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| 1 # ----------------------------------------------------------------------------- |
| 2 # ply: lex.py |
| 3 # |
| 4 # Copyright (C) 2001-2016 |
| 5 # David M. Beazley (Dabeaz LLC) |
| 6 # All rights reserved. |
| 7 # |
| 8 # Redistribution and use in source and binary forms, with or without |
| 9 # modification, are permitted provided that the following conditions are |
| 10 # met: |
| 11 # |
| 12 # * Redistributions of source code must retain the above copyright notice, |
| 13 # this list of conditions and the following disclaimer. |
| 14 # * Redistributions in binary form must reproduce the above copyright notice, |
| 15 # this list of conditions and the following disclaimer in the documentation |
| 16 # and/or other materials provided with the distribution. |
| 17 # * Neither the name of the David Beazley or Dabeaz LLC may be used to |
| 18 # endorse or promote products derived from this software without |
| 19 # specific prior written permission. |
| 20 # |
| 21 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 22 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 23 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 24 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 25 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 26 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 27 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 28 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 29 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 30 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 31 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 32 # ----------------------------------------------------------------------------- |
| 33 |
| 34 __version__ = '3.9' |
| 35 __tabversion__ = '3.8' |
| 36 |
| 37 import re |
| 38 import sys |
| 39 import types |
| 40 import copy |
| 41 import os |
| 42 import inspect |
| 43 |
| 44 # This tuple contains known string types |
| 45 try: |
| 46 # Python 2.6 |
| 47 StringTypes = (types.StringType, types.UnicodeType) |
| 48 except AttributeError: |
| 49 # Python 3.0 |
| 50 StringTypes = (str, bytes) |
| 51 |
| 52 # This regular expression is used to match valid token names |
| 53 _is_identifier = re.compile(r'^[a-zA-Z0-9_]+$') |
| 54 |
| 55 # Exception thrown when invalid token encountered and no default error |
| 56 # handler is defined. |
| 57 class LexError(Exception): |
| 58 def __init__(self, message, s): |
| 59 self.args = (message,) |
| 60 self.text = s |
| 61 |
| 62 |
| 63 # Token class. This class is used to represent the tokens produced. |
| 64 class LexToken(object): |
| 65 def __str__(self): |
| 66 return 'LexToken(%s,%r,%d,%d)' % (self.type, self.value, self.lineno, se
lf.lexpos) |
| 67 |
| 68 def __repr__(self): |
| 69 return str(self) |
| 70 |
| 71 |
| 72 # This object is a stand-in for a logging object created by the |
| 73 # logging module. |
| 74 |
| 75 class PlyLogger(object): |
| 76 def __init__(self, f): |
| 77 self.f = f |
| 78 |
| 79 def critical(self, msg, *args, **kwargs): |
| 80 self.f.write((msg % args) + '\n') |
| 81 |
| 82 def warning(self, msg, *args, **kwargs): |
| 83 self.f.write('WARNING: ' + (msg % args) + '\n') |
| 84 |
| 85 def error(self, msg, *args, **kwargs): |
| 86 self.f.write('ERROR: ' + (msg % args) + '\n') |
| 87 |
| 88 info = critical |
| 89 debug = critical |
| 90 |
| 91 |
| 92 # Null logger is used when no output is generated. Does nothing. |
| 93 class NullLogger(object): |
| 94 def __getattribute__(self, name): |
| 95 return self |
| 96 |
| 97 def __call__(self, *args, **kwargs): |
| 98 return self |
| 99 |
| 100 |
| 101 # ----------------------------------------------------------------------------- |
| 102 # === Lexing Engine === |
| 103 # |
| 104 # The following Lexer class implements the lexer runtime. There are only |
| 105 # a few public methods and attributes: |
| 106 # |
| 107 # input() - Store a new string in the lexer |
| 108 # token() - Get the next token |
| 109 # clone() - Clone the lexer |
| 110 # |
| 111 # lineno - Current line number |
| 112 # lexpos - Current position in the input string |
| 113 # ----------------------------------------------------------------------------- |
| 114 |
| 115 class Lexer: |
| 116 def __init__(self): |
| 117 self.lexre = None # Master regular expression. This is a lis
t of |
| 118 # tuples (re, findex) where re is a compil
ed |
| 119 # regular expression and findex is a list |
| 120 # mapping regex group numbers to rules |
| 121 self.lexretext = None # Current regular expression strings |
| 122 self.lexstatere = {} # Dictionary mapping lexer states to maste
r regexs |
| 123 self.lexstateretext = {} # Dictionary mapping lexer states to regex
strings |
| 124 self.lexstaterenames = {} # Dictionary mapping lexer states to symbo
l names |
| 125 self.lexstate = 'INITIAL' # Current lexer state |
| 126 self.lexstatestack = [] # Stack of lexer states |
| 127 self.lexstateinfo = None # State information |
| 128 self.lexstateignore = {} # Dictionary of ignored characters for eac
h state |
| 129 self.lexstateerrorf = {} # Dictionary of error functions for each s
tate |
| 130 self.lexstateeoff = {} # Dictionary of eof functions for each sta
te |
