Initial import
diff --git a/README.md b/README.md
index a69ae4a..6144427 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,16 @@
-plyprotobuf
-===========
+# PLY Protobuf
 
 Protocol Buffers lexer & parser for PLY
+
+## Information
+* ply/ subdirectory is present in this repo just for demonstration purposes only. If you intend to use this, prefer better original
+ PLY repository which is up-to-date.
+* This is my first PLY / parser generator project, there may be bugs although it works for me for quite complicated protocol buffers files. 
+If you find a bug, please feel free to submit a pull request or file an issue.
+* This work was inspired by:
+  * [plyj] [1], Java lexer & parser for PLY.
+  * [pyparsing] [2], Protocol Buffers parsing example. 
+ 
+ 
+ [1]: https://github.com/musiKk/plyj
+ [2]: http://pyparsing.wikispaces.com/
\ No newline at end of file
diff --git a/demo.py b/demo.py
new file mode 100644
index 0000000..aea75a2
--- /dev/null
+++ b/demo.py
@@ -0,0 +1,47 @@
+import plyproto.parser as plyproto
+
+test1 = """package tutorial;"""
+
+test2 = """package tutorial;
+
+message Person {
+  required string name = 1;
+  required int32 id = 2;
+  optional string email = 3;
+}
+
+"""
+
+test3 = """package tutorial;
+option java_outer_classname = "PushNotifications";
+option optimize_for = "SPEED";
+
+  message Person {
+      required string name = 1;
+      required int32 id = 2;
+      optional string email = 3;
+
+      enum PhoneType {
+        MOBILE = 0;
+        HOME = 1;
+        WORK = 2;
+      }
+
+      message PhoneNumber {
+        required string number = 1;
+        optional PhoneType type = 2 [default = HOME];
+      }
+
+      repeated PhoneNumber phone = 4;
+      extensions 500 to 990;
+}
+
+message AddressBook {
+  repeated Person person = 1;
+
+  // Possible extension numbers.
+  extensions 500 to max;
+}"""
+
+parser = plyproto.ProtobufAnalyzer()
+print(parser.parse_string(test3))
diff --git a/ply/__init__.py b/ply/__init__.py
new file mode 100644
index 0000000..853a985
--- /dev/null
+++ b/ply/__init__.py
@@ -0,0 +1,4 @@
+# PLY package
+# Author: David Beazley (dave@dabeaz.com)
+
+__all__ = ['lex','yacc']
diff --git a/ply/cpp.py b/ply/cpp.py
new file mode 100644
index 0000000..2f6a030
--- /dev/null
+++ b/ply/cpp.py
@@ -0,0 +1,908 @@
+# -----------------------------------------------------------------------------
+# cpp.py
+#
+# Author:  David Beazley (http://www.dabeaz.com)
+# Copyright (C) 2007
+# All rights reserved
+#
+# This module implements an ANSI-C style lexical preprocessor for PLY. 
+# -----------------------------------------------------------------------------
+from __future__ import generators
+
+# -----------------------------------------------------------------------------
+# Default preprocessor lexer definitions.   These tokens are enough to get
+# a basic preprocessor working.   Other modules may import these if they want
+# -----------------------------------------------------------------------------
+
+tokens = (
+   'CPP_ID','CPP_INTEGER', 'CPP_FLOAT', 'CPP_STRING', 'CPP_CHAR', 'CPP_WS', 'CPP_COMMENT1', 'CPP_COMMENT2', 'CPP_POUND','CPP_DPOUND'
+)
+
+literals = "+-*/%|&~^<>=!?()[]{}.,;:\\\'\""
+
+# Whitespace
+def t_CPP_WS(t):
+    r'\s+'
+    t.lexer.lineno += t.value.count("\n")
+    return t
+
+t_CPP_POUND = r'\#'
+t_CPP_DPOUND = r'\#\#'
+
+# Identifier
+t_CPP_ID = r'[A-Za-z_][\w_]*'
+
+# Integer literal
+def CPP_INTEGER(t):
+    r'(((((0x)|(0X))[0-9a-fA-F]+)|(\d+))([uU][lL]|[lL][uU]|[uU]|[lL])?)'
+    return t
+
+t_CPP_INTEGER = CPP_INTEGER
+
+# Floating literal
+t_CPP_FLOAT = r'((\d+)(\.\d+)(e(\+|-)?(\d+))? | (\d+)e(\+|-)?(\d+))([lL]|[fF])?'
+
+# String literal
+def t_CPP_STRING(t):
+    r'\"([^\\\n]|(\\(.|\n)))*?\"'
+    t.lexer.lineno += t.value.count("\n")
+    return t
+
+# Character constant 'c' or L'c'
+def t_CPP_CHAR(t):
+    r'(L)?\'([^\\\n]|(\\(.|\n)))*?\''
+    t.lexer.lineno += t.value.count("\n")
+    return t
+
+# Comment
+def t_CPP_COMMENT1(t):
+    r'(/\*(.|\n)*?\*/)'
+    ncr = t.value.count("\n")
+    t.lexer.lineno += ncr
+    # replace with one space or a number of '\n'
+    t.type = 'CPP_WS'; t.value = '\n' * ncr if ncr else ' '
+    return t
+
+# Line comment
+def t_CPP_COMMENT2(t):
+    r'(//.*?(\n|$))'
+    # replace with '/n'
+    t.type = 'CPP_WS'; t.value = '\n'
+    
+def t_error(t):
+    t.type = t.value[0]
+    t.value = t.value[0]
+    t.lexer.skip(1)
+    return t
+
+import re
+import copy
+import time
+import os.path
+
+# -----------------------------------------------------------------------------
+# trigraph()
+# 
+# Given an input string, this function replaces all trigraph sequences. 
+# The following mapping is used:
+#
+#     ??=    #
+#     ??/    \
+#     ??'    ^
+#     ??(    [
+#     ??)    ]
+#     ??!    |
+#     ??<    {
+#     ??>    }
+#     ??-    ~
+# -----------------------------------------------------------------------------
+
+_trigraph_pat = re.compile(r'''\?\?[=/\'\(\)\!<>\-]''')
+_trigraph_rep = {
+    '=':'#',
+    '/':'\\',
+    "'":'^',
+    '(':'[',
+    ')':']',
+    '!':'|',
+    '<':'{',
+    '>':'}',
+    '-':'~'
+}
+
+def trigraph(input):
+    return _trigraph_pat.sub(lambda g: _trigraph_rep[g.group()[-1]],input)
+
+# ------------------------------------------------------------------
+# Macro object
+#
+# This object holds information about preprocessor macros
+#
+#    .name      - Macro name (string)
+#    .value     - Macro value (a list of tokens)
+#    .arglist   - List of argument names
+#    .variadic  - Boolean indicating whether or not variadic macro
+#    .vararg    - Name of the variadic parameter
+#
+# When a macro is created, the macro replacement token sequence is
+# pre-scanned and used to create patch lists that are later used
+# during macro expansion
+# ------------------------------------------------------------------
+
+class Macro(object):
+    def __init__(self,name,value,arglist=None,variadic=False):
+        self.name = name
+        self.value = value
+        self.arglist = arglist
+        self.variadic = variadic
+        if variadic:
+            self.vararg = arglist[-1]
+        self.source = None
+
+# ------------------------------------------------------------------
+# Preprocessor object
+#
+# Object representing a preprocessor.  Contains macro definitions,
+# include directories, and other information
+# ------------------------------------------------------------------
+
+class Preprocessor(object):
+    def __init__(self,lexer=None):
+        if lexer is None:
+            lexer = lex.lexer
+        self.lexer = lexer
+        self.macros = { }
+        self.path = []
+        self.temp_path = []
+
+        # Probe the lexer for selected tokens
+        self.lexprobe()
+
+        tm = time.localtime()
+        self.define("__DATE__ \"%s\"" % time.strftime("%b %d %Y",tm))
+        self.define("__TIME__ \"%s\"" % time.strftime("%H:%M:%S",tm))
+        self.parser = None
+
+    # -----------------------------------------------------------------------------
+    # tokenize()
+    #
+    # Utility function. Given a string of text, tokenize into a list of tokens
+    # -----------------------------------------------------------------------------
+
+    def tokenize(self,text):
+        tokens = []
+        self.lexer.input(text)
+        while True:
+            tok = self.lexer.token()
+            if not tok: break
+            tokens.append(tok)
+        return tokens
+
+    # ---------------------------------------------------------------------
+    # error()
+    #
+    # Report a preprocessor error/warning of some kind
+    # ----------------------------------------------------------------------
+
+    def error(self,file,line,msg):
+        print("%s:%d %s" % (file,line,msg))
+
+    # ----------------------------------------------------------------------
+    # lexprobe()
+    #
+    # This method probes the preprocessor lexer object to discover
+    # the token types of symbols that are important to the preprocessor.
+    # If this works right, the preprocessor will simply "work"
+    # with any suitable lexer regardless of how tokens have been named.
+    # ----------------------------------------------------------------------
+
+    def lexprobe(self):
+
+        # Determine the token type for identifiers
+        self.lexer.input("identifier")
+        tok = self.lexer.token()
+        if not tok or tok.value != "identifier":
+            print("Couldn't determine identifier type")
+        else:
+            self.t_ID = tok.type
+
+        # Determine the token type for integers
+        self.lexer.input("12345")
+        tok = self.lexer.token()
+        if not tok or int(tok.value) != 12345:
+            print("Couldn't determine integer type")
+        else:
+            self.t_INTEGER = tok.type
+            self.t_INTEGER_TYPE = type(tok.value)
+
+        # Determine the token type for strings enclosed in double quotes
+        self.lexer.input("\"filename\"")
+        tok = self.lexer.token()
+        if not tok or tok.value != "\"filename\"":
+            print("Couldn't determine string type")
+        else:
+            self.t_STRING = tok.type
+
+        # Determine the token type for whitespace--if any
+        self.lexer.input("  ")
+        tok = self.lexer.token()
+        if not tok or tok.value != "  ":
+            self.t_SPACE = None
+        else:
+            self.t_SPACE = tok.type
+
+        # Determine the token type for newlines
+        self.lexer.input("\n")
+        tok = self.lexer.token()
+        if not tok or tok.value != "\n":
+            self.t_NEWLINE = None
+            print("Couldn't determine token for newlines")
+        else:
+            self.t_NEWLINE = tok.type
+
+        self.t_WS = (self.t_SPACE, self.t_NEWLINE)
+
+        # Check for other characters used by the preprocessor
+        chars = [ '<','>','#','##','\\','(',')',',','.']
+        for c in chars:
+            self.lexer.input(c)
+            tok = self.lexer.token()
+            if not tok or tok.value != c:
+                print("Unable to lex '%s' required for preprocessor" % c)
+
+    # ----------------------------------------------------------------------
+    # add_path()
+    #
+    # Adds a search path to the preprocessor.  
+    # ----------------------------------------------------------------------
+
+    def add_path(self,path):
+        self.path.append(path)
+
+    # ----------------------------------------------------------------------
+    # group_lines()
+    #
+    # Given an input string, this function splits it into lines.  Trailing whitespace
+    # is removed.   Any line ending with \ is grouped with the next line.  This
+    # function forms the lowest level of the preprocessor---grouping into text into
+    # a line-by-line format.
+    # ----------------------------------------------------------------------
+
+    def group_lines(self,input):
+        lex = self.lexer.clone()
+        lines = [x.rstrip() for x in input.splitlines()]
+        for i in xrange(len(lines)):
+            j = i+1
+            while lines[i].endswith('\\') and (j < len(lines)):
+                lines[i] = lines[i][:-1]+lines[j]
+                lines[j] = ""
+                j += 1
+
+        input = "\n".join(lines)
+        lex.input(input)
+        lex.lineno = 1
+
+        current_line = []
+        while True:
+            tok = lex.token()
+            if not tok:
+                break
+            current_line.append(tok)
+            if tok.type in self.t_WS and '\n' in tok.value:
+                yield current_line
+                current_line = []
+
+        if current_line:
+            yield current_line
+
+    # ----------------------------------------------------------------------
+    # tokenstrip()
+    # 
+    # Remove leading/trailing whitespace tokens from a token list
+    # ----------------------------------------------------------------------
+
+    def tokenstrip(self,tokens):
+        i = 0
+        while i < len(tokens) and tokens[i].type in self.t_WS:
+            i += 1
+        del tokens[:i]
+        i = len(tokens)-1
+        while i >= 0 and tokens[i].type in self.t_WS:
+            i -= 1
+        del tokens[i+1:]
+        return tokens
+
+
+    # ----------------------------------------------------------------------
+    # collect_args()
+    #
+    # Collects comma separated arguments from a list of tokens.   The arguments
+    # must be enclosed in parenthesis.  Returns a tuple (tokencount,args,positions)
+    # where tokencount is the number of tokens consumed, args is a list of arguments,
+    # and positions is a list of integers containing the starting index of each
+    # argument.  Each argument is represented by a list of tokens.
+    #
+    # When collecting arguments, leading and trailing whitespace is removed
+    # from each argument.  
+    #
+    # This function properly handles nested parenthesis and commas---these do not
+    # define new arguments.
+    # ----------------------------------------------------------------------
+
+    def collect_args(self,tokenlist):
+        args = []
+        positions = []
+        current_arg = []
+        nesting = 1
+        tokenlen = len(tokenlist)
+    
+        # Search for the opening '('.
+        i = 0
+        while (i < tokenlen) and (tokenlist[i].type in self.t_WS):
+            i += 1
+
+        if (i < tokenlen) and (tokenlist[i].value == '('):
+            positions.append(i+1)
+        else:
+            self.error(self.source,tokenlist[0].lineno,"Missing '(' in macro arguments")
+            return 0, [], []
+
+        i += 1
+
+        while i < tokenlen:
+            t = tokenlist[i]
+            if t.value == '(':
+                current_arg.append(t)
+                nesting += 1
+            elif t.value == ')':
+                nesting -= 1
+                if nesting == 0:
+                    if current_arg:
+                        args.append(self.tokenstrip(current_arg))
+                        positions.append(i)
+                    return i+1,args,positions
+                current_arg.append(t)
+            elif t.value == ',' and nesting == 1:
+                args.append(self.tokenstrip(current_arg))
+                positions.append(i+1)
+                current_arg = []
+            else:
+                current_arg.append(t)
+            i += 1
+    
+        # Missing end argument
+        self.error(self.source,tokenlist[-1].lineno,"Missing ')' in macro arguments")
+        return 0, [],[]
+
+    # ----------------------------------------------------------------------
+    # macro_prescan()
+    #
+    # Examine the macro value (token sequence) and identify patch points
+    # This is used to speed up macro expansion later on---we'll know
+    # right away where to apply patches to the value to form the expansion
+    # ----------------------------------------------------------------------
+    
+    def macro_prescan(self,macro):
+        macro.patch     = []             # Standard macro arguments 
+        macro.str_patch = []             # String conversion expansion
+        macro.var_comma_patch = []       # Variadic macro comma patch
+        i = 0
+        while i < len(macro.value):
+            if macro.value[i].type == self.t_ID and macro.value[i].value in macro.arglist:
+                argnum = macro.arglist.index(macro.value[i].value)
+                # Conversion of argument to a string
+                if i > 0 and macro.value[i-1].value == '#':
+                    macro.value[i] = copy.copy(macro.value[i])
+                    macro.value[i].type = self.t_STRING
+                    del macro.value[i-1]
+                    macro.str_patch.append((argnum,i-1))
+                    continue
+                # Concatenation
+                elif (i > 0 and macro.value[i-1].value == '##'):
+                    macro.patch.append(('c',argnum,i-1))
+                    del macro.value[i-1]
+                    continue
+                elif ((i+1) < len(macro.value) and macro.value[i+1].value == '##'):
+                    macro.patch.append(('c',argnum,i))
+                    i += 1
+                    continue
+                # Standard expansion
+                else:
+                    macro.patch.append(('e',argnum,i))
+            elif macro.value[i].value == '##':
+                if macro.variadic and (i > 0) and (macro.value[i-1].value == ',') and \
+                        ((i+1) < len(macro.value)) and (macro.value[i+1].type == self.t_ID) and \
+                        (macro.value[i+1].value == macro.vararg):
+                    macro.var_comma_patch.append(i-1)
+            i += 1
+        macro.patch.sort(key=lambda x: x[2],reverse=True)
+
+    # ----------------------------------------------------------------------
+    # macro_expand_args()
+    #
+    # Given a Macro and list of arguments (each a token list), this method
+    # returns an expanded version of a macro.  The return value is a token sequence
+    # representing the replacement macro tokens
+    # ----------------------------------------------------------------------
+
+    def macro_expand_args(self,macro,args):
+        # Make a copy of the macro token sequence
+        rep = [copy.copy(_x) for _x in macro.value]
+
+        # Make string expansion patches.  These do not alter the length of the replacement sequence
+        
+        str_expansion = {}
+        for argnum, i in macro.str_patch:
+            if argnum not in str_expansion:
+                str_expansion[argnum] = ('"%s"' % "".join([x.value for x in args[argnum]])).replace("\\","\\\\")
+            rep[i] = copy.copy(rep[i])
+            rep[i].value = str_expansion[argnum]
+
+        # Make the variadic macro comma patch.  If the variadic macro argument is empty, we get rid
+        comma_patch = False
+        if macro.variadic and not args[-1]:
+            for i in macro.var_comma_patch:
+                rep[i] = None
+                comma_patch = True
+
+        # Make all other patches.   The order of these matters.  It is assumed that the patch list
+        # has been sorted in reverse order of patch location since replacements will cause the
+        # size of the replacement sequence to expand from the patch point.
+        
+        expanded = { }
+        for ptype, argnum, i in macro.patch:
+            # Concatenation.   Argument is left unexpanded
+            if ptype == 'c':
+                rep[i:i+1] = args[argnum]
+            # Normal expansion.  Argument is macro expanded first
+            elif ptype == 'e':
+                if argnum not in expanded:
+                    expanded[argnum] = self.expand_macros(args[argnum])
+                rep[i:i+1] = expanded[argnum]
+
+        # Get rid of removed comma if necessary
+        if comma_patch:
+            rep = [_i for _i in rep if _i]
+
+        return rep
+
+
+    # ----------------------------------------------------------------------
+    # expand_macros()
+    #
+    # Given a list of tokens, this function performs macro expansion.
+    # The expanded argument is a dictionary that contains macros already
+    # expanded.  This is used to prevent infinite recursion.
+    # ----------------------------------------------------------------------
+
+    def expand_macros(self,tokens,expanded=None):
+        if expanded is None:
+            expanded = {}
+        i = 0
+        while i < len(tokens):
+            t = tokens[i]
+            if t.type == self.t_ID:
+                if t.value in self.macros and t.value not in expanded:
+                    # Yes, we found a macro match
+                    expanded[t.value] = True
+                    
+                    m = self.macros[t.value]
+                    if not m.arglist:
+                        # A simple macro
+                        ex = self.expand_macros([copy.copy(_x) for _x in m.value],expanded)
+                        for e in ex:
+                            e.lineno = t.lineno
+                        tokens[i:i+1] = ex
+                        i += len(ex)
+                    else:
+                        # A macro with arguments
+                        j = i + 1
+                        while j < len(tokens) and tokens[j].type in self.t_WS:
+                            j += 1
+                        if tokens[j].value == '(':
+                            tokcount,args,positions = self.collect_args(tokens[j:])
+                            if not m.variadic and len(args) !=  len(m.arglist):
+                                self.error(self.source,t.lineno,"Macro %s requires %d arguments" % (t.value,len(m.arglist)))
+                                i = j + tokcount
+                            elif m.variadic and len(args) < len(m.arglist)-1:
+                                if len(m.arglist) > 2:
+                                    self.error(self.source,t.lineno,"Macro %s must have at least %d arguments" % (t.value, len(m.arglist)-1))
+                                else:
+                                    self.error(self.source,t.lineno,"Macro %s must have at least %d argument" % (t.value, len(m.arglist)-1))
+                                i = j + tokcount
+                            else:
+                                if m.variadic:
+                                    if len(args) == len(m.arglist)-1:
+                                        args.append([])
+                                    else:
+                                        args[len(m.arglist)-1] = tokens[j+positions[len(m.arglist)-1]:j+tokcount-1]
+                                        del args[len(m.arglist):]
+                                        
+                                # Get macro replacement text
+                                rep = self.macro_expand_args(m,args)
+                                rep = self.expand_macros(rep,expanded)
+                                for r in rep:
+                                    r.lineno = t.lineno
+                                tokens[i:j+tokcount] = rep
+                                i += len(rep)
+                    del expanded[t.value]
+                    continue
+                elif t.value == '__LINE__':
+                    t.type = self.t_INTEGER
+                    t.value = self.t_INTEGER_TYPE(t.lineno)
+                
+            i += 1
+        return tokens
+
+    # ----------------------------------------------------------------------    
+    # evalexpr()
+    # 
+    # Evaluate an expression token sequence for the purposes of evaluating
+    # integral expressions.
