Multiline strings

src/example.toml

@@ -1,5 +1,6 @@
 title = "TOML Example"
 [owner]
-name = "Tom Preston-Werner"
+name = """Tom Preston-Werner
+test"""
 date = 2010-04-23
 time = 21:30:00

src/lexer.py

@@ -1,8 +1,9 @@
-import ply.lex as lex
+from ply import lex
 
 tokens = [
     "ID",
     "STR",
+    "MLSTR",
     "DATE",
     "TIME",
     "DATETIME",
@@ -17,6 +18,10 @@ tokens = [
 ]
 
 
+def t_MLSTR(t):
+    r"\"\"\"[^\"]+\"\"\""
+    return t
+
 # STR needs to be the first one to catch
 def t_STR(t):
     r"\"[^\"]+\""

src/parser.py

@@ -1,4 +1,4 @@
-import ply.yacc as yacc
+from ply import yacc
 from lexer import tokens
 
 
@@ -89,6 +89,9 @@ def p_key_int(p):
 def p_value_str(p):
     "value : STR"
 
+def p_value_mlstr(p):
+    "value : MLSTR"
+
 def p_value_date(p):
     "value : DATE"
 

src/ply/__init__.py

@@ -0,0 +1,5 @@
+# PLY package
+# Author: David Beazley (dave@dabeaz.com)
+# https://github.com/dabeaz/ply
+
+__version__ = '2022.10.27'

