Add PLY (Python Lex Yacc)

third_party/ply/lex.py

+# -----------------------------------------------------------------------------
+# ply: lex.py
+#
+# Copyright (C) 2001-2011,
+# 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__    = "3.4"
+__tabversion__ = "3.2"       # Version of table file used
+
+import re, sys, types, copy, os
+
+# This tuple contains known string types
+try:
+    # Python 2.6
+    StringTypes = (types.StringType, types.UnicodeType)
+except AttributeError:
+    # Python 3.0
+    StringTypes = (str, bytes)
+
+# Extract the code attribute of a function. Different implementations
+# are for Python 2/3 compatibility.
+
+if sys.version_info[0] < 3:
+    def func_code(f):
+        return f.func_code
+else:
+    def func_code(f):
+        return f.__code__
+
+# 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.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.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 = 0          # 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,tabfile,outputdir=""):
+        if isinstance(tabfile,types.ModuleType):
+            return
+        basetabfilename = tabfile.split(".")[-1]
+        filename = os.path.join(outputdir,basetabfilename)+".py"
+        tf = open(filename,"w")
+        tf.write("# %s.py. This file automatically created by PLY (version %s). Don't edit!\n" % (tabfile,__version__))
+        tf.write("_tabversion   = %s\n" % repr(__version__))
+        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))
+
+        tabre = { }
+        # Collect all functions in the initial state
+        initial = self.lexstatere["INITIAL"]
+        initialfuncs = []
+        for part in initial:
+            for f in part[1]:
+                if f and f[0]:
+                    initialfuncs.append(f)
+
+        for key, lre in self.lexstatere.items():
+             titem = []
+             for i in range(len(lre)):
+                  titem.append((self.lexstateretext[key][i],_funcs_to_names(lre[i][1],self.lexstaterenames[key][i])))
+             tabre[key] = titem
+
+        tf.write("_lexstatere   = %s\n" % repr(tabre))
+        tf.write("_lexstateignore = %s\n" % repr(self.lexstateignore))
+
+        taberr = { }
+        for key, ef in self.lexstateerrorf.items():
+             if ef:
+                  taberr[key] = ef.__name__
+             else:
+                  taberr[key] = None
+        tf.write("_lexstateerrorf = %s\n" % repr(taberr))
+        tf.close()
+
+    # ------------------------------------------------------------
+    # readtab() - Read lexer information from a tab file
+    # ------------------------------------------------------------
+    def readtab(self,tabfile,fdict):
+        if isinstance(tabfile,types.ModuleType):
+            lextab = tabfile
+        else:
+            if sys.version_info[0] < 3:
+                exec("import %s as lextab" % tabfile)
+            else:
+                env = { }
+                exec("import %s as lextab" % tabfile, env,env)
+                lextab = env['lextab']
+
+        if getattr(lextab,"_tabversion","0.0") != __version__:
+            raise ImportError("Inconsistent PLY version")
+
+        self.lextokens      = lextab._lextokens
+        self.lexreflags     = lextab._lexreflags
+        self.lexliterals    = lextab._lexliterals
+        self.lexstateinfo   = lextab._lexstateinfo
+        self.lexstateignore = lextab._lexstateignore
+        self.lexstatere     = { }
+        self.lexstateretext = { }
+        for key,lre in lextab._lexstatere.items():
+             titem = []
+             txtitem = []
+             for i in range(len(lre)):
+                  titem.append((re.compile(lre[i][0],lextab._lexreflags | re.VERBOSE),_names_to_funcs(lre[i][1],fdict)))
+                  txtitem.append(lre[i][0])
+             self.lexstatere[key] = titem
+             self.lexstateretext[key] = txtitem
+        self.lexstateerrorf = { }
+        for key,ef in lextab._lexstateerrorf.items():
+             self.lexstateerrorf[key] = 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 not state 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.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 not newtok.type in self.lextokens:
+                        raise LexError("%s:%d: Rule '%s' returned an unknown token type '%s'" % (
+                            func_code(func).co_filename, func_code(func).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:])
+
+        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_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):
+    try:
+        raise RuntimeError
+    except RuntimeError:
+        e,b,t = sys.exc_info()
+        f = t.tb_frame
+        while levels > 0:
+            f = f.f_back                   
+            levels -= 1
+        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 in range(1,len(parts)):
+         if not parts[i] in names and parts[i] != '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.files      = {}
+        self.error      = 0
+
+        if log is None:
+            self.log = PlyLogger(sys.stderr)
+        else:
+            self.log = 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 = 1
+            return
+
+        if not isinstance(tokens,(list, tuple)):
+            self.log.error("tokens must be a list or tuple")
+            self.error = 1
+            return
+        
+        if not tokens:
+            self.log.error("tokens is empty")
+            self.error = 1
+            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 = 1
+            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","")
+
+    # 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 = 1
+                    continue
+
+        except TypeError:
+            self.log.error("Invalid literals specification. literals must be a sequence of characters")
+            self.error = 1
+
+    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 = 1
+             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 = 1
+                               continue
+                        name, statetype = s
+                        if not isinstance(name,StringTypes):
+                               self.log.error("State name %s must be a string", repr(name))
+                               self.error = 1
+                               continue
+                        if not (statetype == 'inclusive' or statetype == 'exclusive'):
+                               self.log.error("State type for state %s must be 'inclusive' or 'exclusive'",name)
+                               self.error = 1
+                               continue
+                        if name in self.stateinfo:
+                               self.log.error("State '%s' already defined",name)
+                               self.error = 1
+                               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
+
+        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 = 1
+            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 == 'ignore':
+                    line = func_code(t).co_firstlineno
+                    file = func_code(t).co_filename
+                    self.log.error("%s:%d: Rule '%s' must be defined as a string",file,line,t.__name__)
+                    self.error = 1
+                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 = 1
+                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 = 1
+
+        # Sort the functions by line number
+        for f in self.funcsym.values():
+            if sys.version_info[0] < 3:
+                f.sort(lambda x,y: cmp(func_code(x[1]).co_firstlineno,func_code(y[1]).co_firstlineno))
+            else:
+                # Python 3.0
+                f.sort(key=lambda x: func_code(x[1]).co_firstlineno)
+
+        # Sort the strings by regular expression length
+        for s in self.strsym.values():
+            if sys.version_info[0] < 3:
+                s.sort(lambda x,y: (len(x[1]) < len(y[1])) - (len(x[1]) > len(y[1])))
+            else:
+                # Python 3.0
+                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 = func_code(f).co_firstlineno
+                file = func_code(f).co_filename
+                self.files[file] = 1
+
+                tokname = self.toknames[fname]
+                if isinstance(f, types.MethodType):
+                    reqargs = 2
+                else:
+                    reqargs = 1
+                nargs = func_code(f).co_argcount
+                if nargs > reqargs:
+                    self.log.error("%s:%d: Rule '%s' has too many arguments",file,line,f.__name__)
+                    self.error = 1
+                    continue
+
+                if nargs < reqargs:
+                    self.log.error("%s:%d: Rule '%s' requires an argument", file,line,f.__name__)
+                    self.error = 1
+                    continue
+
+                if not f.__doc__:
+                    self.log.error("%s:%d: No regular expression defined for rule '%s'",file,line,f.__name__)
+                    self.error = 1
+                    continue
+
+                try:
+                    c = re.compile("(?P<%s>%s)" % (fname,f.__doc__), 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 = 1
+                except re.error:
+                    _etype, e, _etrace = sys.exc_info()
+                    self.log.error("%s:%d: Invalid regular expression for rule '%s'. %s", file,line,f.__name__,e)
+                    if '#' in f.__doc__:
+                        self.log.error("%s:%d. Make sure '#' in rule '%s' is escaped with '\\#'",file,line, f.__name__)
+                    self.error = 1
+
+            # 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 = 1
+                    continue
+
+                if not tokname in self.tokens and tokname.find("ignore_") < 0:
+                    self.log.error("Rule '%s' defined for an unspecified token %s",name,tokname)
+                    self.error = 1
+                    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 = 1
+                except re.error:
+                    _etype, e, _etrace = sys.exc_info()
+                    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 = 1
+
+            if not self.funcsym[state] and not self.strsym[state]:
+                self.log.error("No rules defined for state '%s'",state)
+                self.error = 1
+
+            # Validate the error function
+            efunc = self.errorf.get(state,None)
+            if efunc:
+                f = efunc
+                line = func_code(f).co_firstlineno
+                file = func_code(f).co_filename
+                self.files[file] = 1
+
+                if isinstance(f, types.MethodType):
+                    reqargs = 2
+                else:
+                    reqargs = 1
+                nargs = func_code(f).co_argcount
+                if nargs > reqargs:
+                    self.log.error("%s:%d: Rule '%s' has too many arguments",file,line,f.__name__)
+                    self.error = 1
+
+                if nargs < reqargs:
+                    self.log.error("%s:%d: Rule '%s' requires an argument", file,line,f.__name__)
+                    self.error = 1
+
+        for f in self.files:
+            self.validate_file(f)
+
+
+    # -----------------------------------------------------------------------------
+    # validate_file()
+    #
+    # 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 given file.  
