diff env/lib/python3.9/site-packages/pip/_vendor/pyparsing.py @ 0:4f3585e2f14b draft default tip

"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"
author shellac
date Mon, 22 Mar 2021 18:12:50 +0000
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+++ b/env/lib/python3.9/site-packages/pip/_vendor/pyparsing.py	Mon Mar 22 18:12:50 2021 +0000
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+# -*- coding: utf-8 -*-
+# module pyparsing.py
+#
+# Copyright (c) 2003-2019  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
+``"<salutation>, <addressee>!"``), built up using :class:`Word`,
+:class:`Literal`, and :class:`And` elements
+(the :class:`'+'<ParserElement.__add__>` operators create :class:`And` expressions,
+and the strings are auto-converted to :class:`Literal` expressions)::
+
+    from pip._vendor.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 :class:`ParseResults` object returned from
+:class:`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 :class:`ParserElement` and :class:`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 :class:`Literal` and
+   :class:`CaselessLiteral` classes
+ - construct character word-group expressions using the :class:`Word`
+   class
+ - see how to create repetitive expressions using :class:`ZeroOrMore`
+   and :class:`OneOrMore` classes
+ - use :class:`'+'<And>`, :class:`'|'<MatchFirst>`, :class:`'^'<Or>`,
+   and :class:`'&'<Each>` operators to combine simple expressions into
+   more complex ones
+ - associate names with your parsed results using
+   :class:`ParserElement.setResultsName`
+ - access the parsed data, which is returned as a :class:`ParseResults`
+   object
+ - find some helpful expression short-cuts like :class:`delimitedList`
+   and :class:`oneOf`
+ - find more useful common expressions in the :class:`pyparsing_common`
+   namespace class
+"""
+
+__version__ = "2.4.7"
+__versionTime__ = "30 Mar 2020 00:43 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
+from operator import itemgetter
+import itertools
+from functools import wraps
+from contextlib import contextmanager
+
+try:
+    # Python 3
+    from itertools import filterfalse
+except ImportError:
+    from itertools import ifilterfalse as filterfalse
+
+try:
+    from _thread import RLock
+except ImportError:
+    from threading import RLock
+
+try:
+    # Python 3
+    from collections.abc import Iterable
+    from collections.abc import MutableMapping, Mapping
+except ImportError:
+    # Python 2.7
+    from collections import Iterable
+    from collections import MutableMapping, Mapping
+
+try:
+    from collections import OrderedDict as _OrderedDict
+except ImportError:
+    try:
+        from ordereddict import OrderedDict as _OrderedDict
+    except ImportError:
+        _OrderedDict = None
+
+try:
+    from types import SimpleNamespace
+except ImportError:
+    class SimpleNamespace: pass
+
+# version compatibility configuration
+__compat__ = SimpleNamespace()
+__compat__.__doc__ = """
+    A cross-version compatibility configuration for pyparsing features that will be
+    released in a future version. By setting values in this configuration to True,
+    those features can be enabled in prior versions for compatibility development
+    and testing.
+
+     - collect_all_And_tokens - flag to enable fix for Issue #63 that fixes erroneous grouping
+       of results names when an And expression is nested within an Or or MatchFirst; set to
+       True to enable bugfix released in pyparsing 2.3.0, or False to preserve
+       pre-2.3.0 handling of named results
+"""
+__compat__.collect_all_And_tokens = True
+
+__diag__ = SimpleNamespace()
+__diag__.__doc__ = """
+Diagnostic configuration (all default to False)
+     - warn_multiple_tokens_in_named_alternation - flag to enable warnings when a results
+       name is defined on a MatchFirst or Or expression with one or more And subexpressions
+       (only warns if __compat__.collect_all_And_tokens is False)
+     - warn_ungrouped_named_tokens_in_collection - flag to enable warnings when a results
+       name is defined on a containing expression with ungrouped subexpressions that also
+       have results names
+     - warn_name_set_on_empty_Forward - flag to enable warnings whan a Forward is defined
+       with a results name, but has no contents defined
+     - warn_on_multiple_string_args_to_oneof - flag to enable warnings whan oneOf is
+       incorrectly called with multiple str arguments
+     - enable_debug_on_named_expressions - flag to auto-enable debug on all subsequent
+       calls to ParserElement.setName()
+"""
+__diag__.warn_multiple_tokens_in_named_alternation = False
+__diag__.warn_ungrouped_named_tokens_in_collection = False
+__diag__.warn_name_set_on_empty_Forward = False
+__diag__.warn_on_multiple_string_args_to_oneof = False
+__diag__.enable_debug_on_named_expressions = False
+__diag__._all_names = [nm for nm in vars(__diag__) if nm.startswith("enable_") or nm.startswith("warn_")]
+
+def _enable_all_warnings():
+    __diag__.warn_multiple_tokens_in_named_alternation = True
+    __diag__.warn_ungrouped_named_tokens_in_collection = True
+    __diag__.warn_name_set_on_empty_Forward = True
+    __diag__.warn_on_multiple_string_args_to_oneof = True
+__diag__.enable_all_warnings = _enable_all_warnings
+
+
+__all__ = ['__version__', '__versionTime__', '__author__', '__compat__', '__diag__',
+           'And', 'CaselessKeyword', 'CaselessLiteral', 'CharsNotIn', 'Combine', 'Dict', 'Each', 'Empty',
+           'FollowedBy', 'Forward', 'GoToColumn', 'Group', 'Keyword', 'LineEnd', 'LineStart', 'Literal',
+           'PrecededBy', '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', 'Char',
+           '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', 'pyparsing_unicode', 'unicode_set',
+           'conditionAsParseAction', 're',
+           ]
+
+system_version = tuple(sys.version_info)[:3]
