mirror of
https://github.com/QB64-Phoenix-Edition/QB64pe.git
synced 2024-09-07 10:40:17 +00:00
425 lines
17 KiB
Python
425 lines
17 KiB
Python
"""Text wrapping and filling.
|
|
"""
|
|
|
|
# Copyright (C) 1999-2001 Gregory P. Ward.
|
|
# Copyright (C) 2002, 2003 Python Software Foundation.
|
|
# Written by Greg Ward <gward@python.net>
|
|
|
|
__revision__ = "$Id$"
|
|
|
|
import string, re
|
|
|
|
try:
|
|
_unicode = unicode
|
|
except NameError:
|
|
# If Python is built without Unicode support, the unicode type
|
|
# will not exist. Fake one.
|
|
class _unicode(object):
|
|
pass
|
|
|
|
# Do the right thing with boolean values for all known Python versions
|
|
# (so this module can be copied to projects that don't depend on Python
|
|
# 2.3, e.g. Optik and Docutils) by uncommenting the block of code below.
|
|
#try:
|
|
# True, False
|
|
#except NameError:
|
|
# (True, False) = (1, 0)
|
|
|
|
__all__ = ['TextWrapper', 'wrap', 'fill', 'dedent']
|
|
|
|
# Hardcode the recognized whitespace characters to the US-ASCII
|
|
# whitespace characters. The main reason for doing this is that in
|
|
# ISO-8859-1, 0xa0 is non-breaking whitespace, so in certain locales
|
|
# that character winds up in string.whitespace. Respecting
|
|
# string.whitespace in those cases would 1) make textwrap treat 0xa0 the
|
|
# same as any other whitespace char, which is clearly wrong (it's a
|
|
# *non-breaking* space), 2) possibly cause problems with Unicode,
|
|
# since 0xa0 is not in range(128).
|
|
_whitespace = '\t\n\x0b\x0c\r '
|
|
|
|
class TextWrapper:
|
|
"""
|
|
Object for wrapping/filling text. The public interface consists of
|
|
the wrap() and fill() methods; the other methods are just there for
|
|
subclasses to override in order to tweak the default behaviour.
|
|
If you want to completely replace the main wrapping algorithm,
|
|
you'll probably have to override _wrap_chunks().
|
|
|
|
Several instance attributes control various aspects of wrapping:
|
|
width (default: 70)
|
|
the maximum width of wrapped lines (unless break_long_words
|
|
is false)
|
|
initial_indent (default: "")
|
|
string that will be prepended to the first line of wrapped
|
|
output. Counts towards the line's width.
|
|
subsequent_indent (default: "")
|
|
string that will be prepended to all lines save the first
|
|
of wrapped output; also counts towards each line's width.
|
|
expand_tabs (default: true)
|
|
Expand tabs in input text to spaces before further processing.
|
|
Each tab will become 1 .. 8 spaces, depending on its position in
|
|
its line. If false, each tab is treated as a single character.
|
|
replace_whitespace (default: true)
|
|
Replace all whitespace characters in the input text by spaces
|
|
after tab expansion. Note that if expand_tabs is false and
|
|
replace_whitespace is true, every tab will be converted to a
|
|
single space!
|
|
fix_sentence_endings (default: false)
|
|
Ensure that sentence-ending punctuation is always followed
|
|
by two spaces. Off by default because the algorithm is
|
|
(unavoidably) imperfect.
|
|
break_long_words (default: true)
|
|
Break words longer than 'width'. If false, those words will not
|
|
be broken, and some lines might be longer than 'width'.
|
|
break_on_hyphens (default: true)
|
|
Allow breaking hyphenated words. If true, wrapping will occur
|
|
preferably on whitespaces and right after hyphens part of
|
|
compound words.
|
|
drop_whitespace (default: true)
|
|
Drop leading and trailing whitespace from lines.
|
|
"""
|
|
|
|
whitespace_trans = string.maketrans(_whitespace, ' ' * len(_whitespace))
|
|
|
|
unicode_whitespace_trans = {}
|
|
uspace = ord(u' ')
|
|
for x in map(ord, _whitespace):
