Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 1 | # |
| 2 | # Secret Labs' Regular Expression Engine |
| 3 | # $Id$ |
| 4 | # |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 5 | # convert re-style regular expression to sre pattern |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 6 | # |
| 7 | # Copyright (c) 1998-2000 by Secret Labs AB. All rights reserved. |
| 8 | # |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 9 | # Portions of this engine have been developed in cooperation with |
| 10 | # CNRI. Hewlett-Packard provided funding for 1.6 integration and |
| 11 | # other compatibility work. |
| 12 | # |
| 13 | |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 14 | import string, sys |
| 15 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 16 | import _sre |
| 17 | |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 18 | from sre_constants import * |
| 19 | |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 20 | # FIXME: should be 65535, but the arraymodule is still broken |
| 21 | MAXREPEAT = 32767 |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 22 | |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 23 | SPECIAL_CHARS = ".\\[{()*+?^$|" |
| 24 | REPEAT_CHARS = "*+?{" |
| 25 | |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 26 | DIGITS = string.digits |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 27 | |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 28 | OCTDIGITS = "01234567" |
| 29 | HEXDIGITS = "0123456789abcdefABCDEF" |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 30 | |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 31 | WHITESPACE = string.whitespace |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 32 | |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 33 | ESCAPES = { |
| 34 | "\\a": (LITERAL, chr(7)), |
| 35 | "\\b": (LITERAL, chr(8)), |
| 36 | "\\f": (LITERAL, chr(12)), |
| 37 | "\\n": (LITERAL, chr(10)), |
| 38 | "\\r": (LITERAL, chr(13)), |
| 39 | "\\t": (LITERAL, chr(9)), |
| 40 | "\\v": (LITERAL, chr(11)) |
| 41 | } |
| 42 | |
| 43 | CATEGORIES = { |
| 44 | "\\A": (AT, AT_BEGINNING), # start of string |
| 45 | "\\b": (AT, AT_BOUNDARY), |
| 46 | "\\B": (AT, AT_NON_BOUNDARY), |
| 47 | "\\d": (IN, [(CATEGORY, CATEGORY_DIGIT)]), |
| 48 | "\\D": (IN, [(CATEGORY, CATEGORY_NOT_DIGIT)]), |
| 49 | "\\s": (IN, [(CATEGORY, CATEGORY_SPACE)]), |
| 50 | "\\S": (IN, [(CATEGORY, CATEGORY_NOT_SPACE)]), |
| 51 | "\\w": (IN, [(CATEGORY, CATEGORY_WORD)]), |
| 52 | "\\W": (IN, [(CATEGORY, CATEGORY_NOT_WORD)]), |
| 53 | "\\Z": (AT, AT_END), # end of string |
| 54 | } |
| 55 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 56 | FLAGS = { |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 57 | # standard flags |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 58 | "i": SRE_FLAG_IGNORECASE, |
| 59 | "L": SRE_FLAG_LOCALE, |
| 60 | "m": SRE_FLAG_MULTILINE, |
| 61 | "s": SRE_FLAG_DOTALL, |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 62 | "x": SRE_FLAG_VERBOSE, |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 63 | # extensions |
| 64 | "t": SRE_FLAG_TEMPLATE, |
| 65 | "u": SRE_FLAG_UNICODE, |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 66 | } |
| 67 | |
| 68 | class State: |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 69 | def __init__(self): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 70 | self.flags = 0 |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 71 | self.groups = 1 |
| 72 | self.groupdict = {} |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 73 | def getgroup(self, name=None): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 74 | gid = self.groups |
| 75 | self.groups = gid + 1 |
| 76 | if name: |
| 77 | self.groupdict[name] = gid |
| 78 | return gid |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 79 | |
| 80 | class SubPattern: |
| 81 | # a subpattern, in intermediate form |
| 82 | def __init__(self, pattern, data=None): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 83 | self.pattern = pattern |
| 84 | if not data: |
| 85 | data = [] |
| 86 | self.data = data |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 87 | self.width = None |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 88 | def __repr__(self): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 89 | return repr(self.data) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 90 | def __len__(self): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 91 | return len(self.data) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 92 | def __delitem__(self, index): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 93 | del self.data[index] |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 94 | def __getitem__(self, index): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 95 | return self.data[index] |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 96 | def __setitem__(self, index, code): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 97 | self.data[index] = code |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 98 | def __getslice__(self, start, stop): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 99 | return SubPattern(self.pattern, self.data[start:stop]) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 100 | def insert(self, index, code): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 101 | self.data.insert(index, code) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 102 | def append(self, code): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 103 | self.data.append(code) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 104 | def getwidth(self): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 105 | # determine the width (min, max) for this subpattern |