+PY_3 = system_version[0] == 3
+if PY_3:
+    _MAX_INT = sys.maxsize
+    basestring = str
+    unichr = chr
+    unicode = str
+    _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
+
+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)
+
+
+def conditionAsParseAction(fn, message=None, fatal=False):
+    msg = message if message is not None else "failed user-defined condition"
+    exc_type = ParseFatalException if fatal else ParseException
+    fn = _trim_arity(fn)
+
+    @wraps(fn)
+    def pa(s, l, t):
+        if not bool(fn(s, l, t)):
+            raise exc_type(s, l, msg)
+
+    return pa
+
+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):
+        if self.pstr:
+            if self.loc >= len(self.pstr):
+                foundstr = ', found end of text'
+            else:
+                foundstr = (', found %r' % self.pstr[self.loc:self.loc + 1]).replace(r'\\', '\\')
+        else:
+            foundstr = ''
+        return ("%s%s  (at char %d), (line:%d, col:%d)" %
+                   (self.msg, foundstr, 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
+
+    """
+
+    @staticmethod
+    def explain(exc, depth=16):
+        """
+        Method to take an exception and translate the Python internal traceback into a list
+        of the pyparsing expressions that caused the exception to be raised.
+
+        Parameters:
+
+         - exc - exception raised during parsing (need not be a ParseException, in support
+           of Python exceptions that might be raised in a parse action)
+         - depth (default=16) - number of levels back in the stack trace to list expression
+           and function names; if None, the full stack trace names will be listed; if 0, only
+           the failing input line, marker, and exception string will be shown
+
+        Returns a multi-line string listing the ParserElements and/or function names in the
+        exception's stack trace.
+
+        Note: the diagnostic output will include string representations of the expressions
+        that failed to parse. These representations will be more helpful if you use `setName` to
+        give identifiable names to your expressions. Otherwise they will use the default string
+        forms, which may be cryptic to read.
+
+        explain() is only supported under Python 3.
+        """
+        import inspect
+
+        if depth is None:
+            depth = sys.getrecursionlimit()
+        ret = []
+        if isinstance(exc, ParseBaseException):
+            ret.append(exc.line)
+            ret.append(' ' * (exc.col - 1) + '^')
+        ret.append("{0}: {1}".format(type(exc).__name__, exc))
+
+        if depth > 0:
+            callers = inspect.getinnerframes(exc.__traceback__, context=depth)
+            seen = set()
+            for i, ff in enumerate(callers[-depth:]):
+                frm = ff[0]
+
+                f_self = frm.f_locals.get('self', None)
+                if isinstance(f_self, ParserElement):
+                    if frm.f_code.co_name not in ('parseImpl', '_parseNoCache'):
+                        continue
+                    if f_self in seen:
+                        continue
+                    seen.add(f_self)
+
+                    self_type = type(f_self)
+                    ret.append("{0}.{1} - {2}".format(self_type.__module__,
+                                                      self_type.__name__,
+                                                      f_self))
+                elif f_self is not None:
+                    self_type = type(f_self)
+                    ret.append("{0}.{1}".format(self_type.__module__,
+                                                self_type.__name__))
+                else:
+                    code = frm.f_code
+                    if code.co_name in ('wrapper', '<module>'):
+                        continue
+
+                    ret.append("{0}".format(code.co_name))
+
+                depth -= 1
+                if not depth:
+                    break
+
+        return '\n'.join(ret)
+
+
+class ParseFatalException(ParseBaseException):
+    """user-throwable exception thrown when inconsistent parse content
+       is found; stops all parsing immediately"""
+    pass
+
+class ParseSyntaxException(ParseFatalException):
+    """just like :class:`ParseFatalException`, but thrown internally
+    when an :class:`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 :class:`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 (``len(results)``)
+       - by list index (``results[0], results[1]``, etc.)
+       - by attribute (``results.<resultsName>`` - see :class:`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(ParseResults(toklist.__toklist), 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."""
+
+        values = _itervalues
+        """Returns an iterator of all named result values."""
+
+        items = _iteritems
+        """Returns an iterator of all named result key-value tuples."""
+
+    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= ``last``).
+        Supports both ``list`` and ``dict`` semantics for ``pop()``. If
+        passed no argument or an integer argument, it will use ``list``
+        semantics and pop tokens from the list of parsed tokens. If passed
+        a non-integer argument (most likely a string), it will use ``dict``
+        semantics and pop the corresponding value from any defined results
+        names. A second default return value argument is supported, just as in
+        ``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 ``defaultValue`` or ``None`` if no
+        ``defaultValue`` is specified.
+
+        Similar to ``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 ``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.__iadd__(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 ""
+
+    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 :class:`ParseResults` object.