src/ply/lex.py

@@ -0,0 +1,901 @@
+# -----------------------------------------------------------------------------
+# ply: lex.py
+#
+# Copyright (C) 2001-2022
+# David M. Beazley (Dabeaz LLC)
+# All rights reserved.
+#
+# Latest version: https://github.com/dabeaz/ply
+#
+# 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 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.
+# -----------------------------------------------------------------------------
+
+import re
+import sys
+import types
+import copy
+import os
+import inspect
+
+# This tuple contains acceptable string types
+StringTypes = (str, bytes)
+
+# This regular expression is used to match valid token names
+_is_identifier = re.compile(r'^[a-zA-Z0-9_]+$')
+
+# Exception thrown when invalid token encountered and no default error
+# handler is defined.
+class LexError(Exception):
+    def __init__(self, message, s):
+        self.args = (message,)
+        self.text = s
+
+# Token class.  This class is used to represent the tokens produced.
+class LexToken(object):
+    def __repr__(self):
+        return f'LexToken({self.type},{self.value!r},{self.lineno},{self.lexpos})'
+
+# 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
+
+# -----------------------------------------------------------------------------
+#                        === Lexing Engine ===
+#
+# The following Lexer class implements the lexer runtime.   There are only
+# a few public methods and attributes:
+#
+#    input()          -  Store a new string in the lexer
+#    token()          -  Get the next token
+#    clone()          -  Clone the lexer
+#
+#    lineno           -  Current line number
+#    lexpos           -  Current position in the input string
+# -----------------------------------------------------------------------------
+
+class Lexer:
+    def __init__(self):
+        self.lexre = None             # Master regular expression. This is a list of
+                                      # tuples (re, findex) where re is a compiled
+                                      # regular expression and findex is a list
+                                      # mapping regex group numbers to rules
+        self.lexretext = None         # Current regular expression strings
+        self.lexstatere = {}          # Dictionary mapping lexer states to master regexs
+        self.lexstateretext = {}      # Dictionary mapping lexer states to regex strings
+        self.lexstaterenames = {}     # Dictionary mapping lexer states to symbol names
+        self.lexstate = 'INITIAL'     # Current lexer state
+        self.lexstatestack = []       # Stack of lexer states
+        self.lexstateinfo = None      # State information
+        self.lexstateignore = {}      # Dictionary of ignored characters for each state
+        self.lexstateerrorf = {}      # Dictionary of error functions for each state
+        self.lexstateeoff = {}        # Dictionary of eof functions for each state
+        self.lexreflags = 0           # Optional re compile flags
+        self.lexdata = None           # Actual input data (as a string)
+        self.lexpos = 0               # Current position in input text
+        self.lexlen = 0               # Length of the input text
+        self.lexerrorf = None         # Error rule (if any)
+        self.lexeoff = None           # EOF rule (if any)
+        self.lextokens = None         # List of valid tokens
+        self.lexignore = ''           # Ignored characters
+        self.lexliterals = ''         # Literal characters that can be passed through
+        self.lexmodule = None         # Module
+        self.lineno = 1               # Current line number
+
+    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
+
+    # ------------------------------------------------------------
+    # input() - Push a new string into the lexer
+    # ------------------------------------------------------------
+    def input(self, s):
+        self.lexdata = s
+        self.lexpos = 0
+        self.lexlen = len(s)
+
+    # ------------------------------------------------------------
+    # begin() - Changes the lexing state
+    # ------------------------------------------------------------
+    def begin(self, state):
+        if state not in self.lexstatere:
+            raise ValueError(f'Undefined state {state!r}')
+        self.lexre = self.lexstatere[state]
+        self.lexretext = self.lexstateretext[state]
+        self.lexignore = self.lexstateignore.get(state, '')
+        self.lexerrorf = self.lexstateerrorf.get(state, None)
+        self.lexeoff = self.lexstateeoff.get(state, None)
+        self.lexstate = state
+
+    # ------------------------------------------------------------
+    # push_state() - Changes the lexing state and saves old on stack
+    # ------------------------------------------------------------
+    def push_state(self, state):
+        self.lexstatestack.append(self.lexstate)
+        self.begin(state)
+
+    # ------------------------------------------------------------
+    # pop_state() - Restores the previous state
+    # ------------------------------------------------------------
+    def pop_state(self):
+        self.begin(self.lexstatestack.pop())
+
+    # ------------------------------------------------------------
+    # current_state() - Returns the current lexing state
+    # ------------------------------------------------------------