| 131 self.lexreflags = 0 # Optional re compile flags |
| 132 self.lexdata = None # Actual input data (as a string) |
| 133 self.lexpos = 0 # Current position in input text |
| 134 self.lexlen = 0 # Length of the input text |
| 135 self.lexerrorf = None # Error rule (if any) |
| 136 self.lexeoff = None # EOF rule (if any) |
| 137 self.lextokens = None # List of valid tokens |
| 138 self.lexignore = '' # Ignored characters |
| 139 self.lexliterals = '' # Literal characters that can be passed th
rough |
| 140 self.lexmodule = None # Module |
| 141 self.lineno = 1 # Current line number |
| 142 self.lexoptimize = False # Optimized mode |
| 143 |
| 144 def clone(self, object=None): |
| 145 c = copy.copy(self) |
| 146 |
| 147 # If the object parameter has been supplied, it means we are attaching t
he |
| 148 # lexer to a new object. In this case, we have to rebind all methods in |
| 149 # the lexstatere and lexstateerrorf tables. |
| 150 |
| 151 if object: |
| 152 newtab = {} |
| 153 for key, ritem in self.lexstatere.items(): |
| 154 newre = [] |
| 155 for cre, findex in ritem: |
| 156 newfindex = [] |
| 157 for f in findex: |
| 158 if not f or not f[0]: |
| 159 newfindex.append(f) |
| 160 continue |
| 161 newfindex.append((getattr(object, f[0].__name__), f[1])) |
| 162 newre.append((cre, newfindex)) |
| 163 newtab[key] = newre |
| 164 c.lexstatere = newtab |
| 165 c.lexstateerrorf = {} |
| 166 for key, ef in self.lexstateerrorf.items(): |
| 167 c.lexstateerrorf[key] = getattr(object, ef.__name__) |
| 168 c.lexmodule = object |
| 169 return c |
| 170 |
| 171 # ------------------------------------------------------------ |
| 172 # writetab() - Write lexer information to a table file |
| 173 # ------------------------------------------------------------ |
| 174 def writetab(self, lextab, outputdir=''): |
| 175 if isinstance(lextab, types.ModuleType): |
| 176 raise IOError("Won't overwrite existing lextab module") |
| 177 basetabmodule = lextab.split('.')[-1] |
| 178 filename = os.path.join(outputdir, basetabmodule) + '.py' |
| 179 with open(filename, 'w') as tf: |
| 180 tf.write('# %s.py. This file automatically created by PLY (version %
s). Don\'t edit!\n' % (basetabmodule, __version__)) |
| 181 tf.write('_tabversion = %s\n' % repr(__tabversion__)) |
| 182 tf.write('_lextokens = set(%s)\n' % repr(tuple(self.lextokens))) |
| 183 tf.write('_lexreflags = %s\n' % repr(self.lexreflags)) |
| 184 tf.write('_lexliterals = %s\n' % repr(self.lexliterals)) |
| 185 tf.write('_lexstateinfo = %s\n' % repr(self.lexstateinfo)) |
| 186 |
| 187 # Rewrite the lexstatere table, replacing function objects with func
tion names |
| 188 tabre = {} |
| 189 for statename, lre in self.lexstatere.items(): |
| 190 titem = [] |
| 191 for (pat, func), retext, renames in zip(lre, self.lexstateretext
[statename], self.lexstaterenames[statename]): |
| 192 titem.append((retext, _funcs_to_names(func, renames))) |
| 193 tabre[statename] = titem |
| 194 |
| 195 tf.write('_lexstatere = %s\n' % repr(tabre)) |
| 196 tf.write('_lexstateignore = %s\n' % repr(self.lexstateignore)) |
| 197 |
| 198 taberr = {} |
| 199 for statename, ef in self.lexstateerrorf.items(): |
| 200 taberr[statename] = ef.__name__ if ef else None |
| 201 tf.write('_lexstateerrorf = %s\n' % repr(taberr)) |
| 202 |
| 203 tabeof = {} |
| 204 for statename, ef in self.lexstateeoff.items(): |
| 205 tabeof[statename] = ef.__name__ if ef else None |
| 206 tf.write('_lexstateeoff = %s\n' % repr(tabeof)) |
| 207 |
| 208 # ------------------------------------------------------------ |
| 209 # readtab() - Read lexer information from a tab file |
| 210 # ------------------------------------------------------------ |
| 211 def readtab(self, tabfile, fdict): |
| 212 if isinstance(tabfile, types.ModuleType): |
| 213 lextab = tabfile |
| 214 else: |
| 215 exec('import %s' % tabfile) |
| 216 lextab = sys.modules[tabfile] |
| 217 |
| 218 if getattr(lextab, '_tabversion', '0.0') != __tabversion__: |
| 219 raise ImportError('Inconsistent PLY version') |
| 220 |
| 221 self.lextokens = lextab._lextokens |
| 222 self.lexreflags = lextab._lexreflags |
| 223 self.lexliterals = lextab._lexliterals |
| 224 self.lextokens_all = self.lextokens | set(self.lexliterals) |
| 225 self.lexstateinfo = lextab._lexstateinfo |
| 226 self.lexstateignore = lextab._lexstateignore |
| 227 self.lexstatere = {} |
| 228 self.lexstateretext = {} |
| 229 for statename, lre in lextab._lexstatere.items(): |
| 230 titem = [] |
| 231 txtitem = [] |
| 232 for pat, func_name in lre: |
| 233 titem.append((re.compile(pat, lextab._lexreflags | re.VERBOSE),
_names_to_funcs(func_name, fdict))) |
| 234 |
| 235 self.lexstatere[statename] = titem |
| 236 self.lexstateretext[statename] = txtitem |
| 237 |
| 238 self.lexstateerrorf = {} |
| 239 for statename, ef in lextab._lexstateerrorf.items(): |
| 240 self.lexstateerrorf[statename] = fdict[ef] |
| 241 |
| 242 self.lexstateeoff = {} |
| 243 for statename, ef in lextab._lexstateeoff.items(): |
| 244 self.lexstateeoff[statename] = fdict[ef] |
| 245 |
| 246 self.begin('INITIAL') |
| 247 |
| 248 # ------------------------------------------------------------ |
| 249 # input() - Push a new string into the lexer |
| 250 # ------------------------------------------------------------ |
