Edit: lex.py
# ----------------------------------------------------------------------------- # ply: lex.py # # Copyright (C) 2001-2016 # David M. Beazley (Dabeaz LLC) # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are # met: # # * Redistributions of source code must retain the above copyright notice, # this list of conditions and the following disclaimer. # * Redistributions in binary form must reproduce the above copyright notice, # this list of conditions and the following disclaimer in the documentation # and/or other materials provided with the distribution. # * Neither the name of the David Beazley or Dabeaz LLC may be used to # endorse or promote products derived from this software without # specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # ----------------------------------------------------------------------------- __version__ = '3.9' __tabversion__ = '3.8' import re import sys import types import copy import os import inspect # This tuple contains known string types try: # Python 2.6 StringTypes = (types.StringType, types.UnicodeType) except AttributeError: # Python 3.0 StringTypes = (str, bytes) # This regular expression is used to match valid token names _is_identifier = re.compile(r'^[a-zA-Z0-9_]+$') # Exception thrown when invalid token encountered and no default error # handler is defined. class LexError(Exception): def __init__(self, message, s): self.args = (message,) self.text = s # Token class. This class is used to represent the tokens produced. class LexToken(object): def __str__(self): return 'LexToken(%s,%r,%d,%d)' % (self.type, self.value, self.lineno, self.lexpos) def __repr__(self): return str(self) # This object is a stand-in for a logging object created by the # logging module. class PlyLogger(object): def __init__(self, f): self.f = f def critical(self, msg, *args, **kwargs): self.f.write((msg % args) + '\n') def warning(self, msg, *args, **kwargs): self.f.write('WARNING: ' + (msg % args) + '\n') def error(self, msg, *args, **kwargs): self.f.write('ERROR: ' + (msg % args) + '\n') info = critical debug = critical # Null logger is used when no output is generated. Does nothing. class NullLogger(object): def __getattribute__(self, name): return self def __call__(self, *args, **kwargs): return self # ----------------------------------------------------------------------------- # === Lexing Engine === # # The following Lexer class implements the lexer runtime. There are only # a few public methods and attributes: # # input() - Store a new string in the lexer # token() - Get the next token # clone() - Clone the lexer # # lineno - Current line number # lexpos - Current position in the input string # ----------------------------------------------------------------------------- class Lexer: def __init__(self): self.lexre = None # Master regular expression. This is a list of # tuples (re, findex) where re is a compiled # regular expression and findex is a list # mapping regex group numbers to rules self.lexretext = None # Current regular expression strings self.lexstatere = {} # Dictionary mapping lexer states to master regexs self.lexstateretext = {} # Dictionary mapping lexer states to regex strings self.lexstaterenames = {} # Dictionary mapping lexer states to symbol names self.lexstate = 'INITIAL' # Current lexer state self.lexstatestack = [] # Stack of lexer states self.lexstateinfo = None # State information self.lexstateignore = {} # Dictionary of ignored characters for each state self.lexstateerrorf = {} # Dictionary of error functions for each state self.lexstateeoff = {} # Dictionary of eof functions for each state self.lexreflags = 0 # Optional re compile flags self.lexdata = None # Actual input data (as a string) self.lexpos = 0 # Current position in input text self.lexlen = 0 # Length of the input text self.lexerrorf = None # Error rule (if any) self.lexeoff = None # EOF rule (if any) self.lextokens = None # List of valid tokens self.lexignore = '' # Ignored characters self.lexliterals = '' # Literal characters that can be passed through self.lexmodule = None # Module self.lineno = 1 # Current line number self.lexoptimize = False # Optimized mode def clone(self, object=None): c = copy.copy(self) # If the object parameter has been supplied, it means we are attaching the # lexer to a new object. In this case, we have to rebind all methods in # the lexstatere and lexstateerrorf tables. if object: newtab = {} for key, ritem in self.lexstatere.items(): newre = [] for cre, findex in ritem: newfindex = [] for f in findex: if not f or not f[0]: newfindex.append(f) continue newfindex.append((getattr(object, f[0].