1doctools_lang_intro(n) Documentation tools doctools_lang_intro(n)
2______________________________________________________________________________
6
8 doctools_lang_intro - doctools language introduction
9
11 This document is an informal introduction to version 1 of the doctools
12 markup language based on a multitude of examples. After reading this a
13 writer should be ready to understand the two parts of the formal speci‐
14 fication, i.e. the doctools language syntax specification and the doc‐
15 tools language command reference.
16 FUNDAMENTALS
18 In the broadest terms possible the doctools markup language is LaTeX-
19 like, instead of like SGML and similar languages. A document written in
20 this language consists primarily of text, with markup commands embedded
21 into it.
22 Each markup command is a Tcl command surrounded by a matching pair of [
24 and ]. Inside of these delimiters the usual rules for a Tcl command
25 apply with regard to word quotation, nested commands, continuation
26 lines, etc. I.e.
27 ... [list_begin enumerated] ...
29 ... [call [cmd foo] \\
33 [arg bar]] ...
34 ... [term {complex concept}] ...
38 ... [opt "[arg key] [arg value]"] ...
42 BASIC STRUCTURE
45 The most simple document which can be written in doctools is
46 [manpage_begin NAME SECTION VERSION]
49 [see_also doctools_intro]
50 [see_also doctools_lang_cmdref]
51 [see_also doctools_lang_faq]
52 [see_also doctools_lang_syntax]
53 [keywords {doctools commands}]
54 [keywords {doctools language}]
55 [keywords {doctools markup}]
56 [keywords {doctools syntax}]
57 [keywords markup]
58 [keywords {semantic markup}]
59 [description]
60 [vset CATEGORY doctools]
61 [include ../doctools2base/include/feedback.inc]
62 [manpage_end]
63 This also shows us that all doctools documents are split into two
65 parts, the header and the body. Everything coming before [description]
66 belongs to the header, and everything coming after belongs to the body,
67 with the whole document bracketed by the two manpage_* commands. Before
68 and after these opening and closing commands we have only whitespace.
69 In the remainder of this section we will discuss only the contents of
71 the header, the structure of the body will be discussed in the section
72 Text structure.
73 The header section can be empty, and otherwise may contain only an
75 arbitrary sequence of the four so-called header commands, plus white‐
76 space. These commands are
77 titledesc
79 moddesc
81 require
83 copyright
85 They provide, through their arguments, additional information about the
87 document, like its title, the title of the larger group the document
88 belongs to (if applicable), the requirements of the documented packages
89 (if applicable), and copyright assignments. All of them can occur mul‐
90 tiple times, including none, and they can be used in any order. How‐
91 ever for titledesc and moddesc only the last occurrence is taken. For
92 the other two the specified information is accumulated, in the given
93 order. Regular text is not allowed within the header.
94 Given the above a less minimal example of a document is
96 [manpage_begin NAME SECTION VERSION]
99 [copyright {YEAR AUTHOR}]
110 [titledesc TITLE]
111 [moddesc MODULE_TITLE]
112 [require PACKAGE VERSION]
113 [require PACKAGE]
114 [description]
115 [manpage_end]
116 Remember that the whitespace is optional. The document
118 [manpage_begin NAME SECTION VERSION]
121 [see_also doctools_intro]
122 [see_also doctools_lang_cmdref]
123 [see_also doctools_lang_faq]
124 [see_also doctools_lang_syntax]
125 [keywords {doctools commands}]
126 [keywords {doctools language}]
127 [keywords {doctools markup}]
128 [keywords {doctools syntax}]
129 [keywords markup]
130 [keywords {semantic markup}]
131 [copyright {YEAR AUTHOR}][titledesc TITLE][moddesc MODULE_TITLE]
132 [require PACKAGE VERSION][require PACKAGE][description]
133 [vset CATEGORY doctools]
134 [include ../doctools2base/include/feedback.inc]
135 [manpage_end]
136 has the same meaning as the example before.
138 On the other hand, if whitespace is present it consists not only of any
140 sequence of characters containing the space character, horizontal and
141 vertical tabs, carriage return, and newline, but it may contain comment
142 markup as well, in the form of the comment command.