| 251 def input(self, s): |
| 252 # Pull off the first character to see if s looks like a string |
| 253 c = s[:1] |
| 254 if not isinstance(c, StringTypes): |
| 255 raise ValueError('Expected a string') |
| 256 self.lexdata = s |
| 257 self.lexpos = 0 |
| 258 self.lexlen = len(s) |
| 259 |
| 260 # ------------------------------------------------------------ |
| 261 # begin() - Changes the lexing state |
| 262 # ------------------------------------------------------------ |
| 263 def begin(self, state): |
| 264 if state not in self.lexstatere: |
| 265 raise ValueError('Undefined state') |
| 266 self.lexre = self.lexstatere[state] |
| 267 self.lexretext = self.lexstateretext[state] |
| 268 self.lexignore = self.lexstateignore.get(state, '') |
| 269 self.lexerrorf = self.lexstateerrorf.get(state, None) |
| 270 self.lexeoff = self.lexstateeoff.get(state, None) |
| 271 self.lexstate = state |
| 272 |
| 273 # ------------------------------------------------------------ |
| 274 # push_state() - Changes the lexing state and saves old on stack |
| 275 # ------------------------------------------------------------ |
| 276 def push_state(self, state): |
| 277 self.lexstatestack.append(self.lexstate) |
| 278 self.begin(state) |
| 279 |
| 280 # ------------------------------------------------------------ |
| 281 # pop_state() - Restores the previous state |
| 282 # ------------------------------------------------------------ |
| 283 def pop_state(self): |
| 284 self.begin(self.lexstatestack.pop()) |
| 285 |
| 286 # ------------------------------------------------------------ |
| 287 # current_state() - Returns the current lexing state |
| 288 # ------------------------------------------------------------ |
| 289 def current_state(self): |
| 290 return self.lexstate |
| 291 |
| 292 # ------------------------------------------------------------ |
| 293 # skip() - Skip ahead n characters |
| 294 # ------------------------------------------------------------ |
| 295 def skip(self, n): |
| 296 self.lexpos += n |
| 297 |
| 298 # ------------------------------------------------------------ |
| 299 # opttoken() - Return the next token from the Lexer |
| 300 # |
| 301 # Note: This function has been carefully implemented to be as fast |
| 302 # as possible. Don't make changes unless you really know what |
| 303 # you are doing |
| 304 # ------------------------------------------------------------ |
| 305 def token(self): |
| 306 # Make local copies of frequently referenced attributes |
| 307 lexpos = self.lexpos |
| 308 lexlen = self.lexlen |
| 309 lexignore = self.lexignore |
| 310 lexdata = self.lexdata |
| 311 |
| 312 while lexpos < lexlen: |
| 313 # This code provides some short-circuit code for whitespace, tabs, a
nd other ignored characters |
| 314 if lexdata[lexpos] in lexignore: |
| 315 lexpos += 1 |
| 316 continue |
| 317 |
| 318 # Look for a regular expression match |
| 319 for lexre, lexindexfunc in self.lexre: |
| 320 m = lexre.match(lexdata, lexpos) |
| 321 if not m: |
| 322 continue |
| 323 |
| 324 # Create a token for return |
| 325 tok = LexToken() |
| 326 tok.value = m.group() |
| 327 tok.lineno = self.lineno |
| 328 tok.lexpos = lexpos |
| 329 |
| 330 i = m.lastindex |
| 331 func, tok.type = lexindexfunc[i] |
| 332 |
| 333 if not func: |
| 334 # If no token type was set, it's an ignored token |
| 335 if tok.type: |
| 336 self.lexpos = m.end() |
| 337 return tok |
| 338 else: |
| 339 lexpos = m.end() |
| 340 break |
| 341 |
| 342 lexpos = m.end() |
| 343 |
| 344 # If token is processed by a function, call it |
| 345 |
| 346 tok.lexer = self # Set additional attributes useful in toke
n rules |
| 347 self.lexmatch = m |
| 348 self.lexpos = lexpos |
| 349 |
| 350 newtok = func(tok) |
| 351 |
| 352 # Every function must return a token, if nothing, we just move t
o next token |
| 353 if not newtok: |
| 354 lexpos = self.lexpos # This is here in case user
has updated lexpos. |
| 355 lexignore = self.lexignore # This is here in case there
was a state change |
| 356 break |
| 357 |
| 358 # Verify type of the token. If not in the token map, raise an e
rror |
| 359 if not self.lexoptimize: |
| 360 if newtok.type not in self.lextokens_all: |
| 361 raise LexError("%s:%d: Rule '%s' returned an unknown tok
en type '%s'" % ( |
| 362 func.__code__.co_filename, func.__code__.co_firstlin
eno, |
| 363 func.__name__, newtok.type), lexdata[lexpos:]) |
| 364 |
| 365 return newtok |
| 366 else: |
| 367 # No match, see if in literals |
| 368 if lexdata[lexpos] in self.lexliterals: |
| 369 tok = LexToken() |
| 370 tok.value = lexdata[lexpos] |
| 371 tok.lineno = self.lineno |
| 372 tok.type = tok.value |
| 373 tok.lexpos = lexpos |
| 374 self.lexpos = lexpos + 1 |
| 375 return tok |
| 376 |
| 377 # No match. Call t_error() if defined. |
| 378 if self.lexerrorf: |
| 379 tok = LexToken() |
| 380 tok.value = self.lexdata[lexpos:] |
| 381 tok.lineno = self.lineno |
| 382 tok.type = 'error' |
| 383 tok.lexer = self |
| 384 tok.lexpos = lexpos |
| 385 self.lexpos = lexpos |
| 386 newtok = self.lexerrorf(tok) |
| 387 if lexpos == self.lexpos: |
| 388 # Error method didn't change text position at all. This
is an error. |
| 389 raise LexError("Scanning error. Illegal character '%s'"
