as the default line end character. If the
1.18 cvs 6163: <tt>LINEENDINSERT</tt> instruction is not defined, the linefeed character is
6164: inserted at the end of the produced lines. If there is no <tt>LINELENGTH</tt>
1.1 cvs 6165: instruction, the translated text is not divided into lines. Otherwise, if the
6166: translation rules generate line end marks, these marks remain in the
6167: translated text, but the length of the lines is not controlled by the
1.18 cvs 6168: translator.</p>
6169: <pre> LineLength = NUMBER .</pre>
1.30 cvs 6170:
1.18 cvs 6171: <blockquote class="example">
1.30 cvs 6172: <p><strong>Example:</strong></p>
6173:
6174: <p>To limit the lines produced by the translator to a length of 80
6175: characters, the following rule is written at the beginning of the
6176: translation schema.</p>
6177: <pre>LineLength 80;</pre>
1.18 cvs 6178: </blockquote>
6179: </div>
1.1 cvs 6180:
1.18 cvs 6181: <div class="subsection">
1.30 cvs 6182: <h3><a name="sectc523">Buffers</a></h3>
1.1 cvs 6183:
1.30 cvs 6184: <p>A buffer is a unit of memory managed by the translator, which can either
1.18 cvs 6185: contain text read from the terminal during the translation (see the <a
6186: href="#sectc5212"><tt>Read</tt> rule</a>), or the name of the last picture
1.1 cvs 6187: (bit-map) encountered by the translator in its traversal of the document.
1.2 cvs 6188: Remember the pictures are stored in files that are separate for the document
1.1 cvs 6189: files and that the canonical form contains only the names of the files in
1.18 cvs 6190: which the pictures are found.</p>
1.30 cvs 6191:
6192: <p>Thus, there are two types of buffers: buffers for reading from the
6193: terminal (filled by the <tt>Read</tt> rule) and the buffer of picture names
6194: (containing the name of the last picture encountered). A translation schema
6195: can use either type, one or several read buffers and one (and only one)
6196: picture name buffer.</p>
6197:
6198: <p>If any buffers are used, the <tt>BUFFERS</tt> keyword must be present,
1.1 cvs 6199: followed by declarations of every buffer used in the translation schema. Each
6200: buffer declaration is composed only of the name of the buffer, chosen freely
1.2 cvs 6201: by the programmer. The picture name buffer is identified by the
1.18 cvs 6202: <tt>Picture</tt> keyword, between parentheses, following the buffer name. The
6203: <tt>Picture</tt> keyword may only appear once. Each buffer declaration is
6204: terminated by a semicolon.</p>
1.30 cvs 6205: <pre> BufferSeq = Buffer < Buffer > .
1.1 cvs 6206: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
1.18 cvs 6207: BufferID = NAME .</pre>
1.30 cvs 6208:
1.18 cvs 6209: <blockquote class="example">
1.30 cvs 6210: <p><strong>Example:</strong></p>
6211:
6212: <p>The following buffer declarations create a picture name buffer named
6213: <tt>pictureName</tt> and a read buffer named <a
6214: name="destname"><tt>DestName</tt></a>:</p>
6215: <pre>BUFFERS
1.18 cvs 6216: pictureName (Picture); DestName;</pre>
6217: </blockquote>
6218: </div>
1.1 cvs 6219:
1.18 cvs 6220: <div class="subsection">
1.30 cvs 6221: <h3><a name="sectc524">Counters</a></h3>
6222:
6223: <p>Certain translation rules generate text that varies according to the
6224: context of the element to which the rules apply. Variable text is defined
6225: either in the <a href="#sectc526"><tt>VAR</tt> section</a> of the translation
6226: schema or in the rule itself (see the <tt>Create</tt> and <tt>Write</tt>
6227: rules). Both types of definition rely on counters for the calculation of
6228: variable material.</p>
6229:
6230: <p>There are two types of counter: counters whose value is explicitely
6231: computed by applying <a href="#sectc5221"><tt>Set</tt> and <tt>Add</tt>
6232: rules</a>, and counters whose value is computed by a function associated with
6233: the counter. Those functions allow the same calculations as can be used in
6234: presentation schemas. As in a presentation schema, counters must be defined in
6235: the <tt>COUNTERS</tt> section of the translation schema before they are
6236: used.</p>
6237:
6238: <p>When counters are used in a translation schema, the <tt>COUNTERS</tt>
6239: keyword is followed by the declarations of every counter used. Each
6240: declaration is composed of the counter's name possibly followed by a colon and
6241: the counting function to be used for the counter. The declaration is
6242: terminated by a semi-colon. If the counter is explicitely computed by
6243: <tt>Set</tt> and <tt>Add</tt> rules, no counting function is indicated. If a
6244: counting function is indicated, <tt>Set</tt> and <tt>Add</tt> rules cannot be
6245: applied to that counter.</p>
1.1 cvs 6246:
1.30 cvs 6247: <p>The counting function indicates how the counter's value will be computed.
1.18 cvs 6248: Three functions are available: <tt>Rank</tt>, <tt>Rlevel</tt>, and
6249: <tt>Set</tt>.</p>
6250: <ul>
1.30 cvs 6251: <li><tt>Rank of ElemID</tt> indicates that the counter's value is the rank
6252: of the element of type <tt>ElemID</tt> which encloses the element for
6253: which the counter is being evaluated. For the purposes of this function,
6254: an element of type <tt>ElemID</tt> is considered to enclose itself. This
6255: function is primarily used when the element of type <tt>ElemID</tt> is
6256: part of an aggregate or list, in which case the counter's value is the
6257: element's rank in its list or aggregate. Note that, unlike the
6258: <tt>Rank</tt> function for presentation schemas, the <tt>Page</tt> keyword
6259: cannot be used in place of the <tt>ElemID</tt>.
6260: <p>The type name <tt>ElemID</tt> can be followed by an integer. That
6261: number represents the relative level, among the ancestors of the concerned
6262: element, of the element whose rank is asked. If that relative level
6263: <i>n</i> is unsigned, the <i>n<sup>th</sup></i> element of type
6264: <tt>ElemID</tt> encountered when travelling the logical structure from the
6265: root to the concerned element is taken into account. If the relative
6266: level is negative, the logical structure is travelled in the other
6267: direction, from the concerned element to the root.</p>
6268: </li>
6269: <li><tt>Rlevel of ElemID</tt> indicates that the counter's values is the
6270: relative level in the tree of the element for which the counter is being
6271: evaluated. The counter counts the number of elements of type
6272: <tt>ElemID</tt> which are found on the path between the root of the
6273: document's logical structure tree and the element (inclusive).</li>
6274: <li><tt>Set n on Type1 Add m on Type2</tt> indicates that the counter's
6275: value is calculated as follows: in traversing the document from the
6276: beginning to the element for which the counter is being evaluated, the
6277: counter is set to the value <tt>n</tt> each time a <tt>Type1</tt> element
6278: is encountered and is incremented by the amount <tt>m</tt> each time a
6279: <tt>Type2</tt> element is encountered. The initial value <tt>n</tt> and
6280: the increment <tt>m</tt> are integers.</li>
6281: </ul>
6282:
6283: <p>As in a presentation schema, the <tt>Rank</tt> and <tt>Set</tt> functions
6284: can be modified by a numeric attribute which changes their initial value. This
6285: is indicated by the <tt>Init</tt> keyword followed by the numeric attribute's
1.18 cvs 6286: name. The <tt>Set</tt> function takes the value of the attribute instead of
6287: the <tt>InitValue</tt> (<tt>n</tt>). For the <tt>Rank</tt> function, the
1.1 cvs 6288: value of the attribute is considered to be the rank of the first element of
6289: the list (rather than the normal value of 1). Subsequent items in the list
6290: have their ranks shifted accordingly. In both cases, the attribute must be
1.18 cvs 6291: numeric and must be a local attribute of the root of the document itself.</p>
1.30 cvs 6292: <pre> CounterSeq = Counter < Counter > .
1.1 cvs 6293: Counter = CounterID [ ':' CounterFunc ] ';' .
6294: CounterID = NAME .
6295: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
6296: [ 'Init' AttrID ] /
6297: 'Rlevel' 'of' ElemID /
6298: 'Set' InitValue 'On' ElemID
6299: 'Add' Increment 'On' ElemID
6300: [ 'Init' AttrID ] .
6301: SLevelAsc = [ '-' ] LevelAsc .
6302: LevelAsc = NUMBER .
6303: InitValue = NUMBER .
6304: Increment = NUMBER .
6305: ElemID = NAME .
1.18 cvs 6306: AttrID = NAME .</pre>
1.30 cvs 6307:
1.18 cvs 6308: <blockquote class="example">
1.30 cvs 6309: <p><strong>Example:</strong></p>
6310:
6311: <p>If the body of a chapter is defined in the structure schema by:</p>
6312: <pre>Chapter_Body = LIST OF
1.1 cvs 6313: (Section = BEGIN
6314: Section_Title = Text;
6315: Section_Body = BEGIN
6316: Paragraphs;
6317: Section;
6318: END;
6319: END
1.18 cvs 6320: );</pre>
1.30 cvs 6321:
6322: <p>(sections are defined recursively), a counter can be defined giving the
6323: <a name="sectnum">number of a section</a> within its level in the
6324: hierarchy:</p>
6325: <pre>COUNTERS
1.18 cvs 6326: SectionNumber : Rank of Section;</pre>
1.30 cvs 6327:
6328: <p>A counter holding the hierarchic level of a section:</p>
6329: <pre> SectionLevel : Rlevel of Section;</pre>
6330:
6331: <p>A <a name="uniquenum">counter</a> which sequentially numbers all the
6332: document's sections, whatever their hierarchic level:</p>
6333: <pre> UniqueSectNum : Set 0 on Document Add 1 on Section;</pre>
1.18 cvs 6334: </blockquote>
6335: </div>
1.1 cvs 6336:
1.18 cvs 6337: <div class="subsection">
1.30 cvs 6338: <h3><a name="sectc525">Constants</a></h3>
1.1 cvs 6339:
1.30 cvs 6340: <p>A common feature of translation rules is the generation of constant text.
6341: This text can be defined in the rule that generates it (see for example the <a
1.18 cvs 6342: href="#sectc5210"><tt>Create</tt></a> and <a
6343: href="#sectc5211"><tt>Write</tt></a> rules); but it can also be defined once
6344: in the constant declaration section and used many times in different rules.
6345: The latter option is preferable when the same text is used in several rules or
6346: several <a href="#sectc526">variables</a>.</p>
1.30 cvs 6347:
6348: <p>The <tt>CONST</tt> keyword begins the constant declaration section of the
1.1 cvs 6349: translation schema. It must be omitted if no constants are declared. Each
6350: constant declaration is composed of the constant name, an equals sign, and the
6351: constant's value, which is a character string between apostrophes. A constant
1.18 cvs 6352: declaration is terminated by a semicolon.</p>
1.30 cvs 6353: <pre> ConstSeq = Const < Const > .
1.1 cvs 6354: Const = ConstID '=' ConstValue ';' .
6355: ConstID = NAME .
1.18 cvs 6356: ConstValue = STRING .</pre>
1.30 cvs 6357:
1.18 cvs 6358: <blockquote class="example">
1.30 cvs 6359: <p><strong><a name="levelexample">Example:</a></strong></p>
6360:
6361: <p>The following rule assigns the name <tt>TxtLevel</tt> to the character
6362: string ``Level'':</p>
6363: <pre>CONST
1.18 cvs 6364: TxtLevel = 'Level';</pre>
6365: </blockquote>
6366: </div>
1.1 cvs 6367:
1.18 cvs 6368: <div class="subsection">
1.30 cvs 6369: <h3><a name="sectc526">Variables</a></h3>
1.1 cvs 6370:
1.30 cvs 6371: <p>Variables allow to define variable text which is generated by the
1.18 cvs 6372: <tt>Create</tt> and <tt>Write</tt> rules. They are also used to define file
6373: names which are used in the <tt>Create</tt>, <tt>ChangeMainFile</tt>,
6374: <tt>RemoveFile</tt>, and <tt>Indent</tt> rules. Variables can be defined
6375: either in the <tt>VAR</tt> section of the translation schema or directly in
6376: the rules which use them. Variables that define file names must be declared
6377: in the <tt>VAR</tt> section, and when the same variable is used several times
6378: in the translation schema, it makes sense to define it globally in the
6379: <tt>VAR</tt> section. This section is only present if at least one variable
6380: is defined globally.</p>
1.30 cvs 6381:
6382: <p>After the <tt>VAR</tt> keyword, each global variable is defined by its
6383: name, a colon separator and a sequence of functions (at least one function).
6384: Each variable definition is terminated by a semicolon. Functions determine the
1.1 cvs 6385: different parts which together give the value of the variable. The value is
6386: obtained by concatenating the strings produced by each of the functions. Seven
6387: types of functions are available. Each variable definition may use any number
1.18 cvs 6388: of functions of each type.</p>
6389: <ul>
1.30 cvs 6390: <li>The function <tt>Value(Counter)</tt>returns a string representing the
6391: value taken by the counter when it is evaluated for the element in whose
6392: rule the variable is used. The counter must have been declared in the
6393: <tt>COUNTERS</tt> section of the translation schema. When the counter is
6394: expressed in arabic numerals, the counter name can be followed by a colon
6395: and an integer indicating a minimum length (number of characters) for the
6396: string; if the counter's value is normally expressed with fewer characters
6397: than the required minimum, zeroes are added to the front of the string to
6398: achieve the minimum length.
6399: <p>By default, the counter value is written in arabic digits. If another
6400: representation of that value is needed, the counter name must be followed
6401: by a comma and one of the following keywords:</p>
6402: <ul>
6403: <li><tt>Arabic</tt>: arabic numerals (default value),</li>
6404: <li><tt>LRoman</tt>: lower-case roman numerals,</li>
6405: <li><tt>URoman</tt>: upper-case roman numerals,</li>
6406: <li><tt>Uppercase</tt>: upper-case letter,</li>
6407: <li><tt>Lowercase</tt>: lower-case letter.</li>
6408: </ul>
6409: </li>
6410: <li>The function <tt>FileDir</tt>, without parameter, returns a string
6411: representing the name of the directory of the output file that has been
6412: given as a parameter to the translation program. The string includes a
6413: character '/' at the end.</li>
6414: <li>The function <tt>FileName</tt>, without parameter, returns a string
6415: representing the name of the output file that has been given as a
6416: parameter to the translation program. The file extension (the character
6417: string that terminate the file name, after a dot) is not part of that
6418: string.</li>
6419: <li>The function <tt>Extension</tt>, without parameter, returns a string
6420: representing the extension of the file name. That string is empty if the
6421: file name that has been given as a parameter to the translation program
6422: has no extension. If there is an extension, its first character is a
6423: dot.</li>
6424: <li>The function <tt>DocumentName</tt>, without parameter, returns a string
6425: representing the name of the document being translated.</li>
6426: <li>The function <tt>DocumentDir</tt>, without parameter, returns a string
6427: representing the directory containing the document being translated.</li>
6428: <li>The function formed by the name of a constant returns that constant's
6429: value.</li>
6430: <li>The function formed by a character string between apostrophes returns
6431: that string.</li>
6432: <li>The function formed by the name of a buffer returns the contents of that
6433: buffer. If the named buffer is the picture buffer, then the name of the
6434: last picture encountered is returned. Otherwise, the buffer is a read
1.31 cvs 6435: buffer and the value returned is text previously read from the terminal.
1.30 cvs 6436: If the buffer is empty (no picture has been encountered or the
6437: <tt>Read</tt> rule has not been executed for the buffer), then the empty
6438: string is returned.</li>
6439: <li>The function formed by an attribute name takes the value of the
6440: indicated attribute for the element to which the variable applies. If the
6441: element does not have that attribute, then the element's ancestor are
6442: searched toward the root of the tree. If one of the ancestors does have
6443: the attribute then its value is used. If no ancestors have the attribute,
6444: then the value of the function is the empty string.</li>
1.18 cvs 6445: </ul>
1.30 cvs 6446: <pre> VariableSeq = Variable < Variable > .
6447: Variable = VarID ':' Function < Function > ';' .
1.1 cvs 6448: VarID = NAME .
6449: Function ='Value' '(' CounterID [ ':' Length ]
6450: [ ',' CounterStyle ] ')' /
6451: 'FileDir' / 'FileName' / 'Extension' /
6452: 'DocumentName' / 'DocumentDir' /
6453: ConstID / CharString /
6454: BufferID / AttrID .
6455: Length = NUMBER .
6456: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
6457: 'Uppercase' / 'Lowercase' .
