view mercurial/minirst.py @ 31765:264baeef3588

show: new extension for displaying various repository data

Currently, Mercurial has a number of commands to show information. And,
there are features coming down the pipe that will introduce more
commands for showing information.

Currently, when introducing a new class of data or a view that we
wish to expose to the user, the strategy is to introduce a new command
or overload an existing command, sometimes both. For example, there is
a desire to formalize the wip/smartlog/underway/mine functionality that
many have devised. There is also a desire to introduce a "topics"
concept. Others would like views of "the current stack." In the
current model, we'd need a new command for wip/smartlog/etc (that
behaves a lot like a pre-defined alias of `hg log`). For topics,
we'd likely overload `hg topic[s]` to both display and manipulate
topics.

Adding new commands for every pre-defined query doesn't scale well
and pollutes `hg help`. Overloading commands to perform read-only and
write operations is arguably an UX anti-pattern: while having all
functionality for a given concept in one command is nice, having a
single command doing multiple discrete operations is not. Furthermore,
a user may be surprised that a command they thought was read-only
actually changes something.

We discussed this at the Mercurial 4.0 Sprint in Paris and decided that
having a single command where we could hang pre-defined views of
various data would be a good idea. Having such a command would:

* Help prevent an explosion of new query-related commands
* Create a clear separation between read and write operations
  (mitigates footguns)
* Avoids overloading the meaning of commands that manipulate data
  (bookmark, tag, branch, etc) (while we can't take away the
  existing behavior for BC reasons, we now won't introduce this
  behavior on new commands)
* Allows users to discover informational views more easily by
  aggregating them in a single location
* Lowers the barrier to creating the new views (since the barrier
  to creating a top-level command is relatively high)

So, this commit introduces the `hg show` command via the "show"
extension. This command accepts a positional argument of the
"view" to show. New views can be registered with a decorator. To
prove it works, we implement the "bookmarks" view, which shows a
table of bookmarks and their associated nodes.

We introduce a new style to hold everything used by `hg show`.

For our initial bookmarks view, the output varies from `hg bookmarks`:

* Padding is performed in the template itself as opposed to Python
* Revision integers are not shown
* shortest() is used to display a 5 character node by default (as
  opposed to static 12 characters)

I chose to implement the "bookmarks" view first because it is simple
and shouldn't invite too much bikeshedding that detracts from the
evaluation of `hg show` itself. But there is an important point
to consider: we now have 2 ways to show a list of bookmarks. I'm not
a fan of introducing multiple ways to do very similar things. So it
might be worth discussing how we wish to tackle this issue for
bookmarks, tags, branches, MQ series, etc.

I also made the choice of explicitly declaring the default show
template not part of the standard BC guarantees. History has shown
that we make mistakes and poor choices with output formatting but
can't fix these mistakes later because random tools are parsing
output and we don't want to break these tools. Optimizing for human
consumption is one of my goals for `hg show`. So, by not covering
the formatting as part of BC, the barrier to future change is much
lower and humans benefit.

There are some improvements that can be made to formatting. For
example, we don't yet use label() in the templates. We obviously
want this for color. But I'm not sure if we should reuse the existing
log.* labels or invent new ones. I figure we can punt that to a
follow-up.

At the aforementioned Sprint, we discussed and discarded various
alternatives to `hg show`.

We considered making `hg log <view>` perform this behavior. The main
reason we can't do this is because a positional argument to `hg log`
can be a file path and if there is a conflict between a path name and
a view name, behavior is ambiguous. We could have introduced
`hg log --view` or similar, but we felt that required too much typing
(we don't want to require a command flag to show a view) and wasn't
very discoverable. Furthermore, `hg log` is optimized for showing
changelog data and there are things that `hg display` could display
that aren't changelog centric.

There were concerns about using "show" as the command name.

Some users already have a "show" alias that is similar to `hg export`.