__name__), f[1])) newre.append((cre, newfindex)) newtab[key] = newre c.lexstatere = newtab c.lexstateerrorf = {} for key, ef in self.lexstateerrorf.items(): c.lexstateerrorf[key] = getattr(object, ef.__name__) c.lexmodule = object return c # ------------------------------------------------------------ # writetab() - Write lexer information to a table file # ------------------------------------------------------------ def writetab(self, lextab, outputdir=''): if isinstance(lextab, types.ModuleType): raise IOError("Won't overwrite existing lextab module") basetabmodule = lextab.split('.')[-1] filename = os.path.join(outputdir, basetabmodule) + '.py' with open(filename, 'w') as tf: tf.write('# %s.py. This file automatically created by PLY (version %s). Don\'t edit!\n' % (basetabmodule, __version__)) tf.write('_tabversion = %s\n' % repr(__tabversion__)) tf.write('_lextokens = set(%s)\n' % repr(tuple(self.lextokens))) tf.write('_lexreflags = %s\n' % repr(self.lexreflags)) tf.write('_lexliterals = %s\n' % repr(self.lexliterals)) tf.write('_lexstateinfo = %s\n' % repr(self.lexstateinfo)) # Rewrite the lexstatere table, replacing function objects with function names tabre = {} for statename, lre in self.lexstatere.items(): titem = [] for (pat, func), retext, renames in zip(lre, self.lexstateretext[statename], self.lexstaterenames[statename]): titem.append((retext, _funcs_to_names(func, renames))) tabre[statename] = titem tf.write('_lexstatere = %s\n' % repr(tabre)) tf.write('_lexstateignore = %s\n' % repr(self.lexstateignore)) taberr = {} for statename, ef in self.lexstateerrorf.items(): taberr[statename] = ef.__name__ if ef else None tf.write('_lexstateerrorf = %s\n' % repr(taberr)) tabeof = {} for statename, ef in self.lexstateeoff.items(): tabeof[statename] = ef.__name__ if ef else None tf.write('_lexstateeoff = %s\n' % repr(tabeof)) # ------------------------------------------------------------ # readtab() - Read lexer information from a tab file # ------------------------------------------------------------ def readtab(self, tabfile, fdict): if isinstance(tabfile, types.ModuleType): lextab = tabfile else: exec('import %s' % tabfile) lextab = sys.modules[tabfile] if getattr(lextab, '_tabversion', '0.0') != __tabversion__: raise ImportError('Inconsistent PLY version') self.lextokens = lextab._lextokens self.lexreflags = lextab._lexreflags self.lexliterals = lextab._lexliterals self.lextokens_all = self.lextokens | set(self.lexliterals) self.lexstateinfo = lextab._lexstateinfo self.lexstateignore = lextab._lexstateignore self.lexstatere = {} self.lexstateretext = {} for statename, lre in lextab._lexstatere.items(): titem = [] txtitem = [] for pat, func_name in lre: titem.append((re.compile(pat, lextab._lexreflags | re.VERBOSE), _names_to_funcs(func_name, fdict))) self.lexstatere[statename] = titem self.lexstateretext[statename] = txtitem self.lexstateerrorf = {} for statename, ef in lextab._lexstateerrorf.items(): self.lexstateerrorf[statename] = fdict[ef] self.lexstateeoff = {} for statename, ef in lextab._lexstateeoff.items(): self.lexstateeoff[statename] = fdict[ef] self.begin('INITIAL') # ------------------------------------------------------------ # input() - Push a new string into the lexer # ------------------------------------------------------------ def input(self, s): # Pull off the first character to see if s looks like a string c = s[:1] if not isinstance(c, StringTypes): raise ValueError('Expected a string') self.lexdata = s self.lexpos = 0 