+        """
+        ret = ParseResults(self.__toklist)
+        ret.__tokdict = dict(self.__tokdict.items())
+        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='', full=True, include_list=True, _depth=0):
+        """
+        Diagnostic method for listing out the contents of
+        a :class:`ParseResults`. Accepts an optional ``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'
+        if include_list:
+            out.append(indent + _ustr(self.asList()))
+        else:
+            out.append('')
+
+        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=indent, full=full, include_list=include_list, _depth=_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=indent,
+                                                                    full=full,
+                                                                    include_list=include_list,
+                                                                    _depth=_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
+        `pprint <https://docs.python.org/3/library/pprint.html>`_ module.
+        Accepts additional positional or keyword args as defined for
+        `pprint.pprint <https://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())
+
+    @classmethod
+    def from_dict(cls, other, name=None):
+        """
+        Helper classmethod to construct a ParseResults from a dict, preserving the
+        name-value relations as results names. If an optional 'name' argument is
+        given, a nested ParseResults will be returned
+        """
+        def is_iterable(obj):
+            try:
+                iter(obj)
+            except Exception:
+                return False
+            else:
+                if PY_3:
+                    return not isinstance(obj, (str, bytes))
+                else:
+                    return not isinstance(obj, basestring)
+
+        ret = cls([])
+        for k, v in other.items():
+            if isinstance(v, Mapping):
+                ret += cls.from_dict(v, name=k)
+            else:
+                ret += cls([v], name=k, asList=is_iterable(v))
+        if name is not None:
+            ret = cls([ret], name=name)
+        return ret
+
+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
+   :class:`ParserElement.parseString` for more
+   information on parsing strings containing ``<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 :class:`ParserElement.parseString`
+    for more information on parsing strings containing ``<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:
+                        try:
+                            del tb
+                        except NameError:
+                            pass
+
+                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
+
+    @classmethod
+    def _trim_traceback(cls, tb):
+        while tb.tb_next:
+            tb = tb.tb_next
+        return tb
+
+    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 = set(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 :class:`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 ``expr.copy()`` is just ``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 __diag__.enable_debug_on_named_expressions:
+            self.setDebug()
+        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 :class:`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,
+        ``expr("name")`` in place of ``expr.setResultsName("name")``
+        - see :class:`__call__`.
+
+        Example::
+
+            date_str = (integer.setResultsName("year") + '/'
+                        + integer.setResultsName("month") + '/'
+                        + integer.setResultsName("day"))
+
+            # equivalent form:
+            date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
+        """
+        return self._setResultsName(name, listAllMatches)
+
+    def _setResultsName(self, name, listAllMatches=False):
+        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 ``breakFlag`` to True to enable, False to
+           disable.
+        """
+        if breakFlag:
+            _parseMethod = self._parse
+            def breaker(instring, loc, doActions=True, callPreParse=True):
+                import pdb
+                # this call to pdb.set_trace() is intentional, not a checkin error
+                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 ``fn(s, loc, toks)`` ,
+        ``fn(loc, toks)`` , ``fn(toks)`` , or just ``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 :class:`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.
+
+        If None is passed as the parse action, all previously added parse actions for this
+        expression are cleared.
+
+        Optional keyword arguments:
+        - callDuringTry = (default= ``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 :class:`parseString for more
+        information on parsing strings containing ``<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]
+        """
+        if list(fns) == [None,]:
+            self.parseAction = []
+        else:
+            if not all(callable(fn) for fn in fns):
+                raise TypeError("parse actions must be callable")
+            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 :class:`setParseAction`.
+
+        See examples in :class:`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
+        :class:`setParseAction` for function call signatures. Unlike ``setParseAction``,
+        functions passed to ``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)
+        """
+        for fn in fns:
+            self.parseAction.append(conditionAsParseAction(fn, message=kwargs.get('message'),
+                                                           fatal=kwargs.get('fatal', False)))
+
+        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
+           ``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 :class:`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):
+        TRY, MATCH, FAIL = 0, 1, 2
+        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[TRY]:
+                self.debugActions[TRY](instring, loc, self)
+            try:
+                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)
+            except Exception as err:
+                # ~ print ("Exception raised:", err)
+                if self.debugActions[FAIL]:
+                    self.debugActions[FAIL](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:
+                        try:
+                            tokens = fn(instring, tokensStart, retTokens)
+                        except IndexError as parse_action_exc:
+                            exc = ParseException("exception raised in parse action")
+                            exc.__cause__ = parse_action_exc
+                            raise exc
+
+                        if tokens is not None and tokens is not retTokens:
+                            retTokens = ParseResults(tokens,
+                                                      self.resultsName,
+                                                      asList=self.saveAsList and isinstance(tokens, (ParseResults, list)),
+                                                      modal=self.modalResults)
+                except Exception as err:
+                    # ~ print "Exception raised in user parse action:", err
+                    if self.debugActions[FAIL]:
+                        self.debugActions[FAIL](instring, tokensStart, self, err)
+                    raise
+            else:
+                for fn in self.parseAction:
+                    try:
+                        tokens = fn(instring, tokensStart, retTokens)
+                    except IndexError as parse_action_exc:
+                        exc = ParseException("exception raised in parse action")
+                        exc.__cause__ = parse_action_exc
+                        raise exc
+
+                    if tokens is not None and tokens is not retTokens:
+                        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[MATCH]:
+                self.debugActions[MATCH](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= ``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 :class:`ParserElement.enablePackrat`.