1.18 cvs 6458: CharString = STRING .</pre>
1.30 cvs 6459:
1.18 cvs 6460: <blockquote class="example">
1.30 cvs 6461: <p><strong>Example:</strong></p>
6462:
6463: <p>To create, at the beginning of each section of the translated document,
6464: text composed of the string ``Section'' followed by the section number, the
6465: following <a name="varsectexample">variable definition</a> might be
6466: used:</p>
6467: <pre>VAR
1.18 cvs 6468: SectionVar : 'Section' Value(SectionNumber);</pre>
1.30 cvs 6469:
6470: <p>(see the definition of <a
6471: href="#sectnum"><tt>SectionNumber</tt></a>).</p>
6472:
6473: <p>The following variable definition can be used to create, at the beginning
6474: of each section, the text ``Level'' followed by the hierarchical level of
6475: the section. It used the constant defined above.</p>
6476: <pre> LevelVar : TxtLevel Value(SectionLevel);</pre>
6477:
6478: <p>(see the definitions of <a href="#sectnum"><tt>SectionLevel</tt></a> and
6479: of <a href="#levelexample"><tt>TxtLevel</tt></a>).</p>
6480:
6481: <p>To generate the translation of each section in a different file (see <a
6482: href="#sectc5220">rule <tt>ChangeMainFile</tt></a>), the name of these files
6483: might be defined by the following variable:</p>
6484: <pre> VarOutpuFile : FileName Value(SectionNumber)
1.18 cvs 6485: Extension;</pre>
1.30 cvs 6486:
6487: <p>If <tt>output.txt</tt> is the name of the <a name="varoutputfile">output
6488: file</a> specified when starting the translation program, translated
6489: sections are written in files <tt>output1.txt</tt>, <tt>output2.txt</tt>,
6490: etc.</p>
1.18 cvs 6491: </blockquote>
6492: </div>
6493:
6494: <div class="subsection">
1.30 cvs 6495: <h3><a name="sectc527">Translating structure elements</a></h3>
1.18 cvs 6496:
1.30 cvs 6497: <p>The <tt>RULES</tt> keyword introduces the translation rules which will be
1.1 cvs 6498: applied to the various structured element types. Translation rules can be
6499: specified for each element type defined in the structure schema, including the
1.18 cvs 6500: base types defined implicitly, whose names are <tt>TEXT_UNIT</tt>,
6501: <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>, <tt>GRAPHIC_UNIT</tt> and
6502: <tt>PAGE_UNIT</tt>. But it is not necessary to specify rules for every
6503: defined type.</p>
1.30 cvs 6504:
6505: <p>If there are no translation rules for an element type, the elements that it
1.1 cvs 6506: contains (and which may have rules themselves) will still be translated, but
6507: the translator will produce nothing for the element itself. To make the
1.18 cvs 6508: translator completely ignore the content of an element the <a
6509: href="#sectc5217"><tt>Remove</tt> rule</a> must be used.</p>
1.30 cvs 6510:
6511: <p>The translation rules for an element type defined in the structure schema
6512: are written using the name of the type followed by a colon and the list of
1.18 cvs 6513: applicable rules. When the element type is a <a href="#sectd3285">mark
6514: pair</a>, but only in this case, the type name must be preceded by the
6515: <tt>First</tt> or <tt>Second</tt> keyword. This keyword indicates whether the
6516: rules that follow apply to the first or second mark of the pair.</p>
1.30 cvs 6517:
6518: <p>The list of rules can take several forms. It may be a simple
6519: non-conditional rule. It can also be formed by a condition followed by one or
6520: more simple rules. Or it can be a block of rules beginning with the
6521: <tt>BEGIN</tt> keyword and ending with the <tt>END</tt> keyword and a
6522: semicolon. This block of rules can contain one or more simple rules and/or
6523: one or more conditions, each followed by one or more simple rules.</p>
6524: <pre> ElemSeq = TransType < TransType > .
1.1 cvs 6525: TransType = [ FirstSec ] ElemID ':' RuleSeq .
6526: FirstSec = 'First' / 'Second' .
1.30 cvs 6527: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
1.1 cvs 6528: Rule = SimpleRule / ConditionBlock .
6529: ConditionBlock = 'IF' ConditionSeq SimpleRuleSeq .
1.30 cvs 6530: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.18 cvs 6531: SimpleRule .</pre>
6532: </div>
1.1 cvs 6533:
1.18 cvs 6534: <div class="subsection">
1.30 cvs 6535: <h3><a name="sectc528">Conditional rules</a></h3>
1.1 cvs 6536:
1.30 cvs 6537: <p>In a translation schema, the translation rules are either associated with
1.1 cvs 6538: element types or with attribute values or with a specific presentation. They
6539: are applied by the translator each time an element of the corresponding type
6540: is encountered in the translated document or each time the attribute value is
6541: carried by an element or also, each time the specific translation is attached
6542: to an element. This systematic application of the rules can be relaxed: it is
6543: possible to add a condition to one or more rules, so that these rules are only
1.18 cvs 6544: applied when the condition is true.</p>
1.30 cvs 6545:
6546: <p>A condition begins with the keyword <tt>IF</tt>, followed by a sequence of
1.1 cvs 6547: elementary conditions. Elementary conditions are separated from each other by
1.18 cvs 6548: the <tt>AND</tt> keyword. If there is only one elementary condition, this
1.1 cvs 6549: keyword is absent. The rules are only applied if all the elementary
6550: conditions are true. The elementary condition can be negative; it is then
1.18 cvs 6551: preceded by the <tt>NOT</tt> keyword.</p>
1.30 cvs 6552:
6553: <p>When the translation rule(s) controlled by the condition apply to a
6554: reference element or a reference attribute, an elementary condition can also
6555: apply to element referred by this reference. The <tt>Target</tt> keyword is
6556: used for that purpose. It must appear before the keyword defining the
6557: condition type.</p>
6558:
6559: <p>Depending on their type, some conditions may apply either to the element
6560: with which they are associated, or to one of its ancestor. In the case of an
1.18 cvs 6561: ancestor, the key word <tt>Ancestor</tt> must be used, followed by</p>
6562: <ul>
1.30 cvs 6563: <li>either an integer which represents the number of levels in the tree
6564: between the element and the ancestor of interest,</li>
6565: <li>or the type name of the ancestor of interest. If that type is defined
6566: in a separate structure schema, the name of that schema must follow
6567: between parentheses.</li>
1.18 cvs 6568: </ul>
1.30 cvs 6569:
6570: <p>There is a special case for the parent element, which can be simply written
1.18 cvs 6571: <tt>Parent</tt> instead of <tt>Ancestor 1</tt>.</p>
1.30 cvs 6572:
6573: <p>Only conditions <tt>First</tt>, <tt>Last</tt>, <tt>Referred</tt>,
1.18 cvs 6574: <tt>Within</tt>, <tt>Attributes</tt>, <tt>Presentation</tt>, <tt>Comment</tt>
1.1 cvs 6575: and those concerning an attribute or a specific presentation can apply to an
1.18 cvs 6576: ancestor. Conditions <tt>Defined</tt>, <tt>FirstRef</tt>, <tt>LastRef</tt>,
6577: <tt>ExternalRef</tt>, <tt>Alphabet</tt>, <tt>FirstAttr</tt>,
6578: <tt>LastAttr</tt>, <tt>ComputedPage</tt>, <tt>StartPage</tt>,
6579: <tt>UserPage</tt>, <tt>ReminderPage</tt>, <tt>Empty</tt> cannot be preceded by
6580: keywords <tt>Parent</tt> or <tt>Ancestor</tt>.</p>
1.30 cvs 6581:
6582: <p>In condition <tt>Referred</tt> and in the condition that applies to a named
1.18 cvs 6583: attribute, a symbol '<tt>*</tt>' can indicate that the condition is related
1.5 cvs 6584: only to the element itself. If this symbol is not present, not only the
1.18 cvs 6585: element is considered, but also its ancestor, at any level.</p>
1.30 cvs 6586:
6587: <p>The form of an elementary condition varies according to the type of
1.18 cvs 6588: condition.</p>
1.1 cvs 6589:
1.18 cvs 6590: <div class="subsubsection">
6591: <h4><a name="sectd5281">Conditions based on the logical position of the
6592: element</a></h4>
1.30 cvs 6593:
6594: <p>The condition can be on the position of the element in the document's
6595: logical structure tree. It is possible to test whether the element is the
6596: first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
6597: not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>).</p>
6598:
6599: <p>It is also possible to test if the element is contained in an element of a
1.18 cvs 6600: given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). If that
1.1 cvs 6601: element type is defined in a structure schema which is not the one which
6602: corresponds to the translation schema, the type name of this element must be
6603: followed, between parentheses, by the name of the structure schema which
1.18 cvs 6604: defines it.</p>
1.30 cvs 6605:
6606: <p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
1.18 cvs 6607: condition is satisfied only if the <em>parent</em> element has the type
6608: indicated. If the word <tt>Immediately</tt> is missing, the condition is
6609: satisfied if any <em>ancestor</em> has the type indicated.</p>
1.30 cvs 6610:
6611: <p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
1.1 cvs 6612: type. It specifies the number of ancestors of the indicated type that must be
6613: present for the condition to be satisfied. If the keyword
1.18 cvs 6614: <tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
6615: element must have the indicated type. The integer <i>n</i> must be positive
1.30 cvs 6616: or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
1.1 cvs 6617: maximum or minimum number of ancestors. If these symbols are missing, the
1.18 cvs 6618: condition is satisfied only if it exists exactly <i>n</i> ancestors. When
1.30 cvs 6619: this number is missing, it is equivalent to > 0.</p>
6620:
6621: <p>If the condition applies to translation rules associated with an attribute,
1.18 cvs 6622: i.e. if it is in the <tt>ATTRIBUTES</tt> section of the presentation schema,
1.11 cvs 6623: the condition can be simply an element name. Translation rules are then
1.18 cvs 6624: executed only if the attribute is attached to an element of that type. The
6625: keyword <tt>NOT</tt> before the element name indicates that the translation
6626: rules must be executed only if the element is not of the type indicated.</p>
6627: </div>
1.1 cvs 6628:
1.18 cvs 6629: <div class="subsubsection">
1.30 cvs 6630: <h4><a name="sectd5282">Conditions on references</a></h4>
1.1 cvs 6631:
1.30 cvs 6632: <p>References may be taken into account in conditions, which can be based on
6633: the fact that the element, or one of its ancestors (unless symbol <tt>*</tt>
6634: is present), is designated by a at least one reference (<tt>Referred</tt>) or
6635: by none (<tt>NOT Referred</tt>). If the element or attribute to which the
1.1 cvs 6636: condition is attached is a reference, the condition can be based on the fact
6637: that it acts as the first reference to the designated element
1.18 cvs 6638: (<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>), or as a reference to
6639: an element located in another document (<tt>ExternalRef</tt>). Like all
6640: conditions, conditions on references can be inverted by the <tt>NOT</tt>
6641: keyword.</p>
6642: </div>
6643:
6644: <div class="subsubsection">
1.30 cvs 6645: <h4><a name="sectd5283">Conditions on the parameters</a></h4>
1.18 cvs 6646:
1.30 cvs 6647: <p>Elements which are <a href="#sectc326">parameters</a> can be given a
1.18 cvs 6648: particular condition which is based on whether or not the parameter is given a
6649: value in the document (<tt>Defined</tt> or <tt>NOT Defined</tt>,
6650: respectively).</p>
6651: </div>
1.1 cvs 6652:
1.18 cvs 6653: <div class="subsubsection">
1.30 cvs 6654: <h4><a name="sectd5284">Conditions on the alphabets</a></h4>
1.1 cvs 6655:
1.30 cvs 6656: <p>The character string base type (and only this type) can use the condition
1.18 cvs 6657: <tt>Alphabet = a</tt> which indicates that the translation rule(s) should only
1.1 cvs 6658: apply if the alphabet of the character string is the one whose name appears
1.18 cvs 6659: after the equals sign (or is not, if there is a preceding <tt>NOT</tt>
1.1 cvs 6660: keyword). This condition cannot be applied to translation rules of an
1.18 cvs 6661: attribute.</p>
1.30 cvs 6662:
6663: <p>In the current implementation of Thot, the available alphabets are the
1.18 cvs 6664: <tt>Latin</tt> alphabet and the <tt>Greek</tt> alphabet.</p>
6665: </div>
1.1 cvs 6666:
1.18 cvs 6667: <div class="subsubsection">
1.30 cvs 6668: <h4><a name="sectd5285">Conditions on page breaks</a></h4>
1.1 cvs 6669:
1.30 cvs 6670: <p>The page break base type (and only this type) can use the following
1.18 cvs 6671: conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>, and
6672: <tt>ReminderPage</tt>. The <tt>ComputedPage</tt> condition indicates that the
1.1 cvs 6673: translation rule(s) should apply if the page break was created automatically
1.18 cvs 6674: by Thot; the <tt>StartPage</tt> condition is true if the page break is
6675: generated before the element by the <tt>Page</tt> rule of the P language; the
6676: <tt>UserPage</tt> condition applies if the page break was inserted by the
6677: user; and the <tt>ReminderPage</tt> is applied if the page break is a reminder
6678: of page breaking.</p>
6679: </div>
1.1 cvs 6680:
1.18 cvs 6681: <div class="subsubsection">
1.30 cvs 6682: <h4><a name="sectd5286">Conditions on the element's content</a></h4>
1.1 cvs 6683:
1.30 cvs 6684: <p>The condition can be based on whether or not the element is empty. An
6685: element which has no children or whose leaves are all empty is considered to
6686: be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
6687: optionally preceded by the <tt>NOT</tt> keyword.</p>
1.18 cvs 6688: </div>
1.1 cvs 6689:
1.18 cvs 6690: <div class="subsubsection">
1.30 cvs 6691: <h4><a name="sectd5287">Conditions on the presence of comments</a></h4>
1.1 cvs 6692:
1.30 cvs 6693: <p>The condition can be based on the presence or absence of comments
6694: associated with the translated element. This condition is expressed by the
6695: keyword <tt>Comment</tt>, optionally preceded by the keyword <tt>NOT</tt>.</p>
1.18 cvs 6696: </div>
1.1 cvs 6697:
1.18 cvs 6698: <div class="subsubsection">
6699: <h4><a name="sectd5288">Conditions on the presence of specific presentation
6700: rules</a></h4>
1.30 cvs 6701:
6702: <p>The condition can be based on the presence or absence of specific
6703: presentation rules associated with the translated element, whatever the rules,
6704: their value or their number. This condition is expressed by the keyword
1.18 cvs 6705: <tt>Presentation</tt>, optionally preceded by the <tt>NOT</tt> keyword.</p>
6706: </div>
1.1 cvs 6707:
1.18 cvs 6708: <div class="subsubsection">
6709: <h4><a name="sectd5289">Conditions on the presence of logical
6710: attributes</a></h4>
1.30 cvs 6711:
6712: <p>In the same way, the condition can be based on the presence or absence of
1.1 cvs 6713: attributes associated with the translated elements, no matter what the
1.18 cvs 6714: attributes or their values. The <tt>Attributes</tt> keyword expresses this
6715: condition.</p>
6716: </div>
1.1 cvs 6717:
1.18 cvs 6718: <div class="subsubsection">
1.30 cvs 6719: <h4><a name="sectd52810">Conditions on logical attributes</a></h4>
1.1 cvs 6720:
1.30 cvs 6721: <p>If the condition appears in the translation rules of an attribute, the
1.18 cvs 6722: <tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
1.1 cvs 6723: the rules must only be applied if this attribute is the first attribute for
6724: the translated element or if it is the last (respectively). These conditions
1.18 cvs 6725: can also be inverted by the <tt>NOT</tt> keyword.</p>
1.30 cvs 6726:
6727: <p>Another type of condition can only be applied to the translation rules when
1.18 cvs 6728: the element being processed (or one of its ancestors if symbol <tt>*</tt> is
1.1 cvs 6729: missing) has a certain attribute, perhaps with a certain value or, in
6730: contrast, when the element does not have this attribute with this value. The
6731: condition is specified by writing the name of the attribute after the keyword
1.18 cvs 6732: <tt>IF</tt> or <tt>AND</tt>. The <tt>NOT</tt> keyword can be used to invert
1.1 cvs 6733: the condition. If the translation rules must be applied to any element which
6734: has this attribute (or does not have it, if the condition is inverted) no
6735: matter what the attribute's value, the condition is complete. If, in
6736: contrast, the condition applies to one or more values of the attribute, these
6737: are indicated after the name of the attribute, except for reference attributes
1.18 cvs 6738: which do not have values.</p>
1.30 cvs 6739:
6740: <p>The representation of the values of an <a name="relattr">attribute</a> in a
1.1 cvs 6741: condition depends on the attribute's type. For attributes with enumerated or
6742: textual types, the value (a name or character string between apostrophes,
6743: respectively) is simply preceded by an equals sign. For numeric attributes,
6744: the condition can be based on a single value or on a range of values. In the
6745: case of a unique value, this value (an integer) is simply preceded by an
1.18 cvs 6746: equals sign. Conditions based on ranges of values have several forms:</p>
6747: <ul>
1.30 cvs 6748: <li>all values less than a given value (the value is preceded by a ``less
6749: than'' sign).</li>
6750: <li>all values greater than a given value (the value is preceded by a
6751: ``greater than'' sign).</li>
6752: <li>all values falling in an interval, bounds included. The range of values
6753: is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
6754: Minimum and Maximum are integers.</li>
1.18 cvs 6755: </ul>
1.30 cvs 6756:
6757: <p>All numeric values may be negative. The integer is simply preceded by a
6758: minus sign.</p>
6759:
6760: <p>Both local and global attributes can be used in conditions.</p>
1.18 cvs 6761: </div>
1.1 cvs 6762:
1.18 cvs 6763: <div class="subsubsection">
1.30 cvs 6764: <h4><a name="sectd52811">Conditions on specific presentation rules</a></h4>
1.1 cvs 6765:
1.30 cvs 6766: <p>It is possible to apply translation rules only when the element being
1.1 cvs 6767: processed has or does not have a specific presentation rule, possibly with a
6768: certain value. The condition is specified by writing the name of the
1.18 cvs 6769: presentation rule after the keyword <tt>IF</tt> or <tt>AND</tt>. The
6770: <tt>NOT</tt> keyword can be used to invert the condition. If the translation
1.1 cvs 6771: rules must be applied to any element which has this presentation rule (or does
6772: not have it, if the condition is inverted) no matter what the rule's value,
6773: the condition is complete. If, in contrast, the condition applies to one or
6774: more values of the rule, these are indicated after the name of the
1.18 cvs 6775: attribute.</p>
1.30 cvs 6776:
6777: <p>The representation of presentation rule values in a condition is similar to
1.1 cvs 6778: that for attribute values. The representation of these values depend on the
6779: type of the presentation rule. There are three categories of presentation
1.18 cvs 6780: rules:</p>
6781: <ul>
1.30 cvs 6782: <li>those taking numeric values (<tt>Size, Indent, LineSpacing,
6783: LineWeight</tt>),</li>
6784: <li>those with values taken from a predefined list (<tt>Adjust, Justify,
6785: Hyphenate, Style, Weight, Font, UnderLine, Thickness,
6786: LineStyle</tt>),</li>
6787: <li>those whose value is a name (<tt>FillPattern, Background,
6788: Foreground</tt>).</li>
1.18 cvs 6789: </ul>
1.30 cvs 6790:
6791: <p>For presentation rules which take numeric values, the condition can take a
1.1 cvs 6792: unique value or a range of values. In the case of a unique value, this value
6793: (an integer) is simply preceded by an equals sign. Conditions based on ranges
1.18 cvs 6794: of values have several forms:</p>
6795: <ul>
1.30 cvs 6796: <li>all values less than a given value (the value is preceded by a ``less
6797: than'' sign).</li>
6798: <li>all values greater than a given value (the value is preceded by a
6799: ``greater than'' sign).</li>
6800: <li>all values falling in an interval, bounds included. The range of values
6801: is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
6802: Minimum and Maximum are integers.</li>
1.18 cvs 6803: </ul>
1.30 cvs 6804:
6805: <p>Values for the <tt>Indent</tt>rule may be negative. The integer is then
1.2 cvs 6806: simply preceded by a minus sign and represents how far the first line starts
1.18 cvs 6807: to the left of the other lines.</p>
1.30 cvs 6808:
6809: <p>For presentation rules whose values are taken from predefined lists, the
6810: value which satisfies the condition is indicated by an equals sign followed by
6811: the name of the value.</p>
6812:
6813: <p>For presentation rule whose values are names, the value which satisfies the
1.1 cvs 6814: condition is indicated by the equals sign followed by the value's name. The
1.18 cvs 6815: names of fill patterns (the <tt>FillPattern</tt> rule) and of colors (the
6816: <tt>Foreground</tt> and <tt>Background</tt> rules) known to Thot are the same
6817: as in the P language.</p>
1.30 cvs 6818:
6819: <p>The syntax of conditions based on the specific presentation is the same as
6820: the syntax used to express the <a href="#sectc5224">translation of specific
1.18 cvs 6821: presentation rules</a>.</p>
1.30 cvs 6822:
6823: <p>When a condition has only one rule, the condition is simply followed by
6824: that rule. If it has several rules, they are placed after the condition
6825: between the keywords <tt>BEGIN</tt> and <tt>END</tt>.</p>
1.18 cvs 6826: <pre> ConditionSeq = Condition [ 'AND' Condition ] .