self.lexlen = len(s) # ------------------------------------------------------------ # begin() - Changes the lexing state # ------------------------------------------------------------ def begin(self, state): if state not in self.lexstatere: raise ValueError('Undefined state') self.lexre = self.lexstatere[state] self.lexretext = self.lexstateretext[state] self.lexignore = self.lexstateignore.get(state, '') self.lexerrorf = self.lexstateerrorf.get(state, None) self.lexeoff = self.lexstateeoff.get(state, None) self.lexstate = state # ------------------------------------------------------------ # push_state() - Changes the lexing state and saves old on stack # ------------------------------------------------------------ def push_state(self, state): self.lexstatestack.append(self.lexstate) self.begin(state) # ------------------------------------------------------------ # pop_state() - Restores the previous state # ------------------------------------------------------------ def pop_state(self): self.begin(self.lexstatestack.pop()) # ------------------------------------------------------------ # current_state() - Returns the current lexing state # ------------------------------------------------------------ def current_state(self): return self.lexstate # ------------------------------------------------------------ # skip() - Skip ahead n characters # ------------------------------------------------------------ def skip(self, n): self.lexpos += n # ------------------------------------------------------------ # opttoken() - Return the next token from the Lexer # # Note: This function has been carefully implemented to be as fast # as possible. Don't make changes unless you really know what # you are doing # ------------------------------------------------------------ def token(self): # Make local copies of frequently referenced attributes lexpos = self.lexpos lexlen = self.lexlen lexignore = self.lexignore lexdata = self.lexdata while lexpos < lexlen: # This code provides some short-circuit code for whitespace, tabs, and other ignored characters if lexdata[lexpos] in lexignore: lexpos += 1 continue # Look for a regular expression match for lexre, lexindexfunc in self.lexre: m = lexre.match(lexdata, lexpos) if not m: continue # Create a token for return tok = LexToken() tok.value = m.group() tok.lineno = self.lineno tok.lexpos = lexpos i = m.lastindex func, tok.type = lexindexfunc[i] if not func: # If no token type was set, it's an ignored token if tok.type: self.lexpos = m.end() return tok else: lexpos = m.end() break lexpos = m.end() # If token is processed by a function, call it tok.lexer = self # Set additional attributes useful in token rules self.lexmatch = m self.lexpos = lexpos newtok = func(tok) # Every function must return a token, if nothing, we just move to next token if not newtok: lexpos = self.lexpos # This is here in case user has updated lexpos. lexignore = self.lexignore # This is here in case there was a state change break # Verify type of the token. If not in the token map, raise an error if not self.lexoptimize: if newtok.type not in self.lextokens_all: raise LexError("%s:%d: Rule '%s' returned an unknown token type '%s'" % ( func.__code__.co_filename, func.__code__.co_firstlineno, func.__name__, newtok.type), lexdata[lexpos:]) return newtok else: # No match, see if in literals if lexdata[lexpos] in self.lexliterals: tok = LexToken() tok.value = lexdata[lexpos] tok.lineno = self.lineno tok.type = tok.value tok.lexpos = lexpos self.lexpos = lexpos + 1 return tok # No match. Call t_error() if defined. if self.lexerrorf: tok = LexToken() tok.value = self.lexdata[lexpos:] tok.lineno = self.lineno tok.type = 'error' tok.lexer = self tok.lexpos = lexpos self.lexpos = lexpos newtok = self.lexerrorf(tok) if lexpos == self.lexpos: # Error method didn't change text position at all. This is an error. raise LexError("Scanning error. Illegal character '%s'" % (lexdata[lexpos]), lexdata[lexpos:]) lexpos = self.lexpos if not newtok: continue return newtok self.lexpos = lexpos raise LexError("Illegal character '%s' at index %d" % (lexdata[lexpos], lexpos), lexdata[lexpos:]) if self.lexeoff: tok = LexToken() tok.type = 'eof' tok.value = '' tok.lineno = self.lineno tok.lexpos = lexpos tok.lexer = self self.lexpos = lexpos newtok = self.lexeoff(tok) return newtok self.lexpos = lexpos + 1 if self.lexdata is None: raise RuntimeError('No input string given with input()') return None # Iterator interface def __iter__(self): return self def next(self): t = self.token() if t is None: raise StopIteration return t __next__ = next # ----------------------------------------------------------------------------- # ==== Lex Builder === # # The functions and classes below are used to collect lexing information # and build a Lexer object from it. # ----------------------------------------------------------------------------- # ----------------------------------------------------------------------------- # _get_regex(func) # # Returns the regular expression assigned to a function either as a doc string # or as a .regex attribute attached by the @TOKEN decorator. # ----------------------------------------------------------------------------- def _get_regex(func): return getattr(func, 'regex', func.__doc__) # ----------------------------------------------------------------------------- # get_caller_module_dict() # # This function returns a dictionary containing all of the symbols defined within # a caller further down the call stack. This is used to get the environment # associated with the yacc() call if none was provided. # ----------------------------------------------------------------------------- def get_caller_module_dict(levels): f = sys._getframe(levels) ldict = f.f_globals.copy() if f.f_globals != f.f_locals: ldict.update(f.f_locals) return ldict # ----------------------------------------------------------------------------- # _funcs_to_names() # # Given a list of regular expression functions, this converts it to a list # suitable for output to a table file # ----------------------------------------------------------------------------- def _funcs_to_names(funclist, namelist): result = [] for f, name in zip(funclist, namelist): if f and f[0]: result.append((name, f[1])) else: result.append(f) return result # ----------------------------------------------------------------------------- # _names_to_funcs() # # Given a list of regular expression function names, this converts it back to # functions. # ----------------------------------------------------------------------------- def _names_to_funcs(namelist, fdict): result = [] for n in namelist: if n and n[0]: result.append((fdict[n[0]], n[1])) else: result.append(n) return result # ----------------------------------------------------------------------------- # _form_master_re() # # This function takes a list of all of the regex components and attempts to # form the master regular expression. Given limitations in the Python re # module, it may be necessary to break the master regex into separate expressions. # ----------------------------------------------------------------------------- def _form_master_re(relist, reflags, ldict, toknames): if not relist: return [] regex = '|'.join(relist) try: lexre = re.compile(regex, re.VERBOSE | reflags) # Build the index to function map for the matching engine lexindexfunc = [None] * (max(lexre.groupindex.values()) + 1) lexindexnames = lexindexfunc[:] for f, i in lexre.groupindex.items(): handle = ldict.get(f, None) if type(handle) in (types.FunctionType, types.MethodType): lexindexfunc[i] = (handle, toknames[f]) lexindexnames[i] = f elif handle is not None: lexindexnames[i] = f if f.find('ignore_') > 0: lexindexfunc[i] = (None, None) else: lexindexfunc[i] = (None, toknames[f]) return [(lexre, lexindexfunc)], [regex], [lexindexnames] except Exception: m = int(len(relist)/2) if m == 0: m = 1 llist, lre, lnames = _form_master_re(relist[:m], reflags, ldict, toknames) rlist, rre, rnames = _form_master_re(relist[m:], reflags, ldict, toknames) return (llist+rlist), (lre+rre), (lnames+rnames) # ----------------------------------------------------------------------------- # def _statetoken(s,names) # # Given a declaration name s of the form "t_" and a dictionary whose keys are # state names, this function returns a tuple (states,tokenname) where states # is a tuple of state names and tokenname is the name of the token. For example, # calling this with s = "t_foo_bar_SPAM" might return (('foo','bar'),'SPAM') # ----------------------------------------------------------------------------- def _statetoken(s, names): nonstate = 1 parts = s.split('_') for i, part in enumerate(parts[1:], 1): if part not in names and part != 'ANY': break if i > 1: states = tuple(parts[1:i]) else: states = ('INITIAL',) if 'ANY' in states: states = tuple(names) tokenname = '_'.join(parts[i:]) return (states, tokenname) # ----------------------------------------------------------------------------- # LexerReflect() # # This class represents information needed to build a lexer as extracted from a # user's input file. # ----------------------------------------------------------------------------- class LexerReflect(object): def __init__(self, ldict, log=None, reflags=0): self.ldict = ldict self.error_func = None self.tokens = [] self.reflags = reflags self.stateinfo = {'INITIAL': 'inclusive'} self.modules = set() self.error = False self.log = PlyLogger(sys.stderr) if log is None else log # Get all of the basic information def get_all(self): self.get_tokens() self.get_literals() self.get_states() self.get_rules() # Validate all of the information def validate_all(self): self.validate_tokens() self.validate_literals() self.validate_rules() return self.error # Get the tokens map def get_tokens(self): tokens = self.ldict.get('tokens', None) if not tokens: self.log.error('No token list is defined') self.error = True return if not isinstance(tokens, (list, tuple)): self.log.error('tokens must be a list or tuple') self.error = True return if not tokens: self.log.error('tokens is empty') self.error = True return self.tokens = tokens # Validate the tokens def validate_tokens(self): terminals = {} for n in self.tokens: if not _is_identifier.match(n): self.log.error("Bad token name '%s'", n) self.error = True if n in terminals: self.log.warning("Token '%s' multiply defined", n) terminals[n] = 1 # Get the literals specifier def get_literals(self): self.literals = self.ldict.get('literals', '') if not self.literals: self.literals = '' # Validate literals def validate_literals(self): try: for c in self.literals: if not isinstance(c, StringTypes) or len(c) > 1: self.log.error('Invalid literal %s. Must be a single character', repr(c)) self.error = True except TypeError: self.log.error('Invalid literals specification. literals must be a sequence of characters') self.error = True def get_states(self): self.states = self.ldict.get('states', None) # Build statemap if self.states: if not isinstance(self.states, (tuple, list)): self.log.error('states must be defined as a tuple or list') self.error = True else: for s in self.states: if not isinstance(s, tuple) or len(s) != 2: self.log.error("Invalid state specifier %s. Must be a tuple (statename,'exclusive|inclusive')", repr(s)) self.error = True continue name, statetype = s if not isinstance(name, StringTypes): self.log.error('State name %s must be a string', repr(name)) self.error = True continue if not (statetype == 'inclusive' or statetype == 'exclusive'): self.log.error("State type for state %s must be 'inclusive' or 'exclusive'", name) self.error = True continue if name in self.stateinfo: self.log.error("State '%s' already defined", name) self.error = True continue self.stateinfo[name] = statetype # Get all of the symbols with a t_ prefix and sort them into various # categories (functions, strings, error functions, and ignore characters) def get_rules(self): tsymbols = [f for f in self.ldict if f[:2] == 't_'] # Now build up a list of functions and a list of strings self.toknames = {} # Mapping of symbols to token names self.funcsym = {} # Symbols defined as functions self.strsym = {} # Symbols defined as strings self.ignore = {} # Ignore strings by state self.errorf = {} # Error functions by state self.eoff = {} # EOF functions by state for s in self.stateinfo: self.funcsym[s] = [] self.strsym[s] = [] if len(tsymbols) == 0: self.log.error('No rules of the form t_rulename are defined') self.error = True return for f in tsymbols: t = self.ldict[f] states, tokname = _statetoken(f, self.stateinfo) self.toknames[f] = tokname if hasattr(t, '__call__'): if tokname == 'error': for s in states: self.errorf[s] = t elif tokname == 'eof': for s in states: self.eoff[s] = t elif tokname == 'ignore': line = t.