% (lexdata[lexpos]), lexdata[lexpos:]) |
| 390 lexpos = self.lexpos |
| 391 if not newtok: |
| 392 continue |
| 393 return newtok |
| 394 |
| 395 self.lexpos = lexpos |
| 396 raise LexError("Illegal character '%s' at index %d" % (lexdata[l
expos], lexpos), lexdata[lexpos:]) |
| 397 |
| 398 if self.lexeoff: |
| 399 tok = LexToken() |
| 400 tok.type = 'eof' |
| 401 tok.value = '' |
| 402 tok.lineno = self.lineno |
| 403 tok.lexpos = lexpos |
| 404 tok.lexer = self |
| 405 self.lexpos = lexpos |
| 406 newtok = self.lexeoff(tok) |
| 407 return newtok |
| 408 |
| 409 self.lexpos = lexpos + 1 |
| 410 if self.lexdata is None: |
| 411 raise RuntimeError('No input string given with input()') |
| 412 return None |
| 413 |
| 414 # Iterator interface |
| 415 def __iter__(self): |
| 416 return self |
| 417 |
| 418 def next(self): |
| 419 t = self.token() |
| 420 if t is None: |
| 421 raise StopIteration |
| 422 return t |
| 423 |
| 424 __next__ = next |
| 425 |
| 426 # ----------------------------------------------------------------------------- |
| 427 # ==== Lex Builder === |
| 428 # |
| 429 # The functions and classes below are used to collect lexing information |
| 430 # and build a Lexer object from it. |
| 431 # ----------------------------------------------------------------------------- |
| 432 |
| 433 # ----------------------------------------------------------------------------- |
| 434 # _get_regex(func) |
| 435 # |
| 436 # Returns the regular expression assigned to a function either as a doc string |
| 437 # or as a .regex attribute attached by the @TOKEN decorator. |
| 438 # ----------------------------------------------------------------------------- |
| 439 def _get_regex(func): |
| 440 return getattr(func, 'regex', func.__doc__) |
| 441 |
| 442 # ----------------------------------------------------------------------------- |
| 443 # get_caller_module_dict() |
| 444 # |
| 445 # This function returns a dictionary containing all of the symbols defined withi
n |
| 446 # a caller further down the call stack. This is used to get the environment |
| 447 # associated with the yacc() call if none was provided. |
| 448 # ----------------------------------------------------------------------------- |
| 449 def get_caller_module_dict(levels): |
| 450 f = sys._getframe(levels) |
| 451 ldict = f.f_globals.copy() |
| 452 if f.f_globals != f.f_locals: |
| 453 ldict.update(f.f_locals) |
| 454 return ldict |
| 455 |
| 456 # ----------------------------------------------------------------------------- |
| 457 # _funcs_to_names() |
| 458 # |
| 459 # Given a list of regular expression functions, this converts it to a list |
| 460 # suitable for output to a table file |
| 461 # ----------------------------------------------------------------------------- |
| 462 def _funcs_to_names(funclist, namelist): |
| 463 result = [] |
| 464 for f, name in zip(funclist, namelist): |
| 465 if f and f[0]: |
| 466 result.append((name, f[1])) |
| 467 else: |
| 468 result.append(f) |
| 469 return result |
| 470 |
| 471 # ----------------------------------------------------------------------------- |
| 472 # _names_to_funcs() |
| 473 # |
| 474 # Given a list of regular expression function names, this converts it back to |
| 475 # functions. |
| 476 # ----------------------------------------------------------------------------- |
| 477 def _names_to_funcs(namelist, fdict): |
| 478 result = [] |
| 479 for n in namelist: |
| 480 if n and n[0]: |
| 481 result.append((fdict[n[0]], n[1])) |
| 482 else: |
| 483 result.append(n) |
| 484 return result |
| 485 |
| 486 # ----------------------------------------------------------------------------- |
| 487 # _form_master_re() |
| 488 # |
| 489 # This function takes a list of all of the regex components and attempts to |
| 490 # form the master regular expression. Given limitations in the Python re |
| 491 # module, it may be necessary to break the master regex into separate expression
s. |
| 492 # ----------------------------------------------------------------------------- |
| 493 def _form_master_re(relist, reflags, ldict, toknames): |
| 494 if not relist: |
| 495 return [] |
| 496 regex = '|'.join(relist) |
| 497 try: |
| 498 lexre = re.compile(regex, re.VERBOSE | reflags) |
| 499 |
| 500 # Build the index to function map for the matching engine |
| 501 lexindexfunc = [None] * (max(lexre.groupindex.values()) + 1) |
| 502 lexindexnames = lexindexfunc[:] |
| 503 |
| 504 for f, i in lexre.groupindex.items(): |
| 505 handle = ldict.get(f, None) |
| 506 if type(handle) in (types.FunctionType, types.MethodType): |
| 507 lexindexfunc[i] = (handle, toknames[f]) |
| 508 lexindexnames[i] = f |
| 509 elif handle is not None: |
| 510 lexindexnames[i] = f |
| 511 if f.find('ignore_') > 0: |
| 512 lexindexfunc[i] = (None, None) |
| 513 else: |
| 514 lexindexfunc[i] = (None, toknames[f]) |
| 515 |
| 516 return [(lexre, lexindexfunc)], [regex], [lexindexnames] |
| 517 except Exception: |
| 518 m = int(len(relist)/2) |
| 519 if m == 0: |
| 520 m = 1 |
| 521 llist, lre, lnames = _form_master_re(relist[:m], reflags, ldict, tokname
s) |
| 522 rlist, rre, rnames = _form_master_re(relist[m:], reflags, ldict, tokname
s) |
| 523 return (llist+rlist), (lre+rre), (lnames+rnames) |
| 524 |