| 106 | if self.width: |
| 107 | return self.width |
| 108 | lo = hi = 0L |
| 109 | for op, av in self.data: |
| 110 | if op is BRANCH: |
| 111 | l = sys.maxint |
| 112 | h = 0 |
| 113 | for av in av[1]: |
| 114 | i, j = av.getwidth() |
| 115 | l = min(l, i) |
| 116 | h = min(h, j) |
| 117 | lo = lo + i |
| 118 | hi = hi + j |
| 119 | elif op is CALL: |
| 120 | i, j = av.getwidth() |
| 121 | lo = lo + i |
| 122 | hi = hi + j |
| 123 | elif op is SUBPATTERN: |
| 124 | i, j = av[1].getwidth() |
| 125 | lo = lo + i |
| 126 | hi = hi + j |
| 127 | elif op in (MIN_REPEAT, MAX_REPEAT): |
| 128 | i, j = av[2].getwidth() |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 129 | lo = lo + long(i) * av[0] |
| 130 | hi = hi + long(j) * av[1] |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 131 | elif op in (ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY): |
| 132 | lo = lo + 1 |
| 133 | hi = hi + 1 |
| 134 | elif op == SUCCESS: |
| 135 | break |
| 136 | self.width = int(min(lo, sys.maxint)), int(min(hi, sys.maxint)) |
| 137 | return self.width |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 138 | |
| 139 | class Tokenizer: |
| 140 | def __init__(self, string): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 141 | self.index = 0 |
| 142 | self.string = string |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 143 | self.next = self.__next() |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 144 | def __next(self): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 145 | if self.index >= len(self.string): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 146 | return None |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 147 | char = self.string[self.index] |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 148 | if char[0] == "\\": |
| 149 | try: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 150 | c = self.string[self.index + 1] |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 151 | except IndexError: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 152 | raise error, "bogus escape" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 153 | char = char + c |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 154 | self.index = self.index + len(char) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 155 | return char |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 156 | def match(self, char): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 157 | if char == self.next: |
| 158 | self.next = self.__next() |
| 159 | return 1 |
| 160 | return 0 |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 161 | def match_set(self, set): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 162 | if self.next and self.next in set: |
| 163 | self.next = self.__next() |
| 164 | return 1 |
| 165 | return 0 |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 166 | def get(self): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 167 | this = self.next |
| 168 | self.next = self.__next() |
| 169 | return this |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 170 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 171 | def _group(escape, state): |
| 172 | # check if the escape string represents a valid group |
| 173 | try: |
| 174 | group = int(escape[1:]) |
| 175 | if group and group < state.groups: |
| 176 | return group |
| 177 | except ValueError: |
| 178 | pass |
| 179 | return None # not a valid group |
| 180 | |
| 181 | def _class_escape(source, escape): |
| 182 | # handle escape code inside character class |
| 183 | code = ESCAPES.get(escape) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 184 | if code: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 185 | return code |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 186 | code = CATEGORIES.get(escape) |
| 187 | if code: |
| 188 | return code |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 189 | try: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 190 | if escape[1:2] == "x": |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 191 | while source.next and source.next in HEXDIGITS: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 192 | escape = escape + source.get() |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 193 | escape = escape[2:] |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 194 | # FIXME: support unicode characters! |
| 195 | return LITERAL, chr(int(escape[-4:], 16) & 0xff) |
| 196 | elif str(escape[1:2]) in OCTDIGITS: |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 197 | while source.next and source.next in OCTDIGITS: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 198 | escape = escape + source.get() |
| 199 | escape = escape[1:] |
| 200 | # FIXME: support unicode characters! |
| 201 | return LITERAL, chr(int(escape[-6:], 8) & 0xff) |
| 202 | if len(escape) == 2: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 203 | return LITERAL, escape[1] |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 204 | except ValueError: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 205 | pass |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 206 | raise error, "bogus escape: %s" % repr(escape) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 207 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 208 | def _escape(source, escape, state): |
| 209 | # handle escape code in expression |
| 210 | code = CATEGORIES.get(escape) |
| 211 | if code: |
| 212 | return code |
| 213 | code = ESCAPES.get(escape) |
| 214 | if code: |
| 215 | return code |
| 216 | try: |
| 217 | if escape[1:2] == "x": |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 218 | while source.next and source.next in HEXDIGITS: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 219 | escape = escape + source.get() |