__code__.co_firstlineno file = t.__code__.co_filename self.log.error("%s:%d: Rule '%s' must be defined as a string", file, line, t.__name__) self.error = True else: for s in states: self.funcsym[s].append((f, t)) elif isinstance(t, StringTypes): if tokname == 'ignore': for s in states: self.ignore[s] = t if '\\' in t: self.log.warning("%s contains a literal backslash '\\'", f) elif tokname == 'error': self.log.error("Rule '%s' must be defined as a function", f) self.error = True else: for s in states: self.strsym[s].append((f, t)) else: self.log.error('%s not defined as a function or string', f) self.error = True # Sort the functions by line number for f in self.funcsym.values(): f.sort(key=lambda x: x[1].__code__.co_firstlineno) # Sort the strings by regular expression length for s in self.strsym.values(): s.sort(key=lambda x: len(x[1]), reverse=True) # Validate all of the t_rules collected def validate_rules(self): for state in self.stateinfo: # Validate all rules defined by functions for fname, f in self.funcsym[state]: line = f.__code__.co_firstlineno file = f.__code__.co_filename module = inspect.getmodule(f) self.modules.add(module) tokname = self.toknames[fname] if isinstance(f, types.MethodType): reqargs = 2 else: reqargs = 1 nargs = f.__code__.co_argcount if nargs > reqargs: self.log.error("%s:%d: Rule '%s' has too many arguments", file, line, f.__name__) self.error = True continue if nargs < reqargs: self.log.error("%s:%d: Rule '%s' requires an argument", file, line, f.__name__) self.error = True continue if not _get_regex(f): self.log.error("%s:%d: No regular expression defined for rule '%s'", file, line, f.__name__) self.error = True continue try: c = re.compile('(?P<%s>%s)' % (fname, _get_regex(f)), re.VERBOSE | self.reflags) if c.match(''): self.log.error("%s:%d: Regular expression for rule '%s' matches empty string", file, line, f.__name__) self.error = True except re.error as e: self.log.error("%s:%d: Invalid regular expression for rule '%s'. %s", file, line, f.__name__, e) if '#' in _get_regex(f): self.log.error("%s:%d. Make sure '#' in rule '%s' is escaped with '\\#'", file, line, f.__name__) self.error = True # Validate all rules defined by strings for name, r in self.strsym[state]: tokname = self.toknames[name] if tokname == 'error': self.log.error("Rule '%s' must be defined as a function", name) self.error = True continue if tokname not in self.tokens and tokname.find('ignore_') < 0: self.log.error("Rule '%s' defined for an unspecified token %s", name, tokname) self.error = True continue try: c = re.compile('(?P<%s>%s)' % (name, r), re.VERBOSE | self.reflags) if (c.match('')): self.log.error("Regular expression for rule '%s' matches empty string", name) self.error = True except re.error as e: self.log.error("Invalid regular expression for rule '%s'. %s", name, e) if '#' in r: self.log.error("Make sure '#' in rule '%s' is escaped with '\\#'", name) self.error = True if not self.funcsym[state] and not self.strsym[state]: self.log.error("No rules defined for state '%s'", state) self.error = True # Validate the error function efunc = self.errorf.get(state, None) if efunc: f = efunc line = f.__code__.co_firstlineno file = f.__code__.co_filename module = inspect.getmodule(f) self.modules.add(module) if isinstance(f, types.MethodType): reqargs = 2 else: reqargs = 1 nargs = f.__code__.co_argcount if nargs > reqargs: self.log.error("%s:%d: Rule '%s' has too many arguments", file, line, f.