.. -*- coding: utf-8 -*-

========================================
   Emacs Support for reStructuredText
========================================

:Author: Martin Blais <blais@furius.ca>
:Date: $Date: 2005-11-18 05:26:30 +0100 (Fri, 18 Nov 2005) $
:Abstract:

    High-level description of the existing emacs support for editing
    reStructuredText text documents.  Suggested setup code and usage
    instructions are provided.

.. contents::


Introduction
============

reStructuredText_ is a series of conventions that allows a
toolset--docutils--to extract generic document structure from simple
text files.  For people who use Emacs_, there is a package that adds
some support for the conventions that reStructuredText_ specifies:
``rst.el``.

This document describes the most important features that it provides,
how to setup your emacs to use them and how to invoke them.


Basic Setup
===========

The emacs support is completely provided by the ``rst.el`` emacs
package.  In order to use these features, you need to put the file in
your emacs load-path, and to load it with::

  (require 'rst)  ;; or (load "rst")

Additional configuration variables can be customized and can be found
by browsing the source code for ``rst.el``.

Then you will want to bind keys to the most common commands it
provides.  A standard text-mode hook function is maintained and
provided by the package for this use, set it up like this::

  (add-hook 'text-mode-hook 'rst-text-mode-bindings)

A prefix map is defined for all the ``rst.el`` commands.  By default,
it is bound to the mode-specific-map and ``p``, e.g. ``C-c p ...``.


Section Decoration Adjustment
=============================

The rst package does not completely parse all the reStructuredText_
constructs, but it contains the ability to recognize the section
decorations and to build the hierarchy of the document.  What we call
section decorations or adornments are the underlines or under- and
overlines used to mark a section title.

There is a function that helps a great deal to maintain these
decorations: ``rst-adjust`` (bound on ``C-c p a``, ``C-c p =`` or
``C-=`` by default).  This function is a Swiss army knife that can be
invoked repeatedly and whose behaviour depends on context:

#. If there is an incomplete underline, e.g.::

      My Section Title
      ^^

   Invocation will complete the section title.  You can simply enter a
   few characters of the title and invoke the function to complete it.
   It can also be used to adjust the length of the existing decoration
   when you need to edit the title.

#. If there is no section decoration, a decoration one level under the
   last encountered section level is added;

#. If there is already a section decoration, it is promoted to the
   next level.  You can invoke it like this repeatedly to cycle the
   title through the hierarchy of existing decorations.

Invoking the function with a negative prefix argument, e.g. ``C--
C-=``, will effectively reverse the direction of decoration cycling.
To alternate between underline-only and over-and-under styles, you can
use a regular prefix argument, e.g. ``C-u C-=``.  See the
documentation of ``rst-adjust`` for more description of the prefix
arguments to alter the behaviour of the function.


Promoting and Demoting Many Sections
------------------------------------

When you are re-organizing the structure of a document, it can be
useful to change the level of a number of section titles.  The same
key binding can be used to do that: if the region is active when the
binding is invoked, all the section titles that are within the region
are promoted accordingly (or demoted, with negative prefix arg).


Customizations
--------------

You can set the variable ``rst-preferred-decorations`` to a list of
the decorations that you like to use for documents.  Everyone has
their preference.  ``rst-default-indent`` can be set to the number of
indent spaces preferred for the over-and-under decoration style.


Viewing the Hierarchy of Section Decorations
============================================

You can visualize the hierarchy of the section decorations in the
current buffer by invoking ``rst-display-decorations-hierarchy``,
bound on ``C-c p h``.  A temporary buffer will appear with fake
section titles rendered in the style of the current document.  This
can be useful when editing other people's documents to find out which
section decorations correspond to which levels.


Table of Contents
=================

When you are editing long documents, it can be a bit difficult to
orient yourself in the structure of your text.  To that effect, a
function is provided that quickly parses the document and presents a
hierarchically indented table of contents of the document in a
temporary buffer, in which you can navigate and press ``Return`` to go
to a specific section.

Invoke this function (``rst-toc``) with ``C-c p t``.  It should
present a temporary buffer that looks something like this::

  Table of Contents: 
  Debugging Meta-Techniques
    Introduction
    Debugging Solution Patterns
      Recognize That a Bug Exists
      Subdivide and Isolate
      Identify and Verify Assumptions
      Use a Tool for Introspection
      Change one thing at a time
      Learn about the System
    Understanding a bug
    The Basic Steps in Debugging
    Attitude
      Bad Feelings
      Good Feelings
    References

When you select a section title, the temporary buffer disappears and
you are left with the cursor positioned at the chosen section.


Inserting a Table of Contents
-----------------------------

Oftentimes in long text documents that are meant to be read directly,
a Table of Contents is inserted at the beginning of the text.  This is
the case for most internet FAQs, for example.  In reStructuredText_
documents, since the table of contents is automatically generated by
the parser with the ``.. contents::`` directive, people generally have
not been adding a text table of contents to their source documents,
and partly because it is too much trouble to edit and maintain.