| 220 | escape = escape[2:] |
| 221 | # FIXME: support unicode characters! |
| 222 | return LITERAL, chr(int(escape[-4:], 16) & 0xff) |
| 223 | elif str(escape[1:2]) in DIGITS: |
| 224 | while 1: |
| 225 | group = _group(escape, state) |
| 226 | if group: |
| 227 | if (not source.next or |
| 228 | not _group(escape + source.next, state)): |
| 229 | return GROUP, group |
| 230 | escape = escape + source.get() |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 231 | elif source.next and source.next in OCTDIGITS: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 232 | escape = escape + source.get() |
| 233 | else: |
| 234 | break |
| 235 | escape = escape[1:] |
| 236 | # FIXME: support unicode characters! |
| 237 | return LITERAL, chr(int(escape[-6:], 8) & 0xff) |
| 238 | if len(escape) == 2: |
| 239 | return LITERAL, escape[1] |
| 240 | except ValueError: |
| 241 | pass |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 242 | raise error, "bogus escape: %s" % repr(escape) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 243 | |
| 244 | |
| 245 | def _branch(pattern, items): |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 246 | |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 247 | # form a branch operator from a set of items |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 248 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 249 | subpattern = SubPattern(pattern) |
| 250 | |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 251 | # check if all items share a common prefix |
| 252 | while 1: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 253 | prefix = None |
| 254 | for item in items: |
| 255 | if not item: |
| 256 | break |
| 257 | if prefix is None: |
| 258 | prefix = item[0] |
| 259 | elif item[0] != prefix: |
| 260 | break |
| 261 | else: |
| 262 | # all subitems start with a common "prefix". |
| 263 | # move it out of the branch |
| 264 | for item in items: |
| 265 | del item[0] |
| 266 | subpattern.append(prefix) |
| 267 | continue # check next one |
| 268 | break |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 269 | |
| 270 | # check if the branch can be replaced by a character set |
| 271 | for item in items: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 272 | if len(item) != 1 or item[0][0] != LITERAL: |
| 273 | break |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 274 | else: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 275 | # we can store this as a character set instead of a |
| 276 | # branch (FIXME: use a range if possible) |
| 277 | set = [] |
| 278 | for item in items: |
| 279 | set.append(item[0]) |
| 280 | subpattern.append((IN, set)) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 281 | return subpattern |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 282 | |
| 283 | subpattern.append((BRANCH, (None, items))) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 284 | return subpattern |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 285 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 286 | def _parse(source, state, flags=0): |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 287 | |
| 288 | # parse regular expression pattern into an operator list. |
| 289 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 290 | subpattern = SubPattern(state) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 291 | |
| 292 | while 1: |
| 293 | |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 294 | if source.next in ("|", ")"): |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 295 | break # end of subpattern |
| 296 | this = source.get() |
| 297 | if this is None: |
| 298 | break # end of pattern |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 299 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 300 | if state.flags & SRE_FLAG_VERBOSE: |
| 301 | # skip whitespace and comments |
| 302 | if this in WHITESPACE: |
| 303 | continue |
| 304 | if this == "#": |
| 305 | while 1: |
| 306 | this = source.get() |
| 307 | if this in (None, "\n"): |
| 308 | break |
| 309 | continue |
| 310 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 311 | if this and this[0] not in SPECIAL_CHARS: |
| 312 | subpattern.append((LITERAL, this)) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 313 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 314 | elif this == "[": |
| 315 | # character set |
| 316 | set = [] |
| 317 | ## if source.match(":"): |
| 318 | ## pass # handle character classes |
| 319 | if source.match("^"): |
| 320 | set.append((NEGATE, None)) |
| 321 | # check remaining characters |
| 322 | start = set[:] |
| 323 | while 1: |
| 324 | this = source.get() |
| 325 | if this == "]" and set != start: |
| 326 | break |
| 327 | elif this and this[0] == "\\": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 328 | code1 = _class_escape(source, this) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 329 | elif this: |
| 330 | code1 = LITERAL, this |
| 331 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 332 | raise error, "unexpected end of regular expression" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 333 | if source.match("-"): |
| 334 | # potential range |
| 335 | this = source.get() |
| 336 | if this == "]": |
| 337 | set.append(code1) |
| 338 | set.append((LITERAL, "-")) |
| 339 | break |
| 340 | else: |
| 341 | if this[0] == "\\": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 342 | code2 = _class_escape(source, this) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 343 | else: |
| 344 | code2 = LITERAL, this |