| 525 # ----------------------------------------------------------------------------- |
| 526 # def _statetoken(s,names) |
| 527 # |
| 528 # Given a declaration name s of the form "t_" and a dictionary whose keys are |
| 529 # state names, this function returns a tuple (states,tokenname) where states |
| 530 # is a tuple of state names and tokenname is the name of the token. For example
, |
| 531 # calling this with s = "t_foo_bar_SPAM" might return (('foo','bar'),'SPAM') |
| 532 # ----------------------------------------------------------------------------- |
| 533 def _statetoken(s, names): |
| 534 nonstate = 1 |
| 535 parts = s.split('_') |
| 536 for i, part in enumerate(parts[1:], 1): |
| 537 if part not in names and part != 'ANY': |
| 538 break |
| 539 |
| 540 if i > 1: |
| 541 states = tuple(parts[1:i]) |
| 542 else: |
| 543 states = ('INITIAL',) |
| 544 |
| 545 if 'ANY' in states: |
| 546 states = tuple(names) |
| 547 |
| 548 tokenname = '_'.join(parts[i:]) |
| 549 return (states, tokenname) |
| 550 |
| 551 |
| 552 # ----------------------------------------------------------------------------- |
| 553 # LexerReflect() |
| 554 # |
| 555 # This class represents information needed to build a lexer as extracted from a |
| 556 # user's input file. |
| 557 # ----------------------------------------------------------------------------- |
| 558 class LexerReflect(object): |
| 559 def __init__(self, ldict, log=None, reflags=0): |
| 560 self.ldict = ldict |
| 561 self.error_func = None |
| 562 self.tokens = [] |
| 563 self.reflags = reflags |
| 564 self.stateinfo = {'INITIAL': 'inclusive'} |
| 565 self.modules = set() |
| 566 self.error = False |
| 567 self.log = PlyLogger(sys.stderr) if log is None else log |
| 568 |
| 569 # Get all of the basic information |
| 570 def get_all(self): |
| 571 self.get_tokens() |
| 572 self.get_literals() |
| 573 self.get_states() |
| 574 self.get_rules() |
| 575 |
| 576 # Validate all of the information |
| 577 def validate_all(self): |
| 578 self.validate_tokens() |
| 579 self.validate_literals() |
| 580 self.validate_rules() |
| 581 return self.error |
| 582 |
| 583 # Get the tokens map |
| 584 def get_tokens(self): |
| 585 tokens = self.ldict.get('tokens', None) |
| 586 if not tokens: |
| 587 self.log.error('No token list is defined') |
| 588 self.error = True |
| 589 return |
| 590 |
| 591 if not isinstance(tokens, (list, tuple)): |
| 592 self.log.error('tokens must be a list or tuple') |
| 593 self.error = True |
| 594 return |
| 595 |
| 596 if not tokens: |
| 597 self.log.error('tokens is empty') |
| 598 self.error = True |
| 599 return |
| 600 |
| 601 self.tokens = tokens |
| 602 |
| 603 # Validate the tokens |
| 604 def validate_tokens(self): |
| 605 terminals = {} |
| 606 for n in self.tokens: |
| 607 if not _is_identifier.match(n): |
| 608 self.log.error("Bad token name '%s'", n) |
| 609 self.error = True |
| 610 if n in terminals: |
| 611 self.log.warning("Token '%s' multiply defined", n) |
| 612 terminals[n] = 1 |
| 613 |
| 614 # Get the literals specifier |
| 615 def get_literals(self): |
| 616 self.literals = self.ldict.get('literals', '') |
| 617 if not self.literals: |
| 618 self.literals = '' |
| 619 |
| 620 # Validate literals |
| 621 def validate_literals(self): |
| 622 try: |
| 623 for c in self.literals: |
| 624 if not isinstance(c, StringTypes) or len(c) > 1: |
| 625 self.log.error('Invalid literal %s. Must be a single charact
er', repr(c)) |
| 626 self.error = True |
| 627 |
| 628 except TypeError: |
| 629 self.log.error('Invalid literals specification. literals must be a s
equence of characters') |
| 630 self.error = True |
| 631 |
| 632 def get_states(self): |
| 633 self.states = self.ldict.get('states', None) |
| 634 # Build statemap |
| 635 if self.states: |
| 636 if not isinstance(self.states, (tuple, list)): |
| 637 self.log.error('states must be defined as a tuple or list') |
| 638 self.error = True |
| 639 else: |
| 640 for s in self.states: |
| 641 if not isinstance(s, tuple) or len(s) != 2: |
| 642 self.log.error("Invalid state specifier %s. Must be a tu
ple (statename,'exclusive|inclusive')", repr(s)) |
| 643 self.error = True |
| 644 continue |
| 645 name, statetype = s |
| 646 if not isinstance(name, StringTypes): |
| 647 self.log.error('State name %s must be a string', repr(na
me)) |
| 648 self.error = True |
| 649 continue |
| 650 if not (statetype == 'inclusive' or statetype == 'exclusive'
): |
| 651 self.log.error("State type for state %s must be 'inclusi
ve' or 'exclusive'", name) |
| 652 self.error = True |
| 653 continue |
| 654 if name in self.stateinfo: |
| 655 self.log.error("State '%s' already defined", name) |
| 656 self.error = True |
| 657 continue |
| 658 self.stateinfo[name] = statetype |
| 659 |
| 660 # Get all of the symbols with a t_ prefix and sort them into various |
| 661 # categories (functions, strings, error functions, and ignore characters) |
| 662 |
| 663 def get_rules(self): |
| 664 tsymbols = [f for f in self.ldict if f[:2] == 't_'] |
| 665 |
| 666 # Now build up a list of functions and a list of strings |
| 667 self.toknames = {} # Mapping of symbols to token names |
| 668 self.funcsym = {} # Symbols defined as functions |
| 669 self.strsym = {} # Symbols defined as strings |