+    # ----------------------------------------------------------------------
+
+    def evalexpr(self,tokens):
+        # tokens = tokenize(line)
+        # Search for defined macros
+        i = 0
+        while i < len(tokens):
+            if tokens[i].type == self.t_ID and tokens[i].value == 'defined':
+                j = i + 1
+                needparen = False
+                result = "0L"
+                while j < len(tokens):
+                    if tokens[j].type in self.t_WS:
+                        j += 1
+                        continue
+                    elif tokens[j].type == self.t_ID:
+                        if tokens[j].value in self.macros:
+                            result = "1L"
+                        else:
+                            result = "0L"
+                        if not needparen: break
+                    elif tokens[j].value == '(':
+                        needparen = True
+                    elif tokens[j].value == ')':
+                        break
+                    else:
+                        self.error(self.source,tokens[i].lineno,"Malformed defined()")
+                    j += 1
+                tokens[i].type = self.t_INTEGER
+                tokens[i].value = self.t_INTEGER_TYPE(result)
+                del tokens[i+1:j+1]
+            i += 1
+        tokens = self.expand_macros(tokens)
+        for i,t in enumerate(tokens):
+            if t.type == self.t_ID:
+                tokens[i] = copy.copy(t)
+                tokens[i].type = self.t_INTEGER
+                tokens[i].value = self.t_INTEGER_TYPE("0L")
+            elif t.type == self.t_INTEGER:
+                tokens[i] = copy.copy(t)
+                # Strip off any trailing suffixes
+                tokens[i].value = str(tokens[i].value)
+                while tokens[i].value[-1] not in "0123456789abcdefABCDEF":
+                    tokens[i].value = tokens[i].value[:-1]
+        
+        expr = "".join([str(x.value) for x in tokens])
+        expr = expr.replace("&&"," and ")
+        expr = expr.replace("||"," or ")
+        expr = expr.replace("!"," not ")
+        try:
+            result = eval(expr)
+        except StandardError:
+            self.error(self.source,tokens[0].lineno,"Couldn't evaluate expression")
+            result = 0
+        return result
+
+    # ----------------------------------------------------------------------
+    # parsegen()
+    #
+    # Parse an input string/
+    # ----------------------------------------------------------------------
+    def parsegen(self,input,source=None):
+
+        # Replace trigraph sequences
+        t = trigraph(input)
+        lines = self.group_lines(t)
+
+        if not source:
+            source = ""
+            
+        self.define("__FILE__ \"%s\"" % source)
+
+        self.source = source
+        chunk = []
+        enable = True
+        iftrigger = False
+        ifstack = []
+
+        for x in lines:
+            for i,tok in enumerate(x):
+                if tok.type not in self.t_WS: break
+            if tok.value == '#':
+                # Preprocessor directive
+
+                # insert necessary whitespace instead of eaten tokens
+                for tok in x:
+                    if tok.type in self.t_WS and '\n' in tok.value:
+                        chunk.append(tok)
+                
+                dirtokens = self.tokenstrip(x[i+1:])
+                if dirtokens:
+                    name = dirtokens[0].value
+                    args = self.tokenstrip(dirtokens[1:])
+                else:
+                    name = ""
+                    args = []
+                
+                if name == 'define':
+                    if enable:
+                        for tok in self.expand_macros(chunk):
+                            yield tok
+                        chunk = []
+                        self.define(args)
+                elif name == 'include':
+                    if enable:
+                        for tok in self.expand_macros(chunk):
+                            yield tok
+                        chunk = []
+                        oldfile = self.macros['__FILE__']
+                        for tok in self.include(args):
+                            yield tok
+                        self.macros['__FILE__'] = oldfile
+                        self.source = source
+                elif name == 'undef':
+                    if enable:
+                        for tok in self.expand_macros(chunk):
+                            yield tok
+                        chunk = []
+                        self.undef(args)
+                elif name == 'ifdef':
+                    ifstack.append((enable,iftrigger))
+                    if enable:
+                        if not args[0].value in self.macros:
+                            enable = False
+                            iftrigger = False
+                        else:
+                            iftrigger = True
+                elif name == 'ifndef':
+                    ifstack.append((enable,iftrigger))
+                    if enable:
+                        if args[0].value in self.macros:
+                            enable = False
+                            iftrigger = False
+                        else:
+                            iftrigger = True
+                elif name == 'if':
+                    ifstack.append((enable,iftrigger))
+                    if enable:
+                        result = self.evalexpr(args)
+                        if not result:
+                            enable = False
+                            iftrigger = False
+                        else:
+                            iftrigger = True
+                elif name == 'elif':
+                    if ifstack:
+                        if ifstack[-1][0]:     # We only pay attention if outer "if" allows this
+                            if enable:         # If already true, we flip enable False
+                                enable = False
+                            elif not iftrigger:   # If False, but not triggered yet, we'll check expression
+                                result = self.evalexpr(args)
+                                if result:
+                                    enable  = True
+                                    iftrigger = True
+                    else:
+                        self.error(self.source,dirtokens[0].lineno,"Misplaced #elif")
+                        
+                elif name == 'else':
+                    if ifstack:
+                        if ifstack[-1][0]:
+                            if enable:
+                                enable = False
+                            elif not iftrigger:
+                                enable = True
+                                iftrigger = True
+                    else:
+                        self.error(self.source,dirtokens[0].lineno,"Misplaced #else")
+
+                elif name == 'endif':
+                    if ifstack:
+                        enable,iftrigger = ifstack.pop()
+                    else:
+                        self.error(self.source,dirtokens[0].lineno,"Misplaced #endif")
+                else:
+                    # Unknown preprocessor directive
+                    pass
+
+            else:
+                # Normal text
+                if enable:
+                    chunk.extend(x)
+
+        for tok in self.expand_macros(chunk):
+            yield tok
+        chunk = []
+
+    # ----------------------------------------------------------------------
+    # include()
+    #
+    # Implementation of file-inclusion
+    # ----------------------------------------------------------------------
+
+    def include(self,tokens):
+        # Try to extract the filename and then process an include file
+        if not tokens:
+            return
+        if tokens:
+            if tokens[0].value != '<' and tokens[0].type != self.t_STRING:
+                tokens = self.expand_macros(tokens)
+
+            if tokens[0].value == '<':
+                # Include <...>
+                i = 1
+                while i < len(tokens):
+                    if tokens[i].value == '>':
+                        break
+                    i += 1
+                else:
+                    print("Malformed #include <...>")
+                    return
+                filename = "".join([x.value for x in tokens[1:i]])
+                path = self.path + [""] + self.temp_path
+            elif tokens[0].type == self.t_STRING:
+                filename = tokens[0].value[1:-1]
+                path = self.temp_path + [""] + self.path
+            else:
+                print("Malformed #include statement")
+                return
+        for p in path:
+            iname = os.path.join(p,filename)
+            try:
+                data = open(iname,"r").read()
+                dname = os.path.dirname(iname)
+                if dname:
+                    self.temp_path.insert(0,dname)
+                for tok in self.parsegen(data,filename):
+                    yield tok
+                if dname:
+                    del self.temp_path[0]
+                break
+            except IOError:
+                pass
+        else:
+            print("Couldn't find '%s'" % filename)
+
+    # ----------------------------------------------------------------------
+    # define()
+    #
+    # Define a new macro
+    # ----------------------------------------------------------------------
+
+    def define(self,tokens):
+        if isinstance(tokens,(str,unicode)):
+            tokens = self.tokenize(tokens)
+
+        linetok = tokens
+        try:
+            name = linetok[0]
+            if len(linetok) > 1:
+                mtype = linetok[1]
+            else:
+                mtype = None
+            if not mtype:
+                m = Macro(name.value,[])
+                self.macros[name.value] = m
+            elif mtype.type in self.t_WS:
+                # A normal macro
+                m = Macro(name.value,self.tokenstrip(linetok[2:]))
+                self.macros[name.value] = m
+            elif mtype.value == '(':
+                # A macro with arguments
+                tokcount, args, positions = self.collect_args(linetok[1:])
+                variadic = False
+                for a in args:
+                    if variadic:
+                        print("No more arguments may follow a variadic argument")
+                        break
+                    astr = "".join([str(_i.value) for _i in a])
+                    if astr == "...":
+                        variadic = True
+                        a[0].type = self.t_ID
+                        a[0].value = '__VA_ARGS__'
+                        variadic = True
+                        del a[1:]
+                        continue
+                    elif astr[-3:] == "..." and a[0].type == self.t_ID:
+                        variadic = True
+                        del a[1:]
+                        # If, for some reason, "." is part of the identifier, strip off the name for the purposes
+                        # of macro expansion
+                        if a[0].value[-3:] == '...':
+                            a[0].value = a[0].value[:-3]
+                        continue
+                    if len(a) > 1 or a[0].type != self.t_ID:
+                        print("Invalid macro argument")
+                        break
+                else:
+                    mvalue = self.tokenstrip(linetok[1+tokcount:])
+                    i = 0
+                    while i < len(mvalue):
+                        if i+1 < len(mvalue):
+                            if mvalue[i].type in self.t_WS and mvalue[i+1].value == '##':
+                                del mvalue[i]
+                                continue
+                            elif mvalue[i].value == '##' and mvalue[i+1].type in self.t_WS:
+                                del mvalue[i+1]
+                        i += 1
+                    m = Macro(name.value,mvalue,[x[0].value for x in args],variadic)
+                    self.macro_prescan(m)
+                    self.macros[name.value] = m
+            else:
+                print("Bad macro definition")
+        except LookupError:
+            print("Bad macro definition")
+
+    # ----------------------------------------------------------------------
+    # undef()
+    #
+    # Undefine a macro
+    # ----------------------------------------------------------------------
+
+    def undef(self,tokens):
+        id = tokens[0].value
+        try:
+            del self.macros[id]
+        except LookupError:
+            pass
+
+    # ----------------------------------------------------------------------
+    # parse()
+    #
+    # Parse input text.
+    # ----------------------------------------------------------------------
+    def parse(self,input,source=None,ignore={}):
+        self.ignore = ignore
+        self.parser = self.parsegen(input,source)
+        
+    # ----------------------------------------------------------------------
+    # token()
+    #
+    # Method to return individual tokens
+    # ----------------------------------------------------------------------
+    def token(self):
+        try:
+            while True:
+                tok = next(self.parser)
+                if tok.type not in self.ignore: return tok
+        except StopIteration:
+            self.parser = None
+            return None
+
+if __name__ == '__main__':
+    import ply.lex as lex
+    lexer = lex.lex()
+
+    # Run a preprocessor
+    import sys
+    f = open(sys.argv[1])
+    input = f.read()
+
+    p = Preprocessor(lexer)
+    p.parse(input,sys.argv[1])
+    while True:
+        tok = p.token()
+        if not tok: break
+        print(p.source, tok)
+
+
+
+
+    
+
+
+
+
+
+
diff --git a/ply/ctokens.py b/ply/ctokens.py
new file mode 100644
index 0000000..f6f6952
--- /dev/null
+++ b/ply/ctokens.py
@@ -0,0 +1,133 @@
+# ----------------------------------------------------------------------
+# ctokens.py
+#
+# Token specifications for symbols in ANSI C and C++.  This file is
+# meant to be used as a library in other tokenizers.
+# ----------------------------------------------------------------------
+
+# Reserved words
+
+tokens = [
+    # Literals (identifier, integer constant, float constant, string constant, char const)
+    'ID', 'TYPEID', 'INTEGER', 'FLOAT', 'STRING', 'CHARACTER',
+
+    # Operators (+,-,*,/,%,|,&,~,^,<<,>>, ||, &&, !, <, <=, >, >=, ==, !=)
+    'PLUS', 'MINUS', 'TIMES', 'DIVIDE', 'MODULO',
+    'OR', 'AND', 'NOT', 'XOR', 'LSHIFT', 'RSHIFT',
+    'LOR', 'LAND', 'LNOT',
+    'LT', 'LE', 'GT', 'GE', 'EQ', 'NE',
+    
+    # Assignment (=, *=, /=, %=, +=, -=, <<=, >>=, &=, ^=, |=)
+    'EQUALS', 'TIMESEQUAL', 'DIVEQUAL', 'MODEQUAL', 'PLUSEQUAL', 'MINUSEQUAL',
+    'LSHIFTEQUAL','RSHIFTEQUAL', 'ANDEQUAL', 'XOREQUAL', 'OREQUAL',
+
+    # Increment/decrement (++,--)
+    'INCREMENT', 'DECREMENT',
+
+    # Structure dereference (->)
+    'ARROW',
+
+    # Ternary operator (?)
+    'TERNARY',
+    
+    # Delimeters ( ) [ ] { } , . ; :
+    'LPAREN', 'RPAREN',
+    'LBRACKET', 'RBRACKET',
+    'LBRACE', 'RBRACE',
+    'COMMA', 'PERIOD', 'SEMI', 'COLON',
+
+    # Ellipsis (...)
+    'ELLIPSIS',
+]
+    
+# Operators
+t_PLUS             = r'\+'
+t_MINUS            = r'-'
+t_TIMES            = r'\*'
+t_DIVIDE           = r'/'
+t_MODULO           = r'%'
+t_OR               = r'\|'
+t_AND              = r'&'
+t_NOT              = r'~'
+t_XOR              = r'\^'
+t_LSHIFT           = r'<<'
+t_RSHIFT           = r'>>'
+t_LOR              = r'\|\|'
+t_LAND             = r'&&'
+t_LNOT             = r'!'
+t_LT               = r'<'
+t_GT               = r'>'
+t_LE               = r'<='
+t_GE               = r'>='
+t_EQ               = r'=='
+t_NE               = r'!='
+
+# Assignment operators
+
+t_EQUALS           = r'='
+t_TIMESEQUAL       = r'\*='
+t_DIVEQUAL         = r'/='
+t_MODEQUAL         = r'%='
+t_PLUSEQUAL        = r'\+='
+t_MINUSEQUAL       = r'-='
+t_LSHIFTEQUAL      = r'<<='
+t_RSHIFTEQUAL      = r'>>='
+t_ANDEQUAL         = r'&='
+t_OREQUAL          = r'\|='
+t_XOREQUAL         = r'\^='
+
+# Increment/decrement
+t_INCREMENT        = r'\+\+'
+t_DECREMENT        = r'--'
+
+# ->
+t_ARROW            = r'->'
+
+# ?
+t_TERNARY          = r'\?'
+
+# Delimeters
+t_LPAREN           = r'\('
+t_RPAREN           = r'\)'
+t_LBRACKET         = r'\['
+t_RBRACKET         = r'\]'
+t_LBRACE           = r'\{'
+t_RBRACE           = r'\}'
+t_COMMA            = r','
+t_PERIOD           = r'\.'
+t_SEMI             = r';'
+t_COLON            = r':'
+t_ELLIPSIS         = r'\.\.\.'
+
+# Identifiers
+t_ID = r'[A-Za-z_][A-Za-z0-9_]*'
+
+# Integer literal
+t_INTEGER = r'\d+([uU]|[lL]|[uU][lL]|[lL][uU])?'
+
+# Floating literal
+t_FLOAT = r'((\d+)(\.\d+)(e(\+|-)?(\d+))? | (\d+)e(\+|-)?(\d+))([lL]|[fF])?'
+
+# String literal
+t_STRING = r'\"([^\\\n]|(\\.))*?\"'
+
+# Character constant 'c' or L'c'
+t_CHARACTER = r'(L)?\'([^\\\n]|(\\.))*?\''
+
+# Comment (C-Style)
+def t_COMMENT(t):
+    r'/\*(.|\n)*?\*/'
+    t.lexer.lineno += t.value.count('\n')
+    return t
+
+# Comment (C++-Style)
+def t_CPPCOMMENT(t):
+    r'//.*\n'
+    t.lexer.lineno += 1
+    return t
+
+
+    
+
+
+
diff --git a/ply/lex.py b/ply/lex.py
new file mode 100644
index 0000000..8f05537
--- /dev/null
+++ b/ply/lex.py
@@ -0,0 +1,1063 @@
+# -----------------------------------------------------------------------------
+# 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__    = "3.5"
+__tabversion__ = "3.5"       # Version of table file used
+
+import re, sys, types, copy, os, inspect
+
+# 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(__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))
+
+        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") != __tabversion__:
+            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_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):
+    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.modules    = {}
+        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","")
+        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 = 1
+
+        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
+                module = inspect.getmodule(f)
+                self.modules[module] = 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 _get_regex(f):
+                    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, _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 = 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 _get_regex(f):
+                        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
+                module = inspect.getmodule(f)
+                self.modules[module] = 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 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 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:
+                    filename = inspect.getsourcefile(module)
+                    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,_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 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_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
+
diff --git a/ply/yacc.py b/ply/yacc.py
new file mode 100644
index 0000000..49d83d7
--- /dev/null
+++ b/ply/yacc.py
@@ -0,0 +1,3331 @@
+# -----------------------------------------------------------------------------
+# ply: yacc.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.
+# -----------------------------------------------------------------------------
+#
+# This implements an LR parser that is constructed from grammar rules defined
+# as Python functions. The grammer is specified by supplying the BNF inside
+# Python documentation strings.  The inspiration for this technique was borrowed
+# from John Aycock's Spark parsing system.  PLY might be viewed as cross between
+# Spark and the GNU bison utility.
+#
+# The current implementation is only somewhat object-oriented. The
+# LR parser itself is defined in terms of an object (which allows multiple
+# parsers to co-exist).  However, most of the variables used during table
+# construction are defined in terms of global variables.  Users shouldn't
+# notice unless they are trying to define multiple parsers at the same
+# time using threads (in which case they should have their head examined).
+#
+# This implementation supports both SLR and LALR(1) parsing.  LALR(1)
+# support was originally implemented by Elias Ioup (ezioup@alumni.uchicago.edu),
+# using the algorithm found in Aho, Sethi, and Ullman "Compilers: Principles,
+# Techniques, and Tools" (The Dragon Book).  LALR(1) has since been replaced
+# by the more efficient DeRemer and Pennello algorithm.
+#
+# :::::::: WARNING :::::::
+#
+# Construction of LR parsing tables is fairly complicated and expensive.
+# To make this module run fast, a *LOT* of work has been put into
+# optimization---often at the expensive of readability and what might
+# consider to be good Python "coding style."   Modify the code at your
+# own risk!
+# ----------------------------------------------------------------------------
+
+__version__    = "3.5"
+__tabversion__ = "3.2"       # Table version
+
+#-----------------------------------------------------------------------------
+#                     === User configurable parameters ===
+#
+# Change these to modify the default behavior of yacc (if you wish)
+#-----------------------------------------------------------------------------
+
+yaccdebug   = 1                # Debugging mode.  If set, yacc generates a
+                               # a 'parser.out' file in the current directory
+
+debug_file  = 'parser.out'     # Default name of the debugging file
+tab_module  = 'parsetab'       # Default name of the table module
+default_lr  = 'LALR'           # Default LR table generation method
+
+error_count = 3                # Number of symbols that must be shifted to leave recovery mode
+
+yaccdevel   = 0                # Set to True if developing yacc.  This turns off optimized
+                               # implementations of certain functions.
+
+resultlimit = 40               # Size limit of results when running in debug mode.
+
+pickle_protocol = 0            # Protocol to use when writing pickle files
+
+import re, types, sys, os.path, inspect
+
+# Compatibility function for python 2.6/3.0
+if sys.version_info[0] < 3:
+    def func_code(f):
+        return f.func_code
+else:
+    def func_code(f):
+        return f.__code__
+
+# String type-checking compatibility
+if sys.version_info[0] < 3:
+    string_types = basestring
+else:
+    string_types = str
+
+# Compatibility
+try:
+    MAXINT = sys.maxint
+except AttributeError:
+    MAXINT = sys.maxsize
+
+# Python 2.x/3.0 compatibility.