+           For best results, call ``enablePackrat()`` immediately after
+           importing pyparsing.
+
+           Example::
+
+               from pip._vendor 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.
+
+        Returns the parsed data as a :class:`ParseResults` object, which may be
+        accessed as a list, or as a dict or object with attributes if the given parser
+        includes results names.
+
+        If you want the grammar to require that the entire input string be
+        successfully parsed, then set ``parseAll`` to True (equivalent to ending
+        the grammar with ``StringEnd()``).
+
+        Note: ``parseString`` implicitly calls ``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 ``loc`` argument to index into the
+        string being parsed, you can ensure you have a consistent view of the input
+        string by:
+
+        - calling ``parseWithTabs`` on your grammar before calling ``parseString``
+          (see :class:`parseWithTabs`)
+        - define your parse action using the full ``(s, loc, toks)`` signature, and
+          reference the input string using the parse action's ``s`` argument
+        - explictly expand the tabs in your input string before calling
+          ``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, clearing out pyparsing internal stack trace
+                if getattr(exc, '__traceback__', None) is not None:
+                    exc.__traceback__ = self._trim_traceback(exc.__traceback__)
+                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
+        ``maxMatches`` argument, to clip scanning after 'n' matches are found.  If
+        ``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 :class:`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, clearing out pyparsing internal stack trace
+                if getattr(exc, '__traceback__', None) is not None:
+                    exc.__traceback__ = self._trim_traceback(exc.__traceback__)
+                raise exc
+
+    def transformString(self, instring):
+        """
+        Extension to :class:`scanString`, to modify matching text with modified tokens that may
+        be returned from a parse action.  To use ``transformString``, define a grammar and
+        attach a parse action to it that modifies the returned token list.
+        Invoking ``transformString()`` on a target string will then scan for matches,
+        and replace the matched text patterns according to the logic in the parse
+        action.  ``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, clearing out pyparsing internal stack trace
+                if getattr(exc, '__traceback__', None) is not None:
+                    exc.__traceback__ = self._trim_traceback(exc.__traceback__)
+                raise exc
+
+    def searchString(self, instring, maxMatches=_MAX_INT):
+        """
+        Another extension to :class:`scanString`, simplifying the access to the tokens found
+        to match the given parse expression.  May be called with optional
+        ``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, clearing out pyparsing internal stack trace
+                if getattr(exc, '__traceback__', None) is not None:
+                    exc.__traceback__ = self._trim_traceback(exc.__traceback__)
+                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 ``maxsplit`` argument, to limit the number of splits;
+        and the optional ``includeSeparators`` argument (default= ``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 :class:`And`. Adding strings to a ParserElement
+        converts them to :class:`Literal`s by default.
+
+        Example::
+
+            greet = Word(alphas) + "," + Word(alphas) + "!"
+            hello = "Hello, World!"
+            print (hello, "->", greet.parseString(hello))
+
+        prints::
+
+            Hello, World! -> ['Hello', ',', 'World', '!']
+
+        ``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
+
+            Literal('start') + ... + Literal('end')
+
+        is equivalent to:
+
+            Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
+
+        Note that the skipped text is returned with '_skipped' as a results name,
+        and to support having multiple skips in the same parser, the value returned is
+        a list of all skipped text.
+        """
+        if other is Ellipsis:
+            return _PendingSkip(self)
+
+        if isinstance(other, basestring):
+            other = self._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 :class:`ParserElement`
+        """
+        if other is Ellipsis:
+            return SkipTo(self)("_skipped*") + self
+
+        if isinstance(other, basestring):
+            other = self._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 :class:`And` with error stop
+        """
+        if isinstance(other, basestring):
+            other = self._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 :class:`ParserElement`
+        """
+        if isinstance(other, basestring):
+            other = self._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 ``expr * 3`` in place of
+        ``expr + expr + expr``.  Expressions may also me multiplied by a 2-integer
+        tuple, similar to ``{min, max}`` multipliers in regular expressions.  Tuples
+        may also include ``None`` as in:
+         - ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
+              to ``expr*n + ZeroOrMore(expr)``
+              (read as "at least n instances of ``expr``")
+         - ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
+              (read as "0 to n instances of ``expr``")
+         - ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
+         - ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
+
+        Note that ``expr*(None, n)`` does not raise an exception if
+        more than n exprs exist in the input stream; that is,
+        ``expr*(None, n)`` does not enforce a maximum number of expr
+        occurrences.  If this behavior is desired, then write
+        ``expr*(None, n) + ~expr``
+        """
+        if other is Ellipsis:
+            other = (0, None)
+        elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
+            other = ((0, ) + other[1:] + (None,))[:2]
+
+        if isinstance(other, int):
+            minElements, optElements = other, 0
+        elif isinstance(other, tuple):
+            other = tuple(o if o is not Ellipsis else None for o in other)
+            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 :class:`MatchFirst`
+        """
+        if other is Ellipsis:
+            return _PendingSkip(self, must_skip=True)
+
+        if isinstance(other, basestring):
+            other = self._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 :class:`ParserElement`
+        """
+        if isinstance(other, basestring):
+            other = self._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 :class:`Or`
+        """
+        if isinstance(other, basestring):
+            other = self._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 :class:`ParserElement`
+        """
+        if isinstance(other, basestring):
+            other = self._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 :class:`Each`
+        """
+        if isinstance(other, basestring):
+            other = self._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 :class:`ParserElement`
+        """
+        if isinstance(other, basestring):
+            other = self._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 :class:`NotAny`
+        """
+        return NotAny(self)
+
+    def __iter__(self):
+        # must implement __iter__ to override legacy use of sequential access to __getitem__ to
+        # iterate over a sequence
+        raise TypeError('%r object is not iterable' % self.__class__.__name__)
+
+    def __getitem__(self, key):
+        """
+        use ``[]`` indexing notation as a short form for expression repetition:
+         - ``expr[n]`` is equivalent to ``expr*n``
+         - ``expr[m, n]`` is equivalent to ``expr*(m, n)``
+         - ``expr[n, ...]`` or ``expr[n,]`` is equivalent
+              to ``expr*n + ZeroOrMore(expr)``
+              (read as "at least n instances of ``expr``")
+         - ``expr[..., n]`` is equivalent to ``expr*(0, n)``
+              (read as "0 to n instances of ``expr``")
+         - ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
+         - ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
+         ``None`` may be used in place of ``...``.
