doc/runrst

tests: add tests and document expectations from visit_children_set in rust

The tests this patch are adding have the form of formal spec in
invariants::visit_children_set::holds,
and then a series of checks that all examples must satisfy this
formal spec.

I tried to make the spec consistent with how this function is used
and how it was originally conceived. This is in conflict with how it's
documented in Rust. Some of the implementations also fail to implement
this spec, which leads to bugs, in particular when complicated patterns
are used with `hg status`.

#!/usr/bin/env python3
#
# runrst - register custom roles and run correct writer
#
# Copyright 2010 Olivia Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""usage: %s WRITER args...

where WRITER is the name of a Docutils writer such as 'html' or 'manpage'
"""


import sys

try:
    import docutils.core as core
    import docutils.nodes as nodes
    import docutils.utils as utils
    import docutils.parsers.rst.roles as roles
except ImportError:
    sys.stderr.write(
        "abort: couldn't generate documentation: docutils "
        "module is missing\n"
    )
    sys.stderr.write(
        "please install python-docutils or see "
        "http://docutils.sourceforge.net/\n"
    )
    sys.exit(-1)


def role_hg(name, rawtext, text, lineno, inliner, options=None, content=None):
    text = "hg " + utils.unescape(text)
    linktext = nodes.literal(rawtext, text)
    parts = text.split()
    cmd, args = parts[1], parts[2:]
    refuri = "hg.1.html#%s" % cmd
    if cmd == 'help' and args:
        if args[0] == 'config':
            # :hg:`help config`
            refuri = "hgrc.5.html"
        elif args[0].startswith('config.'):
            # :hg:`help config.SECTION...`
            refuri = "hgrc.5.html#%s" % args[0].split('.', 2)[1]
        elif len(args) >= 2 and args[0] == '-c':
            # :hg:`help -c COMMAND ...` is equivalent to :hg:`COMMAND`
            # (mainly for :hg:`help -c config`)
            refuri = "hg.1.html#%s" % args[1]
        else:
            refuri = "hg.1.html#%s" % args[0]
    node = nodes.reference(rawtext, '', linktext, refuri=refuri)
    return [node], []


roles.register_local_role("hg", role_hg)

if __name__ == "__main__":
    if len(sys.argv) < 2:
        sys.stderr.write(__doc__ % sys.argv[0])
        sys.exit(1)

    writer = sys.argv[1]
    del sys.argv[1]

    core.publish_cmdline(writer_name=writer)