docidx_lang_intro(n)          Documentation tools         docidx_lang_intro(n)



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NAME
       docidx_lang_intro - docidx language introduction

DESCRIPTION
       This document is an informal introduction to version 1 of the docidx
       markup language based on a multitude of examples. After reading this a
       writer should be ready to understand the two parts of the formal
       specification, i.e. the docidx language syntax specification and the
       docidx language command reference.

   FUNDAMENTALS
       While the docidx markup language is quite similar to the doctools
       markup language, in the broadest terms possible, there is one key
       difference. An index consists essentially only of markup commands, with
       no plain text interspersed between them, except for whitespace.

       Each markup command is a Tcl command surrounded by a matching pair of [
       and ]. Inside of these delimiters the usual rules for a Tcl command
       apply with regard to word quotation, nested commands, continuation
       lines, etc. I.e.

                  ... [key {markup language}] ...



                ... [manpage thefile \\
                        {file description}] ...


   BASIC STRUCTURE
       The most simple document which can be written in docidx is


                  [index_begin GROUPTITLE TITLE]
                  [index_end]


       Not very useful, but valid. This also shows us that all docidx
       documents consist of only one part where we will list all keys and
       their references.

       A more useful index will contain at least keywords, or short 'keys',
       i.e. the phrases which were indexed. So:


              [index_begin GROUPTITLE TITLE]
              [key markup]
              [key {semantic markup}]]
              [key {docidx markup}]
              [key {docidx language}]
              [key {docidx commands}]
              [index_end]


       In the above example the command key is used to declare the keyword
       phrases we wish to be part of the index.

       However a truly useful index does not only list the keyword phrases,
       but will also contain references to documents associated with the
       keywords. Here is a made-up index for all the manpages in the module
       base64:


              [index_begin tcllib/base64 {De- & Encoding}]
              [key base64]
              [manpage base64]
              [key encoding]
              [manpage base64]
              [manpage uuencode]
              [manpage yencode]
              [key uuencode]
              [manpage uuencode]
              [key yEnc]
              [manpage yencode]
              [key ydecode]
              [manpage yencode]
              [key yencode]
              [manpage yencode]
              [index_end]


       In the above example the command manpage is used to insert references
       to documents, using symbolic file names, with each command belonging to
       the last key command coming before it.

       The other command to insert references is url. In contrast to manpage
       it uses explicit (possibly format-specific) urls to describe the
       location of the referenced document. As such this command is intended
       for the creation of references to external documents which could not be
       handled in any other way.

   ADVANCED STRUCTURE
       In all previous examples we fudged a bit regarding the markup actually
       allowed to be used before the index_begin command opening the document.

       Instead of only whitespace the two templating commands include and vset
       are also allowed, to enable the writer to either set and/or import
       configuration settings relevant to the table of contents. I.e. it is
       possible to write


              [include FILE]
              [vset VAR VALUE]
              [index_begin GROUPTITLE TITLE]
              [index_end]

       Even more important, these two commands are allowed anywhere where a
       markup command is allowed, without regard for any other structure.


              [index_begin GROUPTITLE TITLE]
              [include FILE]
              [vset VAR VALUE]
              [index_end]

       The only restriction include has to obey is that the contents of the
       included file must be valid at the place of the inclusion. I.e. a file
       included before index_begin may contain only the templating commands
       vset and include, a file included after a key may contain only manape
       or url references, and other keys, etc.

   ESCAPES
       Beyond the 6 commands shown so far we have two more available.  However
       their function is not the marking up of index structure, but the
       insertion of characters, namely [ and ].  These commands, lb and rb
       respectively, are required because our use of [ and ] to bracket markup
       commands makes it impossible to directly use [ and ] within the text.

       Our example of their use are the sources of the last sentence in the
       previous paragraph, with some highlighting added.


                ...
                These commands, [cmd lb] and [cmd lb] respectively, are required
                because our use of [lb] and [rb] to bracket markup commands makes it
                impossible to directly use [lb] and [rb] within the text.
                ...


FURTHER READING
       Now that this document has been digested the reader, assumed to be a
       writer of documentation should be fortified enough to be able to
       understand the formal docidx language syntax specification as well.
       From here on out the docidx language command reference will also serve
       as the detailed specification and cheat sheet for all available
       commands and their syntax.

       To be able to validate a document while writing it, it is also
       recommended to familiarize oneself with Tclapps' ultra-configurable
       dtp.

       On the other hand, docidx is perfectly suited for the automatic
       generation from doctools documents, and this is the route Tcllib's easy
       and simple dtplite goes, creating an index for a set of documents
       behind the scenes, without the writer having to do so on their own.

BUGS, IDEAS, FEEDBACK
       This document, will undoubtedly contain bugs and other problems.
       Please report such in the category doctools of the Tcllib SF Trackers
       [http://sourceforge.net/tracker/?group_id=12883].  Please also report
       any ideas for enhancements you may have.

SEE ALSO
       docidx_intro, docidx_lang_cmdref, docidx_lang_syntax

KEYWORDS
       docidx commands, docidx language, docidx markup, docidx syntax, markup,
       semantic markup

CATEGORY
       Documentation tools

COPYRIGHT
       Copyright (c) 2007-2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>




doctools                              1.0                 docidx_lang_intro(n)