+
+        Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
+        if more than ``n`` ``expr``s exist in the input stream.  If this behavior is
+        desired, then write ``expr[..., n] + ~expr``.
+       """
+
+        # convert single arg keys to tuples
+        try:
+            if isinstance(key, str):
+                key = (key,)
+            iter(key)
+        except TypeError:
+            key = (key, key)
+
+        if len(key) > 2:
+            warnings.warn("only 1 or 2 index arguments supported ({0}{1})".format(key[:5],
+                                                                                '... [{0}]'.format(len(key))
+                                                                                if len(key) > 5 else ''))
+
+        # clip to 2 elements
+        ret = self * tuple(key[:2])
+        return ret
+
+    def __call__(self, name=None):
+        """
+        Shortcut for :class:`setResultsName`, with ``listAllMatches=False``.
+
+        If ``name`` is given with a trailing ``'*'`` character, then ``listAllMatches`` will be
+        passed as ``True``.
+
+        If ``name` is omitted, same as calling :class:`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 :class:`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
+        :class:`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 ``<TAB>``s to spaces before parsing the input string.
+        Must be called before ``parseString`` when the input grammar contains elements that
+        match ``<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 ``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 :class:`setDebugActions`. Prior to attempting
+        to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
+        is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
+        message is shown. Also note the use of :class:`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 :class:`Word` expression without calling ``setName`` is ``"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=None):
+        """
+        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, clearing out pyparsing internal stack trace
+                if getattr(exc, '__traceback__', None) is not None:
+                    exc.__traceback__ = self._trim_traceback(exc.__traceback__)
+                raise exc
+
+    def __eq__(self, other):
+        if self is other:
+            return True
+        elif isinstance(other, basestring):
+            return self.matches(other)
+        elif isinstance(other, ParserElement):
+            return vars(self) == vars(other)
+        return False
+
+    def __ne__(self, other):
+        return not (self == other)
+
+    def __hash__(self):
+        return 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= ``True``) - flag to pass to :class:`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, postParse=None,
+                 file=None):
+        """
+        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= ``True``) - flag to pass to :class:`parseString` when running tests
+         - comment - (default= ``'#'``) - expression for indicating embedded comments in the test
+              string; pass None to disable comment filtering
+         - fullDump - (default= ``True``) - dump results as list followed by results names in nested outline;
+              if False, only dump nested list
+         - printResults - (default= ``True``) prints test output to stdout
+         - failureTests - (default= ``False``) indicates if these tests are expected to fail parsing
+         - postParse - (default= ``None``) optional callback for successful parse results; called as
+              `fn(test_string, parse_results)` and returns a string to be added to the test output
+         - file - (default=``None``) optional file-like object to which test output will be written;
+              if None, will default to ``sys.stdout``
+
+        Returns: a (success, results) tuple, where success indicates that all tests succeeded
+        (or failed if ``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)
+        if file is None:
+            file = sys.stdout
+        print_ = file.write
+
+        allResults = []
+        comments = []
+        success = True
+        NL = Literal(r'\n').addParseAction(replaceWith('\n')).ignore(quotedString)
+        BOM = u'\ufeff'
+        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' + '\n'.join(comments) if comments else '', t]
+            comments = []
+            try:
+                # convert newline marks to actual newlines, and strip leading BOM if present
+                t = NL.transformString(t.lstrip(BOM))
+                result = self.parseString(t, parseAll=parseAll)
+            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
+            else:
+                success = success and not failureTests
+                if postParse is not None:
+                    try:
+                        pp_value = postParse(t, result)
+                        if pp_value is not None:
+                            if isinstance(pp_value, ParseResults):
+                                out.append(pp_value.dump())
+                            else:
+                                out.append(str(pp_value))
+                        else:
+                            out.append(result.dump())
+                    except Exception as e:
+                        out.append(result.dump(full=fullDump))
+                        out.append("{0} failed: {1}: {2}".format(postParse.__name__, type(e).__name__, e))
+                else:
+                    out.append(result.dump(full=fullDump))
+
+            if printResults:
+                if fullDump:
+                    out.append('')
+                print_('\n'.join(out))
+
+            allResults.append((t, result))
+
+        return success, allResults
+
+
+class _PendingSkip(ParserElement):
+    # internal placeholder class to hold a place were '...' is added to a parser element,
+    # once another ParserElement is added, this placeholder will be replaced with a SkipTo
+    def __init__(self, expr, must_skip=False):
+        super(_PendingSkip, self).__init__()
+        self.strRepr = str(expr + Empty()).replace('Empty', '...')
