diff lib/python3.8/site-packages/setuptools/_vendor/pyparsing.py @ 0:9e54283cc701 draft

"planemo upload commit d12c32a45bcd441307e632fca6d9af7d60289d44"
author guerler
date Mon, 27 Jul 2020 03:47:31 -0400
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+++ b/lib/python3.8/site-packages/setuptools/_vendor/pyparsing.py	Mon Jul 27 03:47:31 2020 -0400
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+# module pyparsing.py
+#
+# Copyright (c) 2003-2018  Paul T. McGuire
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__doc__ = \
+"""
+pyparsing module - Classes and methods to define and execute parsing grammars
+=============================================================================
+
+The pyparsing module is an alternative approach to creating and executing simple grammars,
+vs. the traditional lex/yacc approach, or the use of regular expressions.  With pyparsing, you
+don't need to learn a new syntax for defining grammars or matching expressions - the parsing module
+provides a library of classes that you use to construct the grammar directly in Python.
+
+Here is a program to parse "Hello, World!" (or any greeting of the form 
+C{"<salutation>, <addressee>!"}), built up using L{Word}, L{Literal}, and L{And} elements 
+(L{'+'<ParserElement.__add__>} operator gives L{And} expressions, strings are auto-converted to
+L{Literal} expressions)::
+
+    from pyparsing import Word, alphas
+
+    # define grammar of a greeting
+    greet = Word(alphas) + "," + Word(alphas) + "!"
+
+    hello = "Hello, World!"
+    print (hello, "->", greet.parseString(hello))
+
+The program outputs the following::
+
+    Hello, World! -> ['Hello', ',', 'World', '!']
+
+The Python representation of the grammar is quite readable, owing to the self-explanatory
+class names, and the use of '+', '|' and '^' operators.
+
+The L{ParseResults} object returned from L{ParserElement.parseString<ParserElement.parseString>} can be accessed as a nested list, a dictionary, or an
+object with named attributes.
+
+The pyparsing module handles some of the problems that are typically vexing when writing text parsers:
+ - extra or missing whitespace (the above program will also handle "Hello,World!", "Hello  ,  World  !", etc.)
+ - quoted strings
+ - embedded comments
+
+
+Getting Started -
+-----------------
+Visit the classes L{ParserElement} and L{ParseResults} to see the base classes that most other pyparsing
+classes inherit from. Use the docstrings for examples of how to:
+ - construct literal match expressions from L{Literal} and L{CaselessLiteral} classes
+ - construct character word-group expressions using the L{Word} class
+ - see how to create repetitive expressions using L{ZeroOrMore} and L{OneOrMore} classes
+ - use L{'+'<And>}, L{'|'<MatchFirst>}, L{'^'<Or>}, and L{'&'<Each>} operators to combine simple expressions into more complex ones
+ - associate names with your parsed results using L{ParserElement.setResultsName}
+ - find some helpful expression short-cuts like L{delimitedList} and L{oneOf}
+ - find more useful common expressions in the L{pyparsing_common} namespace class
+"""
+
+__version__ = "2.2.1"
+__versionTime__ = "18 Sep 2018 00:49 UTC"
+__author__ = "Paul McGuire <ptmcg@users.sourceforge.net>"
+
+import string
+from weakref import ref as wkref
+import copy
+import sys
+import warnings
+import re
+import sre_constants
+import collections
+import pprint
+import traceback
+import types
+from datetime import datetime
+
+try:
+    from _thread import RLock
+except ImportError:
+    from threading import RLock
+
+try:
+    # Python 3
+    from collections.abc import Iterable
+    from collections.abc import MutableMapping
+except ImportError:
+    # Python 2.7
+    from collections import Iterable
+    from collections import MutableMapping
+
+try:
+    from collections import OrderedDict as _OrderedDict
+except ImportError:
+    try:
+        from ordereddict import OrderedDict as _OrderedDict
+    except ImportError:
+        _OrderedDict = None
+
+#~ sys.stderr.write( "testing pyparsing module, version %s, %s\n" % (__version__,__versionTime__ ) )
+
+__all__ = [
+'And', 'CaselessKeyword', 'CaselessLiteral', 'CharsNotIn', 'Combine', 'Dict', 'Each', 'Empty',
+'FollowedBy', 'Forward', 'GoToColumn', 'Group', 'Keyword', 'LineEnd', 'LineStart', 'Literal',
+'MatchFirst', 'NoMatch', 'NotAny', 'OneOrMore', 'OnlyOnce', 'Optional', 'Or',
+'ParseBaseException', 'ParseElementEnhance', 'ParseException', 'ParseExpression', 'ParseFatalException',
+'ParseResults', 'ParseSyntaxException', 'ParserElement', 'QuotedString', 'RecursiveGrammarException',
+'Regex', 'SkipTo', 'StringEnd', 'StringStart', 'Suppress', 'Token', 'TokenConverter', 
+'White', 'Word', 'WordEnd', 'WordStart', 'ZeroOrMore',
+'alphanums', 'alphas', 'alphas8bit', 'anyCloseTag', 'anyOpenTag', 'cStyleComment', 'col',
+'commaSeparatedList', 'commonHTMLEntity', 'countedArray', 'cppStyleComment', 'dblQuotedString',
+'dblSlashComment', 'delimitedList', 'dictOf', 'downcaseTokens', 'empty', 'hexnums',
+'htmlComment', 'javaStyleComment', 'line', 'lineEnd', 'lineStart', 'lineno',
+'makeHTMLTags', 'makeXMLTags', 'matchOnlyAtCol', 'matchPreviousExpr', 'matchPreviousLiteral',
+'nestedExpr', 'nullDebugAction', 'nums', 'oneOf', 'opAssoc', 'operatorPrecedence', 'printables',
+'punc8bit', 'pythonStyleComment', 'quotedString', 'removeQuotes', 'replaceHTMLEntity', 
+'replaceWith', 'restOfLine', 'sglQuotedString', 'srange', 'stringEnd',
+'stringStart', 'traceParseAction', 'unicodeString', 'upcaseTokens', 'withAttribute',
+'indentedBlock', 'originalTextFor', 'ungroup', 'infixNotation','locatedExpr', 'withClass',
+'CloseMatch', 'tokenMap', 'pyparsing_common',
+]
+
+system_version = tuple(sys.version_info)[:3]
+PY_3 = system_version[0] == 3
+if PY_3:
+    _MAX_INT = sys.maxsize
+    basestring = str
+    unichr = chr
+    _ustr = str
+
+    # build list of single arg builtins, that can be used as parse actions
+    singleArgBuiltins = [sum, len, sorted, reversed, list, tuple, set, any, all, min, max]
+
+else:
+    _MAX_INT = sys.maxint
+    range = xrange
+
+    def _ustr(obj):
+        """Drop-in replacement for str(obj) that tries to be Unicode friendly. It first tries
+           str(obj). If that fails with a UnicodeEncodeError, then it tries unicode(obj). It
+           then < returns the unicode object | encodes it with the default encoding | ... >.
+        """
+        if isinstance(obj,unicode):
+            return obj
+
+        try:
+            # If this works, then _ustr(obj) has the same behaviour as str(obj), so
+            # it won't break any existing code.
+            return str(obj)
+
+        except UnicodeEncodeError:
+            # Else encode it
+            ret = unicode(obj).encode(sys.getdefaultencoding(), 'xmlcharrefreplace')
+            xmlcharref = Regex(r'&#\d+;')
+            xmlcharref.setParseAction(lambda t: '\\u' + hex(int(t[0][2:-1]))[2:])
+            return xmlcharref.transformString(ret)
+
+    # build list of single arg builtins, tolerant of Python version, that can be used as parse actions
+    singleArgBuiltins = []
+    import __builtin__
+    for fname in "sum len sorted reversed list tuple set any all min max".split():
+        try:
+            singleArgBuiltins.append(getattr(__builtin__,fname))
+        except AttributeError:
+            continue
+            
+_generatorType = type((y for y in range(1)))
+ 
+def _xml_escape(data):
+    """Escape &, <, >, ", ', etc. in a string of data."""
+
+    # ampersand must be replaced first
+    from_symbols = '&><"\''
+    to_symbols = ('&'+s+';' for s in "amp gt lt quot apos".split())
+    for from_,to_ in zip(from_symbols, to_symbols):
+        data = data.replace(from_, to_)
+    return data
+
+class _Constants(object):
+    pass
+
+alphas     = string.ascii_uppercase + string.ascii_lowercase
+nums       = "0123456789"
+hexnums    = nums + "ABCDEFabcdef"
+alphanums  = alphas + nums
+_bslash    = chr(92)
+printables = "".join(c for c in string.printable if c not in string.whitespace)
+
+class ParseBaseException(Exception):
+    """base exception class for all parsing runtime exceptions"""
+    # Performance tuning: we construct a *lot* of these, so keep this
+    # constructor as small and fast as possible
+    def __init__( self, pstr, loc=0, msg=None, elem=None ):
+        self.loc = loc
+        if msg is None:
+            self.msg = pstr
+            self.pstr = ""
+        else:
+            self.msg = msg
+            self.pstr = pstr
+        self.parserElement = elem
+        self.args = (pstr, loc, msg)
+
+    @classmethod
+    def _from_exception(cls, pe):
+        """
+        internal factory method to simplify creating one type of ParseException 
+        from another - avoids having __init__ signature conflicts among subclasses
+        """
+        return cls(pe.pstr, pe.loc, pe.msg, pe.parserElement)
+
+    def __getattr__( self, aname ):
+        """supported attributes by name are:
+            - lineno - returns the line number of the exception text
+            - col - returns the column number of the exception text
+            - line - returns the line containing the exception text
+        """
+        if( aname == "lineno" ):
+            return lineno( self.loc, self.pstr )
+        elif( aname in ("col", "column") ):
+            return col( self.loc, self.pstr )
+        elif( aname == "line" ):
+            return line( self.loc, self.pstr )
+        else:
+            raise AttributeError(aname)
+
+    def __str__( self ):
+        return "%s (at char %d), (line:%d, col:%d)" % \
+                ( self.msg, self.loc, self.lineno, self.column )
+    def __repr__( self ):
+        return _ustr(self)
+    def markInputline( self, markerString = ">!<" ):
+        """Extracts the exception line from the input string, and marks
+           the location of the exception with a special symbol.
+        """
+        line_str = self.line
+        line_column = self.column - 1
+        if markerString:
+            line_str = "".join((line_str[:line_column],
+                                markerString, line_str[line_column:]))
+        return line_str.strip()
+    def __dir__(self):
+        return "lineno col line".split() + dir(type(self))
+
+class ParseException(ParseBaseException):
+    """
+    Exception thrown when parse expressions don't match class;
+    supported attributes by name are:
+     - lineno - returns the line number of the exception text
+     - col - returns the column number of the exception text
+     - line - returns the line containing the exception text
+        
+    Example::
+        try:
+            Word(nums).setName("integer").parseString("ABC")
+        except ParseException as pe:
+            print(pe)
+            print("column: {}".format(pe.col))
+            
+    prints::
+       Expected integer (at char 0), (line:1, col:1)
+        column: 1
+    """
+    pass
+
+class ParseFatalException(ParseBaseException):
+    """user-throwable exception thrown when inconsistent parse content
+       is found; stops all parsing immediately"""
+    pass
+
+class ParseSyntaxException(ParseFatalException):
+    """just like L{ParseFatalException}, but thrown internally when an
+       L{ErrorStop<And._ErrorStop>} ('-' operator) indicates that parsing is to stop 
+       immediately because an unbacktrackable syntax error has been found"""
+    pass
+
+#~ class ReparseException(ParseBaseException):
+    #~ """Experimental class - parse actions can raise this exception to cause
+       #~ pyparsing to reparse the input string:
+        #~ - with a modified input string, and/or
+        #~ - with a modified start location
+       #~ Set the values of the ReparseException in the constructor, and raise the
+       #~ exception in a parse action to cause pyparsing to use the new string/location.
+       #~ Setting the values as None causes no change to be made.
+       #~ """
+    #~ def __init_( self, newstring, restartLoc ):
+        #~ self.newParseText = newstring
+        #~ self.reparseLoc = restartLoc
+
+class RecursiveGrammarException(Exception):
+    """exception thrown by L{ParserElement.validate} if the grammar could be improperly recursive"""
+    def __init__( self, parseElementList ):
+        self.parseElementTrace = parseElementList
+
+    def __str__( self ):
+        return "RecursiveGrammarException: %s" % self.parseElementTrace
+
+class _ParseResultsWithOffset(object):
+    def __init__(self,p1,p2):
+        self.tup = (p1,p2)
+    def __getitem__(self,i):
+        return self.tup[i]
+    def __repr__(self):
+        return repr(self.tup[0])
+    def setOffset(self,i):
+        self.tup = (self.tup[0],i)
+
+class ParseResults(object):
+    """
+    Structured parse results, to provide multiple means of access to the parsed data:
+       - as a list (C{len(results)})
+       - by list index (C{results[0], results[1]}, etc.)
+       - by attribute (C{results.<resultsName>} - see L{ParserElement.setResultsName})
+
+    Example::
+        integer = Word(nums)
+        date_str = (integer.setResultsName("year") + '/' 
+                        + integer.setResultsName("month") + '/' 
+                        + integer.setResultsName("day"))
+        # equivalent form:
+        # date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
+
+        # parseString returns a ParseResults object
+        result = date_str.parseString("1999/12/31")
+
+        def test(s, fn=repr):
+            print("%s -> %s" % (s, fn(eval(s))))
+        test("list(result)")
+        test("result[0]")
+        test("result['month']")
+        test("result.day")
+        test("'month' in result")
+        test("'minutes' in result")
+        test("result.dump()", str)
+    prints::
+        list(result) -> ['1999', '/', '12', '/', '31']
+        result[0] -> '1999'
+        result['month'] -> '12'
+        result.day -> '31'
+        'month' in result -> True
+        'minutes' in result -> False
+        result.dump() -> ['1999', '/', '12', '/', '31']
+        - day: 31
+        - month: 12
+        - year: 1999
+    """
+    def __new__(cls, toklist=None, name=None, asList=True, modal=True ):
+        if isinstance(toklist, cls):
+            return toklist
+        retobj = object.__new__(cls)
+        retobj.__doinit = True
+        return retobj
+
+    # Performance tuning: we construct a *lot* of these, so keep this
+    # constructor as small and fast as possible
+    def __init__( self, toklist=None, name=None, asList=True, modal=True, isinstance=isinstance ):
+        if self.__doinit:
+            self.__doinit = False
+            self.__name = None
+            self.__parent = None
+            self.__accumNames = {}
+            self.__asList = asList
+            self.__modal = modal
+            if toklist is None:
+                toklist = []
+            if isinstance(toklist, list):
+                self.__toklist = toklist[:]
+            elif isinstance(toklist, _generatorType):
+                self.__toklist = list(toklist)
+            else:
+                self.__toklist = [toklist]
+            self.__tokdict = dict()
+
+        if name is not None and name:
+            if not modal:
+                self.__accumNames[name] = 0
+            if isinstance(name,int):
+                name = _ustr(name) # will always return a str, but use _ustr for consistency
+            self.__name = name
+            if not (isinstance(toklist, (type(None), basestring, list)) and toklist in (None,'',[])):
+                if isinstance(toklist,basestring):
+                    toklist = [ toklist ]
+                if asList:
+                    if isinstance(toklist,ParseResults):
+                        self[name] = _ParseResultsWithOffset(toklist.copy(),0)
+                    else:
+                        self[name] = _ParseResultsWithOffset(ParseResults(toklist[0]),0)
+                    self[name].__name = name
+                else:
+                    try:
+                        self[name] = toklist[0]
+                    except (KeyError,TypeError,IndexError):
+                        self[name] = toklist
+
+    def __getitem__( self, i ):
+        if isinstance( i, (int,slice) ):
+            return self.__toklist[i]
+        else:
+            if i not in self.__accumNames:
+                return self.__tokdict[i][-1][0]
+            else:
+                return ParseResults([ v[0] for v in self.__tokdict[i] ])
+
+    def __setitem__( self, k, v, isinstance=isinstance ):
+        if isinstance(v,_ParseResultsWithOffset):
+            self.__tokdict[k] = self.__tokdict.get(k,list()) + [v]
+            sub = v[0]
+        elif isinstance(k,(int,slice)):
+            self.__toklist[k] = v
+            sub = v
+        else:
+            self.__tokdict[k] = self.__tokdict.get(k,list()) + [_ParseResultsWithOffset(v,0)]
+            sub = v
+        if isinstance(sub,ParseResults):
+            sub.__parent = wkref(self)
+
+    def __delitem__( self, i ):
+        if isinstance(i,(int,slice)):
+            mylen = len( self.__toklist )
+            del self.__toklist[i]
+
+            # convert int to slice
+            if isinstance(i, int):
+                if i < 0:
+                    i += mylen
+                i = slice(i, i+1)
+            # get removed indices
+            removed = list(range(*i.indices(mylen)))
+            removed.reverse()
+            # fixup indices in token dictionary
+            for name,occurrences in self.__tokdict.items():
+                for j in removed:
+                    for k, (value, position) in enumerate(occurrences):
+                        occurrences[k] = _ParseResultsWithOffset(value, position - (position > j))
+        else:
+            del self.__tokdict[i]
+
+    def __contains__( self, k ):
+        return k in self.__tokdict
+
+    def __len__( self ): return len( self.__toklist )
+    def __bool__(self): return ( not not self.__toklist )
+    __nonzero__ = __bool__
+    def __iter__( self ): return iter( self.__toklist )
+    def __reversed__( self ): return iter( self.__toklist[::-1] )
+    def _iterkeys( self ):
+        if hasattr(self.__tokdict, "iterkeys"):
+            return self.__tokdict.iterkeys()
+        else:
+            return iter(self.__tokdict)
+
+    def _itervalues( self ):
+        return (self[k] for k in self._iterkeys())
+            
+    def _iteritems( self ):
+        return ((k, self[k]) for k in self._iterkeys())
+
+    if PY_3:
+        keys = _iterkeys       
+        """Returns an iterator of all named result keys (Python 3.x only)."""
+
+        values = _itervalues
+        """Returns an iterator of all named result values (Python 3.x only)."""
+
+        items = _iteritems
+        """Returns an iterator of all named result key-value tuples (Python 3.x only)."""
+
+    else:
+        iterkeys = _iterkeys
+        """Returns an iterator of all named result keys (Python 2.x only)."""
+
+        itervalues = _itervalues
+        """Returns an iterator of all named result values (Python 2.x only)."""
+
+        iteritems = _iteritems
+        """Returns an iterator of all named result key-value tuples (Python 2.x only)."""
+
+        def keys( self ):
+            """Returns all named result keys (as a list in Python 2.x, as an iterator in Python 3.x)."""
+            return list(self.iterkeys())
+
+        def values( self ):
+            """Returns all named result values (as a list in Python 2.x, as an iterator in Python 3.x)."""
+            return list(self.itervalues())
+                
+        def items( self ):
+            """Returns all named result key-values (as a list of tuples in Python 2.x, as an iterator in Python 3.x)."""
+            return list(self.iteritems())
+
+    def haskeys( self ):
+        """Since keys() returns an iterator, this method is helpful in bypassing
+           code that looks for the existence of any defined results names."""
+        return bool(self.__tokdict)
+        
+    def pop( self, *args, **kwargs):
+        """
+        Removes and returns item at specified index (default=C{last}).
+        Supports both C{list} and C{dict} semantics for C{pop()}. If passed no
+        argument or an integer argument, it will use C{list} semantics
+        and pop tokens from the list of parsed tokens. If passed a 
+        non-integer argument (most likely a string), it will use C{dict}
+        semantics and pop the corresponding value from any defined 
+        results names. A second default return value argument is 
+        supported, just as in C{dict.pop()}.
+
+        Example::
+            def remove_first(tokens):
+                tokens.pop(0)
+            print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321']
+            print(OneOrMore(Word(nums)).addParseAction(remove_first).parseString("0 123 321")) # -> ['123', '321']
+
+            label = Word(alphas)
+            patt = label("LABEL") + OneOrMore(Word(nums))
+            print(patt.parseString("AAB 123 321").dump())
+
+            # Use pop() in a parse action to remove named result (note that corresponding value is not
+            # removed from list form of results)
+            def remove_LABEL(tokens):
+                tokens.pop("LABEL")
+                return tokens
+            patt.addParseAction(remove_LABEL)
+            print(patt.parseString("AAB 123 321").dump())
+        prints::
+            ['AAB', '123', '321']
+            - LABEL: AAB
+
+            ['AAB', '123', '321']
+        """
+        if not args:
+            args = [-1]
+        for k,v in kwargs.items():
+            if k == 'default':
+                args = (args[0], v)
+            else:
+                raise TypeError("pop() got an unexpected keyword argument '%s'" % k)
+        if (isinstance(args[0], int) or 
+                        len(args) == 1 or 
+                        args[0] in self):
+            index = args[0]
+            ret = self[index]
+            del self[index]
+            return ret
+        else:
+            defaultvalue = args[1]
+            return defaultvalue
+
+    def get(self, key, defaultValue=None):
+        """
+        Returns named result matching the given key, or if there is no
+        such name, then returns the given C{defaultValue} or C{None} if no
+        C{defaultValue} is specified.
+
+        Similar to C{dict.get()}.
+        
+        Example::
+            integer = Word(nums)
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")           
+
+            result = date_str.parseString("1999/12/31")
+            print(result.get("year")) # -> '1999'
+            print(result.get("hour", "not specified")) # -> 'not specified'
+            print(result.get("hour")) # -> None
+        """
+        if key in self:
+            return self[key]
+        else:
+            return defaultValue
+
+    def insert( self, index, insStr ):
+        """
+        Inserts new element at location index in the list of parsed tokens.
+        
+        Similar to C{list.insert()}.
+
+        Example::
+            print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321']
+
+            # use a parse action to insert the parse location in the front of the parsed results
+            def insert_locn(locn, tokens):
+                tokens.insert(0, locn)
+            print(OneOrMore(Word(nums)).addParseAction(insert_locn).parseString("0 123 321")) # -> [0, '0', '123', '321']
+        """
+        self.__toklist.insert(index, insStr)
+        # fixup indices in token dictionary
+        for name,occurrences in self.__tokdict.items():
+            for k, (value, position) in enumerate(occurrences):
+                occurrences[k] = _ParseResultsWithOffset(value, position + (position > index))
+
+    def append( self, item ):
+        """
+        Add single element to end of ParseResults list of elements.
+
+        Example::
+            print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321']
+            
+            # use a parse action to compute the sum of the parsed integers, and add it to the end
+            def append_sum(tokens):
+                tokens.append(sum(map(int, tokens)))
+            print(OneOrMore(Word(nums)).addParseAction(append_sum).parseString("0 123 321")) # -> ['0', '123', '321', 444]
+        """
+        self.__toklist.append(item)
+
+    def extend( self, itemseq ):
+        """
+        Add sequence of elements to end of ParseResults list of elements.
+
+        Example::
+            patt = OneOrMore(Word(alphas))
+            
+            # use a parse action to append the reverse of the matched strings, to make a palindrome
+            def make_palindrome(tokens):
+                tokens.extend(reversed([t[::-1] for t in tokens]))
+                return ''.join(tokens)
+            print(patt.addParseAction(make_palindrome).parseString("lskdj sdlkjf lksd")) # -> 'lskdjsdlkjflksddsklfjkldsjdksl'
+        """
+        if isinstance(itemseq, ParseResults):
+            self += itemseq
+        else:
+            self.__toklist.extend(itemseq)
+
+    def clear( self ):
+        """
+        Clear all elements and results names.
+        """
+        del self.__toklist[:]
+        self.__tokdict.clear()
+
+    def __getattr__( self, name ):
+        try:
+            return self[name]
+        except KeyError:
+            return ""
+            
+        if name in self.__tokdict:
+            if name not in self.__accumNames:
+                return self.__tokdict[name][-1][0]
+            else:
+                return ParseResults([ v[0] for v in self.__tokdict[name] ])
+        else:
+            return ""
+
+    def __add__( self, other ):
+        ret = self.copy()
+        ret += other
+        return ret
+
+    def __iadd__( self, other ):
+        if other.__tokdict:
+            offset = len(self.__toklist)
+            addoffset = lambda a: offset if a<0 else a+offset
+            otheritems = other.__tokdict.items()
+            otherdictitems = [(k, _ParseResultsWithOffset(v[0],addoffset(v[1])) )
+                                for (k,vlist) in otheritems for v in vlist]
+            for k,v in otherdictitems:
+                self[k] = v
+                if isinstance(v[0],ParseResults):
+                    v[0].__parent = wkref(self)
+            
+        self.__toklist += other.__toklist
+        self.__accumNames.update( other.__accumNames )
+        return self
+
+    def __radd__(self, other):
+        if isinstance(other,int) and other == 0:
+            # useful for merging many ParseResults using sum() builtin
+            return self.copy()
+        else:
+            # this may raise a TypeError - so be it
+            return other + self
+        
+    def __repr__( self ):
+        return "(%s, %s)" % ( repr( self.__toklist ), repr( self.__tokdict ) )
+
+    def __str__( self ):
+        return '[' + ', '.join(_ustr(i) if isinstance(i, ParseResults) else repr(i) for i in self.__toklist) + ']'
+
+    def _asStringList( self, sep='' ):
+        out = []
+        for item in self.__toklist:
+            if out and sep:
+                out.append(sep)
+            if isinstance( item, ParseResults ):
+                out += item._asStringList()
+            else:
+                out.append( _ustr(item) )
+        return out
+
+    def asList( self ):
+        """
+        Returns the parse results as a nested list of matching tokens, all converted to strings.