__name__) self.error = True if nargs < reqargs: self.log.error("%s:%d: Rule '%s' requires an argument", file, line, f.__name__) self.error = True for module in self.modules: self.validate_module(module) # ----------------------------------------------------------------------------- # validate_module() # # This checks to see if there are duplicated t_rulename() functions or strings # in the parser input file. This is done using a simple regular expression # match on each line in the source code of the given module. # ----------------------------------------------------------------------------- def validate_module(self, module): try: lines, linen = inspect.getsourcelines(module) except IOError: return fre = re.compile(r'\s*def\s+(t_[a-zA-Z_0-9]*)\(') sre = re.compile(r'\s*(t_[a-zA-Z_0-9]*)\s*=') counthash = {} linen += 1 for line in lines: m = fre.match(line) if not m: m = sre.match(line) if m: name = m.group(1) prev = counthash.get(name) if not prev: counthash[name] = linen else: filename = inspect.getsourcefile(module) self.log.error('%s:%d: Rule %s redefined. Previously defined on line %d', filename, linen, name, prev) self.error = True linen += 1 # ----------------------------------------------------------------------------- # lex(module) # # Build all of the regular expression rules from definitions in the supplied module # ----------------------------------------------------------------------------- def lex(module=None, object=None, debug=False, optimize=False, lextab='lextab', reflags=0, nowarn=False, outputdir=None, debuglog=None, errorlog=None): if lextab is None: lextab = 'lextab' global lexer ldict = None stateinfo = {'INITIAL': 'inclusive'} lexobj = Lexer() lexobj.lexoptimize = optimize global token, input if errorlog is None: errorlog = PlyLogger(sys.stderr) if debug: if debuglog is None: debuglog = PlyLogger(sys.stderr) # Get the module dictionary used for the lexer if object: module = object # Get the module dictionary used for the parser if module: _items = [(k, getattr(module, k)) for k in dir(module)] ldict = dict(_items) # If no __file__ attribute is available, try to obtain it from the __module__ instead if '__file__' not in ldict: ldict['__file__'] = sys.modules[ldict['__module__']].__file__ else: ldict = get_caller_module_dict(2) # Determine if the module is package of a package or not. # If so, fix the tabmodule setting so that tables load correctly pkg = ldict.get('__package__') if pkg and isinstance(lextab, str): if '.' not in lextab: lextab = pkg + '.' + lextab # Collect parser information from the dictionary linfo = LexerReflect(ldict, log=errorlog, reflags=reflags) linfo.get_all() if not optimize: if linfo.validate_all(): raise SyntaxError("Can't build lexer") if optimize and lextab: try: lexobj.readtab(lextab, ldict) token = lexobj.token input = lexobj.input lexer = lexobj return lexobj except ImportError: pass # Dump some basic debugging information if debug: debuglog.info('lex: tokens = %r', linfo.tokens) debuglog.info('lex: literals = %r', linfo.literals) debuglog.info('lex: states = %r', linfo.stateinfo) # Build a dictionary of valid token names lexobj.lextokens = set() for n in linfo.tokens: lexobj.lextokens.add(n) # Get literals specification if isinstance(linfo.literals, (list, tuple)): lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals) else: lexobj.lexliterals = linfo.literals lexobj.lextokens_all = lexobj.lextokens | set(lexobj.lexliterals) # Get the stateinfo dictionary stateinfo = linfo.stateinfo regexs = {} # Build the master regular expressions for state in stateinfo: regex_list = [] # Add rules defined by functions first for fname, f in linfo.funcsym[state]: line = f.__code__.co_firstlineno file = f.