The emacs support for reStructuredText_ provides a function to insert
such a table of contents in your document.  Since it is not meant to
be part of the document text, you should place such a table of
contents within a comment, so that it is ignored by the parser.  This
is the favoured usage::

  .. contents::
  .. 
      1  Introduction
      2  Debugging Solution Patterns
        2.1  Recognize That a Bug Exists
        2.2  Subdivide and Isolate
        2.3  Identify and Verify Assumptions
        2.4  Use a Tool for Introspection
        2.5  Change one thing at a time
        2.6  Learn about the System
      3  Understanding a bug
      4  The Basic Steps in Debugging
      5  Attitude
        5.1  Bad Feelings
        5.2  Good Feelings
      6  References

Just place the cursor at the top-left corner where you want to insert
the TOC and invoke the function with ``C-c p i``.  The table of
contents will display all the section titles that are under the
location where the insertion occurs.  This way you can insert local
table of contents by placing them in the appropriate location.

If you have deep nesting of sections, you can use a numeric prefix
argument to limit the depth of rendering of the TOC.

You can also customize the look of the TOC by setting the values of
the following variables:: ``rst-toc-indent``,
``rst-toc-insert-style``, ``rst-toc-insert-max-level``.


Maintaining the Table of Contents Up-to-date
--------------------------------------------

One issue is that you will probably want to maintain the inserted
table of contents up-to-date.  There is a function that will
automatically look for the inserted TOC (``rst-toc-insert-update``)
and it can be added to a hook on the section decoration adjustment
function, so that every time you adjust a section title, the TOC is
updated. Add this functionality with the following emacs
configuration::

  (add-hook 'rst-adjust-hook 'rst-toc-insert-update)

You can invoke the update on the current buffer with ``C-c p u``.


Navigating Between the Section Titles
=====================================

You can move the cursor between the different sections by using the
``rst-backward-section`` and ``rst-forward-section`` functions, by
default bound to the ``C-c p p`` and ``C-c p n`` keys (also ``C-c
C-p`` and ``C-c C-n``).


Shifting Bullet List Levels
===========================

Due to the nature of reStructuredText_, bullet lists are always
indented by two characters (unless they are part of a blockquote),
e.g. ::

   - Fruits

     - Bananas
     - Apples
     - Oranges

   - Veggies

     - Zucchini
     - Chick Peas

To this effect, when re-organizing bullet lists, it can be useful to
shift regions of text by indents of two characters.  You can use the
``C-c C-r`` and ``C-c C-l`` to shift the current region.  These
bindings are similar to the ones provided by python-mode for editing
python code and behave similarly.


Major Mode for Editing reStructuredText Documents
=================================================

There is a major mode available for editing and syntax highlighting
reStructuredText_ constructs.  This mode was written by Stefan Merten
[#]_.  It mostly provides lazy syntax coloring for many of the
constructs that reStructuredText_ prescribes.

To enable this mode, type ``M-x rst-mode`` or you can set up an
``auto-mode-alist`` to automatically turn it on whenever you visit
reStructuredText_ documents::

   (add-to-list 'auto-mode-alist '("\\.rst$" . rst-mode) )

If have local variables enabled (see ``enable-local-variables`` in the
Emacs manual), you can also add the following at the top of your
documents to trigger rst-mode::

   .. -*- mode: rst -*-

Or add this at the end of your documents::

   ..
      Local Variables:
      mode: rst
      End:

By default, the font-lock colouring is performed lazily.  If you don't
like this, you can turn this off by setting the value of
``rst-mode-lazy``.  You can also change the various colours (see the
source file for the whole list of customizable faces).

.. [#] This mode used to be provided by the file ``rst-mode.el`` and
   has now been integrated with the rest of the emacs code.


Converting Documents from Emacs
===============================

At the moment there is minimal support for calling the conversion
tools from within Emacs.  You can add a key binding like this to
invoke it::

  (local-set-key [(control c)(?9)] 'rst-compile)

This function basically creates a compilation command with the correct
output name for the current buffer and then invokes Emacs' compile
function.  It also looks for the presence of a ``docutils.conf``
configuration file in the parent directories and adds it to the
cmdline options.  You can customize which tool is used to perform the
conversion and some standard options to always be added as well.

Invocation uses the toolset indicated by
``rst-compile-primary-toolset`` (default is ``'html``).  Invocation
with a prefix argument uses ``rst-compile-secondary-toolset`` (default
is ``'latex``).

.. note:: 

   In general it is preferred to use a Makefile to automate the
   conversion of many documents or a hierarchy of documents.  The
   functionality presented above is meant to be convenient for use on
   single files.


Other / External Useful Emacs Settings
======================================

This section covers general emacs text-mode settings that are useful
in the context of reStructuredText_ conventions.  These are not
provided by ``rst.el`` but you may find them useful specifically for
reStructuredText_ documents.