+
+        Example::
+            patt = OneOrMore(Word(alphas))
+            result = patt.parseString("sldkj lsdkj sldkj")
+            # even though the result prints in string-like form, it is actually a pyparsing ParseResults
+            print(type(result), result) # -> <class 'pyparsing.ParseResults'> ['sldkj', 'lsdkj', 'sldkj']
+            
+            # Use asList() to create an actual list
+            result_list = result.asList()
+            print(type(result_list), result_list) # -> <class 'list'> ['sldkj', 'lsdkj', 'sldkj']
+        """
+        return [res.asList() if isinstance(res,ParseResults) else res for res in self.__toklist]
+
+    def asDict( self ):
+        """
+        Returns the named parse results as a nested dictionary.
+
+        Example::
+            integer = Word(nums)
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
+            
+            result = date_str.parseString('12/31/1999')
+            print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
+            
+            result_dict = result.asDict()
+            print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}
+
+            # even though a ParseResults supports dict-like access, sometime you just need to have a dict
+            import json
+            print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
+            print(json.dumps(result.asDict())) # -> {"month": "31", "day": "1999", "year": "12"}
+        """
+        if PY_3:
+            item_fn = self.items
+        else:
+            item_fn = self.iteritems
+            
+        def toItem(obj):
+            if isinstance(obj, ParseResults):
+                if obj.haskeys():
+                    return obj.asDict()
+                else:
+                    return [toItem(v) for v in obj]
+            else:
+                return obj
+                
+        return dict((k,toItem(v)) for k,v in item_fn())
+
+    def copy( self ):
+        """
+        Returns a new copy of a C{ParseResults} object.
+        """
+        ret = ParseResults( self.__toklist )
+        ret.__tokdict = self.__tokdict.copy()
+        ret.__parent = self.__parent
+        ret.__accumNames.update( self.__accumNames )
+        ret.__name = self.__name
+        return ret
+
+    def asXML( self, doctag=None, namedItemsOnly=False, indent="", formatted=True ):
+        """
+        (Deprecated) Returns the parse results as XML. Tags are created for tokens and lists that have defined results names.
+        """
+        nl = "\n"
+        out = []
+        namedItems = dict((v[1],k) for (k,vlist) in self.__tokdict.items()
+                                                            for v in vlist)
+        nextLevelIndent = indent + "  "
+
+        # collapse out indents if formatting is not desired
+        if not formatted:
+            indent = ""
+            nextLevelIndent = ""
+            nl = ""
+
+        selfTag = None
+        if doctag is not None:
+            selfTag = doctag
+        else:
+            if self.__name:
+                selfTag = self.__name
+
+        if not selfTag:
+            if namedItemsOnly:
+                return ""
+            else:
+                selfTag = "ITEM"
+
+        out += [ nl, indent, "<", selfTag, ">" ]
+
+        for i,res in enumerate(self.__toklist):
+            if isinstance(res,ParseResults):
+                if i in namedItems:
+                    out += [ res.asXML(namedItems[i],
+                                        namedItemsOnly and doctag is None,
+                                        nextLevelIndent,
+                                        formatted)]
+                else:
+                    out += [ res.asXML(None,
+                                        namedItemsOnly and doctag is None,
+                                        nextLevelIndent,
+                                        formatted)]
+            else:
+                # individual token, see if there is a name for it
+                resTag = None
+                if i in namedItems:
+                    resTag = namedItems[i]
+                if not resTag:
+                    if namedItemsOnly:
+                        continue
+                    else:
+                        resTag = "ITEM"
+                xmlBodyText = _xml_escape(_ustr(res))
+                out += [ nl, nextLevelIndent, "<", resTag, ">",
+                                                xmlBodyText,
+                                                "</", resTag, ">" ]
+
+        out += [ nl, indent, "</", selfTag, ">" ]
+        return "".join(out)
+
+    def __lookup(self,sub):
+        for k,vlist in self.__tokdict.items():
+            for v,loc in vlist:
+                if sub is v:
+                    return k
+        return None
+
+    def getName(self):
+        r"""
+        Returns the results name for this token expression. Useful when several 
+        different expressions might match at a particular location.
+
+        Example::
+            integer = Word(nums)
+            ssn_expr = Regex(r"\d\d\d-\d\d-\d\d\d\d")
+            house_number_expr = Suppress('#') + Word(nums, alphanums)
+            user_data = (Group(house_number_expr)("house_number") 
+                        | Group(ssn_expr)("ssn")
+                        | Group(integer)("age"))
+            user_info = OneOrMore(user_data)
+            
+            result = user_info.parseString("22 111-22-3333 #221B")
+            for item in result:
+                print(item.getName(), ':', item[0])
+        prints::
+            age : 22
+            ssn : 111-22-3333
+            house_number : 221B
+        """
+        if self.__name:
+            return self.__name
+        elif self.__parent:
+            par = self.__parent()
+            if par:
+                return par.__lookup(self)
+            else:
+                return None
+        elif (len(self) == 1 and
+               len(self.__tokdict) == 1 and
+               next(iter(self.__tokdict.values()))[0][1] in (0,-1)):
+            return next(iter(self.__tokdict.keys()))
+        else:
+            return None
+
+    def dump(self, indent='', depth=0, full=True):
+        """
+        Diagnostic method for listing out the contents of a C{ParseResults}.
+        Accepts an optional C{indent} argument so that this string can be embedded
+        in a nested display of other data.
+
+        Example::
+            integer = Word(nums)
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
+            
+            result = date_str.parseString('12/31/1999')
+            print(result.dump())
+        prints::
+            ['12', '/', '31', '/', '1999']
+            - day: 1999
+            - month: 31
+            - year: 12
+        """
+        out = []
+        NL = '\n'
+        out.append( indent+_ustr(self.asList()) )
+        if full:
+            if self.haskeys():
+                items = sorted((str(k), v) for k,v in self.items())
+                for k,v in items:
+                    if out:
+                        out.append(NL)
+                    out.append( "%s%s- %s: " % (indent,('  '*depth), k) )
+                    if isinstance(v,ParseResults):
+                        if v:
+                            out.append( v.dump(indent,depth+1) )
+                        else:
+                            out.append(_ustr(v))
+                    else:
+                        out.append(repr(v))
+            elif any(isinstance(vv,ParseResults) for vv in self):
+                v = self
+                for i,vv in enumerate(v):
+                    if isinstance(vv,ParseResults):
+                        out.append("\n%s%s[%d]:\n%s%s%s" % (indent,('  '*(depth)),i,indent,('  '*(depth+1)),vv.dump(indent,depth+1) ))
+                    else:
+                        out.append("\n%s%s[%d]:\n%s%s%s" % (indent,('  '*(depth)),i,indent,('  '*(depth+1)),_ustr(vv)))
+            
+        return "".join(out)
+
+    def pprint(self, *args, **kwargs):
+        """
+        Pretty-printer for parsed results as a list, using the C{pprint} module.
+        Accepts additional positional or keyword args as defined for the 
+        C{pprint.pprint} method. (U{http://docs.python.org/3/library/pprint.html#pprint.pprint})
+
+        Example::
+            ident = Word(alphas, alphanums)
+            num = Word(nums)
+            func = Forward()
+            term = ident | num | Group('(' + func + ')')
+            func <<= ident + Group(Optional(delimitedList(term)))
+            result = func.parseString("fna a,b,(fnb c,d,200),100")
+            result.pprint(width=40)
+        prints::
+            ['fna',
+             ['a',
+              'b',
+              ['(', 'fnb', ['c', 'd', '200'], ')'],
+              '100']]
+        """
+        pprint.pprint(self.asList(), *args, **kwargs)
+
+    # add support for pickle protocol
+    def __getstate__(self):
+        return ( self.__toklist,
+                 ( self.__tokdict.copy(),
+                   self.__parent is not None and self.__parent() or None,
+                   self.__accumNames,
+                   self.__name ) )
+
+    def __setstate__(self,state):
+        self.__toklist = state[0]
+        (self.__tokdict,
+         par,
+         inAccumNames,
+         self.__name) = state[1]
+        self.__accumNames = {}
+        self.__accumNames.update(inAccumNames)
+        if par is not None:
+            self.__parent = wkref(par)
+        else:
+            self.__parent = None
+
+    def __getnewargs__(self):
+        return self.__toklist, self.__name, self.__asList, self.__modal
+
+    def __dir__(self):
+        return (dir(type(self)) + list(self.keys()))
+
+MutableMapping.register(ParseResults)
+
+def col (loc,strg):
+    """Returns current column within a string, counting newlines as line separators.
+   The first column is number 1.
+
+   Note: the default parsing behavior is to expand tabs in the input string
+   before starting the parsing process.  See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information
+   on parsing strings containing C{<TAB>}s, and suggested methods to maintain a
+   consistent view of the parsed string, the parse location, and line and column
+   positions within the parsed string.
+   """
+    s = strg
+    return 1 if 0<loc<len(s) and s[loc-1] == '\n' else loc - s.rfind("\n", 0, loc)
+
+def lineno(loc,strg):
+    """Returns current line number within a string, counting newlines as line separators.
+   The first line is number 1.
+
+   Note: the default parsing behavior is to expand tabs in the input string
+   before starting the parsing process.  See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information
+   on parsing strings containing C{<TAB>}s, and suggested methods to maintain a
+   consistent view of the parsed string, the parse location, and line and column
+   positions within the parsed string.
+   """
+    return strg.count("\n",0,loc) + 1
+
+def line( loc, strg ):
+    """Returns the line of text containing loc within a string, counting newlines as line separators.
+       """
+    lastCR = strg.rfind("\n", 0, loc)
+    nextCR = strg.find("\n", loc)
+    if nextCR >= 0:
+        return strg[lastCR+1:nextCR]
+    else:
+        return strg[lastCR+1:]
+
+def _defaultStartDebugAction( instring, loc, expr ):
+    print (("Match " + _ustr(expr) + " at loc " + _ustr(loc) + "(%d,%d)" % ( lineno(loc,instring), col(loc,instring) )))
+
+def _defaultSuccessDebugAction( instring, startloc, endloc, expr, toks ):
+    print ("Matched " + _ustr(expr) + " -> " + str(toks.asList()))
+
+def _defaultExceptionDebugAction( instring, loc, expr, exc ):
+    print ("Exception raised:" + _ustr(exc))
+
+def nullDebugAction(*args):
+    """'Do-nothing' debug action, to suppress debugging output during parsing."""
+    pass
+
+# Only works on Python 3.x - nonlocal is toxic to Python 2 installs
+#~ 'decorator to trim function calls to match the arity of the target'
+#~ def _trim_arity(func, maxargs=3):
+    #~ if func in singleArgBuiltins:
+        #~ return lambda s,l,t: func(t)
+    #~ limit = 0
+    #~ foundArity = False
+    #~ def wrapper(*args):
+        #~ nonlocal limit,foundArity
+        #~ while 1:
+            #~ try:
+                #~ ret = func(*args[limit:])
+                #~ foundArity = True
+                #~ return ret
+            #~ except TypeError:
+                #~ if limit == maxargs or foundArity:
+                    #~ raise
+                #~ limit += 1
+                #~ continue
+    #~ return wrapper
+
+# this version is Python 2.x-3.x cross-compatible
+'decorator to trim function calls to match the arity of the target'
+def _trim_arity(func, maxargs=2):
+    if func in singleArgBuiltins:
+        return lambda s,l,t: func(t)
+    limit = [0]
+    foundArity = [False]
+    
+    # traceback return data structure changed in Py3.5 - normalize back to plain tuples
+    if system_version[:2] >= (3,5):
+        def extract_stack(limit=0):
+            # special handling for Python 3.5.0 - extra deep call stack by 1
+            offset = -3 if system_version == (3,5,0) else -2
+            frame_summary = traceback.extract_stack(limit=-offset+limit-1)[offset]
+            return [frame_summary[:2]]
+        def extract_tb(tb, limit=0):
+            frames = traceback.extract_tb(tb, limit=limit)
+            frame_summary = frames[-1]
+            return [frame_summary[:2]]
+    else:
+        extract_stack = traceback.extract_stack
+        extract_tb = traceback.extract_tb
+    
+    # synthesize what would be returned by traceback.extract_stack at the call to 
+    # user's parse action 'func', so that we don't incur call penalty at parse time
+    
+    LINE_DIFF = 6
+    # IF ANY CODE CHANGES, EVEN JUST COMMENTS OR BLANK LINES, BETWEEN THE NEXT LINE AND 
+    # THE CALL TO FUNC INSIDE WRAPPER, LINE_DIFF MUST BE MODIFIED!!!!
+    this_line = extract_stack(limit=2)[-1]
+    pa_call_line_synth = (this_line[0], this_line[1]+LINE_DIFF)
+
+    def wrapper(*args):
+        while 1:
+            try:
+                ret = func(*args[limit[0]:])
+                foundArity[0] = True
+                return ret
+            except TypeError:
+                # re-raise TypeErrors if they did not come from our arity testing
+                if foundArity[0]:
+                    raise
+                else:
+                    try:
+                        tb = sys.exc_info()[-1]
+                        if not extract_tb(tb, limit=2)[-1][:2] == pa_call_line_synth:
+                            raise
+                    finally:
+                        del tb
+
+                if limit[0] <= maxargs:
+                    limit[0] += 1
+                    continue
+                raise
+
+    # copy func name to wrapper for sensible debug output
+    func_name = "<parse action>"
+    try:
+        func_name = getattr(func, '__name__', 
+                            getattr(func, '__class__').__name__)
+    except Exception:
+        func_name = str(func)
+    wrapper.__name__ = func_name
+
+    return wrapper
+
+class ParserElement(object):
+    """Abstract base level parser element class."""
+    DEFAULT_WHITE_CHARS = " \n\t\r"
+    verbose_stacktrace = False
+
+    @staticmethod
+    def setDefaultWhitespaceChars( chars ):
+        r"""
+        Overrides the default whitespace chars
+
+        Example::
+            # default whitespace chars are space, <TAB> and newline
+            OneOrMore(Word(alphas)).parseString("abc def\nghi jkl")  # -> ['abc', 'def', 'ghi', 'jkl']
+            
+            # change to just treat newline as significant
+            ParserElement.setDefaultWhitespaceChars(" \t")
+            OneOrMore(Word(alphas)).parseString("abc def\nghi jkl")  # -> ['abc', 'def']
+        """
+        ParserElement.DEFAULT_WHITE_CHARS = chars
+
+    @staticmethod
+    def inlineLiteralsUsing(cls):
+        """
+        Set class to be used for inclusion of string literals into a parser.
+        
+        Example::
+            # default literal class used is Literal
+            integer = Word(nums)
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")           
+
+            date_str.parseString("1999/12/31")  # -> ['1999', '/', '12', '/', '31']
+
+
+            # change to Suppress
+            ParserElement.inlineLiteralsUsing(Suppress)
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")           
+
+            date_str.parseString("1999/12/31")  # -> ['1999', '12', '31']
+        """
+        ParserElement._literalStringClass = cls
+
+    def __init__( self, savelist=False ):
+        self.parseAction = list()
+        self.failAction = None
+        #~ self.name = "<unknown>"  # don't define self.name, let subclasses try/except upcall
+        self.strRepr = None
+        self.resultsName = None
+        self.saveAsList = savelist
+        self.skipWhitespace = True
+        self.whiteChars = ParserElement.DEFAULT_WHITE_CHARS
+        self.copyDefaultWhiteChars = True
+        self.mayReturnEmpty = False # used when checking for left-recursion
+        self.keepTabs = False
+        self.ignoreExprs = list()
+        self.debug = False
+        self.streamlined = False
+        self.mayIndexError = True # used to optimize exception handling for subclasses that don't advance parse index
+        self.errmsg = ""
+        self.modalResults = True # used to mark results names as modal (report only last) or cumulative (list all)
+        self.debugActions = ( None, None, None ) #custom debug actions
+        self.re = None
+        self.callPreparse = True # used to avoid redundant calls to preParse
+        self.callDuringTry = False
+
+    def copy( self ):
+        """
+        Make a copy of this C{ParserElement}.  Useful for defining different parse actions
+        for the same parsing pattern, using copies of the original parse element.
+        
+        Example::
+            integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
+            integerK = integer.copy().addParseAction(lambda toks: toks[0]*1024) + Suppress("K")
+            integerM = integer.copy().addParseAction(lambda toks: toks[0]*1024*1024) + Suppress("M")
+            
+            print(OneOrMore(integerK | integerM | integer).parseString("5K 100 640K 256M"))
+        prints::
+            [5120, 100, 655360, 268435456]
+        Equivalent form of C{expr.copy()} is just C{expr()}::
+            integerM = integer().addParseAction(lambda toks: toks[0]*1024*1024) + Suppress("M")
+        """
+        cpy = copy.copy( self )
+        cpy.parseAction = self.parseAction[:]
+        cpy.ignoreExprs = self.ignoreExprs[:]
+        if self.copyDefaultWhiteChars:
+            cpy.whiteChars = ParserElement.DEFAULT_WHITE_CHARS
+        return cpy
+
+    def setName( self, name ):
+        """
+        Define name for this expression, makes debugging and exception messages clearer.
+        
+        Example::
+            Word(nums).parseString("ABC")  # -> Exception: Expected W:(0123...) (at char 0), (line:1, col:1)
+            Word(nums).setName("integer").parseString("ABC")  # -> Exception: Expected integer (at char 0), (line:1, col:1)
+        """
+        self.name = name
+        self.errmsg = "Expected " + self.name
+        if hasattr(self,"exception"):
+            self.exception.msg = self.errmsg
+        return self
+
+    def setResultsName( self, name, listAllMatches=False ):
+        """
+        Define name for referencing matching tokens as a nested attribute
+        of the returned parse results.
+        NOTE: this returns a *copy* of the original C{ParserElement} object;
+        this is so that the client can define a basic element, such as an
+        integer, and reference it in multiple places with different names.
+
+        You can also set results names using the abbreviated syntax,
+        C{expr("name")} in place of C{expr.setResultsName("name")} - 
+        see L{I{__call__}<__call__>}.
+
+        Example::
+            date_str = (integer.setResultsName("year") + '/' 
+                        + integer.setResultsName("month") + '/' 
+                        + integer.setResultsName("day"))
+
+            # equivalent form:
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
+        """
+        newself = self.copy()
+        if name.endswith("*"):
+            name = name[:-1]
+            listAllMatches=True
+        newself.resultsName = name
+        newself.modalResults = not listAllMatches
+        return newself
+
+    def setBreak(self,breakFlag = True):
+        """Method to invoke the Python pdb debugger when this element is
+           about to be parsed. Set C{breakFlag} to True to enable, False to
+           disable.
+        """
+        if breakFlag:
+            _parseMethod = self._parse
+            def breaker(instring, loc, doActions=True, callPreParse=True):
+                import pdb
+                pdb.set_trace()
+                return _parseMethod( instring, loc, doActions, callPreParse )
+            breaker._originalParseMethod = _parseMethod
+            self._parse = breaker
+        else:
+            if hasattr(self._parse,"_originalParseMethod"):
+                self._parse = self._parse._originalParseMethod
+        return self
+
+    def setParseAction( self, *fns, **kwargs ):
+        """
+        Define one or more actions to perform when successfully matching parse element definition.
+        Parse action fn is a callable method with 0-3 arguments, called as C{fn(s,loc,toks)},
+        C{fn(loc,toks)}, C{fn(toks)}, or just C{fn()}, where:
+         - s   = the original string being parsed (see note below)
+         - loc = the location of the matching substring
+         - toks = a list of the matched tokens, packaged as a C{L{ParseResults}} object
+        If the functions in fns modify the tokens, they can return them as the return
+        value from fn, and the modified list of tokens will replace the original.
+        Otherwise, fn does not need to return any value.
+
+        Optional keyword arguments:
+         - callDuringTry = (default=C{False}) indicate if parse action should be run during lookaheads and alternate testing
+
+        Note: the default parsing behavior is to expand tabs in the input string
+        before starting the parsing process.  See L{I{parseString}<parseString>} for more information
+        on parsing strings containing C{<TAB>}s, and suggested methods to maintain a
+        consistent view of the parsed string, the parse location, and line and column
+        positions within the parsed string.
+        
+        Example::
+            integer = Word(nums)
+            date_str = integer + '/' + integer + '/' + integer
+
+            date_str.parseString("1999/12/31")  # -> ['1999', '/', '12', '/', '31']
+
+            # use parse action to convert to ints at parse time
+            integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
+            date_str = integer + '/' + integer + '/' + integer
+
+            # note that integer fields are now ints, not strings
+            date_str.parseString("1999/12/31")  # -> [1999, '/', 12, '/', 31]
+        """
+        self.parseAction = list(map(_trim_arity, list(fns)))
+        self.callDuringTry = kwargs.get("callDuringTry", False)
+        return self
+
+    def addParseAction( self, *fns, **kwargs ):
+        """
+        Add one or more parse actions to expression's list of parse actions. See L{I{setParseAction}<setParseAction>}.
+        
+        See examples in L{I{copy}<copy>}.
+        """
+        self.parseAction += list(map(_trim_arity, list(fns)))
+        self.callDuringTry = self.callDuringTry or kwargs.get("callDuringTry", False)
+        return self
+
+    def addCondition(self, *fns, **kwargs):
+        """Add a boolean predicate function to expression's list of parse actions. See 
+        L{I{setParseAction}<setParseAction>} for function call signatures. Unlike C{setParseAction}, 
+        functions passed to C{addCondition} need to return boolean success/fail of the condition.
+
+        Optional keyword arguments:
+         - message = define a custom message to be used in the raised exception
+         - fatal   = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise ParseException
+         
+        Example::
+            integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
+            year_int = integer.copy()
+            year_int.addCondition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
+            date_str = year_int + '/' + integer + '/' + integer
+
+            result = date_str.parseString("1999/12/31")  # -> Exception: Only support years 2000 and later (at char 0), (line:1, col:1)
+        """
+        msg = kwargs.get("message", "failed user-defined condition")
+        exc_type = ParseFatalException if kwargs.get("fatal", False) else ParseException
+        for fn in fns:
+            def pa(s,l,t):
+                if not bool(_trim_arity(fn)(s,l,t)):
+                    raise exc_type(s,l,msg)
+            self.parseAction.append(pa)
+        self.callDuringTry = self.callDuringTry or kwargs.get("callDuringTry", False)
+        return self
+
+    def setFailAction( self, fn ):
+        """Define action to perform if parsing fails at this expression.
+           Fail acton fn is a callable function that takes the arguments
+           C{fn(s,loc,expr,err)} where:
+            - s = string being parsed
+            - loc = location where expression match was attempted and failed
+            - expr = the parse expression that failed
+            - err = the exception thrown
+           The function returns no value.  It may throw C{L{ParseFatalException}}
+           if it is desired to stop parsing immediately."""