+        self.name = self.strRepr
+        self.anchor = expr
+        self.must_skip = must_skip
+
+    def __add__(self, other):
+        skipper = SkipTo(other).setName("...")("_skipped*")
+        if self.must_skip:
+            def must_skip(t):
+                if not t._skipped or t._skipped.asList() == ['']:
+                    del t[0]
+                    t.pop("_skipped", None)
+            def show_skip(t):
+                if t._skipped.asList()[-1:] == ['']:
+                    skipped = t.pop('_skipped')
+                    t['_skipped'] = 'missing <' + repr(self.anchor) + '>'
+            return (self.anchor + skipper().addParseAction(must_skip)
+                    | skipper().addParseAction(show_skip)) + other
+
+        return self.anchor + skipper + other
+
+    def __repr__(self):
+        return self.strRepr
+
+    def parseImpl(self, *args):
+        raise Exception("use of `...` expression without following SkipTo target expression")
+
+
+class Token(ParserElement):
+    """Abstract :class:`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 :class:`CaselessLiteral`.
+
+    For keyword matching (force word break before and after the matched string),
+    use :class:`Keyword` or :class:`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: modify __class__ to select
+        # a parseImpl optimized for single-character check
+        if self.matchLen == 1 and type(self) is Literal:
+            self.__class__ = _SingleCharLiteral
+
+    def parseImpl(self, instring, loc, doActions=True):
+        if instring[loc] == self.firstMatchChar and instring.startswith(self.match, loc):
+            return loc + self.matchLen, self.match
+        raise ParseException(instring, loc, self.errmsg, self)
+
+class _SingleCharLiteral(Literal):
+    def parseImpl(self, instring, loc, doActions=True):
+        if instring[loc] == self.firstMatchChar:
+            return loc + 1, 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 :class:`Literal`:
+
+     - ``Literal("if")`` will match the leading ``'if'`` in
+       ``'ifAndOnlyIf'``.
+     - ``Keyword("if")`` will not; it will only match the leading
+       ``'if'`` in ``'if x=1'``, or ``'if(y==2)'``
+
+    Accepts two optional constructor arguments in addition to the
+    keyword string:
+
+     - ``identChars`` is a string of characters that would be valid
+       identifier characters, defaulting to all alphanumerics + "_" and
+       "$"
+     - ``caseless`` allows case-insensitive matching, default is ``False``.
+
+    Example::
+
+        Keyword("start").parseString("start")  # -> ['start']
+        Keyword("start").parseString("starting")  # -> Exception
+
+    For case-insensitive matching, use :class:`CaselessKeyword`.
+    """
+    DEFAULT_KEYWORD_CHARS = alphanums + "_$"
+
+    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:
+                if ((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 :class:`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 :class:`Keyword`.
+
+    Example::
+
+        OneOrMore(CaselessKeyword("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD']
+
+    (Contrast with example for :class:`CaselessLiteral`.)
+    """
+    def __init__(self, matchString, identChars=None):
+        super(CaselessKeyword, self).__init__(matchString, identChars, caseless=True)
+
+class CloseMatch(Token):
+    """A variation on :class:`Literal` which matches "close" matches,
+    that is, strings with at most 'n' mismatching characters.
+    :class:`CloseMatch` takes parameters:
+
+     - ``match_string`` - string to be matched
+     - ``maxMismatches`` - (``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:
+
+     - ``mismatches`` - a list of the positions within the
+       match_string where mismatches were found
+     - ``original`` - the original match_string used to compare
+       against the input string
+
+    If ``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], 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'] = 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 ``min`` is
+    1 (a minimum value < 1 is not valid); the default values for
+    ``max`` and ``exact`` are 0, meaning no maximum or exact
+    length restriction. An optional ``excludeChars`` parameter can
+    list characters that might be found in the input ``bodyChars``
+    string; useful to define a word of all printables except for one or
+    two characters, for instance.
+
+    :class:`srange` is useful for defining custom character set strings
+    for defining ``Word`` expressions, using range notation from
+    regular expression character sets.
+
+    A common mistake is to use :class:`Word` to match a specific literal
+    string, as in ``Word("Address")``. Remember that :class:`Word`
+    uses the string argument to define *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 :class:`Literal` or :class:`Keyword`.