There were also concerns that Git users adapted to `git show` would
be confused by `hg show`'s different behavior. The main difference
here is `git show` prints an `hg export` like view of the current
commit by default and `hg show` requires an argument. `git show`
can also display any Git object. `git show` does not support
displaying more complex views: just single objects. If we
implemented `hg show <hash>` or `hg show <identifier>`, `hg show`
would be a superset of `git show`. Although, I'm hesitant to do that
at this time because I view `hg show` as a higher-level querying
command and there are namespace collisions between valid identifiers
and registered views.

There is also a prefix collision with `hg showconfig`, which is an
alias of `hg config`.

We also considered `hg view`, but that is already used by the "hgk"
extension.

`hg display` was also proposed at one point. It has a prefix collision
with `hg diff`. General consensus was "show" or "view" are the best
verbs. And since "view" was taken, "show" was chosen.

There are a number of inline TODOs in this patch. Some of these
represent decisions yet to be made. Others represent features
requiring non-trivial complexity. Rather than bloat the patch or
invite additional bikeshedding, I figured I'd document future
enhancements via TODO so we can get a minimal implmentation landed.
Something is better than nothing.

# minirst.py - minimal reStructuredText parser
#
# Copyright 2009, 2010 Matt 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.

"""simplified reStructuredText parser.

This parser knows just enough about reStructuredText to parse the
Mercurial docstrings.

It cheats in a major way: nested blocks are not really nested. They
are just indented blocks that look like they are nested. This relies
on the user to keep the right indentation for the blocks.

Remember to update https://mercurial-scm.org/wiki/HelpStyleGuide
when adding support for new constructs.
"""

from __future__ import absolute_import

import cgi
import re

from .i18n import _
from . import (
    encoding,
    pycompat,
    util,
)

def section(s):
    return "%s\n%s\n\n" % (s, "\"" * encoding.colwidth(s))

def subsection(s):
    return "%s\n%s\n\n" % (s, '=' * encoding.colwidth(s))

def subsubsection(s):
    return "%s\n%s\n\n" % (s, "-" * encoding.colwidth(s))

def subsubsubsection(s):
    return "%s\n%s\n\n" % (s, "." * encoding.colwidth(s))

def replace(text, substs):
    '''
    Apply a list of (find, replace) pairs to a text.

    >>> replace("foo bar", [('f', 'F'), ('b', 'B')])
    'Foo Bar'
    >>> encoding.encoding = 'latin1'
    >>> replace('\\x81\\\\', [('\\\\', '/')])
    '\\x81/'
    >>> encoding.encoding = 'shiftjis'
    >>> replace('\\x81\\\\', [('\\\\', '/')])
    '\\x81\\\\'
    '''

    # some character encodings (cp932 for Japanese, at least) use
    # ASCII characters other than control/alphabet/digit as a part of
    # multi-bytes characters, so direct replacing with such characters
    # on strings in local encoding causes invalid byte sequences.
    utext = text.decode(pycompat.sysstr(encoding.encoding))
    for f, t in substs:
        utext = utext.replace(f.decode("ascii"), t.decode("ascii"))
    return utext.encode(pycompat.sysstr(encoding.encoding))

_blockre = re.compile(br"\n(?:\s*\n)+")

def findblocks(text):
    """Find continuous blocks of lines in text.

    Returns a list of dictionaries representing the blocks. Each block
    has an 'indent' field and a 'lines' field.
    """
    blocks = []
    for b in _blockre.split(text.lstrip('\n').rstrip()):
        lines = b.splitlines()
        if lines:
            indent = min((len(l) - len(l.lstrip())) for l in lines)
            lines = [l[indent:] for l in lines]
            blocks.append({'indent': indent, 'lines': lines})
    return blocks

def findliteralblocks(blocks):
    """Finds literal blocks and adds a 'type' field to the blocks.