+        self.failAction = fn
+        return self
+
+    def _skipIgnorables( self, instring, loc ):
+        exprsFound = True
+        while exprsFound:
+            exprsFound = False
+            for e in self.ignoreExprs:
+                try:
+                    while 1:
+                        loc,dummy = e._parse( instring, loc )
+                        exprsFound = True
+                except ParseException:
+                    pass
+        return loc
+
+    def preParse( self, instring, loc ):
+        if self.ignoreExprs:
+            loc = self._skipIgnorables( instring, loc )
+
+        if self.skipWhitespace:
+            wt = self.whiteChars
+            instrlen = len(instring)
+            while loc < instrlen and instring[loc] in wt:
+                loc += 1
+
+        return loc
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        return loc, []
+
+    def postParse( self, instring, loc, tokenlist ):
+        return tokenlist
+
+    #~ @profile
+    def _parseNoCache( self, instring, loc, doActions=True, callPreParse=True ):
+        debugging = ( self.debug ) #and doActions )
+
+        if debugging or self.failAction:
+            #~ print ("Match",self,"at loc",loc,"(%d,%d)" % ( lineno(loc,instring), col(loc,instring) ))
+            if (self.debugActions[0] ):
+                self.debugActions[0]( instring, loc, self )
+            if callPreParse and self.callPreparse:
+                preloc = self.preParse( instring, loc )
+            else:
+                preloc = loc
+            tokensStart = preloc
+            try:
+                try:
+                    loc,tokens = self.parseImpl( instring, preloc, doActions )
+                except IndexError:
+                    raise ParseException( instring, len(instring), self.errmsg, self )
+            except ParseBaseException as err:
+                #~ print ("Exception raised:", err)
+                if self.debugActions[2]:
+                    self.debugActions[2]( instring, tokensStart, self, err )
+                if self.failAction:
+                    self.failAction( instring, tokensStart, self, err )
+                raise
+        else:
+            if callPreParse and self.callPreparse:
+                preloc = self.preParse( instring, loc )
+            else:
+                preloc = loc
+            tokensStart = preloc
+            if self.mayIndexError or preloc >= len(instring):
+                try:
+                    loc,tokens = self.parseImpl( instring, preloc, doActions )
+                except IndexError:
+                    raise ParseException( instring, len(instring), self.errmsg, self )
+            else:
+                loc,tokens = self.parseImpl( instring, preloc, doActions )
+
+        tokens = self.postParse( instring, loc, tokens )
+
+        retTokens = ParseResults( tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults )
+        if self.parseAction and (doActions or self.callDuringTry):
+            if debugging:
+                try:
+                    for fn in self.parseAction:
+                        tokens = fn( instring, tokensStart, retTokens )
+                        if tokens is not None:
+                            retTokens = ParseResults( tokens,
+                                                      self.resultsName,
+                                                      asList=self.saveAsList and isinstance(tokens,(ParseResults,list)),
+                                                      modal=self.modalResults )
+                except ParseBaseException as err:
+                    #~ print "Exception raised in user parse action:", err
+                    if (self.debugActions[2] ):
+                        self.debugActions[2]( instring, tokensStart, self, err )
+                    raise
+            else:
+                for fn in self.parseAction:
+                    tokens = fn( instring, tokensStart, retTokens )
+                    if tokens is not None:
+                        retTokens = ParseResults( tokens,
+                                                  self.resultsName,
+                                                  asList=self.saveAsList and isinstance(tokens,(ParseResults,list)),
+                                                  modal=self.modalResults )
+        if debugging:
+            #~ print ("Matched",self,"->",retTokens.asList())
+            if (self.debugActions[1] ):
+                self.debugActions[1]( instring, tokensStart, loc, self, retTokens )
+
+        return loc, retTokens
+
+    def tryParse( self, instring, loc ):
+        try:
+            return self._parse( instring, loc, doActions=False )[0]
+        except ParseFatalException:
+            raise ParseException( instring, loc, self.errmsg, self)
+    
+    def canParseNext(self, instring, loc):
+        try:
+            self.tryParse(instring, loc)
+        except (ParseException, IndexError):
+            return False
+        else:
+            return True
+
+    class _UnboundedCache(object):
+        def __init__(self):
+            cache = {}
+            self.not_in_cache = not_in_cache = object()
+
+            def get(self, key):
+                return cache.get(key, not_in_cache)
+
+            def set(self, key, value):
+                cache[key] = value
+
+            def clear(self):
+                cache.clear()
+                
+            def cache_len(self):
+                return len(cache)
+
+            self.get = types.MethodType(get, self)
+            self.set = types.MethodType(set, self)
+            self.clear = types.MethodType(clear, self)
+            self.__len__ = types.MethodType(cache_len, self)
+
+    if _OrderedDict is not None:
+        class _FifoCache(object):
+            def __init__(self, size):
+                self.not_in_cache = not_in_cache = object()
+
+                cache = _OrderedDict()
+
+                def get(self, key):
+                    return cache.get(key, not_in_cache)
+
+                def set(self, key, value):
+                    cache[key] = value
+                    while len(cache) > size:
+                        try:
+                            cache.popitem(False)
+                        except KeyError:
+                            pass
+
+                def clear(self):
+                    cache.clear()
+
+                def cache_len(self):
+                    return len(cache)
+
+                self.get = types.MethodType(get, self)
+                self.set = types.MethodType(set, self)
+                self.clear = types.MethodType(clear, self)
+                self.__len__ = types.MethodType(cache_len, self)
+
+    else:
+        class _FifoCache(object):
+            def __init__(self, size):
+                self.not_in_cache = not_in_cache = object()
+
+                cache = {}
+                key_fifo = collections.deque([], size)
+
+                def get(self, key):
+                    return cache.get(key, not_in_cache)
+
+                def set(self, key, value):
+                    cache[key] = value
+                    while len(key_fifo) > size:
+                        cache.pop(key_fifo.popleft(), None)
+                    key_fifo.append(key)
+
+                def clear(self):
+                    cache.clear()
+                    key_fifo.clear()
+
+                def cache_len(self):
+                    return len(cache)
+
+                self.get = types.MethodType(get, self)
+                self.set = types.MethodType(set, self)
+                self.clear = types.MethodType(clear, self)
+                self.__len__ = types.MethodType(cache_len, self)
+
+    # argument cache for optimizing repeated calls when backtracking through recursive expressions
+    packrat_cache = {} # this is set later by enabledPackrat(); this is here so that resetCache() doesn't fail
+    packrat_cache_lock = RLock()
+    packrat_cache_stats = [0, 0]
+
+    # this method gets repeatedly called during backtracking with the same arguments -
+    # we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
+    def _parseCache( self, instring, loc, doActions=True, callPreParse=True ):
+        HIT, MISS = 0, 1
+        lookup = (self, instring, loc, callPreParse, doActions)
+        with ParserElement.packrat_cache_lock:
+            cache = ParserElement.packrat_cache
+            value = cache.get(lookup)
+            if value is cache.not_in_cache:
+                ParserElement.packrat_cache_stats[MISS] += 1
+                try:
+                    value = self._parseNoCache(instring, loc, doActions, callPreParse)
+                except ParseBaseException as pe:
+                    # cache a copy of the exception, without the traceback
+                    cache.set(lookup, pe.__class__(*pe.args))
+                    raise
+                else:
+                    cache.set(lookup, (value[0], value[1].copy()))
+                    return value
+            else:
+                ParserElement.packrat_cache_stats[HIT] += 1
+                if isinstance(value, Exception):
+                    raise value
+                return (value[0], value[1].copy())
+
+    _parse = _parseNoCache
+
+    @staticmethod
+    def resetCache():
+        ParserElement.packrat_cache.clear()
+        ParserElement.packrat_cache_stats[:] = [0] * len(ParserElement.packrat_cache_stats)
+
+    _packratEnabled = False
+    @staticmethod
+    def enablePackrat(cache_size_limit=128):
+        """Enables "packrat" parsing, which adds memoizing to the parsing logic.
+           Repeated parse attempts at the same string location (which happens
+           often in many complex grammars) can immediately return a cached value,
+           instead of re-executing parsing/validating code.  Memoizing is done of
+           both valid results and parsing exceptions.
+           
+           Parameters:
+            - cache_size_limit - (default=C{128}) - if an integer value is provided
+              will limit the size of the packrat cache; if None is passed, then
+              the cache size will be unbounded; if 0 is passed, the cache will
+              be effectively disabled.
+            
+           This speedup may break existing programs that use parse actions that
+           have side-effects.  For this reason, packrat parsing is disabled when
+           you first import pyparsing.  To activate the packrat feature, your
+           program must call the class method C{ParserElement.enablePackrat()}.  If
+           your program uses C{psyco} to "compile as you go", you must call
+           C{enablePackrat} before calling C{psyco.full()}.  If you do not do this,
+           Python will crash.  For best results, call C{enablePackrat()} immediately
+           after importing pyparsing.
+           
+           Example::
+               import pyparsing
+               pyparsing.ParserElement.enablePackrat()
+        """
+        if not ParserElement._packratEnabled:
+            ParserElement._packratEnabled = True
+            if cache_size_limit is None:
+                ParserElement.packrat_cache = ParserElement._UnboundedCache()
+            else:
+                ParserElement.packrat_cache = ParserElement._FifoCache(cache_size_limit)
+            ParserElement._parse = ParserElement._parseCache
+
+    def parseString( self, instring, parseAll=False ):
+        """
+        Execute the parse expression with the given string.
+        This is the main interface to the client code, once the complete
+        expression has been built.
+
+        If you want the grammar to require that the entire input string be
+        successfully parsed, then set C{parseAll} to True (equivalent to ending
+        the grammar with C{L{StringEnd()}}).
+
+        Note: C{parseString} implicitly calls C{expandtabs()} on the input string,
+        in order to report proper column numbers in parse actions.
+        If the input string contains tabs and
+        the grammar uses parse actions that use the C{loc} argument to index into the
+        string being parsed, you can ensure you have a consistent view of the input
+        string by:
+         - calling C{parseWithTabs} on your grammar before calling C{parseString}
+           (see L{I{parseWithTabs}<parseWithTabs>})
+         - define your parse action using the full C{(s,loc,toks)} signature, and
+           reference the input string using the parse action's C{s} argument
+         - explictly expand the tabs in your input string before calling
+           C{parseString}
+        
+        Example::
+            Word('a').parseString('aaaaabaaa')  # -> ['aaaaa']
+            Word('a').parseString('aaaaabaaa', parseAll=True)  # -> Exception: Expected end of text
+        """
+        ParserElement.resetCache()
+        if not self.streamlined:
+            self.streamline()
+            #~ self.saveAsList = True
+        for e in self.ignoreExprs:
+            e.streamline()
+        if not self.keepTabs:
+            instring = instring.expandtabs()
+        try:
+            loc, tokens = self._parse( instring, 0 )
+            if parseAll:
+                loc = self.preParse( instring, loc )
+                se = Empty() + StringEnd()
+                se._parse( instring, loc )
+        except ParseBaseException as exc:
+            if ParserElement.verbose_stacktrace:
+                raise
+            else:
+                # catch and re-raise exception from here, clears out pyparsing internal stack trace
+                raise exc
+        else:
+            return tokens
+
+    def scanString( self, instring, maxMatches=_MAX_INT, overlap=False ):
+        """
+        Scan the input string for expression matches.  Each match will return the
+        matching tokens, start location, and end location.  May be called with optional
+        C{maxMatches} argument, to clip scanning after 'n' matches are found.  If
+        C{overlap} is specified, then overlapping matches will be reported.
+
+        Note that the start and end locations are reported relative to the string
+        being parsed.  See L{I{parseString}<parseString>} for more information on parsing
+        strings with embedded tabs.
+
+        Example::
+            source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
+            print(source)
+            for tokens,start,end in Word(alphas).scanString(source):
+                print(' '*start + '^'*(end-start))
+                print(' '*start + tokens[0])
+        
+        prints::
+        
+            sldjf123lsdjjkf345sldkjf879lkjsfd987
+            ^^^^^
+            sldjf
+                    ^^^^^^^
+                    lsdjjkf
+                              ^^^^^^
+                              sldkjf
+                                       ^^^^^^
+                                       lkjsfd
+        """
+        if not self.streamlined:
+            self.streamline()
+        for e in self.ignoreExprs:
+            e.streamline()
+
+        if not self.keepTabs:
+            instring = _ustr(instring).expandtabs()
+        instrlen = len(instring)
+        loc = 0
+        preparseFn = self.preParse
+        parseFn = self._parse
+        ParserElement.resetCache()
+        matches = 0
+        try:
+            while loc <= instrlen and matches < maxMatches:
+                try:
+                    preloc = preparseFn( instring, loc )
+                    nextLoc,tokens = parseFn( instring, preloc, callPreParse=False )
+                except ParseException:
+                    loc = preloc+1
+                else:
+                    if nextLoc > loc:
+                        matches += 1
+                        yield tokens, preloc, nextLoc
+                        if overlap:
+                            nextloc = preparseFn( instring, loc )
+                            if nextloc > loc:
+                                loc = nextLoc
+                            else:
+                                loc += 1
+                        else:
+                            loc = nextLoc
+                    else:
+                        loc = preloc+1
+        except ParseBaseException as exc:
+            if ParserElement.verbose_stacktrace:
+                raise
+            else:
+                # catch and re-raise exception from here, clears out pyparsing internal stack trace
+                raise exc
+
+    def transformString( self, instring ):
+        """
+        Extension to C{L{scanString}}, to modify matching text with modified tokens that may
+        be returned from a parse action.  To use C{transformString}, define a grammar and
+        attach a parse action to it that modifies the returned token list.
+        Invoking C{transformString()} on a target string will then scan for matches,
+        and replace the matched text patterns according to the logic in the parse
+        action.  C{transformString()} returns the resulting transformed string.
+        
+        Example::
+            wd = Word(alphas)
+            wd.setParseAction(lambda toks: toks[0].title())
+            
+            print(wd.transformString("now is the winter of our discontent made glorious summer by this sun of york."))
+        Prints::
+            Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
+        """
+        out = []
+        lastE = 0
+        # force preservation of <TAB>s, to minimize unwanted transformation of string, and to
+        # keep string locs straight between transformString and scanString
+        self.keepTabs = True
+        try:
+            for t,s,e in self.scanString( instring ):
+                out.append( instring[lastE:s] )
+                if t:
+                    if isinstance(t,ParseResults):
+                        out += t.asList()
+                    elif isinstance(t,list):
+                        out += t
+                    else:
+                        out.append(t)
+                lastE = e
+            out.append(instring[lastE:])
+            out = [o for o in out if o]
+            return "".join(map(_ustr,_flatten(out)))
+        except ParseBaseException as exc:
+            if ParserElement.verbose_stacktrace:
+                raise
+            else:
+                # catch and re-raise exception from here, clears out pyparsing internal stack trace
+                raise exc
+
+    def searchString( self, instring, maxMatches=_MAX_INT ):
+        """
+        Another extension to C{L{scanString}}, simplifying the access to the tokens found
+        to match the given parse expression.  May be called with optional
+        C{maxMatches} argument, to clip searching after 'n' matches are found.
+        
+        Example::
+            # a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
+            cap_word = Word(alphas.upper(), alphas.lower())
+            
+            print(cap_word.searchString("More than Iron, more than Lead, more than Gold I need Electricity"))
+
+            # the sum() builtin can be used to merge results into a single ParseResults object
+            print(sum(cap_word.searchString("More than Iron, more than Lead, more than Gold I need Electricity")))
+        prints::
+            [['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
+            ['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
+        """
+        try:
+            return ParseResults([ t for t,s,e in self.scanString( instring, maxMatches ) ])
+        except ParseBaseException as exc:
+            if ParserElement.verbose_stacktrace:
+                raise
+            else:
+                # catch and re-raise exception from here, clears out pyparsing internal stack trace
+                raise exc
+
+    def split(self, instring, maxsplit=_MAX_INT, includeSeparators=False):
+        """
+        Generator method to split a string using the given expression as a separator.
+        May be called with optional C{maxsplit} argument, to limit the number of splits;
+        and the optional C{includeSeparators} argument (default=C{False}), if the separating
+        matching text should be included in the split results.
+        
+        Example::        
+            punc = oneOf(list(".,;:/-!?"))
+            print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
+        prints::
+            ['This', ' this', '', ' this sentence', ' is badly punctuated', '']
+        """
+        splits = 0
+        last = 0
+        for t,s,e in self.scanString(instring, maxMatches=maxsplit):
+            yield instring[last:s]
+            if includeSeparators:
+                yield t[0]
+            last = e
+        yield instring[last:]
+
+    def __add__(self, other ):
+        """
+        Implementation of + operator - returns C{L{And}}. Adding strings to a ParserElement
+        converts them to L{Literal}s by default.
+        
+        Example::
+            greet = Word(alphas) + "," + Word(alphas) + "!"
+            hello = "Hello, World!"
+            print (hello, "->", greet.parseString(hello))
+        Prints::
+            Hello, World! -> ['Hello', ',', 'World', '!']
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return And( [ self, other ] )
+
+    def __radd__(self, other ):
+        """
+        Implementation of + operator when left operand is not a C{L{ParserElement}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return other + self
+
+    def __sub__(self, other):
+        """
+        Implementation of - operator, returns C{L{And}} with error stop
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return self + And._ErrorStop() + other
+
+    def __rsub__(self, other ):
+        """
+        Implementation of - operator when left operand is not a C{L{ParserElement}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return other - self
+
+    def __mul__(self,other):
+        """
+        Implementation of * operator, allows use of C{expr * 3} in place of
+        C{expr + expr + expr}.  Expressions may also me multiplied by a 2-integer
+        tuple, similar to C{{min,max}} multipliers in regular expressions.  Tuples
+        may also include C{None} as in:
+         - C{expr*(n,None)} or C{expr*(n,)} is equivalent
+              to C{expr*n + L{ZeroOrMore}(expr)}
+              (read as "at least n instances of C{expr}")
+         - C{expr*(None,n)} is equivalent to C{expr*(0,n)}
+              (read as "0 to n instances of C{expr}")
+         - C{expr*(None,None)} is equivalent to C{L{ZeroOrMore}(expr)}
+         - C{expr*(1,None)} is equivalent to C{L{OneOrMore}(expr)}
+
+        Note that C{expr*(None,n)} does not raise an exception if
+        more than n exprs exist in the input stream; that is,
+        C{expr*(None,n)} does not enforce a maximum number of expr
+        occurrences.  If this behavior is desired, then write
+        C{expr*(None,n) + ~expr}
+        """
+        if isinstance(other,int):
+            minElements, optElements = other,0
+        elif isinstance(other,tuple):
+            other = (other + (None, None))[:2]
+            if other[0] is None:
+                other = (0, other[1])
+            if isinstance(other[0],int) and other[1] is None:
+                if other[0] == 0:
+                    return ZeroOrMore(self)
+                if other[0] == 1:
+                    return OneOrMore(self)
+                else:
+                    return self*other[0] + ZeroOrMore(self)
+            elif isinstance(other[0],int) and isinstance(other[1],int):
+                minElements, optElements = other
+                optElements -= minElements
+            else:
+                raise TypeError("cannot multiply 'ParserElement' and ('%s','%s') objects", type(other[0]),type(other[1]))
+        else:
+            raise TypeError("cannot multiply 'ParserElement' and '%s' objects", type(other))
+
+        if minElements < 0:
+            raise ValueError("cannot multiply ParserElement by negative value")
+        if optElements < 0:
+            raise ValueError("second tuple value must be greater or equal to first tuple value")
+        if minElements == optElements == 0:
+            raise ValueError("cannot multiply ParserElement by 0 or (0,0)")
+
+        if (optElements):
+            def makeOptionalList(n):
+                if n>1:
+                    return Optional(self + makeOptionalList(n-1))
+                else:
+                    return Optional(self)
+            if minElements:
+                if minElements == 1:
+                    ret = self + makeOptionalList(optElements)
+                else:
+                    ret = And([self]*minElements) + makeOptionalList(optElements)
+            else:
+                ret = makeOptionalList(optElements)
+        else:
+            if minElements == 1:
+                ret = self
+            else:
+                ret = And([self]*minElements)
+        return ret
+
+    def __rmul__(self, other):
+        return self.__mul__(other)
+
+    def __or__(self, other ):
+        """
+        Implementation of | operator - returns C{L{MatchFirst}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return MatchFirst( [ self, other ] )
+
+    def __ror__(self, other ):
+        """
+        Implementation of | operator when left operand is not a C{L{ParserElement}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return other | self
+
+    def __xor__(self, other ):
+        """
+        Implementation of ^ operator - returns C{L{Or}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return Or( [ self, other ] )
+
+    def __rxor__(self, other ):
+        """
+        Implementation of ^ operator when left operand is not a C{L{ParserElement}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return other ^ self
+
+    def __and__(self, other ):
+        """
+        Implementation of & operator - returns C{L{Each}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return Each( [ self, other ] )
+
+    def __rand__(self, other ):
+        """
+        Implementation of & operator when left operand is not a C{L{ParserElement}}
+        """
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        if not isinstance( other, ParserElement ):
+            warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
+                    SyntaxWarning, stacklevel=2)
+            return None
+        return other & self
+
+    def __invert__( self ):
+        """
+        Implementation of ~ operator - returns C{L{NotAny}}
+        """
+        return NotAny( self )
+
+    def __call__(self, name=None):
+        """
+        Shortcut for C{L{setResultsName}}, with C{listAllMatches=False}.
+        
+        If C{name} is given with a trailing C{'*'} character, then C{listAllMatches} will be
+        passed as C{True}.
+           
+        If C{name} is omitted, same as calling C{L{copy}}.
+
+        Example::
+            # these are equivalent
+            userdata = Word(alphas).setResultsName("name") + Word(nums+"-").setResultsName("socsecno")
+            userdata = Word(alphas)("name") + Word(nums+"-")("socsecno")             
+        """
+        if name is not None:
+            return self.setResultsName(name)
+        else:
+            return self.copy()
+
+    def suppress( self ):
+        """
+        Suppresses the output of this C{ParserElement}; useful to keep punctuation from
+        cluttering up returned output.
+        """
+        return Suppress( self )
+
+    def leaveWhitespace( self ):
+        """
+        Disables the skipping of whitespace before matching the characters in the
+        C{ParserElement}'s defined pattern.  This is normally only used internally by
+        the pyparsing module, but may be needed in some whitespace-sensitive grammars.
+        """
+        self.skipWhitespace = False
+        return self
+
+    def setWhitespaceChars( self, chars ):
+        """
+        Overrides the default whitespace chars
+        """
+        self.skipWhitespace = True
+        self.whiteChars = chars
+        self.copyDefaultWhiteChars = False
+        return self
+
+    def parseWithTabs( self ):
+        """
+        Overrides default behavior to expand C{<TAB>}s to spaces before parsing the input string.
+        Must be called before C{parseString} when the input grammar contains elements that
+        match C{<TAB>} characters.
+        """
+        self.keepTabs = True
+        return self
+
+    def ignore( self, other ):
+        """
+        Define expression to be ignored (e.g., comments) while doing pattern
+        matching; may be called repeatedly, to define multiple comment or other
+        ignorable patterns.
+        
+        Example::
+            patt = OneOrMore(Word(alphas))
+            patt.parseString('ablaj /* comment */ lskjd') # -> ['ablaj']
+            
+            patt.ignore(cStyleComment)
+            patt.parseString('ablaj /* comment */ lskjd') # -> ['ablaj', 'lskjd']
+        """
+        if isinstance(other, basestring):
+            other = Suppress(other)
+
+        if isinstance( other, Suppress ):
+            if other not in self.ignoreExprs:
+                self.ignoreExprs.append(other)
+        else:
+            self.ignoreExprs.append( Suppress( other.copy() ) )
+        return self
+
+    def setDebugActions( self, startAction, successAction, exceptionAction ):
+        """
+        Enable display of debugging messages while doing pattern matching.
+        """
+        self.debugActions = (startAction or _defaultStartDebugAction,
+                             successAction or _defaultSuccessDebugAction,
+                             exceptionAction or _defaultExceptionDebugAction)
+        self.debug = True
+        return self
+
+    def setDebug( self, flag=True ):
+        """
+        Enable display of debugging messages while doing pattern matching.
+        Set C{flag} to True to enable, False to disable.
+
+        Example::
+            wd = Word(alphas).setName("alphaword")
+            integer = Word(nums).setName("numword")
+            term = wd | integer
+            
+            # turn on debugging for wd
+            wd.setDebug()
+
+            OneOrMore(term).parseString("abc 123 xyz 890")
+        
+        prints::
+            Match alphaword at loc 0(1,1)
+            Matched alphaword -> ['abc']
+            Match alphaword at loc 3(1,4)
+            Exception raised:Expected alphaword (at char 4), (line:1, col:5)
+            Match alphaword at loc 7(1,8)
+            Matched alphaword -> ['xyz']
+            Match alphaword at loc 11(1,12)
+            Exception raised:Expected alphaword (at char 12), (line:1, col:13)
+            Match alphaword at loc 15(1,16)
+            Exception raised:Expected alphaword (at char 15), (line:1, col:16)
+
+        The output shown is that produced by the default debug actions - custom debug actions can be
+        specified using L{setDebugActions}. Prior to attempting
+        to match the C{wd} expression, the debugging message C{"Match <exprname> at loc <n>(<line>,<col>)"}
+        is shown. Then if the parse succeeds, a C{"Matched"} message is shown, or an C{"Exception raised"}
+        message is shown. Also note the use of L{setName} to assign a human-readable name to the expression,
+        which makes debugging and exception messages easier to understand - for instance, the default
+        name created for the C{Word} expression without calling C{setName} is C{"W:(ABCD...)"}.
+        """
+        if flag:
+            self.setDebugActions( _defaultStartDebugAction, _defaultSuccessDebugAction, _defaultExceptionDebugAction )
+        else:
+            self.debug = False
+        return self
+
+    def __str__( self ):
+        return self.name
+
+    def __repr__( self ):
+        return _ustr(self)
+
+    def streamline( self ):
+        self.streamlined = True
+        self.strRepr = None
+        return self
+
+    def checkRecursion( self, parseElementList ):
+        pass
+
+    def validate( self, validateTrace=[] ):
+        """
+        Check defined expressions for valid structure, check for infinite recursive definitions.
+        """
+        self.checkRecursion( [] )
+
+    def parseFile( self, file_or_filename, parseAll=False ):
+        """
+        Execute the parse expression on the given file or filename.
+        If a filename is specified (instead of a file object),
+        the entire file is opened, read, and closed before parsing.
+        """
+        try:
+            file_contents = file_or_filename.read()
+        except AttributeError:
+            with open(file_or_filename, "r") as f:
+                file_contents = f.read()
+        try:
+            return self.parseString(file_contents, parseAll)
+        except ParseBaseException as exc:
+            if ParserElement.verbose_stacktrace:
+                raise
+            else:
+                # catch and re-raise exception from here, clears out pyparsing internal stack trace
+                raise exc
+
+    def __eq__(self,other):
+        if isinstance(other, ParserElement):
+            return self is other or vars(self) == vars(other)
+        elif isinstance(other, basestring):
+            return self.matches(other)
+        else:
+            return super(ParserElement,self)==other
+
+    def __ne__(self,other):
+        return not (self == other)
+
+    def __hash__(self):
+        return hash(id(self))
+
+    def __req__(self,other):
+        return self == other
+
+    def __rne__(self,other):
+        return not (self == other)
+
+    def matches(self, testString, parseAll=True):
+        """
+        Method for quick testing of a parser against a test string. Good for simple 
+        inline microtests of sub expressions while building up larger parser.
+           
+        Parameters:
+         - testString - to test against this expression for a match
+         - parseAll - (default=C{True}) - flag to pass to C{L{parseString}} when running tests
+            
+        Example::
+            expr = Word(nums)
+            assert expr.matches("100")
+        """
+        try:
+            self.parseString(_ustr(testString), parseAll=parseAll)
+            return True
+        except ParseBaseException:
+            return False
+                
+    def runTests(self, tests, parseAll=True, comment='#', fullDump=True, printResults=True, failureTests=False):
+        """
+        Execute the parse expression on a series of test strings, showing each
+        test, the parsed results or where the parse failed. Quick and easy way to
+        run a parse expression against a list of sample strings.
+           
+        Parameters:
+         - tests - a list of separate test strings, or a multiline string of test strings
+         - parseAll - (default=C{True}) - flag to pass to C{L{parseString}} when running tests           
+         - comment - (default=C{'#'}) - expression for indicating embedded comments in the test 
+              string; pass None to disable comment filtering
+         - fullDump - (default=C{True}) - dump results as list followed by results names in nested outline;
+              if False, only dump nested list
+         - printResults - (default=C{True}) prints test output to stdout
+         - failureTests - (default=C{False}) indicates if these tests are expected to fail parsing
+
+        Returns: a (success, results) tuple, where success indicates that all tests succeeded
+        (or failed if C{failureTests} is True), and the results contain a list of lines of each 
+        test's output
+        
+        Example::
+            number_expr = pyparsing_common.number.copy()
+
+            result = number_expr.runTests('''
+                # unsigned integer
+                100
+                # negative integer
+                -100
+                # float with scientific notation
+                6.02e23
+                # integer with scientific notation
+                1e-12
+                ''')
+            print("Success" if result[0] else "Failed!")