+def load_ply_lex():
+    if sys.version_info[0] < 3:
+        import lex
+    else:
+        import ply.lex as lex
+    return lex
+
+# This object is a stand-in for a logging object created by the 
+# logging module.   PLY will use this by default to create things
+# such as the parser.out file.  If a user wants more detailed
+# information, they can create their own logging object and pass
+# it into PLY.
+
+class PlyLogger(object):
+    def __init__(self,f):
+        self.f = f
+    def debug(self,msg,*args,**kwargs):
+        self.f.write((msg % args) + "\n")
+    info     = debug
+
+    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")
+
+    critical = debug
+
+# 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
+        
+# Exception raised for yacc-related errors
+class YaccError(Exception):   pass
+
+# Format the result message that the parser produces when running in debug mode.
+def format_result(r):
+    repr_str = repr(r)
+    if '\n' in repr_str: repr_str = repr(repr_str)
+    if len(repr_str) > resultlimit:
+        repr_str = repr_str[:resultlimit]+" ..."
+    result = "<%s @ 0x%x> (%s)" % (type(r).__name__,id(r),repr_str)
+    return result
+
+
+# Format stack entries when the parser is running in debug mode
+def format_stack_entry(r):
+    repr_str = repr(r)
+    if '\n' in repr_str: repr_str = repr(repr_str)
+    if len(repr_str) < 16:
+        return repr_str
+    else:
+        return "<%s @ 0x%x>" % (type(r).__name__,id(r))
+
+# Panic mode error recovery support.   This feature is being reworked--much of the
+# code here is to offer a deprecation/backwards compatible transition
+
+_errok = None
+_token = None
+_restart = None
+_warnmsg = """PLY: Don't use global functions errok(), token(), and restart() in p_error().
+Instead, invoke the methods on the associated parser instance:
+
+    def p_error(p):
+        ...
+        # Use parser.errok(), parser.token(), parser.restart()
+        ...
+
+    parser = yacc.yacc()
+"""
+import warnings
+def errok():
+    warnings.warn(_warnmsg)
+    return _errok()
+
+def restart():
+    warnings.warn(_warnmsg)
+    return _restart()
+
+def token():
+    warnings.warn(_warnmsg)
+    return _token()
+
+# Utility function to call the p_error() function with some deprecation hacks
+def call_errorfunc(errorfunc,token,parser):
+    global _errok, _token, _restart
+    _errok = parser.errok
+    _token = parser.token
+    _restart = parser.restart
+    r = errorfunc(token)
+    del _errok, _token, _restart
+
+#-----------------------------------------------------------------------------
+#                        ===  LR Parsing Engine ===
+#
+# The following classes are used for the LR parser itself.  These are not
+# used during table construction and are independent of the actual LR
+# table generation algorithm
+#-----------------------------------------------------------------------------
+
+# This class is used to hold non-terminal grammar symbols during parsing.
+# It normally has the following attributes set:
+#        .type       = Grammar symbol type
+#        .value      = Symbol value
+#        .lineno     = Starting line number
+#        .endlineno  = Ending line number (optional, set automatically)
+#        .lexpos     = Starting lex position
+#        .endlexpos  = Ending lex position (optional, set automatically)
+
+class YaccSymbol:
+    def __str__(self):    return self.type
+    def __repr__(self):   return str(self)
+
+# This class is a wrapper around the objects actually passed to each
+# grammar rule.   Index lookup and assignment actually assign the
+# .value attribute of the underlying YaccSymbol object.
+# The lineno() method returns the line number of a given
+# item (or 0 if not defined).   The linespan() method returns
+# a tuple of (startline,endline) representing the range of lines
+# for a symbol.  The lexspan() method returns a tuple (lexpos,endlexpos)
+# representing the range of positional information for a symbol.
+
+class YaccProduction:
+    def __init__(self,s,stack=None):
+        self.slice = s
+        self.stack = stack
+        self.lexer = None
+        self.parser= None
+    def __getitem__(self,n):
+        if isinstance(n, slice):
+            return [s.value for s in self.slice[n]]
+        elif n >= 0: 
+            return self.slice[n].value
+        else: 
+            return self.stack[n].value
+
+    def __setitem__(self,n,v):
+        self.slice[n].value = v
+
+    def __getslice__(self,i,j):
+        return [s.value for s in self.slice[i:j]]
+
+    def __len__(self):
+        return len(self.slice)
+
+    def lineno(self,n):
+        return getattr(self.slice[n],"lineno",0)
+
+    def set_lineno(self,n,lineno):
+        self.slice[n].lineno = lineno
+
+    def linespan(self,n):
+        startline = getattr(self.slice[n],"lineno",0)
+        endline = getattr(self.slice[n],"endlineno",startline)
+        return startline,endline
+
+    def lexpos(self,n):
+        return getattr(self.slice[n],"lexpos",0)
+
+    def lexspan(self,n):
+        startpos = getattr(self.slice[n],"lexpos",0)
+        endpos = getattr(self.slice[n],"endlexpos",startpos)
+        return startpos,endpos
+
+    def error(self):
+       raise SyntaxError
+
+
+# -----------------------------------------------------------------------------
+#                               == LRParser ==
+#
+# The LR Parsing engine.
+# -----------------------------------------------------------------------------
+
+class LRParser:
+    def __init__(self,lrtab,errorf):
+        self.productions = lrtab.lr_productions
+        self.action      = lrtab.lr_action
+        self.goto        = lrtab.lr_goto
+        self.errorfunc   = errorf
+
+    def errok(self):
+        self.errorok     = 1
+
+    def restart(self):
+        del self.statestack[:]
+        del self.symstack[:]
+        sym = YaccSymbol()
+        sym.type = '$end'
+        self.symstack.append(sym)
+        self.statestack.append(0)
+
+    def parse(self,input=None,lexer=None,debug=0,tracking=0,tokenfunc=None):
+        if debug or yaccdevel:
+            if isinstance(debug,int):
+                debug = PlyLogger(sys.stderr)
+            return self.parsedebug(input,lexer,debug,tracking,tokenfunc)
+        elif tracking:
+            return self.parseopt(input,lexer,debug,tracking,tokenfunc)
+        else:
+            return self.parseopt_notrack(input,lexer,debug,tracking,tokenfunc)
+        
+
+    # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+    # parsedebug().
+    #
+    # This is the debugging enabled version of parse().  All changes made to the
+    # parsing engine should be made here.   For the non-debugging version,
+    # copy this code to a method parseopt() and delete all of the sections
+    # enclosed in:
+    #
+    #      #--! DEBUG
+    #      statements
+    #      #--! DEBUG
+    #
+    # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+    def parsedebug(self,input=None,lexer=None,debug=None,tracking=0,tokenfunc=None):
+        lookahead = None                 # Current lookahead symbol
+        lookaheadstack = [ ]             # Stack of lookahead symbols
+        actions = self.action            # Local reference to action table (to avoid lookup on self.)
+        goto    = self.goto              # Local reference to goto table (to avoid lookup on self.)
+        prod    = self.productions       # Local reference to production list (to avoid lookup on self.)
+        pslice  = YaccProduction(None)   # Production object passed to grammar rules
+        errorcount = 0                   # Used during error recovery 
+
+        # --! DEBUG
+        debug.info("PLY: PARSE DEBUG START")
+        # --! DEBUG
+
+        # If no lexer was given, we will try to use the lex module
+        if not lexer:
+            lex = load_ply_lex()
+            lexer = lex.lexer
+
+        # Set up the lexer and parser objects on pslice
+        pslice.lexer = lexer
+        pslice.parser = self
+
+        # If input was supplied, pass to lexer
+        if input is not None:
+            lexer.input(input)
+
+        if tokenfunc is None:
+           # Tokenize function
+           get_token = lexer.token
+        else:
+           get_token = tokenfunc
+
+        # Set the parser() token method (sometimes used in error recovery)
+        self.token = get_token
+
+        # Set up the state and symbol stacks
+
+        statestack = [ ]                # Stack of parsing states
+        self.statestack = statestack
+        symstack   = [ ]                # Stack of grammar symbols
+        self.symstack = symstack
+
+        pslice.stack = symstack         # Put in the production
+        errtoken   = None               # Err token
+
+        # The start state is assumed to be (0,$end)
+
+        statestack.append(0)
+        sym = YaccSymbol()
+        sym.type = "$end"
+        symstack.append(sym)
+        state = 0
+        while 1:
+            # Get the next symbol on the input.  If a lookahead symbol
+            # is already set, we just use that. Otherwise, we'll pull
+            # the next token off of the lookaheadstack or from the lexer
+
+            # --! DEBUG
+            debug.debug('')
+            debug.debug('State  : %s', state)
+            # --! DEBUG
+
+            if not lookahead:
+                if not lookaheadstack:
+                    lookahead = get_token()     # Get the next token
+                else:
+                    lookahead = lookaheadstack.pop()
+                if not lookahead:
+                    lookahead = YaccSymbol()
+                    lookahead.type = "$end"
+
+            # --! DEBUG
+            debug.debug('Stack  : %s',
+                        ("%s . %s" % (" ".join([xx.type for xx in symstack][1:]), str(lookahead))).lstrip())
+            # --! DEBUG
+
+            # Check the action table
+            ltype = lookahead.type
+            t = actions[state].get(ltype)
+
+            if t is not None:
+                if t > 0:
+                    # shift a symbol on the stack
+                    statestack.append(t)
+                    state = t
+                    
+                    # --! DEBUG
+                    debug.debug("Action : Shift and goto state %s", t)
+                    # --! DEBUG
+
+                    symstack.append(lookahead)
+                    lookahead = None
+
+                    # Decrease error count on successful shift
+                    if errorcount: errorcount -=1
+                    continue
+
+                if t < 0:
+                    # reduce a symbol on the stack, emit a production
+                    p = prod[-t]
+                    pname = p.name
+                    plen  = p.len
+
+                    # Get production function
+                    sym = YaccSymbol()
+                    sym.type = pname       # Production name
+                    sym.value = None
+
+                    # --! DEBUG
+                    if plen:
+                        debug.info("Action : Reduce rule [%s] with %s and goto state %d", p.str, "["+",".join([format_stack_entry(_v.value) for _v in symstack[-plen:]])+"]",-t)
+                    else:
+                        debug.info("Action : Reduce rule [%s] with %s and goto state %d", p.str, [],-t)
+                        
+                    # --! DEBUG
+
+                    if plen:
+                        targ = symstack[-plen-1:]
+                        targ[0] = sym
+
+                        # --! TRACKING
+                        if tracking:
+                           t1 = targ[1]
+                           sym.lineno = t1.lineno
+                           sym.lexpos = t1.lexpos
+                           t1 = targ[-1]
+                           sym.endlineno = getattr(t1,"endlineno",t1.lineno)
+                           sym.endlexpos = getattr(t1,"endlexpos",t1.lexpos)
+
+                        # --! TRACKING
+
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+                        # The code enclosed in this section is duplicated 
+                        # below as a performance optimization.  Make sure
+                        # changes get made in both locations.
+
+                        pslice.slice = targ
+                        
+                        try:
+                            # Call the grammar rule with our special slice object
+                            del symstack[-plen:]
+                            del statestack[-plen:]
+                            p.callable(pslice)
+                            # --! DEBUG
+                            debug.info("Result : %s", format_result(pslice[0]))
+                            # --! DEBUG
+                            symstack.append(sym)
+                            state = goto[statestack[-1]][pname]
+                            statestack.append(state)
+                        except SyntaxError:
+                            # If an error was set. Enter error recovery state
+                            lookaheadstack.append(lookahead)
+                            symstack.pop()
+                            statestack.pop()
+                            state = statestack[-1]
+                            sym.type = 'error'
+                            lookahead = sym
+                            errorcount = error_count
+                            self.errorok = 0
+                        continue
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+    
+                    else:
+
+                        # --! TRACKING
+                        if tracking:
+                           sym.lineno = lexer.lineno
+                           sym.lexpos = lexer.lexpos
+                        # --! TRACKING
+
+                        targ = [ sym ]
+
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+                        # The code enclosed in this section is duplicated 
+                        # above as a performance optimization.  Make sure
+                        # changes get made in both locations.
+
+                        pslice.slice = targ
+
+                        try:
+                            # Call the grammar rule with our special slice object
+                            p.callable(pslice)
+                            # --! DEBUG
+                            debug.info("Result : %s", format_result(pslice[0]))
+                            # --! DEBUG
+                            symstack.append(sym)
+                            state = goto[statestack[-1]][pname]
+                            statestack.append(state)
+                        except SyntaxError:
+                            # If an error was set. Enter error recovery state
+                            lookaheadstack.append(lookahead)
+                            symstack.pop()
+                            statestack.pop()
+                            state = statestack[-1]
+                            sym.type = 'error'
+                            lookahead = sym
+                            errorcount = error_count
+                            self.errorok = 0
+                        continue
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+                if t == 0:
+                    n = symstack[-1]
+                    result = getattr(n,"value",None)
+                    # --! DEBUG
+                    debug.info("Done   : Returning %s", format_result(result))
+                    debug.info("PLY: PARSE DEBUG END")
+                    # --! DEBUG
+                    return result
+
+            if t == None:
+
+                # --! DEBUG
+                debug.error('Error  : %s',
+                            ("%s . %s" % (" ".join([xx.type for xx in symstack][1:]), str(lookahead))).lstrip())
+                # --! DEBUG
+
+                # We have some kind of parsing error here.  To handle
+                # this, we are going to push the current token onto
+                # the tokenstack and replace it with an 'error' token.
+                # If there are any synchronization rules, they may
+                # catch it.
+                #
+                # In addition to pushing the error token, we call call
+                # the user defined p_error() function if this is the
+                # first syntax error.  This function is only called if
+                # errorcount == 0.
+                if errorcount == 0 or self.errorok:
+                    errorcount = error_count
+                    self.errorok = 0
+                    errtoken = lookahead
+                    if errtoken.type == "$end":
+                        errtoken = None               # End of file!
+                    if self.errorfunc:
+                        if errtoken and not hasattr(errtoken,'lexer'):
+                            errtoken.lexer = lexer
+                        tok = call_errorfunc(self.errorfunc, errtoken, self)
+                        if self.errorok:
+                            # User must have done some kind of panic
+                            # mode recovery on their own.  The
+                            # returned token is the next lookahead
+                            lookahead = tok
+                            errtoken = None
+                            continue
+                    else:
+                        if errtoken:
+                            if hasattr(errtoken,"lineno"): lineno = lookahead.lineno
+                            else: lineno = 0
+                            if lineno:
+                                sys.stderr.write("yacc: Syntax error at line %d, token=%s\n" % (lineno, errtoken.type))
+                            else:
+                                sys.stderr.write("yacc: Syntax error, token=%s" % errtoken.type)
+                        else:
+                            sys.stderr.write("yacc: Parse error in input. EOF\n")
+                            return
+
+                else:
+                    errorcount = error_count
+
+                # case 1:  the statestack only has 1 entry on it.  If we're in this state, the
+                # entire parse has been rolled back and we're completely hosed.   The token is
+                # discarded and we just keep going.
+
+                if len(statestack) <= 1 and lookahead.type != "$end":
+                    lookahead = None
+                    errtoken = None
+                    state = 0
+                    # Nuke the pushback stack
+                    del lookaheadstack[:]
+                    continue
+
+                # case 2: the statestack has a couple of entries on it, but we're
+                # at the end of the file. nuke the top entry and generate an error token
+
+                # Start nuking entries on the stack
+                if lookahead.type == "$end":
+                    # Whoa. We're really hosed here. Bail out
+                    return
+
+                if lookahead.type != 'error':
+                    sym = symstack[-1]
+                    if sym.type == 'error':
+                        # Hmmm. Error is on top of stack, we'll just nuke input
+                        # symbol and continue
+                        if tracking:
+                            sym.endlineno = getattr(lookahead,"lineno", sym.lineno)
+                            sym.endlexpos = getattr(lookahead,"lexpos", sym.lexpos)
+                        lookahead = None
+                        continue
+                    t = YaccSymbol()
+                    t.type = 'error'
+                    if hasattr(lookahead,"lineno"):
+                        t.lineno = lookahead.lineno
+                    if hasattr(lookahead,"lexpos"):
+                        t.lexpos = lookahead.lexpos
+                    t.value = lookahead
+                    lookaheadstack.append(lookahead)
+                    lookahead = t
+                else:
+                    sym = symstack.pop()
+                    if tracking:
+                        lookahead.lineno = sym.lineno
+                        lookahead.lexpos = sym.lexpos
+                    statestack.pop()
+                    state = statestack[-1]       # Potential bug fix
+
+                continue
+
+            # Call an error function here
+            raise RuntimeError("yacc: internal parser error!!!\n")
+
+    # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+    # parseopt().
+    #
+    # Optimized version of parse() method.  DO NOT EDIT THIS CODE DIRECTLY.
+    # Edit the debug version above, then copy any modifications to the method
+    # below while removing #--! DEBUG sections.
+    # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+
+    def parseopt(self,input=None,lexer=None,debug=0,tracking=0,tokenfunc=None):
+        lookahead = None                 # Current lookahead symbol
+        lookaheadstack = [ ]             # Stack of lookahead symbols
+        actions = self.action            # Local reference to action table (to avoid lookup on self.)
+        goto    = self.goto              # Local reference to goto table (to avoid lookup on self.)
+        prod    = self.productions       # Local reference to production list (to avoid lookup on self.)
+        pslice  = YaccProduction(None)   # Production object passed to grammar rules
+        errorcount = 0                   # Used during error recovery 
+
+        # If no lexer was given, we will try to use the lex module
+        if not lexer:
+            lex = load_ply_lex()
+            lexer = lex.lexer
+        
+        # Set up the lexer and parser objects on pslice
+        pslice.lexer = lexer
+        pslice.parser = self
+
+        # If input was supplied, pass to lexer
+        if input is not None:
+            lexer.input(input)
+
+        if tokenfunc is None:
+           # Tokenize function
+           get_token = lexer.token
+        else:
+           get_token = tokenfunc
+
+        # Set the parser() token method (sometimes used in error recovery)
+        self.token = get_token
+
+        # Set up the state and symbol stacks
+
+        statestack = [ ]                # Stack of parsing states
+        self.statestack = statestack
+        symstack   = [ ]                # Stack of grammar symbols
+        self.symstack = symstack
+
+        pslice.stack = symstack         # Put in the production
+        errtoken   = None               # Err token
+
+        # The start state is assumed to be (0,$end)
+
+        statestack.append(0)
+        sym = YaccSymbol()
+        sym.type = '$end'
+        symstack.append(sym)
+        state = 0
+        while 1:
+            # Get the next symbol on the input.  If a lookahead symbol
+            # is already set, we just use that. Otherwise, we'll pull
+            # the next token off of the lookaheadstack or from the lexer
+
+            if not lookahead:
+                if not lookaheadstack:
+                    lookahead = get_token()     # Get the next token
+                else:
+                    lookahead = lookaheadstack.pop()
+                if not lookahead:
+                    lookahead = YaccSymbol()
+                    lookahead.type = '$end'
+
+            # Check the action table
+            ltype = lookahead.type
+            t = actions[state].get(ltype)
+
+            if t is not None:
+                if t > 0:
+                    # shift a symbol on the stack
+                    statestack.append(t)
+                    state = t
+
+                    symstack.append(lookahead)
+                    lookahead = None
+
+                    # Decrease error count on successful shift
+                    if errorcount: errorcount -=1
+                    continue
+
+                if t < 0:
+                    # reduce a symbol on the stack, emit a production
+                    p = prod[-t]
+                    pname = p.name
+                    plen  = p.len
+
+                    # Get production function
+                    sym = YaccSymbol()
+                    sym.type = pname       # Production name
+                    sym.value = None
+
+                    if plen:
+                        targ = symstack[-plen-1:]
+                        targ[0] = sym
+
+                        # --! TRACKING
+                        if tracking:
+                           t1 = targ[1]
+                           sym.lineno = t1.lineno
+                           sym.lexpos = t1.lexpos
+                           t1 = targ[-1]
+                           sym.endlineno = getattr(t1,"endlineno",t1.lineno)
+                           sym.endlexpos = getattr(t1,"endlexpos",t1.lexpos)
+
+                        # --! TRACKING
+
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+                        # The code enclosed in this section is duplicated 
+                        # below as a performance optimization.  Make sure
+                        # changes get made in both locations.