+    def current_state(self):
+        return self.lexstate
+
+    # ------------------------------------------------------------
+    # skip() - Skip ahead n characters
+    # ------------------------------------------------------------
+    def skip(self, n):
+        self.lexpos += n
+
+    # ------------------------------------------------------------
+    # token() - 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)
+                del tok.lexer
+                del self.lexmatch
+
+                # 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
+                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(f"Scanning error. Illegal character {lexdata[lexpos]!r}",
+                                       lexdata[lexpos:])
+                    lexpos = self.lexpos
+                    if not newtok:
+                        continue
+                    return newtok
+
+                self.lexpos = lexpos
+                raise LexError(f"Illegal character {lexdata[lexpos]!r} at index {lexpos}",
+                               lexdata[lexpos:])
+
+        if self.lexeoff:
+            tok = LexToken()
+            tok.type = 'eof'
+            tok.value = ''
+            tok.lineno = self.lineno
+            tok.lexpos = lexpos
+            tok.lexer = self
+            self.lexpos = lexpos
+            newtok = self.lexeoff(tok)
+            return newtok
+
+        self.lexpos = lexpos + 1
+        if self.lexdata is None:
+            raise RuntimeError('No input string given with input()')
+        return None
+
+    # Iterator interface
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        t = self.token()
+        if t is None:
+            raise StopIteration
+        return t
+
+# -----------------------------------------------------------------------------
+#                           ==== Lex Builder ===
+#
+# The functions and classes below are used to collect lexing information
+# and build a Lexer object from it.
+# -----------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
+# _get_regex(func)
+#
+# Returns the regular expression assigned to a function either as a doc string
+# or as a .regex attribute attached by the @TOKEN decorator.
+# -----------------------------------------------------------------------------
+def _get_regex(func):
+    return getattr(func, 'regex', func.__doc__)
+
+# -----------------------------------------------------------------------------
+# get_caller_module_dict()
+#
+# This function returns a dictionary containing all of the symbols defined within
+# a caller further down the call stack.  This is used to get the environment
+# associated with the yacc() call if none was provided.
+# -----------------------------------------------------------------------------
+def get_caller_module_dict(levels):
+    f = sys._getframe(levels)
+    return { **f.f_globals, **f.f_locals }
+
+# -----------------------------------------------------------------------------
+# _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, 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 = (len(relist) // 2) + 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):
+    parts = s.split('_')
+    for i, part in enumerate(parts[1:], 1):
+        if part not in names and part != 'ANY':
+            break
+
+    if i > 1:
+        states = tuple(parts[1:i])
+    else:
+        states = ('INITIAL',)
+
+    if 'ANY' in states:
+        states = tuple(names)
+
+    tokenname = '_'.join(parts[i:])
+    return (states, tokenname)
+
+
+# -----------------------------------------------------------------------------
+# LexerReflect()
+#
+# This class represents information needed to build a lexer as extracted from a
+# user's input file.
+# -----------------------------------------------------------------------------
+class LexerReflect(object):
+    def __init__(self, ldict, log=None, reflags=0):
+        self.ldict      = ldict
+        self.error_func = None
+        self.tokens     = []
+        self.reflags    = reflags
+        self.stateinfo  = {'INITIAL': 'inclusive'}
+        self.modules    = set()
+        self.error      = False
+        self.log        = PlyLogger(sys.stderr) if log is None else log
+
+    # Get all of the basic information
+    def get_all(self):
+        self.get_tokens()
+        self.get_literals()
+        self.get_states()
+        self.get_rules()
+
+    # Validate all of the information
+    def validate_all(self):
+        self.validate_tokens()
+        self.validate_literals()
+        self.validate_rules()
+        return self.error
+
+    # Get the tokens map
+    def get_tokens(self):
+        tokens = self.ldict.get('tokens', None)
+        if not tokens:
+            self.log.error('No token list is defined')
+            self.error = True
+            return
+
+        if not isinstance(tokens, (list, tuple)):
+            self.log.error('tokens must be a list or tuple')
+            self.error = True
+            return
+
+        if not tokens:
+            self.log.error('tokens is empty')
+            self.error = True
+            return
+
+        self.tokens = tokens
+
+    # Validate the tokens
+    def validate_tokens(self):
+        terminals = {}
+        for n in self.tokens:
+            if not _is_identifier.match(n):
+                self.log.error(f"Bad token name {n!r}")
+                self.error = True
+            if n in terminals:
+                self.log.warning(f"Token {n!r} multiply defined")
+            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(f'Invalid literal {c!r}. Must be a single character')
+                    self.error = True
+
+        except TypeError:
+            self.log.error('Invalid literals specification. literals must be a sequence of characters')
+            self.error = True
+
+    def get_states(self):
+        self.states = self.ldict.get('states', None)
+        # Build statemap
+        if self.states:
+            if not isinstance(self.states, (tuple, list)):
+                self.log.error('states must be defined as a tuple or list')
+                self.error = True
+            else:
+                for s in self.states:
+                    if not isinstance(s, tuple) or len(s) != 2:
+                        self.log.error("Invalid state specifier %r. Must be a tuple (statename,'exclusive|inclusive')", s)
+                        self.error = True
+                        continue
+                    name, statetype = s
+                    if not isinstance(name, StringTypes):
+                        self.log.error('State name %r must be a string', name)
+                        self.error = True
+                        continue
+                    if not (statetype == 'inclusive' or statetype == 'exclusive'):
+                        self.log.error("State type for state %r must be 'inclusive' or 'exclusive'", name)
+                        self.error = True
+                        continue
+                    if name in self.stateinfo:
+                        self.log.error("State %r already defined", name)
+                        self.error = True
+                        continue
+                    self.stateinfo[name] = statetype
+
+    # Get all of the symbols with a t_ prefix and sort them into various
+    # categories (functions, strings, error functions, and ignore characters)
+
+    def get_rules(self):
+        tsymbols = [f for f in self.ldict if f[:2] == 't_']
+
+        # Now build up a list of functions and a list of strings
+        self.toknames = {}        # Mapping of symbols to token names
+        self.funcsym  = {}        # Symbols defined as functions
+        self.strsym   = {}        # Symbols defined as strings
+        self.ignore   = {}        # Ignore strings by state
+        self.errorf   = {}        # Error functions by state
+        self.eoff     = {}        # EOF functions by state
+
+        for s in self.stateinfo:
+            self.funcsym[s] = []
+            self.strsym[s] = []
+
+        if len(tsymbols) == 0:
+            self.log.error('No rules of the form t_rulename are defined')
+            self.error = True
+            return
+
+        for f in tsymbols:
+            t = self.ldict[f]
+            states, tokname = _statetoken(f, self.stateinfo)
+            self.toknames[f] = tokname
+
+            if hasattr(t, '__call__'):
+                if tokname == 'error':
+                    for s in states:
+                        self.errorf[s] = t
+                elif tokname == 'eof':
+                    for s in states:
+                        self.eoff[s] = t
+                elif tokname == 'ignore':
+                    line = t.__code__.co_firstlineno
+                    file = t.__code__.co_filename
+                    self.log.error("%s:%d: Rule %r must be defined as a string", file, line, t.__name__)
+                    self.error = True
+                else:
+                    for s in states:
+                        self.funcsym[s].append((f, t))
+            elif isinstance(t, StringTypes):
+                if tokname == 'ignore':
+                    for s in states:
+                        self.ignore[s] = t
+                    if '\\' in t:
+                        self.log.warning("%s contains a literal backslash '\\'", f)
+
+                elif tokname == 'error':
+                    self.log.error("Rule %r must be defined as a function", f)
+                    self.error = True
+                else:
+                    for s in states:
+                        self.strsym[s].append((f, t))
+            else:
+                self.log.error('%s not defined as a function or string', f)
+                self.error = True
+
+        # Sort the functions by line number
+        for f in self.funcsym.values():
+            f.sort(key=lambda x: x[1].__code__.co_firstlineno)
+
+        # Sort the strings by regular expression length
+        for s in self.strsym.values():
+            s.sort(key=lambda x: len(x[1]), reverse=True)
+
+    # Validate all of the t_rules collected
+    def validate_rules(self):
+        for state in self.stateinfo:
+            # Validate all rules defined by functions
+
+            for fname, f in self.funcsym[state]:
+                line = f.__code__.co_firstlineno
+                file = f.__code__.co_filename
+                module = inspect.getmodule(f)
+                self.modules.add(module)
+
+                tokname = self.toknames[fname]
+                if isinstance(f, types.MethodType):
+                    reqargs = 2
+                else:
+                    reqargs = 1
+                nargs = f.__code__.co_argcount
+                if nargs > reqargs:
+                    self.log.error("%s:%d: Rule %r has too many arguments", file, line, f.__name__)