|
|
unicode_whitespace_trans[x] = uspace
|
|
|
|
# This funky little regex is just the trick for splitting
|
|
# text up into word-wrappable chunks. E.g.
|
|
# "Hello there -- you goof-ball, use the -b option!"
|
|
# splits into
|
|
# Hello/ /there/ /--/ /you/ /goof-/ball,/ /use/ /the/ /-b/ /option!
|
|
# (after stripping out empty strings).
|
|
wordsep_re = re.compile(
|
|
r'(\s+|' # any whitespace
|
|
r'[^\s\w]*\w+[^0-9\W]-(?=\w+[^0-9\W])|' # hyphenated words
|
|
r'(?<=[\w\!\"\'\&\.\,\?])-{2,}(?=\w))') # em-dash
|
|
|
|
# This less funky little regex just split on recognized spaces. E.g.
|
|
# "Hello there -- you goof-ball, use the -b option!"
|
|
# splits into
|
|
# Hello/ /there/ /--/ /you/ /goof-ball,/ /use/ /the/ /-b/ /option!/
|
|
wordsep_simple_re = re.compile(r'(\s+)')
|
|
|
|
# XXX this is not locale- or charset-aware -- string.lowercase
|
|
# is US-ASCII only (and therefore English-only)
|
|
sentence_end_re = re.compile(r'[%s]' # lowercase letter
|
|
r'[\.\!\?]' # sentence-ending punct.
|
|
r'[\"\']?' # optional end-of-quote
|
|
r'\Z' # end of chunk
|
|
% string.lowercase)
|
|
|
|
|
|
def __init__(self,
|
|
width=70,
|
|
initial_indent="",
|
|
subsequent_indent="",
|
|
expand_tabs=True,
|
|
replace_whitespace=True,
|
|
fix_sentence_endings=False,
|
|
break_long_words=True,
|
|
drop_whitespace=True,
|
|
break_on_hyphens=True):
|
|
self.width = width
|
|
self.initial_indent = initial_indent
|
|
self.subsequent_indent = subsequent_indent
|
|
self.expand_tabs = expand_tabs
|
|
self.replace_whitespace = replace_whitespace
|
|
self.fix_sentence_endings = fix_sentence_endings
|
|
self.break_long_words = break_long_words
|
|
self.drop_whitespace = drop_whitespace
|
|
self.break_on_hyphens = break_on_hyphens
|
|
|
|
# recompile the regexes for Unicode mode -- done in this clumsy way for
|
|
# backwards compatibility because it's rather common to monkey-patch
|
|
# the TextWrapper class' wordsep_re attribute.
|
|
self.wordsep_re_uni = re.compile(self.wordsep_re.pattern, re.U)
|
|
self.wordsep_simple_re_uni = re.compile(
|
|
self.wordsep_simple_re.pattern, re.U)
|
|
|
|
|
|
# -- Private methods -----------------------------------------------
|
|
# (possibly useful for subclasses to override)
|
|
|
|
def _munge_whitespace(self, text):
|
|
"""_munge_whitespace(text : string) -> string
|
|
|
|
Munge whitespace in text: expand tabs and convert all other
|
|
whitespace characters to spaces. Eg. " foo\tbar\n\nbaz"
|
|
becomes " foo bar baz".
|
|
"""
|
|
if self.expand_tabs:
|
|
text = text.expandtabs()
|
|
if self.replace_whitespace:
|
|
if isinstance(text, str):
|
|
text = text.translate(self.whitespace_trans)
|
|
elif isinstance(text, _unicode):
|
|
text = text.translate(self.unicode_whitespace_trans)
|
|
return text
|
|
|
|
|
|
def _split(self, text):
|
|
"""_split(text : string) -> [string]
|
|
|
|
Split the text to wrap into indivisible chunks. Chunks are
|
|
not quite the same as words; see _wrap_chunks() for full
|
|
details. As an example, the text
|
|
Look, goof-ball -- use the -b option!
|
|
breaks into the following chunks:
|
|
'Look,', ' ', 'goof-', 'ball', ' ', '--', ' ',
|
|
'use', ' ', 'the', ' ', '-b', ' ', 'option!'
|
|
if break_on_hyphens is True, or in:
|
|
'Look,', ' ', 'goof-ball', ' ', '--', ' ',
|
|
'use', ' ', 'the', ' ', '-b', ' ', option!'
|
|
otherwise.
|
|
"""
|
|
if isinstance(text, _unicode):
|
|
if self.break_on_hyphens:
|
|
pat = self.wordsep_re_uni
|
|
else:
|
|
pat = self.wordsep_simple_re_uni
|
|
else:
|
|
if self.break_on_hyphens:
|
|
pat = self.wordsep_re
|
|
else:
|
|
pat = self.wordsep_simple_re
|
|
chunks = pat.split(text)
|
|
chunks = filter(None, chunks) # remove empty chunks
|
|
return chunks
|
|
|
|
def _fix_sentence_endings(self, chunks):
|
|
"""_fix_sentence_endings(chunks : [string])
|
|
|
|
Correct for sentence endings buried in 'chunks'. Eg. when the
|
|
original text contains "... foo.\nBar ...", munge_whitespace()
|
|
and split() will convert that to [..., "foo.", " ", "Bar", ...]
