viewvc-4intranet/lib/PyFontify.py

153 lines
4.2 KiB
Python

"""Module to analyze Python source code; for syntax coloring tools.
Interface:
tags = fontify(pytext, searchfrom, searchto)
The 'pytext' argument is a string containing Python source code.
The (optional) arguments 'searchfrom' and 'searchto' may contain a slice in pytext.
The returned value is a list of tuples, formatted like this:
[('keyword', 0, 6, None), ('keyword', 11, 17, None), ('comment', 23, 53, None), etc. ]
The tuple contents are always like this:
(tag, startindex, endindex, sublist)
tag is one of 'keyword', 'string', 'comment' or 'identifier'
sublist is not used, hence always None.
"""
# Based on FontText.py by Mitchell S. Chapman,
# which was modified by Zachary Roadhouse,
# then un-Tk'd by Just van Rossum.
# Many thanks for regular expression debugging & authoring are due to:
# Tim (the-incredib-ly y'rs) Peters and Cristian Tismer
# So, who owns the copyright? ;-) How about this:
# Copyright 1996-1997:
# Mitchell S. Chapman,
# Zachary Roadhouse,
# Tim Peters,
# Just van Rossum
__version__ = "0.3.1"
import string, re
# First a little helper, since I don't like to repeat things. (Tismer speaking)
def replace(where, what, with):
return string.join(string.split(where, what), with)
# This list of keywords is taken from ref/node13.html of the
# Python 1.3 HTML documentation. ("access" is intentionally omitted.)
keywordsList = [
"del", "from", "lambda", "return",
"and", "elif", "global", "not", "try",
"break", "else", "if", "or", "while",
"class", "except", "import", "pass",
"continue", "finally", "in", "print",
"def", "for", "is", "raise"]
# Build up a regular expression which will match anything
# interesting, including multi-line triple-quoted strings.
commentPat = "#.*"
pat = "q[^\q\n]*\(\\\\[\000-\377][^\q\n]*\)*q"
quotePat = replace(pat, "q", "'") + "\|" + replace(pat, 'q', '"')
# Way to go, Tim!
pat = """
qqq
[^\\q]*
\(
\( \\\\[\000-\377]
\| q
\( \\\\[\000-\377]
\| [^\\q]
\| q
\( \\\\[\000-\377]
\| [^\\q]
\)
\)
\)
[^\\q]*
\)*
qqq
"""
pat = string.join(string.split(pat), '') # get rid of whitespace
tripleQuotePat = replace(pat, "q", "'") + "\|" + replace(pat, 'q', '"')
# Build up a regular expression which matches all and only
# Python keywords. This will let us skip the uninteresting
# identifier references.
# nonKeyPat identifies characters which may legally precede
# a keyword pattern.
nonKeyPat = "\(^\|[^a-zA-Z0-9_.\"']\)"
keyPat = nonKeyPat + "\("
for keyword in keywordsList:
keyPat = keyPat + keyword + "\|"
keyPat = keyPat[:-2] + "\)" + nonKeyPat
matchPat = keyPat + "\|" + commentPat + "\|" + tripleQuotePat + "\|" + quotePat
matchRE = re.compile(matchPat)
idKeyPat = "[ \t]*[A-Za-z_][A-Za-z_0-9.]*" # Ident w. leading whitespace.
idRE = re.compile(idKeyPat)
def fontify(pytext, searchfrom = 0, searchto = None):
if searchto is None:
searchto = len(pytext)
# Cache a few attributes for quicker reference.
search = matchRE.search
group = matchRE.group
idSearch = idRE.search
idGroup = idRE.group
tags = []
tags_append = tags.append
commentTag = 'comment'
stringTag = 'string'
keywordTag = 'keyword'
identifierTag = 'identifier'
start = 0
end = searchfrom
while 1:
start = search(pytext, end)
if start < 0 or start >= searchto:
break # EXIT LOOP
match = group(0)
end = start + len(match)
c = match[0]
if c not in "#'\"":
# Must have matched a keyword.
if start <> searchfrom:
# there's still a redundant char before and after it, strip!
match = match[1:-1]
start = start + 1
else:
# this is the first keyword in the text.
# Only a space at the end.
match = match[:-1]
end = end - 1
tags_append((keywordTag, start, end, None))
# If this was a defining keyword, look ahead to the
# following identifier.
if match in ["def", "class"]:
start = idSearch(pytext, end)
if start == end:
match = idGroup(0)
end = start + len(match)
tags_append((identifierTag, start, end, None))
elif c == "#":
tags_append((commentTag, start, end, None))
else:
tags_append((stringTag, start, end, None))
return tags
def test(path):
f = open(path)
text = f.read()
f.close()
tags = fontify(text)
for tag, start, end, sublist in tags:
print tag, `text[start:end]`