+
+            result = number_expr.runTests('''
+                # stray character
+                100Z
+                # missing leading digit before '.'
+                -.100
+                # too many '.'
+                3.14.159
+                ''', failureTests=True)
+            print("Success" if result[0] else "Failed!")
+        prints::
+            # unsigned integer
+            100
+            [100]
+
+            # negative integer
+            -100
+            [-100]
+
+            # float with scientific notation
+            6.02e23
+            [6.02e+23]
+
+            # integer with scientific notation
+            1e-12
+            [1e-12]
+
+            Success
+            
+            # stray character
+            100Z
+               ^
+            FAIL: Expected end of text (at char 3), (line:1, col:4)
+
+            # missing leading digit before '.'
+            -.100
+            ^
+            FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
+
+            # too many '.'
+            3.14.159
+                ^
+            FAIL: Expected end of text (at char 4), (line:1, col:5)
+
+            Success
+
+        Each test string must be on a single line. If you want to test a string that spans multiple
+        lines, create a test like this::
+
+            expr.runTest(r"this is a test\\n of strings that spans \\n 3 lines")
+        
+        (Note that this is a raw string literal, you must include the leading 'r'.)
+        """
+        if isinstance(tests, basestring):
+            tests = list(map(str.strip, tests.rstrip().splitlines()))
+        if isinstance(comment, basestring):
+            comment = Literal(comment)
+        allResults = []
+        comments = []
+        success = True
+        for t in tests:
+            if comment is not None and comment.matches(t, False) or comments and not t:
+                comments.append(t)
+                continue
+            if not t:
+                continue
+            out = ['\n'.join(comments), t]
+            comments = []
+            try:
+                t = t.replace(r'\n','\n')
+                result = self.parseString(t, parseAll=parseAll)
+                out.append(result.dump(full=fullDump))
+                success = success and not failureTests
+            except ParseBaseException as pe:
+                fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
+                if '\n' in t:
+                    out.append(line(pe.loc, t))
+                    out.append(' '*(col(pe.loc,t)-1) + '^' + fatal)
+                else:
+                    out.append(' '*pe.loc + '^' + fatal)
+                out.append("FAIL: " + str(pe))
+                success = success and failureTests
+                result = pe
+            except Exception as exc:
+                out.append("FAIL-EXCEPTION: " + str(exc))
+                success = success and failureTests
+                result = exc
+
+            if printResults:
+                if fullDump:
+                    out.append('')
+                print('\n'.join(out))
+
+            allResults.append((t, result))
+        
+        return success, allResults
+
+        
+class Token(ParserElement):
+    """
+    Abstract C{ParserElement} subclass, for defining atomic matching patterns.
+    """
+    def __init__( self ):
+        super(Token,self).__init__( savelist=False )
+
+
+class Empty(Token):
+    """
+    An empty token, will always match.
+    """
+    def __init__( self ):
+        super(Empty,self).__init__()
+        self.name = "Empty"
+        self.mayReturnEmpty = True
+        self.mayIndexError = False
+
+
+class NoMatch(Token):
+    """
+    A token that will never match.
+    """
+    def __init__( self ):
+        super(NoMatch,self).__init__()
+        self.name = "NoMatch"
+        self.mayReturnEmpty = True
+        self.mayIndexError = False
+        self.errmsg = "Unmatchable token"
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        raise ParseException(instring, loc, self.errmsg, self)
+
+
+class Literal(Token):
+    """
+    Token to exactly match a specified string.
+    
+    Example::
+        Literal('blah').parseString('blah')  # -> ['blah']
+        Literal('blah').parseString('blahfooblah')  # -> ['blah']
+        Literal('blah').parseString('bla')  # -> Exception: Expected "blah"
+    
+    For case-insensitive matching, use L{CaselessLiteral}.
+    
+    For keyword matching (force word break before and after the matched string),
+    use L{Keyword} or L{CaselessKeyword}.
+    """
+    def __init__( self, matchString ):
+        super(Literal,self).__init__()
+        self.match = matchString
+        self.matchLen = len(matchString)
+        try:
+            self.firstMatchChar = matchString[0]
+        except IndexError:
+            warnings.warn("null string passed to Literal; use Empty() instead",
+                            SyntaxWarning, stacklevel=2)
+            self.__class__ = Empty
+        self.name = '"%s"' % _ustr(self.match)
+        self.errmsg = "Expected " + self.name
+        self.mayReturnEmpty = False
+        self.mayIndexError = False
+
+    # Performance tuning: this routine gets called a *lot*
+    # if this is a single character match string  and the first character matches,
+    # short-circuit as quickly as possible, and avoid calling startswith
+    #~ @profile
+    def parseImpl( self, instring, loc, doActions=True ):
+        if (instring[loc] == self.firstMatchChar and
+            (self.matchLen==1 or instring.startswith(self.match,loc)) ):
+            return loc+self.matchLen, self.match
+        raise ParseException(instring, loc, self.errmsg, self)
+_L = Literal
+ParserElement._literalStringClass = Literal
+
+class Keyword(Token):
+    """
+    Token to exactly match a specified string as a keyword, that is, it must be
+    immediately followed by a non-keyword character.  Compare with C{L{Literal}}:
+     - C{Literal("if")} will match the leading C{'if'} in C{'ifAndOnlyIf'}.
+     - C{Keyword("if")} will not; it will only match the leading C{'if'} in C{'if x=1'}, or C{'if(y==2)'}
+    Accepts two optional constructor arguments in addition to the keyword string:
+     - C{identChars} is a string of characters that would be valid identifier characters,
+          defaulting to all alphanumerics + "_" and "$"
+     - C{caseless} allows case-insensitive matching, default is C{False}.
+       
+    Example::
+        Keyword("start").parseString("start")  # -> ['start']
+        Keyword("start").parseString("starting")  # -> Exception
+
+    For case-insensitive matching, use L{CaselessKeyword}.
+    """
+    DEFAULT_KEYWORD_CHARS = alphanums+"_$"
+
+    def __init__( self, matchString, identChars=None, caseless=False ):
+        super(Keyword,self).__init__()
+        if identChars is None:
+            identChars = Keyword.DEFAULT_KEYWORD_CHARS
+        self.match = matchString
+        self.matchLen = len(matchString)
+        try:
+            self.firstMatchChar = matchString[0]
+        except IndexError:
+            warnings.warn("null string passed to Keyword; use Empty() instead",
+                            SyntaxWarning, stacklevel=2)
+        self.name = '"%s"' % self.match
+        self.errmsg = "Expected " + self.name
+        self.mayReturnEmpty = False
+        self.mayIndexError = False
+        self.caseless = caseless
+        if caseless:
+            self.caselessmatch = matchString.upper()
+            identChars = identChars.upper()
+        self.identChars = set(identChars)
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if self.caseless:
+            if ( (instring[ loc:loc+self.matchLen ].upper() == self.caselessmatch) and
+                 (loc >= len(instring)-self.matchLen or instring[loc+self.matchLen].upper() not in self.identChars) and
+                 (loc == 0 or instring[loc-1].upper() not in self.identChars) ):
+                return loc+self.matchLen, self.match
+        else:
+            if (instring[loc] == self.firstMatchChar and
+                (self.matchLen==1 or instring.startswith(self.match,loc)) and
+                (loc >= len(instring)-self.matchLen or instring[loc+self.matchLen] not in self.identChars) and
+                (loc == 0 or instring[loc-1] not in self.identChars) ):
+                return loc+self.matchLen, self.match
+        raise ParseException(instring, loc, self.errmsg, self)
+
+    def copy(self):
+        c = super(Keyword,self).copy()
+        c.identChars = Keyword.DEFAULT_KEYWORD_CHARS
+        return c
+
+    @staticmethod
+    def setDefaultKeywordChars( chars ):
+        """Overrides the default Keyword chars
+        """
+        Keyword.DEFAULT_KEYWORD_CHARS = chars
+
+class CaselessLiteral(Literal):
+    """
+    Token to match a specified string, ignoring case of letters.
+    Note: the matched results will always be in the case of the given
+    match string, NOT the case of the input text.
+
+    Example::
+        OneOrMore(CaselessLiteral("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD', 'CMD']
+        
+    (Contrast with example for L{CaselessKeyword}.)
+    """
+    def __init__( self, matchString ):
+        super(CaselessLiteral,self).__init__( matchString.upper() )
+        # Preserve the defining literal.
+        self.returnString = matchString
+        self.name = "'%s'" % self.returnString
+        self.errmsg = "Expected " + self.name
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if instring[ loc:loc+self.matchLen ].upper() == self.match:
+            return loc+self.matchLen, self.returnString
+        raise ParseException(instring, loc, self.errmsg, self)
+
+class CaselessKeyword(Keyword):
+    """
+    Caseless version of L{Keyword}.
+
+    Example::
+        OneOrMore(CaselessKeyword("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD']
+        
+    (Contrast with example for L{CaselessLiteral}.)
+    """
+    def __init__( self, matchString, identChars=None ):
+        super(CaselessKeyword,self).__init__( matchString, identChars, caseless=True )
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if ( (instring[ loc:loc+self.matchLen ].upper() == self.caselessmatch) and
+             (loc >= len(instring)-self.matchLen or instring[loc+self.matchLen].upper() not in self.identChars) ):
+            return loc+self.matchLen, self.match
+        raise ParseException(instring, loc, self.errmsg, self)
+
+class CloseMatch(Token):
+    """
+    A variation on L{Literal} which matches "close" matches, that is, 
+    strings with at most 'n' mismatching characters. C{CloseMatch} takes parameters:
+     - C{match_string} - string to be matched
+     - C{maxMismatches} - (C{default=1}) maximum number of mismatches allowed to count as a match
+    
+    The results from a successful parse will contain the matched text from the input string and the following named results:
+     - C{mismatches} - a list of the positions within the match_string where mismatches were found
+     - C{original} - the original match_string used to compare against the input string
+    
+    If C{mismatches} is an empty list, then the match was an exact match.
+    
+    Example::
+        patt = CloseMatch("ATCATCGAATGGA")
+        patt.parseString("ATCATCGAAXGGA") # -> (['ATCATCGAAXGGA'], {'mismatches': [[9]], 'original': ['ATCATCGAATGGA']})
+        patt.parseString("ATCAXCGAAXGGA") # -> Exception: Expected 'ATCATCGAATGGA' (with up to 1 mismatches) (at char 0), (line:1, col:1)
+
+        # exact match
+        patt.parseString("ATCATCGAATGGA") # -> (['ATCATCGAATGGA'], {'mismatches': [[]], 'original': ['ATCATCGAATGGA']})
+
+        # close match allowing up to 2 mismatches
+        patt = CloseMatch("ATCATCGAATGGA", maxMismatches=2)
+        patt.parseString("ATCAXCGAAXGGA") # -> (['ATCAXCGAAXGGA'], {'mismatches': [[4, 9]], 'original': ['ATCATCGAATGGA']})
+    """
+    def __init__(self, match_string, maxMismatches=1):
+        super(CloseMatch,self).__init__()
+        self.name = match_string
+        self.match_string = match_string
+        self.maxMismatches = maxMismatches
+        self.errmsg = "Expected %r (with up to %d mismatches)" % (self.match_string, self.maxMismatches)
+        self.mayIndexError = False
+        self.mayReturnEmpty = False
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        start = loc
+        instrlen = len(instring)
+        maxloc = start + len(self.match_string)
+
+        if maxloc <= instrlen:
+            match_string = self.match_string
+            match_stringloc = 0
+            mismatches = []
+            maxMismatches = self.maxMismatches
+
+            for match_stringloc,s_m in enumerate(zip(instring[loc:maxloc], self.match_string)):
+                src,mat = s_m
+                if src != mat:
+                    mismatches.append(match_stringloc)
+                    if len(mismatches) > maxMismatches:
+                        break
+            else:
+                loc = match_stringloc + 1
+                results = ParseResults([instring[start:loc]])
+                results['original'] = self.match_string
+                results['mismatches'] = mismatches
+                return loc, results
+
+        raise ParseException(instring, loc, self.errmsg, self)
+
+
+class Word(Token):
+    """
+    Token for matching words composed of allowed character sets.
+    Defined with string containing all allowed initial characters,
+    an optional string containing allowed body characters (if omitted,
+    defaults to the initial character set), and an optional minimum,
+    maximum, and/or exact length.  The default value for C{min} is 1 (a
+    minimum value < 1 is not valid); the default values for C{max} and C{exact}
+    are 0, meaning no maximum or exact length restriction. An optional
+    C{excludeChars} parameter can list characters that might be found in 
+    the input C{bodyChars} string; useful to define a word of all printables
+    except for one or two characters, for instance.
+    
+    L{srange} is useful for defining custom character set strings for defining 
+    C{Word} expressions, using range notation from regular expression character sets.
+    
+    A common mistake is to use C{Word} to match a specific literal string, as in 
+    C{Word("Address")}. Remember that C{Word} uses the string argument to define
+    I{sets} of matchable characters. This expression would match "Add", "AAA",
+    "dAred", or any other word made up of the characters 'A', 'd', 'r', 'e', and 's'.
+    To match an exact literal string, use L{Literal} or L{Keyword}.
+
+    pyparsing includes helper strings for building Words:
+     - L{alphas}
+     - L{nums}
+     - L{alphanums}
+     - L{hexnums}
+     - L{alphas8bit} (alphabetic characters in ASCII range 128-255 - accented, tilded, umlauted, etc.)
+     - L{punc8bit} (non-alphabetic characters in ASCII range 128-255 - currency, symbols, superscripts, diacriticals, etc.)
+     - L{printables} (any non-whitespace character)
+
+    Example::
+        # a word composed of digits
+        integer = Word(nums) # equivalent to Word("0123456789") or Word(srange("0-9"))
+        
+        # a word with a leading capital, and zero or more lowercase
+        capital_word = Word(alphas.upper(), alphas.lower())
+
+        # hostnames are alphanumeric, with leading alpha, and '-'
+        hostname = Word(alphas, alphanums+'-')
+        
+        # roman numeral (not a strict parser, accepts invalid mix of characters)
+        roman = Word("IVXLCDM")
+        
+        # any string of non-whitespace characters, except for ','
+        csv_value = Word(printables, excludeChars=",")
+    """
+    def __init__( self, initChars, bodyChars=None, min=1, max=0, exact=0, asKeyword=False, excludeChars=None ):
+        super(Word,self).__init__()
+        if excludeChars:
+            initChars = ''.join(c for c in initChars if c not in excludeChars)
+            if bodyChars:
+                bodyChars = ''.join(c for c in bodyChars if c not in excludeChars)
+        self.initCharsOrig = initChars
+        self.initChars = set(initChars)
+        if bodyChars :
+            self.bodyCharsOrig = bodyChars
+            self.bodyChars = set(bodyChars)
+        else:
+            self.bodyCharsOrig = initChars
+            self.bodyChars = set(initChars)
+
+        self.maxSpecified = max > 0
+
+        if min < 1:
+            raise ValueError("cannot specify a minimum length < 1; use Optional(Word()) if zero-length word is permitted")
+
+        self.minLen = min
+
+        if max > 0:
+            self.maxLen = max
+        else:
+            self.maxLen = _MAX_INT
+
+        if exact > 0:
+            self.maxLen = exact
+            self.minLen = exact
+
+        self.name = _ustr(self)
+        self.errmsg = "Expected " + self.name
+        self.mayIndexError = False
+        self.asKeyword = asKeyword
+
+        if ' ' not in self.initCharsOrig+self.bodyCharsOrig and (min==1 and max==0 and exact==0):
+            if self.bodyCharsOrig == self.initCharsOrig:
+                self.reString = "[%s]+" % _escapeRegexRangeChars(self.initCharsOrig)
+            elif len(self.initCharsOrig) == 1:
+                self.reString = "%s[%s]*" % \
+                                      (re.escape(self.initCharsOrig),
+                                      _escapeRegexRangeChars(self.bodyCharsOrig),)
+            else:
+                self.reString = "[%s][%s]*" % \
+                                      (_escapeRegexRangeChars(self.initCharsOrig),
+                                      _escapeRegexRangeChars(self.bodyCharsOrig),)
+            if self.asKeyword:
+                self.reString = r"\b"+self.reString+r"\b"
+            try:
+                self.re = re.compile( self.reString )
+            except Exception:
+                self.re = None
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if self.re:
+            result = self.re.match(instring,loc)
+            if not result:
+                raise ParseException(instring, loc, self.errmsg, self)
+
+            loc = result.end()
+            return loc, result.group()
+
+        if not(instring[ loc ] in self.initChars):
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        start = loc
+        loc += 1
+        instrlen = len(instring)
+        bodychars = self.bodyChars
+        maxloc = start + self.maxLen
+        maxloc = min( maxloc, instrlen )
+        while loc < maxloc and instring[loc] in bodychars:
+            loc += 1
+
+        throwException = False
+        if loc - start < self.minLen:
+            throwException = True
+        if self.maxSpecified and loc < instrlen and instring[loc] in bodychars:
+            throwException = True
+        if self.asKeyword:
+            if (start>0 and instring[start-1] in bodychars) or (loc<instrlen and instring[loc] in bodychars):
+                throwException = True
+
+        if throwException:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        return loc, instring[start:loc]
+
+    def __str__( self ):
+        try:
+            return super(Word,self).__str__()
+        except Exception:
+            pass
+
+
+        if self.strRepr is None:
+
+            def charsAsStr(s):
+                if len(s)>4:
+                    return s[:4]+"..."
+                else:
+                    return s
+
+            if ( self.initCharsOrig != self.bodyCharsOrig ):
+                self.strRepr = "W:(%s,%s)" % ( charsAsStr(self.initCharsOrig), charsAsStr(self.bodyCharsOrig) )
+            else:
+                self.strRepr = "W:(%s)" % charsAsStr(self.initCharsOrig)
+
+        return self.strRepr
+
+
+class Regex(Token):
+    r"""
+    Token for matching strings that match a given regular expression.
+    Defined with string specifying the regular expression in a form recognized by the inbuilt Python re module.
+    If the given regex contains named groups (defined using C{(?P<name>...)}), these will be preserved as 
+    named parse results.
+
+    Example::
+        realnum = Regex(r"[+-]?\d+\.\d*")
+        date = Regex(r'(?P<year>\d{4})-(?P<month>\d\d?)-(?P<day>\d\d?)')
+        # ref: http://stackoverflow.com/questions/267399/how-do-you-match-only-valid-roman-numerals-with-a-regular-expression
+        roman = Regex(r"M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})")
+    """
+    compiledREtype = type(re.compile("[A-Z]"))
+    def __init__( self, pattern, flags=0):
+        """The parameters C{pattern} and C{flags} are passed to the C{re.compile()} function as-is. See the Python C{re} module for an explanation of the acceptable patterns and flags."""
+        super(Regex,self).__init__()
+
+        if isinstance(pattern, basestring):
+            if not pattern:
+                warnings.warn("null string passed to Regex; use Empty() instead",
+                        SyntaxWarning, stacklevel=2)
+
+            self.pattern = pattern
+            self.flags = flags
+
+            try:
+                self.re = re.compile(self.pattern, self.flags)
+                self.reString = self.pattern
+            except sre_constants.error:
+                warnings.warn("invalid pattern (%s) passed to Regex" % pattern,
+                    SyntaxWarning, stacklevel=2)
+                raise
+
+        elif isinstance(pattern, Regex.compiledREtype):
+            self.re = pattern
+            self.pattern = \
+            self.reString = str(pattern)
+            self.flags = flags
+            
+        else:
+            raise ValueError("Regex may only be constructed with a string or a compiled RE object")
+
+        self.name = _ustr(self)
+        self.errmsg = "Expected " + self.name
+        self.mayIndexError = False
+        self.mayReturnEmpty = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        result = self.re.match(instring,loc)
+        if not result:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        loc = result.end()
+        d = result.groupdict()
+        ret = ParseResults(result.group())
+        if d:
+            for k in d:
+                ret[k] = d[k]
+        return loc,ret
+
+    def __str__( self ):
+        try:
+            return super(Regex,self).__str__()
+        except Exception:
+            pass
+
+        if self.strRepr is None:
+            self.strRepr = "Re:(%s)" % repr(self.pattern)
+
+        return self.strRepr
+
+
+class QuotedString(Token):
+    r"""
+    Token for matching strings that are delimited by quoting characters.
+    
+    Defined with the following parameters:
+        - quoteChar - string of one or more characters defining the quote delimiting string
+        - escChar - character to escape quotes, typically backslash (default=C{None})
+        - escQuote - special quote sequence to escape an embedded quote string (such as SQL's "" to escape an embedded ") (default=C{None})
+        - multiline - boolean indicating whether quotes can span multiple lines (default=C{False})
+        - unquoteResults - boolean indicating whether the matched text should be unquoted (default=C{True})
+        - endQuoteChar - string of one or more characters defining the end of the quote delimited string (default=C{None} => same as quoteChar)
+        - convertWhitespaceEscapes - convert escaped whitespace (C{'\t'}, C{'\n'}, etc.) to actual whitespace (default=C{True})
+
+    Example::
+        qs = QuotedString('"')
+        print(qs.searchString('lsjdf "This is the quote" sldjf'))
+        complex_qs = QuotedString('{{', endQuoteChar='}}')
+        print(complex_qs.searchString('lsjdf {{This is the "quote"}} sldjf'))
+        sql_qs = QuotedString('"', escQuote='""')
+        print(sql_qs.searchString('lsjdf "This is the quote with ""embedded"" quotes" sldjf'))
+    prints::
+        [['This is the quote']]
+        [['This is the "quote"']]
+        [['This is the quote with "embedded" quotes']]
+    """
+    def __init__( self, quoteChar, escChar=None, escQuote=None, multiline=False, unquoteResults=True, endQuoteChar=None, convertWhitespaceEscapes=True):
+        super(QuotedString,self).__init__()
+
+        # remove white space from quote chars - wont work anyway
+        quoteChar = quoteChar.strip()
+        if not quoteChar:
+            warnings.warn("quoteChar cannot be the empty string",SyntaxWarning,stacklevel=2)
+            raise SyntaxError()
+
+        if endQuoteChar is None:
+            endQuoteChar = quoteChar
+        else:
+            endQuoteChar = endQuoteChar.strip()
+            if not endQuoteChar:
+                warnings.warn("endQuoteChar cannot be the empty string",SyntaxWarning,stacklevel=2)
+                raise SyntaxError()
+
+        self.quoteChar = quoteChar
+        self.quoteCharLen = len(quoteChar)
+        self.firstQuoteChar = quoteChar[0]
+        self.endQuoteChar = endQuoteChar
+        self.endQuoteCharLen = len(endQuoteChar)
+        self.escChar = escChar
+        self.escQuote = escQuote
+        self.unquoteResults = unquoteResults
+        self.convertWhitespaceEscapes = convertWhitespaceEscapes
+
+        if multiline:
+            self.flags = re.MULTILINE | re.DOTALL
+            self.pattern = r'%s(?:[^%s%s]' % \
+                ( re.escape(self.quoteChar),
+                  _escapeRegexRangeChars(self.endQuoteChar[0]),
+                  (escChar is not None and _escapeRegexRangeChars(escChar) or '') )
+        else:
+            self.flags = 0
+            self.pattern = r'%s(?:[^%s\n\r%s]' % \
+                ( re.escape(self.quoteChar),
+                  _escapeRegexRangeChars(self.endQuoteChar[0]),
+                  (escChar is not None and _escapeRegexRangeChars(escChar) or '') )
+        if len(self.endQuoteChar) > 1:
+            self.pattern += (
+                '|(?:' + ')|(?:'.join("%s[^%s]" % (re.escape(self.endQuoteChar[:i]),
+                                               _escapeRegexRangeChars(self.endQuoteChar[i]))
+                                    for i in range(len(self.endQuoteChar)-1,0,-1)) + ')'
+                )
+        if escQuote:
+            self.pattern += (r'|(?:%s)' % re.escape(escQuote))
+        if escChar:
+            self.pattern += (r'|(?:%s.)' % re.escape(escChar))
+            self.escCharReplacePattern = re.escape(self.escChar)+"(.)"
+        self.pattern += (r')*%s' % re.escape(self.endQuoteChar))
+
+        try:
+            self.re = re.compile(self.pattern, self.flags)
+            self.reString = self.pattern
+        except sre_constants.error:
+            warnings.warn("invalid pattern (%s) passed to Regex" % self.pattern,
+                SyntaxWarning, stacklevel=2)
+            raise
+
+        self.name = _ustr(self)
+        self.errmsg = "Expected " + self.name
+        self.mayIndexError = False
+        self.mayReturnEmpty = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        result = instring[loc] == self.firstQuoteChar and self.re.match(instring,loc) or None
+        if not result:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        loc = result.end()
+        ret = result.group()
+
+        if self.unquoteResults:
+
+            # strip off quotes
+            ret = ret[self.quoteCharLen:-self.endQuoteCharLen]
+
+            if isinstance(ret,basestring):
+                # replace escaped whitespace
+                if '\\' in ret and self.convertWhitespaceEscapes:
+                    ws_map = {
+                        r'\t' : '\t',
+                        r'\n' : '\n',
+                        r'\f' : '\f',
+                        r'\r' : '\r',
+                    }
+                    for wslit,wschar in ws_map.items():
+                        ret = ret.replace(wslit, wschar)
+
+                # replace escaped characters
+                if self.escChar:
+                    ret = re.sub(self.escCharReplacePattern, r"\g<1>", ret)
+
+                # replace escaped quotes
+                if self.escQuote:
+                    ret = ret.replace(self.escQuote, self.endQuoteChar)
+
+        return loc, ret
+
+    def __str__( self ):
+        try:
+            return super(QuotedString,self).__str__()
+        except Exception:
+            pass
+
+        if self.strRepr is None:
+            self.strRepr = "quoted string, starting with %s ending with %s" % (self.quoteChar, self.endQuoteChar)
+
+        return self.strRepr
+
+
+class CharsNotIn(Token):
+    """
+    Token for matching words composed of characters I{not} in a given set (will
+    include whitespace in matched characters if not listed in the provided exclusion set - see example).
