Initial commit of OpenSPARC T2 architecture model.
[OpenSPARC-T2-SAM] / sam-t2 / devtools / v8plus / lib / python2.4 / sre.py
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1#
2# Secret Labs' Regular Expression Engine
3#
4# re-compatible interface for the sre matching engine
5#
6# Copyright (c) 1998-2001 by Secret Labs AB. All rights reserved.
7#
8# This version of the SRE library can be redistributed under CNRI's
9# Python 1.6 license. For any other use, please contact Secret Labs
10# AB (info@pythonware.com).
11#
12# Portions of this engine have been developed in cooperation with
13# CNRI. Hewlett-Packard provided funding for 1.6 integration and
14# other compatibility work.
15#
16
17r"""Support for regular expressions (RE).
18
19This module provides regular expression matching operations similar to
20those found in Perl. It supports both 8-bit and Unicode strings; both
21the pattern and the strings being processed can contain null bytes and
22characters outside the US ASCII range.
23
24Regular expressions can contain both special and ordinary characters.
25Most ordinary characters, like "A", "a", or "0", are the simplest
26regular expressions; they simply match themselves. You can
27concatenate ordinary characters, so last matches the string 'last'.
28
29The special characters are:
30 "." Matches any character except a newline.
31 "^" Matches the start of the string.
32 "$" Matches the end of the string.
33 "*" Matches 0 or more (greedy) repetitions of the preceding RE.
34 Greedy means that it will match as many repetitions as possible.
35 "+" Matches 1 or more (greedy) repetitions of the preceding RE.
36 "?" Matches 0 or 1 (greedy) of the preceding RE.
37 *?,+?,?? Non-greedy versions of the previous three special characters.
38 {m,n} Matches from m to n repetitions of the preceding RE.
39 {m,n}? Non-greedy version of the above.
40 "\\" Either escapes special characters or signals a special sequence.
41 [] Indicates a set of characters.
42 A "^" as the first character indicates a complementing set.
43 "|" A|B, creates an RE that will match either A or B.
44 (...) Matches the RE inside the parentheses.
45 The contents can be retrieved or matched later in the string.
46 (?iLmsux) Set the I, L, M, S, U, or X flag for the RE (see below).
47 (?:...) Non-grouping version of regular parentheses.
48 (?P<name>...) The substring matched by the group is accessible by name.
49 (?P=name) Matches the text matched earlier by the group named name.
50 (?#...) A comment; ignored.
51 (?=...) Matches if ... matches next, but doesn't consume the string.
52 (?!...) Matches if ... doesn't match next.
53
54The special sequences consist of "\\" and a character from the list
55below. If the ordinary character is not on the list, then the
56resulting RE will match the second character.
57 \number Matches the contents of the group of the same number.
58 \A Matches only at the start of the string.
59 \Z Matches only at the end of the string.
60 \b Matches the empty string, but only at the start or end of a word.
61 \B Matches the empty string, but not at the start or end of a word.
62 \d Matches any decimal digit; equivalent to the set [0-9].
63 \D Matches any non-digit character; equivalent to the set [^0-9].
64 \s Matches any whitespace character; equivalent to [ \t\n\r\f\v].
65 \S Matches any non-whitespace character; equiv. to [^ \t\n\r\f\v].
66 \w Matches any alphanumeric character; equivalent to [a-zA-Z0-9_].
67 With LOCALE, it will match the set [0-9_] plus characters defined
68 as letters for the current locale.
69 \W Matches the complement of \w.
70 \\ Matches a literal backslash.
71
72This module exports the following functions:
73 match Match a regular expression pattern to the beginning of a string.
74 search Search a string for the presence of a pattern.
75 sub Substitute occurrences of a pattern found in a string.
76 subn Same as sub, but also return the number of substitutions made.
77 split Split a string by the occurrences of a pattern.
78 findall Find all occurrences of a pattern in a string.
79 compile Compile a pattern into a RegexObject.
80 purge Clear the regular expression cache.
81 escape Backslash all non-alphanumerics in a string.