+    # -----------------------------------------------------------------------------
+
+    def validate_file(self,filename):
+        import os.path
+        base,ext = os.path.splitext(filename)
+        if ext != '.py': return         # No idea what the file is. Return OK
+
+        try:
+            f = open(filename)
+            lines = f.readlines()
+            f.close()
+        except IOError:
+            return                      # Couldn't find the file.  Don't worry about it
+
+        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 l in lines:
+            m = fre.match(l)
+            if not m:
+                m = sre.match(l)
+            if m:
+                name = m.group(1)
+                prev = counthash.get(name)
+                if not prev:
+                    counthash[name] = linen
+                else:
+                    self.log.error("%s:%d: Rule %s redefined. Previously defined on line %d",filename,linen,name,prev)
+                    self.error = 1
+            linen += 1
+            
+# -----------------------------------------------------------------------------
+# lex(module)
+#
+# Build all of the regular expression rules from definitions in the supplied module
+# -----------------------------------------------------------------------------
+def lex(module=None,object=None,debug=0,optimize=0,lextab="lextab",reflags=0,nowarn=0,outputdir="", debuglog=None, errorlog=None):
+    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
+
+    if module:
+        _items = [(k,getattr(module,k)) for k in dir(module)]
+        ldict = dict(_items)
+    else:
+        ldict = get_caller_module_dict(2)
+
+    # 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 = { }
+    for n in linfo.tokens:
+        lexobj.lextokens[n] = 1
+
+    # Get literals specification
+    if isinstance(linfo.literals,(list,tuple)):
+        lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals)
+    else:
+        lexobj.lexliterals = linfo.literals
+
+    # 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 = func_code(f).co_firstlineno
+            file = func_code(f).co_filename
+            regex_list.append("(?P<%s>%s)" % (fname,f.__doc__))
+            if debug:
+                debuglog.info("lex: Adding rule %s -> '%s' (state '%s')",fname,f.__doc__, 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 in range(len(re_text)):
+                debuglog.info("lex: state '%s' : regex[%d] = '%s'",state, i, re_text[i])
+
+    # 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")
+
+    # Check state information for ignore and error rules
+    for s,stype in stateinfo.items():
+        if stype == 'exclusive':
+              if not s in linfo.errorf:
+                   errorlog.warning("No error rule is defined for exclusive state '%s'", s)
+              if not s in linfo.ignore and lexobj.lexignore:
+                   errorlog.warning("No ignore rule is defined for exclusive state '%s'", s)
+        elif stype == 'inclusive':
+              if not s in linfo.errorf:
+                   linfo.errorf[s] = linfo.errorf.get("INITIAL",None)
+              if not s 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:
+        lexobj.writetab(lextab,outputdir)
+
+    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 1:
+        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_doc(f):
+        if hasattr(r,"__call__"):
+            f.__doc__ = r.__doc__
+        else:
+            f.__doc__ = r
+        return f
+    return set_doc
+
+# Alternative spelling of the TOKEN decorator
+Token = TOKEN
+