+    Defined with string containing all disallowed characters, and an optional
+    minimum, maximum, and/or exact length.  The default value for C{min} is 1 (a
+    minimum value < 1 is not valid); the default values for C{max} and C{exact}
+    are 0, meaning no maximum or exact length restriction.
+
+    Example::
+        # define a comma-separated-value as anything that is not a ','
+        csv_value = CharsNotIn(',')
+        print(delimitedList(csv_value).parseString("dkls,lsdkjf,s12 34,@!#,213"))
+    prints::
+        ['dkls', 'lsdkjf', 's12 34', '@!#', '213']
+    """
+    def __init__( self, notChars, min=1, max=0, exact=0 ):
+        super(CharsNotIn,self).__init__()
+        self.skipWhitespace = False
+        self.notChars = notChars
+
+        if min < 1:
+            raise ValueError("cannot specify a minimum length < 1; use Optional(CharsNotIn()) if zero-length char group is permitted")
+
+        self.minLen = min
+
+        if max > 0:
+            self.maxLen = max
+        else:
+            self.maxLen = _MAX_INT
+
+        if exact > 0:
+            self.maxLen = exact
+            self.minLen = exact
+
+        self.name = _ustr(self)
+        self.errmsg = "Expected " + self.name
+        self.mayReturnEmpty = ( self.minLen == 0 )
+        self.mayIndexError = False
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if instring[loc] in self.notChars:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        start = loc
+        loc += 1
+        notchars = self.notChars
+        maxlen = min( start+self.maxLen, len(instring) )
+        while loc < maxlen and \
+              (instring[loc] not in notchars):
+            loc += 1
+
+        if loc - start < self.minLen:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        return loc, instring[start:loc]
+
+    def __str__( self ):
+        try:
+            return super(CharsNotIn, self).__str__()
+        except Exception:
+            pass
+
+        if self.strRepr is None:
+            if len(self.notChars) > 4:
+                self.strRepr = "!W:(%s...)" % self.notChars[:4]
+            else:
+                self.strRepr = "!W:(%s)" % self.notChars
+
+        return self.strRepr
+
+class White(Token):
+    """
+    Special matching class for matching whitespace.  Normally, whitespace is ignored
+    by pyparsing grammars.  This class is included when some whitespace structures
+    are significant.  Define with a string containing the whitespace characters to be
+    matched; default is C{" \\t\\r\\n"}.  Also takes optional C{min}, C{max}, and C{exact} arguments,
+    as defined for the C{L{Word}} class.
+    """
+    whiteStrs = {
+        " " : "<SPC>",
+        "\t": "<TAB>",
+        "\n": "<LF>",
+        "\r": "<CR>",
+        "\f": "<FF>",
+        }
+    def __init__(self, ws=" \t\r\n", min=1, max=0, exact=0):
+        super(White,self).__init__()
+        self.matchWhite = ws
+        self.setWhitespaceChars( "".join(c for c in self.whiteChars if c not in self.matchWhite) )
+        #~ self.leaveWhitespace()
+        self.name = ("".join(White.whiteStrs[c] for c in self.matchWhite))
+        self.mayReturnEmpty = True
+        self.errmsg = "Expected " + self.name
+
+        self.minLen = min
+
+        if max > 0:
+            self.maxLen = max
+        else:
+            self.maxLen = _MAX_INT
+
+        if exact > 0:
+            self.maxLen = exact
+            self.minLen = exact
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if not(instring[ loc ] in self.matchWhite):
+            raise ParseException(instring, loc, self.errmsg, self)
+        start = loc
+        loc += 1
+        maxloc = start + self.maxLen
+        maxloc = min( maxloc, len(instring) )
+        while loc < maxloc and instring[loc] in self.matchWhite:
+            loc += 1
+
+        if loc - start < self.minLen:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        return loc, instring[start:loc]
+
+
+class _PositionToken(Token):
+    def __init__( self ):
+        super(_PositionToken,self).__init__()
+        self.name=self.__class__.__name__
+        self.mayReturnEmpty = True
+        self.mayIndexError = False
+
+class GoToColumn(_PositionToken):
+    """
+    Token to advance to a specific column of input text; useful for tabular report scraping.
+    """
+    def __init__( self, colno ):
+        super(GoToColumn,self).__init__()
+        self.col = colno
+
+    def preParse( self, instring, loc ):
+        if col(loc,instring) != self.col:
+            instrlen = len(instring)
+            if self.ignoreExprs:
+                loc = self._skipIgnorables( instring, loc )
+            while loc < instrlen and instring[loc].isspace() and col( loc, instring ) != self.col :
+                loc += 1
+        return loc
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        thiscol = col( loc, instring )
+        if thiscol > self.col:
+            raise ParseException( instring, loc, "Text not in expected column", self )
+        newloc = loc + self.col - thiscol
+        ret = instring[ loc: newloc ]
+        return newloc, ret
+
+
+class LineStart(_PositionToken):
+    """
+    Matches if current position is at the beginning of a line within the parse string
+    
+    Example::
+    
+        test = '''\
+        AAA this line
+        AAA and this line
+          AAA but not this one
+        B AAA and definitely not this one
+        '''
+
+        for t in (LineStart() + 'AAA' + restOfLine).searchString(test):
+            print(t)
+    
+    Prints::
+        ['AAA', ' this line']
+        ['AAA', ' and this line']    
+
+    """
+    def __init__( self ):
+        super(LineStart,self).__init__()
+        self.errmsg = "Expected start of line"
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if col(loc, instring) == 1:
+            return loc, []
+        raise ParseException(instring, loc, self.errmsg, self)
+
+class LineEnd(_PositionToken):
+    """
+    Matches if current position is at the end of a line within the parse string
+    """
+    def __init__( self ):
+        super(LineEnd,self).__init__()
+        self.setWhitespaceChars( ParserElement.DEFAULT_WHITE_CHARS.replace("\n","") )
+        self.errmsg = "Expected end of line"
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if loc<len(instring):
+            if instring[loc] == "\n":
+                return loc+1, "\n"
+            else:
+                raise ParseException(instring, loc, self.errmsg, self)
+        elif loc == len(instring):
+            return loc+1, []
+        else:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+class StringStart(_PositionToken):
+    """
+    Matches if current position is at the beginning of the parse string
+    """
+    def __init__( self ):
+        super(StringStart,self).__init__()
+        self.errmsg = "Expected start of text"
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if loc != 0:
+            # see if entire string up to here is just whitespace and ignoreables
+            if loc != self.preParse( instring, 0 ):
+                raise ParseException(instring, loc, self.errmsg, self)
+        return loc, []
+
+class StringEnd(_PositionToken):
+    """
+    Matches if current position is at the end of the parse string
+    """
+    def __init__( self ):
+        super(StringEnd,self).__init__()
+        self.errmsg = "Expected end of text"
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if loc < len(instring):
+            raise ParseException(instring, loc, self.errmsg, self)
+        elif loc == len(instring):
+            return loc+1, []
+        elif loc > len(instring):
+            return loc, []
+        else:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+class WordStart(_PositionToken):
+    """
+    Matches if the current position is at the beginning of a Word, and
+    is not preceded by any character in a given set of C{wordChars}
+    (default=C{printables}). To emulate the C{\b} behavior of regular expressions,
+    use C{WordStart(alphanums)}. C{WordStart} will also match at the beginning of
+    the string being parsed, or at the beginning of a line.
+    """
+    def __init__(self, wordChars = printables):
+        super(WordStart,self).__init__()
+        self.wordChars = set(wordChars)
+        self.errmsg = "Not at the start of a word"
+
+    def parseImpl(self, instring, loc, doActions=True ):
+        if loc != 0:
+            if (instring[loc-1] in self.wordChars or
+                instring[loc] not in self.wordChars):
+                raise ParseException(instring, loc, self.errmsg, self)
+        return loc, []
+
+class WordEnd(_PositionToken):
+    """
+    Matches if the current position is at the end of a Word, and
+    is not followed by any character in a given set of C{wordChars}
+    (default=C{printables}). To emulate the C{\b} behavior of regular expressions,
+    use C{WordEnd(alphanums)}. C{WordEnd} will also match at the end of
+    the string being parsed, or at the end of a line.
+    """
+    def __init__(self, wordChars = printables):
+        super(WordEnd,self).__init__()
+        self.wordChars = set(wordChars)
+        self.skipWhitespace = False
+        self.errmsg = "Not at the end of a word"
+
+    def parseImpl(self, instring, loc, doActions=True ):
+        instrlen = len(instring)
+        if instrlen>0 and loc<instrlen:
+            if (instring[loc] in self.wordChars or
+                instring[loc-1] not in self.wordChars):
+                raise ParseException(instring, loc, self.errmsg, self)
+        return loc, []
+
+
+class ParseExpression(ParserElement):
+    """
+    Abstract subclass of ParserElement, for combining and post-processing parsed tokens.
+    """
+    def __init__( self, exprs, savelist = False ):
+        super(ParseExpression,self).__init__(savelist)
+        if isinstance( exprs, _generatorType ):
+            exprs = list(exprs)
+
+        if isinstance( exprs, basestring ):
+            self.exprs = [ ParserElement._literalStringClass( exprs ) ]
+        elif isinstance( exprs, Iterable ):
+            exprs = list(exprs)
+            # if sequence of strings provided, wrap with Literal
+            if all(isinstance(expr, basestring) for expr in exprs):
+                exprs = map(ParserElement._literalStringClass, exprs)
+            self.exprs = list(exprs)
+        else:
+            try:
+                self.exprs = list( exprs )
+            except TypeError:
+                self.exprs = [ exprs ]
+        self.callPreparse = False
+
+    def __getitem__( self, i ):
+        return self.exprs[i]
+
+    def append( self, other ):
+        self.exprs.append( other )
+        self.strRepr = None
+        return self
+
+    def leaveWhitespace( self ):
+        """Extends C{leaveWhitespace} defined in base class, and also invokes C{leaveWhitespace} on
+           all contained expressions."""
+        self.skipWhitespace = False
+        self.exprs = [ e.copy() for e in self.exprs ]
+        for e in self.exprs:
+            e.leaveWhitespace()
+        return self
+
+    def ignore( self, other ):
+        if isinstance( other, Suppress ):
+            if other not in self.ignoreExprs:
+                super( ParseExpression, self).ignore( other )
+                for e in self.exprs:
+                    e.ignore( self.ignoreExprs[-1] )
+        else:
+            super( ParseExpression, self).ignore( other )
+            for e in self.exprs:
+                e.ignore( self.ignoreExprs[-1] )
+        return self
+
+    def __str__( self ):
+        try:
+            return super(ParseExpression,self).__str__()
+        except Exception:
+            pass
+
+        if self.strRepr is None:
+            self.strRepr = "%s:(%s)" % ( self.__class__.__name__, _ustr(self.exprs) )
+        return self.strRepr
+
+    def streamline( self ):
+        super(ParseExpression,self).streamline()
+
+        for e in self.exprs:
+            e.streamline()
+
+        # collapse nested And's of the form And( And( And( a,b), c), d) to And( a,b,c,d )
+        # but only if there are no parse actions or resultsNames on the nested And's
+        # (likewise for Or's and MatchFirst's)
+        if ( len(self.exprs) == 2 ):
+            other = self.exprs[0]
+            if ( isinstance( other, self.__class__ ) and
+                  not(other.parseAction) and
+                  other.resultsName is None and
+                  not other.debug ):
+                self.exprs = other.exprs[:] + [ self.exprs[1] ]
+                self.strRepr = None
+                self.mayReturnEmpty |= other.mayReturnEmpty
+                self.mayIndexError  |= other.mayIndexError
+
+            other = self.exprs[-1]
+            if ( isinstance( other, self.__class__ ) and
+                  not(other.parseAction) and
+                  other.resultsName is None and
+                  not other.debug ):
+                self.exprs = self.exprs[:-1] + other.exprs[:]
+                self.strRepr = None
+                self.mayReturnEmpty |= other.mayReturnEmpty
+                self.mayIndexError  |= other.mayIndexError
+
+        self.errmsg = "Expected " + _ustr(self)
+        
+        return self
+
+    def setResultsName( self, name, listAllMatches=False ):
+        ret = super(ParseExpression,self).setResultsName(name,listAllMatches)
+        return ret
+
+    def validate( self, validateTrace=[] ):
+        tmp = validateTrace[:]+[self]
+        for e in self.exprs:
+            e.validate(tmp)
+        self.checkRecursion( [] )
+        
+    def copy(self):
+        ret = super(ParseExpression,self).copy()
+        ret.exprs = [e.copy() for e in self.exprs]
+        return ret
+
+class And(ParseExpression):
+    """
+    Requires all given C{ParseExpression}s to be found in the given order.
+    Expressions may be separated by whitespace.
+    May be constructed using the C{'+'} operator.
+    May also be constructed using the C{'-'} operator, which will suppress backtracking.
+
+    Example::
+        integer = Word(nums)
+        name_expr = OneOrMore(Word(alphas))
+
+        expr = And([integer("id"),name_expr("name"),integer("age")])
+        # more easily written as:
+        expr = integer("id") + name_expr("name") + integer("age")
+    """
+
+    class _ErrorStop(Empty):
+        def __init__(self, *args, **kwargs):
+            super(And._ErrorStop,self).__init__(*args, **kwargs)
+            self.name = '-'
+            self.leaveWhitespace()
+
+    def __init__( self, exprs, savelist = True ):
+        super(And,self).__init__(exprs, savelist)
+        self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
+        self.setWhitespaceChars( self.exprs[0].whiteChars )
+        self.skipWhitespace = self.exprs[0].skipWhitespace
+        self.callPreparse = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        # pass False as last arg to _parse for first element, since we already
+        # pre-parsed the string as part of our And pre-parsing
+        loc, resultlist = self.exprs[0]._parse( instring, loc, doActions, callPreParse=False )
+        errorStop = False
+        for e in self.exprs[1:]:
+            if isinstance(e, And._ErrorStop):
+                errorStop = True
+                continue
+            if errorStop:
+                try:
+                    loc, exprtokens = e._parse( instring, loc, doActions )
+                except ParseSyntaxException:
+                    raise
+                except ParseBaseException as pe:
+                    pe.__traceback__ = None
+                    raise ParseSyntaxException._from_exception(pe)
+                except IndexError:
+                    raise ParseSyntaxException(instring, len(instring), self.errmsg, self)
+            else:
+                loc, exprtokens = e._parse( instring, loc, doActions )
+            if exprtokens or exprtokens.haskeys():
+                resultlist += exprtokens
+        return loc, resultlist
+
+    def __iadd__(self, other ):
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        return self.append( other ) #And( [ self, other ] )
+
+    def checkRecursion( self, parseElementList ):
+        subRecCheckList = parseElementList[:] + [ self ]
+        for e in self.exprs:
+            e.checkRecursion( subRecCheckList )
+            if not e.mayReturnEmpty:
+                break
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "{" + " ".join(_ustr(e) for e in self.exprs) + "}"
+
+        return self.strRepr
+
+
+class Or(ParseExpression):
+    """
+    Requires that at least one C{ParseExpression} is found.
+    If two expressions match, the expression that matches the longest string will be used.
+    May be constructed using the C{'^'} operator.
+
+    Example::
+        # construct Or using '^' operator
+        
+        number = Word(nums) ^ Combine(Word(nums) + '.' + Word(nums))
+        print(number.searchString("123 3.1416 789"))
+    prints::
+        [['123'], ['3.1416'], ['789']]
+    """
+    def __init__( self, exprs, savelist = False ):
+        super(Or,self).__init__(exprs, savelist)
+        if self.exprs:
+            self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
+        else:
+            self.mayReturnEmpty = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        maxExcLoc = -1
+        maxException = None
+        matches = []
+        for e in self.exprs:
+            try:
+                loc2 = e.tryParse( instring, loc )
+            except ParseException as err:
+                err.__traceback__ = None
+                if err.loc > maxExcLoc:
+                    maxException = err
+                    maxExcLoc = err.loc
+            except IndexError:
+                if len(instring) > maxExcLoc:
+                    maxException = ParseException(instring,len(instring),e.errmsg,self)
+                    maxExcLoc = len(instring)
+            else:
+                # save match among all matches, to retry longest to shortest
+                matches.append((loc2, e))
+
+        if matches:
+            matches.sort(key=lambda x: -x[0])
+            for _,e in matches:
+                try:
+                    return e._parse( instring, loc, doActions )
+                except ParseException as err:
+                    err.__traceback__ = None
+                    if err.loc > maxExcLoc:
+                        maxException = err
+                        maxExcLoc = err.loc
+
+        if maxException is not None:
+            maxException.msg = self.errmsg
+            raise maxException
+        else:
+            raise ParseException(instring, loc, "no defined alternatives to match", self)
+
+
+    def __ixor__(self, other ):
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        return self.append( other ) #Or( [ self, other ] )
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "{" + " ^ ".join(_ustr(e) for e in self.exprs) + "}"
+
+        return self.strRepr
+
+    def checkRecursion( self, parseElementList ):
+        subRecCheckList = parseElementList[:] + [ self ]
+        for e in self.exprs:
+            e.checkRecursion( subRecCheckList )
+
+
+class MatchFirst(ParseExpression):
+    """
+    Requires that at least one C{ParseExpression} is found.
+    If two expressions match, the first one listed is the one that will match.
+    May be constructed using the C{'|'} operator.
+
+    Example::
+        # construct MatchFirst using '|' operator
+        
+        # watch the order of expressions to match
+        number = Word(nums) | Combine(Word(nums) + '.' + Word(nums))
+        print(number.searchString("123 3.1416 789")) #  Fail! -> [['123'], ['3'], ['1416'], ['789']]
+
+        # put more selective expression first
+        number = Combine(Word(nums) + '.' + Word(nums)) | Word(nums)
+        print(number.searchString("123 3.1416 789")) #  Better -> [['123'], ['3.1416'], ['789']]
+    """
+    def __init__( self, exprs, savelist = False ):
+        super(MatchFirst,self).__init__(exprs, savelist)
+        if self.exprs:
+            self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
+        else:
+            self.mayReturnEmpty = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        maxExcLoc = -1
+        maxException = None
+        for e in self.exprs:
+            try:
+                ret = e._parse( instring, loc, doActions )
+                return ret
+            except ParseException as err:
+                if err.loc > maxExcLoc:
+                    maxException = err
+                    maxExcLoc = err.loc
+            except IndexError:
+                if len(instring) > maxExcLoc:
+                    maxException = ParseException(instring,len(instring),e.errmsg,self)
+                    maxExcLoc = len(instring)
+
+        # only got here if no expression matched, raise exception for match that made it the furthest
+        else:
+            if maxException is not None:
+                maxException.msg = self.errmsg
+                raise maxException
+            else:
+                raise ParseException(instring, loc, "no defined alternatives to match", self)
+
+    def __ior__(self, other ):
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass( other )
+        return self.append( other ) #MatchFirst( [ self, other ] )
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "{" + " | ".join(_ustr(e) for e in self.exprs) + "}"
+
+        return self.strRepr
+
+    def checkRecursion( self, parseElementList ):
+        subRecCheckList = parseElementList[:] + [ self ]
+        for e in self.exprs:
+            e.checkRecursion( subRecCheckList )
+
+
+class Each(ParseExpression):
+    """
+    Requires all given C{ParseExpression}s to be found, but in any order.
+    Expressions may be separated by whitespace.
+    May be constructed using the C{'&'} operator.
+
+    Example::
+        color = oneOf("RED ORANGE YELLOW GREEN BLUE PURPLE BLACK WHITE BROWN")
+        shape_type = oneOf("SQUARE CIRCLE TRIANGLE STAR HEXAGON OCTAGON")
+        integer = Word(nums)
+        shape_attr = "shape:" + shape_type("shape")
+        posn_attr = "posn:" + Group(integer("x") + ',' + integer("y"))("posn")
+        color_attr = "color:" + color("color")
+        size_attr = "size:" + integer("size")
+
+        # use Each (using operator '&') to accept attributes in any order 
+        # (shape and posn are required, color and size are optional)
+        shape_spec = shape_attr & posn_attr & Optional(color_attr) & Optional(size_attr)
+
+        shape_spec.runTests('''
+            shape: SQUARE color: BLACK posn: 100, 120
+            shape: CIRCLE size: 50 color: BLUE posn: 50,80
+            color:GREEN size:20 shape:TRIANGLE posn:20,40
+            '''
+            )
+    prints::
+        shape: SQUARE color: BLACK posn: 100, 120
+        ['shape:', 'SQUARE', 'color:', 'BLACK', 'posn:', ['100', ',', '120']]
+        - color: BLACK
+        - posn: ['100', ',', '120']
+          - x: 100
+          - y: 120
+        - shape: SQUARE
+
+
+        shape: CIRCLE size: 50 color: BLUE posn: 50,80
+        ['shape:', 'CIRCLE', 'size:', '50', 'color:', 'BLUE', 'posn:', ['50', ',', '80']]
+        - color: BLUE
+        - posn: ['50', ',', '80']
+          - x: 50
+          - y: 80
+        - shape: CIRCLE
+        - size: 50
+
+
+        color: GREEN size: 20 shape: TRIANGLE posn: 20,40
+        ['color:', 'GREEN', 'size:', '20', 'shape:', 'TRIANGLE', 'posn:', ['20', ',', '40']]
+        - color: GREEN
+        - posn: ['20', ',', '40']
+          - x: 20
+          - y: 40
+        - shape: TRIANGLE
+        - size: 20
+    """
+    def __init__( self, exprs, savelist = True ):
+        super(Each,self).__init__(exprs, savelist)
+        self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
+        self.skipWhitespace = True
+        self.initExprGroups = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if self.initExprGroups:
+            self.opt1map = dict((id(e.expr),e) for e in self.exprs if isinstance(e,Optional))
+            opt1 = [ e.expr for e in self.exprs if isinstance(e,Optional) ]
+            opt2 = [ e for e in self.exprs if e.mayReturnEmpty and not isinstance(e,Optional)]
+            self.optionals = opt1 + opt2
+            self.multioptionals = [ e.expr for e in self.exprs if isinstance(e,ZeroOrMore) ]
+            self.multirequired = [ e.expr for e in self.exprs if isinstance(e,OneOrMore) ]
+            self.required = [ e for e in self.exprs if not isinstance(e,(Optional,ZeroOrMore,OneOrMore)) ]
+            self.required += self.multirequired
+            self.initExprGroups = False
+        tmpLoc = loc
+        tmpReqd = self.required[:]
+        tmpOpt  = self.optionals[:]
+        matchOrder = []
+
+        keepMatching = True
+        while keepMatching:
+            tmpExprs = tmpReqd + tmpOpt + self.multioptionals + self.multirequired
+            failed = []
+            for e in tmpExprs:
+                try:
+                    tmpLoc = e.tryParse( instring, tmpLoc )
+                except ParseException:
+                    failed.append(e)
+                else:
+                    matchOrder.append(self.opt1map.get(id(e),e))
+                    if e in tmpReqd:
+                        tmpReqd.remove(e)
+                    elif e in tmpOpt:
+                        tmpOpt.remove(e)
+            if len(failed) == len(tmpExprs):
+                keepMatching = False
+
+        if tmpReqd:
+            missing = ", ".join(_ustr(e) for e in tmpReqd)
+            raise ParseException(instring,loc,"Missing one or more required elements (%s)" % missing )
+
+        # add any unmatched Optionals, in case they have default values defined
+        matchOrder += [e for e in self.exprs if isinstance(e,Optional) and e.expr in tmpOpt]
+
+        resultlist = []
+        for e in matchOrder:
+            loc,results = e._parse(instring,loc,doActions)
+            resultlist.append(results)
+
+        finalResults = sum(resultlist, ParseResults([]))
+        return loc, finalResults
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "{" + " & ".join(_ustr(e) for e in self.exprs) + "}"
+
+        return self.strRepr
+
+    def checkRecursion( self, parseElementList ):
+        subRecCheckList = parseElementList[:] + [ self ]
+        for e in self.exprs:
+            e.checkRecursion( subRecCheckList )
+
+
+class ParseElementEnhance(ParserElement):
+    """
+    Abstract subclass of C{ParserElement}, for combining and post-processing parsed tokens.