1.1 cvs 6827: Condition = [ 'NOT' ] [ 'Target' ] Cond .
6828: Cond = CondElem / CondAscend .
6829: CondElem ='FirstRef' / 'LastRef' /
6830: 'ExternalRef' /
6831: 'Defined' /
6832: 'Alphabet' '=' Alphabet /
6833: 'ComputedPage' / 'StartPage' /
6834: 'UserPage' / 'ReminderPage' /
6835: 'Empty' /
1.11 cvs 6836: ElemID /
1.1 cvs 6837: 'FirstAttr' / 'LastAttr' .
6838: CondAscend = [ Ascend ] CondOnAscend .
6839: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
6840: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
6841: CondRelLevel = NUMBER .
6842: CondOnAscend ='First' / 'Last' /
6843: 'Referred' /
6844: [ 'Immediately' ] 'Within' [ NumParent ]
6845: ElemID [ ExtStruct ] /
6846: 'Attributes' /
6847: AttrID [ RelatAttr ] /
6848: 'Presentation' /
6849: PresRule /
6850: 'Comment' .
6851: NumParent = [ GreaterLess ] NParent .
1.30 cvs 6852: GreaterLess = '>' / '<' .
1.1 cvs 6853: NParent = NUMBER.
6854: ExtStruct = '(' ElemID ')' .
6855: Alphabet = NAME .
6856: RelatAttr ='=' Value /
1.30 cvs 6857: '>' [ '-' ] Minimum /
1.1 cvs 6858: '<' [ '-' ] Maximum /
6859: 'IN' '[' [ '-' ] MinInterval '..'
6860: [ '-' ] MaxInterval ']' .
6861: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
6862: Minimum = NUMBER .
6863: Maximum = NUMBER .
6864: MinInterval = NUMBER .
6865: MaxInterval = NUMBER .
6866: IntegerVal = NUMBER .
6867: TextVal = STRING .
1.18 cvs 6868: AttrValue = NAME .</pre>
1.30 cvs 6869:
1.18 cvs 6870: <blockquote class="example">
1.30 cvs 6871: <p><strong>Example:</strong></p>
6872:
6873: <p>Suppose that after each element of type Section_Title it is useful to
6874: produce the text <tt>\label{SectX}</tt> where <tt>X</tt> represents the
6875: section number, but only if the section is designated by one or more
6876: references in the document. The following conditional rule produces this
6877: effect:</p>
6878: <pre>RULES
1.1 cvs 6879: Section_Title :
6880: IF Referred
1.18 cvs 6881: Create ('\label{Sect' Value(UniqueSectNum) '}\12') After;</pre>
1.30 cvs 6882:
6883: <p>(the declaration of the <a href="#sectc5224"><tt>UniqueSectNum</tt>
6884: counter</a> is given above). The string <tt>\12</tt> represents a line
6885: break.</p>
1.18 cvs 6886: </blockquote>
1.30 cvs 6887:
1.18 cvs 6888: <blockquote class="example">
1.30 cvs 6889: <p><strong>Example:</strong></p>
6890:
6891: <p>Suppose that for elements of the Elmnt type it would be useful to produce
6892: a character indicating the value of the numeric attribute Level associated
6893: with the element: an ``A'' for all values of Level less than 3, a ``B'' for
6894: values between 3 and 10 and a ``C'' for values greater than 10. This can be
6895: achieved by writing the following rules for the Elmnt type:</p>
6896: <pre>RULES
1.1 cvs 6897: Elmnt :
6898: BEGIN
6899: IF Level < 3
6900: Create 'A';
6901: IF Level IN [3..10]
6902: Create 'B';
1.30 cvs 6903: IF Level > 10
1.1 cvs 6904: Create 'C';
1.18 cvs 6905: END;</pre>
6906: </blockquote>
6907: </div>
6908: </div>
1.1 cvs 6909:
1.18 cvs 6910: <div class="subsection">
1.30 cvs 6911: <h3><a name="sectc529">Translation rules</a></h3>
1.1 cvs 6912:
1.30 cvs 6913: <p>Fifteen types of translation rules can be associated with element types and
1.18 cvs 6914: attribute values. They are the <tt>Create</tt>, <tt>Write</tt>,
6915: <tt>Read</tt>, <tt>Include</tt>, <tt>Get</tt>, <tt>Copy</tt>, <tt>Use</tt>,
1.31 cvs 6916: <tt>Remove</tt>, <tt>Ignore</tt>, <tt>NoTranslation</tt>,
6917: <tt>NoLineBreak</tt>, <tt>ChangeMainFile</tt>, <tt>RemoveFile</tt>,
6918: <tt>Set</tt>, <tt>Add</tt>, <tt>Indent</tt>, rules. Each rule has its own
6919: syntax, although they are all based on very similar models.</p>
1.18 cvs 6920: <pre> SimpleRule = 'Create' [ 'IN' VarID ] Object
1.1 cvs 6921: [ Position ] ';' /
6922: 'Write' Object [ Position ] ';' /
6923: 'Read' BufferID [ Position ] ';' /
6924: 'Include' File [ Position ] ';' /
6925: 'Get' [ RelPosition ] ElemID
6926: [ ExtStruct ]
6927: [ Position ] ';' /
6928: 'Copy' [ RelPosition ] ElemID
6929: [ ExtStruct ]
6930: [ Position ] ';' /
6931: 'Use' TrSchema [ 'For' ElemID ] ';' /
6932: 'Remove' ';' /
1.31 cvs 6933: 'Ignore' ';' /
1.1 cvs 6934: 'NoTranslation' ';' /
6935: 'NoLineBreak' ';' /
6936: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 6937: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 6938: 'Set' CounterID InitValue [ Position ] ';' /
6939: 'Add' CounterID Increment [ Position ] ';' /
1.25 cvs 6940: 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .</pre>
1.18 cvs 6941: </div>
6942:
6943: <div class="subsection">
1.30 cvs 6944: <h3><a name="sectc5210">The <tt>Create</tt> rule</a></h3>
1.18 cvs 6945:
1.30 cvs 6946: <p>The most frequently used rule is undoubtedly the <tt>Create</tt> rule,
6947: which generates fixed or variable text (called an <em>object</em>) in the
6948: output file. The generated text can be made to appear either before or after
6949: the content of the element to which the rule applies. The rule begins with the
1.18 cvs 6950: <tt>Create</tt> keyword, followed by a specifier for the object and a keyword
6951: (<tt>Before</tt> or <tt>After</tt>) indicating the position of the generated
6952: text (<a href="#sectc5222">before or after</a> the element's content). If the
1.1 cvs 6953: position is not indicated, the object will be generated before the element's
6954: content. This rule, like all translation rules, is terminated by a
1.18 cvs 6955: semicolon.</p>
1.30 cvs 6956:
6957: <p>The <tt>Create</tt> keyword can be followed by the <tt>IN</tt> keyword and
6958: by the name of a variable. This means that the text generated by the rule
6959: must not be written in the main output file, but in the file whose name is
1.18 cvs 6960: specified by the variable.</p>
1.30 cvs 6961:
6962: <p>This allows the translation program to generate text in different files
6963: during the same run. These files do not need to be explicitely declared or
6964: opened. They do not need to be closed either, but if they contain temporary
6965: data, they can be removed (see the <a href="#sectc5220a"><tt>RemoveFile</tt>
6966: rule</a>). As soon as the translation program executes a <tt>Create</tt> rule
6967: for a file that is not yet open, it opens the file. These files are closed
6968: when the translation is finished.</p>
1.18 cvs 6969: <pre> 'Create' [ 'IN' VarID ] Object
1.1 cvs 6970: [ Position ] ';'
6971: Object = ConstID / CharString /
6972: BufferID /
6973: VarID /
1.30 cvs 6974: '(' Function < Function > ')' /
1.21 cvs 6975: [ 'Translated' ] AttrID /
1.1 cvs 6976: 'Value' /
6977: 'Content' /
6978: 'Comment' /
6979: 'Attributes' /
6980: 'Presentation' /
6981: 'RefId' /
6982: 'PairId' /
6983: 'FileDir' /
6984: 'FileName' /
6985: 'Extension' /
6986: 'DocumentName' /
6987: 'DocumentDir' /
6988: [ 'Referred' ] ReferredObject .
6989: Position ='After' / 'Before' .
6990:
6991: ReferredObject = VarID /
6992: ElemID [ ExtStruct ] /
6993: 'RefId' /
6994: 'DocumentName' /
1.18 cvs 6995: 'DocumentDir' .</pre>
1.30 cvs 6996:
6997: <p>The object to be generated can be:</p>
1.18 cvs 6998: <ul>
1.30 cvs 6999: <li>a constant string, specified by its name if it is declared in the
7000: schema's <tt>CONST</tt> section, or given directly as a value between
7001: apostrophes;</li>
7002: <li>the contents of a buffer, designated by the name of the buffer;</li>
7003: <li>a variable, designated by its name if it is declared in the translation
7004: schema's <tt>VAR</tt> section, or given directly between parentheses. The
7005: text generated is the value of that variable evaluated for the element to
7006: which the rule applies.</li>
7007: <li>the value of an attribute, if the element being translated has this
7008: attribute. The attribute is specified by its name. If it's a text
7009: attribute, it can be preceded by the <code>Translated</code> keyword,
7010: which causes the attribute value to be recoded using the text translation
7011: table defined by section <code><a
7012: href="#sectc5225">TEXTTRANSLATE</a></code>;</li>
7013: <li>the value of a specific presentation rule. This object can only be
7014: generated if the translation rule is for a <a href="#prestransl">specific
7015: presentation rule</a>. It is specified by the <tt>Value</tt>
7016: keyword;</li>
7017: <li>the element's content. That is, the content of the leaves of the
7018: subtree of the translated element. This is specified by the
7019: <tt>Content</tt> keyword;</li>
7020: <li>the comment attached to the element. When the element doesn't have a
7021: comment, nothing is generated. This is indicated by the <tt>Comment</tt>
7022: keyword;</li>
7023: <li>the translation of all attributes of the element (which is primarily
7024: used to apply the attribute translation rules <a
7025: href="#sectc5222">before</a> those of the element type). This is
7026: specified by the <tt>Attributes</tt> keyword.</li>
7027: <li>the translation of all of the element's specific presentation rules
7028: (which is primarily used to apply the translation rules for the specific
7029: presentation rules <a href="#sectc5222">before</a> those of the element or
7030: its attributes). This option is specified by the <tt>Presentation</tt>
7031: keyword;</li>
7032: <li>The value of the reference's identifier.<br>
7033: Thot associates a unique identifier with each element in a document. This
7034: identifier (called <em>reference's identifier</em> or <em>label</em>) is a
7035: character string containing the letter `L' followed by digits. Thot uses
7036: it in references for identifying the referred element.<br>
7037: The <tt>RefId</tt> keyword produces the reference's identifier of the
7038: element to which the translation rule is applied, or the reference's
7039: identifier of its first ancestor that is referred by a reference or that
7040: can be referred by a reference.</li>
7041: <li>the value of a mark pair's unique identifier. This may only be used for
7042: <a href="#sectd3285">mark pairs</a> and is indicated by the
7043: <tt>PairId</tt> keyword.</li>
7044: <li>the directory containing the file being generated (this string includes
7045: an ending '/', if it is not empty). This is indicated by the
7046: <tt>FileDir</tt> keyword.</li>
7047: <li>the name of the file being generated (only the name, without the
7048: directory and without the extension). This is indicated by the
7049: <tt>FileName</tt> keyword.</li>
7050: <li>the extension of the file being generated (this string starts with a
7051: dot, if it is not empty). This is indicated by the <tt>Extension</tt>
7052: keyword.</li>
7053: <li>the name of the document being translated. This is indicated by the
7054: <tt>DocumentName</tt> keyword.</li>
7055: <li>the directory containing the document being translated. This is
7056: indicated by the <tt>DocumentDir</tt> keyword.</li>
1.18 cvs 7057: </ul>
1.30 cvs 7058:
7059: <p>When the rule applies to a reference (an element or an attribute defined as
7060: a reference in the structure schema), it can generate a text related to the
1.21 cvs 7061: element referred by that reference. The rule name is then followed by the
1.18 cvs 7062: <tt>Referred</tt> keyword and a specification of the object to be generated
7063: for the referred element. This specification can be:</p>
7064: <ul>
1.30 cvs 7065: <li>the name of a variable. The rule generates the value of that variable,
7066: computed for the referred element.</li>
7067: <li>an element type. The rule generates the translation of the element of
7068: that type, which is in the subtree of the referred element. If this
7069: element is not defined in the structure schema which corresponds to the
7070: translation schema (that is, an object defined in another schema), the
7071: element's type name must be followed by the name of its structure schema
7072: between parentheses.</li>
7073: <li>the <tt>RefId</tt> keyword. The rule generates the reference's
7074: identifier of the referred element.</li>
7075: <li>the <tt>DocumentName</tt> keyword. The rule generates the name of the
7076: document to which the referred element belongs.</li>
7077: <li>the <tt>DocumentDir</tt> keyword. The rule generates the name of the
7078: directory that contains the document of the referred element.</li>
1.18 cvs 7079: </ul>
7080: </div>
1.1 cvs 7081:
1.18 cvs 7082: <div class="subsection">
1.30 cvs 7083: <h3><a name="sectc5211">The <tt>Write</tt> rule</a></h3>
1.1 cvs 7084:
1.30 cvs 7085: <p>The <tt>Write</tt> has the same syntax as the <tt>Create</tt> rule. It
7086: also produces the same effect, but the generated text is displayed on the
7087: user's terminal during the translation of the document, instead of being
7088: produced in the translated document. This is useful for helping the user keep
7089: track of the progress of the translation and for prompting the user on the
7090: terminal for input required by the <tt>Read</tt> rule.</p>
1.18 cvs 7091: <pre> 'Write' Object [ Position ] ';'</pre>
1.30 cvs 7092:
7093: <p>Notice: if the translator is launched by the editor (by the ``Save as''
1.18 cvs 7094: command), messages produced by the <tt>Write</tt> rule are not displayed.</p>
1.30 cvs 7095:
1.18 cvs 7096: <blockquote class="example">
1.30 cvs 7097: <p><strong>Example:</strong></p>
7098:
7099: <p>To make the translator display the number of each section being
7100: translated on the user's terminal, the following rule is specified for the
7101: <tt>Section</tt> element type:</p>
7102: <pre>Section : BEGIN
1.1 cvs 7103: Write VarSection;
7104: ...