143 [comment { ... }]
146 [manpage_begin NAME SECTION VERSION]
147 [copyright {YEAR AUTHOR}]
158 [titledesc TITLE]
159 [moddesc MODULE_TITLE][comment { ... }]
160 [require PACKAGE VERSION]
161 [require PACKAGE]
162 [description]
163 [manpage_end]
164 [comment { ... }]
165 ADVANCED STRUCTURE
168 In the simple examples of the last section we fudged a bit regarding
169 the markup actually allowed to be used before the manpage_begin command
170 opening the document.
171 Instead of only whitespace the two templating commands include and vset
173 are also allowed, to enable the writer to either set and/or import con‐
174 figuration settings relevant to the document. I.e. it is possible to
175 write
176 [include FILE]
179 [vset VAR VALUE]
180 [manpage_begin NAME SECTION VERSION]
181 [description]
192 [manpage_end]
193 Even more important, these two commands are allowed anywhere where a
195 markup command is allowed, without regard for any other structure. I.e.
196 for example in the header as well.
197 [manpage_begin NAME SECTION VERSION]
200 [include FILE]
211 [vset VAR VALUE]
212 [description]
213 [manpage_end]
214 The only restriction include has to obey is that the contents of the
216 included file must be valid at the place of the inclusion. I.e. a file
217 included before manpage_begin may contain only the templating commands
218 vset and include, a file included in the header may contain only header
219 commands, etc.
220 TEXT STRUCTURE
222 The body of the document consists mainly of text, possibly split into
223 sections, subsections, and paragraphs, with parts marked up to high‐
224 light various semantic categories of text, and additional structure
225 through the use of examples and (nested) lists.
226 This section explains the high-level structural commands, with every‐
228 thing else deferred to the following sections.
229 The simplest way of structuring the body is through the introduction of
231 paragraphs. The command for doing so is para. Each occurrence of this
232 command closes the previous paragraph and automatically opens the next.
233 The first paragraph is automatically opened at the beginning of the
234 body, by description. In the same manner the last paragraph automati‐
235 cally ends at manpage_end.
236 [manpage_begin NAME SECTION VERSION]
239 [description]
250 ...
251 [para]
252 ...
253 [para]
254 ...
255 [manpage_end]
256 Empty paragraphs are ignored.
258 A structure coarser than paragraphs are sections, which allow the
260 writer to split a document into larger, and labeled, pieces. The com‐
261 mand for doing so is section. Each occurrence of this command closes
262 the previous section and automatically opens the next, including its
263 first paragraph. The first section is automatically opened at the
264 beginning of the body, by description (This section is labeled
265 "DESCRIPTION"). In the same manner the last section automatically ends
266 at manpage_end.
267 Empty sections are not ignored. We are free to (not) use paragraphs
269 within sections.
270 [manpage_begin NAME SECTION VERSION]
273 [description]
284 ...
285 [section {Section A}]
286 ...
287 [para]
288 ...
289 [section {Section B}]
290 ...
291 [manpage_end]
292 Between sections and paragraphs we have subsections, to split sections.
294 The command for doing so is subsection. Each occurrence of this command
295 closes the previous subsection and automatically opens the next,
296 including its first paragraph. A subsection is automatically opened at
297 the beginning of the body, by description, and at the beginning of each
298 section. In the same manner the last subsection automatically ends at
299 manpage_end.
300 Empty subsections are not ignored. We are free to (not) use paragraphs
302 within subsections.
303 [manpage_begin NAME SECTION VERSION]
306 [description]
317 ...
318 [section {Section A}]
319 ...
320 [subsection {Sub 1}]
321 ...
322 [para]
323 ...
324 [subsection {Sub 2}]
325 ...
326 [section {Section B}]
327 ...
328 [manpage_end]
329 TEXT MARKUP
332 Having handled the overall structure a writer can impose on the docu‐
333 ment we now take a closer at the text in a paragraph.
334 While most often this is just the unadorned content of the document we
336 do have situations where we wish to highlight parts of it as some type
337 of thing or other, like command arguments, command names, concepts,
338 uris, etc.
339 For this we have a series of markup commands which take the text to
341 highlight as their single argument. It should be noted that while their
342 predominant use is the highlighting of parts of a paragraph they can
343 also be used to mark up the arguments of list item commands, and of
344 other markup commands.
345 The commands available to us are
347 arg Its argument is a the name of a command argument.
349 class Its argument is a class name.
351 cmd Its argument is a command name (Tcl command).
353 const Its argument is a constant.
355 emph General, non-semantic emphasis.