+
+    pyparsing includes helper strings for building Words:
+
+     - :class:`alphas`
+     - :class:`nums`
+     - :class:`alphanums`
+     - :class:`hexnums`
+     - :class:`alphas8bit` (alphabetic characters in ASCII range 128-255
+       - accented, tilded, umlauted, etc.)
+     - :class:`punc8bit` (non-alphabetic characters in ASCII range
+       128-255 - currency, symbols, superscripts, diacriticals, etc.)
+     - :class:`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:
+            excludeChars = set(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
+            else:
+                self.re_match = self.re.match
+                self.__class__ = _WordRegex
+
+    def parseImpl(self, instring, loc, doActions=True):
+        if instring[loc] not 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
+        elif self.maxSpecified and loc < instrlen and instring[loc] in bodychars:
+            throwException = True
+        elif 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 _WordRegex(Word):
+    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()
+        return loc, result.group()
+
+
+class Char(_WordRegex):
+    """A short-cut class for defining ``Word(characters, exact=1)``,
+    when defining a match of any single character in a string of
+    characters.
+    """
+    def __init__(self, charset, asKeyword=False, excludeChars=None):
+        super(Char, self).__init__(charset, exact=1, asKeyword=asKeyword, excludeChars=excludeChars)
+        self.reString = "[%s]" % _escapeRegexRangeChars(''.join(self.initChars))
+        if asKeyword:
+            self.reString = r"\b%s\b" % self.reString
+        self.re = re.compile(self.reString)
+        self.re_match = self.re.match
+
+
+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 stdlib Python  `re module <https://docs.python.org/3/library/re.html>`_.
+    If the given regex contains named groups (defined using ``(?P<name>...)``),
+    these will be preserved as named parse results.
+
+    If instead of the Python stdlib re module you wish to use a different RE module
+    (such as the `regex` module), you can replace it by either building your
+    Regex object with a compiled RE that was compiled using regex:
+
+    Example::
+
+        realnum = Regex(r"[+-]?\d+\.\d*")
+        date = Regex(r'(?P<year>\d{4})-(?P<month>\d\d?)-(?P<day>\d\d?)')
+        # ref: https://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?{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})")
+
+        # use regex module instead of stdlib re module to construct a Regex using
+        # a compiled regular expression
+        import regex
+        parser = pp.Regex(regex.compile(r'[0-9]'))
+
+    """
+    def __init__(self, pattern, flags=0, asGroupList=False, asMatch=False):
+        """The parameters ``pattern`` and ``flags`` are passed
+        to the ``re.compile()`` function as-is. See the Python
+        `re module <https://docs.python.org/3/library/re.html>`_ 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 hasattr(pattern, 'pattern') and hasattr(pattern, 'match'):
+            self.re = pattern
+            self.pattern = self.reString = pattern.pattern
+            self.flags = flags
+
+        else:
+            raise TypeError("Regex may only be constructed with a string or a compiled RE object")
+
+        self.re_match = self.re.match
+
+        self.name = _ustr(self)
+        self.errmsg = "Expected " + self.name
+        self.mayIndexError = False
+        self.mayReturnEmpty = self.re_match("") is not None
+        self.asGroupList = asGroupList
+        self.asMatch = asMatch
+        if self.asGroupList:
+            self.parseImpl = self.parseImplAsGroupList
+        if self.asMatch:
+            self.parseImpl = self.parseImplAsMatch
+
+    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()
+        ret = ParseResults(result.group())
+        d = result.groupdict()
+        if d:
+            for k, v in d.items():
+                ret[k] = v
+        return loc, ret
+
+    def parseImplAsGroupList(self, instring, loc, doActions=True):
+        result = self.re_match(instring, loc)
+        if not result:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        loc = result.end()
+        ret = result.groups()
+        return loc, ret
+
+    def parseImplAsMatch(self, instring, loc, doActions=True):
+        result = self.re_match(instring, loc)
+        if not result:
+            raise ParseException(instring, loc, self.errmsg, self)
+
+        loc = result.end()
+        ret = result
+        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
+
+    def sub(self, repl):
+        r"""
+        Return Regex with an attached parse action to transform the parsed
+        result as if called using `re.sub(expr, repl, string) <https://docs.python.org/3/library/re.html#re.sub>`_.
+
+        Example::
+
+            make_html = Regex(r"(\w+):(.*?):").sub(r"<\1>\2</\1>")
+            print(make_html.transformString("h1:main title:"))
+            # prints "<h1>main title</h1>"
+        """
+        if self.asGroupList:
+            warnings.warn("cannot use sub() with Regex(asGroupList=True)",
+                          SyntaxWarning, stacklevel=2)
+            raise SyntaxError()
+
+        if self.asMatch and callable(repl):
+            warnings.warn("cannot use sub() with a callable with Regex(asMatch=True)",
+                          SyntaxWarning, stacklevel=2)
+            raise SyntaxError()
+
+        if self.asMatch:
+            def pa(tokens):
+                return tokens[0].expand(repl)
+        else:
+            def pa(tokens):
+                return self.re.sub(repl, tokens[0])
+        return self.addParseAction(pa)
+
+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= ``None``)
+        - escQuote - special quote sequence to escape an embedded quote
+          string (such as SQL's ``""`` to escape an embedded ``"``)
+          (default= ``None``)
+        - multiline - boolean indicating whether quotes can span
+          multiple lines (default= ``False``)
+        - unquoteResults - boolean indicating whether the matched text
+          should be unquoted (default= ``True``)
+        - endQuoteChar - string of one or more characters defining the
+          end of the quote delimited string (default= ``None``  => same as
+          quoteChar)
+        - convertWhitespaceEscapes - convert escaped whitespace
+          (``'\t'``, ``'\n'``, etc.) to actual whitespace
+          (default= ``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
+            self.re_match = self.re.match
+        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 *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 ``min`` is
+    1 (a minimum value < 1 is not valid); the default values for
+    ``max`` and ``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 ``" \\t\\r\\n"``.  Also takes optional ``min``,
+    ``max``, and ``exact`` arguments, as defined for the
+    :class:`Word` class.
