[comment {-*- tcl -*- doctools manpage}]
[manpage_begin doctools2idx_introduction n 2.0]
[copyright {2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>}]
[moddesc   {Documentation tools}]
[titledesc {DocTools - Keyword indices}]
[category  {Documentation tools}]
[keywords markup {semantic markup} index {keyword index}]
[keywords plugin parsing formatting conversion]
[see_also doctools2toc_introduction]
[see_also doctools2doc_introduction]
[comment {
    [see_also doctools_lang_intro]
    [see_also doctools_lang_syntax]
    [see_also doctools_lang_cmdref]
    [see_also doctools_lang_faq]
    [see_also doctools]
    [see_also doctools_plugin_apiref]
    [see_also doctoc_intro]
    [see_also docidx_intro]
}]
[description]

[term docidx] (short for [emph {documentation indices}]) stands for a
set of related, yet different, entities which are working together for
the easy creation and transformation of keyword indices for
documentation.

[para]

These are

[list_begin enumerated]
[enum]
A tcl based language for the semantic markup of a keyword index.
Markup is represented by Tcl commands.

Beginners should start with the
[manpage {docidx language introduction}].

The formal specification is split over two documents, one dealing with
the [manpage {docidx language syntax}], the other a
[manpage {docidx language command reference}].

[enum]
A set of packages for the programmatic manipulation of keyword indices
in memory, and their conversion between various formats, reading and
writing. The aforementioned markup language is one of the formats
which can be both read from and written to.

[enum]
The system for the conversion of indices is based on a plugin
mechanism, for this we have two APIs describing the interface between
the packages above and the import/export plugins.

[list_end]

[para]
Which of the more detailed documents are relevant to the reader of
this introduction depends on their role in the documentation process.

[para]

[list_begin enumerated]
[enum]
A [manpage writer] of documentation has to understand the markup language
itself. A beginner to docidx should read the more informally written
[manpage {docidx language introduction}] first. Having digested this
the formal [manpage {docidx language syntax}] specification should
become understandable. A writer experienced with docidx may only
need the [manpage {docidx language command reference}] from time to
time to refresh her memory.

[para]
While a document is written the [syscmd dtp] application can be used
to validate it, and after completion it also performs the conversion
into the chosen system of visual markup, be it *roff, HTML, plain
text, wiki, etc. The simpler [syscmd dtplite] application makes
internal use of docidx when handling directories of documentation,
automatically generating a proper keyword index for them.

[enum]
A [term processor] of documentation written in the [term docidx]
markup language has to know which tools are available for use.

[para]

The main tool is the aforementioned [syscmd dtp] application provided
by Tcllib. The simpler [syscmd dtplite] does not expose docidx to the
user. At the bottom level, common to both applications, however we
find the three packages providing the basic facilities to handle
keyword indices, i.e. import from textual formats, programmatic
manipulation in memory, and export to textual formats. These are

[list_begin definitions]
[def [package doctools::idx]]
Programmatic manipulation of keyword indices in memory.

[def [package doctools::idx::import]]
Import of keyword indices from various textual formats. The set of
supported formats is extensible through plugin packages.

[def [package doctools::idx::export]]
Export of keyword indices to various textual formats. The set of
supported formats is extensible through plugin packages.

[list_end]

See also section [sectref {Package Overview}] for an overview of the
dependencies between these and other, supporting packages.


[enum]
At last, but not least, [term {plugin writers}] have to understand the
interaction between the import and export packages and their plugins.
These APIs are described in the documentation for the two relevant
packages, i.e.

[list_begin itemized]
[item] [package doctools::idx::import]
[item] [package doctools::idx::export]
[list_end]

[list_end]

[section {Related formats}]

The docidx format does not stand alone, it has two companion formats.
These are called [term doctoc] and [term doctools], and they are
intended for the markup of [term {tables of contents}], and of general
documentation, respectively.

They are described in their own sets of documents, starting at
the [manpage {DocTools - Tables Of Contents}] and
the [manpage {DocTools - General}], respectively.


[section {Package Overview}]
[include include/dependencies.inc]


[vset CATEGORY doctools]
[include ../doctools2base/include/feedback.inc]
[manpage_end]