357 file Its argument is a filename / path.
359 fun Its argument is a function name.
361 method Its argument is a method name
363 namespace
365 Its argument is namespace name.
366 opt Its argument is some optional syntax element.
368 option Its argument is a command line switch / widget option.
370 package
372 Its argument is a package name.
373 sectref
375 Its argument is the title of a section or subsection, i.e. a
376 section reference.
377 syscmd Its argument is a command name (external, system command).
379 term Its argument is a concept, or general terminology.
381 type Its argument is a type name.
383 uri Its argument is a uniform resource identifier, i.e an external
385 reference. A second argument can be used to specify an explicit
386 label for the reference in question.
387 usage The arguments describe the syntax of a Tcl command.
389 var Its argument is a variable.
391 widget Its argument is a widget name.
393 The example demonstrating the use of text markup is an excerpt from the
395 doctools language command reference, with some highlighting added. It
396 shows their use within a block of text, as the arguments of a list item
397 command (call), and our ability to nest them.
398 ...
401 [call [cmd arg_def] [arg type] [arg name]] [opt [arg mode]]]
402 Text structure. List element. Argument list. Automatically closes the
404 previous list element. Specifies the data-[arg type] of the described
405 argument of a command, its [arg name] and its i/o-[arg mode]. The
406 latter is optional.
407 ...
408 ESCAPES
411 Beyond the 20 commands for simple markup shown in the previous section
412 we have two more available which are technically simple markup. How‐
413 ever their function is not the marking up of phrases as specific types
414 of things, but the insertion of characters, namely [ and ]. These com‐
415 mands, lb and rb respectively, are required because our use of [ and ]
416 to bracket markup commands makes it impossible to directly use [ and ]
417 within the text.
418 Our example of their use are the sources of the last sentence in the
420 previous paragraph, with some highlighting added.
421 ...
424 These commands, [cmd lb] and [cmd lb] respectively, are required
425 because our use of [lb] and [rb] to bracket markup commands makes it
426 impossible to directly use [lb] and [rb] within the text.
427 ...
428 CROSS-REFERENCES
431 The last two commands we have to discuss are for the declaration of
432 cross-references between documents, explicit and implicit. They are
433 keywords and see_also. Both take an arbitrary number of arguments, all
434 of which have to be plain unmarked text. I.e. it is not allowed to use
435 markup on them. Both commands can be used multiple times in a document.
436 If that is done all arguments of all occurrences of one of them are put
437 together into a single set.
438 keywords
440 The arguments of this command are interpreted as keywords
441 describing the document. A processor can use this information to
442 create an index indirectly linking the containing document to
443 all documents with the same keywords.
444 see_also
446 The arguments of this command are interpreted as references to
447 other documents. A processor can format them as direct links to
448 these documents.
449 All the cross-reference commands can occur anywhere in the document
451 between manpage_begin and manpage_end. As such the writer can choose
452 whether she wants to have them at the beginning of the body, or at its
453 end, maybe near the place a keyword is actually defined by the main
454 content, or considers them as meta data which should be in the header,
455 etc.
456 Our example shows the sources for the cross-references of this docu‐
458 ment, with some highlighting added. Incidentally they are found at the
459 end of the body.
460 ...
463 [see_also doctools_intro]
464 [see_also doctools_lang_syntax]
465 [see_also doctools_lang_cmdref]
466 [keywords markup {semantic markup}]
467 [keywords {doctools markup} {doctools language}]
468 [keywords {doctools syntax} {doctools commands}]
469 [manpage_end]
470 EXAMPLES
473 Where ever we can write plain text we can write examples too. For sim‐
474 ple examples we have the command example which takes a single argument,
475 the text of the argument. The example text must not contain markup. If
476 we wish to have markup within an example we have to use the 2-command
477 combination example_begin / example_end instead.
478 The first opens an example block, the other closes it, and in between
480 we can write plain text and use all the regular text markup commands.
481 Note that text structure commands are not allowed. This also means that
482 it is not possible to embed examples and lists within an example. On
483 the other hand, we can use templating commands within example blocks to
484 read their contents from a file (Remember section Advanced structure).
485 The source for the very first example in this document (see section
487 Fundamentals), with some highlighting added, is
488 [example {
491 ... [list_begin enumerated] ...
492 }]
493 Using example_begin / example_end this would look like
495 [example_begin]
498 ... [list_begin enumerated] ...