+
+                        pslice.slice = targ
+                        
+                        try:
+                            # Call the grammar rule with our special slice object
+                            del symstack[-plen:]
+                            del statestack[-plen:]
+                            p.callable(pslice)
+                            symstack.append(sym)
+                            state = goto[statestack[-1]][pname]
+                            statestack.append(state)
+                        except SyntaxError:
+                            # If an error was set. Enter error recovery state
+                            lookaheadstack.append(lookahead)
+                            symstack.pop()
+                            statestack.pop()
+                            state = statestack[-1]
+                            sym.type = 'error'
+                            lookahead = sym
+                            errorcount = error_count
+                            self.errorok = 0
+                        continue
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+    
+                    else:
+
+                        # --! TRACKING
+                        if tracking:
+                           sym.lineno = lexer.lineno
+                           sym.lexpos = lexer.lexpos
+                        # --! TRACKING
+
+                        targ = [ sym ]
+
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+                        # The code enclosed in this section is duplicated 
+                        # above as a performance optimization.  Make sure
+                        # changes get made in both locations.
+
+                        pslice.slice = targ
+
+                        try:
+                            # Call the grammar rule with our special slice object
+                            p.callable(pslice)
+                            symstack.append(sym)
+                            state = goto[statestack[-1]][pname]
+                            statestack.append(state)
+                        except SyntaxError:
+                            # If an error was set. Enter error recovery state
+                            lookaheadstack.append(lookahead)
+                            symstack.pop()
+                            statestack.pop()
+                            state = statestack[-1]
+                            sym.type = 'error'
+                            lookahead = sym
+                            errorcount = error_count
+                            self.errorok = 0
+                        continue
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+                if t == 0:
+                    n = symstack[-1]
+                    return getattr(n,"value",None)
+
+            if t == None:
+
+                # We have some kind of parsing error here.  To handle
+                # this, we are going to push the current token onto
+                # the tokenstack and replace it with an 'error' token.
+                # If there are any synchronization rules, they may
+                # catch it.
+                #
+                # In addition to pushing the error token, we call call
+                # the user defined p_error() function if this is the
+                # first syntax error.  This function is only called if
+                # errorcount == 0.
+                if errorcount == 0 or self.errorok:
+                    errorcount = error_count
+                    self.errorok = 0
+                    errtoken = lookahead
+                    if errtoken.type == '$end':
+                        errtoken = None               # End of file!
+                    if self.errorfunc:
+                        if errtoken and not hasattr(errtoken,'lexer'):
+                            errtoken.lexer = lexer
+                        tok = call_errorfunc(self.errorfunc, errtoken, self)
+
+                        if self.errorok:
+                            # User must have done some kind of panic
+                            # mode recovery on their own.  The
+                            # returned token is the next lookahead
+                            lookahead = tok
+                            errtoken = None
+                            continue
+                    else:
+                        if errtoken:
+                            if hasattr(errtoken,"lineno"): lineno = lookahead.lineno
+                            else: lineno = 0
+                            if lineno:
+                                sys.stderr.write("yacc: Syntax error at line %d, token=%s\n" % (lineno, errtoken.type))
+                            else:
+                                sys.stderr.write("yacc: Syntax error, token=%s" % errtoken.type)
+                        else:
+                            sys.stderr.write("yacc: Parse error in input. EOF\n")
+                            return
+
+                else:
+                    errorcount = error_count
+
+                # case 1:  the statestack only has 1 entry on it.  If we're in this state, the
+                # entire parse has been rolled back and we're completely hosed.   The token is
+                # discarded and we just keep going.
+
+                if len(statestack) <= 1 and lookahead.type != '$end':
+                    lookahead = None
+                    errtoken = None
+                    state = 0
+                    # Nuke the pushback stack
+                    del lookaheadstack[:]
+                    continue
+
+                # case 2: the statestack has a couple of entries on it, but we're
+                # at the end of the file. nuke the top entry and generate an error token
+
+                # Start nuking entries on the stack
+                if lookahead.type == '$end':
+                    # Whoa. We're really hosed here. Bail out
+                    return
+
+                if lookahead.type != 'error':
+                    sym = symstack[-1]
+                    if sym.type == 'error':
+                        # Hmmm. Error is on top of stack, we'll just nuke input
+                        # symbol and continue
+                        if tracking:
+                            sym.endlineno = getattr(lookahead,"lineno", sym.lineno)
+                            sym.endlexpos = getattr(lookahead,"lexpos", sym.lexpos)
+                        lookahead = None
+                        continue
+                    t = YaccSymbol()
+                    t.type = 'error'
+                    if hasattr(lookahead,"lineno"):
+                        t.lineno = lookahead.lineno
+                    if hasattr(lookahead,"lexpos"):
+                        t.lexpos = lookahead.lexpos
+                    t.value = lookahead
+                    lookaheadstack.append(lookahead)
+                    lookahead = t
+                else:
+                    sym = symstack.pop()
+                    if tracking:
+                        lookahead.lineno = sym.lineno
+                        lookahead.lexpos = sym.lexpos
+                    statestack.pop()
+                    state = statestack[-1]       # Potential bug fix
+
+                continue
+
+            # Call an error function here
+            raise RuntimeError("yacc: internal parser error!!!\n")
+
+    # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+    # parseopt_notrack().
+    #
+    # Optimized version of parseopt() with line number tracking removed. 
+    # DO NOT EDIT THIS CODE DIRECTLY. Copy the optimized version and remove
+    # code in the #--! TRACKING sections
+    # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+    def parseopt_notrack(self,input=None,lexer=None,debug=0,tracking=0,tokenfunc=None):
+        lookahead = None                 # Current lookahead symbol
+        lookaheadstack = [ ]             # Stack of lookahead symbols
+        actions = self.action            # Local reference to action table (to avoid lookup on self.)
+        goto    = self.goto              # Local reference to goto table (to avoid lookup on self.)
+        prod    = self.productions       # Local reference to production list (to avoid lookup on self.)
+        pslice  = YaccProduction(None)   # Production object passed to grammar rules
+        errorcount = 0                   # Used during error recovery 
+
+        # If no lexer was given, we will try to use the lex module
+        if not lexer:
+            lex = load_ply_lex()
+            lexer = lex.lexer
+        
+        # Set up the lexer and parser objects on pslice
+        pslice.lexer = lexer
+        pslice.parser = self
+
+        # If input was supplied, pass to lexer
+        if input is not None:
+            lexer.input(input)
+
+        if tokenfunc is None:
+           # Tokenize function
+           get_token = lexer.token
+        else:
+           get_token = tokenfunc
+
+        # Set the parser() token method (sometimes used in error recovery)
+        self.token = get_token
+
+        # Set up the state and symbol stacks
+
+        statestack = [ ]                # Stack of parsing states
+        self.statestack = statestack
+        symstack   = [ ]                # Stack of grammar symbols
+        self.symstack = symstack
+
+        pslice.stack = symstack         # Put in the production
+        errtoken   = None               # Err token
+
+        # The start state is assumed to be (0,$end)
+
+        statestack.append(0)
+        sym = YaccSymbol()
+        sym.type = '$end'
+        symstack.append(sym)
+        state = 0
+        while 1:
+            # Get the next symbol on the input.  If a lookahead symbol
+            # is already set, we just use that. Otherwise, we'll pull
+            # the next token off of the lookaheadstack or from the lexer
+
+            if not lookahead:
+                if not lookaheadstack:
+                    lookahead = get_token()     # Get the next token
+                else:
+                    lookahead = lookaheadstack.pop()
+                if not lookahead:
+                    lookahead = YaccSymbol()
+                    lookahead.type = '$end'
+
+            # Check the action table
+            ltype = lookahead.type
+            t = actions[state].get(ltype)
+
+            if t is not None:
+                if t > 0:
+                    # shift a symbol on the stack
+                    statestack.append(t)
+                    state = t
+
+                    symstack.append(lookahead)
+                    lookahead = None
+
+                    # Decrease error count on successful shift
+                    if errorcount: errorcount -=1
+                    continue
+
+                if t < 0:
+                    # reduce a symbol on the stack, emit a production
+                    p = prod[-t]
+                    pname = p.name
+                    plen  = p.len
+
+                    # Get production function
+                    sym = YaccSymbol()
+                    sym.type = pname       # Production name
+                    sym.value = None
+
+                    if plen:
+                        targ = symstack[-plen-1:]
+                        targ[0] = sym
+
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+                        # The code enclosed in this section is duplicated 
+                        # below as a performance optimization.  Make sure
+                        # changes get made in both locations.
+
+                        pslice.slice = targ
+                        
+                        try:
+                            # Call the grammar rule with our special slice object
+                            del symstack[-plen:]
+                            del statestack[-plen:]
+                            p.callable(pslice)
+                            symstack.append(sym)
+                            state = goto[statestack[-1]][pname]
+                            statestack.append(state)
+                        except SyntaxError:
+                            # If an error was set. Enter error recovery state
+                            lookaheadstack.append(lookahead)
+                            symstack.pop()
+                            statestack.pop()
+                            state = statestack[-1]
+                            sym.type = 'error'
+                            lookahead = sym
+                            errorcount = error_count
+                            self.errorok = 0
+                        continue
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+    
+                    else:
+
+                        targ = [ sym ]
+
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+                        # The code enclosed in this section is duplicated 
+                        # above as a performance optimization.  Make sure
+                        # changes get made in both locations.
+
+                        pslice.slice = targ
+
+                        try:
+                            # Call the grammar rule with our special slice object
+                            p.callable(pslice)
+                            symstack.append(sym)
+                            state = goto[statestack[-1]][pname]
+                            statestack.append(state)
+                        except SyntaxError:
+                            # If an error was set. Enter error recovery state
+                            lookaheadstack.append(lookahead)
+                            symstack.pop()
+                            statestack.pop()
+                            state = statestack[-1]
+                            sym.type = 'error'
+                            lookahead = sym
+                            errorcount = error_count
+                            self.errorok = 0
+                        continue
+                        # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+                if t == 0:
+                    n = symstack[-1]
+                    return getattr(n,"value",None)
+
+            if t == None:
+
+                # We have some kind of parsing error here.  To handle
+                # this, we are going to push the current token onto
+                # the tokenstack and replace it with an 'error' token.
+                # If there are any synchronization rules, they may
+                # catch it.
+                #
+                # In addition to pushing the error token, we call call
+                # the user defined p_error() function if this is the
+                # first syntax error.  This function is only called if
+                # errorcount == 0.
+                if errorcount == 0 or self.errorok:
+                    errorcount = error_count
+                    self.errorok = 0
+                    errtoken = lookahead
+                    if errtoken.type == '$end':
+                        errtoken = None               # End of file!
+                    if self.errorfunc:
+                        if errtoken and not hasattr(errtoken,'lexer'):
+                            errtoken.lexer = lexer
+                        tok = call_errorfunc(self.errorfunc, errtoken, self)
+
+                        if self.errorok:
+                            # User must have done some kind of panic
+                            # mode recovery on their own.  The
+                            # returned token is the next lookahead
+                            lookahead = tok
+                            errtoken = None
+                            continue
+                    else:
+                        if errtoken:
+                            if hasattr(errtoken,"lineno"): lineno = lookahead.lineno
+                            else: lineno = 0
+                            if lineno:
+                                sys.stderr.write("yacc: Syntax error at line %d, token=%s\n" % (lineno, errtoken.type))
+                            else:
+                                sys.stderr.write("yacc: Syntax error, token=%s" % errtoken.type)
+                        else:
+                            sys.stderr.write("yacc: Parse error in input. EOF\n")
+                            return
+
+                else:
+                    errorcount = error_count
+
+                # case 1:  the statestack only has 1 entry on it.  If we're in this state, the
+                # entire parse has been rolled back and we're completely hosed.   The token is
+                # discarded and we just keep going.
+
+                if len(statestack) <= 1 and lookahead.type != '$end':
+                    lookahead = None
+                    errtoken = None
+                    state = 0
+                    # Nuke the pushback stack
+                    del lookaheadstack[:]
+                    continue
+
+                # case 2: the statestack has a couple of entries on it, but we're
+                # at the end of the file. nuke the top entry and generate an error token
+
+                # Start nuking entries on the stack
+                if lookahead.type == '$end':
+                    # Whoa. We're really hosed here. Bail out
+                    return
+
+                if lookahead.type != 'error':
+                    sym = symstack[-1]
+                    if sym.type == 'error':
+                        # Hmmm. Error is on top of stack, we'll just nuke input
+                        # symbol and continue
+                        lookahead = None
+                        continue
+                    t = YaccSymbol()
+                    t.type = 'error'
+                    if hasattr(lookahead,"lineno"):
+                        t.lineno = lookahead.lineno
+                    if hasattr(lookahead,"lexpos"):
+                        t.lexpos = lookahead.lexpos
+                    t.value = lookahead
+                    lookaheadstack.append(lookahead)
+                    lookahead = t
+                else:
+                    symstack.pop()
+                    statestack.pop()
+                    state = statestack[-1]       # Potential bug fix
+
+                continue
+
+            # Call an error function here
+            raise RuntimeError("yacc: internal parser error!!!\n")
+
+# -----------------------------------------------------------------------------
+#                          === Grammar Representation ===
+#
+# The following functions, classes, and variables are used to represent and
+# manipulate the rules that make up a grammar. 
+# -----------------------------------------------------------------------------
+
+import re
+
+# regex matching identifiers
+_is_identifier = re.compile(r'^[a-zA-Z0-9_-]+$')
+
+# -----------------------------------------------------------------------------
+# class Production:
+#
+# This class stores the raw information about a single production or grammar rule.
+# A grammar rule refers to a specification such as this:
+#
+#       expr : expr PLUS term 
+#
+# Here are the basic attributes defined on all productions
+#
+#       name     - Name of the production.  For example 'expr'
+#       prod     - A list of symbols on the right side ['expr','PLUS','term']
+#       prec     - Production precedence level
+#       number   - Production number.
+#       func     - Function that executes on reduce
+#       file     - File where production function is defined
+#       lineno   - Line number where production function is defined
+#
+# The following attributes are defined or optional.
+#
+#       len       - Length of the production (number of symbols on right hand side)
+#       usyms     - Set of unique symbols found in the production
+# -----------------------------------------------------------------------------
+
+class Production(object):
+    reduced = 0
+    def __init__(self,number,name,prod,precedence=('right',0),func=None,file='',line=0):
+        self.name     = name
+        self.prod     = tuple(prod)
+        self.number   = number
+        self.func     = func
+        self.callable = None
+        self.file     = file
+        self.line     = line
+        self.prec     = precedence
+
+        # Internal settings used during table construction
+        
+        self.len  = len(self.prod)   # Length of the production
+
+        # Create a list of unique production symbols used in the production
+        self.usyms = [ ]             
+        for s in self.prod:
+            if s not in self.usyms:
+                self.usyms.append(s)
+
+        # List of all LR items for the production
+        self.lr_items = []
+        self.lr_next = None
+
+        # Create a string representation
+        if self.prod:
+            self.str = "%s -> %s" % (self.name," ".join(self.prod))
+        else:
+            self.str = "%s -> <empty>" % self.name
+
+    def __str__(self):
+        return self.str
+
+    def __repr__(self):
+        return "Production("+str(self)+")"
+
+    def __len__(self):
+        return len(self.prod)
+
+    def __nonzero__(self):
+        return 1
+
+    def __getitem__(self,index):
+        return self.prod[index]
+            
+    # Return the nth lr_item from the production (or None if at the end)
+    def lr_item(self,n):
+        if n > len(self.prod): return None
+        p = LRItem(self,n)
+
+        # Precompute the list of productions immediately following.  Hack. Remove later
+        try:
+            p.lr_after = Prodnames[p.prod[n+1]]
+        except (IndexError,KeyError):
+            p.lr_after = []
+        try:
+            p.lr_before = p.prod[n-1]
+        except IndexError:
+            p.lr_before = None
+
+        return p
+    
+    # Bind the production function name to a callable
+    def bind(self,pdict):
+        if self.func:
+            self.callable = pdict[self.func]
+
+# This class serves as a minimal standin for Production objects when
+# reading table data from files.   It only contains information
+# actually used by the LR parsing engine, plus some additional
+# debugging information.
+class MiniProduction(object):
+    def __init__(self,str,name,len,func,file,line):
+        self.name     = name
+        self.len      = len
+        self.func     = func
+        self.callable = None
+        self.file     = file
+        self.line     = line
+        self.str      = str
+    def __str__(self):
+        return self.str
+    def __repr__(self):
+        return "MiniProduction(%s)" % self.str
+
+    # Bind the production function name to a callable
+    def bind(self,pdict):
+        if self.func:
+            self.callable = pdict[self.func]
+
+
+# -----------------------------------------------------------------------------
+# class LRItem
+#
+# This class represents a specific stage of parsing a production rule.  For
+# example: 
+#
+#       expr : expr . PLUS term 
+#
+# In the above, the "." represents the current location of the parse.  Here
+# basic attributes:
+#
+#       name       - Name of the production.  For example 'expr'
+#       prod       - A list of symbols on the right side ['expr','.', 'PLUS','term']
+#       number     - Production number.
+#
+#       lr_next      Next LR item. Example, if we are ' expr -> expr . PLUS term'
+#                    then lr_next refers to 'expr -> expr PLUS . term'
+#       lr_index   - LR item index (location of the ".") in the prod list.
+#       lookaheads - LALR lookahead symbols for this item
+#       len        - Length of the production (number of symbols on right hand side)
+#       lr_after    - List of all productions that immediately follow
+#       lr_before   - Grammar symbol immediately before
+# -----------------------------------------------------------------------------
+
+class LRItem(object):
+    def __init__(self,p,n):
+        self.name       = p.name
+        self.prod       = list(p.prod)
+        self.number     = p.number
+        self.lr_index   = n
+        self.lookaheads = { }
+        self.prod.insert(n,".")
+        self.prod       = tuple(self.prod)
+        self.len        = len(self.prod)
+        self.usyms      = p.usyms
+
+    def __str__(self):
+        if self.prod:
+            s = "%s -> %s" % (self.name," ".join(self.prod))
+        else:
+            s = "%s -> <empty>" % self.name
+        return s
+
+    def __repr__(self):
+        return "LRItem("+str(self)+")"
+
+# -----------------------------------------------------------------------------
+# rightmost_terminal()
+#
+# Return the rightmost terminal from a list of symbols.  Used in add_production()
+# -----------------------------------------------------------------------------
+def rightmost_terminal(symbols, terminals):
+    i = len(symbols) - 1
+    while i >= 0:
+        if symbols[i] in terminals:
+            return symbols[i]
+        i -= 1
+    return None
+
+# -----------------------------------------------------------------------------
+#                           === GRAMMAR CLASS ===
+#
+# The following class represents the contents of the specified grammar along
+# with various computed properties such as first sets, follow sets, LR items, etc.
+# This data is used for critical parts of the table generation process later.
+# -----------------------------------------------------------------------------
+
+class GrammarError(YaccError): pass
+
+class Grammar(object):
+    def __init__(self,terminals):
+        self.Productions  = [None]  # A list of all of the productions.  The first
+                                    # entry is always reserved for the purpose of
+                                    # building an augmented grammar
+
+        self.Prodnames    = { }     # A dictionary mapping the names of nonterminals to a list of all
+                                    # productions of that nonterminal.
+
+        self.Prodmap      = { }     # A dictionary that is only used to detect duplicate
+                                    # productions.
+
+        self.Terminals    = { }     # A dictionary mapping the names of terminal symbols to a
+                                    # list of the rules where they are used.
+
+        for term in terminals:
+            self.Terminals[term] = []
+
+        self.Terminals['error'] = []
+
+        self.Nonterminals = { }     # A dictionary mapping names of nonterminals to a list
+                                    # of rule numbers where they are used.
+
+        self.First        = { }     # A dictionary of precomputed FIRST(x) symbols
+
+        self.Follow       = { }     # A dictionary of precomputed FOLLOW(x) symbols
+
+        self.Precedence   = { }     # Precedence rules for each terminal. Contains tuples of the
+                                    # form ('right',level) or ('nonassoc', level) or ('left',level)
+
+        self.UsedPrecedence = { }   # Precedence rules that were actually used by the grammer.
+                                    # This is only used to provide error checking and to generate
+                                    # a warning about unused precedence rules.
+
+        self.Start = None           # Starting symbol for the grammar
+
+
+    def __len__(self):
+        return len(self.Productions)
+
+    def __getitem__(self,index):
+        return self.Productions[index]
+
+    # -----------------------------------------------------------------------------
+    # set_precedence()
+    #
+    # Sets the precedence for a given terminal. assoc is the associativity such as
+    # 'left','right', or 'nonassoc'.  level is a numeric level.