+    """
+    def __init__( self, expr, savelist=False ):
+        super(ParseElementEnhance,self).__init__(savelist)
+        if isinstance( expr, basestring ):
+            if issubclass(ParserElement._literalStringClass, Token):
+                expr = ParserElement._literalStringClass(expr)
+            else:
+                expr = ParserElement._literalStringClass(Literal(expr))
+        self.expr = expr
+        self.strRepr = None
+        if expr is not None:
+            self.mayIndexError = expr.mayIndexError
+            self.mayReturnEmpty = expr.mayReturnEmpty
+            self.setWhitespaceChars( expr.whiteChars )
+            self.skipWhitespace = expr.skipWhitespace
+            self.saveAsList = expr.saveAsList
+            self.callPreparse = expr.callPreparse
+            self.ignoreExprs.extend(expr.ignoreExprs)
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if self.expr is not None:
+            return self.expr._parse( instring, loc, doActions, callPreParse=False )
+        else:
+            raise ParseException("",loc,self.errmsg,self)
+
+    def leaveWhitespace( self ):
+        self.skipWhitespace = False
+        self.expr = self.expr.copy()
+        if self.expr is not None:
+            self.expr.leaveWhitespace()
+        return self
+
+    def ignore( self, other ):
+        if isinstance( other, Suppress ):
+            if other not in self.ignoreExprs:
+                super( ParseElementEnhance, self).ignore( other )
+                if self.expr is not None:
+                    self.expr.ignore( self.ignoreExprs[-1] )
+        else:
+            super( ParseElementEnhance, self).ignore( other )
+            if self.expr is not None:
+                self.expr.ignore( self.ignoreExprs[-1] )
+        return self
+
+    def streamline( self ):
+        super(ParseElementEnhance,self).streamline()
+        if self.expr is not None:
+            self.expr.streamline()
+        return self
+
+    def checkRecursion( self, parseElementList ):
+        if self in parseElementList:
+            raise RecursiveGrammarException( parseElementList+[self] )
+        subRecCheckList = parseElementList[:] + [ self ]
+        if self.expr is not None:
+            self.expr.checkRecursion( subRecCheckList )
+
+    def validate( self, validateTrace=[] ):
+        tmp = validateTrace[:]+[self]
+        if self.expr is not None:
+            self.expr.validate(tmp)
+        self.checkRecursion( [] )
+
+    def __str__( self ):
+        try:
+            return super(ParseElementEnhance,self).__str__()
+        except Exception:
+            pass
+
+        if self.strRepr is None and self.expr is not None:
+            self.strRepr = "%s:(%s)" % ( self.__class__.__name__, _ustr(self.expr) )
+        return self.strRepr
+
+
+class FollowedBy(ParseElementEnhance):
+    """
+    Lookahead matching of the given parse expression.  C{FollowedBy}
+    does I{not} advance the parsing position within the input string, it only
+    verifies that the specified parse expression matches at the current
+    position.  C{FollowedBy} always returns a null token list.
+
+    Example::
+        # use FollowedBy to match a label only if it is followed by a ':'
+        data_word = Word(alphas)
+        label = data_word + FollowedBy(':')
+        attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
+        
+        OneOrMore(attr_expr).parseString("shape: SQUARE color: BLACK posn: upper left").pprint()
+    prints::
+        [['shape', 'SQUARE'], ['color', 'BLACK'], ['posn', 'upper left']]
+    """
+    def __init__( self, expr ):
+        super(FollowedBy,self).__init__(expr)
+        self.mayReturnEmpty = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        self.expr.tryParse( instring, loc )
+        return loc, []
+
+
+class NotAny(ParseElementEnhance):
+    """
+    Lookahead to disallow matching with the given parse expression.  C{NotAny}
+    does I{not} advance the parsing position within the input string, it only
+    verifies that the specified parse expression does I{not} match at the current
+    position.  Also, C{NotAny} does I{not} skip over leading whitespace. C{NotAny}
+    always returns a null token list.  May be constructed using the '~' operator.
+
+    Example::
+        
+    """
+    def __init__( self, expr ):
+        super(NotAny,self).__init__(expr)
+        #~ self.leaveWhitespace()
+        self.skipWhitespace = False  # do NOT use self.leaveWhitespace(), don't want to propagate to exprs
+        self.mayReturnEmpty = True
+        self.errmsg = "Found unwanted token, "+_ustr(self.expr)
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        if self.expr.canParseNext(instring, loc):
+            raise ParseException(instring, loc, self.errmsg, self)
+        return loc, []
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "~{" + _ustr(self.expr) + "}"
+
+        return self.strRepr
+
+class _MultipleMatch(ParseElementEnhance):
+    def __init__( self, expr, stopOn=None):
+        super(_MultipleMatch, self).__init__(expr)
+        self.saveAsList = True
+        ender = stopOn
+        if isinstance(ender, basestring):
+            ender = ParserElement._literalStringClass(ender)
+        self.not_ender = ~ender if ender is not None else None
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        self_expr_parse = self.expr._parse
+        self_skip_ignorables = self._skipIgnorables
+        check_ender = self.not_ender is not None
+        if check_ender:
+            try_not_ender = self.not_ender.tryParse
+        
+        # must be at least one (but first see if we are the stopOn sentinel;
+        # if so, fail)
+        if check_ender:
+            try_not_ender(instring, loc)
+        loc, tokens = self_expr_parse( instring, loc, doActions, callPreParse=False )
+        try:
+            hasIgnoreExprs = (not not self.ignoreExprs)
+            while 1:
+                if check_ender:
+                    try_not_ender(instring, loc)
+                if hasIgnoreExprs:
+                    preloc = self_skip_ignorables( instring, loc )
+                else:
+                    preloc = loc
+                loc, tmptokens = self_expr_parse( instring, preloc, doActions )
+                if tmptokens or tmptokens.haskeys():
+                    tokens += tmptokens
+        except (ParseException,IndexError):
+            pass
+
+        return loc, tokens
+        
+class OneOrMore(_MultipleMatch):
+    """
+    Repetition of one or more of the given expression.
+    
+    Parameters:
+     - expr - expression that must match one or more times
+     - stopOn - (default=C{None}) - expression for a terminating sentinel
+          (only required if the sentinel would ordinarily match the repetition 
+          expression)          
+
+    Example::
+        data_word = Word(alphas)
+        label = data_word + FollowedBy(':')
+        attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).setParseAction(' '.join))
+
+        text = "shape: SQUARE posn: upper left color: BLACK"
+        OneOrMore(attr_expr).parseString(text).pprint()  # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']]
+
+        # use stopOn attribute for OneOrMore to avoid reading label string as part of the data
+        attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
+        OneOrMore(attr_expr).parseString(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']]
+        
+        # could also be written as
+        (attr_expr * (1,)).parseString(text).pprint()
+    """
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "{" + _ustr(self.expr) + "}..."
+
+        return self.strRepr
+
+class ZeroOrMore(_MultipleMatch):
+    """
+    Optional repetition of zero or more of the given expression.
+    
+    Parameters:
+     - expr - expression that must match zero or more times
+     - stopOn - (default=C{None}) - expression for a terminating sentinel
+          (only required if the sentinel would ordinarily match the repetition 
+          expression)          
+
+    Example: similar to L{OneOrMore}
+    """
+    def __init__( self, expr, stopOn=None):
+        super(ZeroOrMore,self).__init__(expr, stopOn=stopOn)
+        self.mayReturnEmpty = True
+        
+    def parseImpl( self, instring, loc, doActions=True ):
+        try:
+            return super(ZeroOrMore, self).parseImpl(instring, loc, doActions)
+        except (ParseException,IndexError):
+            return loc, []
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "[" + _ustr(self.expr) + "]..."
+
+        return self.strRepr
+
+class _NullToken(object):
+    def __bool__(self):
+        return False
+    __nonzero__ = __bool__
+    def __str__(self):
+        return ""
+
+_optionalNotMatched = _NullToken()
+class Optional(ParseElementEnhance):
+    """
+    Optional matching of the given expression.
+
+    Parameters:
+     - expr - expression that must match zero or more times
+     - default (optional) - value to be returned if the optional expression is not found.
+
+    Example::
+        # US postal code can be a 5-digit zip, plus optional 4-digit qualifier
+        zip = Combine(Word(nums, exact=5) + Optional('-' + Word(nums, exact=4)))
+        zip.runTests('''
+            # traditional ZIP code
+            12345
+            
+            # ZIP+4 form
+            12101-0001
+            
+            # invalid ZIP
+            98765-
+            ''')
+    prints::
+        # traditional ZIP code
+        12345
+        ['12345']
+
+        # ZIP+4 form
+        12101-0001
+        ['12101-0001']
+
+        # invalid ZIP
+        98765-
+             ^
+        FAIL: Expected end of text (at char 5), (line:1, col:6)
+    """
+    def __init__( self, expr, default=_optionalNotMatched ):
+        super(Optional,self).__init__( expr, savelist=False )
+        self.saveAsList = self.expr.saveAsList
+        self.defaultValue = default
+        self.mayReturnEmpty = True
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        try:
+            loc, tokens = self.expr._parse( instring, loc, doActions, callPreParse=False )
+        except (ParseException,IndexError):
+            if self.defaultValue is not _optionalNotMatched:
+                if self.expr.resultsName:
+                    tokens = ParseResults([ self.defaultValue ])
+                    tokens[self.expr.resultsName] = self.defaultValue
+                else:
+                    tokens = [ self.defaultValue ]
+            else:
+                tokens = []
+        return loc, tokens
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+
+        if self.strRepr is None:
+            self.strRepr = "[" + _ustr(self.expr) + "]"
+
+        return self.strRepr
+
+class SkipTo(ParseElementEnhance):
+    """
+    Token for skipping over all undefined text until the matched expression is found.
+
+    Parameters:
+     - expr - target expression marking the end of the data to be skipped
+     - include - (default=C{False}) if True, the target expression is also parsed 
+          (the skipped text and target expression are returned as a 2-element list).
+     - ignore - (default=C{None}) used to define grammars (typically quoted strings and 
+          comments) that might contain false matches to the target expression
+     - failOn - (default=C{None}) define expressions that are not allowed to be 
+          included in the skipped test; if found before the target expression is found, 
+          the SkipTo is not a match
+
+    Example::
+        report = '''
+            Outstanding Issues Report - 1 Jan 2000
+
+               # | Severity | Description                               |  Days Open
+            -----+----------+-------------------------------------------+-----------
+             101 | Critical | Intermittent system crash                 |          6
+              94 | Cosmetic | Spelling error on Login ('log|n')         |         14
+              79 | Minor    | System slow when running too many reports |         47
+            '''
+        integer = Word(nums)
+        SEP = Suppress('|')
+        # use SkipTo to simply match everything up until the next SEP
+        # - ignore quoted strings, so that a '|' character inside a quoted string does not match
+        # - parse action will call token.strip() for each matched token, i.e., the description body
+        string_data = SkipTo(SEP, ignore=quotedString)
+        string_data.setParseAction(tokenMap(str.strip))
+        ticket_expr = (integer("issue_num") + SEP 
+                      + string_data("sev") + SEP 
+                      + string_data("desc") + SEP 
+                      + integer("days_open"))
+        
+        for tkt in ticket_expr.searchString(report):
+            print tkt.dump()
+    prints::
+        ['101', 'Critical', 'Intermittent system crash', '6']
+        - days_open: 6
+        - desc: Intermittent system crash
+        - issue_num: 101
+        - sev: Critical
+        ['94', 'Cosmetic', "Spelling error on Login ('log|n')", '14']
+        - days_open: 14
+        - desc: Spelling error on Login ('log|n')
+        - issue_num: 94
+        - sev: Cosmetic
+        ['79', 'Minor', 'System slow when running too many reports', '47']
+        - days_open: 47
+        - desc: System slow when running too many reports
+        - issue_num: 79
+        - sev: Minor
+    """
+    def __init__( self, other, include=False, ignore=None, failOn=None ):
+        super( SkipTo, self ).__init__( other )
+        self.ignoreExpr = ignore
+        self.mayReturnEmpty = True
+        self.mayIndexError = False
+        self.includeMatch = include
+        self.asList = False
+        if isinstance(failOn, basestring):
+            self.failOn = ParserElement._literalStringClass(failOn)
+        else:
+            self.failOn = failOn
+        self.errmsg = "No match found for "+_ustr(self.expr)
+
+    def parseImpl( self, instring, loc, doActions=True ):
+        startloc = loc
+        instrlen = len(instring)
+        expr = self.expr
+        expr_parse = self.expr._parse
+        self_failOn_canParseNext = self.failOn.canParseNext if self.failOn is not None else None
+        self_ignoreExpr_tryParse = self.ignoreExpr.tryParse if self.ignoreExpr is not None else None
+        
+        tmploc = loc
+        while tmploc <= instrlen:
+            if self_failOn_canParseNext is not None:
+                # break if failOn expression matches
+                if self_failOn_canParseNext(instring, tmploc):
+                    break
+                    
+            if self_ignoreExpr_tryParse is not None:
+                # advance past ignore expressions
+                while 1:
+                    try:
+                        tmploc = self_ignoreExpr_tryParse(instring, tmploc)
+                    except ParseBaseException:
+                        break
+            
+            try:
+                expr_parse(instring, tmploc, doActions=False, callPreParse=False)
+            except (ParseException, IndexError):
+                # no match, advance loc in string
+                tmploc += 1
+            else:
+                # matched skipto expr, done
+                break
+
+        else:
+            # ran off the end of the input string without matching skipto expr, fail
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        # build up return values
+        loc = tmploc
+        skiptext = instring[startloc:loc]
+        skipresult = ParseResults(skiptext)
+        
+        if self.includeMatch:
+            loc, mat = expr_parse(instring,loc,doActions,callPreParse=False)
+            skipresult += mat
+
+        return loc, skipresult
+
+class Forward(ParseElementEnhance):
+    """
+    Forward declaration of an expression to be defined later -
+    used for recursive grammars, such as algebraic infix notation.
+    When the expression is known, it is assigned to the C{Forward} variable using the '<<' operator.
+
+    Note: take care when assigning to C{Forward} not to overlook precedence of operators.
+    Specifically, '|' has a lower precedence than '<<', so that::
+        fwdExpr << a | b | c
+    will actually be evaluated as::
+        (fwdExpr << a) | b | c
+    thereby leaving b and c out as parseable alternatives.  It is recommended that you
+    explicitly group the values inserted into the C{Forward}::
+        fwdExpr << (a | b | c)
+    Converting to use the '<<=' operator instead will avoid this problem.
+
+    See L{ParseResults.pprint} for an example of a recursive parser created using
+    C{Forward}.
+    """
+    def __init__( self, other=None ):
+        super(Forward,self).__init__( other, savelist=False )
+
+    def __lshift__( self, other ):
+        if isinstance( other, basestring ):
+            other = ParserElement._literalStringClass(other)
+        self.expr = other
+        self.strRepr = None
+        self.mayIndexError = self.expr.mayIndexError
+        self.mayReturnEmpty = self.expr.mayReturnEmpty
+        self.setWhitespaceChars( self.expr.whiteChars )
+        self.skipWhitespace = self.expr.skipWhitespace
+        self.saveAsList = self.expr.saveAsList
+        self.ignoreExprs.extend(self.expr.ignoreExprs)
+        return self
+        
+    def __ilshift__(self, other):
+        return self << other
+    
+    def leaveWhitespace( self ):
+        self.skipWhitespace = False
+        return self
+
+    def streamline( self ):
+        if not self.streamlined:
+            self.streamlined = True
+            if self.expr is not None:
+                self.expr.streamline()
+        return self
+
+    def validate( self, validateTrace=[] ):
+        if self not in validateTrace:
+            tmp = validateTrace[:]+[self]
+            if self.expr is not None:
+                self.expr.validate(tmp)
+        self.checkRecursion([])
+
+    def __str__( self ):
+        if hasattr(self,"name"):
+            return self.name
+        return self.__class__.__name__ + ": ..."
+
+        # stubbed out for now - creates awful memory and perf issues
+        self._revertClass = self.__class__
+        self.__class__ = _ForwardNoRecurse
+        try:
+            if self.expr is not None:
+                retString = _ustr(self.expr)
+            else:
+                retString = "None"
+        finally:
+            self.__class__ = self._revertClass
+        return self.__class__.__name__ + ": " + retString
+
+    def copy(self):
+        if self.expr is not None:
+            return super(Forward,self).copy()
+        else:
+            ret = Forward()
+            ret <<= self
+            return ret
+
+class _ForwardNoRecurse(Forward):
+    def __str__( self ):
+        return "..."
+
+class TokenConverter(ParseElementEnhance):
+    """
+    Abstract subclass of C{ParseExpression}, for converting parsed results.
+    """
+    def __init__( self, expr, savelist=False ):
+        super(TokenConverter,self).__init__( expr )#, savelist )
+        self.saveAsList = False
+
+class Combine(TokenConverter):
+    """
+    Converter to concatenate all matching tokens to a single string.
+    By default, the matching patterns must also be contiguous in the input string;
+    this can be disabled by specifying C{'adjacent=False'} in the constructor.
+
+    Example::
+        real = Word(nums) + '.' + Word(nums)
+        print(real.parseString('3.1416')) # -> ['3', '.', '1416']
+        # will also erroneously match the following
+        print(real.parseString('3. 1416')) # -> ['3', '.', '1416']
+
+        real = Combine(Word(nums) + '.' + Word(nums))
+        print(real.parseString('3.1416')) # -> ['3.1416']
+        # no match when there are internal spaces
+        print(real.parseString('3. 1416')) # -> Exception: Expected W:(0123...)
+    """
+    def __init__( self, expr, joinString="", adjacent=True ):
+        super(Combine,self).__init__( expr )
+        # suppress whitespace-stripping in contained parse expressions, but re-enable it on the Combine itself
+        if adjacent:
+            self.leaveWhitespace()
+        self.adjacent = adjacent
+        self.skipWhitespace = True
+        self.joinString = joinString
+        self.callPreparse = True
+
+    def ignore( self, other ):
+        if self.adjacent:
+            ParserElement.ignore(self, other)
+        else:
+            super( Combine, self).ignore( other )
+        return self
+
+    def postParse( self, instring, loc, tokenlist ):
+        retToks = tokenlist.copy()
+        del retToks[:]
+        retToks += ParseResults([ "".join(tokenlist._asStringList(self.joinString)) ], modal=self.modalResults)
+
+        if self.resultsName and retToks.haskeys():
+            return [ retToks ]
+        else:
+            return retToks
+
+class Group(TokenConverter):
+    """
+    Converter to return the matched tokens as a list - useful for returning tokens of C{L{ZeroOrMore}} and C{L{OneOrMore}} expressions.
+
+    Example::
+        ident = Word(alphas)
+        num = Word(nums)
+        term = ident | num
+        func = ident + Optional(delimitedList(term))
+        print(func.parseString("fn a,b,100"))  # -> ['fn', 'a', 'b', '100']
+
+        func = ident + Group(Optional(delimitedList(term)))
+        print(func.parseString("fn a,b,100"))  # -> ['fn', ['a', 'b', '100']]
+    """
+    def __init__( self, expr ):
+        super(Group,self).__init__( expr )
+        self.saveAsList = True
+
+    def postParse( self, instring, loc, tokenlist ):
+        return [ tokenlist ]
+
+class Dict(TokenConverter):
+    """
+    Converter to return a repetitive expression as a list, but also as a dictionary.
+    Each element can also be referenced using the first token in the expression as its key.
+    Useful for tabular report scraping when the first column can be used as a item key.
+
+    Example::
+        data_word = Word(alphas)
+        label = data_word + FollowedBy(':')
+        attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).setParseAction(' '.join))
+
+        text = "shape: SQUARE posn: upper left color: light blue texture: burlap"
+        attr_expr = (label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
+        
+        # print attributes as plain groups
+        print(OneOrMore(attr_expr).parseString(text).dump())
+        
+        # instead of OneOrMore(expr), parse using Dict(OneOrMore(Group(expr))) - Dict will auto-assign names
+        result = Dict(OneOrMore(Group(attr_expr))).parseString(text)
+        print(result.dump())
+        
+        # access named fields as dict entries, or output as dict
+        print(result['shape'])        
+        print(result.asDict())
+    prints::
+        ['shape', 'SQUARE', 'posn', 'upper left', 'color', 'light blue', 'texture', 'burlap']
+
+        [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']]
+        - color: light blue
+        - posn: upper left
+        - shape: SQUARE
+        - texture: burlap
+        SQUARE
+        {'color': 'light blue', 'posn': 'upper left', 'texture': 'burlap', 'shape': 'SQUARE'}
+    See more examples at L{ParseResults} of accessing fields by results name.
+    """
+    def __init__( self, expr ):
+        super(Dict,self).__init__( expr )
+        self.saveAsList = True
+
+    def postParse( self, instring, loc, tokenlist ):
+        for i,tok in enumerate(tokenlist):
+            if len(tok) == 0:
+                continue
+            ikey = tok[0]
+            if isinstance(ikey,int):
+                ikey = _ustr(tok[0]).strip()
+            if len(tok)==1:
+                tokenlist[ikey] = _ParseResultsWithOffset("",i)
+            elif len(tok)==2 and not isinstance(tok[1],ParseResults):
+                tokenlist[ikey] = _ParseResultsWithOffset(tok[1],i)
+            else:
+                dictvalue = tok.copy() #ParseResults(i)
+                del dictvalue[0]
+                if len(dictvalue)!= 1 or (isinstance(dictvalue,ParseResults) and dictvalue.haskeys()):
+                    tokenlist[ikey] = _ParseResultsWithOffset(dictvalue,i)
+                else:
+                    tokenlist[ikey] = _ParseResultsWithOffset(dictvalue[0],i)
+
+        if self.resultsName:
+            return [ tokenlist ]
+        else:
+            return tokenlist
+
+
+class Suppress(TokenConverter):
+    """
+    Converter for ignoring the results of a parsed expression.
+
+    Example::
+        source = "a, b, c,d"
+        wd = Word(alphas)
+        wd_list1 = wd + ZeroOrMore(',' + wd)
+        print(wd_list1.parseString(source))
+
+        # often, delimiters that are useful during parsing are just in the
+        # way afterward - use Suppress to keep them out of the parsed output
+        wd_list2 = wd + ZeroOrMore(Suppress(',') + wd)
+        print(wd_list2.parseString(source))
+    prints::
+        ['a', ',', 'b', ',', 'c', ',', 'd']
+        ['a', 'b', 'c', 'd']
+    (See also L{delimitedList}.)
+    """
+    def postParse( self, instring, loc, tokenlist ):
+        return []
+
+    def suppress( self ):
+        return self
+
+
+class OnlyOnce(object):
+    """
+    Wrapper for parse actions, to ensure they are only called once.
+    """
+    def __init__(self, methodCall):
+        self.callable = _trim_arity(methodCall)
+        self.called = False
+    def __call__(self,s,l,t):
+        if not self.called:
+            results = self.callable(s,l,t)
+            self.called = True
+            return results
+        raise ParseException(s,l,"")
+    def reset(self):
+        self.called = False
+
+def traceParseAction(f):
+    """
+    Decorator for debugging parse actions. 
+    
+    When the parse action is called, this decorator will print C{">> entering I{method-name}(line:I{current_source_line}, I{parse_location}, I{matched_tokens})".}
+    When the parse action completes, the decorator will print C{"<<"} followed by the returned value, or any exception that the parse action raised.
+
+    Example::
+        wd = Word(alphas)
+
+        @traceParseAction
+        def remove_duplicate_chars(tokens):
+            return ''.join(sorted(set(''.join(tokens))))
+
+        wds = OneOrMore(wd).setParseAction(remove_duplicate_chars)
+        print(wds.parseString("slkdjs sld sldd sdlf sdljf"))
+    prints::
+        >>entering remove_duplicate_chars(line: 'slkdjs sld sldd sdlf sdljf', 0, (['slkdjs', 'sld', 'sldd', 'sdlf', 'sdljf'], {}))
+        <<leaving remove_duplicate_chars (ret: 'dfjkls')
+        ['dfjkls']
+    """
+    f = _trim_arity(f)
+    def z(*paArgs):
+        thisFunc = f.__name__
+        s,l,t = paArgs[-3:]
+        if len(paArgs)>3:
+            thisFunc = paArgs[0].__class__.__name__ + '.' + thisFunc
+        sys.stderr.write( ">>entering %s(line: '%s', %d, %r)\n" % (thisFunc,line(l,s),l,t) )
+        try:
+            ret = f(*paArgs)
+        except Exception as exc:
+            sys.stderr.write( "<<leaving %s (exception: %s)\n" % (thisFunc,exc) )
+            raise
+        sys.stderr.write( "<<leaving %s (ret: %r)\n" % (thisFunc,ret) )
+        return ret
+    try:
+        z.__name__ = f.__name__
+    except AttributeError:
+        pass
+    return z
+
+#
+# global helpers
+#
+def delimitedList( expr, delim=",", combine=False ):
+    """
+    Helper to define a delimited list of expressions - the delimiter defaults to ','.
+    By default, the list elements and delimiters can have intervening whitespace, and
+    comments, but this can be overridden by passing C{combine=True} in the constructor.
+    If C{combine} is set to C{True}, the matching tokens are returned as a single token
+    string, with the delimiters included; otherwise, the matching tokens are returned
+    as a list of tokens, with the delimiters suppressed.
+
+    Example::
+        delimitedList(Word(alphas)).parseString("aa,bb,cc") # -> ['aa', 'bb', 'cc']
+        delimitedList(Word(hexnums), delim=':', combine=True).parseString("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE']
+    """
+    dlName = _ustr(expr)+" ["+_ustr(delim)+" "+_ustr(expr)+"]..."
+    if combine:
+        return Combine( expr + ZeroOrMore( delim + expr ) ).setName(dlName)
+    else:
+        return ( expr + ZeroOrMore( Suppress( delim ) + expr ) ).setName(dlName)
+
+def countedArray( expr, intExpr=None ):
+    """
+    Helper to define a counted list of expressions.
+    This helper defines a pattern of the form::
+        integer expr expr expr...
+    where the leading integer tells how many expr expressions follow.
+    The matched tokens returns the array of expr tokens as a list - the leading count token is suppressed.
+    
+    If C{intExpr} is specified, it should be a pyparsing expression that produces an integer value.