    Literal blocks are given the type 'literal', all other blocks are
    given type the 'paragraph'.
    """
    i = 0
    while i < len(blocks):
        # Searching for a block that looks like this:
        #
        # +------------------------------+
        # | paragraph                    |
        # | (ends with "::")             |
        # +------------------------------+
        #    +---------------------------+
        #    | indented literal block    |
        #    +---------------------------+
        blocks[i]['type'] = 'paragraph'
        if blocks[i]['lines'][-1].endswith('::') and i + 1 < len(blocks):
            indent = blocks[i]['indent']
            adjustment = blocks[i + 1]['indent'] - indent

            if blocks[i]['lines'] == ['::']:
                # Expanded form: remove block
                del blocks[i]
                i -= 1
            elif blocks[i]['lines'][-1].endswith(' ::'):
                # Partially minimized form: remove space and both
                # colons.
                blocks[i]['lines'][-1] = blocks[i]['lines'][-1][:-3]
            elif len(blocks[i]['lines']) == 1 and \
                 blocks[i]['lines'][0].lstrip(' ').startswith('.. ') and \
                 blocks[i]['lines'][0].find(' ', 3) == -1:
                # directive on its own line, not a literal block
                i += 1
                continue
            else:
                # Fully minimized form: remove just one colon.
                blocks[i]['lines'][-1] = blocks[i]['lines'][-1][:-1]

            # List items are formatted with a hanging indent. We must
            # correct for this here while we still have the original
            # information on the indentation of the subsequent literal
            # blocks available.
            m = _bulletre.match(blocks[i]['lines'][0])
            if m:
                indent += m.end()
                adjustment -= m.end()

            # Mark the following indented blocks.
            while i + 1 < len(blocks) and blocks[i + 1]['indent'] > indent:
                blocks[i + 1]['type'] = 'literal'
                blocks[i + 1]['indent'] -= adjustment
                i += 1
        i += 1
    return blocks

_bulletre = re.compile(br'(\*|-|[0-9A-Za-z]+\.|\(?[0-9A-Za-z]+\)|\|) ')
_optionre = re.compile(br'^(-([a-zA-Z0-9]), )?(--[a-z0-9-]+)'
                       br'((.*)  +)(.*)$')
_fieldre = re.compile(br':(?![: ])([^:]*)(?<! ):[ ]+(.*)')
_definitionre = re.compile(br'[^ ]')
_tablere = re.compile(br'(=+\s+)*=+')

def splitparagraphs(blocks):
    """Split paragraphs into lists."""
    # Tuples with (list type, item regexp, single line items?). Order
    # matters: definition lists has the least specific regexp and must
    # come last.
    listtypes = [('bullet', _bulletre, True),
                 ('option', _optionre, True),
                 ('field', _fieldre, True),
                 ('definition', _definitionre, False)]

    def match(lines, i, itemre, singleline):
        """Does itemre match an item at line i?

        A list item can be followed by an indented line or another list
        item (but only if singleline is True).
        """
        line1 = lines[i]
        line2 = i + 1 < len(lines) and lines[i + 1] or ''
        if not itemre.match(line1):
            return False
        if singleline:
            return line2 == '' or line2[0] == ' ' or itemre.match(line2)
        else:
            return line2.startswith(' ')

    i = 0
    while i < len(blocks):
        if blocks[i]['type'] == 'paragraph':
            lines = blocks[i]['lines']
            for type, itemre, singleline in listtypes:
                if match(lines, 0, itemre, singleline):
                    items = []
                    for j, line in enumerate(lines):
                        if match(lines, j, itemre, singleline):
                            items.append({'type': type, 'lines': [],
                                          'indent': blocks[i]['indent']})
                        items[-1]['lines'].append(line)
                    blocks[i:i + 1] = items
                    break
        i += 1
    return blocks

_fieldwidth = 14

def updatefieldlists(blocks):
    """Find key for field lists."""
    i = 0
    while i < len(blocks):
        if blocks[i]['type'] != 'field':
            i += 1
            continue

        j = i
        while j < len(blocks) and blocks[j]['type'] == 'field':
            m = _fieldre.match(blocks[j]['lines'][0])
            key, rest = m.groups()
            blocks[j]['lines'][0] = rest
            blocks[j]['key'] = key
            j += 1

        i = j + 1

    return blocks

def updateoptionlists(blocks):
    i = 0
    while i < len(blocks):
        if blocks[i]['type'] != 'option':
            i += 1
            continue

        optstrwidth = 0
        j = i
        while j < len(blocks) and blocks[j]['type'] == 'option':
            m = _optionre.match(blocks[j]['lines'][0])

            shortoption = m.group(2)
            group3 = m.group(3)
            longoption = group3[2:].strip()
            desc = m.group(6).strip()
            longoptionarg = m.group(5).strip()
            blocks[j]['lines'][0] = desc

            noshortop = ''
            if not shortoption:
                noshortop = '   '

            opt = "%s%s" %   (shortoption and "-%s " % shortoption or '',
                            ("%s--%s %s") % (noshortop, longoption,
                                             longoptionarg))
            opt = opt.rstrip()
            blocks[j]['optstr'] = opt
            optstrwidth = max(optstrwidth, encoding.colwidth(opt))
            j += 1

        for block in blocks[i:j]:
            block['optstrwidth'] = optstrwidth
        i = j + 1
    return blocks

def prunecontainers(blocks, keep):
    """Prune unwanted containers.

    The blocks must have a 'type' field, i.e., they should have been
    run through findliteralblocks first.
    """
    pruned = []
    i = 0
    while i + 1 < len(blocks):
        # Searching for a block that looks like this:
        #
        # +-------+---------------------------+
        # | ".. container ::" type            |
        # +---+                               |
        #     | blocks                        |
        #     +-------------------------------+
        if (blocks[i]['type'] == 'paragraph' and
            blocks[i]['lines'][0].startswith('.. container::')):
            indent = blocks[i]['indent']
            adjustment = blocks[i + 1]['indent'] - indent
            containertype = blocks[i]['lines'][0][15:]
            prune = True
            for c in keep:
                if c in containertype.split('.'):
                    prune = False
            if prune:
                pruned.append(containertype)

            # Always delete "..container:: type" block
            del blocks[i]
            j = i
            i -= 1
            while j < len(blocks) and blocks[j]['indent'] > indent:
                if prune:
                    del blocks[j]
                else:
                    blocks[j]['indent'] -= adjustment
                    j += 1
        i += 1
    return blocks, pruned

_sectionre = re.compile(br"""^([-=`:.'"~^_*+#])\1+$""")

def findtables(blocks):
    '''Find simple tables

       Only simple one-line table elements are supported
    '''

    for block in blocks:
        # Searching for a block that looks like this:
        #
        # === ==== ===
        #  A    B   C
        # === ==== ===  <- optional
        #  1    2   3
        #  x    y   z
        # === ==== ===
        if (block['type'] == 'paragraph' and
            len(block['lines']) > 2 and
            _tablere.match(block['lines'][0]) and
            block['lines'][0] == block['lines'][-1]):
            block['type'] = 'table'
            block['header'] = False
            div = block['lines'][0]

            # column markers are ASCII so we can calculate column
            # position in bytes
            columns = [x for x in xrange(len(div))
                       if div[x] == '=' and (x == 0 or div[x - 1] == ' ')]
            rows = []
            for l in block['lines'][1:-1]:
                if l == div:
                    block['header'] = True
                    continue
                row = []
                # we measure columns not in bytes or characters but in
                # colwidth which makes things tricky
                pos = columns[0] # leading whitespace is bytes
                for n, start in enumerate(columns):
                    if n + 1 < len(columns):
                        width = columns[n + 1] - start
                        v = encoding.getcols(l, pos, width) # gather columns
                        pos += len(v) # calculate byte position of end
                        row.append(v.strip())
                    else:
                        row.append(l[pos:].strip())
                rows.append(row)

            block['table'] = rows

    return blocks

def findsections(blocks):
    """Finds sections.

    The blocks must have a 'type' field, i.e., they should have been
    run through findliteralblocks first.
    """
    for block in blocks:
        # Searching for a block that looks like this:
        #
        # +------------------------------+
        # | Section title                |
        # | -------------                |
        # +------------------------------+
        if (block['type'] == 'paragraph' and
            len(block['lines']) == 2 and
            encoding.colwidth(block['lines'][0]) == len(block['lines'][1]) and
            _sectionre.match(block['lines'][1])):
            block['underline'] = block['lines'][1][0]
            block['type'] = 'section'
            del block['lines'][1]
    return blocks

def inlineliterals(blocks):
    substs = [('``', '"')]
    for b in blocks:
        if b['type'] in ('paragraph', 'section'):
            b['lines'] = [replace(l, substs) for l in b['lines']]
    return blocks

def hgrole(blocks):
    substs = [(':hg:`', "'hg "), ('`', "'")]
    for b in blocks:
        if b['type'] in ('paragraph', 'section'):
            # Turn :hg:`command` into "hg command". This also works
            # when there is a line break in the command and relies on
            # the fact that we have no stray back-quotes in the input
            # (run the blocks through inlineliterals first).
            b['lines'] = [replace(l, substs) for l in b['lines']]
    return blocks

def addmargins(blocks):
    """Adds empty blocks for vertical spacing.

    This groups bullets, options, and definitions together with no vertical
    space between them, and adds an empty block between all other blocks.
    """
    i = 1
    while i < len(blocks):
        if (blocks[i]['type'] == blocks[i - 1]['type'] and
            blocks[i]['type'] in ('bullet', 'option', 'field')):
            i += 1
        elif not blocks[i - 1]['lines']:
            # no lines in previous block, do not separate
            i += 1
        else:
            blocks.insert(i, {'lines': [''], 'indent': 0, 'type': 'margin'})
            i += 2
    return blocks

def prunecomments(blocks):
    """Remove comments."""
    i = 0
    while i < len(blocks):
        b = blocks[i]
        if b['type'] == 'paragraph' and (b['lines'][0].startswith('.. ') or
                                         b['lines'] == ['..']):
            del blocks[i]
            if i < len(blocks) and blocks[i]['type'] == 'margin':
                del blocks[i]
        else:
            i += 1
    return blocks


def findadmonitions(blocks, admonitions=None):
    """
    Makes the type of the block an admonition block if
    the first line is an admonition directive
    """
    admonitions = admonitions or _admonitiontitles.keys()

    admonitionre = re.compile(br'\.\. (%s)::' % '|'.join(sorted(admonitions)),
                              flags=re.IGNORECASE)

    i = 0
    while i < len(blocks):
        m = admonitionre.match(blocks[i]['lines'][0])
        if m:
            blocks[i]['type'] = 'admonition'
            admonitiontitle = blocks[i]['lines'][0][3:m.end() - 2].lower()

            firstline = blocks[i]['lines'][0][m.end() + 1:]
            if firstline:
                blocks[i]['lines'].insert(1, '   ' + firstline)

            blocks[i]['admonitiontitle'] = admonitiontitle
            del blocks[i]['lines'][0]
        i = i + 1
    return blocks

_admonitiontitles = {
    'attention': _('Attention:'),
    'caution': _('Caution:'),
    'danger': _('!Danger!'),
    'error': _('Error:'),
    'hint': _('Hint:'),
    'important': _('Important:'),
    'note': _('Note:'),
    'tip': _('Tip:'),
    'warning': _('Warning!'),
}

def formatoption(block, width):
    desc = ' '.join(map(str.strip, block['lines']))
    colwidth = encoding.colwidth(block['optstr'])
    usablewidth = width - 1
    hanging = block['optstrwidth']
    initindent = '%s%s  ' % (block['optstr'], ' ' * ((hanging - colwidth)))
    hangindent = ' ' * (encoding.colwidth(initindent) + 1)
    return ' %s\n' % (util.wrap(desc, usablewidth,
                                           initindent=initindent,
                                           hangindent=hangindent))

def formatblock(block, width):
    """Format a block according to width."""
    if width <= 0:
        width = 78
    indent = ' ' * block['indent']
    if block['type'] == 'admonition':
        admonition = _admonitiontitles[block['admonitiontitle']]
        if not block['lines']:
            return indent + admonition + '\n'
        hang = len(block['lines'][-1]) - len(block['lines'][-1].lstrip())

        defindent = indent + hang * ' '
        text = ' '.join(map(str.strip, block['lines']))
        return '%s\n%s\n' % (indent + admonition,
                             util.wrap(text, width=width,
                                       initindent=defindent,
                                       hangindent=defindent))
    if block['type'] == 'margin':
        return '\n'
    if block['type'] == 'literal':
        indent += '  '
        return indent + ('\n' + indent).join(block['lines']) + '\n'
    if block['type'] == 'section':
        underline = encoding.colwidth(block['lines'][0]) * block['underline']
        return "%s%s\n%s%s\n" % (indent, block['lines'][0],indent, underline)
    if block['type'] == 'table':
        table = block['table']
        # compute column widths
        widths = [max([encoding.colwidth(e) for e in c]) for c in zip(*table)]
        text = ''
        span = sum(widths) + len(widths) - 1
        indent = ' ' * block['indent']
        hang = ' ' * (len(indent) + span - widths[-1])

        for row in table:
            l = []
            for w, v in zip(widths, row):
                pad = ' ' * (w - encoding.colwidth(v))
                l.append(v + pad)
            l = ' '.join(l)
            l = util.wrap(l, width=width, initindent=indent, hangindent=hang)
            if not text and block['header']:
                text = l + '\n' + indent + '-' * (min(width, span)) + '\n'
            else:
                text += l + "\n"
        return text
    if block['type'] == 'definition':
        term = indent + block['lines'][0]
        hang = len(block['lines'][-1]) - len(block['lines'][-1].lstrip())
        defindent = indent + hang * ' '
        text = ' '.join(map(str.strip, block['lines'][1:]))
        return '%s\n%s\n' % (term, util.wrap(text, width=width,
                                             initindent=defindent,
                                             hangindent=defindent))
    subindent = indent
    if block['type'] == 'bullet':
        if block['lines'][0].startswith('| '):
            # Remove bullet for line blocks and add no extra
            # indentation.
            block['lines'][0] = block['lines'][0][2:]
        else:
            m = _bulletre.match(block['lines'][0])
            subindent = indent + m.end() * ' '
    elif block['type'] == 'field':
        key = block['key']
        subindent = indent + _fieldwidth * ' '
        if len(key) + 2 > _fieldwidth:
            # key too large, use full line width
            key = key.ljust(width)
        else:
            # key fits within field width
            key = key.ljust(_fieldwidth)
        block['lines'][0] = key + block['lines'][0]
    elif block['type'] == 'option':
        return formatoption(block, width)

    text = ' '.join(map(bytes.strip, block['lines']))
    return util.wrap(text, width=width,
                     initindent=indent,
                     hangindent=subindent) + '\n'

def formathtml(blocks):
    """Format RST blocks as HTML"""

    out = []
    headernest = ''
    listnest = []

    def escape(s):
        return cgi.escape(s, True)

    def openlist(start, level):
        if not listnest or listnest[-1][0] != start:
            listnest.append((start, level))
            out.append('<%s>\n' % start)

    blocks = [b for b in blocks if b['type'] != 'margin']

    for pos, b in enumerate(blocks):
        btype = b['type']
        level = b['indent']
        lines = b['lines']

        if btype == 'admonition':
            admonition = escape(_admonitiontitles[b['admonitiontitle']])
            text = escape(' '.join(map(str.strip, lines)))
            out.append('<p>\n<b>%s</b> %s\n</p>\n' % (admonition, text))
        elif btype == 'paragraph':
            out.append('<p>\n%s\n</p>\n' % escape('\n'.join(lines)))
        elif btype == 'margin':
            pass
        elif btype == 'literal':
            out.append('<pre>\n%s\n</pre>\n' % escape('\n'.join(lines)))
        elif btype == 'section':
            i = b['underline']
            if i not in headernest:
                headernest += i
            level = headernest.index(i) + 1
            out.append('<h%d>%s</h%d>\n' % (level, escape(lines[0]), level))
        elif btype == 'table':
            table = b['table']
            out.append('<table>\n')
            for row in table:
                out.append('<tr>')
                for v in row:
                    out.append('<td>')
                    out.append(escape(v))
                    out.append('</td>')
                    out.append('\n')
                out.pop()
                out.append('</tr>\n')
            out.append('</table>\n')
        elif btype == 'definition':
            openlist('dl', level)
            term = escape(lines[0])
            text = escape(' '.join(map(str.strip, lines[1:])))
            out.append(' <dt>%s\n <dd>%s\n' % (term, text))
        elif btype == 'bullet':
            bullet, head = lines[0].split(' ', 1)
            if bullet in ('*', '-'):
                openlist('ul', level)
            else:
                openlist('ol', level)
            out.append(' <li> %s\n' % escape(' '.join([head] + lines[1:])))
        elif btype == 'field':
            openlist('dl', level)
            key = escape(b['key'])
            text = escape(' '.join(map(str.strip, lines)))
            out.append(' <dt>%s\n <dd>%s\n' % (key, text))
        elif btype == 'option':
            openlist('dl', level)
            opt = escape(b['optstr'])
            desc = escape(' '.join(map(str.strip, lines)))
            out.append(' <dt>%s\n <dd>%s\n' % (opt, desc))

        # close lists if indent level of next block is lower
        if listnest:
            start, level = listnest[-1]
            if pos == len(blocks) - 1:
                out.append('</%s>\n' % start)
                listnest.pop()
            else:
                nb = blocks[pos + 1]
                ni = nb['indent']
                if (ni < level or
                    (ni == level and
                     nb['type'] not in 'definition bullet field option')):
                    out.append('</%s>\n' % start)
                    listnest.pop()

    return ''.join(out)

def parse(text, indent=0, keep=None, admonitions=None):
    """Parse text into a list of blocks"""
    pruned = []
    blocks = findblocks(text)
    for b in blocks:
        b['indent'] += indent
    blocks = findliteralblocks(blocks)
    blocks = findtables(blocks)
    blocks, pruned = prunecontainers(blocks, keep or [])
    blocks = findsections(blocks)
    blocks = inlineliterals(blocks)
    blocks = hgrole(blocks)
    blocks = splitparagraphs(blocks)
    blocks = updatefieldlists(blocks)
    blocks = updateoptionlists(blocks)
    blocks = findadmonitions(blocks, admonitions=admonitions)
    blocks = addmargins(blocks)
    blocks = prunecomments(blocks)
    return blocks, pruned

def formatblocks(blocks, width):
    text = ''.join(formatblock(b, width) for b in blocks)
    return text

def format(text, width=80, indent=0, keep=None, style='plain', section=None):
    """Parse and format the text according to width."""
    blocks, pruned = parse(text, indent, keep or [])
    parents = []
    if section:
        sections = getsections(blocks)
        blocks = []
        i = 0
        lastparents = []
        synthetic = []
        collapse = True
        while i < len(sections):
            name, nest, b = sections[i]
            del parents[nest:]
            parents.append(i)
            if name == section:
                if lastparents != parents:
                    llen = len(lastparents)
                    plen = len(parents)
                    if llen and llen != plen:
                        collapse = False
                    s = []
                    for j in xrange(3, plen - 1):
                        parent = parents[j]
                        if (j >= llen or
                            lastparents[j] != parent):
                            s.append(len(blocks))
                            sec = sections[parent][2]
                            blocks.append(sec[0])
                            blocks.append(sec[-1])
                    if s:
                        synthetic.append(s)

                lastparents = parents[:]
                blocks.extend(b)

                ## Also show all subnested sections
                while i + 1 < len(sections) and sections[i + 1][1] > nest:
                    i += 1
                    blocks.extend(sections[i][2])
            i += 1
        if collapse:
            synthetic.reverse()
            for s in synthetic:
                path = [blocks[syn]['lines'][0] for syn in s]
                real = s[-1] + 2
                realline = blocks[real]['lines']
                realline[0] = ('"%s"' %
                               '.'.join(path + [realline[0]]).replace('"', ''))
                del blocks[s[0]:real]

    if style == 'html':
        text = formathtml(blocks)
    else:
        text = ''.join(formatblock(b, width) for b in blocks)
    if keep is None:
        return text
    else:
        return text, pruned

def getsections(blocks):
    '''return a list of (section name, nesting level, blocks) tuples'''
    nest = ""
    level = 0
    secs = []

    def getname(b):
        if b['type'] == 'field':
            x = b['key']
        else:
            x = b['lines'][0]
        x = encoding.lower(x).strip('"')
        if '(' in x:
            x = x.split('(')[0]
        return x

    for b in blocks:
        if b['type'] == 'section':
            i = b['underline']
            if i not in nest:
                nest += i
            level = nest.index(i) + 1
            nest = nest[:level]
            secs.append((getname(b), level, [b]))
        elif b['type'] in ('definition', 'field'):
            i = ' '
            if i not in nest:
                nest += i
            level = nest.index(i) + 1
            nest = nest[:level]
            for i in range(1, len(secs) + 1):
                sec = secs[-i]
                if sec[1] < level:
                    break
                siblings = [a for a in sec[2] if a['type'] == 'definition']
                if siblings:
                    siblingindent = siblings[-1]['indent']
                    indent = b['indent']
                    if siblingindent < indent:
                        level += 1
                        break
                    elif siblingindent == indent:
                        level = sec[1]
                        break
            secs.append((getname(b), level, [b]))
        else:
            if not secs:
                # add an initial empty section
                secs = [('', 0, [])]
            if b['type'] != 'margin':
                pointer = 1
                bindent = b['indent']
                while pointer < len(secs):
                    section = secs[-pointer][2][0]
                    if section['type'] != 'margin':
                        sindent = section['indent']
                        if len(section['lines']) > 1:
                            sindent += len(section['lines'][1]) - \
                              len(section['lines'][1].lstrip(' '))
                        if bindent >= sindent:
                            break
                    pointer += 1
                if pointer > 1:
                    blevel = secs[-pointer][1]
                    if section['type'] != b['type']:
                        blevel += 1
                    secs.append(('', blevel, []))
            secs[-1][2].append(b)
    return secs

def decorateblocks(blocks, width):
    '''generate a list of (section name, line text) pairs for search'''
    lines = []
    for s in getsections(blocks):
        section = s[0]
        text = formatblocks(s[2], width)
        lines.append([(section, l) for l in text.splitlines(True)])
    return lines

def maketable(data, indent=0, header=False):
    '''Generate an RST table for the given table data as a list of lines'''

    widths = [max(encoding.colwidth(e) for e in c) for c in zip(*data)]
    indent = ' ' * indent
    div = indent + ' '.join('=' * w for w in widths) + '\n'

    out = [div]
    for row in data:
        l = []
        for w, v in zip(widths, row):
            if '\n' in v:
                # only remove line breaks and indentation, long lines are
                # handled by the next tool
                v = ' '.join(e.lstrip() for e in v.split('\n'))
            pad = ' ' * (w - encoding.colwidth(v))
            l.append(v + pad)
        out.append(indent + ' '.join(l) + "\n")
    if header and len(data) > 1:
        out.insert(2, div)
    out.append(div)
    return out