+    #
+    # -----------------------------------------------------------------------------
+
+    def set_precedence(self,term,assoc,level):
+        assert self.Productions == [None],"Must call set_precedence() before add_production()"
+        if term in self.Precedence:
+            raise GrammarError("Precedence already specified for terminal %r" % term)
+        if assoc not in ['left','right','nonassoc']:
+            raise GrammarError("Associativity must be one of 'left','right', or 'nonassoc'")
+        self.Precedence[term] = (assoc,level)
+ 
+    # -----------------------------------------------------------------------------
+    # add_production()
+    #
+    # Given an action function, this function assembles a production rule and
+    # computes its precedence level.
+    #
+    # The production rule is supplied as a list of symbols.   For example,
+    # a rule such as 'expr : expr PLUS term' has a production name of 'expr' and
+    # symbols ['expr','PLUS','term'].
+    #
+    # Precedence is determined by the precedence of the right-most non-terminal
+    # or the precedence of a terminal specified by %prec.
+    #
+    # A variety of error checks are performed to make sure production symbols
+    # are valid and that %prec is used correctly.
+    # -----------------------------------------------------------------------------
+
+    def add_production(self,prodname,syms,func=None,file='',line=0):
+
+        if prodname in self.Terminals:
+            raise GrammarError("%s:%d: Illegal rule name %r. Already defined as a token" % (file,line,prodname))
+        if prodname == 'error':
+            raise GrammarError("%s:%d: Illegal rule name %r. error is a reserved word" % (file,line,prodname))
+        if not _is_identifier.match(prodname):
+            raise GrammarError("%s:%d: Illegal rule name %r" % (file,line,prodname))
+
+        # Look for literal tokens 
+        for n,s in enumerate(syms):
+            if s[0] in "'\"":
+                 try:
+                     c = eval(s)
+                     if (len(c) > 1):
+                          raise GrammarError("%s:%d: Literal token %s in rule %r may only be a single character" % (file,line,s, prodname))
+                     if not c in self.Terminals:
+                          self.Terminals[c] = []
+                     syms[n] = c
+                     continue
+                 except SyntaxError:
+                     pass
+            if not _is_identifier.match(s) and s != '%prec':
+                raise GrammarError("%s:%d: Illegal name %r in rule %r" % (file,line,s, prodname))
+        
+        # Determine the precedence level
+        if '%prec' in syms:
+            if syms[-1] == '%prec':
+                raise GrammarError("%s:%d: Syntax error. Nothing follows %%prec" % (file,line))
+            if syms[-2] != '%prec':
+                raise GrammarError("%s:%d: Syntax error. %%prec can only appear at the end of a grammar rule" % (file,line))
+            precname = syms[-1]
+            prodprec = self.Precedence.get(precname)
+            if not prodprec:
+                raise GrammarError("%s:%d: Nothing known about the precedence of %r" % (file,line,precname))
+            else:
+                self.UsedPrecedence[precname] = 1
+            del syms[-2:]     # Drop %prec from the rule
+        else:
+            # If no %prec, precedence is determined by the rightmost terminal symbol
+            precname = rightmost_terminal(syms,self.Terminals)
+            prodprec = self.Precedence.get(precname,('right',0)) 
+            
+        # See if the rule is already in the rulemap
+        map = "%s -> %s" % (prodname,syms)
+        if map in self.Prodmap:
+            m = self.Prodmap[map]
+            raise GrammarError("%s:%d: Duplicate rule %s. " % (file,line, m) +
+                               "Previous definition at %s:%d" % (m.file, m.line))
+
+        # From this point on, everything is valid.  Create a new Production instance
+        pnumber  = len(self.Productions)
+        if not prodname in self.Nonterminals:
+            self.Nonterminals[prodname] = [ ]
+
+        # Add the production number to Terminals and Nonterminals
+        for t in syms:
+            if t in self.Terminals:
+                self.Terminals[t].append(pnumber)
+            else:
+                if not t in self.Nonterminals:
+                    self.Nonterminals[t] = [ ]
+                self.Nonterminals[t].append(pnumber)
+
+        # Create a production and add it to the list of productions
+        p = Production(pnumber,prodname,syms,prodprec,func,file,line)
+        self.Productions.append(p)
+        self.Prodmap[map] = p
+
+        # Add to the global productions list
+        try:
+            self.Prodnames[prodname].append(p)
+        except KeyError:
+            self.Prodnames[prodname] = [ p ]
+        return 0
+
+    # -----------------------------------------------------------------------------
+    # set_start()
+    #
+    # Sets the starting symbol and creates the augmented grammar.  Production 
+    # rule 0 is S' -> start where start is the start symbol.
+    # -----------------------------------------------------------------------------
+
+    def set_start(self,start=None):
+        if not start:
+            start = self.Productions[1].name
+        if start not in self.Nonterminals:
+            raise GrammarError("start symbol %s undefined" % start)
+        self.Productions[0] = Production(0,"S'",[start])
+        self.Nonterminals[start].append(0)
+        self.Start = start
+
+    # -----------------------------------------------------------------------------
+    # find_unreachable()
+    #
+    # Find all of the nonterminal symbols that can't be reached from the starting
+    # symbol.  Returns a list of nonterminals that can't be reached.
+    # -----------------------------------------------------------------------------
+
+    def find_unreachable(self):
+        
+        # Mark all symbols that are reachable from a symbol s
+        def mark_reachable_from(s):
+            if reachable[s]:
+                # We've already reached symbol s.
+                return
+            reachable[s] = 1
+            for p in self.Prodnames.get(s,[]):
+                for r in p.prod:
+                    mark_reachable_from(r)
+
+        reachable   = { }
+        for s in list(self.Terminals) + list(self.Nonterminals):
+            reachable[s] = 0
+
+        mark_reachable_from( self.Productions[0].prod[0] )
+
+        return [s for s in list(self.Nonterminals)
+                        if not reachable[s]]
+    
+    # -----------------------------------------------------------------------------
+    # infinite_cycles()
+    #
+    # This function looks at the various parsing rules and tries to detect
+    # infinite recursion cycles (grammar rules where there is no possible way
+    # to derive a string of only terminals).
+    # -----------------------------------------------------------------------------
+
+    def infinite_cycles(self):
+        terminates = {}
+
+        # Terminals:
+        for t in self.Terminals:
+            terminates[t] = 1
+
+        terminates['$end'] = 1
+
+        # Nonterminals:
+
+        # Initialize to false:
+        for n in self.Nonterminals:
+            terminates[n] = 0
+
+        # Then propagate termination until no change:
+        while 1:
+            some_change = 0
+            for (n,pl) in self.Prodnames.items():
+                # Nonterminal n terminates iff any of its productions terminates.
+                for p in pl:
+                    # Production p terminates iff all of its rhs symbols terminate.
+                    for s in p.prod:
+                        if not terminates[s]:
+                            # The symbol s does not terminate,
+                            # so production p does not terminate.
+                            p_terminates = 0
+                            break
+                    else:
+                        # didn't break from the loop,
+                        # so every symbol s terminates
+                        # so production p terminates.
+                        p_terminates = 1
+
+                    if p_terminates:
+                        # symbol n terminates!
+                        if not terminates[n]:
+                            terminates[n] = 1
+                            some_change = 1
+                        # Don't need to consider any more productions for this n.
+                        break
+
+            if not some_change:
+                break
+
+        infinite = []
+        for (s,term) in terminates.items():
+            if not term:
+                if not s in self.Prodnames and not s in self.Terminals and s != 'error':
+                    # s is used-but-not-defined, and we've already warned of that,
+                    # so it would be overkill to say that it's also non-terminating.
+                    pass
+                else:
+                    infinite.append(s)
+
+        return infinite
+
+
+    # -----------------------------------------------------------------------------
+    # undefined_symbols()
+    #
+    # Find all symbols that were used the grammar, but not defined as tokens or
+    # grammar rules.  Returns a list of tuples (sym, prod) where sym in the symbol
+    # and prod is the production where the symbol was used. 
+    # -----------------------------------------------------------------------------
+    def undefined_symbols(self):
+        result = []
+        for p in self.Productions:
+            if not p: continue
+
+            for s in p.prod:
+                if not s in self.Prodnames and not s in self.Terminals and s != 'error':
+                    result.append((s,p))
+        return result
+
+    # -----------------------------------------------------------------------------
+    # unused_terminals()
+    #
+    # Find all terminals that were defined, but not used by the grammar.  Returns
+    # a list of all symbols.
+    # -----------------------------------------------------------------------------
+    def unused_terminals(self):
+        unused_tok = []
+        for s,v in self.Terminals.items():
+            if s != 'error' and not v:
+                unused_tok.append(s)
+
+        return unused_tok
+
+    # ------------------------------------------------------------------------------
+    # unused_rules()
+    #
+    # Find all grammar rules that were defined,  but not used (maybe not reachable)
+    # Returns a list of productions.
+    # ------------------------------------------------------------------------------
+
+    def unused_rules(self):
+        unused_prod = []
+        for s,v in self.Nonterminals.items():
+            if not v:
+                p = self.Prodnames[s][0]
+                unused_prod.append(p)
+        return unused_prod
+
+    # -----------------------------------------------------------------------------
+    # unused_precedence()
+    #
+    # Returns a list of tuples (term,precedence) corresponding to precedence
+    # rules that were never used by the grammar.  term is the name of the terminal
+    # on which precedence was applied and precedence is a string such as 'left' or
+    # 'right' corresponding to the type of precedence. 
+    # -----------------------------------------------------------------------------
+
+    def unused_precedence(self):
+        unused = []
+        for termname in self.Precedence:
+            if not (termname in self.Terminals or termname in self.UsedPrecedence):
+                unused.append((termname,self.Precedence[termname][0]))
+                
+        return unused
+
+    # -------------------------------------------------------------------------
+    # _first()
+    #
+    # Compute the value of FIRST1(beta) where beta is a tuple of symbols.
+    #
+    # During execution of compute_first1, the result may be incomplete.
+    # Afterward (e.g., when called from compute_follow()), it will be complete.
+    # -------------------------------------------------------------------------
+    def _first(self,beta):
+
+        # We are computing First(x1,x2,x3,...,xn)
+        result = [ ]
+        for x in beta:
+            x_produces_empty = 0
+
+            # Add all the non-<empty> symbols of First[x] to the result.
+            for f in self.First[x]:
+                if f == '<empty>':
+                    x_produces_empty = 1
+                else:
+                    if f not in result: result.append(f)
+
+            if x_produces_empty:
+                # We have to consider the next x in beta,
+                # i.e. stay in the loop.
+                pass
+            else:
+                # We don't have to consider any further symbols in beta.
+                break
+        else:
+            # There was no 'break' from the loop,
+            # so x_produces_empty was true for all x in beta,
+            # so beta produces empty as well.
+            result.append('<empty>')
+
+        return result
+
+    # -------------------------------------------------------------------------
+    # compute_first()
+    #
+    # Compute the value of FIRST1(X) for all symbols
+    # -------------------------------------------------------------------------
+    def compute_first(self):
+        if self.First:
+            return self.First
+
+        # Terminals:
+        for t in self.Terminals:
+            self.First[t] = [t]
+
+        self.First['$end'] = ['$end']
+
+        # Nonterminals:
+
+        # Initialize to the empty set:
+        for n in self.Nonterminals:
+            self.First[n] = []
+
+        # Then propagate symbols until no change:
+        while 1:
+            some_change = 0
+            for n in self.Nonterminals:
+                for p in self.Prodnames[n]:
+                    for f in self._first(p.prod):
+                        if f not in self.First[n]:
+                            self.First[n].append( f )
+                            some_change = 1
+            if not some_change:
+                break
+        
+        return self.First
+
+    # ---------------------------------------------------------------------
+    # compute_follow()
+    #
+    # Computes all of the follow sets for every non-terminal symbol.  The
+    # follow set is the set of all symbols that might follow a given
+    # non-terminal.  See the Dragon book, 2nd Ed. p. 189.
+    # ---------------------------------------------------------------------
+    def compute_follow(self,start=None):
+        # If already computed, return the result
+        if self.Follow:
+            return self.Follow
+
+        # If first sets not computed yet, do that first.
+        if not self.First:
+            self.compute_first()
+
+        # Add '$end' to the follow list of the start symbol
+        for k in self.Nonterminals:
+            self.Follow[k] = [ ]
+
+        if not start:
+            start = self.Productions[1].name
+
+        self.Follow[start] = [ '$end' ]
+
+        while 1:
+            didadd = 0
+            for p in self.Productions[1:]:
+                # Here is the production set
+                for i in range(len(p.prod)):
+                    B = p.prod[i]
+                    if B in self.Nonterminals:
+                        # Okay. We got a non-terminal in a production
+                        fst = self._first(p.prod[i+1:])
+                        hasempty = 0
+                        for f in fst:
+                            if f != '<empty>' and f not in self.Follow[B]:
+                                self.Follow[B].append(f)
+                                didadd = 1
+                            if f == '<empty>':
+                                hasempty = 1
+                        if hasempty or i == (len(p.prod)-1):
+                            # Add elements of follow(a) to follow(b)
+                            for f in self.Follow[p.name]:
+                                if f not in self.Follow[B]:
+                                    self.Follow[B].append(f)
+                                    didadd = 1
+            if not didadd: break
+        return self.Follow
+
+
+    # -----------------------------------------------------------------------------
+    # build_lritems()
+    #
+    # This function walks the list of productions and builds a complete set of the
+    # LR items.  The LR items are stored in two ways:  First, they are uniquely
+    # numbered and placed in the list _lritems.  Second, a linked list of LR items
+    # is built for each production.  For example:
+    #
+    #   E -> E PLUS E
+    #
+    # Creates the list
+    #
+    #  [E -> . E PLUS E, E -> E . PLUS E, E -> E PLUS . E, E -> E PLUS E . ]
+    # -----------------------------------------------------------------------------
+
+    def build_lritems(self):
+        for p in self.Productions:
+            lastlri = p
+            i = 0
+            lr_items = []
+            while 1:
+                if i > len(p):
+                    lri = None
+                else:
+                    lri = LRItem(p,i)
+                    # Precompute the list of productions immediately following
+                    try:
+                        lri.lr_after = self.Prodnames[lri.prod[i+1]]
+                    except (IndexError,KeyError):
+                        lri.lr_after = []
+                    try:
+                        lri.lr_before = lri.prod[i-1]
+                    except IndexError:
+                        lri.lr_before = None
+
+                lastlri.lr_next = lri
+                if not lri: break
+                lr_items.append(lri)
+                lastlri = lri
+                i += 1
+            p.lr_items = lr_items
+
+# -----------------------------------------------------------------------------
+#                            == Class LRTable ==
+#
+# This basic class represents a basic table of LR parsing information.  
+# Methods for generating the tables are not defined here.  They are defined
+# in the derived class LRGeneratedTable.
+# -----------------------------------------------------------------------------
+
+class VersionError(YaccError): pass
+
+class LRTable(object):
+    def __init__(self):
+        self.lr_action = None
+        self.lr_goto = None
+        self.lr_productions = None
+        self.lr_method = None
+
+    def read_table(self,module):
+        if isinstance(module,types.ModuleType):
+            parsetab = module
+        else:
+            if sys.version_info[0] < 3:
+                exec("import %s as parsetab" % module)
+            else:
+                env = { }
+                exec("import %s as parsetab" % module, env, env)
+                parsetab = env['parsetab']
+
+        if parsetab._tabversion != __tabversion__:
+            raise VersionError("yacc table file version is out of date")
+
+        self.lr_action = parsetab._lr_action
+        self.lr_goto = parsetab._lr_goto
+
+        self.lr_productions = []
+        for p in parsetab._lr_productions:
+            self.lr_productions.append(MiniProduction(*p))
+
+        self.lr_method = parsetab._lr_method
+        return parsetab._lr_signature
+
+    def read_pickle(self,filename):
+        try:
+            import cPickle as pickle
+        except ImportError:
+            import pickle
+
+        in_f = open(filename,"rb")
+
+        tabversion = pickle.load(in_f)
+        if tabversion != __tabversion__:
+            raise VersionError("yacc table file version is out of date")
+        self.lr_method = pickle.load(in_f)
+        signature      = pickle.load(in_f)
+        self.lr_action = pickle.load(in_f)
+        self.lr_goto   = pickle.load(in_f)
+        productions    = pickle.load(in_f)
+
+        self.lr_productions = []
+        for p in productions:
+            self.lr_productions.append(MiniProduction(*p))
+
+        in_f.close()
+        return signature
+
+    # Bind all production function names to callable objects in pdict
+    def bind_callables(self,pdict):
+        for p in self.lr_productions:
+            p.bind(pdict)
+    
+# -----------------------------------------------------------------------------
+#                           === LR Generator ===
+#
+# The following classes and functions are used to generate LR parsing tables on 
+# a grammar.
+# -----------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
+# digraph()
+# traverse()
+#
+# The following two functions are used to compute set valued functions
+# of the form:
+#
+#     F(x) = F'(x) U U{F(y) | x R y}
+#
+# This is used to compute the values of Read() sets as well as FOLLOW sets
+# in LALR(1) generation.
+#
+# Inputs:  X    - An input set
+#          R    - A relation
+#          FP   - Set-valued function
+# ------------------------------------------------------------------------------
+
+def digraph(X,R,FP):
+    N = { }
+    for x in X:
+       N[x] = 0
+    stack = []
+    F = { }
+    for x in X:
+        if N[x] == 0: traverse(x,N,stack,F,X,R,FP)
+    return F
+
+def traverse(x,N,stack,F,X,R,FP):
+    stack.append(x)
+    d = len(stack)
+    N[x] = d
+    F[x] = FP(x)             # F(X) <- F'(x)
+
+    rel = R(x)               # Get y's related to x
+    for y in rel:
+        if N[y] == 0:
+             traverse(y,N,stack,F,X,R,FP)
+        N[x] = min(N[x],N[y])
+        for a in F.get(y,[]):
+            if a not in F[x]: F[x].append(a)
+    if N[x] == d:
+       N[stack[-1]] = MAXINT
+       F[stack[-1]] = F[x]
+       element = stack.pop()
+       while element != x:
+           N[stack[-1]] = MAXINT
+           F[stack[-1]] = F[x]
+           element = stack.pop()
+
+class LALRError(YaccError): pass
+
+# -----------------------------------------------------------------------------
+#                             == LRGeneratedTable ==
+#
+# This class implements the LR table generation algorithm.  There are no
+# public methods except for write()
+# -----------------------------------------------------------------------------
+
+class LRGeneratedTable(LRTable):
+    def __init__(self,grammar,method='LALR',log=None):
+        if method not in ['SLR','LALR']:
+            raise LALRError("Unsupported method %s" % method)
+
+        self.grammar = grammar
+        self.lr_method = method
+
+        # Set up the logger
+        if not log:
+            log = NullLogger()
+        self.log = log
+
+        # Internal attributes
+        self.lr_action     = {}        # Action table
+        self.lr_goto       = {}        # Goto table
+        self.lr_productions  = grammar.Productions    # Copy of grammar Production array
+        self.lr_goto_cache = {}        # Cache of computed gotos
+        self.lr0_cidhash   = {}        # Cache of closures
+
+        self._add_count    = 0         # Internal counter used to detect cycles
+
+        # Diagonistic information filled in by the table generator
+        self.sr_conflict   = 0
+        self.rr_conflict   = 0
+        self.conflicts     = []        # List of conflicts
+
+        self.sr_conflicts  = []
+        self.rr_conflicts  = []
+
+        # Build the tables
+        self.grammar.build_lritems()
+        self.grammar.compute_first()
+        self.grammar.compute_follow()
+        self.lr_parse_table()
+
+    # Compute the LR(0) closure operation on I, where I is a set of LR(0) items.
+
+    def lr0_closure(self,I):
+        self._add_count += 1
+
+        # Add everything in I to J
+        J = I[:]
+        didadd = 1
+        while didadd:
+            didadd = 0
+            for j in J:
+                for x in j.lr_after:
+                    if getattr(x,"lr0_added",0) == self._add_count: continue
+                    # Add B --> .G to J
+                    J.append(x.lr_next)
+                    x.lr0_added = self._add_count
+                    didadd = 1
+
+        return J
+
+    # Compute the LR(0) goto function goto(I,X) where I is a set
+    # of LR(0) items and X is a grammar symbol.   This function is written
+    # in a way that guarantees uniqueness of the generated goto sets
+    # (i.e. the same goto set will never be returned as two different Python
+    # objects).  With uniqueness, we can later do fast set comparisons using
+    # id(obj) instead of element-wise comparison.