1.18 cvs 7105: END;</pre>
1.30 cvs 7106:
7107: <p>(see <a href="#varsectexample">above</a> for the definition of the
7108: <tt>VarSection</tt> variable).</p>
7109:
7110: <p>To display text on the terminal before issuing a read operation with the
7111: <tt>Read</tt> rule, the following rule is used:</p>
7112: <pre>BEGIN
1.1 cvs 7113: Write 'Enter the name of the destination: ';
7114: ...
1.18 cvs 7115: END;</pre>
7116: </blockquote>
7117: </div>
7118:
7119: <div class="subsection">
1.30 cvs 7120: <h3><a name="sectc5212">The <tt>Read</tt> rule</a></h3>
1.18 cvs 7121:
1.30 cvs 7122: <p>The <tt>Read</tt> rule reads text from the terminal during the translation
7123: of the document and saves the text read in one of the buffers declared in the
1.18 cvs 7124: <tt>BUFFERS</tt> section of the schema. The buffer to be used is indicated by
7125: its name, after the <tt>READ</tt> keyword. This name can be followed, as in
7126: the <tt>Create</tt> and <tt>Write</tt> rules, by a keyword indicating if the
7127: read operation must be performed <tt>Before</tt> or <tt>After</tt> the
1.1 cvs 7128: translation of the element's content. If this keyword is absent, the read
7129: operation is done beforehand. The text is read into the buffer and remains
1.5 cvs 7130: there until a rule using the same buffer - possibly the same rule - is
1.18 cvs 7131: applied.</p>
7132: <pre> 'Read' BufferID [ Position ] ';'</pre>
1.30 cvs 7133:
1.18 cvs 7134: <blockquote class="example">
1.30 cvs 7135: <p><strong>Example:</strong></p>
7136:
7137: <p>The following set of rules tells the user that the translator is waiting
7138: for the entry of some text, reads this text into a buffer and copies the
7139: text into the translated document.</p>
7140: <pre>BEGIN
1.1 cvs 7141: Write 'Enter the name of the destination: ';
7142: Read DestName;
7143: Create DestName;
7144: ...
1.18 cvs 7145: END;</pre>
1.30 cvs 7146:
7147: <p>(see <a href="#destname">above</a> the definition of
7148: <tt>DestName</tt>).</p>
1.18 cvs 7149: </blockquote>
7150: </div>
7151:
7152: <div class="subsection">
1.30 cvs 7153: <h3><a name="sectc5213">The <tt>Include</tt> rule</a></h3>
1.18 cvs 7154:
1.30 cvs 7155: <p>The <tt>Include</tt> rule, like the <tt>Create</tt> rule, is used to
7156: produce text in the translated document. It inserts constant text which is
7157: not defined in the translation schema, but is instead taken from a file. The
1.18 cvs 7158: file's name is specified after the <tt>Include</tt> keyword, either directly
1.1 cvs 7159: as a character string between apostrophes or as the name of one of the buffers
1.18 cvs 7160: declared in the <tt>BUFFERS</tt> section of the schema. In the latter case,
1.1 cvs 7161: the buffer is assumed to contain the file's name. This can be used when the
7162: included file's name is known only at the moment of translation. This only
1.18 cvs 7163: requires that the <tt>Include</tt> rule is preceded by a <tt>Read</tt> rule
7164: which puts the name of the file desired by the user into the buffer.</p>
1.30 cvs 7165:
7166: <p>Like the other rules, it is possible to specify whether the inclusion will
1.1 cvs 7167: occur before or after the element's content, with the default being before.
7168: The file inclusion is only done at the moment of translation, not during the
7169: compilation of the translation schema. Thus, the file to be included need not
7170: exist during the compilation, but it must be accessible at the time of
7171: translation. Its contents can also be modified between two translations, thus
7172: producing different results, even if neither the document or the translation
1.18 cvs 7173: schema are modified.</p>
1.30 cvs 7174:
7175: <p>During translation, the file to be included is searched for along the
7176: schema directory path (indicated by the environment variable
7177: <tt>THOTSCH</tt>). The file name is normally only composed of a simple name,
7178: without specification of a complete file path. However, if the filename
7179: starts with a '/', it is considered as an absolute path.</p>
1.18 cvs 7180: <pre> 'Include' File [ Position ] ';'
1.6 cvs 7181: File = FileName / BufferID .
1.18 cvs 7182: FileName = STRING .</pre>
1.30 cvs 7183:
1.18 cvs 7184: <blockquote class="example">
1.30 cvs 7185: <p><strong>Example:</strong></p>
7186:
7187: <p>Suppose that it is desirable to print documents of the Article class with
7188: a formatter which requires a number of declarations and definitions at the
7189: beginning of the file. The <tt>Include</tt>rule can be used to achieve
7190: this. All the declarations and definitions a replaced in a file called
7191: <tt>DeclarArt</tt> and then the <tt>Article</tt> element type is given the
7192: following rule:</p>
7193: <pre>Article : BEGIN
1.1 cvs 7194: Include 'DeclarArt' Before;
7195: ...
1.18 cvs 7196: END;</pre>
7197: </blockquote>
7198: </div>
7199:
7200: <div class="subsection">
1.30 cvs 7201: <h3><a name="sectc5214">The <tt>Get</tt> rule</a></h3>
1.18 cvs 7202:
1.30 cvs 7203: <p>The <tt>Get</tt> rule is used to change the order in which the elements
7204: appear in the translated document. More precisely, it produces the
7205: translation of a specified element before or after the translation of the
7206: content of the element to which the rule applies. The <tt>Before</tt> and
7207: <tt>After</tt> keywords are placed at the end of the rule to specify whether
7208: the operation should be performed before or after translation of the rule's
7209: element (the default is before). The type of the element to be moved must be
7210: specified after the <tt>Get</tt> keyword, optionally preceded by a keyword
7211: indicating where the element will be found in the logical structure of the
7212: document:</p>
1.18 cvs 7213: <dl>
1.30 cvs 7214: <dt><tt>Included</tt></dt>
7215: <dd>The element to be moved is the first element of the indicated type
7216: which is found inside the element to which the rule applies.</dd>
7217: <dt><tt>Referred</tt></dt>
7218: <dd>This keyword can only be used if the rule applies to a reference
7219: element. The element to be moved is either the element designated by the
7220: reference (if that element is of the specified type), or the first
7221: element of the desired type contained within the element designated by
7222: the reference.</dd>
7223: <dt>no keyword</dt>
7224: <dd>If the element to be moved is an associated element, defined in the <a
7225: href="#sectc314"><tt>ASSOC</tt> section</a> of the structure schema, all
7226: associated elements of this type which have not been translated yet are
7227: then translated. Certain elements may in fact have already been
7228: translated by a <tt>Get Referred</tt> rule.
7229: <p>If the element to be moved is not an associated element, the
7230: translator takes the first element of the indicated type from among the
7231: siblings of the rule's element. This is primarily used to change the
7232: order of the components of an aggregate.</p>
7233: </dd>
1.18 cvs 7234: </dl>
1.30 cvs 7235:
7236: <p>If the element to be moved is defined in a structure schema which is not
7237: the one which corresponds to the translation schema (in the case of an
7238: included object with a different schema), the type name of this element must
7239: be followed, between parentheses, by the name of the structure schema which
1.18 cvs 7240: defines it.</p>
7241: <pre> 'Get' [ RelPosition ] ElemID
1.6 cvs 7242: [ ExtStruct ]
7243: [ Position ] ';' /
7244: RelPosition = 'Included' / 'Referred' .
1.18 cvs 7245: ExtStruct = '(' ElemID ')' .</pre>
1.30 cvs 7246:
7247: <p>The <tt>Get</tt> rule has no effect if the element which it is supposed to
1.1 cvs 7248: move has already been translated. Thus, the element will not be duplicated.
7249: It is generally best to associate the rule with the first element which will
7250: be encountered by the translator in its traversal of the document. Suppose an
1.18 cvs 7251: aggregate has two elements <tt>A</tt> and <tt>B</tt>, with <tt>A</tt>
1.1 cvs 7252: appearing first in the logical structure. To permute these two elements, a
1.18 cvs 7253: <tt>Get B before</tt> rule should be associated with the <tt>A</tt> element
7254: type, not the inverse. Similarly, a rule of the form <tt>Get Included X
7255: After</tt>, even though syntactically correct, makes no sense since, by the
1.1 cvs 7256: time it will be applied, after the translation of the contents of the element
1.18 cvs 7257: to which it is attached, the <tt>X</tt> element will already have been
7258: translated.</p>
1.30 cvs 7259:
7260: <p>The <tt>Get</tt> rule is the only way to obtain the translation of the
1.1 cvs 7261: associated elements. In fact, the translator only traverses the primary tree
7262: of the document and thus does not translate the associated elements, except
1.18 cvs 7263: when the translation is explicitly required by a <tt>Get Referred Type</tt> or
7264: <tt>Get Type</tt> rule where <tt>Type</tt> is an associated element type.</p>
1.30 cvs 7265:
1.18 cvs 7266: <blockquote class="example">
1.30 cvs 7267: <p><strong>Example:</strong></p>
7268:
7269: <p>The structure schema defined figures as associated element which are
7270: composed of some content and a caption. Moreover, it is possible to make
7271: references to figures, using elements of the <tt>RefFigure</tt> type:</p>
7272: <pre> ...
1.1 cvs 7273: RefFigure = REFERENCE(Figure);
7274: ASSOC
1.6 cvs 7275: Figure = BEGIN
7276: Content = NATURE;
7277: Caption = Text;
7278: END;
1.18 cvs 7279: ...</pre>
1.30 cvs 7280:
7281: <p>Suppose it would be useful to make a figure appear in the translated
7282: document at the place in the text where the first reference to the figure is
7283: made. If some figures are not referenced, then they would appear at the end
7284: of the document. Also, each figure's caption should appear before the
7285: content. The following rules in the translation schema will produce this
7286: result:</p>
7287: <pre>Article : BEGIN
1.1 cvs 7288: ...
7289: Get Figures After;
7290: END;
7291: RefFigure : BEGIN
7292: If FirstRef Get Referred Figure;
7293: ...
7294: END;
7295: Content : BEGIN
7296: Get Caption Before;
7297: ...
1.18 cvs 7298: END;</pre>
7299: </blockquote>
7300: </div>
7301:
7302: <div class="subsection">
1.30 cvs 7303: <h3><a name="sectc5215">The <tt>Copy</tt> rule</a></h3>
1.18 cvs 7304:
1.30 cvs 7305: <p>Like the <tt>Get</tt> rule, the <tt>Copy</tt> rule generates the
7306: translation of a specified element, but it acts even if the element has
7307: already been translated and it allows to copy it or to translate it later.
7308: Both rules have the same syntax.</p>
1.18 cvs 7309: <pre> 'Copy' [ RelPosition ] ElemID
7310: [ ExtStruct ] [ Position ] ';'</pre>
7311: </div>
7312:
7313: <div class="subsection">
1.30 cvs 7314: <h3><a name="sectc5216">The <tt>Use</tt> rule</a></h3>
1.18 cvs 7315:
1.30 cvs 7316: <p>The <tt>Use</tt> rule specifies the translation schema to be applied to
1.1 cvs 7317: objects of a certain class that are part of the document. This rule only
7318: appears in the rules for the root element of the document (the first type
1.18 cvs 7319: defined after the <tt>STRUCT</tt> keyword in the structure schema) or the
1.1 cvs 7320: rules of an element defined by an external structure (by another structure
1.18 cvs 7321: schema). Also, the <tt>Use</tt> rule cannot be conditional.</p>
1.30 cvs 7322:
7323: <p>If the rule is applied to an element defined by an external structure, the
1.18 cvs 7324: <tt>Use</tt> keyword is simply followed by the name of the translation schema
1.1 cvs 7325: to be used for element constructed according to that external structure. If
7326: the rule is applied to the document's root element, it is formed by the
1.18 cvs 7327: <tt>Use</tt> keyword followed by the translation schema's name, the
7328: <tt>For</tt> keyword and the name of the external structure to which the
7329: indicated translation schema should be applied.</p>
7330: <pre> 'Use' TrSchema [ 'For' ElemID ] ';'
7331: TrSchema = NAME .</pre>
1.30 cvs 7332:
7333: <p>If no <tt>Use</tt> rule defines the translation schema to be used for an
1.1 cvs 7334: external structure which appears in a document, the translator asks the user,
7335: during the translation process, which schema should be used. Thus, it is not
1.18 cvs 7336: necessary to give the translation schema a <tt>Use</tt> rule for every
1.1 cvs 7337: external structure used, especially when the choice of translation schemas is
1.18 cvs 7338: to be left to the user.</p>
1.30 cvs 7339:
7340: <p>Notice: if the translator is launched by the editor (by the ``Save as''
1.18 cvs 7341: command), prompts are not displayed.</p>
1.30 cvs 7342:
1.18 cvs 7343: <blockquote class="example">
1.30 cvs 7344: <p><strong>Example:</strong></p>
7345:
7346: <p>The <tt>Article</tt> structure schema uses the <tt>Formula</tt> external
7347: structure, defined by another structure schema, for mathematical
7348: formulas:</p>
7349: <pre>STRUCTURE Article;
1.1 cvs 7350: ...
7351: STRUCT
7352: Article = ...
7353: ...
7354: Formula_in_text = Formula;
7355: Isolated_formula = Formula;
7356: ...
1.18 cvs 7357: END</pre>
1.30 cvs 7358:
7359: <p>Suppose that it would be useful to use the <tt>FormulaT</tt> translation
7360: schema for the formulas of an article. This can be expressed in two
7361: different ways in the <tt>Article</tt> class translation schema, using the
7362: rules:</p>
7363: <pre>RULES
1.1 cvs 7364: Article :
1.18 cvs 7365: Use FormulaT for Formula;</pre>
1.30 cvs 7366:
7367: <p>or:</p>
7368: <pre>RULES
1.1 cvs 7369: ...
7370: Formula :
1.18 cvs 7371: Use FormulaT;</pre>
7372: </blockquote>
7373: </div>
7374:
7375: <div class="subsection">
1.30 cvs 7376: <h3><a name="sectc5217">The <tt>Remove</tt> rule</a></h3>
1.18 cvs 7377:
1.30 cvs 7378: <p>The <tt>Remove</tt> rule indicates that nothing should be generated, in the
1.1 cvs 7379: translated document, for the content of the element to which the rule applies.
