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<oerjan> learn Dragons are fractal creatures of magic, capable of shrinking or expanding to any size. Taneb invented them to live inside his string diagrams, but they prefer to hover around pinheads and feed on angels.
author | HackBot |
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date | Wed, 02 Nov 2016 23:36:25 +0000 |
parents | 343ff337a19b |
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# ----------------------------------------------------------------------------- # ply: lex.py # # Copyright (C) 2001-2015, # 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__ = '3.8' __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 = %s\n' % repr(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): lines, linen = inspect.getsourcelines(module) 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