+
+    def lr0_goto(self,I,x):
+        # First we look for a previously cached entry
+        g = self.lr_goto_cache.get((id(I),x))
+        if g: return g
+
+        # Now we generate the goto set in a way that guarantees uniqueness
+        # of the result
+
+        s = self.lr_goto_cache.get(x)
+        if not s:
+            s = { }
+            self.lr_goto_cache[x] = s
+
+        gs = [ ]
+        for p in I:
+            n = p.lr_next
+            if n and n.lr_before == x:
+                s1 = s.get(id(n))
+                if not s1:
+                    s1 = { }
+                    s[id(n)] = s1
+                gs.append(n)
+                s = s1
+        g = s.get('$end')
+        if not g:
+            if gs:
+                g = self.lr0_closure(gs)
+                s['$end'] = g
+            else:
+                s['$end'] = gs
+        self.lr_goto_cache[(id(I),x)] = g
+        return g
+
+    # Compute the LR(0) sets of item function
+    def lr0_items(self):
+
+        C = [ self.lr0_closure([self.grammar.Productions[0].lr_next]) ]
+        i = 0
+        for I in C:
+            self.lr0_cidhash[id(I)] = i
+            i += 1
+
+        # Loop over the items in C and each grammar symbols
+        i = 0
+        while i < len(C):
+            I = C[i]
+            i += 1
+
+            # Collect all of the symbols that could possibly be in the goto(I,X) sets
+            asyms = { }
+            for ii in I:
+                for s in ii.usyms:
+                    asyms[s] = None
+
+            for x in asyms:
+                g = self.lr0_goto(I,x)
+                if not g:  continue
+                if id(g) in self.lr0_cidhash: continue
+                self.lr0_cidhash[id(g)] = len(C)
+                C.append(g)
+
+        return C
+
+    # -----------------------------------------------------------------------------
+    #                       ==== LALR(1) Parsing ====
+    #
+    # LALR(1) parsing is almost exactly the same as SLR except that instead of
+    # relying upon Follow() sets when performing reductions, a more selective
+    # lookahead set that incorporates the state of the LR(0) machine is utilized.
+    # Thus, we mainly just have to focus on calculating the lookahead sets.
+    #
+    # The method used here is due to DeRemer and Pennelo (1982).
+    #
+    # DeRemer, F. L., and T. J. Pennelo: "Efficient Computation of LALR(1)
+    #     Lookahead Sets", ACM Transactions on Programming Languages and Systems,
+    #     Vol. 4, No. 4, Oct. 1982, pp. 615-649
+    #
+    # Further details can also be found in:
+    #
+    #  J. Tremblay and P. Sorenson, "The Theory and Practice of Compiler Writing",
+    #      McGraw-Hill Book Company, (1985).
+    #
+    # -----------------------------------------------------------------------------
+
+    # -----------------------------------------------------------------------------
+    # compute_nullable_nonterminals()
+    #
+    # Creates a dictionary containing all of the non-terminals that might produce
+    # an empty production.
+    # -----------------------------------------------------------------------------
+
+    def compute_nullable_nonterminals(self):
+        nullable = {}
+        num_nullable = 0
+        while 1:
+           for p in self.grammar.Productions[1:]:
+               if p.len == 0:
+                    nullable[p.name] = 1
+                    continue
+               for t in p.prod:
+                    if not t in nullable: break
+               else:
+                    nullable[p.name] = 1
+           if len(nullable) == num_nullable: break
+           num_nullable = len(nullable)
+        return nullable
+
+    # -----------------------------------------------------------------------------
+    # find_nonterminal_trans(C)
+    #
+    # Given a set of LR(0) items, this functions finds all of the non-terminal
+    # transitions.    These are transitions in which a dot appears immediately before
+    # a non-terminal.   Returns a list of tuples of the form (state,N) where state
+    # is the state number and N is the nonterminal symbol.
+    #
+    # The input C is the set of LR(0) items.
+    # -----------------------------------------------------------------------------
+
+    def find_nonterminal_transitions(self,C):
+         trans = []
+         for state in range(len(C)):
+             for p in C[state]:
+                 if p.lr_index < p.len - 1:
+                      t = (state,p.prod[p.lr_index+1])
+                      if t[1] in self.grammar.Nonterminals:
+                            if t not in trans: trans.append(t)
+             state = state + 1
+         return trans
+
+    # -----------------------------------------------------------------------------
+    # dr_relation()
+    #
+    # Computes the DR(p,A) relationships for non-terminal transitions.  The input
+    # is a tuple (state,N) where state is a number and N is a nonterminal symbol.
+    #
+    # Returns a list of terminals.
+    # -----------------------------------------------------------------------------
+
+    def dr_relation(self,C,trans,nullable):
+        dr_set = { }
+        state,N = trans
+        terms = []
+
+        g = self.lr0_goto(C[state],N)
+        for p in g:
+           if p.lr_index < p.len - 1:
+               a = p.prod[p.lr_index+1]
+               if a in self.grammar.Terminals:
+                   if a not in terms: terms.append(a)
+
+        # This extra bit is to handle the start state
+        if state == 0 and N == self.grammar.Productions[0].prod[0]:
+           terms.append('$end')
+
+        return terms
+
+    # -----------------------------------------------------------------------------
+    # reads_relation()
+    #
+    # Computes the READS() relation (p,A) READS (t,C).
+    # -----------------------------------------------------------------------------
+
+    def reads_relation(self,C, trans, empty):
+        # Look for empty transitions
+        rel = []
+        state, N = trans
+
+        g = self.lr0_goto(C[state],N)
+        j = self.lr0_cidhash.get(id(g),-1)
+        for p in g:
+            if p.lr_index < p.len - 1:
+                 a = p.prod[p.lr_index + 1]
+                 if a in empty:
+                      rel.append((j,a))
+
+        return rel
+
+    # -----------------------------------------------------------------------------
+    # compute_lookback_includes()
+    #
+    # Determines the lookback and includes relations
+    #
+    # LOOKBACK:
+    #
+    # This relation is determined by running the LR(0) state machine forward.
+    # For example, starting with a production "N : . A B C", we run it forward
+    # to obtain "N : A B C ."   We then build a relationship between this final
+    # state and the starting state.   These relationships are stored in a dictionary
+    # lookdict.
+    #
+    # INCLUDES:
+    #
+    # Computes the INCLUDE() relation (p,A) INCLUDES (p',B).
+    #
+    # This relation is used to determine non-terminal transitions that occur
+    # inside of other non-terminal transition states.   (p,A) INCLUDES (p', B)
+    # if the following holds:
+    #
+    #       B -> LAT, where T -> epsilon and p' -L-> p
+    #
+    # L is essentially a prefix (which may be empty), T is a suffix that must be
+    # able to derive an empty string.  State p' must lead to state p with the string L.
+    #
+    # -----------------------------------------------------------------------------
+
+    def compute_lookback_includes(self,C,trans,nullable):
+
+        lookdict = {}          # Dictionary of lookback relations
+        includedict = {}       # Dictionary of include relations
+
+        # Make a dictionary of non-terminal transitions
+        dtrans = {}
+        for t in trans:
+            dtrans[t] = 1
+
+        # Loop over all transitions and compute lookbacks and includes
+        for state,N in trans:
+            lookb = []
+            includes = []
+            for p in C[state]:
+                if p.name != N: continue
+
+                # Okay, we have a name match.  We now follow the production all the way
+                # through the state machine until we get the . on the right hand side
+
+                lr_index = p.lr_index
+                j = state
+                while lr_index < p.len - 1:
+                     lr_index = lr_index + 1
+                     t = p.prod[lr_index]
+
+                     # Check to see if this symbol and state are a non-terminal transition
+                     if (j,t) in dtrans:
+                           # Yes.  Okay, there is some chance that this is an includes relation
+                           # the only way to know for certain is whether the rest of the
+                           # production derives empty
+
+                           li = lr_index + 1
+                           while li < p.len:
+                                if p.prod[li] in self.grammar.Terminals: break      # No forget it
+                                if not p.prod[li] in nullable: break
+                                li = li + 1
+                           else:
+                                # Appears to be a relation between (j,t) and (state,N)
+                                includes.append((j,t))
+
+                     g = self.lr0_goto(C[j],t)               # Go to next set
+                     j = self.lr0_cidhash.get(id(g),-1)     # Go to next state
+
+                # When we get here, j is the final state, now we have to locate the production
+                for r in C[j]:
+                     if r.name != p.name: continue
+                     if r.len != p.len:   continue
+                     i = 0
+                     # This look is comparing a production ". A B C" with "A B C ."
+                     while i < r.lr_index:
+                          if r.prod[i] != p.prod[i+1]: break
+                          i = i + 1
+                     else:
+                          lookb.append((j,r))
+            for i in includes:
+                 if not i in includedict: includedict[i] = []
+                 includedict[i].append((state,N))
+            lookdict[(state,N)] = lookb
+
+        return lookdict,includedict
+
+    # -----------------------------------------------------------------------------
+    # compute_read_sets()
+    #
+    # Given a set of LR(0) items, this function computes the read sets.
+    #
+    # Inputs:  C        =  Set of LR(0) items
+    #          ntrans   = Set of nonterminal transitions
+    #          nullable = Set of empty transitions
+    #
+    # Returns a set containing the read sets
+    # -----------------------------------------------------------------------------
+
+    def compute_read_sets(self,C, ntrans, nullable):
+        FP = lambda x: self.dr_relation(C,x,nullable)
+        R =  lambda x: self.reads_relation(C,x,nullable)
+        F = digraph(ntrans,R,FP)
+        return F
+
+    # -----------------------------------------------------------------------------
+    # compute_follow_sets()
+    #
+    # Given a set of LR(0) items, a set of non-terminal transitions, a readset,
+    # and an include set, this function computes the follow sets
+    #
+    # Follow(p,A) = Read(p,A) U U {Follow(p',B) | (p,A) INCLUDES (p',B)}
+    #
+    # Inputs:
+    #            ntrans     = Set of nonterminal transitions
+    #            readsets   = Readset (previously computed)
+    #            inclsets   = Include sets (previously computed)
+    #
+    # Returns a set containing the follow sets
+    # -----------------------------------------------------------------------------
+
+    def compute_follow_sets(self,ntrans,readsets,inclsets):
+         FP = lambda x: readsets[x]
+         R  = lambda x: inclsets.get(x,[])
+         F = digraph(ntrans,R,FP)
+         return F
+
+    # -----------------------------------------------------------------------------
+    # add_lookaheads()
+    #
+    # Attaches the lookahead symbols to grammar rules.
+    #
+    # Inputs:    lookbacks         -  Set of lookback relations
+    #            followset         -  Computed follow set
+    #
+    # This function directly attaches the lookaheads to productions contained
+    # in the lookbacks set
+    # -----------------------------------------------------------------------------
+
+    def add_lookaheads(self,lookbacks,followset):
+        for trans,lb in lookbacks.items():
+            # Loop over productions in lookback
+            for state,p in lb:
+                 if not state in p.lookaheads:
+                      p.lookaheads[state] = []
+                 f = followset.get(trans,[])
+                 for a in f:
+                      if a not in p.lookaheads[state]: p.lookaheads[state].append(a)
+
+    # -----------------------------------------------------------------------------
+    # add_lalr_lookaheads()
+    #
+    # This function does all of the work of adding lookahead information for use
+    # with LALR parsing
+    # -----------------------------------------------------------------------------
+
+    def add_lalr_lookaheads(self,C):
+        # Determine all of the nullable nonterminals
+        nullable = self.compute_nullable_nonterminals()
+
+        # Find all non-terminal transitions
+        trans = self.find_nonterminal_transitions(C)
+
+        # Compute read sets
+        readsets = self.compute_read_sets(C,trans,nullable)
+
+        # Compute lookback/includes relations
+        lookd, included = self.compute_lookback_includes(C,trans,nullable)
+
+        # Compute LALR FOLLOW sets
+        followsets = self.compute_follow_sets(trans,readsets,included)
+
+        # Add all of the lookaheads
+        self.add_lookaheads(lookd,followsets)
+
+    # -----------------------------------------------------------------------------
+    # lr_parse_table()
+    #
+    # This function constructs the parse tables for SLR or LALR
+    # -----------------------------------------------------------------------------
+    def lr_parse_table(self):
+        Productions = self.grammar.Productions
+        Precedence  = self.grammar.Precedence
+        goto   = self.lr_goto         # Goto array
+        action = self.lr_action       # Action array
+        log    = self.log             # Logger for output
+
+        actionp = { }                 # Action production array (temporary)
+        
+        log.info("Parsing method: %s", self.lr_method)
+
+        # Step 1: Construct C = { I0, I1, ... IN}, collection of LR(0) items
+        # This determines the number of states
+
+        C = self.lr0_items()
+
+        if self.lr_method == 'LALR':
+            self.add_lalr_lookaheads(C)
+
+        # Build the parser table, state by state
+        st = 0
+        for I in C:
+            # Loop over each production in I
+            actlist = [ ]              # List of actions
+            st_action  = { }
+            st_actionp = { }
+            st_goto    = { }
+            log.info("")
+            log.info("state %d", st)
+            log.info("")
+            for p in I:
+                log.info("    (%d) %s", p.number, str(p))
+            log.info("")
+
+            for p in I:
+                    if p.len == p.lr_index + 1:
+                        if p.name == "S'":
+                            # Start symbol. Accept!
+                            st_action["$end"] = 0
+                            st_actionp["$end"] = p
+                        else:
+                            # We are at the end of a production.  Reduce!
+                            if self.lr_method == 'LALR':
+                                laheads = p.lookaheads[st]
+                            else:
+                                laheads = self.grammar.Follow[p.name]
+                            for a in laheads:
+                                actlist.append((a,p,"reduce using rule %d (%s)" % (p.number,p)))
+                                r = st_action.get(a)
+                                if r is not None:
+                                    # Whoa. Have a shift/reduce or reduce/reduce conflict
+                                    if r > 0:
+                                        # Need to decide on shift or reduce here
+                                        # By default we favor shifting. Need to add
+                                        # some precedence rules here.
+                                        sprec,slevel = Productions[st_actionp[a].number].prec
+                                        rprec,rlevel = Precedence.get(a,('right',0))
+                                        if (slevel < rlevel) or ((slevel == rlevel) and (rprec == 'left')):
+                                            # We really need to reduce here.
+                                            st_action[a] = -p.number
+                                            st_actionp[a] = p
+                                            if not slevel and not rlevel:
+                                                log.info("  ! shift/reduce conflict for %s resolved as reduce",a)
+                                                self.sr_conflicts.append((st,a,'reduce'))
+                                            Productions[p.number].reduced += 1
+                                        elif (slevel == rlevel) and (rprec == 'nonassoc'):
+                                            st_action[a] = None
+                                        else:
+                                            # Hmmm. Guess we'll keep the shift
+                                            if not rlevel:
+                                                log.info("  ! shift/reduce conflict for %s resolved as shift",a)
+                                                self.sr_conflicts.append((st,a,'shift'))
+                                    elif r < 0:
+                                        # Reduce/reduce conflict.   In this case, we favor the rule
+                                        # that was defined first in the grammar file
+                                        oldp = Productions[-r]
+                                        pp = Productions[p.number]
+                                        if oldp.line > pp.line:
+                                            st_action[a] = -p.number
+                                            st_actionp[a] = p
+                                            chosenp,rejectp = pp,oldp
+                                            Productions[p.number].reduced += 1
+                                            Productions[oldp.number].reduced -= 1
+                                        else:
+                                            chosenp,rejectp = oldp,pp
+                                        self.rr_conflicts.append((st,chosenp,rejectp))
+                                        log.info("  ! reduce/reduce conflict for %s resolved using rule %d (%s)", a,st_actionp[a].number, st_actionp[a])
+                                    else:
+                                        raise LALRError("Unknown conflict in state %d" % st)
+                                else:
+                                    st_action[a] = -p.number
+                                    st_actionp[a] = p
+                                    Productions[p.number].reduced += 1
+                    else:
+                        i = p.lr_index
+                        a = p.prod[i+1]       # Get symbol right after the "."
+                        if a in self.grammar.Terminals:
+                            g = self.lr0_goto(I,a)
+                            j = self.lr0_cidhash.get(id(g),-1)
+                            if j >= 0:
+                                # We are in a shift state
+                                actlist.append((a,p,"shift and go to state %d" % j))
+                                r = st_action.get(a)
+                                if r is not None:
+                                    # Whoa have a shift/reduce or shift/shift conflict
+                                    if r > 0:
+                                        if r != j:
+                                            raise LALRError("Shift/shift conflict in state %d" % st)
+                                    elif r < 0:
+                                        # Do a precedence check.
+                                        #   -  if precedence of reduce rule is higher, we reduce.
+                                        #   -  if precedence of reduce is same and left assoc, we reduce.
+                                        #   -  otherwise we shift
+                                        rprec,rlevel = Productions[st_actionp[a].number].prec
+                                        sprec,slevel = Precedence.get(a,('right',0))
+                                        if (slevel > rlevel) or ((slevel == rlevel) and (rprec == 'right')):
+                                            # We decide to shift here... highest precedence to shift
+                                            Productions[st_actionp[a].number].reduced -= 1
+                                            st_action[a] = j
+                                            st_actionp[a] = p
+                                            if not rlevel:
+                                                log.info("  ! shift/reduce conflict for %s resolved as shift",a)
+                                                self.sr_conflicts.append((st,a,'shift'))
+                                        elif (slevel == rlevel) and (rprec == 'nonassoc'):
+                                            st_action[a] = None
+                                        else:
+                                            # Hmmm. Guess we'll keep the reduce
+                                            if not slevel and not rlevel:
+                                                log.info("  ! shift/reduce conflict for %s resolved as reduce",a)
+                                                self.sr_conflicts.append((st,a,'reduce'))
+
+                                    else:
+                                        raise LALRError("Unknown conflict in state %d" % st)
+                                else:
+                                    st_action[a] = j
+                                    st_actionp[a] = p
+
+            # Print the actions associated with each terminal
+            _actprint = { }
+            for a,p,m in actlist:
+                if a in st_action:
+                    if p is st_actionp[a]:
+                        log.info("    %-15s %s",a,m)
+                        _actprint[(a,m)] = 1
+            log.info("")
+            # Print the actions that were not used. (debugging)
+            not_used = 0
+            for a,p,m in actlist:
+                if a in st_action:
+                    if p is not st_actionp[a]:
+                        if not (a,m) in _actprint:
+                            log.debug("  ! %-15s [ %s ]",a,m)
+                            not_used = 1
+                            _actprint[(a,m)] = 1
+            if not_used:
+                log.debug("")
+
+            # Construct the goto table for this state
+
+            nkeys = { }
+            for ii in I:
+                for s in ii.usyms:
+                    if s in self.grammar.Nonterminals:
+                        nkeys[s] = None
+            for n in nkeys:
+                g = self.lr0_goto(I,n)
+                j = self.lr0_cidhash.get(id(g),-1)
+                if j >= 0:
+                    st_goto[n] = j
+                    log.info("    %-30s shift and go to state %d",n,j)
+
+            action[st] = st_action
+            actionp[st] = st_actionp
+            goto[st] = st_goto
+            st += 1
+
+
+    # -----------------------------------------------------------------------------
+    # write()
+    #
+    # This function writes the LR parsing tables to a file
+    # -----------------------------------------------------------------------------
+
+    def write_table(self,modulename,outputdir='',signature=""):
+        basemodulename = modulename.split(".")[-1]
+        filename = os.path.join(outputdir,basemodulename) + ".py"
+        try:
+            f = open(filename,"w")
+
+            f.write("""
+# %s
+# This file is automatically generated. Do not edit.