7380: The content of that element is simply ignored by the translator. This does
7381: not prevent the generation of text for the element itself, using the
1.18 cvs 7382: <tt>Create</tt> or <tt>Include</tt> rules, for example.</p>
1.30 cvs 7383:
7384: <p>The <tt>Remove</tt> rule is simply written with the <tt>Remove</tt>
7385: keyword. It is terminated, like all rules, by a semicolon.</p>
1.18 cvs 7386: <pre> 'Remove' ';'</pre>
7387: </div>
7388:
7389: <div class="subsection">
1.31 cvs 7390: <h3><a name="sectc5217a">The <tt>Ignore</tt> rule</a></h3>
7391:
7392: <p>The <tt>Ignore</tt> rule indicates that nothing should be generated, in the
7393: translated document, for the element to which the rule applies. The whole
1.32 ! cvs 7394: element is simply ignored by the translator.</p>
1.31 cvs 7395:
7396: <p>The <tt>Ignore</tt> rule is simply written with the <tt>Ignore</tt>
7397: keyword. It is terminated, like all rules, by a semicolon.</p>
7398: <pre> 'Ignore' ';'</pre>
7399: </div>
7400:
7401: <div class="subsection">
1.30 cvs 7402: <h3><a name="sectc5218">The <tt>NoTranslation</tt> rule</a></h3>
1.18 cvs 7403:
1.30 cvs 7404: <p>The <tt>NoTranslation</tt> rule indicates to the translator that it must
7405: not translate the content of the leaves of the element to which it applies. In
1.18 cvs 7406: contrast to the <tt>Remove</tt> rule, it does not suppress the content of the
1.1 cvs 7407: element, but it inhibits the translation of character strings, symbols, and
7408: graphical elements contained in the element. These are retrieved so that
1.18 cvs 7409: after the translation of the document, the rules of the <a
7410: href="#sectc5225"><tt>TEXTTRANSLATE</tt>, <tt>SYMBTRANSLATE</tt> and
7411: <tt>GRAPHTRANSLATE</tt> sections</a> will not be applied to them.</p>
1.30 cvs 7412:
7413: <p>The <tt>NoTranslation</tt> rule is written with the <tt>NoTranslation</tt>
1.18 cvs 7414: keyword followed by a semicolon.</p>
7415: <pre> 'NoTranslation' ';'</pre>
7416: </div>
7417:
7418: <div class="subsection">
1.30 cvs 7419: <h3><a name="sectc5219">The <tt>NoLineBreak</tt> rule</a></h3>
1.18 cvs 7420:
1.30 cvs 7421: <p>The <tt>NoLineBreak</tt> rule indicates to the translator that it must not
1.1 cvs 7422: generate additional line breaks in the output produced for the element to
1.18 cvs 7423: which it applies. This is as if it was an <a href="#sectc522">instruction
7424: <tt>LINELENGTH 0;</tt></a> at the beginning of the translation schema, but
7425: only for the current element.</p>
1.30 cvs 7426:
7427: <p>The <tt>NoLineBreak</tt> rule is written with the <tt>NoLineBreak</tt>
7428: keyword followed by a semicolon.</p>
1.18 cvs 7429: <pre> 'NoLineBreak' ';'</pre>
7430: </div>
1.1 cvs 7431:
1.18 cvs 7432: <div class="subsection">
1.30 cvs 7433: <h3><a name="sectc5220">The <tt>ChangeMainFile</tt> rule</a></h3>
1.1 cvs 7434:
1.30 cvs 7435: <p>When the translation program starts, it opens a main output file, whose
7436: name is given as a parameter of the translator. All <a
1.18 cvs 7437: href="#sectc5210"><tt>Create</tt> rules</a> without explicit indication of the
7438: output file write sequentially in this file. When a <tt>ChangeMainFile</tt>
7439: rule is executed, the main output file is closed and it is replaced by a new
7440: one, whose name is specified in the <tt>ChangeMainFile</tt> rule. The
7441: <tt>Create</tt> rules without indication of the output file that are then
7442: executed write in this new file. Several <tt>ChangeMainFile</tt> rules can be
7443: executed during the same translation, for dividing the main output into
7444: several files.</p>
1.30 cvs 7445:
7446: <p>This rule is written with the <tt>ChangeMainFile</tt> keyword followed by
7447: the name of a variable that specifies the name of the new main file. The
7448: keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule
7449: to specify whether the operation should be performed before or after
7450: translation of the rule's element (the default is before). This rule, like all
7451: translation rules, is terminated by a semicolon.</p>
1.18 cvs 7452: <pre> 'ChangeMainFile' VarID [ Position ] ';'</pre>
1.30 cvs 7453:
1.18 cvs 7454: <blockquote class="example">
1.30 cvs 7455: <p><strong>Example:</strong></p>
7456:
7457: <p>To generate the translation of each section in a different file, the
7458: following rule can be associated with type <tt>Section</tt>. That rule uses
7459: the <a href="#varoutputfile"><tt>VarOutpuFile</tt> variable</a> defined
7460: above.</p>
7461: <pre> Section:
1.18 cvs 7462: ChangeMainFile VarOutpuFile Before;</pre>
1.30 cvs 7463:
7464: <p>If <tt>output.txt</tt> is the name of the output file specified when
7465: starting the translation program, translated sections are written in files
7466: <tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>
1.18 cvs 7467: </blockquote>
7468: </div>
1.1 cvs 7469:
1.18 cvs 7470: <div class="subsection">
1.30 cvs 7471: <h3><a name="sectc5220a">The <tt>RemoveFile</tt> rule</a></h3>
1.14 cvs 7472:
1.30 cvs 7473: <p>Files may be used for storing temporary data that are no longer needed when
1.18 cvs 7474: the translation of a document is complete. These files may be removed by the
7475: <tt>RemoveFile</tt> rule.</p>
1.30 cvs 7476:
7477: <p>This rule is written with the <tt>RemoveFile</tt> keyword followed by the
7478: name of a variable that specifies the name of the file to be removed. The
7479: keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule
7480: to specify whether the operation should be performed before or after
7481: translation of the rule's element (the default is before). This rule, like
7482: all translation rules, is terminated by a semicolon.</p>
1.18 cvs 7483: <pre> 'RemoveFile' VarID [ Position ] ';'</pre>
7484: </div>
7485:
7486: <div class="subsection">
1.30 cvs 7487: <h3><a name="sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a></h3>
1.18 cvs 7488:
1.30 cvs 7489: <p>The <tt>Set</tt> and <tt>Add</tt> rules are used for modifying the value of
1.18 cvs 7490: counters that have no <a href="#sectc524">counting function</a>. Only this
7491: type of counter can be used in the <tt>Set</tt> and <tt>Add</tt> rules.</p>
1.30 cvs 7492:
7493: <p>Both rules have the same syntax: after the keyword <tt>Set</tt> or
1.18 cvs 7494: <tt>Add</tt> appear the counter name and the value to assign to the counter
7495: (<tt>Set</tt> rule) or the value to be added to the counter (<tt>Add</tt>
7496: rule). The keyword <tt>Before</tt> or <tt>After</tt> can follow that value to
1.1 cvs 7497: indicate when the rule must be applied: before or after the element's content
1.18 cvs 7498: is translated. By default, <tt>Before</tt> is assumed. A semicolon terminates
7499: the rule.</p>
7500: <pre> 'Set' CounterID InitValue [ Position ] ';' /
7501: 'Add' CounterID Increment [ Position ] ';'</pre>
7502: </div>
7503:
7504: <div class="subsection">
1.30 cvs 7505: <h3><a name="sectc5221a">The <tt>Indent</tt> rule</a></h3>
1.18 cvs 7506:
1.30 cvs 7507: <p>The <tt>Indent</tt> rule is used to modify the value of text indentation in
1.18 cvs 7508: the output files.</p>
1.30 cvs 7509:
7510: <p>Each time the translator creates a new line in an output file, it generates
7511: a variable number of space characters at the beginning of the new line. By
1.25 cvs 7512: default, the number of these characters (the indentation value) is 0. It can
7513: be changed with the <tt>Indent</tt> rule.</p>
1.30 cvs 7514:
7515: <p>In its simple form, the rule begins with the <tt>Indent</tt> keyword,
1.25 cvs 7516: followed by the indentation sign (optional) and value and a keyword
1.30 cvs 7517: <tt>Before</tt> or <tt>After</tt> indicating that the indentation should be
7518: changed <a href="#sectc5222">before or after</a> the element's content is
7519: generated. If the position is not indicated, the indentation is changed
1.25 cvs 7520: before the element's content is generated. This rule, like all translation
7521: rules, is terminated by a semicolon.</p>
1.30 cvs 7522:
7523: <p>The indentation value is indicated by an integer, which is the number of
7524: space characters to be generated at the beginning of each new line. A sign
1.18 cvs 7525: (<tt>+</tt> or <tt>-</tt>) can appear before the integer to indicate that the
7526: value is relative: the current value of indentation is incremented (if sign is
7527: <tt>+</tt>) or decremented (if sign is <tt>-</tt>) by the specified value.</p>
1.30 cvs 7528:
7529: <p>Keyword <tt>Suspend</tt> or <tt>Resume</tt> can appear instead of the
1.25 cvs 7530: (possibly signed) identation value. <tt>Suspend</tt> means that the new
1.30 cvs 7531: indentation value to be used is zero until another <tt>Indent</tt> rule is
7532: executed and changes the indentation value. <tt>Resume</tt> means that the
7533: indentation value that was used before the last <tt>Indent Suspend</tt> was
7534: executed becomes the new value. Only one <tt>Suspend</tt> can be used before
7535: a <tt>Resume</tt>; <tt>Supend</tt>-<tt>Resume</tt> pairs can not be
7536: nested.</p>
7537:
7538: <p>Like the <a href="#sectc5210"><tt>Create</tt> rule</a>, the <tt>Indent</tt>
1.18 cvs 7539: keyword can be followed by the <tt>IN</tt> keyword and by the name of a <a
7540: href="#sectc526">variable</a>. This means that the rule must not change
1.10 cvs 7541: indentation in the main output file, but in the file whose name is specified
7542: by the variable (by default, indentation is changed in the main output
1.18 cvs 7543: file).</p>
1.25 cvs 7544: <pre> 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .
1.10 cvs 7545:
1.25 cvs 7546: Indent = 'Suspend' / 'Resume' / [ IndentSign ] IndentValue .
1.10 cvs 7547: IndentSign = '+' / '-' .
1.18 cvs 7548: IndentValue = NUMBER .</pre>
7549: </div>
1.10 cvs 7550:
1.18 cvs 7551: <div class="subsection">
1.30 cvs 7552: <h3><a name="sectc5222">Rule application order</a></h3>
1.1 cvs 7553:
1.30 cvs 7554: <p>The translator translates the elements which comprise the document in the
1.18 cvs 7555: order induced by the tree structure, except when the <tt>Get</tt> rule is used
1.1 cvs 7556: to change the order of translation. For each element, the translator first
7557: applies the rules specified for the element's type that must be applied before
1.18 cvs 7558: translation of the element's content (rules ending with the <tt>Before</tt>
1.1 cvs 7559: keyword or which have no position keyword). If several rules meet these
7560: criteria, the translator applies them in the order in where they appear in the
1.18 cvs 7561: translation schema.</p>
1.30 cvs 7562:
7563: <p>It then applies all <a href="#sectc5223">rules for the attributes</a> which
1.1 cvs 7564: the element has and which must be applied before the translation of the
1.18 cvs 7565: element's content (rules ending with the <tt>Before</tt> keyword or which have
1.1 cvs 7566: no position keyword). For one attribute value, the translator applies the
1.18 cvs 7567: rules in the order in which they are defined in the translation schema.</p>
1.30 cvs 7568:
7569: <p>The same procedure is followed with translation rules for specific
1.18 cvs 7570: presentations.</p>
1.30 cvs 7571:
1.31 cvs 7572: <p>Next, the element's content is translated, as long as a <tt>Remove</tt> or
7573: <code>Ignore</code> rule does not apply.</p>
1.30 cvs 7574:
7575: <p>In the next step, the translator applies rules for the specific
7576: presentation of the element that are to be applied after translation of the
7577: content (rules which end with the <tt>After</tt> keyword). The rules for each
7578: type of presentation rule or each value are applied in the order in which the
1.18 cvs 7579: translation appear in the schema.</p>
1.30 cvs 7580:
7581: <p>Then, the same procedure is followed for translation rules for attributes
7582: of the element.</p>
7583:
7584: <p>Finally, the translator applies rules for the element which must be applied
1.1 cvs 7585: after translation of the element's content. These rules are applied in the
7586: order that they appear in the translation schema. When the translation of an
7587: element is done, the translator procedes to translate the following
1.18 cvs 7588: element.</p>
1.30 cvs 7589:
7590: <p>This order can be changed with the <tt>Attributes</tt> and
1.18 cvs 7591: <tt>Presentation</tt> options of the <a href="#sectc5210"><tt>Create</tt>
7592: rule</a>.</p>
7593: </div>
1.1 cvs 7594:
1.18 cvs 7595: <div class="subsection">
1.30 cvs 7596: <h3><a name="sectc5223">Translation of logical attributes</a></h3>
1.1 cvs 7597:
1.30 cvs 7598: <p>After the rules for the element types, the translation schema defines rules
1.18 cvs 7599: for attribute values. This section begins with the <tt>ATTRIBUTES</tt>
1.1 cvs 7600: keyword and is composed of a sequence of rule blocks each preceded by an
1.18 cvs 7601: attribute name and an optional value or value range.</p>
1.30 cvs 7602:
7603: <p>If the attribute's name appears alone before the rule block, the rule are
1.1 cvs 7604: applied to all element which have the attribute, no matter what value the
7605: attribute has. In this case, the attribute name is followed by a colon before
1.18 cvs 7606: the beginning of the rule block.</p>
1.30 cvs 7607:
7608: <p>The attribute's name can be followed by the name of an element type between
1.1 cvs 7609: parentheses. This says, as in presentation schemas, that the rule block which
7610: follows applies not to the element which has the attribute, but to its
1.18 cvs 7611: descendants of the type indicated between the parentheses.</p>
1.30 cvs 7612:
7613: <p>If values are given after the attribute name (or after the name of the
7614: element type), the rules are applied only when the attribute has the indicated
7615: values. The same attribute can appear several times, with different values and
1.1 cvs 7616: different translation rules. Attribute values are indicated in the same way
1.18 cvs 7617: as in <a href="#sectc528">conditions</a> and are followed by a colon before
7618: the block of rules.</p>
1.30 cvs 7619:
7620: <p>The rule block associated with an attribute is either a simple rule or a
1.18 cvs 7621: sequence of rules delimited by the <tt>BEGIN</tt> and <tt>END</tt> keywords.
7622: Note that rules associated with attribute values cannot be conditional.</p>
1.30 cvs 7623:
7624: <p>Translation rules are not required for all attributes (or their values)
1.1 cvs 7625: defined in a structure schema. Only those attributes for which a particular
7626: action must be performed by the translator must have such rules. The rules
1.18 cvs 7627: that can be used are those described above, from <a
7628: href="#sectc5210"><tt>Create</tt></a> to <a
7629: href="#sectc5218"><tt>NoTranslation</tt></a>.</p>
1.30 cvs 7630: <pre> AttrSeq = TransAttr < TransAttr > .
1.1 cvs 7631: TransAttr = AttrID [ '(' ElemID ')' ]
7632: [ RelatAttr ] ':' RuleSeq .
7633: AttrID = NAME .
1.18 cvs 7634: ElemID = NAME .</pre>
1.30 cvs 7635:
1.18 cvs 7636: <blockquote class="example">
1.30 cvs 7637: <p><strong>Example:</strong></p>
7638:
7639: <p>The structure defined the ``Language'' attribute which can take the
7640: values ``French'' and ``English''. To have the French parts of the original
7641: document removed and prevent the translation of the leaves of the English
7642: parts, the following rules would be used:</p>
7643: <pre>ATTRIBUTES
1.1 cvs 7644: Language=French :
7645: Remove;
7646: Language=English :
1.18 cvs 7647: NoTranslation;</pre>
7648: </blockquote>
7649: </div>
1.1 cvs 7650:
1.18 cvs 7651: <div class="subsection">
1.30 cvs 7652: <h3><a name="sectc5224">Translation of specific presentations</a></h3>
1.1 cvs 7653:
1.30 cvs 7654: <p>After the rules for attributes, the translation schema defines rules for
7655: the specific presentation. This section begins with the <tt>PRESENTATION</tt>
1.1 cvs 7656: keyword and is composed of a sequence of translation rule blocks each preceded
7657: by a presentation rule name, optionally accompanied by a part which depends on
1.18 cvs 7658: the particular presentation rule.</p>
1.30 cvs 7659:
7660: <p>Each of these translation rule blocks is applied when the translator
7661: operates on an element which has a specific presentation rule of the type
7662: indicated at the head of the block. Depending on the type of the specific
7663: presentation rule, it is possible to specify values of the presentation rule
7664: for which the translation rule block should be applied.</p>
7665:
7666: <p>There are three categories of the presentation rules:</p>
7667: <ul>
7668: <li>rules taking numeric values: <tt>Size</tt>, <tt>Indent</tt>,
7669: <tt>LineSpacing</tt>, <tt>LineWeight</tt>,</li>
7670: <li>rules whose values are taken from a predefined list (i.e. whose type is
7671: an enumeration): <tt>Adjust</tt>, <tt>Justify</tt>, <tt>Hyphenate,/TT>,
7672: <tt>Style</tt>, <tt>Weight</tt>, <tt>Font</tt>, <tt>UnderLine</tt>,
7673: <tt>Thickness</tt>, <tt>LineStyle</tt>,</tt></li>
7674: <li>rules whose value is a name: <tt>FillPattern</tt>, <tt>Background</tt>,
7675: <tt>Foreground</tt>.</li>
1.18 cvs 7676: </ul>
1.30 cvs 7677:
7678: <p>For presentation rules of the first category, the values which provoke
1.1 cvs 7679: application of the translation rules are indicated in the same manner as for
1.18 cvs 7680: <a href="#relattr">numeric attributes</a>. This can be either a unique value
1.1 cvs 7681: or range of values. For a unique value, the value (an integer) is simply
7682: preceded by an equals sign. Value ranges can be specified in one of three
1.18 cvs 7683: ways:</p>
7684: <ul>
1.30 cvs 7685: <li>all values less than a given value (this value is preceded by a ``less
7686: than'' sign '<tt><</tt>'),</li>
7687: <li>all values greater than a given value (this value is preceded by a`
7688: `greater than'' sign '<tt>></tt>'),</li>
7689: <li>all values falling in an interval, bounds included. The range of values
7690: is then specified <tt>IN [</tt>Minimum<tt>..</tt>Maximum<tt>]</tt>, where
7691: Minimum and Maximum are integers.</li>
1.18 cvs 7692: </ul>
1.30 cvs 7693:
7694: <p>All numeric values can be negative, in which case the integer is preceded
7695: by a minus sign. All values must be given in typographers points.</p>
7696:
7697: <p>For presentation rules whose values are taken from a predefined list, the
1.1 cvs 7698: value which provokes application of the translation rules is simply indicated
1.18 cvs 7699: by the equals sign followed by the name of the value.</p>
1.30 cvs 7700:
7701: <p>For presentation rules whose values are names, the value which provokes the
1.1 cvs 7702: application of translation rules is simply indicated by the equals sign
7703: followed by the name of the value. The names of the fill patterns (the
1.18 cvs 7704: <tt>FillPattern</tt> rule) and of the colors (the <tt>Foreground</tt> and
7705: <tt>Background</tt> rules) used in Thot are the same as in the P language.</p>
1.30 cvs 7706: <pre> PresSeq = PresTrans < PresTrans > .
1.1 cvs 7707: PresTrans = PresRule ':' RuleSeq .