82
83Some of the functions in this module takes flags as optional parameters:
84 I IGNORECASE Perform case-insensitive matching.
85 L LOCALE Make \w, \W, \b, \B, dependent on the current locale.
86 M MULTILINE "^" matches the beginning of lines as well as the string.
87 "$" matches the end of lines as well as the string.
88 S DOTALL "." matches any character at all, including the newline.
89 X VERBOSE Ignore whitespace and comments for nicer looking RE's.
90 U UNICODE Make \w, \W, \b, \B, dependent on the Unicode locale.
91
92This module also defines an exception 'error'.
93
94"""
95
96import sys
97import sre_compile
98import sre_parse
99
100# public symbols
101__all__ = [ "match", "search", "sub", "subn", "split", "findall",
102 "compile", "purge", "template", "escape", "I", "L", "M", "S", "X",
103 "U", "IGNORECASE", "LOCALE", "MULTILINE", "DOTALL", "VERBOSE",
104 "UNICODE", "error" ]
105
106__version__ = "2.2.1"
107
108# flags
109I = IGNORECASE = sre_compile.SRE_FLAG_IGNORECASE # ignore case
110L = LOCALE = sre_compile.SRE_FLAG_LOCALE # assume current 8-bit locale
111U = UNICODE = sre_compile.SRE_FLAG_UNICODE # assume unicode locale
112M = MULTILINE = sre_compile.SRE_FLAG_MULTILINE # make anchors look for newline
113S = DOTALL = sre_compile.SRE_FLAG_DOTALL # make dot match newline
114X = VERBOSE = sre_compile.SRE_FLAG_VERBOSE # ignore whitespace and comments
115
116# sre extensions (experimental, don't rely on these)
117T = TEMPLATE = sre_compile.SRE_FLAG_TEMPLATE # disable backtracking
118DEBUG = sre_compile.SRE_FLAG_DEBUG # dump pattern after compilation
119
120# sre exception
121error = sre_compile.error
122
123# --------------------------------------------------------------------
124# public interface
125
126def match(pattern, string, flags=0):
127 """Try to apply the pattern at the start of the string, returning
128 a match object, or None if no match was found."""
129 return _compile(pattern, flags).match(string)
130
131def search(pattern, string, flags=0):
132 """Scan through string looking for a match to the pattern, returning
133 a match object, or None if no match was found."""
134 return _compile(pattern, flags).search(string)
135
136def sub(pattern, repl, string, count=0):
137 """Return the string obtained by replacing the leftmost
138 non-overlapping occurrences of the pattern in string by the
139 replacement repl. repl can be either a string or a callable;
140 if a callable, it's passed the match object and must return
141 a replacement string to be used."""
142 return _compile(pattern, 0).sub(repl, string, count)
143
144def subn(pattern, repl, string, count=0):
145 """Return a 2-tuple containing (new_string, number).
146 new_string is the string obtained by replacing the leftmost
147 non-overlapping occurrences of the pattern in the source
148 string by the replacement repl. number is the number of
149 substitutions that were made. repl can be either a string or a
150 callable; if a callable, it's passed the match object and must
151 return a replacement string to be used."""
152 return _compile(pattern, 0).subn(repl, string, count)
153
154def split(pattern, string, maxsplit=0):
155 """Split the source string by the occurrences of the pattern,
156 returning a list containing the resulting substrings."""
157 return _compile(pattern, 0).split(string, maxsplit)
158
159def findall(pattern, string, flags=0):
160 """Return a list of all non-overlapping matches in the string.
161
162 If one or more groups are present in the pattern, return a
163 list of groups; this will be a list of tuples if the pattern
164 has more than one group.
165
166 Empty matches are included in the result."""
167 return _compile(pattern, flags).findall(string)
168
169if sys.hexversion >= 0x02020000:
170 __all__.append("finditer")
171 def finditer(pattern, string, flags=0):
172 """Return an iterator over all non-overlapping matches in the
173 string. For each match, the iterator returns a match object.
174
175 Empty matches are included in the result."""
176 return _compile(pattern, flags).finditer(string)
177
178def compile(pattern, flags=0):
179 "Compile a regular expression pattern, returning a pattern object."
