How to migrate the Coq Reference Manual to Sphinx
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# Install Python3 packages (requires Python 3, python3-pip, python3-setuptools)

  * pip3 install bs4 sphinx sphinx_rtd_theme pexpect antlr4-python3-runtime sphinxcontrib-bibtex

# You may want to do this under a virtualenv, particularly if you end up with issues finding sphinxcontrib.bibtex. http://docs.python-guide.org/en/latest/dev/virtualenvs/

  * pip3 install virtualenv
  * virtualenv coqsphinxing # you may want to use -p to specify the python version
  * source coqsphinxing/bin/activate # activate the virtual environment

# After activating the virtual environment you can run the above pip3 command to install sphinx. You will have to activate the virtual environment before building the docs in your session.

# Add this Elisp code to .emacs, if you're using emacs (recommended):

 (defun sphinx/quote-coq-refman-region (left right &optional beg end count)
   (unless beg
     (if (region-active-p)
         (setq beg (region-beginning) end (region-end))
       (setq beg (point) end nil)))
   (unless count
     (setq count 1))
   (save-excursion
     (goto-char (or end beg))
     (dotimes (_ count) (insert right)))
   (save-excursion
     (goto-char beg)
     (dotimes (_ count) (insert left)))
   (if (and end (characterp left)) ;; Second test handles the ::`` case
       (goto-char (+ (* 2 count) end))
     (goto-char (+ count beg))))

 (defun sphinx/coqtop (beg end)
   (interactive (list (region-beginning) (region-end)))
   (replace-regexp "^Coq < " "      " nil beg end)
   (indent-rigidly beg end -3)
   (goto-char beg)
   (insert ".. coqtop:: all\n\n"))

 (defun sphinx/rst-coq-action ()
   (interactive)
   (pcase (read-char "Command?")
     (?g (sphinx/quote-coq-refman-region ":g:`" "`"))
     (?n (sphinx/quote-coq-refman-region ":n:`" "`"))
     (?t (sphinx/quote-coq-refman-region ":token:`" "`"))
     (?m (sphinx/quote-coq-refman-region ":math:`" "`"))
     (?: (sphinx/quote-coq-refman-region "::`" "`"))
     (?` (sphinx/quote-coq-refman-region "``" "``"))
     (?c (sphinx/coqtop (region-beginning) (region-end)))))

 (global-set-key (kbd "<f12>") #'sphinx/rst-coq-action)

 With this code installed, you can hit "F12" followed by an appropriate key to do quick markup of text
 (this will make more sense once you've started editing the text).

# Fork the Coq repo, if needed:

 https://github.com/coq/coq

# Clone the repo to your work machine

# Add Maxime Dénès's repo as a remote:

 git remote add sphinx https://github.com/maximedenes/coq.git

  (or choose a name other than "sphinx")

 Verify with:

 git remote -v

# Fetch from the remote

 git fetch sphinx

# Checkout the sphinx-doc branch

   git checkout sphinx-doc

  You should pull from the repo from time to time to keep your local copy up-to-date:

   git pull sphinx sphinx-doc

  You may want to create a new branch to do your work in.

# Choose a Reference Manual chapter to work on at

    https://docs.google.com/document/d/1Yo7dV4OI0AY9Di-lsEQ3UTmn5ygGLlhxjym7cTCMCWU

# For each chapter, raw ReStructuredText (the Sphinx format), created by the "html2rest" utility,
   is available in the directory porting/raw-rst/

  Elsewhere, depending on the chapter, there should be an almost-empty template file already created,
   which is in the location where the final version should go

# Manually edit the .rst file, place it in the correct location

  There are small examples in sphinx/porting/, a larger example in language/gallina-extensions.rst

  (N.B.: the migration is a work-in-progress, your suggestions are welcome)

  Find the chapter you're working on from the online manual at https://coq.inria.fr/distrib/current/refman/.
  At the top of the file, after the chapter heading, add:

    :Source: https://coq.inria.fr/distrib/current/refman/the-chapter-file.html
    :Converted by: Your Name

  N.B.: These source and converted-by annotations should help for the migration phase. Later on,
  those annotations will be removed, and contributors will be mentioned in the Coq credits.

  Remove chapter numbers

  Replace section, subsection numbers with reference labels:

    .. _some-reference-label:

  Place the label before the section or subsection, followed by a blank line.