| 670 self.ignore = {} # Ignore strings by state |
| 671 self.errorf = {} # Error functions by state |
| 672 self.eoff = {} # EOF functions by state |
| 673 |
| 674 for s in self.stateinfo: |
| 675 self.funcsym[s] = [] |
| 676 self.strsym[s] = [] |
| 677 |
| 678 if len(tsymbols) == 0: |
| 679 self.log.error('No rules of the form t_rulename are defined') |
| 680 self.error = True |
| 681 return |
| 682 |
| 683 for f in tsymbols: |
| 684 t = self.ldict[f] |
| 685 states, tokname = _statetoken(f, self.stateinfo) |
| 686 self.toknames[f] = tokname |
| 687 |
| 688 if hasattr(t, '__call__'): |
| 689 if tokname == 'error': |
| 690 for s in states: |
| 691 self.errorf[s] = t |
| 692 elif tokname == 'eof': |
| 693 for s in states: |
| 694 self.eoff[s] = t |
| 695 elif tokname == 'ignore': |
| 696 line = t.__code__.co_firstlineno |
| 697 file = t.__code__.co_filename |
| 698 self.log.error("%s:%d: Rule '%s' must be defined as a string
", file, line, t.__name__) |
| 699 self.error = True |
| 700 else: |
| 701 for s in states: |
| 702 self.funcsym[s].append((f, t)) |
| 703 elif isinstance(t, StringTypes): |
| 704 if tokname == 'ignore': |
| 705 for s in states: |
| 706 self.ignore[s] = t |
| 707 if '\\' in t: |
| 708 self.log.warning("%s contains a literal backslash '\\'",
f) |
| 709 |
| 710 elif tokname == 'error': |
| 711 self.log.error("Rule '%s' must be defined as a function", f) |
| 712 self.error = True |
| 713 else: |
| 714 for s in states: |
| 715 self.strsym[s].append((f, t)) |
| 716 else: |
| 717 self.log.error('%s not defined as a function or string', f) |
| 718 self.error = True |
| 719 |
| 720 # Sort the functions by line number |
| 721 for f in self.funcsym.values(): |
| 722 f.sort(key=lambda x: x[1].__code__.co_firstlineno) |
| 723 |
| 724 # Sort the strings by regular expression length |
| 725 for s in self.strsym.values(): |
| 726 s.sort(key=lambda x: len(x[1]), reverse=True) |
| 727 |
| 728 # Validate all of the t_rules collected |
| 729 def validate_rules(self): |
| 730 for state in self.stateinfo: |
| 731 # Validate all rules defined by functions |
| 732 |
| 733 for fname, f in self.funcsym[state]: |
| 734 line = f.__code__.co_firstlineno |
| 735 file = f.__code__.co_filename |
| 736 module = inspect.getmodule(f) |
| 737 self.modules.add(module) |
| 738 |
| 739 tokname = self.toknames[fname] |
| 740 if isinstance(f, types.MethodType): |
| 741 reqargs = 2 |
| 742 else: |
| 743 reqargs = 1 |
| 744 nargs = f.__code__.co_argcount |
| 745 if nargs > reqargs: |
| 746 self.log.error("%s:%d: Rule '%s' has too many arguments", fi
le, line, f.__name__) |
| 747 self.error = True |
| 748 continue |
| 749 |
| 750 if nargs < reqargs: |
| 751 self.log.error("%s:%d: Rule '%s' requires an argument", file
, line, f.__name__) |
| 752 self.error = True |
| 753 continue |
| 754 |
| 755 if not _get_regex(f): |
| 756 self.log.error("%s:%d: No regular expression defined for rul
e '%s'", file, line, f.__name__) |
| 757 self.error = True |
| 758 continue |
| 759 |
| 760 try: |
| 761 c = re.compile('(?P<%s>%s)' % (fname, _get_regex(f)), re.VER
BOSE | self.reflags) |
| 762 if c.match(''): |
| 763 self.log.error("%s:%d: Regular expression for rule '%s'
matches empty string", file, line, f.__name__) |
| 764 self.error = True |
| 765 except re.error as e: |
| 766 self.log.error("%s:%d: Invalid regular expression for rule '
%s'. %s", file, line, f.__name__, e) |
| 767 if '#' in _get_regex(f): |
| 768 self.log.error("%s:%d. Make sure '#' in rule '%s' is esc
aped with '\\#'", file, line, f.__name__) |
| 769 self.error = True |
| 770 |
| 771 # Validate all rules defined by strings |
| 772 for name, r in self.strsym[state]: |
| 773 tokname = self.toknames[name] |
| 774 if tokname == 'error': |
| 775 self.log.error("Rule '%s' must be defined as a function", na
me) |
| 776 self.error = True |
| 777 continue |
| 778 |
| 779 if tokname not in self.tokens and tokname.find('ignore_') < 0: |
| 780 self.log.error("Rule '%s' defined for an unspecified token %
s", name, tokname) |
| 781 self.error = True |
| 782 continue |
| 783 |
| 784 try: |
| 785 c = re.compile('(?P<%s>%s)' % (name, r), re.VERBOSE | self.r
eflags) |
| 786 if (c.match('')): |
| 787 self.log.error("Regular expression for rule '%s' matches
empty string", name) |
| 788 self.error = True |
| 789 except re.error as e: |
| 790 self.log.error("Invalid regular expression for rule '%s'. %s
", name, e) |
| 791 if '#' in r: |
| 792 self.log.error("Make sure '#' in rule '%s' is escaped wi
th '\\#'", name) |
| 793 self.error = True |
| 794 |
| 795 if not self.funcsym[state] and not self.strsym[state]: |
| 796 self.log.error("No rules defined for state '%s'", state) |
| 797 self.error = True |
| 798 |
| 799 # Validate the error function |
| 800 efunc = self.errorf.get(state, None) |
| 801 if efunc: |
| 802 f = efunc |
| 803 line = f.__code__.co_firstlineno |
| 804 file = f.__code__.co_filename |
| 805 module = inspect.getmodule(f) |
| 806 self.modules.add(module) |
| 807 |
| 808 if isinstance(f, types.MethodType): |
| 809 reqargs = 2 |
| 810 else: |
| 811 reqargs = 1 |
| 812 nargs = f.__code__.co_argcount |
| 813 if nargs > reqargs: |
| 814 self.log.error("%s:%d: Rule '%s' has too many arguments", fi
le, line, f.__name__) |
| 815 self.error = True |