499 [example_end]
500 LISTS
503 Where ever we can write plain text we can write lists too. The main
504 commands are list_begin to start a list, and list_end to close one. The
505 opening command takes an argument specifying the type of list started
506 it, and this in turn determines which of the eight existing list item
507 commands are allowed within the list to start list items.
508 After the opening command only whitespace is allowed, until the first
510 list item command opens the first item of the list. Each item is a reg‐
511 ular series of paragraphs and is closed by either the next list item
512 command, or the end of the list. If closed by a list item command this
513 command automatically opens the next list item. A consequence of a list
514 item being a series of paragraphs is that all regular text markup can
515 be used within a list item, including examples and other lists.
516 The list types recognized by list_begin and their associated list item
518 commands are:
519 arguments
521 (arg_def) This opens an argument (declaration) list. It is a
522 specialized form of a term definition list where the term is an
523 argument name, with its type and i/o-mode.
524 commands
526 (cmd_def) This opens a command (declaration) list. It is a spe‐
527 cialized form of a term definition list where the term is a com‐
528 mand name.
529 definitions
531 (def and call) This opens a general term definition list. The
532 terms defined by the list items are specified through the argu‐
533 ment(s) of the list item commands, either general terms, possi‐
534 bly with markup (def), or Tcl commands with their syntax (call).
535 enumerated
537 (enum) This opens a general enumerated list.
538 itemized
540 (item) This opens a general itemized list.
541 options
543 (opt_def) This opens an option (declaration) list. It is a spe‐
544 cialized form of a term definition list where the term is an
545 option name, possibly with the option's arguments.
546 tkoptions
548 (tkoption_def) This opens a widget option (declaration) list. It
549 is a specialized form of a term definition list where the term
550 is the name of a configuration option for a widget, with its
551 name and class in the option database.
552 Our example is the source of the definition list in the previous para‐
554 graph, with most of the content in the middle removed.
555 ...
558 [list_begin definitions]
559 [def [const arg]]
560 ([cmd arg_def]) This opens an argument (declaration) list. It is a
562 specialized form of a definition list where the term is an argument
563 name, with its type and i/o-mode.
564 [def [const itemized]]
566 ([cmd item])
568 This opens a general itemized list.
569 ...
571 [def [const tkoption]]
572 ([cmd tkoption_def]) This opens a widget option (declaration) list. It
574 is a specialized form of a definition list where the term is the name
575 of a configuration option for a widget, with its name and class in the
576 option database.
577 [list_end]
579 ...
580 Note that a list cannot begin in one (sub)section and end in another.
582 Differently said, (sub)section breaks are not allowed within lists and
583 list items. An example of this illegal construct is
584 ...
587 [list_begin itemized]
588 [item]
589 ...
590 [section {ILLEGAL WITHIN THE LIST}]
591 ...
592 [list_end]
593 ...
594
597 Now that this document has been digested the reader, assumed to be a
598 writer of documentation should be fortified enough to be able to under‐
599 stand the formal doctools language syntax specification as well. From
600 here on out the doctools language command reference will also serve as
601 the detailed specification and cheat sheet for all available commands
602 and their syntax.
603 To be able to validate a document while writing it, it is also recom‐
605 mended to familiarize oneself with one of the applications for the pro‐
606 cessing and conversion of doctools documents, i.e. either Tcllib's easy
607 and simple dtplite, or Tclapps' ultra-configurable dtp.
608
610 This document, and the package it describes, will undoubtedly contain
611 bugs and other problems. Please report such in the category doctools
612 of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
613 also report any ideas for enhancements you may have for either package
614 and/or documentation.
615 When proposing code changes, please provide unified diffs, i.e the out‐
617 put of diff -u.
618 Note further that attachments are strongly preferred over inlined
620 patches. Attachments can be made by going to the Edit form of the
621 ticket immediately after its creation, and then using the left-most
622 button in the secondary navigation bar.
623
625 doctools_intro, doctools_lang_cmdref, doctools_lang_faq, doc‐
626 tools_lang_syntax
627
629 doctools commands, doctools language, doctools markup, doctools syntax,
630 markup, semantic markup
631
633 Documentation tools
634
636 Copyright (c) 2007 Andreas Kupries <andreas_kupries@users.sourceforge.net>
637tcllib 1.0 doctools_lang_intro(n)