+
+    Example::
+        countedArray(Word(alphas)).parseString('2 ab cd ef')  # -> ['ab', 'cd']
+
+        # in this parser, the leading integer value is given in binary,
+        # '10' indicating that 2 values are in the array
+        binaryConstant = Word('01').setParseAction(lambda t: int(t[0], 2))
+        countedArray(Word(alphas), intExpr=binaryConstant).parseString('10 ab cd ef')  # -> ['ab', 'cd']
+    """
+    arrayExpr = Forward()
+    def countFieldParseAction(s,l,t):
+        n = t[0]
+        arrayExpr << (n and Group(And([expr]*n)) or Group(empty))
+        return []
+    if intExpr is None:
+        intExpr = Word(nums).setParseAction(lambda t:int(t[0]))
+    else:
+        intExpr = intExpr.copy()
+    intExpr.setName("arrayLen")
+    intExpr.addParseAction(countFieldParseAction, callDuringTry=True)
+    return ( intExpr + arrayExpr ).setName('(len) ' + _ustr(expr) + '...')
+
+def _flatten(L):
+    ret = []
+    for i in L:
+        if isinstance(i,list):
+            ret.extend(_flatten(i))
+        else:
+            ret.append(i)
+    return ret
+
+def matchPreviousLiteral(expr):
+    """
+    Helper to define an expression that is indirectly defined from
+    the tokens matched in a previous expression, that is, it looks
+    for a 'repeat' of a previous expression.  For example::
+        first = Word(nums)
+        second = matchPreviousLiteral(first)
+        matchExpr = first + ":" + second
+    will match C{"1:1"}, but not C{"1:2"}.  Because this matches a
+    previous literal, will also match the leading C{"1:1"} in C{"1:10"}.
+    If this is not desired, use C{matchPreviousExpr}.
+    Do I{not} use with packrat parsing enabled.
+    """
+    rep = Forward()
+    def copyTokenToRepeater(s,l,t):
+        if t:
+            if len(t) == 1:
+                rep << t[0]
+            else:
+                # flatten t tokens
+                tflat = _flatten(t.asList())
+                rep << And(Literal(tt) for tt in tflat)
+        else:
+            rep << Empty()
+    expr.addParseAction(copyTokenToRepeater, callDuringTry=True)
+    rep.setName('(prev) ' + _ustr(expr))
+    return rep
+
+def matchPreviousExpr(expr):
+    """
+    Helper to define an expression that is indirectly defined from
+    the tokens matched in a previous expression, that is, it looks
+    for a 'repeat' of a previous expression.  For example::
+        first = Word(nums)
+        second = matchPreviousExpr(first)
+        matchExpr = first + ":" + second
+    will match C{"1:1"}, but not C{"1:2"}.  Because this matches by
+    expressions, will I{not} match the leading C{"1:1"} in C{"1:10"};
+    the expressions are evaluated first, and then compared, so
+    C{"1"} is compared with C{"10"}.
+    Do I{not} use with packrat parsing enabled.
+    """
+    rep = Forward()
+    e2 = expr.copy()
+    rep <<= e2
+    def copyTokenToRepeater(s,l,t):
+        matchTokens = _flatten(t.asList())
+        def mustMatchTheseTokens(s,l,t):
+            theseTokens = _flatten(t.asList())
+            if  theseTokens != matchTokens:
+                raise ParseException("",0,"")
+        rep.setParseAction( mustMatchTheseTokens, callDuringTry=True )
+    expr.addParseAction(copyTokenToRepeater, callDuringTry=True)
+    rep.setName('(prev) ' + _ustr(expr))
+    return rep
+
+def _escapeRegexRangeChars(s):
+    #~  escape these chars: ^-]
+    for c in r"\^-]":
+        s = s.replace(c,_bslash+c)
+    s = s.replace("\n",r"\n")
+    s = s.replace("\t",r"\t")
+    return _ustr(s)
+
+def oneOf( strs, caseless=False, useRegex=True ):
+    """
+    Helper to quickly define a set of alternative Literals, and makes sure to do
+    longest-first testing when there is a conflict, regardless of the input order,
+    but returns a C{L{MatchFirst}} for best performance.
+
+    Parameters:
+     - strs - a string of space-delimited literals, or a collection of string literals
+     - caseless - (default=C{False}) - treat all literals as caseless
+     - useRegex - (default=C{True}) - as an optimization, will generate a Regex
+          object; otherwise, will generate a C{MatchFirst} object (if C{caseless=True}, or
+          if creating a C{Regex} raises an exception)
+
+    Example::
+        comp_oper = oneOf("< = > <= >= !=")
+        var = Word(alphas)
+        number = Word(nums)
+        term = var | number
+        comparison_expr = term + comp_oper + term
+        print(comparison_expr.searchString("B = 12  AA=23 B<=AA AA>12"))
+    prints::
+        [['B', '=', '12'], ['AA', '=', '23'], ['B', '<=', 'AA'], ['AA', '>', '12']]
+    """
+    if caseless:
+        isequal = ( lambda a,b: a.upper() == b.upper() )
+        masks = ( lambda a,b: b.upper().startswith(a.upper()) )
+        parseElementClass = CaselessLiteral
+    else:
+        isequal = ( lambda a,b: a == b )
+        masks = ( lambda a,b: b.startswith(a) )
+        parseElementClass = Literal
+
+    symbols = []
+    if isinstance(strs,basestring):
+        symbols = strs.split()
+    elif isinstance(strs, Iterable):
+        symbols = list(strs)
+    else:
+        warnings.warn("Invalid argument to oneOf, expected string or iterable",
+                SyntaxWarning, stacklevel=2)
+    if not symbols:
+        return NoMatch()
+
+    i = 0
+    while i < len(symbols)-1:
+        cur = symbols[i]
+        for j,other in enumerate(symbols[i+1:]):
+            if ( isequal(other, cur) ):
+                del symbols[i+j+1]
+                break
+            elif ( masks(cur, other) ):
+                del symbols[i+j+1]
+                symbols.insert(i,other)
+                cur = other
+                break
+        else:
+            i += 1
+
+    if not caseless and useRegex:
+        #~ print (strs,"->", "|".join( [ _escapeRegexChars(sym) for sym in symbols] ))
+        try:
+            if len(symbols)==len("".join(symbols)):
+                return Regex( "[%s]" % "".join(_escapeRegexRangeChars(sym) for sym in symbols) ).setName(' | '.join(symbols))
+            else:
+                return Regex( "|".join(re.escape(sym) for sym in symbols) ).setName(' | '.join(symbols))
+        except Exception:
+            warnings.warn("Exception creating Regex for oneOf, building MatchFirst",
+                    SyntaxWarning, stacklevel=2)
+
+
+    # last resort, just use MatchFirst
+    return MatchFirst(parseElementClass(sym) for sym in symbols).setName(' | '.join(symbols))
+
+def dictOf( key, value ):
+    """
+    Helper to easily and clearly define a dictionary by specifying the respective patterns
+    for the key and value.  Takes care of defining the C{L{Dict}}, C{L{ZeroOrMore}}, and C{L{Group}} tokens
+    in the proper order.  The key pattern can include delimiting markers or punctuation,
+    as long as they are suppressed, thereby leaving the significant key text.  The value
+    pattern can include named results, so that the C{Dict} results can include named token
+    fields.
+
+    Example::
+        text = "shape: SQUARE posn: upper left color: light blue texture: burlap"
+        attr_expr = (label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
+        print(OneOrMore(attr_expr).parseString(text).dump())
+        
+        attr_label = label
+        attr_value = Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join)
+
+        # similar to Dict, but simpler call format
+        result = dictOf(attr_label, attr_value).parseString(text)
+        print(result.dump())
+        print(result['shape'])
+        print(result.shape)  # object attribute access works too
+        print(result.asDict())
+    prints::
+        [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']]
+        - color: light blue
+        - posn: upper left
+        - shape: SQUARE
+        - texture: burlap
+        SQUARE
+        SQUARE
+        {'color': 'light blue', 'shape': 'SQUARE', 'posn': 'upper left', 'texture': 'burlap'}
+    """
+    return Dict( ZeroOrMore( Group ( key + value ) ) )
+
+def originalTextFor(expr, asString=True):
+    """
+    Helper to return the original, untokenized text for a given expression.  Useful to
+    restore the parsed fields of an HTML start tag into the raw tag text itself, or to
+    revert separate tokens with intervening whitespace back to the original matching
+    input text. By default, returns astring containing the original parsed text.  
+       
+    If the optional C{asString} argument is passed as C{False}, then the return value is a 
+    C{L{ParseResults}} containing any results names that were originally matched, and a 
+    single token containing the original matched text from the input string.  So if 
+    the expression passed to C{L{originalTextFor}} contains expressions with defined
+    results names, you must set C{asString} to C{False} if you want to preserve those
+    results name values.
+
+    Example::
+        src = "this is test <b> bold <i>text</i> </b> normal text "
+        for tag in ("b","i"):
+            opener,closer = makeHTMLTags(tag)
+            patt = originalTextFor(opener + SkipTo(closer) + closer)
+            print(patt.searchString(src)[0])
+    prints::
+        ['<b> bold <i>text</i> </b>']
+        ['<i>text</i>']
+    """
+    locMarker = Empty().setParseAction(lambda s,loc,t: loc)
+    endlocMarker = locMarker.copy()
+    endlocMarker.callPreparse = False
+    matchExpr = locMarker("_original_start") + expr + endlocMarker("_original_end")
+    if asString:
+        extractText = lambda s,l,t: s[t._original_start:t._original_end]
+    else:
+        def extractText(s,l,t):
+            t[:] = [s[t.pop('_original_start'):t.pop('_original_end')]]
+    matchExpr.setParseAction(extractText)
+    matchExpr.ignoreExprs = expr.ignoreExprs
+    return matchExpr
+
+def ungroup(expr): 
+    """
+    Helper to undo pyparsing's default grouping of And expressions, even
+    if all but one are non-empty.
+    """
+    return TokenConverter(expr).setParseAction(lambda t:t[0])
+
+def locatedExpr(expr):
+    """
+    Helper to decorate a returned token with its starting and ending locations in the input string.
+    This helper adds the following results names:
+     - locn_start = location where matched expression begins
+     - locn_end = location where matched expression ends
+     - value = the actual parsed results
+
+    Be careful if the input text contains C{<TAB>} characters, you may want to call
+    C{L{ParserElement.parseWithTabs}}
+
+    Example::
+        wd = Word(alphas)
+        for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"):
+            print(match)
+    prints::
+        [[0, 'ljsdf', 5]]
+        [[8, 'lksdjjf', 15]]
+        [[18, 'lkkjj', 23]]
+    """
+    locator = Empty().setParseAction(lambda s,l,t: l)
+    return Group(locator("locn_start") + expr("value") + locator.copy().leaveWhitespace()("locn_end"))
+
+
+# convenience constants for positional expressions
+empty       = Empty().setName("empty")
+lineStart   = LineStart().setName("lineStart")
+lineEnd     = LineEnd().setName("lineEnd")
+stringStart = StringStart().setName("stringStart")
+stringEnd   = StringEnd().setName("stringEnd")
+
+_escapedPunc = Word( _bslash, r"\[]-*.$+^?()~ ", exact=2 ).setParseAction(lambda s,l,t:t[0][1])
+_escapedHexChar = Regex(r"\\0?[xX][0-9a-fA-F]+").setParseAction(lambda s,l,t:unichr(int(t[0].lstrip(r'\0x'),16)))
+_escapedOctChar = Regex(r"\\0[0-7]+").setParseAction(lambda s,l,t:unichr(int(t[0][1:],8)))
+_singleChar = _escapedPunc | _escapedHexChar | _escapedOctChar | CharsNotIn(r'\]', exact=1)
+_charRange = Group(_singleChar + Suppress("-") + _singleChar)
+_reBracketExpr = Literal("[") + Optional("^").setResultsName("negate") + Group( OneOrMore( _charRange | _singleChar ) ).setResultsName("body") + "]"
+
+def srange(s):
+    r"""
+    Helper to easily define string ranges for use in Word construction.  Borrows
+    syntax from regexp '[]' string range definitions::
+        srange("[0-9]")   -> "0123456789"
+        srange("[a-z]")   -> "abcdefghijklmnopqrstuvwxyz"
+        srange("[a-z$_]") -> "abcdefghijklmnopqrstuvwxyz$_"
+    The input string must be enclosed in []'s, and the returned string is the expanded
+    character set joined into a single string.
+    The values enclosed in the []'s may be:
+     - a single character
+     - an escaped character with a leading backslash (such as C{\-} or C{\]})
+     - an escaped hex character with a leading C{'\x'} (C{\x21}, which is a C{'!'} character) 
+         (C{\0x##} is also supported for backwards compatibility) 
+     - an escaped octal character with a leading C{'\0'} (C{\041}, which is a C{'!'} character)
+     - a range of any of the above, separated by a dash (C{'a-z'}, etc.)
+     - any combination of the above (C{'aeiouy'}, C{'a-zA-Z0-9_$'}, etc.)
+    """
+    _expanded = lambda p: p if not isinstance(p,ParseResults) else ''.join(unichr(c) for c in range(ord(p[0]),ord(p[1])+1))
+    try:
+        return "".join(_expanded(part) for part in _reBracketExpr.parseString(s).body)
+    except Exception:
+        return ""
+
+def matchOnlyAtCol(n):
+    """
+    Helper method for defining parse actions that require matching at a specific
+    column in the input text.
+    """
+    def verifyCol(strg,locn,toks):
+        if col(locn,strg) != n:
+            raise ParseException(strg,locn,"matched token not at column %d" % n)
+    return verifyCol
+
+def replaceWith(replStr):
+    """
+    Helper method for common parse actions that simply return a literal value.  Especially
+    useful when used with C{L{transformString<ParserElement.transformString>}()}.
+
+    Example::
+        num = Word(nums).setParseAction(lambda toks: int(toks[0]))
+        na = oneOf("N/A NA").setParseAction(replaceWith(math.nan))
+        term = na | num
+        
+        OneOrMore(term).parseString("324 234 N/A 234") # -> [324, 234, nan, 234]
+    """
+    return lambda s,l,t: [replStr]
+
+def removeQuotes(s,l,t):
+    """
+    Helper parse action for removing quotation marks from parsed quoted strings.
+
+    Example::
+        # by default, quotation marks are included in parsed results
+        quotedString.parseString("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"]
+
+        # use removeQuotes to strip quotation marks from parsed results
+        quotedString.setParseAction(removeQuotes)
+        quotedString.parseString("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"]
+    """
+    return t[0][1:-1]
+
+def tokenMap(func, *args):
+    """
+    Helper to define a parse action by mapping a function to all elements of a ParseResults list.If any additional 
+    args are passed, they are forwarded to the given function as additional arguments after
+    the token, as in C{hex_integer = Word(hexnums).setParseAction(tokenMap(int, 16))}, which will convert the
+    parsed data to an integer using base 16.
+
+    Example (compare the last to example in L{ParserElement.transformString}::
+        hex_ints = OneOrMore(Word(hexnums)).setParseAction(tokenMap(int, 16))
+        hex_ints.runTests('''
+            00 11 22 aa FF 0a 0d 1a
+            ''')
+        
+        upperword = Word(alphas).setParseAction(tokenMap(str.upper))
+        OneOrMore(upperword).runTests('''
+            my kingdom for a horse
+            ''')
+
+        wd = Word(alphas).setParseAction(tokenMap(str.title))
+        OneOrMore(wd).setParseAction(' '.join).runTests('''
+            now is the winter of our discontent made glorious summer by this sun of york
+            ''')
+    prints::
+        00 11 22 aa FF 0a 0d 1a
+        [0, 17, 34, 170, 255, 10, 13, 26]
+
+        my kingdom for a horse
+        ['MY', 'KINGDOM', 'FOR', 'A', 'HORSE']
+
+        now is the winter of our discontent made glorious summer by this sun of york
+        ['Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York']
+    """
+    def pa(s,l,t):
+        return [func(tokn, *args) for tokn in t]
+
+    try:
+        func_name = getattr(func, '__name__', 
+                            getattr(func, '__class__').__name__)
+    except Exception:
+        func_name = str(func)
+    pa.__name__ = func_name
+
+    return pa
+
+upcaseTokens = tokenMap(lambda t: _ustr(t).upper())
+"""(Deprecated) Helper parse action to convert tokens to upper case. Deprecated in favor of L{pyparsing_common.upcaseTokens}"""
+
+downcaseTokens = tokenMap(lambda t: _ustr(t).lower())
+"""(Deprecated) Helper parse action to convert tokens to lower case. Deprecated in favor of L{pyparsing_common.downcaseTokens}"""
+    
+def _makeTags(tagStr, xml):
+    """Internal helper to construct opening and closing tag expressions, given a tag name"""
+    if isinstance(tagStr,basestring):
+        resname = tagStr
+        tagStr = Keyword(tagStr, caseless=not xml)
+    else:
+        resname = tagStr.name
+
+    tagAttrName = Word(alphas,alphanums+"_-:")
+    if (xml):
+        tagAttrValue = dblQuotedString.copy().setParseAction( removeQuotes )
+        openTag = Suppress("<") + tagStr("tag") + \
+                Dict(ZeroOrMore(Group( tagAttrName + Suppress("=") + tagAttrValue ))) + \
+                Optional("/",default=[False]).setResultsName("empty").setParseAction(lambda s,l,t:t[0]=='/') + Suppress(">")
+    else:
+        printablesLessRAbrack = "".join(c for c in printables if c not in ">")
+        tagAttrValue = quotedString.copy().setParseAction( removeQuotes ) | Word(printablesLessRAbrack)
+        openTag = Suppress("<") + tagStr("tag") + \
+                Dict(ZeroOrMore(Group( tagAttrName.setParseAction(downcaseTokens) + \
+                Optional( Suppress("=") + tagAttrValue ) ))) + \
+                Optional("/",default=[False]).setResultsName("empty").setParseAction(lambda s,l,t:t[0]=='/') + Suppress(">")
+    closeTag = Combine(_L("</") + tagStr + ">")
+
+    openTag = openTag.setResultsName("start"+"".join(resname.replace(":"," ").title().split())).setName("<%s>" % resname)
+    closeTag = closeTag.setResultsName("end"+"".join(resname.replace(":"," ").title().split())).setName("</%s>" % resname)
+    openTag.tag = resname
+    closeTag.tag = resname
+    return openTag, closeTag
+
+def makeHTMLTags(tagStr):
+    """
+    Helper to construct opening and closing tag expressions for HTML, given a tag name. Matches
+    tags in either upper or lower case, attributes with namespaces and with quoted or unquoted values.
+
+    Example::
+        text = '<td>More info at the <a href="http://pyparsing.wikispaces.com">pyparsing</a> wiki page</td>'
+        # makeHTMLTags returns pyparsing expressions for the opening and closing tags as a 2-tuple
+        a,a_end = makeHTMLTags("A")
+        link_expr = a + SkipTo(a_end)("link_text") + a_end
+        
+        for link in link_expr.searchString(text):
+            # attributes in the <A> tag (like "href" shown here) are also accessible as named results
+            print(link.link_text, '->', link.href)
+    prints::
+        pyparsing -> http://pyparsing.wikispaces.com
+    """
+    return _makeTags( tagStr, False )
+
+def makeXMLTags(tagStr):
+    """
+    Helper to construct opening and closing tag expressions for XML, given a tag name. Matches
+    tags only in the given upper/lower case.
+
+    Example: similar to L{makeHTMLTags}
+    """
+    return _makeTags( tagStr, True )
+
+def withAttribute(*args,**attrDict):
+    """
+    Helper to create a validating parse action to be used with start tags created
+    with C{L{makeXMLTags}} or C{L{makeHTMLTags}}. Use C{withAttribute} to qualify a starting tag
+    with a required attribute value, to avoid false matches on common tags such as
+    C{<TD>} or C{<DIV>}.
+
+    Call C{withAttribute} with a series of attribute names and values. Specify the list
+    of filter attributes names and values as:
+     - keyword arguments, as in C{(align="right")}, or
+     - as an explicit dict with C{**} operator, when an attribute name is also a Python
+          reserved word, as in C{**{"class":"Customer", "align":"right"}}
+     - a list of name-value tuples, as in ( ("ns1:class", "Customer"), ("ns2:align","right") )
+    For attribute names with a namespace prefix, you must use the second form.  Attribute
+    names are matched insensitive to upper/lower case.
+       
+    If just testing for C{class} (with or without a namespace), use C{L{withClass}}.
+
+    To verify that the attribute exists, but without specifying a value, pass
+    C{withAttribute.ANY_VALUE} as the value.
+
+    Example::
+        html = '''
+            <div>
+            Some text
+            <div type="grid">1 4 0 1 0</div>
+            <div type="graph">1,3 2,3 1,1</div>
+            <div>this has no type</div>
+            </div>
+                
+        '''
+        div,div_end = makeHTMLTags("div")
+
+        # only match div tag having a type attribute with value "grid"
+        div_grid = div().setParseAction(withAttribute(type="grid"))
+        grid_expr = div_grid + SkipTo(div | div_end)("body")
+        for grid_header in grid_expr.searchString(html):
+            print(grid_header.body)
+        
+        # construct a match with any div tag having a type attribute, regardless of the value
+        div_any_type = div().setParseAction(withAttribute(type=withAttribute.ANY_VALUE))
+        div_expr = div_any_type + SkipTo(div | div_end)("body")
+        for div_header in div_expr.searchString(html):
+            print(div_header.body)
+    prints::
+        1 4 0 1 0
+
+        1 4 0 1 0
+        1,3 2,3 1,1
+    """
+    if args:
+        attrs = args[:]
+    else:
+        attrs = attrDict.items()
+    attrs = [(k,v) for k,v in attrs]
+    def pa(s,l,tokens):
+        for attrName,attrValue in attrs:
+            if attrName not in tokens:
+                raise ParseException(s,l,"no matching attribute " + attrName)
+            if attrValue != withAttribute.ANY_VALUE and tokens[attrName] != attrValue:
+                raise ParseException(s,l,"attribute '%s' has value '%s', must be '%s'" %
+                                            (attrName, tokens[attrName], attrValue))
+    return pa
+withAttribute.ANY_VALUE = object()
+
+def withClass(classname, namespace=''):
+    """
+    Simplified version of C{L{withAttribute}} when matching on a div class - made
+    difficult because C{class} is a reserved word in Python.
+
+    Example::
+        html = '''
+            <div>
+            Some text
+            <div class="grid">1 4 0 1 0</div>
+            <div class="graph">1,3 2,3 1,1</div>
+            <div>this &lt;div&gt; has no class</div>
+            </div>
+                
+        '''
+        div,div_end = makeHTMLTags("div")
+        div_grid = div().setParseAction(withClass("grid"))
+        
+        grid_expr = div_grid + SkipTo(div | div_end)("body")
+        for grid_header in grid_expr.searchString(html):
+            print(grid_header.body)
+        
+        div_any_type = div().setParseAction(withClass(withAttribute.ANY_VALUE))
+        div_expr = div_any_type + SkipTo(div | div_end)("body")
+        for div_header in div_expr.searchString(html):
+            print(div_header.body)
+    prints::
+        1 4 0 1 0
+
+        1 4 0 1 0
+        1,3 2,3 1,1
+    """
+    classattr = "%s:class" % namespace if namespace else "class"
+    return withAttribute(**{classattr : classname})        
+
+opAssoc = _Constants()
+opAssoc.LEFT = object()
+opAssoc.RIGHT = object()
+
+def infixNotation( baseExpr, opList, lpar=Suppress('('), rpar=Suppress(')') ):
+    """
+    Helper method for constructing grammars of expressions made up of
+    operators working in a precedence hierarchy.  Operators may be unary or
+    binary, left- or right-associative.  Parse actions can also be attached
+    to operator expressions. The generated parser will also recognize the use 
+    of parentheses to override operator precedences (see example below).
+    
+    Note: if you define a deep operator list, you may see performance issues
+    when using infixNotation. See L{ParserElement.enablePackrat} for a
+    mechanism to potentially improve your parser performance.
+
+    Parameters:
+     - baseExpr - expression representing the most basic element for the nested
+     - opList - list of tuples, one for each operator precedence level in the
+      expression grammar; each tuple is of the form
+      (opExpr, numTerms, rightLeftAssoc, parseAction), where:
+       - opExpr is the pyparsing expression for the operator;
+          may also be a string, which will be converted to a Literal;
+          if numTerms is 3, opExpr is a tuple of two expressions, for the
+          two operators separating the 3 terms
+       - numTerms is the number of terms for this operator (must
+          be 1, 2, or 3)
+       - rightLeftAssoc is the indicator whether the operator is
+          right or left associative, using the pyparsing-defined
+          constants C{opAssoc.RIGHT} and C{opAssoc.LEFT}.