| 345 | if code1[0] != LITERAL or code2[0] != LITERAL: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 346 | raise error, "illegal range" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 347 | if len(code1[1]) != 1 or len(code2[1]) != 1: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 348 | raise error, "illegal range" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 349 | set.append((RANGE, (code1[1], code2[1]))) |
| 350 | else: |
| 351 | if code1[0] is IN: |
| 352 | code1 = code1[1][0] |
| 353 | set.append(code1) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 354 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 355 | # FIXME: <fl> move set optimization to compiler! |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 356 | if len(set)==1 and set[0][0] is LITERAL: |
| 357 | subpattern.append(set[0]) # optimization |
| 358 | elif len(set)==2 and set[0][0] is NEGATE and set[1][0] is LITERAL: |
| 359 | subpattern.append((NOT_LITERAL, set[1][1])) # optimization |
| 360 | else: |
| 361 | # FIXME: <fl> add charmap optimization |
| 362 | subpattern.append((IN, set)) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 363 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 364 | elif this and this[0] in REPEAT_CHARS: |
| 365 | # repeat previous item |
| 366 | if this == "?": |
| 367 | min, max = 0, 1 |
| 368 | elif this == "*": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 369 | min, max = 0, MAXREPEAT |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 370 | elif this == "+": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 371 | min, max = 1, MAXREPEAT |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 372 | elif this == "{": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 373 | min, max = 0, MAXREPEAT |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 374 | lo = hi = "" |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 375 | while source.next and source.next in DIGITS: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 376 | lo = lo + source.get() |
| 377 | if source.match(","): |
Fredrik Lundh | 6c68dc7 | 2000-06-29 10:34:56 +0000 | [diff] [blame] | 378 | while source.next and source.next in DIGITS: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 379 | hi = hi + source.get() |
| 380 | else: |
| 381 | hi = lo |
| 382 | if not source.match("}"): |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 383 | raise error, "bogus range" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 384 | if lo: |
| 385 | min = int(lo) |
| 386 | if hi: |
| 387 | max = int(hi) |
| 388 | # FIXME: <fl> check that hi >= lo! |
| 389 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 390 | raise error, "not supported" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 391 | # figure out which item to repeat |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 392 | if subpattern: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 393 | item = subpattern[-1:] |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 394 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 395 | raise error, "nothing to repeat" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 396 | if source.match("?"): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 397 | subpattern[-1] = (MIN_REPEAT, (min, max, item)) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 398 | else: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 399 | subpattern[-1] = (MAX_REPEAT, (min, max, item)) |
| 400 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 401 | elif this == ".": |
| 402 | subpattern.append((ANY, None)) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 403 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 404 | elif this == "(": |
| 405 | group = 1 |
| 406 | name = None |
| 407 | if source.match("?"): |
| 408 | group = 0 |
| 409 | # options |
| 410 | if source.match("P"): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 411 | # python extensions |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 412 | if source.match("<"): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 413 | # named group: skip forward to end of name |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 414 | name = "" |
| 415 | while 1: |
| 416 | char = source.get() |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 417 | if char is None: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 418 | raise error, "unterminated name" |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 419 | if char == ">": |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 420 | break |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 421 | # FIXME: check for valid character |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 422 | name = name + char |
| 423 | group = 1 |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 424 | elif source.match("="): |
| 425 | # named backreference |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 426 | raise error, "not yet implemented" |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 427 | else: |
| 428 | char = source.get() |
| 429 | if char is None: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 430 | raise error, "unexpected end of pattern" |
| 431 | raise error, "unknown specifier: ?P%s" % char |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 432 | elif source.match(":"): |
| 433 | # non-capturing group |
| 434 | group = 2 |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 435 | elif source.match("#"): |
| 436 | # comment |
| 437 | while 1: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 438 | if source.next is None or source.next == ")": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 439 | break |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 440 | source.get() |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 441 | else: |