| 816 |
| 817 if nargs < reqargs: |
| 818 self.log.error("%s:%d: Rule '%s' requires an argument", file
, line, f.__name__) |
| 819 self.error = True |
| 820 |
| 821 for module in self.modules: |
| 822 self.validate_module(module) |
| 823 |
| 824 # --------------------------------------------------------------------------
--- |
| 825 # validate_module() |
| 826 # |
| 827 # This checks to see if there are duplicated t_rulename() functions or strin
gs |
| 828 # in the parser input file. This is done using a simple regular expression |
| 829 # match on each line in the source code of the given module. |
| 830 # --------------------------------------------------------------------------
--- |
| 831 |
| 832 def validate_module(self, module): |
| 833 try: |
| 834 lines, linen = inspect.getsourcelines(module) |
| 835 except IOError: |
| 836 return |
| 837 |
| 838 fre = re.compile(r'\s*def\s+(t_[a-zA-Z_0-9]*)\(') |
| 839 sre = re.compile(r'\s*(t_[a-zA-Z_0-9]*)\s*=') |
| 840 |
| 841 counthash = {} |
| 842 linen += 1 |
| 843 for line in lines: |
| 844 m = fre.match(line) |
| 845 if not m: |
| 846 m = sre.match(line) |
| 847 if m: |
| 848 name = m.group(1) |
| 849 prev = counthash.get(name) |
| 850 if not prev: |
| 851 counthash[name] = linen |
| 852 else: |
| 853 filename = inspect.getsourcefile(module) |
| 854 self.log.error('%s:%d: Rule %s redefined. Previously defined
on line %d', filename, linen, name, prev) |
| 855 self.error = True |
| 856 linen += 1 |
| 857 |
| 858 # ----------------------------------------------------------------------------- |
| 859 # lex(module) |
| 860 # |
| 861 # Build all of the regular expression rules from definitions in the supplied mod
ule |
| 862 # ----------------------------------------------------------------------------- |
| 863 def lex(module=None, object=None, debug=False, optimize=False, lextab='lextab', |
| 864 reflags=0, nowarn=False, outputdir=None, debuglog=None, errorlog=None): |
| 865 |
| 866 if lextab is None: |
| 867 lextab = 'lextab' |
| 868 |
| 869 global lexer |
| 870 |
| 871 ldict = None |
| 872 stateinfo = {'INITIAL': 'inclusive'} |
| 873 lexobj = Lexer() |
| 874 lexobj.lexoptimize = optimize |
| 875 global token, input |
| 876 |
| 877 if errorlog is None: |
| 878 errorlog = PlyLogger(sys.stderr) |
| 879 |
| 880 if debug: |
| 881 if debuglog is None: |
| 882 debuglog = PlyLogger(sys.stderr) |
| 883 |
| 884 # Get the module dictionary used for the lexer |
| 885 if object: |
| 886 module = object |
| 887 |
| 888 # Get the module dictionary used for the parser |
| 889 if module: |
| 890 _items = [(k, getattr(module, k)) for k in dir(module)] |
| 891 ldict = dict(_items) |
| 892 # If no __file__ attribute is available, try to obtain it from the __mod
ule__ instead |
| 893 if '__file__' not in ldict: |
| 894 ldict['__file__'] = sys.modules[ldict['__module__']].__file__ |
| 895 else: |
| 896 ldict = get_caller_module_dict(2) |
| 897 |
| 898 # Determine if the module is package of a package or not. |
| 899 # If so, fix the tabmodule setting so that tables load correctly |
| 900 pkg = ldict.get('__package__') |
| 901 if pkg and isinstance(lextab, str): |
| 902 if '.' not in lextab: |
| 903 lextab = pkg + '.' + lextab |
| 904 |
| 905 # Collect parser information from the dictionary |
| 906 linfo = LexerReflect(ldict, log=errorlog, reflags=reflags) |
| 907 linfo.get_all() |
| 908 if not optimize: |
| 909 if linfo.validate_all(): |
| 910 raise SyntaxError("Can't build lexer") |
| 911 |
| 912 if optimize and lextab: |
| 913 try: |
| 914 lexobj.readtab(lextab, ldict) |
| 915 token = lexobj.token |
| 916 input = lexobj.input |
| 917 lexer = lexobj |
| 918 return lexobj |
| 919 |
| 920 except ImportError: |
| 921 pass |
| 922 |
| 923 # Dump some basic debugging information |
| 924 if debug: |
| 925 debuglog.info('lex: tokens = %r', linfo.tokens) |
| 926 debuglog.info('lex: literals = %r', linfo.literals) |
| 927 debuglog.info('lex: states = %r', linfo.stateinfo) |
| 928 |
| 929 # Build a dictionary of valid token names |
| 930 lexobj.lextokens = set() |
| 931 for n in linfo.tokens: |
| 932 lexobj.lextokens.add(n) |
| 933 |
| 934 # Get literals specification |
| 935 if isinstance(linfo.literals, (list, tuple)): |
| 936 lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals) |
| 937 else: |
| 938 lexobj.lexliterals = linfo.literals |
| 939 |
| 940 lexobj.lextokens_all = lexobj.lextokens | set(lexobj.lexliterals) |
| 941 |
| 942 # Get the stateinfo dictionary |
| 943 stateinfo = linfo.stateinfo |
| 944 |
| 945 regexs = {} |
| 946 # Build the master regular expressions |
| 947 for state in stateinfo: |
| 948 regex_list = [] |
| 949 |
| 950 # Add rules defined by functions first |
| 951 for fname, f in linfo.funcsym[state]: |
| 952 line = f.__code__.co_firstlineno |
| 953 file = f.__code__.co_filename |
| 954 regex_list.append('(?P<%s>%s)' % (fname, _get_regex(f))) |
| 955 if debug: |
| 956 debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", fname,
_get_regex(f), state) |
| 957 |
| 958 # Now add all of the simple rules |
| 959 for name, r in linfo.strsym[state]: |
| 960 regex_list.append('(?P<%s>%s)' % (name, r)) |
| 961 if debug: |
| 962 debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", name,
r, state) |
| 963 |