  Note the leading underscore. Use :ref:`some_reference-label` to refer to such a label; note the leading underscore is omitted.
  Many cross-references may be to other chapters. If the required label exists, use it. Otherwise, use a dummy reference of the form
  `TODO-n.n.n-mnemonic` we can fixup later. Example:

    :ref:`TODO-1.3.2-definitions`

  We can grep for those TODOs, and the existing subsection number makes it easy to find in the exisyting manual.

  For the particular case of references to chapters, we can use a
convention for the cross-reference name, so no TODO is needed.

    :ref:`thegallinaspecificationlanguage`

That is, the chapter label is the chapter title, all in lower-case,
with no spaces or punctuation. For chapters with subtitles marked with
a ":", like those for Omega and Nsatz, use just the chapter part
preceding the ":". These labels should already be in the
placeholder .rst files for each chapter.


  You can also label other items, like grammars, with the same syntax. To refer to such labels, not involving a
  section or subsection, use the syntax

    :ref:`Some link text <label-name>`

  Yes, the angle-brackets are needed here!

  For bibliographic references (those in biblio.bib), use :cite:`thecitation`.

  Grammars will get mangled by the translation. Look for "productionlist" in the examples, also see
  http://www.sphinx-doc.org/en/stable/markup/para.html.

  For Coq examples that appear, look at the "coqtop" syntax in porting/tricky-bits.rst. The Sphinx
  script will run coqtop on those examples, and can show the output (or not).

  The file replaces.rst contains replacement definitions for some items that are clumsy to write out otherwise.
  Use

    .. include:: replaces.rst

  to gain access to those definitions in your file (you might need a path prefix). Some especially-important
  replacements are |Cic|, |Coq|, |CoqIDE|, and |Gallina|, which display those names in small-caps. Please use them,
  so that they're rendered consistently.

  Similarly, there are some LaTeX macros in preamble.rst that can be useful.

  Conventions:

    - Keywords and other literal text is double-backquoted (e.g. ``Module``, ``Section``, ``(``, ``,``).

    - Metavariables are single-backquotes (e.g. `term`, `ident`)

    - Use the cmd directive for Vernacular commands, like:

      .. cmd:: Set Printing All.

      Within this directive, prefix metavariables (ident, term) with @:

      .. cmd:: Add Printing Let @ident.

      There's also the "cmdv" directive for variants of a command.

    - Use the "exn" and "warn" directives for errors and warnings:

      .. exn:: Something's not right.
      .. warn:: You shouldn't do that.

    - Use the "example" directive for examples

    - Use the "g" role for inline Gallina, like :g:`fun x => x`

    - Use code blocks for blocks of Gallina. You can use a double-colon at the end of a line::

        your code here

      which prints a single colon, or put the double-colon on a newline.

::

        your other code here

# Making changes to the text

  The goal of the migration is simply to change the storage format from LaTeX to ReStructuredText. The goal is not
  to make any organizational or other substantive changes to the text. If you do notice nits (misspellings, wrong
  verb tense, and so on), please do change them. For example, the programming language that Coq is written in is these days
  called "OCaml", and there are mentions of the older name "Objective Caml" in the reference manual that should be changed.

# Build, view the manual

  In the root directory of your local repo, run "make sphinx". You can view the result in a browser by loading the HTML file
  associated with your chapter, which will be contained in the directory doc/sphinx/_build/html/ beneath the repo root directory.
  Make any changes you need until there are no build warnings and the output is perfect. :-)

# Creating pull requests

  When your changes are done, commit them, push to your fork:

   git commit -m "useful commit message" file
   git push origin sphinx-doc

  (or push to another branch, if you've created one). Then go to your GitHub
  fork and create a pull request against Maxime's sphinx-doc
  branch. If your commit is recent, you should see a link on your
  fork's code page to do that. Otherwise, you may need to go to your
  branch on GitHub to do that.

# Issues/Questions/Suggestions

  As the migration proceeds, if you have technical issues, have a more general question, or want to suggest something, please contact:

    Paul Steckler <steck@stecksoft.com>
    Maxime Dénès <maxime.denes@inria.fr>

# Issues

  Should the stuff in replaces.rst go in preamble.rst?
  In LaTeX, some of the grammars add productions to existing nonterminals, like term ++= ... . How to indicate that?