+       - parseAction is the parse action to be associated with
+          expressions matching this operator expression (the
+          parse action tuple member may be omitted); if the parse action
+          is passed a tuple or list of functions, this is equivalent to
+          calling C{setParseAction(*fn)} (L{ParserElement.setParseAction})
+     - lpar - expression for matching left-parentheses (default=C{Suppress('(')})
+     - rpar - expression for matching right-parentheses (default=C{Suppress(')')})
+
+    Example::
+        # simple example of four-function arithmetic with ints and variable names
+        integer = pyparsing_common.signed_integer
+        varname = pyparsing_common.identifier 
+        
+        arith_expr = infixNotation(integer | varname,
+            [
+            ('-', 1, opAssoc.RIGHT),
+            (oneOf('* /'), 2, opAssoc.LEFT),
+            (oneOf('+ -'), 2, opAssoc.LEFT),
+            ])
+        
+        arith_expr.runTests('''
+            5+3*6
+            (5+3)*6
+            -2--11
+            ''', fullDump=False)
+    prints::
+        5+3*6
+        [[5, '+', [3, '*', 6]]]
+
+        (5+3)*6
+        [[[5, '+', 3], '*', 6]]
+
+        -2--11
+        [[['-', 2], '-', ['-', 11]]]
+    """
+    ret = Forward()
+    lastExpr = baseExpr | ( lpar + ret + rpar )
+    for i,operDef in enumerate(opList):
+        opExpr,arity,rightLeftAssoc,pa = (operDef + (None,))[:4]
+        termName = "%s term" % opExpr if arity < 3 else "%s%s term" % opExpr
+        if arity == 3:
+            if opExpr is None or len(opExpr) != 2:
+                raise ValueError("if numterms=3, opExpr must be a tuple or list of two expressions")
+            opExpr1, opExpr2 = opExpr
+        thisExpr = Forward().setName(termName)
+        if rightLeftAssoc == opAssoc.LEFT:
+            if arity == 1:
+                matchExpr = FollowedBy(lastExpr + opExpr) + Group( lastExpr + OneOrMore( opExpr ) )
+            elif arity == 2:
+                if opExpr is not None:
+                    matchExpr = FollowedBy(lastExpr + opExpr + lastExpr) + Group( lastExpr + OneOrMore( opExpr + lastExpr ) )
+                else:
+                    matchExpr = FollowedBy(lastExpr+lastExpr) + Group( lastExpr + OneOrMore(lastExpr) )
+            elif arity == 3:
+                matchExpr = FollowedBy(lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr) + \
+                            Group( lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr )
+            else:
+                raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
+        elif rightLeftAssoc == opAssoc.RIGHT:
+            if arity == 1:
+                # try to avoid LR with this extra test
+                if not isinstance(opExpr, Optional):
+                    opExpr = Optional(opExpr)
+                matchExpr = FollowedBy(opExpr.expr + thisExpr) + Group( opExpr + thisExpr )
+            elif arity == 2:
+                if opExpr is not None:
+                    matchExpr = FollowedBy(lastExpr + opExpr + thisExpr) + Group( lastExpr + OneOrMore( opExpr + thisExpr ) )
+                else:
+                    matchExpr = FollowedBy(lastExpr + thisExpr) + Group( lastExpr + OneOrMore( thisExpr ) )
+            elif arity == 3:
+                matchExpr = FollowedBy(lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr) + \
+                            Group( lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr )
+            else:
+                raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
+        else:
+            raise ValueError("operator must indicate right or left associativity")
+        if pa:
+            if isinstance(pa, (tuple, list)):
+                matchExpr.setParseAction(*pa)
+            else:
+                matchExpr.setParseAction(pa)
+        thisExpr <<= ( matchExpr.setName(termName) | lastExpr )
+        lastExpr = thisExpr
+    ret <<= lastExpr
+    return ret
+
+operatorPrecedence = infixNotation
+"""(Deprecated) Former name of C{L{infixNotation}}, will be dropped in a future release."""
+
+dblQuotedString = Combine(Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*')+'"').setName("string enclosed in double quotes")
+sglQuotedString = Combine(Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*")+"'").setName("string enclosed in single quotes")
+quotedString = Combine(Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*')+'"'|
+                       Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*")+"'").setName("quotedString using single or double quotes")
+unicodeString = Combine(_L('u') + quotedString.copy()).setName("unicode string literal")
+
+def nestedExpr(opener="(", closer=")", content=None, ignoreExpr=quotedString.copy()):
+    """
+    Helper method for defining nested lists enclosed in opening and closing
+    delimiters ("(" and ")" are the default).
+
+    Parameters:
+     - opener - opening character for a nested list (default=C{"("}); can also be a pyparsing expression
+     - closer - closing character for a nested list (default=C{")"}); can also be a pyparsing expression
+     - content - expression for items within the nested lists (default=C{None})
+     - ignoreExpr - expression for ignoring opening and closing delimiters (default=C{quotedString})
+
+    If an expression is not provided for the content argument, the nested
+    expression will capture all whitespace-delimited content between delimiters
+    as a list of separate values.
+
+    Use the C{ignoreExpr} argument to define expressions that may contain
+    opening or closing characters that should not be treated as opening
+    or closing characters for nesting, such as quotedString or a comment
+    expression.  Specify multiple expressions using an C{L{Or}} or C{L{MatchFirst}}.
+    The default is L{quotedString}, but if no expressions are to be ignored,
+    then pass C{None} for this argument.
+
+    Example::
+        data_type = oneOf("void int short long char float double")
+        decl_data_type = Combine(data_type + Optional(Word('*')))
+        ident = Word(alphas+'_', alphanums+'_')
+        number = pyparsing_common.number
+        arg = Group(decl_data_type + ident)
+        LPAR,RPAR = map(Suppress, "()")
+
+        code_body = nestedExpr('{', '}', ignoreExpr=(quotedString | cStyleComment))
+
+        c_function = (decl_data_type("type") 
+                      + ident("name")
+                      + LPAR + Optional(delimitedList(arg), [])("args") + RPAR 
+                      + code_body("body"))
+        c_function.ignore(cStyleComment)
+        
+        source_code = '''
+            int is_odd(int x) { 
+                return (x%2); 
+            }
+                
+            int dec_to_hex(char hchar) { 
+                if (hchar >= '0' && hchar <= '9') { 
+                    return (ord(hchar)-ord('0')); 
+                } else { 
+                    return (10+ord(hchar)-ord('A'));
+                } 
+            }
+        '''
+        for func in c_function.searchString(source_code):
+            print("%(name)s (%(type)s) args: %(args)s" % func)
+
+    prints::
+        is_odd (int) args: [['int', 'x']]
+        dec_to_hex (int) args: [['char', 'hchar']]
+    """
+    if opener == closer:
+        raise ValueError("opening and closing strings cannot be the same")
+    if content is None:
+        if isinstance(opener,basestring) and isinstance(closer,basestring):
+            if len(opener) == 1 and len(closer)==1:
+                if ignoreExpr is not None:
+                    content = (Combine(OneOrMore(~ignoreExpr +
+                                    CharsNotIn(opener+closer+ParserElement.DEFAULT_WHITE_CHARS,exact=1))
+                                ).setParseAction(lambda t:t[0].strip()))
+                else:
+                    content = (empty.copy()+CharsNotIn(opener+closer+ParserElement.DEFAULT_WHITE_CHARS
+                                ).setParseAction(lambda t:t[0].strip()))
+            else:
+                if ignoreExpr is not None:
+                    content = (Combine(OneOrMore(~ignoreExpr + 
+                                    ~Literal(opener) + ~Literal(closer) +
+                                    CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS,exact=1))
+                                ).setParseAction(lambda t:t[0].strip()))
+                else:
+                    content = (Combine(OneOrMore(~Literal(opener) + ~Literal(closer) +
+                                    CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS,exact=1))
+                                ).setParseAction(lambda t:t[0].strip()))
+        else:
+            raise ValueError("opening and closing arguments must be strings if no content expression is given")
+    ret = Forward()
+    if ignoreExpr is not None:
+        ret <<= Group( Suppress(opener) + ZeroOrMore( ignoreExpr | ret | content ) + Suppress(closer) )
+    else:
+        ret <<= Group( Suppress(opener) + ZeroOrMore( ret | content )  + Suppress(closer) )
+    ret.setName('nested %s%s expression' % (opener,closer))
+    return ret
+
+def indentedBlock(blockStatementExpr, indentStack, indent=True):
+    """
+    Helper method for defining space-delimited indentation blocks, such as
+    those used to define block statements in Python source code.
+
+    Parameters:
+     - blockStatementExpr - expression defining syntax of statement that
+            is repeated within the indented block
+     - indentStack - list created by caller to manage indentation stack
+            (multiple statementWithIndentedBlock expressions within a single grammar
+            should share a common indentStack)
+     - indent - boolean indicating whether block must be indented beyond the
+            the current level; set to False for block of left-most statements
+            (default=C{True})
+
+    A valid block must contain at least one C{blockStatement}.
+
+    Example::
+        data = '''
+        def A(z):
+          A1
+          B = 100
+          G = A2
+          A2
+          A3
+        B
+        def BB(a,b,c):
+          BB1
+          def BBA():
+            bba1
+            bba2
+            bba3
+        C
+        D
+        def spam(x,y):
+             def eggs(z):
+                 pass
+        '''
+
+
+        indentStack = [1]
+        stmt = Forward()
+
+        identifier = Word(alphas, alphanums)
+        funcDecl = ("def" + identifier + Group( "(" + Optional( delimitedList(identifier) ) + ")" ) + ":")
+        func_body = indentedBlock(stmt, indentStack)
+        funcDef = Group( funcDecl + func_body )
+
+        rvalue = Forward()
+        funcCall = Group(identifier + "(" + Optional(delimitedList(rvalue)) + ")")
+        rvalue << (funcCall | identifier | Word(nums))
+        assignment = Group(identifier + "=" + rvalue)
+        stmt << ( funcDef | assignment | identifier )
+
+        module_body = OneOrMore(stmt)
+
+        parseTree = module_body.parseString(data)
+        parseTree.pprint()
+    prints::
+        [['def',
+          'A',
+          ['(', 'z', ')'],
+          ':',
+          [['A1'], [['B', '=', '100']], [['G', '=', 'A2']], ['A2'], ['A3']]],
+         'B',
+         ['def',
+          'BB',
+          ['(', 'a', 'b', 'c', ')'],
+          ':',
+          [['BB1'], [['def', 'BBA', ['(', ')'], ':', [['bba1'], ['bba2'], ['bba3']]]]]],
+         'C',
+         'D',
+         ['def',
+          'spam',
+          ['(', 'x', 'y', ')'],
+          ':',
+          [[['def', 'eggs', ['(', 'z', ')'], ':', [['pass']]]]]]] 
+    """
+    def checkPeerIndent(s,l,t):
+        if l >= len(s): return
+        curCol = col(l,s)
+        if curCol != indentStack[-1]:
+            if curCol > indentStack[-1]:
+                raise ParseFatalException(s,l,"illegal nesting")
+            raise ParseException(s,l,"not a peer entry")
+
+    def checkSubIndent(s,l,t):
+        curCol = col(l,s)
+        if curCol > indentStack[-1]:
+            indentStack.append( curCol )
+        else:
+            raise ParseException(s,l,"not a subentry")
+
+    def checkUnindent(s,l,t):
+        if l >= len(s): return
+        curCol = col(l,s)
+        if not(indentStack and curCol < indentStack[-1] and curCol <= indentStack[-2]):
+            raise ParseException(s,l,"not an unindent")
+        indentStack.pop()
+
+    NL = OneOrMore(LineEnd().setWhitespaceChars("\t ").suppress())
+    INDENT = (Empty() + Empty().setParseAction(checkSubIndent)).setName('INDENT')
+    PEER   = Empty().setParseAction(checkPeerIndent).setName('')
+    UNDENT = Empty().setParseAction(checkUnindent).setName('UNINDENT')
+    if indent:
+        smExpr = Group( Optional(NL) +
+            #~ FollowedBy(blockStatementExpr) +
+            INDENT + (OneOrMore( PEER + Group(blockStatementExpr) + Optional(NL) )) + UNDENT)
+    else:
+        smExpr = Group( Optional(NL) +
+            (OneOrMore( PEER + Group(blockStatementExpr) + Optional(NL) )) )
+    blockStatementExpr.ignore(_bslash + LineEnd())
+    return smExpr.setName('indented block')
+
+alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xff]")
+punc8bit = srange(r"[\0xa1-\0xbf\0xd7\0xf7]")
+
+anyOpenTag,anyCloseTag = makeHTMLTags(Word(alphas,alphanums+"_:").setName('any tag'))
+_htmlEntityMap = dict(zip("gt lt amp nbsp quot apos".split(),'><& "\''))
+commonHTMLEntity = Regex('&(?P<entity>' + '|'.join(_htmlEntityMap.keys()) +");").setName("common HTML entity")
+def replaceHTMLEntity(t):
+    """Helper parser action to replace common HTML entities with their special characters"""
+    return _htmlEntityMap.get(t.entity)
+
+# it's easy to get these comment structures wrong - they're very common, so may as well make them available
+cStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/').setName("C style comment")
+"Comment of the form C{/* ... */}"
+
+htmlComment = Regex(r"<!--[\s\S]*?-->").setName("HTML comment")
+"Comment of the form C{<!-- ... -->}"
+
+restOfLine = Regex(r".*").leaveWhitespace().setName("rest of line")
+dblSlashComment = Regex(r"//(?:\\\n|[^\n])*").setName("// comment")
+"Comment of the form C{// ... (to end of line)}"
+
+cppStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/'| dblSlashComment).setName("C++ style comment")
+"Comment of either form C{L{cStyleComment}} or C{L{dblSlashComment}}"
+
+javaStyleComment = cppStyleComment
+"Same as C{L{cppStyleComment}}"
+
+pythonStyleComment = Regex(r"#.*").setName("Python style comment")
+"Comment of the form C{# ... (to end of line)}"
+
+_commasepitem = Combine(OneOrMore(Word(printables, excludeChars=',') +
+                                  Optional( Word(" \t") +
+                                            ~Literal(",") + ~LineEnd() ) ) ).streamline().setName("commaItem")
+commaSeparatedList = delimitedList( Optional( quotedString.copy() | _commasepitem, default="") ).setName("commaSeparatedList")
+"""(Deprecated) Predefined expression of 1 or more printable words or quoted strings, separated by commas.
+   This expression is deprecated in favor of L{pyparsing_common.comma_separated_list}."""
+
+# some other useful expressions - using lower-case class name since we are really using this as a namespace
+class pyparsing_common:
+    """
+    Here are some common low-level expressions that may be useful in jump-starting parser development:
+     - numeric forms (L{integers<integer>}, L{reals<real>}, L{scientific notation<sci_real>})
+     - common L{programming identifiers<identifier>}
+     - network addresses (L{MAC<mac_address>}, L{IPv4<ipv4_address>}, L{IPv6<ipv6_address>})
+     - ISO8601 L{dates<iso8601_date>} and L{datetime<iso8601_datetime>}
+     - L{UUID<uuid>}
+     - L{comma-separated list<comma_separated_list>}
+    Parse actions:
+     - C{L{convertToInteger}}
+     - C{L{convertToFloat}}
+     - C{L{convertToDate}}
+     - C{L{convertToDatetime}}
+     - C{L{stripHTMLTags}}
+     - C{L{upcaseTokens}}
+     - C{L{downcaseTokens}}
+
+    Example::
+        pyparsing_common.number.runTests('''
+            # any int or real number, returned as the appropriate type
+            100
+            -100
+            +100
+            3.14159
+            6.02e23
+            1e-12
+            ''')
+
+        pyparsing_common.fnumber.runTests('''
+            # any int or real number, returned as float
+            100
+            -100
+            +100
+            3.14159
+            6.02e23
+            1e-12
+            ''')
+
+        pyparsing_common.hex_integer.runTests('''
+            # hex numbers
+            100
+            FF
+            ''')
+
+        pyparsing_common.fraction.runTests('''
+            # fractions
+            1/2
+            -3/4
+            ''')
+
+        pyparsing_common.mixed_integer.runTests('''
+            # mixed fractions
+            1
+            1/2
+            -3/4
+            1-3/4
+            ''')
+
+        import uuid
+        pyparsing_common.uuid.setParseAction(tokenMap(uuid.UUID))
+        pyparsing_common.uuid.runTests('''
+            # uuid
+            12345678-1234-5678-1234-567812345678
+            ''')
+    prints::
+        # any int or real number, returned as the appropriate type
+        100
+        [100]
+
+        -100
+        [-100]
+
+        +100
+        [100]
+
+        3.14159
+        [3.14159]
+
+        6.02e23
+        [6.02e+23]
+
+        1e-12
+        [1e-12]
+
+        # any int or real number, returned as float
+        100
+        [100.0]
+
+        -100
+        [-100.0]
+
+        +100
+        [100.0]
+
+        3.14159
+        [3.14159]
+
+        6.02e23
+        [6.02e+23]
+
+        1e-12
+        [1e-12]
+
+        # hex numbers
+        100
+        [256]
+
+        FF
+        [255]
+
+        # fractions
+        1/2
+        [0.5]
+
+        -3/4
+        [-0.75]
+
+        # mixed fractions
+        1
+        [1]
+
+        1/2
+        [0.5]
+
+        -3/4
+        [-0.75]
+
+        1-3/4
+        [1.75]
+
+        # uuid
+        12345678-1234-5678-1234-567812345678
+        [UUID('12345678-1234-5678-1234-567812345678')]
+    """
+
+    convertToInteger = tokenMap(int)
+    """
+    Parse action for converting parsed integers to Python int
+    """
+
+    convertToFloat = tokenMap(float)
+    """
+    Parse action for converting parsed numbers to Python float
+    """
+
+    integer = Word(nums).setName("integer").setParseAction(convertToInteger)
+    """expression that parses an unsigned integer, returns an int"""
+
+    hex_integer = Word(hexnums).setName("hex integer").setParseAction(tokenMap(int,16))
+    """expression that parses a hexadecimal integer, returns an int"""
+
+    signed_integer = Regex(r'[+-]?\d+').setName("signed integer").setParseAction(convertToInteger)
+    """expression that parses an integer with optional leading sign, returns an int"""
+
+    fraction = (signed_integer().setParseAction(convertToFloat) + '/' + signed_integer().setParseAction(convertToFloat)).setName("fraction")
+    """fractional expression of an integer divided by an integer, returns a float"""
+    fraction.addParseAction(lambda t: t[0]/t[-1])
+
+    mixed_integer = (fraction | signed_integer + Optional(Optional('-').suppress() + fraction)).setName("fraction or mixed integer-fraction")
+    """mixed integer of the form 'integer - fraction', with optional leading integer, returns float"""
+    mixed_integer.addParseAction(sum)
+
+    real = Regex(r'[+-]?\d+\.\d*').setName("real number").setParseAction(convertToFloat)
+    """expression that parses a floating point number and returns a float"""
+
+    sci_real = Regex(r'[+-]?\d+([eE][+-]?\d+|\.\d*([eE][+-]?\d+)?)').setName("real number with scientific notation").setParseAction(convertToFloat)
+    """expression that parses a floating point number with optional scientific notation and returns a float"""
+
+    # streamlining this expression makes the docs nicer-looking
+    number = (sci_real | real | signed_integer).streamline()
+    """any numeric expression, returns the corresponding Python type"""
+
+    fnumber = Regex(r'[+-]?\d+\.?\d*([eE][+-]?\d+)?').setName("fnumber").setParseAction(convertToFloat)
+    """any int or real number, returned as float"""
+    
+    identifier = Word(alphas+'_', alphanums+'_').setName("identifier")
+    """typical code identifier (leading alpha or '_', followed by 0 or more alphas, nums, or '_')"""
+    
+    ipv4_address = Regex(r'(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})(\.(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})){3}').setName("IPv4 address")
+    "IPv4 address (C{0.0.0.0 - 255.255.255.255})"
+
+    _ipv6_part = Regex(r'[0-9a-fA-F]{1,4}').setName("hex_integer")
+    _full_ipv6_address = (_ipv6_part + (':' + _ipv6_part)*7).setName("full IPv6 address")
+    _short_ipv6_address = (Optional(_ipv6_part + (':' + _ipv6_part)*(0,6)) + "::" + Optional(_ipv6_part + (':' + _ipv6_part)*(0,6))).setName("short IPv6 address")
+    _short_ipv6_address.addCondition(lambda t: sum(1 for tt in t if pyparsing_common._ipv6_part.matches(tt)) < 8)
+    _mixed_ipv6_address = ("::ffff:" + ipv4_address).setName("mixed IPv6 address")
+    ipv6_address = Combine((_full_ipv6_address | _mixed_ipv6_address | _short_ipv6_address).setName("IPv6 address")).setName("IPv6 address")
+    "IPv6 address (long, short, or mixed form)"
+    
+    mac_address = Regex(r'[0-9a-fA-F]{2}([:.-])[0-9a-fA-F]{2}(?:\1[0-9a-fA-F]{2}){4}').setName("MAC address")
+    "MAC address xx:xx:xx:xx:xx (may also have '-' or '.' delimiters)"
+
+    @staticmethod
+    def convertToDate(fmt="%Y-%m-%d"):
+        """
+        Helper to create a parse action for converting parsed date string to Python datetime.date
+
+        Params -
+         - fmt - format to be passed to datetime.strptime (default=C{"%Y-%m-%d"})
+
+        Example::
+            date_expr = pyparsing_common.iso8601_date.copy()
+            date_expr.setParseAction(pyparsing_common.convertToDate())
+            print(date_expr.parseString("1999-12-31"))
+        prints::
+            [datetime.date(1999, 12, 31)]
+        """
+        def cvt_fn(s,l,t):
+            try:
+                return datetime.strptime(t[0], fmt).date()
+            except ValueError as ve:
+                raise ParseException(s, l, str(ve))
+        return cvt_fn
+
+    @staticmethod
+    def convertToDatetime(fmt="%Y-%m-%dT%H:%M:%S.%f"):
+        """
+        Helper to create a parse action for converting parsed datetime string to Python datetime.datetime
+
+        Params -
+         - fmt - format to be passed to datetime.strptime (default=C{"%Y-%m-%dT%H:%M:%S.%f"})
+
+        Example::
+            dt_expr = pyparsing_common.iso8601_datetime.copy()
+            dt_expr.setParseAction(pyparsing_common.convertToDatetime())
+            print(dt_expr.parseString("1999-12-31T23:59:59.999"))
+        prints::
+            [datetime.datetime(1999, 12, 31, 23, 59, 59, 999000)]
+        """
+        def cvt_fn(s,l,t):
+            try:
+                return datetime.strptime(t[0], fmt)
+            except ValueError as ve:
+                raise ParseException(s, l, str(ve))
+        return cvt_fn
+
+    iso8601_date = Regex(r'(?P<year>\d{4})(?:-(?P<month>\d\d)(?:-(?P<day>\d\d))?)?').setName("ISO8601 date")
+    "ISO8601 date (C{yyyy-mm-dd})"
+
+    iso8601_datetime = Regex(r'(?P<year>\d{4})-(?P<month>\d\d)-(?P<day>\d\d)[T ](?P<hour>\d\d):(?P<minute>\d\d)(:(?P<second>\d\d(\.\d*)?)?)?(?P<tz>Z|[+-]\d\d:?\d\d)?').setName("ISO8601 datetime")
+    "ISO8601 datetime (C{yyyy-mm-ddThh:mm:ss.s(Z|+-00:00)}) - trailing seconds, milliseconds, and timezone optional; accepts separating C{'T'} or C{' '}"
+
+    uuid = Regex(r'[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}').setName("UUID")
+    "UUID (C{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx})"
+
+    _html_stripper = anyOpenTag.suppress() | anyCloseTag.suppress()
+    @staticmethod
+    def stripHTMLTags(s, l, tokens):
+        """
+        Parse action to remove HTML tags from web page HTML source
+
+        Example::
+            # strip HTML links from normal text 
+            text = '<td>More info at the <a href="http://pyparsing.wikispaces.com">pyparsing</a> wiki page</td>'
+            td,td_end = makeHTMLTags("TD")
+            table_text = td + SkipTo(td_end).setParseAction(pyparsing_common.stripHTMLTags)("body") + td_end
+            
+            print(table_text.parseString(text).body) # -> 'More info at the pyparsing wiki page'
+        """
+        return pyparsing_common._html_stripper.transformString(tokens[0])
+
+    _commasepitem = Combine(OneOrMore(~Literal(",") + ~LineEnd() + Word(printables, excludeChars=',') 
+                                        + Optional( White(" \t") ) ) ).streamline().setName("commaItem")
+    comma_separated_list = delimitedList( Optional( quotedString.copy() | _commasepitem, default="") ).setName("comma separated list")
+    """Predefined expression of 1 or more printable words or quoted strings, separated by commas."""
+
+    upcaseTokens = staticmethod(tokenMap(lambda t: _ustr(t).upper()))
+    """Parse action to convert tokens to upper case."""
+
+    downcaseTokens = staticmethod(tokenMap(lambda t: _ustr(t).lower()))
+    """Parse action to convert tokens to lower case."""
+
+
+if __name__ == "__main__":
+
+    selectToken    = CaselessLiteral("select")
+    fromToken      = CaselessLiteral("from")
+
+    ident          = Word(alphas, alphanums + "_$")
+
+    columnName     = delimitedList(ident, ".", combine=True).setParseAction(upcaseTokens)
+    columnNameList = Group(delimitedList(columnName)).setName("columns")
+    columnSpec     = ('*' | columnNameList)
+
+    tableName      = delimitedList(ident, ".", combine=True).setParseAction(upcaseTokens)
+    tableNameList  = Group(delimitedList(tableName)).setName("tables")
+    
+    simpleSQL      = selectToken("command") + columnSpec("columns") + fromToken + tableNameList("tables")
+
+    # demo runTests method, including embedded comments in test string
+    simpleSQL.runTests("""
+        # '*' as column list and dotted table name
+        select * from SYS.XYZZY
+
+        # caseless match on "SELECT", and casts back to "select"
+        SELECT * from XYZZY, ABC
+
+        # list of column names, and mixed case SELECT keyword
+        Select AA,BB,CC from Sys.dual
+
+        # multiple tables
+        Select A, B, C from Sys.dual, Table2
+
+        # invalid SELECT keyword - should fail
+        Xelect A, B, C from Sys.dual
+
+        # incomplete command - should fail
+        Select
+
+        # invalid column name - should fail
+        Select ^^^ frox Sys.dual
+
+        """)
+
+    pyparsing_common.number.runTests("""
+        100
+        -100
+        +100
+        3.14159
+        6.02e23
+        1e-12
+        """)
+
+    # any int or real number, returned as float
+    pyparsing_common.fnumber.runTests("""
+        100
+        -100
+        +100
+        3.14159
+        6.02e23
+        1e-12
+        """)
+
+    pyparsing_common.hex_integer.runTests("""
+        100
+        FF
+        """)
+
+    import uuid
+    pyparsing_common.uuid.setParseAction(tokenMap(uuid.UUID))
+    pyparsing_common.uuid.runTests("""
+        12345678-1234-5678-1234-567812345678
+        """)