343 lines
12 KiB
Python
343 lines
12 KiB
Python
# minirst.py - minimal reStructuredText parser
|
|
#
|
|
# Copyright 2009 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, incorporated herein by reference.
|
|
|
|
"""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.
|
|
|
|
It only supports a small subset of reStructuredText:
|
|
|
|
- paragraphs
|
|
|
|
- definition lists (must use ' ' to indent definitions)
|
|
|
|
- lists (items must start with '-')
|
|
|
|
- field lists (colons cannot be escaped)
|
|
|
|
- literal blocks
|
|
|
|
- option lists (supports only long options without arguments)
|
|
|
|
- inline markup is not recognized at all.
|
|
"""
|
|
|
|
import re, sys, textwrap
|
|
|
|
|
|
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 = [[]]
|
|
lines = text.splitlines()
|
|
for line in lines:
|
|
if line.strip():
|
|
blocks[-1].append(line)
|
|
elif blocks[-1]:
|
|
blocks.append([])
|
|
if not blocks[-1]:
|
|
del blocks[-1]
|
|
|
|
for i, block in enumerate(blocks):
|
|
indent = min((len(l) - len(l.lstrip())) for l in block)
|
|
blocks[i] = dict(indent=indent, lines=[l[indent:] for l in block])
|
|
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.
|
|
if blocks[i]['lines'][0].startswith('- '):
|
|
indent += 2
|
|
adjustment -= 2
|
|
|
|
# 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
|
|
|
|
|
|
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
|
|
block['lines'][1] == '-' * len(block['lines'][0])):
|
|
block['type'] = 'section'
|
|
return blocks
|
|
|
|
|
|
def findbulletlists(blocks):
|
|
"""Finds bullet lists.
|
|
|
|
The blocks must have a 'type' field, i.e., they should have been
|
|
run through findliteralblocks first.
|
|
"""
|
|
i = 0
|
|
while i < len(blocks):
|
|
# Searching for a paragraph that looks like this:
|
|
#
|
|
# +------+-----------------------+
|
|
# | "- " | list item |
|
|
# +------| (body elements)+ |
|
|
# +-----------------------+
|
|
if (blocks[i]['type'] == 'paragraph' and
|
|
blocks[i]['lines'][0].startswith('- ')):
|
|
items = []
|
|
for line in blocks[i]['lines']:
|
|
if line.startswith('- '):
|
|
items.append(dict(type='bullet', lines=[],
|
|
indent=blocks[i]['indent']))
|
|
line = line[2:]
|
|
items[-1]['lines'].append(line)
|
|
blocks[i:i+1] = items
|
|
i += len(items) - 1
|
|
i += 1
|
|
return blocks
|
|
|
|
|
|
_optionre = re.compile(r'^(--[a-z-]+)((?:[ =][a-zA-Z][\w-]*)? +)(.*)$')
|
|
def findoptionlists(blocks):
|
|
"""Finds option lists.
|
|
|
|
The blocks must have a 'type' field, i.e., they should have been
|
|
run through findliteralblocks first.
|
|
"""
|
|
i = 0
|
|
while i < len(blocks):
|
|
# Searching for a paragraph that looks like this:
|
|
#
|
|
# +----------------------------+-------------+
|
|
# | "--" option " " | description |
|
|
# +-------+--------------------+ |
|
|
# | (body elements)+ |
|
|
# +----------------------------------+
|
|
if (blocks[i]['type'] == 'paragraph' and
|
|
_optionre.match(blocks[i]['lines'][0])):
|
|
options = []
|
|
for line in blocks[i]['lines']:
|
|
m = _optionre.match(line)
|
|
if m:
|
|
option, arg, rest = m.groups()
|
|
width = len(option) + len(arg)
|
|
options.append(dict(type='option', lines=[],
|
|
indent=blocks[i]['indent'],
|
|
width=width))
|
|
options[-1]['lines'].append(line)
|
|
blocks[i:i+1] = options
|
|
i += len(options) - 1
|
|
i += 1
|
|
return blocks
|
|
|
|
|
|
_fieldre = re.compile(r':(?![: ])([^:]*)(?<! ):( +)(.*)')
|
|
def findfieldlists(blocks):
|
|
"""Finds fields lists.
|
|
|
|
The blocks must have a 'type' field, i.e., they should have been
|
|
run through findliteralblocks first.