+_tabversion = %r
+
+_lr_method = %r
+
+_lr_signature = %r
+    """ % (filename, __tabversion__, self.lr_method, signature))
+
+            # Change smaller to 0 to go back to original tables
+            smaller = 1
+
+            # Factor out names to try and make smaller
+            if smaller:
+                items = { }
+
+                for s,nd in self.lr_action.items():
+                   for name,v in nd.items():
+                      i = items.get(name)
+                      if not i:
+                         i = ([],[])
+                         items[name] = i
+                      i[0].append(s)
+                      i[1].append(v)
+
+                f.write("\n_lr_action_items = {")
+                for k,v in items.items():
+                    f.write("%r:([" % k)
+                    for i in v[0]:
+                        f.write("%r," % i)
+                    f.write("],[")
+                    for i in v[1]:
+                        f.write("%r," % i)
+
+                    f.write("]),")
+                f.write("}\n")
+
+                f.write("""
+_lr_action = { }
+for _k, _v in _lr_action_items.items():
+   for _x,_y in zip(_v[0],_v[1]):
+      if not _x in _lr_action:  _lr_action[_x] = { }
+      _lr_action[_x][_k] = _y
+del _lr_action_items
+""")
+
+            else:
+                f.write("\n_lr_action = { ");
+                for k,v in self.lr_action.items():
+                    f.write("(%r,%r):%r," % (k[0],k[1],v))
+                f.write("}\n");
+
+            if smaller:
+                # Factor out names to try and make smaller
+                items = { }
+
+                for s,nd in self.lr_goto.items():
+                   for name,v in nd.items():
+                      i = items.get(name)
+                      if not i:
+                         i = ([],[])
+                         items[name] = i
+                      i[0].append(s)
+                      i[1].append(v)
+
+                f.write("\n_lr_goto_items = {")
+                for k,v in items.items():
+                    f.write("%r:([" % k)
+                    for i in v[0]:
+                        f.write("%r," % i)
+                    f.write("],[")
+                    for i in v[1]:
+                        f.write("%r," % i)
+
+                    f.write("]),")
+                f.write("}\n")
+
+                f.write("""
+_lr_goto = { }
+for _k, _v in _lr_goto_items.items():
+   for _x,_y in zip(_v[0],_v[1]):
+       if not _x in _lr_goto: _lr_goto[_x] = { }
+       _lr_goto[_x][_k] = _y
+del _lr_goto_items
+""")
+            else:
+                f.write("\n_lr_goto = { ");
+                for k,v in self.lr_goto.items():
+                    f.write("(%r,%r):%r," % (k[0],k[1],v))
+                f.write("}\n");
+
+            # Write production table
+            f.write("_lr_productions = [\n")
+            for p in self.lr_productions:
+                if p.func:
+                    f.write("  (%r,%r,%d,%r,%r,%d),\n" % (p.str,p.name, p.len, p.func,p.file,p.line))
+                else:
+                    f.write("  (%r,%r,%d,None,None,None),\n" % (str(p),p.name, p.len))
+            f.write("]\n")
+            f.close()
+
+        except IOError:
+            e = sys.exc_info()[1]
+            sys.stderr.write("Unable to create %r\n" % filename)
+            sys.stderr.write(str(e)+"\n")
+            return
+
+
+    # -----------------------------------------------------------------------------
+    # pickle_table()
+    #
+    # This function pickles the LR parsing tables to a supplied file object
+    # -----------------------------------------------------------------------------
+
+    def pickle_table(self,filename,signature=""):
+        try:
+            import cPickle as pickle
+        except ImportError:
+            import pickle
+        outf = open(filename,"wb")
+        pickle.dump(__tabversion__,outf,pickle_protocol)
+        pickle.dump(self.lr_method,outf,pickle_protocol)
+        pickle.dump(signature,outf,pickle_protocol)
+        pickle.dump(self.lr_action,outf,pickle_protocol)
+        pickle.dump(self.lr_goto,outf,pickle_protocol)
+
+        outp = []
+        for p in self.lr_productions:
+            if p.func:
+                outp.append((p.str,p.name, p.len, p.func,p.file,p.line))
+            else:
+                outp.append((str(p),p.name,p.len,None,None,None))
+        pickle.dump(outp,outf,pickle_protocol)
+        outf.close()
+
+# -----------------------------------------------------------------------------
+#                            === INTROSPECTION ===
+#
+# The following functions and classes are used to implement the PLY
+# introspection features followed by the yacc() function itself.
+# -----------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
+# 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
+
+# -----------------------------------------------------------------------------
+# parse_grammar()
+#
+# This takes a raw grammar rule string and parses it into production data
+# -----------------------------------------------------------------------------
+def parse_grammar(doc,file,line):
+    grammar = []
+    # Split the doc string into lines
+    pstrings = doc.splitlines()
+    lastp = None
+    dline = line
+    for ps in pstrings:
+        dline += 1
+        p = ps.split()
+        if not p: continue
+        try:
+            if p[0] == '|':
+                # This is a continuation of a previous rule
+                if not lastp:
+                    raise SyntaxError("%s:%d: Misplaced '|'" % (file,dline))
+                prodname = lastp
+                syms = p[1:]
+            else:
+                prodname = p[0]
+                lastp = prodname
+                syms   = p[2:]
+                assign = p[1]
+                if assign != ':' and assign != '::=':
+                    raise SyntaxError("%s:%d: Syntax error. Expected ':'" % (file,dline))
+
+            grammar.append((file,dline,prodname,syms))
+        except SyntaxError:
+            raise
+        except Exception:
+            raise SyntaxError("%s:%d: Syntax error in rule %r" % (file,dline,ps.strip()))
+
+    return grammar
+
+# -----------------------------------------------------------------------------
+# ParserReflect()
+#
+# This class represents information extracted for building a parser including
+# start symbol, error function, tokens, precedence list, action functions,
+# etc.
+# -----------------------------------------------------------------------------
+class ParserReflect(object):
+    def __init__(self,pdict,log=None):
+        self.pdict      = pdict
+        self.start      = None
+        self.error_func = None
+        self.tokens     = None
+        self.modules    = {}
+        self.grammar    = []
+        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_start()
+        self.get_error_func()
+        self.get_tokens()
+        self.get_precedence()
+        self.get_pfunctions()
+        
+    # Validate all of the information
+    def validate_all(self):
+        self.validate_start()
+        self.validate_error_func()
+        self.validate_tokens()
+        self.validate_precedence()
+        self.validate_pfunctions()
+        self.validate_modules()
+        return self.error
+
+    # Compute a signature over the grammar
+    def signature(self):
+        try:
+            from hashlib import md5
+        except ImportError:
+            from md5 import md5
+        try:
+            sig = md5()
+            if self.start:
+                sig.update(self.start.encode('latin-1'))
+            if self.prec:
+                sig.update("".join(["".join(p) for p in self.prec]).encode('latin-1'))
+            if self.tokens:
+                sig.update(" ".join(self.tokens).encode('latin-1'))
+            for f in self.pfuncs:
+                if f[3]:
+                    sig.update(f[3].encode('latin-1'))
+        except (TypeError,ValueError):
+            pass
+        return sig.digest()
+
+    # -----------------------------------------------------------------------------
+    # validate_modules()
+    #
+    # This method checks to see if there are duplicated p_rulename() functions
+    # in the parser module file.  Without this function, it is really easy for
+    # users to make mistakes by cutting and pasting code fragments (and it's a real
+    # bugger to try and figure out why the resulting parser doesn't work).  Therefore,
+    # we just do a little regular expression pattern matching of def statements
+    # to try and detect duplicates.
+    # -----------------------------------------------------------------------------
+
+    def validate_modules(self):
+        # Match def p_funcname(
+        fre = re.compile(r'\s*def\s+(p_[a-zA-Z_0-9]*)\(')
+
+        for module in self.modules.keys():
+            lines, linen = inspect.getsourcelines(module)
+
+            counthash = { }
+            for linen,l in enumerate(lines):
+                linen += 1
+                m = fre.match(l)
+                if m:
+                    name = m.group(1)
+                    prev = counthash.get(name)
+                    if not prev:
+                        counthash[name] = linen
+                    else:
+                        filename = inspect.getsourcefile(module)
+                        self.log.warning("%s:%d: Function %s redefined. Previously defined on line %d", filename,linen,name,prev)
+
+    # Get the start symbol
+    def get_start(self):
+        self.start = self.pdict.get('start')
+
+    # Validate the start symbol
+    def validate_start(self):
+        if self.start is not None:
+            if not isinstance(self.start, string_types):
+                self.log.error("'start' must be a string")
+
+    # Look for error handler
+    def get_error_func(self):
+        self.error_func = self.pdict.get('p_error')
+
+    # Validate the error function
+    def validate_error_func(self):
+        if self.error_func:
+            if isinstance(self.error_func,types.FunctionType):
+                ismethod = 0
+            elif isinstance(self.error_func, types.MethodType):
+                ismethod = 1
+            else:
+                self.log.error("'p_error' defined, but is not a function or method")
+                self.error = 1
+                return
+
+            eline = func_code(self.error_func).co_firstlineno
+            efile = func_code(self.error_func).co_filename
+            module = inspect.getmodule(self.error_func)
+            self.modules[module] = 1
+
+            argcount = func_code(self.error_func).co_argcount - ismethod
+            if argcount != 1:
+                self.log.error("%s:%d: p_error() requires 1 argument",efile,eline)
+                self.error = 1
+
+    # Get the tokens map
+    def get_tokens(self):
+        tokens = self.pdict.get("tokens")
+        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):
+        # Validate the tokens.
+        if 'error' in self.tokens:
+            self.log.error("Illegal token name 'error'. Is a reserved word")
+            self.error = 1
+            return
+
+        terminals = {}
+        for n in self.tokens:
+            if n in terminals:
+                self.log.warning("Token %r multiply defined", n)
+            terminals[n] = 1
+
+    # Get the precedence map (if any)
+    def get_precedence(self):
+        self.prec = self.pdict.get("precedence")
+
+    # Validate and parse the precedence map
+    def validate_precedence(self):
+        preclist = []
+        if self.prec:
+            if not isinstance(self.prec,(list,tuple)):
+                self.log.error("precedence must be a list or tuple")
+                self.error = 1
+                return
+            for level,p in enumerate(self.prec):
+                if not isinstance(p,(list,tuple)):
+                    self.log.error("Bad precedence table")
+                    self.error = 1
+                    return
+
+                if len(p) < 2:
+                    self.log.error("Malformed precedence entry %s. Must be (assoc, term, ..., term)",p)
+                    self.error = 1
+                    return
+                assoc = p[0]
+                if not isinstance(assoc, string_types):
+                    self.log.error("precedence associativity must be a string")
+                    self.error = 1
+                    return
+                for term in p[1:]:
+                    if not isinstance(term, string_types):
+                        self.log.error("precedence items must be strings")
+                        self.error = 1
+                        return
+                    preclist.append((term, assoc, level+1))
+        self.preclist = preclist
+
+    # Get all p_functions from the grammar
+    def get_pfunctions(self):
+        p_functions = []
+        for name, item in self.pdict.items():
+            if not name.startswith('p_'): continue
+            if name == 'p_error': continue
+            if isinstance(item,(types.FunctionType,types.MethodType)):
+                line = func_code(item).co_firstlineno
+                module = inspect.getmodule(item)
+                p_functions.append((line,module,name,item.__doc__))
+
+        # Sort all of the actions by line number
+        p_functions.sort()
+        self.pfuncs = p_functions
+
+
+    # Validate all of the p_functions
+    def validate_pfunctions(self):
+        grammar = []
+        # Check for non-empty symbols
+        if len(self.pfuncs) == 0:
+            self.log.error("no rules of the form p_rulename are defined")
+            self.error = 1
+            return
+
+        for line, module, name, doc in self.pfuncs:
+            file = inspect.getsourcefile(module)
+            func = self.pdict[name]
+            if isinstance(func, types.MethodType):
+                reqargs = 2
+            else:
+                reqargs = 1
+            if func_code(func).co_argcount > reqargs:
+                self.log.error("%s:%d: Rule %r has too many arguments",file,line,func.__name__)
+                self.error = 1
+            elif func_code(func).co_argcount < reqargs:
+                self.log.error("%s:%d: Rule %r requires an argument",file,line,func.__name__)
+                self.error = 1
+            elif not func.__doc__:
+                self.log.warning("%s:%d: No documentation string specified in function %r (ignored)",file,line,func.__name__)
+            else:
+                try:
+                    parsed_g = parse_grammar(doc,file,line)
+                    for g in parsed_g:
+                        grammar.append((name, g))
+                except SyntaxError:
+                    e = sys.exc_info()[1]
+                    self.log.error(str(e))
+                    self.error = 1
+
+                # Looks like a valid grammar rule
+                # Mark the file in which defined.
+                self.modules[module] = 1
+
+        # Secondary validation step that looks for p_ definitions that are not functions
+        # or functions that look like they might be grammar rules.
+
+        for n,v in self.pdict.items():
+            if n.startswith('p_') and isinstance(v, (types.FunctionType, types.MethodType)): continue
+            if n.startswith('t_'): continue
+            if n.startswith('p_') and n != 'p_error':
+                self.log.warning("%r not defined as a function", n)
+            if ((isinstance(v,types.FunctionType) and func_code(v).co_argcount == 1) or
+                (isinstance(v,types.MethodType) and func_code(v).co_argcount == 2)):
+                try:
+                    doc = v.__doc__.split(" ")
+                    if doc[1] == ':':
+                        self.log.warning("%s:%d: Possible grammar rule %r defined without p_ prefix",
+                                         func_code(v).co_filename, func_code(v).co_firstlineno,n)
+                except Exception:
+                    pass
+
+        self.grammar = grammar
+
+# -----------------------------------------------------------------------------
+# yacc(module)
+#
+# Build a parser
+# -----------------------------------------------------------------------------
+
+def yacc(method='LALR', debug=yaccdebug, module=None, tabmodule=tab_module, start=None, 
+         check_recursion=1, optimize=0, write_tables=1, debugfile=debug_file,outputdir='',
+         debuglog=None, errorlog = None, picklefile=None):
+
+    global parse                 # Reference to the parsing method of the last built parser
+
+    # If pickling is enabled, table files are not created
+
+    if picklefile:
+        write_tables = 0
+
+    if errorlog is None:
+        errorlog = PlyLogger(sys.stderr)
+
+    # Get the module dictionary used for the parser
+    if module:
+        _items = [(k,getattr(module,k)) for k in dir(module)]
+        pdict = dict(_items)
+    else:
+        pdict = get_caller_module_dict(2)
+
+    # Collect parser information from the dictionary
+    pinfo = ParserReflect(pdict,log=errorlog)
+    pinfo.get_all()
+
+    if pinfo.error:
+        raise YaccError("Unable to build parser")
+
+    # Check signature against table files (if any)
+    signature = pinfo.signature()
+
+    # Read the tables
+    try:
+        lr = LRTable()
+        if picklefile:
+            read_signature = lr.read_pickle(picklefile)
+        else:
+            read_signature = lr.read_table(tabmodule)
+        if optimize or (read_signature == signature):
+            try:
+                lr.bind_callables(pinfo.pdict)
+                parser = LRParser(lr,pinfo.error_func)
+                parse = parser.parse
+                return parser
+            except Exception:
+                e = sys.exc_info()[1]
+                errorlog.warning("There was a problem loading the table file: %s", repr(e))
+    except VersionError:
+        e = sys.exc_info()
+        errorlog.warning(str(e))
+    except Exception:
+        pass
+
+    if debuglog is None:
+        if debug:
+            debuglog = PlyLogger(open(debugfile,"w"))
+        else:
+            debuglog = NullLogger()
+
+    debuglog.info("Created by PLY version %s (http://www.dabeaz.com/ply)", __version__)
+
+
+    errors = 0
+
+    # Validate the parser information
+    if pinfo.validate_all():
+        raise YaccError("Unable to build parser")
+    
+    if not pinfo.error_func:
+        errorlog.warning("no p_error() function is defined")
+
+    # Create a grammar object
+    grammar = Grammar(pinfo.tokens)
+
+    # Set precedence level for terminals
+    for term, assoc, level in pinfo.preclist:
+        try:
+            grammar.set_precedence(term,assoc,level)
+        except GrammarError:
+            e = sys.exc_info()[1]
+            errorlog.warning("%s",str(e))
+
+    # Add productions to the grammar
+    for funcname, gram in pinfo.grammar:
+        file, line, prodname, syms = gram
+        try:
+            grammar.add_production(prodname,syms,funcname,file,line)
+        except GrammarError:
+            e = sys.exc_info()[1]
+            errorlog.error("%s",str(e))
+            errors = 1
+
+    # Set the grammar start symbols
+    try:
+        if start is None:
+            grammar.set_start(pinfo.start)
+        else:
+            grammar.set_start(start)
+    except GrammarError:
+        e = sys.exc_info()[1]
+        errorlog.error(str(e))
+        errors = 1
+
+    if errors:
+        raise YaccError("Unable to build parser")
+
+    # Verify the grammar structure
+    undefined_symbols = grammar.undefined_symbols()
+    for sym, prod in undefined_symbols:
+        errorlog.error("%s:%d: Symbol %r used, but not defined as a token or a rule",prod.file,prod.line,sym)
+        errors = 1
+
+    unused_terminals = grammar.unused_terminals()
+    if unused_terminals:
+        debuglog.info("")
+        debuglog.info("Unused terminals:")
+        debuglog.info("")
+        for term in unused_terminals:
+            errorlog.warning("Token %r defined, but not used", term)
+            debuglog.info("    %s", term)
+
+    # Print out all productions to the debug log
+    if debug:
+        debuglog.info("")
+        debuglog.info("Grammar")
+        debuglog.info("")
+        for n,p in enumerate(grammar.Productions):
+            debuglog.info("Rule %-5d %s", n, p)
+
+    # Find unused non-terminals
+    unused_rules = grammar.unused_rules()
+    for prod in unused_rules:
+        errorlog.warning("%s:%d: Rule %r defined, but not used", prod.file, prod.line, prod.name)
+
+    if len(unused_terminals) == 1:
+        errorlog.warning("There is 1 unused token")
+    if len(unused_terminals) > 1:
+        errorlog.warning("There are %d unused tokens", len(unused_terminals))
+
+    if len(unused_rules) == 1:
+        errorlog.warning("There is 1 unused rule")
+    if len(unused_rules) > 1:
+        errorlog.warning("There are %d unused rules", len(unused_rules))
+
+    if debug:
+        debuglog.info("")
+        debuglog.info("Terminals, with rules where they appear")
+        debuglog.info("")
+        terms = list(grammar.Terminals)
+        terms.sort()
+        for term in terms:
+            debuglog.info("%-20s : %s", term, " ".join([str(s) for s in grammar.Terminals[term]]))
+        
+        debuglog.info("")
+        debuglog.info("Nonterminals, with rules where they appear")
+        debuglog.info("")
+        nonterms = list(grammar.Nonterminals)
+        nonterms.sort()
+        for nonterm in nonterms:
+            debuglog.info("%-20s : %s", nonterm, " ".join([str(s) for s in grammar.Nonterminals[nonterm]]))
+        debuglog.info("")
+
+    if check_recursion:
+        unreachable = grammar.find_unreachable()
+        for u in unreachable:
+            errorlog.warning("Symbol %r is unreachable",u)
+
+        infinite = grammar.infinite_cycles()
+        for inf in infinite:
+            errorlog.error("Infinite recursion detected for symbol %r", inf)
+            errors = 1
+        
+    unused_prec = grammar.unused_precedence()
+    for term, assoc in unused_prec:
+        errorlog.error("Precedence rule %r defined for unknown symbol %r", assoc, term)
+        errors = 1
+
+    if errors:
+        raise YaccError("Unable to build parser")
+    
+    # Run the LRGeneratedTable on the grammar
+    if debug:
+        errorlog.debug("Generating %s tables", method)
+            
+    lr = LRGeneratedTable(grammar,method,debuglog)
+
+    if debug:
+        num_sr = len(lr.sr_conflicts)
+
+        # Report shift/reduce and reduce/reduce conflicts
+        if num_sr == 1:
+            errorlog.warning("1 shift/reduce conflict")
+        elif num_sr > 1:
+            errorlog.warning("%d shift/reduce conflicts", num_sr)
+
+        num_rr = len(lr.rr_conflicts)
+        if num_rr == 1:
+            errorlog.warning("1 reduce/reduce conflict")
+        elif num_rr > 1:
+            errorlog.warning("%d reduce/reduce conflicts", num_rr)
+
+    # Write out conflicts to the output file
+    if debug and (lr.sr_conflicts or lr.rr_conflicts):
+        debuglog.warning("")
+        debuglog.warning("Conflicts:")
+        debuglog.warning("")
+
+        for state, tok, resolution in lr.sr_conflicts:
+            debuglog.warning("shift/reduce conflict for %s in state %d resolved as %s",  tok, state, resolution)
+        
+        already_reported = {}
+        for state, rule, rejected in lr.rr_conflicts:
+            if (state,id(rule),id(rejected)) in already_reported:
+                continue
+            debuglog.warning("reduce/reduce conflict in state %d resolved using rule (%s)", state, rule)
+            debuglog.warning("rejected rule (%s) in state %d", rejected,state)
+            errorlog.warning("reduce/reduce conflict in state %d resolved using rule (%s)", state, rule)
+            errorlog.warning("rejected rule (%s) in state %d", rejected, state)
+            already_reported[state,id(rule),id(rejected)] = 1
+        
+        warned_never = []
+        for state, rule, rejected in lr.rr_conflicts:
+            if not rejected.reduced and (rejected not in warned_never):
+                debuglog.warning("Rule (%s) is never reduced", rejected)
+                errorlog.warning("Rule (%s) is never reduced", rejected)
+                warned_never.append(rejected)
+
+    # Write the table file if requested
+    if write_tables:
+        lr.write_table(tabmodule,outputdir,signature)
+
+    # Write a pickled version of the tables
+    if picklefile:
+        lr.pickle_table(picklefile,signature)
+
+    # Build the parser
+    lr.bind_callables(pinfo.pdict)
+    parser = LRParser(lr,pinfo.error_func)
+
+    parse = parser.parse
+    return parser
diff --git a/plyproto/__init__.py b/plyproto/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/plyproto/__init__.py
diff --git a/plyproto/model.py b/plyproto/model.py
new file mode 100644
index 0000000..7e39ae9
--- /dev/null
+++ b/plyproto/model.py
@@ -0,0 +1,218 @@
+__author__ = "Dusan (Ph4r05) Klinec"
+__copyright__ = "Copyright (C) 2014 Dusan (ph4r05) Klinec"
+__license__ = "Apache License, Version 2.0"
+__version__ = "1.0"
+
+# Base node
+class SourceElement(object):
+    '''
+    A SourceElement is the base class for all elements that occur in a Java
+    file parsed by plyj.
