mercurial/formatter.py

help: format command and option list help using RST

This patch changes the function which generates help text about commands and
options to use RST formatting. Tables describing options have been formatted
using RST table markup for some time already, so their appearance does not
change. Command lists, however, change appearance.

To format non-verbose command lists, RST field list markup was chosen, because
it resembles the old format:

<http://docutils.sourceforge.net/docs/user/rst/quickref.html#field-lists>

In the old (hand-coded) format of non-verbose command lists, the left column is
12 characters wide. Our minirst implementation formats field lists with a left
column 14 characters wide, so this patch changes the appearance of help output
correspondingly:

<http://markmail.org/message/krl4cxopsnii7s6z?q=mercurial+reinert+from:%22Olav+Reinert%22&page=2>

The minirst markup most closely resembling the old verbose command lists is
definition lists. But using it would cause a blank line to be inserted between
each command definition, making the output excessively long, and no more
useful than before. To avoid this, I chose to use field lists also for verbose
command help, resulting in output like this example:

 add           add the specified files on the next commit
 annotate, blame
               show changeset information by line for each file
 clone         make a copy of an existing repository
 commit, ci    commit the specified files or all outstanding changes
 diff          diff repository (or selected files)
 export        dump the header and diffs for one or more changesets
 forget        forget the specified files on the next commit
 init          create a new repository in the given directory
 log, history  show revision history of entire repository or files
 merge         merge working directory with another revision
 phase         set or show the current phase name
 pull          pull changes from the specified source
 push          push changes to the specified destination
 qdiff         diff of the current patch and subsequent modifications
 qinit         init a new queue repository (DEPRECATED)
 qnew          create a new patch
 qpop          pop the current patch off the stack
 qpush         push the next patch onto the stack
 qrefresh      update the current patch
 remove, rm    remove the specified files on the next commit
 serve         start stand-alone webserver
 status, st    show changed files in the working directory
 summary, sum  summarize working directory state
 update, up, checkout, co
               update working directory (or switch revisions)

This change is a move towards generating all help text as a list of strings
marked up with RST.

# formatter.py - generic output formatting for mercurial
#
# Copyright 2012 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

class baseformatter(object):
    def __init__(self, ui, topic, opts):
        self._ui = ui
        self._topic = topic
        self._style = opts.get("style")
        self._template = opts.get("template")
        self._item = None
    def __bool__(self):
        '''return False if we're not doing real templating so we can
        skip extra work'''
        return True
    def _showitem(self):
        '''show a formatted item once all data is collected'''
        pass
    def startitem(self):
        '''begin an item in the format list'''
        if self._item is not None:
            self._showitem()
        self._item = {}
    def data(self, **data):
        '''insert data into item that's not shown in default output'''
    def write(self, fields, deftext, *fielddata, **opts):
        '''do default text output while assigning data to item'''
        for k, v in zip(fields.split(), fielddata):
            self._item[k] = v
    def plain(self, text, **opts):
        '''show raw text for non-templated mode'''
        pass
    def end(self):
        '''end output for the formatter'''
        if self._item is not None:
            self._showitem()

class plainformatter(baseformatter):
    '''the default text output scheme'''
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
    def __bool__(self):
        return False
    def startitem(self):
        pass
    def data(self, **data):
        pass
    def write(self, fields, deftext, *fielddata, **opts):
        self._ui.write(deftext % fielddata, **opts)
    def plain(self, text, **opts):
        self._ui.write(text, **opts)
    def end(self):
        pass

class debugformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._ui.write("%s = {\n" % self._topic)
    def _showitem(self):
        self._ui.write("    " + repr(self._item) + ",\n")
    def end(self):
        baseformatter.end(self)
        self._ui.write("}\n")

def formatter(ui, topic, opts):
    if ui.configbool('ui', 'formatdebug'):
        return debugformatter(ui, topic, opts)
    return plainformatter(ui, topic, opts)