|
|
"""
|
|
i = 0
|
|
while i < len(blocks):
|
|
# Searching for a paragraph that looks like this:
|
|
#
|
|
#
|
|
# +--------------------+----------------------+
|
|
# | ":" field name ":" | field body |
|
|
# +-------+------------+ |
|
|
# | (body elements)+ |
|
|
# +-----------------------------------+
|
|
if (blocks[i]['type'] == 'paragraph' and
|
|
_fieldre.match(blocks[i]['lines'][0])):
|
|
indent = blocks[i]['indent']
|
|
fields = []
|
|
for line in blocks[i]['lines']:
|
|
m = _fieldre.match(line)
|
|
if m:
|
|
key, spaces, rest = m.groups()
|
|
width = 2 + len(key) + len(spaces)
|
|
fields.append(dict(type='field', lines=[],
|
|
indent=indent, width=width))
|
|
# Turn ":foo: bar" into "foo bar".
|
|
line = '%s %s%s' % (key, spaces, rest)
|
|
fields[-1]['lines'].append(line)
|
|
blocks[i:i+1] = fields
|
|
i += len(fields) - 1
|
|
i += 1
|
|
return blocks
|
|
|
|
|
|
def finddefinitionlists(blocks):
|
|
"""Finds definition lists.
|
|
|
|
The blocks must have a 'type' field, i.e., they should have been
|
|
run through findliteralblocks first.
|
|
"""
|
|
i = 0
|
|
while i < len(blocks):
|
|
# Searching for a paragraph that looks like this:
|
|
#
|
|
# +----------------------------+
|
|
# | term |
|
|
# +--+-------------------------+--+
|
|
# | definition |
|
|
# | (body elements)+ |
|
|
# +----------------------------+
|
|
if (blocks[i]['type'] == 'paragraph' and
|
|
len(blocks[i]['lines']) > 1 and
|
|
not blocks[i]['lines'][0].startswith(' ') and
|
|
blocks[i]['lines'][1].startswith(' ')):
|
|
definitions = []
|
|
for line in blocks[i]['lines']:
|
|
if not line.startswith(' '):
|
|
definitions.append(dict(type='definition', lines=[],
|
|
indent=blocks[i]['indent']))
|
|
definitions[-1]['lines'].append(line)
|
|
definitions[-1]['hang'] = len(line) - len(line.lstrip())
|
|
blocks[i:i+1] = definitions
|
|
i += len(definitions) - 1
|
|
i += 1
|
|
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', 'definition')):
|
|
i += 1
|
|
else:
|
|
blocks.insert(i, dict(lines=[''], indent=0, type='margin'))
|
|
i += 2
|
|
return blocks
|
|
|
|
|
|
def formatblock(block, width):
|
|
"""Format a block according to width."""
|
|
indent = ' ' * block['indent']
|
|
if block['type'] == 'margin':
|
|
return ''
|
|
elif block['type'] == 'literal':
|
|
indent += ' '
|
|
return indent + ('\n' + indent).join(block['lines'])
|
|
elif block['type'] == 'section':
|
|
return indent + ('\n' + indent).join(block['lines'])
|
|
elif block['type'] == 'definition':
|
|
term = indent + block['lines'][0]
|
|
defindent = indent + block['hang'] * ' '
|
|
text = ' '.join(map(str.strip, block['lines'][1:]))
|
|
return "%s\n%s" % (term, textwrap.fill(text, width=width,
|
|
initial_indent=defindent,
|
|
subsequent_indent=defindent))
|
|
else:
|
|
initindent = subindent = indent
|
|
text = ' '.join(map(str.strip, block['lines']))
|
|
if block['type'] == 'bullet':
|
|
initindent = indent + '- '
|
|
subindent = indent + ' '
|
|
elif block['type'] in ('option', 'field'):
|
|
subindent = indent + block['width'] * ' '
|
|
|
|
return textwrap.fill(text, width=width,
|
|
initial_indent=initindent,
|
|
subsequent_indent=subindent)
|
|
|
|
|
|
def format(text, width):
|
|
"""Parse and format the text according to width."""
|
|
blocks = findblocks(text)
|
|
blocks = findliteralblocks(blocks)
|
|
blocks = findsections(blocks)
|
|
blocks = findbulletlists(blocks)
|
|
blocks = findoptionlists(blocks)
|
|
blocks = findfieldlists(blocks)
|
|
blocks = finddefinitionlists(blocks)
|
|
blocks = addmargins(blocks)
|
|
return '\n'.join(formatblock(b, width) for b in blocks)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
from pprint import pprint
|
|
|
|
def debug(func, blocks):
|
|
blocks = func(blocks)
|
|
print "*** after %s:" % func.__name__
|
|
pprint(blocks)
|
|
print
|
|
return blocks
|
|
|
|
text = open(sys.argv[1]).read()
|
|
blocks = debug(findblocks, text)
|
|
blocks = debug(findliteralblocks, blocks)
|
|
blocks = debug(findsections, blocks)
|
|
blocks = debug(findbulletlists, blocks)
|
|
blocks = debug(findoptionlists, blocks)
|
|
blocks = debug(findfieldlists, blocks)
|
|
blocks = debug(finddefinitionlists, blocks)
|
|
blocks = debug(addmargins, blocks)
|
|
print '\n'.join(formatblock(b, 30) for b in blocks)
|