7708: PresRule = 'Size' [ PresRelation ] /
7709: 'Indent' [ PresRelation ] /
7710: 'LineSpacing' [ PresRelation ] /
7711: 'Adjust' [ '=' AdjustVal ] /
7712: 'Justify' [ '=' BoolVal ] /
7713: 'Hyphenate' [ '=' BoolVal ] /
7714: 'Style' [ '=' StyleVal ] /
1.24 cvs 7715: 'Weight' [ '=' WeightVal ] /
1.1 cvs 7716: 'Font' [ '=' FontVal ] /
7717: 'UnderLine' [ '=' UnderLineVal ] /
7718: 'Thickness' [ '=' ThicknessVal ] /
7719: 'LineStyle' [ '=' LineStyleVal ] /
7720: 'LineWeight' [ PresRelation ] /
7721: 'FillPattern' [ '=' Pattern ] /
7722: 'Background' [ '=' Color ] /
7723: 'Foreground' [ '=' Color ] .
7724:
7725: PresRelation = '=' PresValue /
1.30 cvs 7726: '>' [ '-' ] PresMinimum /
1.1 cvs 7727: '<' [ '-' ] PresMaximum /
7728: 'IN' '[' [ '-' ] PresIntervalMin '..'
7729: [ '-' ] PresIntervalMax ']' .
7730: AdjustVal = 'Left' / 'Right' / 'VMiddle' /
7731: 'LeftWithDots' .
7732: BoolVal = 'Yes' / 'No' .
1.24 cvs 7733: StyleVal = 'Roman' / 'Italics' / 'Oblique' .
7734: WeightVal = 'Normal' / 'Bold' .
1.1 cvs 7735: FontVal = 'Times' / 'Helvetica' / 'Courier' .
7736: UnderLineVal = 'NoUnderline' / 'UnderLined' /
7737: 'OverLined' / 'CrossedOut' .
7738: ThicknessVal = 'Thick' / 'Thin' .
1.6 cvs 7739: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
1.1 cvs 7740: Pattern = NAME .
7741: Color = NAME .
7742: PresMinimum = NUMBER .
7743: PresMaximum = NUMBER .
7744: PresIntervalMin= NUMBER .
7745: PresIntervalMax= NUMBER .
7746: PresValue = [ '-' ] PresVal .
1.18 cvs 7747: PresVal = NUMBER .</pre>
1.30 cvs 7748:
7749: <p>The <a name="prestransl">translation rules associated with specific
1.18 cvs 7750: presentation rules</a> can use the value of the specific presentation rule
1.1 cvs 7751: that causes them to be applied. This behavior is designated by the keyword
1.18 cvs 7752: <tt>Value</tt>. For numerically-valued presentation rules, the numeric value
1.1 cvs 7753: is produced. For other presentation rules, the name of the value is
1.18 cvs 7754: produced.</p>
1.30 cvs 7755:
7756: <p>It should be noted that modifications to the layout of the document's
7757: elements that are made using the combination of the control key and a mouse
7758: button will have no effect on the translation of the document.</p>
7759:
7760: <blockquote class="example">
7761: <p><strong>Example:</strong></p>
7762:
7763: <p>Suppose that it is desirable to use the same font sizes as in the
7764: specific presentation, but the font size must be between 10 and 18
7765: typographer's points. If font size is set in the translated document by the
7766: string <tt>pointsize=n</tt> where <tt>n</tt> is the font size in
7767: typographer's points then the following rules will suffice:</p>
7768: <pre>PRESENTATION
1.1 cvs 7769: Size < 10 :
7770: Create 'pointsize=10';
7771: Size in [10..18] :
7772: BEGIN
7773: Create 'pointsize=';
7774: Create Value;
7775: END;
1.30 cvs 7776: Size > 18 :
1.18 cvs 7777: Create 'pointsize=18';</pre>
7778: </blockquote>
7779: </div>
1.1 cvs 7780:
1.18 cvs 7781: <div class="subsection">
1.30 cvs 7782: <h3><a name="sectc5225">Recoding of characters, symbols and graphics</a></h3>
1.1 cvs 7783:
1.30 cvs 7784: <p>The coding of characters, graphical elements and symbols as defined in Thot
1.1 cvs 7785: does not necessarily correspond to what is required by an application to which
7786: a Thot document must be exported. Because of this the translator can recode
7787: these terminal elements of the documents structure. The last sections of a
7788: translation schema are intended for this purpose, each specifying the recoding
1.18 cvs 7789: rules for one type of terminal element.</p>
1.30 cvs 7790:
7791: <p>The recoding rules for character strings are grouped by alphabets. There is
7792: a group of rules for each alphabet of the Thot document that must be
7793: translated. Each such group of rules begins with the <tt>TEXTTRANSLATE</tt>
7794: keyword, followed by the specification of the alphabet to translate and the
7795: recoding rules, between the <tt>BEGIN</tt> and <tt>END</tt> keywords unless
7796: there is only one recoding rule for the alphabet. The specification of the
7797: alphabet is not required: by default it is assumed to the Latin alphabet (the
7798: ISO Latin-1 character set).</p>
7799:
7800: <p>Each recoding rule is formed by a source string between apostrophes and a
1.1 cvs 7801: target string, also between apostrophes, the two strings being separated by
1.30 cvs 7802: the arrow symbol (<tt>-></tt>), formed by the ``minus'' and ``greater
7803: than'' characters. The rule is terminated by a semi-colon.</p>
1.18 cvs 7804: <pre> TextTransSeq = [ Alphabet ] TransSeq .
1.1 cvs 7805: Alphabet = NAME .
1.30 cvs 7806: TransSeq ='BEGIN' < Translation > 'END' ';' /
1.1 cvs 7807: Translation .
1.30 cvs 7808: Translation = Source [ '->' Target ] ';' .
1.1 cvs 7809: Source = STRING .
1.18 cvs 7810: Target = STRING .</pre>
1.30 cvs 7811:
7812: <p>One such rule signifies that when the source string appears in a text leaf
7813: of the document being translated, the translator must replace it, in the
1.1 cvs 7814: translated document, with the target string. The source string and the target
7815: string can have different lengths and the target string can be empty. In this
7816: last case, the translator simply suppresses every occurrence of the source
1.18 cvs 7817: string in the translated document.</p>
1.30 cvs 7818:
7819: <p>For a given alphabet, the order of the rules is not important and has no
1.1 cvs 7820: significance because the T language compiler reorders the rules in ways that
7821: speed up the translator's work. The total number of recoding rules is limited
1.18 cvs 7822: by the compiler as is the maximum length of the source and target strings.</p>
1.30 cvs 7823:
7824: <p>The recoding rules for symbols and graphical elements are written in the
7825: same manner as the recoding rules for character strings. They are preceded,
1.18 cvs 7826: respectively, by the <tt>SYMBTRANSLATE</tt> and <tt>GRAPHTRANSLATE</tt> and so
1.1 cvs 7827: not require a specification of the alphabet. Their source string is limited to
7828: one character, since, in Thot, each symbol and each graphical element is
7829: represented by a single character. The symbol and graphical element codes are
1.18 cvs 7830: defined along with the <a href="#sect7">non-standard character codes</a>.</p>
1.30 cvs 7831:
1.18 cvs 7832: <blockquote class="example">
1.30 cvs 7833: <p><strong>Example:</strong></p>
7834:
7835: <p>In a translation schema producing documents destined for use with the
7836: L<sup>A</sup>T<sub><big>E</big></sub>X formatter, the Latin characters``é''
7837: (octal code 351 in Thot) and ``č'' (octal code 350 in Thot) must be
7838: converted to their representation in
7839: L<sup>A</sup>T<sub><big>E</big></sub>X:</p>
7840: <pre>TEXTTRANSLATE Latin
1.1 cvs 7841: BEGIN
1.30 cvs 7842: '\350' -> '\`{e}'; { e grave }
7843: '\351' -> '\''{e}'; { e acute }
1.18 cvs 7844: END;</pre>
7845: </blockquote>
7846: </div>
7847: </div>
7848: <hr>
7849: </div>
1.1 cvs 7850:
1.18 cvs 7851: <div class="chapter">
1.30 cvs 7852: <h1><a name="sect6">Language grammars</a></h1>
1.1 cvs 7853:
1.30 cvs 7854: <p>This chapter gives the complete grammars of the languages of Thot. The
1.1 cvs 7855: grammars were presented and described in the preceding chapters, which also
7856: specify the semantics of the languages. This section gives only the
1.18 cvs 7857: syntax.</p>
1.1 cvs 7858:
1.18 cvs 7859: <div class="section">
1.30 cvs 7860: <h2><a name="sectb61">The M meta-language</a></h2>
1.1 cvs 7861:
1.30 cvs 7862: <p>The language grammars are all expressed in the same formalism, the M
1.18 cvs 7863: meta-language, which is defined in this section.</p>
7864: <pre>{ Any text between braces is a comment. }
1.30 cvs 7865: Grammar = Rule < Rule > 'END' .
7866: { The < and > signs indicate zero }
1.1 cvs 7867: { or more repetitions. }
7868: { END marks the end of the grammar. }
7869: Rule = Ident '=' RightPart '.' .
7870: { The period indicates the end of a rule }
7871: RightPart = RtTerminal / RtIntermed .
7872: { The slash indicates a choice }
7873: RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
7874: { Right part of a terminal rule }
1.30 cvs 7875: RtIntermed = Possibility < '/' Possibility > .
1.1 cvs 7876: { Right part of an intermediate rule }
1.30 cvs 7877: Possibility = ElemOpt < ElemOpt > .
7878: ElemOpt = Element / '[' Element < Element > ']' /
7879: '<' Element < Element > '>' .
1.1 cvs 7880: { Brackets delimit optional parts }
7881: Element = Ident / KeyWord .
7882: Ident = NAME .
7883: { Identifier, sequence of characters
7884: KeyWord = STRING .
7885: { Character string delimited by apostrophes }
1.18 cvs 7886: END</pre>
7887: </div>
1.1 cvs 7888:
1.18 cvs 7889: <div class="section">
1.30 cvs 7890: <h2><a name="sectb62">The S language</a></h2>
1.1 cvs 7891:
1.30 cvs 7892: <p>The S language is used to write structure schemas, which contain the
7893: generic logical structures of document and object classes. It is described
7894: here in the M meta-language.</p>
1.18 cvs 7895: <pre>StructSchema = 'STRUCTURE' [ 'EXTENSION' ] ElemID ';'
1.1 cvs 7896: 'DEFPRES' PresID ';'
7897: [ 'ATTR' AttrSeq ]
7898: [ 'PARAM' RulesSeq ]
7899: [ 'STRUCT' RulesSeq ]
7900: [ 'EXTENS' ExtensRuleSeq ]
7901: [ 'ASSOC' RulesSeq ]
7902: [ 'UNITS' RulesSeq ]
7903: [ 'EXPORT' SkeletonSeq ]
7904: [ 'EXCEPT' ExceptSeq ]
7905: 'END' .
7906:
7907: ElemID = NAME .
7908: PresID = NAME .
7909:
1.30 cvs 7910: AttrSeq = Attribute < Attribute > .
1.1 cvs 7911: Attribute = AttrID '=' AttrType ';' .
7912: AttrType = 'INTEGER' / 'TEXT' /
7913: 'REFERENCE' '(' RefType ')' /
7914: ValueSeq .
7915: RefType = 'ANY' /
7916: [ FirstSec ] ElemID [ ExtStruct ] .
1.30 cvs 7917: ValueSeq = AttrVal < ',' AttrVal > .
1.1 cvs 7918: AttrID = NAME .
7919: FirstSec = 'First' / 'Second' .
7920: ExtStruct = '(' ElemID ')' .
7921: AttrVal = NAME .
7922:
1.30 cvs 7923: RulesSeq = Rule < Rule > .
1.1 cvs 7924: Rule = ElemID [ LocAttrSeq ] '='
7925: DefWithAttr ';' .
7926: LocAttrSeq = '(' 'ATTR' LocalAttr
1.30 cvs 7927: < ';' LocalAttr > ')' .
1.1 cvs 7928: LocalAttr = [ '!' ] AttrID [ '=' AttrType ] .
7929: DefWithAttr = Definition
7930: [ '+' '(' ExtensionSeq ')' ]
7931: [ '-' '(' RestrictSeq ')' ]
7932: [ 'WITH' FixedAttrSeq ] .
1.30 cvs 7933: ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
1.1 cvs 7934: ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
7935: 'SYMBOL' / 'PICTURE' .
1.30 cvs 7936: RestrictSeq = RestrictElem < ',' RestrictElem > .
1.1 cvs 7937: RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
7938: 'SYMBOL' / 'PICTURE' .
1.30 cvs 7939: FixedAttrSeq = FixedAttr < ',' FixedAttr > .
1.1 cvs 7940: FixedAttr = AttrID [ FixedOrModifVal ] .
7941: FixedOrModifVal= [ '?' ] '=' FixedValue .
7942: FixedValue = [ '-' ] NumValue / TextValue / AttrVal .
7943: NumValue = NUMBER .
7944: TextValue = STRING .
7945:
7946: Definition = BaseType [ LocAttrSeq ] / Constr /
7947: Element .
7948: BaseType = 'TEXT' / 'GRAPHICS' / 'SYMBOL' /
7949: 'PICTURE' / 'UNIT' / 'NATURE' .
7950: Element = ElemID [ ExtOrDef ] .
7951: ExtOrDef = 'EXTERN' / 'INCLUDED' /
7952: [ LocAttrSeq ] '=' Definition .
7953:
7954: Constr = 'LIST' [ '[' min '..' max ']' ] 'OF'
7955: '(' DefWithAttr ')' /
7956: 'BEGIN' DefOptSeq 'END' /
7957: 'AGGREGATE' DefOptSeq 'END' /
7958: 'CASE' 'OF' DefSeq 'END' /
7959: 'REFERENCE' '(' RefType ')' /
7960: 'PAIR' .
7961:
7962: min = Integer / '*' .
7963: max = Integer / '*' .
7964: Integer = NUMBER .
7965:
1.30 cvs 7966: DefOptSeq = DefOpt ';' < DefOpt ';' > .
1.1 cvs 7967: DefOpt = [ '?' ] DefWithAttr .
7968:
1.30 cvs 7969: DefSeq = DefWithAttr ';' < DefWithAttr ';' > .
1.1 cvs 7970:
1.30 cvs 7971: SkeletonSeq = SkeletonElem < ',' SkeletonElem > ';' .
1.1 cvs 7972: SkeletonElem = ElemID [ 'WITH' Contents ] .
7973: Contents = 'Nothing' / ElemID [ ExtStruct ] .
7974:
1.30 cvs 7975: ExceptSeq = Except ';' < Except ';' > .
1.1 cvs 7976: Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr ':'
7977: ExcValSeq .
7978: ExcTypeOrAttr = ElemID / AttrID .
1.30 cvs 7979: ExcValSeq = ExcValue < ',' ExcValue > .
1.1 cvs 7980: ExcValue = 'NoCut' / 'NoCreate' /
7981: 'NoHMove' / 'NoVMove' / 'NoMove' /
7982: 'NoHResize' / 'NoVResize' / 'NoResize' /
1.18 cvs 7983: 'MoveResize' /
1.1 cvs 7984: 'NewWidth' / 'NewHeight' /
7985: 'NewHPos' / 'NewVPos' /
7986: 'Invisible' / 'NoSelect' /
7987: 'Hidden' / 'ActiveRef' /
7988: 'ImportLine' / 'ImportParagraph' /
1.9 cvs 7989: 'NoPaginate' / 'ParagraphBreak' /
7990: 'HighlightChildren' / 'ExtendedSelection' /
1.29 cvs 7991: 'ReturnCreateNL' / 'ReturnCreateWithin' .
1.1 cvs 7992:
1.30 cvs 7993: ExtensRuleSeq = ExtensRule ';' < ExtensRule ';' > .
1.1 cvs 7994: ExtensRule = RootOrElem [ LocAttrSeq ]
7995: [ '+' '(' ExtensionSeq ')' ]
7996: [ '-' '(' RestrictSeq ')' ]
7997: [ 'WITH' FixedAttrSeq ] .
7998: RootOrElem = 'Root' / ElemID .
7999:
1.18 cvs 8000: END</pre>
8001: </div>
1.1 cvs 8002:
1.18 cvs 8003: <div class="section">
1.30 cvs 8004: <h2><a name="sectb63">The P language</a></h2>
1.1 cvs 8005:
1.30 cvs 8006: <p>The P language is used to write presentation schemas, which define the
1.1 cvs 8007: graphical presentation rules to be applied to different classes of documents
1.18 cvs 8008: and objects. It is described here in the M meta-language.</p>
8009: <pre>PresSchema = 'PRESENTATION' ElemID ';'
1.1 cvs 8010: [ 'VIEWS' ViewSeq ]
8011: [ 'PRINT' PrintViewSeq ]
8012: [ 'COUNTERS' CounterSeq ]
8013: [ 'CONST' ConstSeq ]
8014: [ 'VAR' VarSeq ]
8015: [ 'DEFAULT' ViewRuleSeq ]
8016: [ 'BOXES' BoxSeq ]
8017: [ 'RULES' PresentSeq ]
8018: [ 'ATTRIBUTES' PresAttrSeq ]
8019: [ 'TRANSMIT' TransmitSeq ]
8020: 'END' .
8021:
8022: ElemID = NAME .
8023:
8024: ViewSeq = ViewDeclaration
1.30 cvs 8025: < ',' ViewDeclaration > ';' .
1.1 cvs 8026: ViewDeclaration = ViewID [ 'EXPORT' ] .
8027: ViewID = NAME .
8028:
1.30 cvs 8029: PrintViewSeq = PrintView < ',' PrintView > ';' .