Settings for Filling Lists
--------------------------

One problem with the default text-mode settings is that *filling* long
lines in bullet and enumerated lists that do not have an empty line
between them merges them together, e.g.::

     - Bananas;
     - One Apple a day keeps the doctor away, and eating more keeps the pirates at bay;
     - Oranges;

Becomes::

     - Bananas; One Apple a day keeps the doctor away, and eating more
     - keeps the pirates at bay; Oranges;

This is usually not what you want. What you want is this::

     - Bananas;
     - One Apple a day keeps the doctor away, and eating more keeps
       the pirates at bay;
     - Oranges;

The problem is that emacs does not recognize the various consecutive
items as forming paragraph boundaries.  You can fix this easily by
changing the global value of the parapraph boundary detection to
recognize such lists, using the ``rst-set-paragraph-separation``
function::

   (add-hook 'text-mode-hook 'rst-set-paragraph-separation)


``text-mode`` Settings
----------------------

Consult the Emacs manual for more text-mode customizations.  In
particular, you may be interested in setting the following variables,
functions and modes that pertain somewhat to text-mode:

- indent-tabs-mode
- colon-double-space
- auto-fill-mode
- auto-mode-alist
- fill-region


Editing Tables: Emacs table mode
--------------------------------

You may want to check out `Emacs table mode`_ to create an edit
tables, it allows creating ascii tables compatible with
reStructuredText_.

.. _Emacs table mode: http://table.sourceforge.net/


Character Processing
--------------------

Since reStructuredText punts on the issue of character processing,
here are some useful resources for Emacs users in the Unicode world:

* `xmlunicode.el and unichars.el from Norman Walsh
  <http://nwalsh.com/emacs/xmlchars/index.html>`__

* `An essay by Tim Bray, with example code
  <http://www.tbray.org/ongoing/When/200x/2003/09/27/UniEmacs>`__

* For Emacs users on Mac OS X, here are some useful useful additions
  to your .emacs file.

  - To get direct keyboard input of non-ASCII characters (like
    "option-e e" resulting in "é" [eacute]), first enable the option
    key by setting the command key as your meta key::

        (setq mac-command-key-is-meta t) ;; nil for option key

    Next, use one of these lines::

        (set-keyboard-coding-system 'mac-roman)
        (setq mac-keyboard-text-encoding kTextEncodingISOLatin1)

    I prefer the first line, because it enables non-Latin-1 characters
    as well (em-dash, curly quotes, etc.).

  - To enable the display of all characters in the Mac-Roman charset,
    first create a fontset listing the fonts to use for each range of
    characters using charsets that Emacs understands::

      (create-fontset-from-fontset-spec
       "-apple-monaco-medium-r-normal--10-*-*-*-*-*-fontset-monaco,
        ascii:-apple-monaco-medium-r-normal--10-100-75-75-m-100-mac-roman,
        latin-iso8859-1:-apple-monaco-medium-r-normal--10-100-75-75-m-100-mac-roman,
        mule-unicode-0100-24ff:-apple-monaco-medium-r-normal--10-100-75-75-m-100-mac-roman")

    Latin-1 doesn't cover characters like em-dash and curly quotes, so
    "mule-unicode-0100-24ff" is needed.

    Next, use that fontset::

        (set-frame-font "fontset-monaco")

  - To enable cooperation between the system clipboard and the Emacs
    kill ring, add this line::

        (set-clipboard-coding-system 'mac-roman)

  Other useful resources are in `Andrew Choi's Emacs 21 for Mac OS X
  FAQ <http://members.shaw.ca/akochoi-emacs/stories/faq.html>`__.

No matter what platform (or editor) you're using, I recommend the
ProFont__ programmer's font.  It's monospaced, small but readable,
similar characters are visually distinctive (like "I1l|", "0O", "ao",
and ".,:;"), and free.

__ http://www.tobias-jung.de/seekingprofont/


Credits
=======

- The automatic section adjustment and table of contents features were
  written by Martin Blais;
- ``rst-mode`` and its syntax highlighting was implemented by Stefan
  Merten;
- Various other functions were implemented by David Goodger.


Obsolete Files
==============

On 2005-10-30, ``restructuredtext.el``, ``rst-html.el`` and
``rst-mode.el`` were merged to form the new ``rst.el``.  You can
consider the old files obsolete and remove them.


Future Work
===========

Here are some features and ideas that will be worked on in the future,
in those frenzied mornings of excitement over the virtues of the
one-true-way kitchen sink of editors:

- It would be nice to differentiate between text files using
  reStructuredText_ and other general text files.  If we had a
  function to automatically guess whether a .txt file is following the
  reStructuredText_ conventions, we could trigger rst-mode without
  having to hard-code this in every text file, nor forcing the user to
  add a local mode variable at the top of the file.

  We could perform this guessing by searching for a valid decoration
  at the top of the document or searching for reStructuredText_
  directives further on.

- The suggested decorations when adjusting should not have to cycle
  below one below the last section decoration level preceding the
  cursor.  We need to fix that.


.. _Emacs: http://www.gnu.org/software/emacs/emacs.html
.. _reStructuredText: http://docutils.sf.net/rst.html


..
   Local Variables:
   mode: indented-text
   indent-tabs-mode: nil
   sentence-end-double-space: t
   fill-column: 70
   End:
