# minirst.py - minimal reStructuredText parser
#
# Copyright 2009, 2010 Matt Mackall <mpm@selenic.com> 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 http://mercurial.selenic.com/wiki/HelpStyleGuide
when adding support for new constructs.
"""
import re, sys
import util, encoding
from i18n import _
def replace(text, substs):
utext = text.decode(encoding.encoding)
for f, t in substs:
utext = utext.replace(f, t)
return utext.encode(encoding.encoding)
_blockre = re.compile(r"\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()
indent = min((len(l) - len(l.lstrip())) for l in lines)
lines = [l[indent:] for l in lines]
blocks.append(dict(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]
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(r'(-|[0-9A-Za-z]+\.|\(?[0-9A-Za-z]+\)|\|) ')
_optionre = re.compile(r'^(-([a-zA-Z0-9]), )?(--[a-z0-9-]+)'
r'((.*) +)(.*)$')
_fieldre = re.compile(r':(?![: ])([^:]*)(?<! ):[ ]+(.*)')
_definitionre = re.compile(r'[^ ]')
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 idented 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(dict(type=type, lines=[],
indent=blocks[i]['indent']))
items[-1]['lines'].append(line)
blocks[i:i + 1] = items
break
i += 1
return blocks
_fieldwidth = 12
def updatefieldlists(blocks):
"""Find key and maximum key width for field lists."""
i = 0
while i < len(blocks):
if blocks[i]['type'] != 'field':
i += 1
continue
keywidth = 0
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
keywidth = max(keywidth, len(key))
j += 1
for block in blocks[i:j]:
block['keywidth'] = keywidth
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 = containertype not in keep
if prune:
pruned.append(containertype)
# Always delete "..container:: type" block
del blocks[i]
j = i
while j < len(blocks) and blocks[j]['indent'] > indent:
if prune:
del blocks[j]
i -= 1 # adjust outer index
else:
blocks[j]['indent'] -= adjustment
j += 1
i += 1
return blocks, pruned
_sectionre = re.compile(r"""^([-=`:.'"~^_*+#])\1+$""")
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
else:
blocks.insert(i, dict(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
_admonitionre = re.compile(r"\.\. (admonition|attention|caution|danger|"
r"error|hint|important|note|tip|warning)::",
flags=re.IGNORECASE)
def findadmonitions(blocks):
"""
Makes the type of the block an admonition block if
the first line is an admonition directive
"""
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' % (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']]
hang = len(block['lines'][-1]) - len(block['lines'][-1].lstrip())
defindent = indent + hang * ' '
text = ' '.join(map(str.strip, block['lines']))
return '%s\n%s' % (indent + admonition, util.wrap(text, width=width,
initindent=defindent,
hangindent=defindent))
if block['type'] == 'margin':
return ''
if block['type'] == 'literal':
indent += ' '
return indent + ('\n' + indent).join(block['lines'])
if block['type'] == 'section':
underline = encoding.colwidth(block['lines'][0]) * block['underline']
return "%s%s\n%s%s" % (indent, block['lines'][0],indent, underline)
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' % (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
# indention.
block['lines'][0] = block['lines'][0][2:]
else:
m = _bulletre.match(block['lines'][0])
subindent = indent + m.end() * ' '
elif block['type'] == 'field':
keywidth = block['keywidth']
key = block['key']
subindent = indent + _fieldwidth * ' '
if len(key) + 2 > _fieldwidth:
# key too large, use full line width
key = key.ljust(width)
elif keywidth + 2 < _fieldwidth:
# all keys are small, add only two spaces
key = key.ljust(keywidth + 2)
subindent = indent + (keywidth + 2) * ' '
else:
# mixed sizes, use fieldwidth for this one
key = key.ljust(_fieldwidth)
block['lines'][0] = key + block['lines'][0]
elif block['type'] == 'option':
return formatoption(block, width)
text = ' '.join(map(str.strip, block['lines']))
return util.wrap(text, width=width,
initindent=indent,
hangindent=subindent)
def parse(text, indent=0, keep=None):
"""Parse text into a list of blocks"""
pruned = []
blocks = findblocks(text)
for b in blocks:
b['indent'] += indent
blocks = findliteralblocks(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 = addmargins(blocks)
blocks = prunecomments(blocks)
blocks = findadmonitions(blocks)
return blocks, pruned
def formatblocks(blocks, width):
text = '\n'.join(formatblock(b, width) for b in blocks)
return text
def format(text, width, indent=0, keep=None):
"""Parse and format the text according to width."""
blocks, pruned = parse(text, indent, keep or [])
text = '\n'.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 = []
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((b['lines'][0], level, [b]))
else:
if not secs:
# add an initial empty section
secs = [('', 0, [])]
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
if __name__ == "__main__":
from pprint import pprint
def debug(func, *args):
blocks = func(*args)
print "*** after %s:" % func.__name__
pprint(blocks)
print
return blocks
text = sys.stdin.read()
blocks = debug(findblocks, text)
blocks = debug(findliteralblocks, blocks)
blocks, pruned = debug(prunecontainers, blocks, sys.argv[1:])
blocks = debug(inlineliterals, blocks)
blocks = debug(splitparagraphs, blocks)
blocks = debug(updatefieldlists, blocks)
blocks = debug(updateoptionlists, blocks)
blocks = debug(findsections, blocks)
blocks = debug(addmargins, blocks)
blocks = debug(prunecomments, blocks)
blocks = debug(findadmonitions, blocks)
print '\n'.join(formatblock(b, 30) for b in blocks)