srcanamdw/codescanner/pyinstaller/optik/textwrap.py
changeset 1 22878952f6e2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/srcanamdw/codescanner/pyinstaller/optik/textwrap.py	Thu Feb 18 12:29:02 2010 +0530
@@ -0,0 +1,374 @@
+"""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: textwrap.py,v 1.1 2009/02/05 23:03:30 stechong Exp $"
+
+import string, re
+import types
+
+# 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).
+try:
+    True, False
+except NameError:
+    (True, False) = (1, 0)
+
+# For Python 1.5, just ignore unicode (try it as str)
+try:
+    unicode
+except NameError:
+    unicode=str
+
+__all__ = ['TextWrapper', 'wrap', 'fill']
+
+# 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'.
+    """
+
+    whitespace_trans = string.maketrans(_whitespace, ' ' * len(_whitespace))
+
+    unicode_whitespace_trans = {}
+    uspace = ord(unicode(' '))
+    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).
+    try:
+        wordsep_re = re.compile(r'(\s+|'                  # any whitespace
+                                r'[^\s\w]*\w{2,}-(?=\w{2,})|' # hyphenated words
+                                r'(?<=[\w\!\"\'\&\.\,\?])-{2,}(?=\w))')   # em-dash
+    except:
+        # Under python 1.5, the above regular expression does not compile because
+        # of positive look-behind assertions (?<=). This stripped down version
+        # does but it causes some regressions in the testsuite. Better than
+        # nothing...
+        wordsep_re = re.compile(r'(\s+|'                  # any whitespace
+                                r'[^\s\w]*\w{2,}-(?=\w{2,})|' # hyphenated words
+                                r')')   # em-dash
+
+    # 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
+                                 % 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):
+        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
+
+
+    # -- 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 = string.expandtabs(text)
+        if self.replace_whitespace:
+            if isinstance(text, types.StringType):
+                text = string.translate(text, self.whitespace_trans)
+            elif isinstance(text, types.UnicodeType):
+                # This has to be Python 2.0+ (no unicode before), so
+                # use directly string methods (the string module does not
+                # support translate() with dictionary for 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!'
+        """
+        chunks = self.wordsep_re.split(text)
+        chunks = filter(None, 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
+        pat = self.sentence_end_re
+        while i < len(chunks)-1:
+            if chunks[i+1] == " " and pat.search(chunks[i]):
+                chunks[i+1] = "  "
+                i = i+2
+            else:
+                i = i+1
+
+    def _handle_long_word(self, 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.
+        """
+        space_left = max(width - cur_len, 1)
+
+        # 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(chunks[0][0:space_left])
+            chunks[0] = chunks[0][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(chunks.pop(0))
+
+        # 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)
+
+        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 string.strip(chunks[0]) == '' and lines:
+                del chunks[0]
+
+            while chunks:
+                l = len(chunks[0])
+
+                # Can at least squeeze this chunk onto the current line.
+                if cur_len + l <= width:
+                    cur_line.append(chunks.pop(0))
+                    cur_len = 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[0]) > width:
+                self._handle_long_word(chunks, cur_line, cur_len, width)
+
+            # If the last chunk on this line is all whitespace, drop it.
+            if cur_line and string.strip(cur_line[-1]) == '':
+                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 + string.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)
+        indent = self.initial_indent
+        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 string.join(self.wrap(text), "\n")
+
+
+# -- 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.
+    """
+    kwargs["width"] = width
+    w = apply(TextWrapper, (), 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.
+    """
+    kwargs["width"] = width
+    w = apply(TextWrapper, (), kwargs)
+    return w.fill(text)
+
+
+# -- Loosely related functionality -------------------------------------
+
+def dedent(text):
+    """dedent(text : string) -> string
+
+    Remove any whitespace than can be uniformly removed from the left
+    of every line in `text`.
+
+    This can be used e.g. to make triple-quoted strings line up with
+    the left edge of screen/whatever, while still presenting it in the
+    source code in indented form.
+
+    For example:
+
+        def test():
+            # end first line with \ to avoid the empty line!
+            s = '''\
+            hello
+              world
+            '''
+            print repr(s)          # prints '    hello\n      world\n    '
+            print repr(dedent(s))  # prints 'hello\n  world\n'
+    """
+    lines = string.split(string.expandtabs(text), '\n')
+    margin = None
+    for line in lines:
+        content = string.lstrip(line)
+        if not content:
+            continue
+        indent = len(line) - len(content)
+        if margin is None:
+            margin = indent
+        else:
+            margin = min(margin, indent)
+
+    if margin is not None and margin > 0:
+        for i in range(len(lines)):
+            lines[i] = lines[i][margin:]
+
+    return string.join(lines, "\n")