|
|
which has one too few spaces; this method simply changes the one
|
|
space to two.
|
|
"""
|
|
i = 0
|
|
patsearch = self.sentence_end_re.search
|
|
while i < len(chunks)-1:
|
|
if chunks[i+1] == " " and patsearch(chunks[i]):
|
|
chunks[i+1] = " "
|
|
i += 2
|
|
else:
|
|
i += 1
|
|
|
|
def _handle_long_word(self, reversed_chunks, cur_line, cur_len, width):
|
|
"""_handle_long_word(chunks : [string],
|
|
cur_line : [string],
|
|
cur_len : int, width : int)
|
|
|
|
Handle a chunk of text (most likely a word, not whitespace) that
|
|
is too long to fit in any line.
|
|
"""
|
|
# Figure out when indent is larger than the specified width, and make
|
|
# sure at least one character is stripped off on every pass
|
|
if width < 1:
|
|
space_left = 1
|
|
else:
|
|
space_left = width - cur_len
|
|
|
|
# If we're allowed to break long words, then do so: put as much
|
|
# of the next chunk onto the current line as will fit.
|
|
if self.break_long_words:
|
|
cur_line.append(reversed_chunks[-1][:space_left])
|
|
reversed_chunks[-1] = reversed_chunks[-1][space_left:]
|
|
|
|
# Otherwise, we have to preserve the long word intact. Only add
|
|
# it to the current line if there's nothing already there --
|
|
# that minimizes how much we violate the width constraint.
|
|
elif not cur_line:
|
|
cur_line.append(reversed_chunks.pop())
|
|
|
|
# If we're not allowed to break long words, and there's already
|
|
# text on the current line, do nothing. Next time through the
|
|
# main loop of _wrap_chunks(), we'll wind up here again, but
|
|
# cur_len will be zero, so the next line will be entirely
|
|
# devoted to the long word that we can't handle right now.
|
|
|
|
def _wrap_chunks(self, chunks):
|
|
"""_wrap_chunks(chunks : [string]) -> [string]
|
|
|
|
Wrap a sequence of text chunks and return a list of lines of
|
|
length 'self.width' or less. (If 'break_long_words' is false,
|
|
some lines may be longer than this.) Chunks correspond roughly
|
|
to words and the whitespace between them: each chunk is
|
|
indivisible (modulo 'break_long_words'), but a line break can
|
|
come between any two chunks. Chunks should not have internal
|
|
whitespace; ie. a chunk is either all whitespace or a "word".
|
|
Whitespace chunks will be removed from the beginning and end of
|
|
lines, but apart from that whitespace is preserved.
|
|
"""
|
|
lines = []
|
|
if self.width <= 0:
|
|
raise ValueError("invalid width %r (must be > 0)" % self.width)
|
|
|
|
# Arrange in reverse order so items can be efficiently popped
|
|
# from a stack of chucks.
|
|
chunks.reverse()
|
|
|
|
while chunks:
|
|
|
|
# Start the list of chunks that will make up the current line.
|
|
# cur_len is just the length of all the chunks in cur_line.
|
|
cur_line = []
|
|
cur_len = 0
|
|
|
|
# Figure out which static string will prefix this line.
|
|
if lines:
|
|
indent = self.subsequent_indent
|
|
else:
|
|
indent = self.initial_indent
|
|
|
|
# Maximum width for this line.
|
|
width = self.width - len(indent)
|
|
|
|
# First chunk on line is whitespace -- drop it, unless this
|
|
# is the very beginning of the text (ie. no lines started yet).
|
|
if self.drop_whitespace and chunks[-1].strip() == '' and lines:
|
|
del chunks[-1]
|
|
|
|
while chunks:
|
|
l = len(chunks[-1])
|
|
|
|
# Can at least squeeze this chunk onto the current line.
|
|
if cur_len + l <= width:
|
|
cur_line.append(chunks.pop())
|
|
cur_len += l
|
|
|
|
# Nope, this line is full.
|
|
else:
|
|
break
|
|
|
|
# The current line is full, and the next chunk is too big to
|
|
# fit on *any* line (not just this one).
|
|
if chunks and len(chunks[-1]) > width:
|
|
self._handle_long_word(chunks, cur_line, cur_len, width)
|
|
|
|
# If the last chunk on this line is all whitespace, drop it.
|
|
if self.drop_whitespace and cur_line and cur_line[-1].strip() == '':
|
|
del cur_line[-1]
|
|
|
|
# Convert current line back to a string and store it in list
|
|
# of all lines (return value).
|
|
if cur_line:
|
|
lines.append(indent + ''.join(cur_line))
|
|
|
|
return lines
|
|
|
|
|
|
# -- Public interface ----------------------------------------------
|
|
|
|
def wrap(self, text):
|
|
"""wrap(text : string) -> [string]
|
|
|
|
Reformat the single paragraph in 'text' so it fits in lines of
|
|
no more than 'self.width' columns, and return a list of wrapped
|
|
lines. Tabs in 'text' are expanded with string.expandtabs(),
|
|
and all other whitespace characters (including newline) are
|
|
converted to space.