180 return _compile(pattern, flags)
181
182def purge():
183 "Clear the regular expression cache"
184 _cache.clear()
185 _cache_repl.clear()
186
187def template(pattern, flags=0):
188 "Compile a template pattern, returning a pattern object"
189 return _compile(pattern, flags|T)
190
191def escape(pattern):
192 "Escape all non-alphanumeric characters in pattern."
193 s = list(pattern)
194 for i in range(len(pattern)):
195 c = pattern[i]
196 if not ("a" <= c <= "z" or "A" <= c <= "Z" or "0" <= c <= "9"):
197 if c == "\000":
198 s[i] = "\\000"
199 else:
200 s[i] = "\\" + c
201 return pattern[:0].join(s)
202
203# --------------------------------------------------------------------
204# internals
205
206_cache = {}
207_cache_repl = {}
208
209_pattern_type = type(sre_compile.compile("", 0))
210
211_MAXCACHE = 100
212
213def _compile(*key):
214 # internal: compile pattern
215 cachekey = (type(key[0]),) + key
216 p = _cache.get(cachekey)
217 if p is not None:
218 return p
219 pattern, flags = key
220 if isinstance(pattern, _pattern_type):
221 return pattern
222 if not sre_compile.isstring(pattern):
223 raise TypeError, "first argument must be string or compiled pattern"
224 try:
225 p = sre_compile.compile(pattern, flags)
226 except error, v:
227 raise error, v # invalid expression
228 if len(_cache) >= _MAXCACHE:
229 _cache.clear()
230 _cache[cachekey] = p
231 return p
232
233def _compile_repl(*key):
234 # internal: compile replacement pattern
235 p = _cache_repl.get(key)
236 if p is not None:
237 return p
238 repl, pattern = key
239 try:
240 p = sre_parse.parse_template(repl, pattern)
241 except error, v:
242 raise error, v # invalid expression
243 if len(_cache_repl) >= _MAXCACHE:
244 _cache_repl.clear()
245 _cache_repl[key] = p
246 return p
247
248def _expand(pattern, match, template):
249 # internal: match.expand implementation hook
250 template = sre_parse.parse_template(template, pattern)
251 return sre_parse.expand_template(template, match)
252
253def _subx(pattern, template):
254 # internal: pattern.sub/subn implementation helper
255 template = _compile_repl(template, pattern)
256 if not template[0] and len(template[1]) == 1:
257 # literal replacement
258 return template[1][0]
259 def filter(match, template=template):
260 return sre_parse.expand_template(template, match)
261 return filter
262
263# register myself for pickling
264
265import copy_reg
266
267def _pickle(p):
268 return _compile, (p.pattern, p.flags)
269
270copy_reg.pickle(_pattern_type, _pickle, _compile)
271
272# --------------------------------------------------------------------
273# experimental stuff (see python-dev discussions for details)
274
275class Scanner:
276 def __init__(self, lexicon, flags=0):
277 from sre_constants import BRANCH, SUBPATTERN
278 self.lexicon = lexicon
279 # combine phrases into a compound pattern
280 p = []
281 s = sre_parse.Pattern()
282 s.flags = flags
283 for phrase, action in lexicon:
284 p.append(sre_parse.SubPattern(s, [
285 (SUBPATTERN, (len(p)+1, sre_parse.parse(phrase, flags))),
286 ]))
287 p = sre_parse.SubPattern(s, [(BRANCH, (None, p))])
288 s.groups = len(p)
289 self.scanner = sre_compile.compile(p)
290 def scan(self, string):
291 result = []
292 append = result.append
293 match = self.scanner.scanner(string).match
294 i = 0
295 while 1:
296 m = match()
297 if not m:
298 break
299 j = m.end()
300 if i == j:
301 break
302 action = self.lexicon[m.lastindex-1][1]
303 if callable(action):
304 self.match = m
305 action = action(self, m.group())
306 if action is not None:
307 append(action)
308 i = j
309 return result, string[i:]