__code__.co_filename regex_list.append('(?P<%s>%s)' % (fname, _get_regex(f))) if debug: debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", fname, _get_regex(f), state) # Now add all of the simple rules for name, r in linfo.strsym[state]: regex_list.append('(?P<%s>%s)' % (name, r)) if debug: debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", name, r, state) regexs[state] = regex_list # Build the master regular expressions if debug: debuglog.info('lex: ==== MASTER REGEXS FOLLOW ====') for state in regexs: lexre, re_text, re_names = _form_master_re(regexs[state], reflags, ldict, linfo.toknames) lexobj.lexstatere[state] = lexre lexobj.lexstateretext[state] = re_text lexobj.lexstaterenames[state] = re_names if debug: for i, text in enumerate(re_text): debuglog.info("lex: state '%s' : regex[%d] = '%s'", state, i, text) # For inclusive states, we need to add the regular expressions from the INITIAL state for state, stype in stateinfo.items(): if state != 'INITIAL' and stype == 'inclusive': lexobj.lexstatere[state].extend(lexobj.lexstatere['INITIAL']) lexobj.lexstateretext[state].extend(lexobj.lexstateretext['INITIAL']) lexobj.lexstaterenames[state].extend(lexobj.lexstaterenames['INITIAL']) lexobj.lexstateinfo = stateinfo lexobj.lexre = lexobj.lexstatere['INITIAL'] lexobj.lexretext = lexobj.lexstateretext['INITIAL'] lexobj.lexreflags = reflags # Set up ignore variables lexobj.lexstateignore = linfo.ignore lexobj.lexignore = lexobj.lexstateignore.get('INITIAL', '') # Set up error functions lexobj.lexstateerrorf = linfo.errorf lexobj.lexerrorf = linfo.errorf.get('INITIAL', None) if not lexobj.lexerrorf: errorlog.warning('No t_error rule is defined') # Set up eof functions lexobj.lexstateeoff = linfo.eoff lexobj.lexeoff = linfo.eoff.get('INITIAL', None) # Check state information for ignore and error rules for s, stype in stateinfo.items(): if stype == 'exclusive': if s not in linfo.errorf: errorlog.warning("No error rule is defined for exclusive state '%s'", s) if s not in linfo.ignore and lexobj.lexignore: errorlog.warning("No ignore rule is defined for exclusive state '%s'", s) elif stype == 'inclusive': if s not in linfo.errorf: linfo.errorf[s] = linfo.errorf.get('INITIAL', None) if s not in linfo.ignore: linfo.ignore[s] = linfo.ignore.get('INITIAL', '') # Create global versions of the token() and input() functions token = lexobj.token input = lexobj.input lexer = lexobj # If in optimize mode, we write the lextab if lextab and optimize: if outputdir is None: # If no output directory is set, the location of the output files # is determined according to the following rules: # - If lextab specifies a package, files go into that package directory # - Otherwise, files go in the same directory as the specifying module if isinstance(lextab, types.ModuleType): srcfile = lextab.__file__ else: if '.' not in lextab: srcfile = ldict['__file__'] else: parts = lextab.split('.') pkgname = '.'.join(parts[:-1]) exec('import %s' % pkgname) srcfile = getattr(sys.modules[pkgname], '__file__', '') outputdir = os.path.dirname(srcfile) try: lexobj.writetab(lextab, outputdir) except IOError as e: errorlog.warning("Couldn't write lextab module %r. %s" % (lextab, e)) return lexobj # ----------------------------------------------------------------------------- # runmain() # # This runs the lexer as a main program # ----------------------------------------------------------------------------- def runmain(lexer=None, data=None): if not data: try: filename = sys.argv[1] f = open(filename) data = f.read() f.close() except IndexError: sys.stdout.write('Reading from standard input (type EOF to end):\n') data = sys.stdin.read() if lexer: _input = lexer.input else: _input = input _input(data) if lexer: _token = lexer.token else: _token = token while True: tok = _token() if not tok: break sys.stdout.write('(%s,%r,%d,%d)\n' % (tok.type, tok.value, tok.lineno, tok.lexpos)) # ----------------------------------------------------------------------------- # @TOKEN(regex) # # This decorator function can be used to set the regex expression on a function # when its docstring might need to be set in an alternative way # ----------------------------------------------------------------------------- def TOKEN(r): def set_regex(f): if hasattr(r, '__call__'): f.regex = _get_regex(r) else: f.regex = r return f return set_regex # Alternative spelling of the TOKEN decorator Token = TOKEN
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