|
|
"""
|
|
text = self._munge_whitespace(text)
|
|
chunks = self._split(text)
|
|
if self.fix_sentence_endings:
|
|
self._fix_sentence_endings(chunks)
|
|
return self._wrap_chunks(chunks)
|
|
|
|
def fill(self, text):
|
|
"""fill(text : string) -> string
|
|
|
|
Reformat the single paragraph in 'text' to fit in lines of no
|
|
more than 'self.width' columns, and return a new string
|
|
containing the entire wrapped paragraph.
|
|
"""
|
|
return "\n".join(self.wrap(text))
|
|
|
|
|
|
# -- Convenience interface ---------------------------------------------
|
|
|
|
def wrap(text, width=70, **kwargs):
|
|
"""Wrap a single paragraph of text, returning a list of wrapped lines.
|
|
|
|
Reformat the single paragraph in 'text' so it fits in lines of no
|
|
more than 'width' columns, and return a list of wrapped lines. By
|
|
default, tabs in 'text' are expanded with string.expandtabs(), and
|
|
all other whitespace characters (including newline) are converted to
|
|
space. See TextWrapper class for available keyword args to customize
|
|
wrapping behaviour.
|
|
"""
|
|
w = TextWrapper(width=width, **kwargs)
|
|
return w.wrap(text)
|
|
|
|
def fill(text, width=70, **kwargs):
|
|
"""Fill a single paragraph of text, returning a new string.
|
|
|
|
Reformat the single paragraph in 'text' to fit in lines of no more
|
|
than 'width' columns, and return a new string containing the entire
|
|
wrapped paragraph. As with wrap(), tabs are expanded and other
|
|
whitespace characters converted to space. See TextWrapper class for
|
|
available keyword args to customize wrapping behaviour.
|
|
"""
|
|
w = TextWrapper(width=width, **kwargs)
|
|
return w.fill(text)
|
|
|
|
|
|
# -- Loosely related functionality -------------------------------------
|
|
|
|
_whitespace_only_re = re.compile('^[ \t]+$', re.MULTILINE)
|
|
_leading_whitespace_re = re.compile('(^[ \t]*)(?:[^ \t\n])', re.MULTILINE)
|
|
|
|
def dedent(text):
|
|
"""Remove any common leading whitespace from every line in `text`.
|
|
|
|
This can be used to make triple-quoted strings line up with the left
|
|
edge of the display, while still presenting them in the source code
|
|
in indented form.
|
|
|
|
Note that tabs and spaces are both treated as whitespace, but they
|
|
are not equal: the lines " hello" and "\thello" are
|
|
considered to have no common leading whitespace. (This behaviour is
|
|
new in Python 2.5; older versions of this module incorrectly
|
|
expanded tabs before searching for common leading whitespace.)
|
|
"""
|
|
# Look for the longest leading string of spaces and tabs common to
|
|
# all lines.
|
|
margin = None
|
|
text = _whitespace_only_re.sub('', text)
|
|
indents = _leading_whitespace_re.findall(text)
|
|
for indent in indents:
|
|
if margin is None:
|
|
margin = indent
|
|
|
|
# Current line more deeply indented than previous winner:
|
|
# no change (previous winner is still on top).
|
|
elif indent.startswith(margin):
|
|
pass
|
|
|
|
# Current line consistent with and no deeper than previous winner:
|
|
# it's the new winner.
|
|
elif margin.startswith(indent):
|
|
margin = indent
|
|
|
|
# Current line and previous winner have no common whitespace:
|
|
# there is no margin.
|
|
else:
|
|
margin = ""
|
|
break
|
|
|
|
# sanity check (testing/debugging only)
|
|
if 0 and margin:
|
|
for line in text.split("\n"):
|
|
assert not line or line.startswith(margin), \
|
|
"line = %r, margin = %r" % (line, margin)
|
|
|
|
if margin:
|
|
text = re.sub(r'(?m)^' + margin, '', text)
|
|
return text
|
|
|
|
if __name__ == "__main__":
|
|
#print dedent("\tfoo\n\tbar")
|
|
#print dedent(" \thello there\n \t how are you?")
|
|
print dedent("Hello there.\n This is indented.")
|