| 442 | # flags |
| 443 | while FLAGS.has_key(source.next): |
| 444 | state.flags = state.flags | FLAGS[source.get()] |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 445 | if group: |
| 446 | # parse group contents |
| 447 | b = [] |
| 448 | if group == 2: |
| 449 | # anonymous group |
| 450 | group = None |
| 451 | else: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 452 | group = state.getgroup(name) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 453 | while 1: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 454 | p = _parse(source, state, flags) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 455 | if source.match(")"): |
| 456 | if b: |
| 457 | b.append(p) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 458 | p = _branch(state, b) |
| 459 | subpattern.append((SUBPATTERN, (group, p))) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 460 | break |
| 461 | elif source.match("|"): |
| 462 | b.append(p) |
| 463 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 464 | raise error, "group not properly closed" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 465 | else: |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 466 | while 1: |
| 467 | char = source.get() |
| 468 | if char is None or char == ")": |
| 469 | break |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 470 | raise error, "unknown extension" |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 471 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 472 | elif this == "^": |
| 473 | subpattern.append((AT, AT_BEGINNING)) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 474 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 475 | elif this == "$": |
| 476 | subpattern.append((AT, AT_END)) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 477 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 478 | elif this and this[0] == "\\": |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 479 | code = _escape(source, this, state) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 480 | subpattern.append(code) |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 481 | |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 482 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 483 | raise error, "parser error" |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 484 | |
| 485 | return subpattern |
| 486 | |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 487 | def parse(pattern, flags=0): |
| 488 | # parse 're' pattern into list of (opcode, argument) tuples |
| 489 | source = Tokenizer(pattern) |
| 490 | state = State() |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 491 | b = [] |
| 492 | while 1: |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 493 | p = _parse(source, state, flags) |
| 494 | tail = source.get() |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 495 | if tail == "|": |
| 496 | b.append(p) |
| 497 | elif tail == ")": |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 498 | raise error, "unbalanced parenthesis" |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 499 | elif tail is None: |
| 500 | if b: |
| 501 | b.append(p) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 502 | p = _branch(state, b) |
Guido van Rossum | b81e70e | 2000-04-10 17:10:48 +0000 | [diff] [blame] | 503 | break |
| 504 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 505 | raise error, "bogus characters at end of regular expression" |
Guido van Rossum | 7627c0d | 2000-03-31 14:58:54 +0000 | [diff] [blame] | 506 | return p |
| 507 | |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 508 | def parse_template(source, pattern): |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 509 | # parse 're' replacement string into list of literals and |
| 510 | # group references |
| 511 | s = Tokenizer(source) |
| 512 | p = [] |
| 513 | a = p.append |
| 514 | while 1: |
| 515 | this = s.get() |
| 516 | if this is None: |
| 517 | break # end of replacement string |
| 518 | if this and this[0] == "\\": |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 519 | if this == "\\g": |
| 520 | name = "" |
| 521 | if s.match("<"): |
| 522 | while 1: |
| 523 | char = s.get() |
| 524 | if char is None: |
| 525 | raise error, "unterminated index" |
| 526 | if char == ">": |
| 527 | break |
| 528 | # FIXME: check for valid character |
| 529 | name = name + char |
| 530 | if not name: |
| 531 | raise error, "bad index" |
| 532 | try: |
| 533 | index = int(name) |
| 534 | except ValueError: |
| 535 | try: |
| 536 | index = pattern.groupindex[name] |
| 537 | except KeyError: |
| 538 | raise IndexError, "unknown index" |
| 539 | a((MARK, index)) |
| 540 | elif len(this) > 1 and this[1] in DIGITS: |
| 541 | while s.next in DIGITS: |
| 542 | this = this + s.get() |
| 543 | a((MARK, int(this[1:]))) |
| 544 | else: |
| 545 | try: |
| 546 | a(ESCAPES[this]) |
| 547 | except KeyError: |
| 548 | for char in this: |
| 549 | a((LITERAL, char)) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 550 | else: |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 551 | a((LITERAL, this)) |
Andrew M. Kuchling | 815d5b9 | 2000-06-09 14:08:07 +0000 | [diff] [blame] | 552 | return p |
| 553 | |
Fredrik Lundh | 436c3d5 | 2000-06-29 08:58:44 +0000 | [diff] [blame] | 554 | def expand_template(template, match): |
| 555 | # FIXME: <fl> this is sooooo slow. drop in the slicelist |
| 556 | # code instead |
| 557 | p = [] |
| 558 | a = p.append |
| 559 | for c, s in template: |
| 560 | if c is LITERAL: |
| 561 | a(s) |
| 562 | elif c is MARK: |
| 563 | s = match.group(s) |
| 564 | if s is None: |
| 565 | raise error, "empty group" |
| 566 | a(s) |
| 567 | return match.string[:0].join(p) |