+                    self.error = True
+                    continue
+
+                if nargs < reqargs:
+                    self.log.error("%s:%d: Rule %r requires an argument", file, line, f.__name__)
+                    self.error = True
+                    continue
+
+                if not _get_regex(f):
+                    self.log.error("%s:%d: No regular expression defined for rule %r", file, line, f.__name__)
+                    self.error = True
+                    continue
+
+                try:
+                    c = re.compile('(?P<%s>%s)' % (fname, _get_regex(f)), self.reflags)
+                    if c.match(''):
+                        self.log.error("%s:%d: Regular expression for rule %r matches empty string", file, line, f.__name__)
+                        self.error = True
+                except re.error as e:
+                    self.log.error("%s:%d: Invalid regular expression for rule '%s'. %s", file, line, f.__name__, e)
+                    if '#' in _get_regex(f):
+                        self.log.error("%s:%d. Make sure '#' in rule %r is escaped with '\\#'", file, line, f.__name__)
+                    self.error = True
+
+            # Validate all rules defined by strings
+            for name, r in self.strsym[state]:
+                tokname = self.toknames[name]
+                if tokname == 'error':
+                    self.log.error("Rule %r must be defined as a function", name)
+                    self.error = True
+                    continue
+
+                if tokname not in self.tokens and tokname.find('ignore_') < 0:
+                    self.log.error("Rule %r defined for an unspecified token %s", name, tokname)
+                    self.error = True
+                    continue
+
+                try:
+                    c = re.compile('(?P<%s>%s)' % (name, r), self.reflags)
+                    if (c.match('')):
+                        self.log.error("Regular expression for rule %r matches empty string", name)
+                        self.error = True
+                except re.error as e:
+                    self.log.error("Invalid regular expression for rule %r. %s", name, e)
+                    if '#' in r:
+                        self.log.error("Make sure '#' in rule %r is escaped with '\\#'", name)
+                    self.error = True
+
+            if not self.funcsym[state] and not self.strsym[state]:
+                self.log.error("No rules defined for state %r", state)
+                self.error = True
+
+            # Validate the error function
+            efunc = self.errorf.get(state, None)
+            if efunc:
+                f = efunc
+                line = f.__code__.co_firstlineno
+                file = f.__code__.co_filename
+                module = inspect.getmodule(f)
+                self.modules.add(module)
+
+                if isinstance(f, types.MethodType):
+                    reqargs = 2
+                else:
+                    reqargs = 1
+                nargs = f.__code__.co_argcount
+                if nargs > reqargs:
+                    self.log.error("%s:%d: Rule %r has too many arguments", file, line, f.__name__)
+                    self.error = True
+
+                if nargs < reqargs:
+                    self.log.error("%s:%d: Rule %r requires an argument", file, line, f.__name__)
+                    self.error = True
+
+        for module in self.modules:
+            self.validate_module(module)
+
+    # -----------------------------------------------------------------------------
+    # validate_module()
+    #
+    # This checks to see if there are duplicated t_rulename() functions or strings
+    # in the parser input file.  This is done using a simple regular expression
+    # match on each line in the source code of the given module.
+    # -----------------------------------------------------------------------------
+
+    def validate_module(self, module):
+        try:
+            lines, linen = inspect.getsourcelines(module)
+        except IOError:
+            return
+
+        fre = re.compile(r'\s*def\s+(t_[a-zA-Z_0-9]*)\(')
+        sre = re.compile(r'\s*(t_[a-zA-Z_0-9]*)\s*=')
+
+        counthash = {}
+        linen += 1
+        for line in lines:
+            m = fre.match(line)
+            if not m:
+                m = sre.match(line)
+            if m:
+                name = m.group(1)
+                prev = counthash.get(name)
+                if not prev:
+                    counthash[name] = linen
+                else:
+                    filename = inspect.getsourcefile(module)
+                    self.log.error('%s:%d: Rule %s redefined. Previously defined on line %d', filename, linen, name, prev)
+                    self.error = True
+            linen += 1
+
+# -----------------------------------------------------------------------------
+# lex(module)
+#
+# Build all of the regular expression rules from definitions in the supplied module
+# -----------------------------------------------------------------------------
+def lex(*, module=None, object=None, debug=False, 
+        reflags=int(re.VERBOSE), debuglog=None, errorlog=None):
+
+    global lexer
+
+    ldict = None
+    stateinfo  = {'INITIAL': 'inclusive'}
+    lexobj = Lexer()
+    global token, input
+
+    if errorlog is None:
+        errorlog = PlyLogger(sys.stderr)
+
+    if debug:
+        if debuglog is None:
+            debuglog = PlyLogger(sys.stderr)
+
+    # Get the module dictionary used for the lexer
+    if object:
+        module = object
+
+    # Get the module dictionary used for the parser
+    if module:
+        _items = [(k, getattr(module, k)) for k in dir(module)]
+        ldict = dict(_items)
+        # If no __file__ attribute is available, try to obtain it from the __module__ instead
+        if '__file__' not in ldict:
+            ldict['__file__'] = sys.modules[ldict['__module__']].__file__
+    else:
+        ldict = get_caller_module_dict(2)
+
+    # Collect parser information from the dictionary
+    linfo = LexerReflect(ldict, log=errorlog, reflags=reflags)
+    linfo.get_all()
+    if linfo.validate_all():
+        raise SyntaxError("Can't build lexer")
+
+    # Dump some basic debugging information
+    if debug:
+        debuglog.info('lex: tokens   = %r', linfo.tokens)
+        debuglog.info('lex: literals = %r', linfo.literals)
+        debuglog.info('lex: states   = %r', linfo.stateinfo)
+
+    # Build a dictionary of valid token names
+    lexobj.lextokens = set()
+    for n in linfo.tokens:
+        lexobj.lextokens.add(n)
+
+    # Get literals specification
+    if isinstance(linfo.literals, (list, tuple)):
+        lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals)
+    else:
+        lexobj.lexliterals = linfo.literals
+
+    lexobj.lextokens_all = lexobj.lextokens | set(lexobj.lexliterals)
+
+    # Get the stateinfo dictionary
+    stateinfo = linfo.stateinfo
+
+    regexs = {}
+    # Build the master regular expressions
+    for state in stateinfo:
+        regex_list = []
+
+        # Add rules defined by functions first
+        for fname, f in linfo.funcsym[state]:
+            regex_list.append('(?P<%s>%s)' % (fname, _get_regex(f)))
+            if debug:
+                debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", fname, _get_regex(f), state)
+
+        # Now add all of the simple rules
+        for name, r in linfo.strsym[state]:
+            regex_list.append('(?P<%s>%s)' % (name, r))
+            if debug:
+                debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", name, r, state)
+
+        regexs[state] = regex_list
+
+    # Build the master regular expressions
+
+    if debug:
+        debuglog.info('lex: ==== MASTER REGEXS FOLLOW ====')
+
+    for state in regexs:
+        lexre, re_text, re_names = _form_master_re(regexs[state], reflags, ldict, linfo.toknames)
+        lexobj.lexstatere[state] = lexre
+        lexobj.lexstateretext[state] = re_text
+        lexobj.lexstaterenames[state] = re_names
+        if debug:
+            for i, text in enumerate(re_text):
+                debuglog.info("lex: state '%s' : regex[%d] = '%s'", state, i, text)
+
+    # For inclusive states, we need to add the regular expressions from the INITIAL state
+    for state, stype in stateinfo.items():
+        if state != 'INITIAL' and stype == 'inclusive':
+            lexobj.lexstatere[state].extend(lexobj.lexstatere['INITIAL'])
+            lexobj.lexstateretext[state].extend(lexobj.lexstateretext['INITIAL'])
+            lexobj.lexstaterenames[state].extend(lexobj.lexstaterenames['INITIAL'])
+
+    lexobj.lexstateinfo = stateinfo
+    lexobj.lexre = lexobj.lexstatere['INITIAL']
+    lexobj.lexretext = lexobj.lexstateretext['INITIAL']
+    lexobj.lexreflags = reflags
+
+    # Set up ignore variables
+    lexobj.lexstateignore = linfo.ignore
+    lexobj.lexignore = lexobj.lexstateignore.get('INITIAL', '')
+
+    # Set up error functions
+    lexobj.lexstateerrorf = linfo.errorf
+    lexobj.lexerrorf = linfo.errorf.get('INITIAL', None)
+    if not lexobj.lexerrorf:
+        errorlog.warning('No t_error rule is defined')
+
+    # Set up eof functions
+    lexobj.lexstateeoff = linfo.eoff
+    lexobj.lexeoff = linfo.eoff.get('INITIAL', None)
+
+    # Check state information for ignore and error rules
+    for s, stype in stateinfo.items():
+        if stype == 'exclusive':
+            if s not in linfo.errorf:
+                errorlog.warning("No error rule is defined for exclusive state %r", s)
+            if s not in linfo.ignore and lexobj.lexignore:
+                errorlog.warning("No ignore rule is defined for exclusive state %r", s)
+        elif stype == 'inclusive':
+            if s not in linfo.errorf:
+                linfo.errorf[s] = linfo.errorf.get('INITIAL', None)
+            if s not in linfo.ignore:
+                linfo.ignore[s] = linfo.ignore.get('INITIAL', '')
+
+    # Create global versions of the token() and input() functions
+    token = lexobj.token
+    input = lexobj.input
+    lexer = lexobj
+
+    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]
+            with open(filename) as f:
+                data = f.read()
+        except IndexError:
+            sys.stdout.write('Reading from standard input (type EOF to end):\n')
+            data = sys.stdin.read()
+
+    if lexer:
+        _input = lexer.input
+    else:
+        _input = input
+    _input(data)
+    if lexer:
+        _token = lexer.token
+    else:
+        _token = token
+
+    while True:
+        tok = _token()
+        if not tok:
+            break
+        sys.stdout.write(f'({tok.type},{tok.value!r},{tok.lineno},{tok.lexpos})\n')
+
+# -----------------------------------------------------------------------------
+# @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