+    '''
+    def __init__(self):
+        super(SourceElement, self).__init__()
+        self._fields = []
+
+    def __repr__(self):
+        equals = ("{0}={1!r}".format(k, getattr(self, k))
+                  for k in self._fields)
+        args = ", ".join(equals)
+        return "{0}({1})".format(self.__class__.__name__, args)
+
+    def __eq__(self, other):
+        try:
+            return self.__dict__ == other.__dict__
+        except AttributeError:
+            return False
+
+    def __ne__(self, other):
+        return not self == other
+
+    def accept(self, visitor):
+        pass
+
+class PackageDeclaration(SourceElement):
+    def __init__(self, name):
+        super(PackageDeclaration, self).__init__()
+        self._fields = ['name']
+        self.name = name
+
+    def accept(self, visitor):
+        visitor.visit_PackageDeclaration(self)
+
+class ImportStatement(SourceElement):
+    def __init__(self, name):
+        super(ImportStatement, self).__init__()
+        self._fields = ['name']
+        self.name = name
+
+    def accept(self, visitor):
+        visitor.visit_ImportStatement(self)
+
+class OptionDefinition(SourceElement):
+    def __init__(self, name, value):
+        super(OptionDefinition, self).__init__()
+        self._fields = ['name', 'value']
+        self.name = name
+        self.value = value
+
+    def accept(self, visitor):
+        visitor.visit_OptionDefinition(self)
+
+class FieldDirectiveDeclaration(SourceElement):
+    def __init__(self, name, value):
+        super(FieldDirectiveDeclaration, self).__init__()
+        self._fields = ['name', 'value']
+        self.name = name
+        self.value = value
+
+    def accept(self, visitor):
+        visitor.visit_FieldDirectiveDeclaration(self)
+
+class FieldPrimitiveType(SourceElement):
+    def __init__(self, name):
+        super(FieldPrimitiveType, self).__init__()
+        self._fields = ['name']
+        self.name = name
+
+    def accept(self, visitor):
+        visitor.visit_FieldPrimitiveType(self)
+
+class FieldDeclaration(SourceElement):
+    def __init__(self, field_modifier, ftype, name, fieldId, fieldDirective):
+        super(FieldDeclaration, self).__init__()
+        self._fields = ['field_modifier', 'ftype', 'name', 'fieldId', 'fieldDirective']
+        self.name = name
+        self.field_modifier = field_modifier
+        self.ftype = ftype
+        self.fieldId = fieldId
+        self.fieldDirective = fieldDirective
+
+    def accept(self, visitor):
+        visitor.visit_FieldDeclaration(self)
+
+class EnumFieldDeclaration(SourceElement):
+    def __init__(self, name, fieldId):
+        super(EnumFieldDeclaration, self).__init__()
+        self._fields = ['name', 'fieldId']
+        self.name = name
+        self.fieldId = fieldId
+
+    def accept(self, visitor):
+        visitor.visit_EnumFieldDeclaration(self)
+
+class EnumDeclaration(SourceElement):
+    def __init__(self, name, body):
+        super(EnumDeclaration, self).__init__()
+        self._fields = ['name', 'body']
+        self.name = name
+        self.body = body
+
+    def accept(self, visitor):
+        if visitor.visit_EnumDeclaration(self):
+            for s in self.body:
+                s.accept(visitor)
+
+class MessageDeclaration(SourceElement):
+    def __init__(self, name, body):
+        super(MessageDeclaration, self).__init__()
+        self._fields = ['name', 'body']
+        self.name = name
+        self.body = body
+
+    def accept(self, visitor):
+        if visitor.visit_MessageDeclaration(self):
+            for s in self.body:
+                s.accept(visitor)
+
+class MessageExtension(SourceElement):
+    def __init__(self, name, body):
+        super(MessageExtension, self).__init__()
+        self._fields = ['name', 'body']
+        self.name = name
+        self.body = body
+
+    def accept(self, visitor):
+        if visitor.visit_MessageExtension(self):
+            for s in self.body:
+                s.accept(visitor)
+
+class MethodDefinition(SourceElement):
+    def __init__(self, name, name2, name3):
+        super(MethodDefinition, self).__init__()
+        self._fields = ['name', 'name2', 'name3']
+        self.name = name
+        self.name2 = name2
+        self.name3 = name3
+
+    def accept(self, visitor):
+        visitor.visit_MethodDefinition(self)
+
+class ServiceDeclaration(SourceElement):
+    def __init__(self, name, body):
+        super(ServiceDeclaration, self).__init__()
+        self._fields = ['name', 'body']
+        self.name = name
+        self.body = body
+
+    def accept(self, visitor):
+        if visitor.visit_ServiceDeclaration(self):
+            for s in self.body:
+                s.accept(visitor)
+
+class ExtensionsMax(SourceElement):
+    pass
+
+class ExtensionsDirective(SourceElement):
+    def __init__(self, fromVal, toVal):
+        super(ExtensionsDirective, self).__init__()
+        self._fields = ['fromVal', 'toVal']
+        self.fromVal = fromVal
+        self.toVal = toVal
+
+    def accept(self, visitor):
+        visitor.visit_ExtensionsDirective(self)
+
+class Literal(SourceElement):
+
+    def __init__(self, value):
+        super(Literal, self).__init__()
+        self._fields = ['value']
+        self.value = value
+
+    def accept(self, visitor):
+        visitor.visit_Literal(self)
+
+class Name(SourceElement):
+
+    def __init__(self, value):
+        super(Name, self).__init__()
+        self._fields = ['value']
+        self.value = value
+
+    def append_name(self, name):
+        try:
+            self.value = self.value + '.' + name.value
+        except:
+            self.value = self.value + '.' + name
+
+    def accept(self, visitor):
+        visitor.visit_Name(self)
+
+
+class Visitor(object):
+
+    def __init__(self, verbose=False):
+        self.verbose = verbose
+
+    def __getattr__(self, name):
+        if not name.startswith('visit_'):
+            raise AttributeError('name must start with visit_ but was {}'
+                                 .format(name))
+
+        def f(element):
+            if self.verbose:
+                msg = 'unimplemented call to {}; ignoring ({})'
+                print(msg.format(name, element))
+            return True
+        return f
diff --git a/plyproto/parser.py b/plyproto/parser.py
new file mode 100755
index 0000000..545faee
--- /dev/null
+++ b/plyproto/parser.py
@@ -0,0 +1,335 @@
+__author__ = "Dusan (Ph4r05) Klinec"
+__copyright__ = "Copyright (C) 2014 Dusan (ph4r05) Klinec"
+__license__ = "Apache License, Version 2.0"
+__version__ = "1.0"
+
+import ply.lex as lex
+import ply.yacc as yacc
+from .model import *
+
+class ProtobufLexer(object):
+    keywords = ('double', 'float', 'int32', 'int64', 'uint32', 'uint64', 'sint32', 'sint64',
+                'fixed32', 'fixed64', 'sfixed32', 'sfixed64', 'bool', 'string', 'bytes',
+                'message', 'required', 'optional', 'repeated', 'enum', 'extensions', 'max', 'extends', 'extend',
+                'to', 'package', 'service', 'rpc', 'returns', 'true', 'false', 'option', 'import')
+
+    tokens = [
+        'NAME',
+        'NUM',
+        'STRING_LITERAL',
+        'LINE_COMMENT', 'BLOCK_COMMENT',
+
+        'LBRACE', 'RBRACE', 'LBRACK', 'RBRACK',
+        'LPAR', 'RPAR', 'EQ', 'SEMI'
+
+    ] + [k.upper() for k in keywords]
+    literals = '()+-*/=?:,.^|&~!=[]{};<>@%'
+
+    t_NUM = r'[+-]?\d+'
+    t_STRING_LITERAL = r'\"([^\\\n]|(\\.))*?\"'
+
+    t_ignore_LINE_COMMENT = '//.*'
+    def t_BLOCK_COMMENT(self, t):
+        r'/\*(.|\n)*?\*/'
+        t.lexer.lineno += t.value.count('\n')
+
+    t_LBRACE = '{'
+    t_RBRACE = '}'
+    t_LBRACK = '\\['
+    t_RBRACK = '\\]'
+    t_LPAR = '\\('
+    t_RPAR = '\\)'
+    t_EQ = '='
+    t_SEMI = ';'
+    t_ignore = ' \t\f'
+
+    def t_NAME(self, t):
+        '[A-Za-z_$][A-Za-z0-9_$]*'
+        if t.value in ProtobufLexer.keywords:
+            t.type = t.value.upper()
+        return t
+
+    def t_newline(self, t):
+        r'\n+'
+        t.lexer.lineno += len(t.value)
+
+    def t_newline2(self, t):
+        r'(\r\n)+'
+        t.lexer.lineno += len(t.value) / 2
+
+    def t_error(self, t):
+        print("Illegal character '{}' ({}) in line {}".format(t.value[0], hex(ord(t.value[0])), t.lexer.lineno))
+        t.lexer.skip(1)
+
+class ProtobufParser(object):
+    tokens = ProtobufLexer.tokens
+
+    def p_empty(self, p):
+        '''empty :'''
+        pass
+
+    def p_field_modifier(self,p):
+        '''field_modifier : REQUIRED
+                          | OPTIONAL
+                          | REPEATED'''
+        p[0] = p[1]
+
+    def p_primitive_type(self, p):
+        '''primitive_type : DOUBLE
+                          | FLOAT
+                          | INT32
+                          | INT64
+                          | UINT32
+                          | UINT64
+                          | SINT32
+                          | SINT64
+                          | FIXED32
+                          | FIXED64
+                          | SFIXED32
+                          | SFIXED64
+                          | BOOL
+                          | STRING
+                          | BYTES'''
+        p[0] = p[1]
+
+    def p_field_id(self, p):
+        '''field_id : NUM'''
+        p[0] = p[1]
+
+    def p_rvalue(self, p):
+        '''rvalue : NUM
+                  | TRUE
+                  | FALSE'''
+        p[0] = p[1]
+
+    def p_rvalue2(self, p):
+        '''rvalue : NAME'''
+        p[0] = Name(p[1])
+
+    def p_field_directive(self, p):
+        '''field_directive : LBRACK NAME EQ rvalue RBRACK'''
+        p[0] = FieldDirectiveDeclaration(Name(p[2]), p[4])
+
+    def p_field_directive_times(self, p):
+        '''field_directive_times : field_directive_plus'''
+        p[0] = p[1]
+
+    def p_field_directive_times2(self, p):
+        '''field_directive_times : empty'''
+        p[0] = []
+
+    def p_field_directive_plus(self, p):
+        '''field_directive_plus : field_directive
+                               | field_directive_plus field_directive'''
+        if len(p) == 2:
+            p[0] = [p[1]]
+        else:
+            p[0] = p[1] + [p[2]]
+
+    def p_field_type(self, p):
+        '''field_type : primitive_type'''
+        p[0] = FieldPrimitiveType(p[1])
+
+    def p_field_type2(self, p):
+        '''field_type : NAME'''
+        p[0] = Name(p[1])
+
+    # Root of the field declaration.
+    def p_field_definition(self, p):
+        '''field_definition : field_modifier field_type NAME EQ field_id field_directive_times SEMI'''
+        p[0] = FieldDeclaration(p[1], p[2], Name(p[3]), p[5], p[6])
+
+    # Root of the enum field declaration.
+    def p_enum_field(self, p):
+        '''enum_field : NAME EQ NUM SEMI'''
+        p[0] = EnumFieldDeclaration(Name(p[1]), p[3])
+
+    def p_enum_body_part(self, p):
+        '''enum_body_part : enum_field
+                          | option_directive'''
+        p[0] = p[1]
+
+    def p_enum_body(self, p):
+        '''enum_body : enum_body_part
+                    | enum_body enum_body_part'''
+        if len(p) == 2:
+            p[0] = [p[1]]
+        else:
+            p[0] = p[1] + [p[2]]
+
+    def p_enum_body_opt(self, p):
+        '''enum_body_opt : empty'''
+        p[0] = []
+
+    def p_enum_body_opt2(self, p):
+        '''enum_body_opt : enum_body'''
+        p[0] = p[1]
+
+    # Root of the enum declaration.
+    # enum_definition ::= 'enum' ident '{' { ident '=' integer ';' }* '}'
+    def p_enum_definition(self, p):
+        '''enum_definition : ENUM NAME LBRACE enum_body_opt RBRACE'''
+        p[0] = EnumDeclaration(Name(p[2]), p[4])
+
+    def p_extensions_to(self, p):
+        '''extensions_to : MAX'''
+        p[0] = ExtensionsMax()
+
+    def p_extensions_to2(self, p):
+        '''extensions_to : NUM'''
+        p[0] = p[1]
+
+    # extensions_definition ::= 'extensions' integer 'to' integer ';'
+    def p_extensions_definition(self, p):
+        '''extensions_definition : EXTENSIONS NUM TO extensions_to SEMI'''
+        p[0] = ExtensionsDirective(p[2], p[4])
+
+    # message_extension ::= 'extend' ident '{' message_body '}'
+    def p_message_extension(self, p):
+        '''message_extension : EXTEND NAME LBRACE message_body RBRACE'''
+        p[0] = MessageExtension(Name(p[2]), p[4])
+
+    def p_message_body_part(self, p):
+        '''message_body_part : field_definition
+                           | enum_definition
+                           | message_definition
+                           | extensions_definition
+                           | message_extension'''
+        p[0] = p[1]
+
+    # message_body ::= { field_definition | enum_definition | message_definition | extensions_definition | message_extension }*
+    def p_message_body(self, p):
+        '''message_body : empty'''
+        p[0] = []
+
+    # message_body ::= { field_definition | enum_definition | message_definition | extensions_definition | message_extension }*
+    def p_message_body2(self, p):
+        '''message_body : message_body_part
+                      | message_body message_body_part'''
+        if len(p) == 2:
+            p[0] = [p[1]]
+        else:
+            p[0] = p[1] + [p[2]]
+
+    # Root of the message declaration.
+    # message_definition = MESSAGE_ - ident("messageId") + LBRACE + message_body("body") + RBRACE
+    def p_message_definition(self, p):
+        '''message_definition : MESSAGE NAME LBRACE message_body RBRACE'''
+        p[0] = MessageDeclaration(Name(p[2]), p[4])
+
+    # method_definition ::= 'rpc' ident '(' [ ident ] ')' 'returns' '(' [ ident ] ')' ';'
+    def p_method_definition(self, p):
+        '''method_definition : RPC NAME LPAR NAME RPAR RETURNS LPAR NAME RPAR'''
+        p[0] = MethodDefinition(Name(p[2]), Name(p[4]), Name(p[8]))
+
+    def p_method_definition_opt(self, p):
+        '''method_definition_opt : empty'''
+        p[0] = []
+
+    def p_method_definition_opt2(self, p):
+        '''method_definition_opt : method_definition
+                          | method_definition_opt method_definition'''
+        if len(p) == 2:
+            p[0] = [p[1]]
+        else:
+            p[0] = p[1] + [p[2]]
+
+    # service_definition ::= 'service' ident '{' method_definition* '}'
+    # service_definition = SERVICE_ - ident("serviceName") + LBRACE + ZeroOrMore(Group(method_definition)) + RBRACE
+    def p_service_definition(self, p):
+        '''service_definition : SERVICE NAME LBRACE method_definition_opt RBRACE'''
+        p[0] = ServiceDeclaration(Name(p[2]), p[4])
+
+    # package_directive ::= 'package' ident [ '.' ident]* ';'
+    def p_package_directive(self,p):
+        '''package_directive : PACKAGE NAME SEMI'''
+        p[0] = PackageDeclaration(Name(p[2]))
+
+    # import_directive = IMPORT_ - quotedString("importFileSpec") + SEMI
+    def p_import_directive(self, p):
+        '''import_directive : IMPORT STRING_LITERAL SEMI'''
+        p[0] = ImportStatement(Literal(p[2]))
+
+    def p_option_rvalue(self, p):
+        '''option_rvalue : NUM
+                         | TRUE
+                         | FALSE'''
+        p[0] = p[1]
+
+    def p_option_rvalue2(self, p):
+        '''option_rvalue : STRING_LITERAL'''
+        p[0] = Literal(p[1])
+
+    # option_directive = OPTION_ - ident("optionName") + EQ + quotedString("optionValue") + SEMI
+    def p_option_directive(self, p):
+        '''option_directive : OPTION NAME EQ option_rvalue SEMI'''
+        p[0] = OptionDefinition(Name(p[2]), p[4])
+
+    # topLevelStatement = Group(message_definition | message_extension | enum_definition | service_definition | import_directive | option_directive)
+    def p_topLevel(self,p):
+        '''topLevel : message_definition
+                    | message_extension
+                    | enum_definition
+                    | service_definition
+                    | import_directive
+                    | option_directive'''
+        p[0] = p[1]
+
+    def p_package_definition(self, p):
+        '''package_definition : package_directive'''
+        p[0] = p[1]
+
+    def p_packages2(self, p):
+        '''package_definition : empty'''
+        p[0] = []
+
+    def p_statements2(self, p):
+        '''statements : topLevel
+                      | statements topLevel'''
+        if len(p) == 2:
+            p[0] = [p[1]]
+        else:
+            p[0] = p[1] + [p[2]]
+
+    def p_statements(self, p):
+        '''statements : empty'''
+        p[0] = []
+
+    # parser = Optional(package_directive) + ZeroOrMore(topLevelStatement)
+    def p_goal2(self, p):
+        '''goal : package_definition statements'''
+        p[0] = [p[1], p[2]]
+
+    def p_error(self, p):
+        print('error: {}'.format(p))
+
+class ProtobufAnalyzer(object):
+
+    def __init__(self):
+        self.lexer = lex.lex(module=ProtobufLexer(), optimize=1)
+        self.parser = yacc.yacc(module=ProtobufParser(), start='goal', optimize=1)
+
+    def tokenize_string(self, code):
+        self.lexer.input(code)
+        for token in self.lexer:
+            print(token)
+
+    def tokenize_file(self, _file):
+        if type(_file) == str:
+            _file = file(_file)
+        content = ''
+        for line in _file:
+            content += line
+        return self.tokenize_string(content)
+
+    def parse_string(self, code, debug=0, lineno=1, prefix=''):
+        self.lexer.lineno = lineno
+        return self.parser.parse(prefix + code, lexer=self.lexer, debug=debug)
+
+    def parse_file(self, _file, debug=0):
+        if type(_file) == str:
+            _file = file(_file)
+        content = ''
+        for line in _file:
+            content += line
+        return self.parse_string(content, debug=debug)