1.1 cvs 8030: PrintView = ViewID / ElemID .
8031:
1.30 cvs 8032: CounterSeq = Counter < Counter > .
1.1 cvs 8033: Counter = CounterID ':' CounterFunc ';' .
8034: CounterID = NAME .
8035: CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
8036: [ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
1.30 cvs 8037: SetFunction < SetFunction >
8038: AddFunction < AddFunction >
1.1 cvs 8039: [ 'INIT' AttrID ] /
1.16 cvs 8040: 'RLEVEL' 'OF' ElemID .
1.1 cvs 8041: SLevelAsc = [ '-' ] LevelAsc .
8042: LevelAsc = NUMBER .
8043: SetFunction = 'SET' CounterValue 'ON' TypeOrPage .
8044: AddFunction = 'ADD' CounterValue 'ON' TypeOrPage .
8045: TypeOrPage = 'Page' [ '(' ViewID ')' ] /
1.16 cvs 8046: [ '*' ] ElemID .
1.1 cvs 8047: CounterValue = NUMBER .
8048:
1.30 cvs 8049: ConstSeq = Const < Const > .
1.1 cvs 8050: Const = ConstID '=' ConstType ConstValue ';' .
8051: ConstID = NAME .
8052: ConstType = 'Text' [ Alphabet ] / 'Symbol' /
8053: 'Graphics' / 'Picture' .
8054: ConstValue = STRING .
8055: Alphabet = NAME .
8056:
1.30 cvs 8057: VarSeq = Variable < Variable > .
1.1 cvs 8058: Variable = VarID ':' FunctionSeq ';' .
8059: VarID = NAME .
1.30 cvs 8060: FunctionSeq = Function < Function > .
1.1 cvs 8061: Function = 'DATE' / 'FDATE' /
8062: 'DocName' / 'DirName' /
8063: 'ElemName' / 'AttributeName' /
8064: ConstID / ConstType ConstValue /
8065: AttrID /
8066: 'VALUE' '(' PageAttrCtr ','
8067: CounterStyle ')' .
8068: PageAttrCtr = 'PageNumber' [ '(' ViewID ')' ] /
8069: [ MinMax ] CounterID / AttrID .
8070: CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
8071: 'Uppercase' / 'Lowercase' .
8072: MinMax = 'MaxRangeVal' / 'MinRangeVal' .
8073:
1.30 cvs 8074: BoxSeq = Box < Box > .
1.1 cvs 8075: Box = 'FORWARD' BoxID ';' /
8076: BoxID ':' ViewRuleSeq .
8077: BoxID = NAME .
8078:
1.30 cvs 8079: PresentSeq = Present < Present > .
1.1 cvs 8080: Present = [ '*' ] [ FirstSec ] ElemID ':'
8081: ViewRuleSeq .
8082: FirstSec = 'First' / 'Second' .
8083:
1.30 cvs 8084: PresAttrSeq = PresAttr < PresAttr > .
1.1 cvs 8085: PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
8086: [ AttrRelation ] ':' ViewRuleSeq .
8087: AttrID = NAME .
8088: AttrRelation = '=' AttrVal /
1.30 cvs 8089: '>' [ '-' ] MinValue /
1.1 cvs 8090: '<' [ '-' ] MaxValue /
8091: 'IN' '[' [ '-' ] LowerBound '..'
8092: [ '-' ] UpperBound ']' /
8093: 'GREATER' AttrID /
8094: 'EQUAL' AttrID /
8095: 'LESS' AttrID .
8096: AttrVal = [ '-' ] EqualNum / EqualText / AttrValue .
8097: MinValue = NUMBER .
8098: MaxValue = NUMBER .
8099: LowerBound = NUMBER .
8100: UpperBound = NUMBER.
8101: EqualNum = NUMBER .
8102: EqualText = STRING .
8103: AttrValue = NAME .
8104:
1.30 cvs 8105: ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
1.1 cvs 8106: 'END' ';' /
8107: ViewRules / CondRules / Rule .
8108: RulesAndCond = CondRules / Rule .
8109: ViewRules = 'IN' ViewID CondRuleSeq .
1.30 cvs 8110: CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
1.1 cvs 8111: CondRules / Rule .
1.30 cvs 8112: CondRules = CondRule < CondRule >
1.1 cvs 8113: [ 'Otherwise' RuleSeq ] .
8114: CondRule = 'IF' ConditionSeq RuleSeq .
1.30 cvs 8115: RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' / Rule .
1.1 cvs 8116:
1.30 cvs 8117: ConditionSeq = Condition < 'AND' Condition > .
1.6 cvs 8118: Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
8119: ConditionElem = 'First' / 'Last' /
8120: [ 'Immediately' ] 'Within' [ NumParent ]
8121: ElemID [ ExtStruct ] /
8122: ElemID /
8123: 'Referred' / 'FirstRef' / 'LastRef' /
8124: 'ExternalRef' / 'InternalRef' / 'CopyRef' /
8125: 'AnyAttributes' / 'FirstAttr' / 'LastAttr' /
8126: 'UserPage' / 'StartPage' / 'ComputedPage' /
8127: 'Empty' /
8128: '(' [ MinMax ] CounterName CounterCond ')' /
8129: CondPage '(' CounterID ')' .
8130: NumParent = [ GreaterLess ] NParent .
1.30 cvs 8131: GreaterLess = '>' / '<' .
1.6 cvs 8132: NParent = NUMBER.
1.30 cvs 8133: CounterCond = '<' MaxCtrVal / '>' MinCtrVal /
1.6 cvs 8134: '=' EqCtrVal /
8135: 'IN' '[' ['-'] MinCtrBound '..'
8136: ['-'] MaxCtrBound ']' .
8137: PageCond = 'Even' / 'Odd' / 'One' .
8138: MaxCtrVal = NUMBER .
8139: MinCtrVal = NUMBER .
8140: EqCtrVal = NUMBER .
8141: MaxCtrBound = NUMBER .
8142: MinCtrBound = NUMBER .
1.1 cvs 8143:
8144: Rule = PresParam ';' / PresFunc ';' .
8145: PresParam = 'VertRef' ':' HorizPosition /
8146: 'HorizRef' ':' VertPosition /
8147: 'VertPos' ':' VPos /
8148: 'HorizPos' ':' HPos /
8149: 'Height' ':' Extent /
8150: 'Width' ':' Extent /
8151: 'VertOverflow' ':' Boolean /
8152: 'HorizOverflow' ':' Boolean /
1.26 cvs 8153: 'MarginTop' ':' MarginWidth /
8154: 'MarginRight' ':' MarginWidth /
8155: 'MarginBottom' ':' MarginWidth /
8156: 'MarginLeft' ':' MarginWidth /
8157: 'PaddingTop' ':' PaddingWidth /
8158: 'PaddingRight' ':' PaddingWidth /
8159: 'PaddingBottom' ':' PaddingWidth /
8160: 'PaddingLeft' ':' PaddingWidth /
8161: 'BorderTopWidth' ':' BorderWidth /
8162: 'BorderRightWidth' ':' BorderWidth /
8163: 'BorderBottomWidth' ':' BorderWidth /
8164: 'BorderLeftWidth' ':' BorderWidth /
8165: 'BorderTopColor' ':' BorderColor /
8166: 'BorderRightColor' ':' BorderColor /
8167: 'BorderBottomColor' ':' BorderColor /
8168: 'BorderLeftColor' ':' BorderColor /
8169: 'BorderTopStyle' ':' BorderStyle /
8170: 'BorderRightStyle' ':' BorderStyle /
8171: 'BorderBottomStyle' ':' BorderStyle /
8172: 'BorderLeftStyle' ':' BorderStyle .
1.1 cvs 8173: 'LineSpacing' ':' DistOrInherit /
8174: 'Indent' ':' DistOrInherit /
8175: 'Adjust' ':' AlignOrInherit /
8176: 'Justify' ':' BoolInherit /
8177: 'Hyphenate' ':' BoolInherit /
8178: 'PageBreak' ':' Boolean /
8179: 'LineBreak' ':' Boolean /
8180: 'InLine' ':' Boolean /
8181: 'NoBreak1' ':' AbsDist /
8182: 'NoBreak2' ':' AbsDist /
8183: 'Gather' ':' Boolean /
8184: 'Visibility' ':' NumberInherit /
8185: 'Size' ':' SizeInherit /
8186: 'Font' ':' NameInherit /
8187: 'Style' ':' StyleInherit /
1.23 cvs 8188: 'Weight' ':' WeightInherit /
1.1 cvs 8189: 'Underline' ':' UnderLineInherit /
8190: 'Thickness' ':' ThicknessInherit /
8191: 'Depth' ':' NumberInherit /
8192: 'LineStyle' ':' LineStyleInherit /
8193: 'LineWeight' ':' DistOrInherit /
8194: 'FillPattern' ':' NameInherit /
1.30 cvs 8195: 'Background' ':' Color /
8196: 'Foreground' ':' Color /
1.1 cvs 8197: 'Content' ':' VarConst .
8198: PresFunc = Creation '(' BoxID ')' /
8199: 'Line' /
8200: 'NoLine' /
8201: 'Page' '(' BoxID ')' /
1.13 cvs 8202: 'Copy' '(' BoxTypeToCopy ')' /
8203: 'ShowBox' /
1.18 cvs 8204: 'BackgroundPicture' ':' FileName /
8205: 'PictureMode' ':' PictMode .
1.1 cvs 8206:
8207: BoxTypeToCopy = BoxID [ ExtStruct ] /
8208: ElemID [ ExtStruct ] .
8209: ExtStruct = '(' ElemID ')' .
8210:
8211: Distance = [ Sign ] AbsDist .
8212: Sign = '+' / '-' .
8213: AbsDist = IntegerOrAttr [ '.' DecimalPart ]
8214: [ Unit ] .
8215: IntegerOrAttr = IntegerPart / AttrID .
8216: IntegerPart = NUMBER .
8217: DecimalPart = NUMBER .
8218: Unit = 'em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
8219: 'pc' / 'px' / '%' .
8220:
8221: HPos = 'nil' / VertAxis '=' HorizPosition
8222: [ 'UserSpecified' ] .
8223: VPos = 'nil' / HorizAxis '=' VertPosition
8224: [ 'UserSpecified' ] .
8225: VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
8226: HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .
8227:
1.6 cvs 8228: VertPosition = Reference '.' HorizAxis [ Distance ] .
8229: HorizPosition = Reference '.' VertAxis [ Distance ] .
8230: Reference = 'Enclosing' [ BoxTypeNot ] /
8231: 'Enclosed' [ BoxTypeNot ] /
8232: 'Previous' [ BoxTypeNot ] /
8233: 'Next' [ BoxTypeNot ] /
8234: 'Referred' [ BoxTypeNot ] /
8235: 'Creator' /
8236: 'Root' /
8237: '*' /
8238: BoxOrType .
8239: BoxOrType = BoxID /
8240: [ '*' ] [ FirstSec ] ElemID /
1.17 cvs 8241: 'AnyElem' / 'AnyBox' /
8242: 'ElemWithAttr' AttrID .
1.6 cvs 8243: BoxTypeNot = [ 'NOT' ] BoxOrType .
8244:
8245: Extent = Reference '.' HeightWidth
8246: [ Relation ] [ 'Min' ] /
8247: AbsDist [ 'UserSpecified' ] [ 'Min' ] /
8248: HPos / VPos .
8249: HeightWidth = 'Height' / 'Width' .
8250: Relation = '*' ExtentAttr '%' / Distance .
8251: ExtentAttr = ExtentVal / AttrID .
8252: ExtentVal = NUMBER .
1.26 cvs 8253:
8254: MarginWidth = InheritParent / 'Auto' / Distance .
8255: PaddingWidth = InheritParent / Distance .
8256: BorderWidth = InheritParent / 'Thin' / 'Medium' / 'Thick' / Distance .
8257: BorderColor = InheritParent / 'Transparent' / 'Foreground' /
8258: ColorName .
8259: BorderStyle = InheritParent /
8260: 'None' / 'Hidden' / 'Dotted' / 'Dashed' / 'Solid' /
8261: 'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
1.27 cvs 8262: InheritParent = 'Enclosing' '=' / 'Creator' '=' .
1.26 cvs 8263: ColorName = NAME .
1.6 cvs 8264:
8265: Inheritance = Kinship InheritedValue .
8266: Kinship = 'Enclosing' / 'GrandFather'/ 'Enclosed' /
8267: 'Previous' / 'Creator' .
8268: InheritedValue = '+' PosIntAttr [ 'Max' maximumA ] /
8269: '-' NegIntAttr [ 'Min' minimumA ] /
8270: '=' .
8271: PosIntAttr = PosInt / AttrID .
8272: PosInt = NUMBER .
8273: NegIntAttr = NegInt / AttrID .
8274: NegInt = NUMBER .
8275: maximumA = maximum / AttrID .
8276: maximum = NUMBER .
8277: minimumA = minimum / AttrID .
8278: minimum = NUMBER .
8279:
8280: AlignOrInherit = Kinship '=' / Alignment .
8281: Alignment = 'Left' / 'Right' / 'VMiddle' /
8282: 'LeftWithDots' .
1.1 cvs 8283:
1.6 cvs 8284: DistOrInherit = Kinship InheritedDist / Distance .
8285: InheritedDist = '=' / '+' AbsDist / '-' AbsDist .
1.1 cvs 8286:
1.6 cvs 8287: BoolInherit = Boolean / Kinship '=' .
8288: Boolean = 'Yes' / 'No' .
1.1 cvs 8289:
1.6 cvs 8290: NumberInherit = Integer / AttrID / Inheritance .
8291: Integer = NUMBER .
1.1 cvs 8292:
8293: LineStyleInherit= Kinship '=' / 'Solid' / 'Dashed' /
8294: 'Dotted' .
8295:
1.6 cvs 8296: SizeInherit = SizeAttr [ 'pt' ] / Kinship InheritedSize .
8297: InheritedSize = '+' SizeAttr [ 'pt' ]
8298: [ 'Max' MaxSizeAttr ] /
8299: '-' SizeAttr [ 'pt' ]
8300: [ 'Min' MinSizeAttr ] /
1.22 cvs 8301: '*' PercentSizeAttr '%' /
1.6 cvs 8302: '=' .
8303: SizeAttr = Size / AttrID .
8304: Size = NUMBER .
8305: MaxSizeAttr = MaxSize / AttrID .
8306: MaxSize = NUMBER .
8307: MinSizeAttr = MinSize / AttrID .
8308: MinSize = NUMBER .
1.22 cvs 8309: PercentSizeAttr = PercentSize / AttrID .
8310: PercentSize = NUMBER .
1.6 cvs 8311:
8312: NameInherit = Kinship '=' / FontName .
8313: FontName = NAME .
1.30 cvs 8314: Color = 'Transparent' / Kinship '=' / FontName .
1.6 cvs 8315: StyleInherit = Kinship '=' /
1.23 cvs 8316: 'Roman' / 'Italics' / 'Oblique' .
8317: WeightInherit = Kinship '=' /
8318: 'Normal' / 'Bold' .
1.1 cvs 8319: UnderLineInherit= Kinship '=' /
1.6 cvs 8320: 'NoUnderline' / 'Underlined' /
8321: 'Overlined' / 'CrossedOut' .
1.1 cvs 8322: ThicknessInherit= Kinship '=' / 'Thick' / 'Thin' .
1.13 cvs 8323:
8324: FileName = STRING .
8325: PictMode = 'NormalSize' / 'Scale' /
8326: 'RepeatXY' / 'RepeatX' / 'RepeatY' .
1.1 cvs 8327:
1.6 cvs 8328: VarConst = ConstID / ConstType ConstValue /
8329: VarID / '(' FunctionSeq ')' /
8330: ElemID .
8331:
8332: Creation = Create [ 'Repeated' ] .
8333: Create = 'CreateFirst' / 'CreateLast' /
8334: 'CreateBefore' / 'CreateAfter' /
8335: 'CreateEnclosing' .
8336:
1.30 cvs 8337: TransmitSeq = Transmit < Transmit > .
1.6 cvs 8338: Transmit = TypeOrCounter 'To' ExternAttr
8339: '(' ElemID ')' ';' .
8340: TypeOrCounter = CounterID / ElemID .
8341: ExternAttr = NAME .
1.1 cvs 8342:
1.18 cvs 8343: END</pre>
8344: </div>
1.1 cvs 8345:
1.18 cvs 8346: <div class="section">
8347: <h2><a name="sectb64">The T language</a></h2>
8348: <pre>TransSchema = 'TRANSLATION' ElemID ';'
1.1 cvs 8349: [ 'LINELENGTH' LineLength ';' ]
8350: [ 'LINEEND' CHARACTER ';' ]
8351: [ 'LINEENDINSERT' STRING ';' ]
8352: [ 'BUFFERS' BufferSeq ]
8353: [ 'COUNTERS' CounterSeq ]
8354: [ 'CONST' ConstSeq ]
8355: [ 'VAR' VariableSeq ]
8356: 'RULES' ElemSeq
8357: [ 'ATTRIBUTES' AttrSeq ]
8358: [ 'PRESENTATION' PresSeq ]
1.30 cvs 8359: < 'TEXTTRANSLATE' TextTransSeq >
1.1 cvs 8360: [ 'SYMBTRANSLATE' TransSeq ]
8361: [ 'GRAPHTRANSLATE' TransSeq ]
8362: 'END' .
8363:
8364: LineLength = NUMBER .