| 964 regexs[state] = regex_list |
| 965 |
| 966 # Build the master regular expressions |
| 967 |
| 968 if debug: |
| 969 debuglog.info('lex: ==== MASTER REGEXS FOLLOW ====') |
| 970 |
| 971 for state in regexs: |
| 972 lexre, re_text, re_names = _form_master_re(regexs[state], reflags, ldict
, linfo.toknames) |
| 973 lexobj.lexstatere[state] = lexre |
| 974 lexobj.lexstateretext[state] = re_text |
| 975 lexobj.lexstaterenames[state] = re_names |
| 976 if debug: |
| 977 for i, text in enumerate(re_text): |
| 978 debuglog.info("lex: state '%s' : regex[%d] = '%s'", state, i, te
xt) |
| 979 |
| 980 # For inclusive states, we need to add the regular expressions from the INIT
IAL state |
| 981 for state, stype in stateinfo.items(): |
| 982 if state != 'INITIAL' and stype == 'inclusive': |
| 983 lexobj.lexstatere[state].extend(lexobj.lexstatere['INITIAL']) |
| 984 lexobj.lexstateretext[state].extend(lexobj.lexstateretext['INITIAL']
) |
| 985 lexobj.lexstaterenames[state].extend(lexobj.lexstaterenames['INITIAL
']) |
| 986 |
| 987 lexobj.lexstateinfo = stateinfo |
| 988 lexobj.lexre = lexobj.lexstatere['INITIAL'] |
| 989 lexobj.lexretext = lexobj.lexstateretext['INITIAL'] |
| 990 lexobj.lexreflags = reflags |
| 991 |
| 992 # Set up ignore variables |
| 993 lexobj.lexstateignore = linfo.ignore |
| 994 lexobj.lexignore = lexobj.lexstateignore.get('INITIAL', '') |
| 995 |
| 996 # Set up error functions |
| 997 lexobj.lexstateerrorf = linfo.errorf |
| 998 lexobj.lexerrorf = linfo.errorf.get('INITIAL', None) |
| 999 if not lexobj.lexerrorf: |
| 1000 errorlog.warning('No t_error rule is defined') |
| 1001 |
| 1002 # Set up eof functions |
| 1003 lexobj.lexstateeoff = linfo.eoff |
| 1004 lexobj.lexeoff = linfo.eoff.get('INITIAL', None) |
| 1005 |
| 1006 # Check state information for ignore and error rules |
| 1007 for s, stype in stateinfo.items(): |
| 1008 if stype == 'exclusive': |
| 1009 if s not in linfo.errorf: |
| 1010 errorlog.warning("No error rule is defined for exclusive state '
%s'", s) |
| 1011 if s not in linfo.ignore and lexobj.lexignore: |
| 1012 errorlog.warning("No ignore rule is defined for exclusive state
'%s'", s) |
| 1013 elif stype == 'inclusive': |
| 1014 if s not in linfo.errorf: |
| 1015 linfo.errorf[s] = linfo.errorf.get('INITIAL', None) |
| 1016 if s not in linfo.ignore: |
| 1017 linfo.ignore[s] = linfo.ignore.get('INITIAL', '') |
| 1018 |
| 1019 # Create global versions of the token() and input() functions |
| 1020 token = lexobj.token |
| 1021 input = lexobj.input |
| 1022 lexer = lexobj |
| 1023 |
| 1024 # If in optimize mode, we write the lextab |
| 1025 if lextab and optimize: |
| 1026 if outputdir is None: |
| 1027 # If no output directory is set, the location of the output files |
| 1028 # is determined according to the following rules: |
| 1029 # - If lextab specifies a package, files go into that package di
rectory |
| 1030 # - Otherwise, files go in the same directory as the specifying
module |
| 1031 if isinstance(lextab, types.ModuleType): |
| 1032 srcfile = lextab.__file__ |
| 1033 else: |
| 1034 if '.' not in lextab: |
| 1035 srcfile = ldict['__file__'] |
| 1036 else: |
| 1037 parts = lextab.split('.') |
| 1038 pkgname = '.'.join(parts[:-1]) |
| 1039 exec('import %s' % pkgname) |
| 1040 srcfile = getattr(sys.modules[pkgname], '__file__', '') |
| 1041 outputdir = os.path.dirname(srcfile) |
| 1042 try: |
| 1043 lexobj.writetab(lextab, outputdir) |
| 1044 except IOError as e: |
| 1045 errorlog.warning("Couldn't write lextab module %r. %s" % (lextab, e)
) |
| 1046 |
| 1047 return lexobj |
| 1048 |
| 1049 # ----------------------------------------------------------------------------- |
| 1050 # runmain() |
| 1051 # |
| 1052 # This runs the lexer as a main program |
| 1053 # ----------------------------------------------------------------------------- |
| 1054 |
| 1055 def runmain(lexer=None, data=None): |
| 1056 if not data: |
| 1057 try: |
| 1058 filename = sys.argv[1] |
| 1059 f = open(filename) |
| 1060 data = f.read() |
| 1061 f.close() |
| 1062 except IndexError: |
| 1063 sys.stdout.write('Reading from standard input (type EOF to end):\n') |
| 1064 data = sys.stdin.read() |
| 1065 |
| 1066 if lexer: |
| 1067 _input = lexer.input |
| 1068 else: |
| 1069 _input = input |
| 1070 _input(data) |
| 1071 if lexer: |
| 1072 _token = lexer.token |
| 1073 else: |
| 1074 _token = token |
| 1075 |
| 1076 while True: |
| 1077 tok = _token() |
| 1078 if not tok: |
| 1079 break |
| 1080 sys.stdout.write('(%s,%r,%d,%d)\n' % (tok.type, tok.value, tok.lineno, t
ok.lexpos)) |
| 1081 |
| 1082 # ----------------------------------------------------------------------------- |
| 1083 # @TOKEN(regex) |
| 1084 # |
| 1085 # This decorator function can be used to set the regex expression on a function |
| 1086 # when its docstring might need to be set in an alternative way |
| 1087 # ----------------------------------------------------------------------------- |
| 1088 |
| 1089 def TOKEN(r): |
| 1090 def set_regex(f): |
| 1091 if hasattr(r, '__call__'): |
| 1092 f.regex = _get_regex(r) |
| 1093 else: |
| 1094 f.regex = r |
| 1095 return f |
| 1096 return set_regex |
| 1097 |
| 1098 # Alternative spelling of the TOKEN decorator |
| 1099 Token = TOKEN |
| 1100 |
OLD | NEW |