8365:
1.30 cvs 8366: BufferSeq = Buffer < Buffer > .
1.1 cvs 8367: Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
8368: BufferID = NAME .
8369:
1.30 cvs 8370: CounterSeq = Counter < Counter > .
1.1 cvs 8371: Counter = CounterID [ ':' CounterFunc ] ';' .
8372: CounterID = NAME .
8373: CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
8374: [ 'Init' AttrID ] /
8375: 'Rlevel' 'of' ElemID /
8376: 'Set' InitValue 'On' ElemID
8377: 'Add' Increment 'On' ElemID
8378: [ 'Init' AttrID ] .
8379: SLevelAsc = [ '-' ] LevelAsc .
8380: LevelAsc = NUMBER .
8381: InitValue = NUMBER .
8382: Increment = NUMBER .
8383: ElemID = NAME .
8384: AttrID = NAME .
8385:
1.30 cvs 8386: ConstSeq = Const < Const > .
1.1 cvs 8387: Const = ConstID '=' ConstValue ';' .
8388: ConstID = NAME .
8389: ConstValue = STRING .
8390:
1.30 cvs 8391: VariableSeq = Variable < Variable > .
8392: Variable = VarID ':' Function < Function > ';' .
1.1 cvs 8393: VarID = NAME .
8394: Function = 'Value' '(' CounterID [ ':' Length ]
8395: [ ',' CounterStyle ] ')' /
8396: 'FileDir' / 'FileName' / 'Extension' /
8397: 'DocumentName' / 'DocumentDir' /
8398: ConstID / CharString /
8399: BufferID / AttrID .
8400: Length = NUMBER .
8401: CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
8402: 'Uppercase' / 'Lowercase' .
8403: CharString = STRING .
8404:
1.30 cvs 8405: ElemSeq = TransType < TransType > .
1.1 cvs 8406: TransType = [ FirstSec ] ElemID ':' RuleSeq .
8407: FirstSec = 'First' / 'Second' .
1.30 cvs 8408: RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
1.1 cvs 8409: Rule = SimpleRule / ConditionBlock .
8410: ConditionBlock= 'IF' ConditionSeq SimpleRuleSeq .
1.30 cvs 8411: SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
1.1 cvs 8412: SimpleRule .
8413:
8414: ConditionSeq = Condition [ 'AND' Condition ] .
8415: Condition = [ 'NOT' ] [ 'Target' ] Cond .
8416: Cond = CondElem / CondAscend .
8417: CondElem = 'FirstRef' / 'LastRef' /
8418: 'ExternalRef' /
8419: 'Defined' /
8420: 'Alphabet' '=' Alphabet /
8421: 'ComputedPage' / 'StartPage' /
8422: 'UserPage' / 'ReminderPage' /
8423: 'Empty' /
1.18 cvs 8424: ElemID /
1.1 cvs 8425: 'FirstAttr' / 'LastAttr' .
8426: CondAscend = [ Ascend ] CondOnAscend .
8427: Ascend = '*' / 'Parent' / 'Ancestor' LevelOrType .
8428: LevelOrType = CondRelLevel / ElemID [ ExtStruct ] .
8429: CondRelLevel = NUMBER .
8430: CondOnAscend = 'First' / 'Last' /
8431: 'Referred' /
8432: [ 'Immediately' ] 'Within' [ NumParent ]
8433: ElemID [ ExtStruct ] /
8434: 'Attributes' /
8435: AttrID [ RelatAttr ] /
8436: 'Presentation' /
8437: PresRule /
8438: 'Comment' .
8439: NumParent = [ GreaterLess ] NParent .
1.30 cvs 8440: GreaterLess = '>' / '<' .
1.1 cvs 8441: NParent = NUMBER.
8442: Alphabet = NAME .
8443: RelatAttr = '=' Value /
1.30 cvs 8444: '>' [ '-' ] Minimum /
1.1 cvs 8445: '<' [ '-' ] Maximum /
8446: 'IN' '[' [ '-' ] MinInterval '..'
8447: [ '-' ] MaxInterval ']' .
8448: Value = [ '-' ] IntegerVal / TextVal / AttrValue .
8449: Minimum = NUMBER .
8450: Maximum = NUMBER .
8451: MinInterval = NUMBER .
8452: MaxInterval = NUMBER .
8453: IntegerVal = NUMBER .
8454: TextVal = STRING .
8455: AttrValue = NAME .
8456:
8457: SimpleRule = 'Create' [ 'IN' VarID ] Object
8458: [ Position ] ';' /
8459: 'Write' Object [ Position ] ';' /
8460: 'Read' BufferID [ Position ] ';' /
8461: 'Include' File [ Position ] ';' /
1.6 cvs 8462: 'Get' [ RelPosition ] ElemID
8463: [ ExtStruct ]
8464: [ Position ] ';' /
1.1 cvs 8465: 'Copy' [ RelPosition ] ElemID
8466: [ ExtStruct ]
8467: [ Position ] ';' /
8468: 'Use' TrSchema [ 'For' ElemID ] ';' /
8469: 'Remove' ';' /
1.31 cvs 8470: 'Ignore' ';' /
1.1 cvs 8471: 'NoTranslation' ';' /
8472: 'NoLineBreak' ';' /
8473: 'ChangeMainFile' VarID [ Position ] ';' /
1.14 cvs 8474: 'RemoveFile' VarID [ Position ] ';' /
1.10 cvs 8475: 'Set' CounterID InitValue [ Position ] ';' /
8476: 'Add' CounterID Increment [ Position ] ';' /
1.25 cvs 8477: 'Indent' [ 'IN' VarID ] Indent [ Position ] ';' .
1.10 cvs 8478:
1.25 cvs 8479: Indent = 'Suspend' / 'Resume' / [ IndentSign ] IndentValue .
1.10 cvs 8480: IndentSign = '+' / '-' .
8481: IndentValue = NUMBER .
1.1 cvs 8482:
8483: Object = ConstID / CharString /
8484: BufferID /
8485: VarID /
1.30 cvs 8486: '(' Function < Function > ')' /
1.21 cvs 8487: [ 'Translated' ] AttrID /
1.1 cvs 8488: 'Value' /
8489: 'Content' /
8490: 'Comment' /
8491: 'Attributes' /
8492: 'Presentation' /
8493: 'RefId' /
8494: 'PairId' /
8495: 'FileDir' / 'FileName' / 'Extension' /
8496: 'DocumentName' / 'DocumentDir' /
8497: [ 'Referred' ] ReferredObject .
8498: Position = 'After' / 'Before' .
8499:
1.6 cvs 8500: ReferredObject= VarID /
8501: ElemID [ ExtStruct ] /
8502: 'RefId' /
8503: 'DocumentName' / 'DocumentDir' .
1.1 cvs 8504:
1.6 cvs 8505: File = FileName / BufferID .
8506: FileName = STRING .
1.1 cvs 8507:
1.6 cvs 8508: RelPosition = 'Included' / 'Referred' .
8509: ExtStruct = '(' ElemID ')' .
1.1 cvs 8510:
1.6 cvs 8511: TrSchema = NAME .
8512:
1.30 cvs 8513: AttrSeq = TransAttr < TransAttr > .
1.6 cvs 8514: TransAttr = AttrID [ '(' ElemID ')' ]
8515: [ RelatAttr ] ':' RuleSeq .
8516:
1.30 cvs 8517: PresSeq = PresTrans < PresTrans > .
1.6 cvs 8518: PresTrans = PresRule ':' RuleSeq .
8519: PresRule = 'Size' [ PresRelation ] /
8520: 'Indent' [ PresRelation ] /
8521: 'LineSpacing' [ PresRelation ] /
8522: 'Adjust' [ '=' AdjustVal ] /
8523: 'Justify' [ '=' BoolVal ] /
8524: 'Hyphenate' [ '=' BoolVal ] /
8525: 'Style' [ '=' StyleVal ] /
1.24 cvs 8526: 'Weight' [ '=' WeightVal ] /
1.6 cvs 8527: 'Font' [ '=' FontVal ] /
8528: 'UnderLine' [ '=' UnderLineVal ] /
8529: 'Thickness' [ '=' ThicknessVal ] /
8530: 'LineStyle' [ '=' LineStyleVal ] /
8531: 'LineWeight' [ PresRelation ] /
8532: 'FillPattern' [ '=' Pattern ] /
8533: 'Background' [ '=' Color ] /
8534: 'Foreground' [ '=' Color ] .
8535:
8536: PresRelation = '=' PresValue /
1.30 cvs 8537: '>' [ '-' ] PresMinimum /
1.6 cvs 8538: '<' [ '-' ] PresMaximum /
8539: 'IN' '[' [ '-' ] PresIntervalMin '..'
8540: [ '-' ] PresIntervalMax ']' .
8541: AdjustVal = 'Left' / 'Right' / 'VMiddle' /
8542: 'LeftWithDots' .
8543: BoolVal = 'Yes' / 'No' .
1.24 cvs 8544: StyleVal = 'Roman' / 'Italics' / 'Oblique' .
8545: WeightVal = 'Normal' / 'Bold' .
1.6 cvs 8546: FontVal = 'Times' / 'Helvetica' / 'Courier' .
8547: UnderLineVal = 'NoUnderline' / 'UnderLined' /
8548: 'OverLined' / 'CrossedOut' .
8549: ThicknessVal = 'Thick' / 'Thin' .
8550: LineStyleVal = 'Solid' / 'Dashed' / 'Dotted' .
8551: Pattern = NAME .
8552: Color = NAME .
8553: PresMinimum = NUMBER .
8554: PresMaximum = NUMBER .
1.1 cvs 8555: PresIntervalMin= NUMBER .
8556: PresIntervalMax= NUMBER .
1.6 cvs 8557: PresValue = [ '-' ] PresVal .
8558: PresVal = NUMBER .
1.1 cvs 8559:
1.6 cvs 8560: TextTransSeq = [ Alphabet ] TransSeq .
8561: Alphabet = NAME .
1.30 cvs 8562: TransSeq = 'BEGIN' < Translation > 'END' ';' /
1.6 cvs 8563: Translation .
1.30 cvs 8564: Translation = Source [ '->' Target ] ';' .
1.6 cvs 8565: Source = STRING .
1.18 cvs 8566: Target = STRING .</pre>
8567: </div>
8568: <hr>
8569: </div>
1.1 cvs 8570:
1.18 cvs 8571: <div class="chapter">
8572: <h1><a name="sect7">Character coding</a></h1>
1.1 cvs 8573:
1.18 cvs 8574: <div class="section">
1.30 cvs 8575: <h2><a name="sectb71">Characters</a></h2>
1.1 cvs 8576:
1.30 cvs 8577: <p>The characters of the Latin alphabet follow the encoding defined in the ISO
1.5 cvs 8578: 8859-1 (ISO Latin-1) standard. The characters of the Greek alphabet follow
1.18 cvs 8579: the encoding defined by Adobe for its Symbol font (Adobe FontSpecific).</p>
1.30 cvs 8580:
8581: <p>Characters whose octal code is greater than 0200 are written in the form of
1.1 cvs 8582: their octal code preceded by a backslash character (``\''). For example, the
1.30 cvs 8583: French word 'Résumé' is written <tt>R\351sum\351</tt>.</p>
8584:
8585: <p>To the ISO 8859-1 encoding four characters with the following codes have
8586: been added:<br>
1.18 cvs 8587: <tt>212</tt>: line break<br>
8588: <tt>240</tt>: sticky space<br>
8589: <tt>201</tt>: thin space<br>
8590: <tt>202</tt>: en space</p>
1.30 cvs 8591:
8592: <p>The <tt>212</tt> character is a ``line break'' character which forces a
8593: line break. The <tt>240</tt> character is a ``sticky space'', which cannot be
1.18 cvs 8594: replaced by a line break.</p>
8595: </div>
1.1 cvs 8596:
1.18 cvs 8597: <div class="section">
1.30 cvs 8598: <h2><a name="sectb72">Symbols</a></h2>
1.1 cvs 8599:
1.30 cvs 8600: <p>The table below gives the codes for the symbols of Thot. Symbols can be
8601: used in presentation schemas constants and in transcoding rules of translation
1.18 cvs 8602: schemas. Each symbol is represented by a single character.</p>
8603: <ul>
1.30 cvs 8604: <li><tt>r</tt>: a radical</li>
8605: <li><tt>i</tt>: a simple integral</li>
8606: <li><tt>c</tt>: a curvilinear integral</li>
8607: <li><tt>d</tt>: a double integral</li>
8608: <li><tt>t</tt>: a triple integral</li>
8609: <li><tt>S</tt>: the summation symbol</li>
8610: <li><tt>P</tt>: the product symbol</li>
8611: <li><tt>U</tt>: the union symbol</li>
8612: <li><tt>I</tt>: the intersection symbol</li>
8613: <li><tt>></tt>: a right arrow</li>
8614: <li><tt><</tt>: a left arrow</li>
8615: <li><tt>^</tt>: an up arrow</li>
8616: <li><tt>V</tt>: a down arrow</li>
8617: <li><tt>(</tt>: an opening parenthesis</li>
8618: <li><tt>)</tt>: a closing parenthesis</li>
8619: <li><tt>{</tt>: an opening brace</li>
8620: <li><tt>}</tt>: a closing brace</li>
8621: <li><tt>[</tt>: an opening bracket</li>
8622: <li><tt>]</tt>: a closing bracket</li>
1.18 cvs 8623: </ul>
8624: </div>
1.1 cvs 8625:
1.18 cvs 8626: <div class="section">
1.30 cvs 8627: <h2><a name="sectb73">Graphical elements</a></h2>
1.1 cvs 8628:
1.30 cvs 8629: <p>The table below gives the codes for the graphical elements of Thot. These
1.1 cvs 8630: elements can be used in presentation schemas constants and in transcoding
8631: rules of translation schemas. Each graphical element is represented by a
1.18 cvs 8632: single character.</p>
8633: <ul>
1.30 cvs 8634: <li>a: a circle</li>
8635: <li><p><tt>A</tt>: an open curve with an arrow head at the end</p>
8636: </li>
8637: <li><tt>b</tt>: a horizontal line along the lower side of the box</li>
8638: <li><tt>B</tt>: an open curve</li>
8639: <li><tt>c</tt>: an ellipse inscribed in the box</li>
8640: <li><tt>C</tt>: a rectangle with rounded corners</li>
8641: <li><tt>D</tt>: an open curve with two arrow heads</li>
8642: <li><tt>e</tt>: The northwest/southeast diagonal of the box with an
8643: arrowhead at the bottom</li>
8644: <li><tt>E</tt>: The southwest/northeast diagonal of the box with an
8645: arrowhead at the top</li>
8646: <li><tt>F</tt>: an open curve with an arrow head at start</li>
8647: <li><tt>g</tt>: a line from the origin of the box to its opposite
8648: corner</li>
8649: <li><tt>h</tt>: a horizontal line as wide as the box and placed in its
8650: middle</li>
8651: <li><tt>l</tt>: a vertical line on the left side of the box</li>
8652: <li><tt>L</tt>: a lozenge</li>
8653: <li><tt>M</tt>: an open broken line with two arrow heads</li>
8654: <li><tt>N</tt>: an open broken line with an arrow head at start</li>
8655: <li><tt>o</tt>: The southwest/northeast diagonal of the box with an
8656: arrowhead at the bottom</li>
8657: <li><tt>O</tt>: The northwest/southeast diagonal of the box with an
8658: arrowhead at the top</li>
8659: <li><tt>p</tt>: a polygon</li>
8660: <li><tt>P</tt>: a rectangle with round corners and a horizontal bar at the
8661: top</li>
8662: <li><tt>Q</tt>: an ellipse with a horizontal bar at the top</li>
8663: <li><tt>r</tt>: a vertical line on the right side of the box</li>
8664: <li><tt>R</tt>: a rectangle which is the shape of the box</li>
8665: <li><tt>s</tt>: a closed curve</li>
8666: <li><tt>S</tt>: an open broken line</li>
8667: <li><tt>t</tt>: a horizontal line along the upper side of the box</li>
8668: <li><tt>U</tt>: an open broken line with an arrow head at the end</li>
8669: <li><tt>v</tt>: a vertical line as tall as the box and placed in its
8670: middle</li>
8671: <li><tt>V</tt>: a down arrow as tall as the box and in its middle</li>
8672: <li>w: a segment (2 points)</li>
8673: <li><tt>W</tt>: the upper right corner</li>
8674: <li>x: a segment (2 points) with an arrow head at the end</li>
8675: <li><tt>X</tt>: the lower right corner</li>
8676: <li>y: a segment (2 points) with an arrow head at the end</li>
8677: <li><tt>Y</tt>: the lower left corner</li>
8678: <li>z: a segment (2 points) with an arrow head at the end</li>
8679: <li><tt>Z</tt>: the upper left corner</li>
8680: <li><tt>space</tt>: a transparent element</li>
8681: <li><tt>^</tt>: an up arrow as tall as the box and in its middle</li>
8682: <li><tt>></tt>: a right arrow as long as the box's width and in its
8683: middle</li>
8684: <li><tt>></tt>: a left arrow as long as the box's width and in its
8685: middle</li>
8686: <li><tt>/</tt>: The southwest/northeast diagonal of the box</li>
8687: <li><tt>\</tt>: the northwest/southeast diagonal of the box</li>
1.18 cvs 8688: </ul>
8689: <hr>
8690: </div>
8691: </div>
8692: </body>
8693: </html>
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