+    """
+    whiteStrs = {
+        ' ' : '<SP>',
+        '\t': '<TAB>',
+        '\n': '<LF>',
+        '\r': '<CR>',
+        '\f': '<FF>',
+        u'\u00A0': '<NBSP>',
+        u'\u1680': '<OGHAM_SPACE_MARK>',
+        u'\u180E': '<MONGOLIAN_VOWEL_SEPARATOR>',
+        u'\u2000': '<EN_QUAD>',
+        u'\u2001': '<EM_QUAD>',
+        u'\u2002': '<EN_SPACE>',
+        u'\u2003': '<EM_SPACE>',
+        u'\u2004': '<THREE-PER-EM_SPACE>',
+        u'\u2005': '<FOUR-PER-EM_SPACE>',
+        u'\u2006': '<SIX-PER-EM_SPACE>',
+        u'\u2007': '<FIGURE_SPACE>',
+        u'\u2008': '<PUNCTUATION_SPACE>',
+        u'\u2009': '<THIN_SPACE>',
+        u'\u200A': '<HAIR_SPACE>',
+        u'\u200B': '<ZERO_WIDTH_SPACE>',
+        u'\u202F': '<NNBSP>',
+        u'\u205F': '<MMSP>',
+        u'\u3000': '<IDEOGRAPHIC_SPACE>',
+        }
+    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 instring[loc] not 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):
+    r"""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
+    ``wordChars`` (default= ``printables``). To emulate the
+    ``\b`` behavior of regular expressions, use
+    ``WordStart(alphanums)``. ``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 ``wordChars``
+    (default= ``printables``). To emulate the ``\b`` behavior of
+    regular expressions, use ``WordEnd(alphanums)``. ``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 = [self._literalStringClass(exprs)]
+        elif isinstance(exprs, ParserElement):
+            self.exprs = [exprs]
+        elif isinstance(exprs, Iterable):
+            exprs = list(exprs)
+            # if sequence of strings provided, wrap with Literal
+            if any(isinstance(expr, basestring) for expr in exprs):
+                exprs = (self._literalStringClass(e) if isinstance(e, basestring) else e for e in exprs)
+            self.exprs = list(exprs)
+        else:
+            try:
+                self.exprs = list(exprs)
+            except TypeError:
+                self.exprs = [exprs]
+        self.callPreparse = False
+
+    def append(self, other):
+        self.exprs.append(other)
+        self.strRepr = None
+        return self
+
+    def leaveWhitespace(self):
+        """Extends ``leaveWhitespace`` defined in base class, and also invokes ``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 validate(self, validateTrace=None):
+        tmp = (validateTrace if validateTrace is not None else [])[:] + [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
+
+    def _setResultsName(self, name, listAllMatches=False):
+        if __diag__.warn_ungrouped_named_tokens_in_collection:
+            for e in self.exprs:
+                if isinstance(e, ParserElement) and e.resultsName:
+                    warnings.warn("{0}: setting results name {1!r} on {2} expression "
+                                  "collides with {3!r} on contained expression".format("warn_ungrouped_named_tokens_in_collection",
+                                                                                       name,
+                                                                                       type(self).__name__,
+                                                                                       e.resultsName),
+                                  stacklevel=3)
+
+        return super(ParseExpression, self)._setResultsName(name, listAllMatches)
+
+
+class And(ParseExpression):
+    """
+    Requires all given :class:`ParseExpression` s to be found in the given order.
+    Expressions may be separated by whitespace.
+    May be constructed using the ``'+'`` operator.
+    May also be constructed using the ``'-'`` 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):
+        exprs = list(exprs)
+        if exprs and Ellipsis in exprs:
+            tmp = []
+            for i, expr in enumerate(exprs):
+                if expr is Ellipsis:
+                    if i < len(exprs) - 1:
+                        skipto_arg = (Empty() + exprs[i + 1]).exprs[-1]
+                        tmp.append(SkipTo(skipto_arg)("_skipped*"))
+                    else:
+                        raise Exception("cannot construct And with sequence ending in ...")
+                else:
+                    tmp.append(expr)
+            exprs[:] = tmp
+        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 streamline(self):
+        # collapse any _PendingSkip's
+        if self.exprs:
+            if any(isinstance(e, ParseExpression) and e.exprs and isinstance(e.exprs[-1], _PendingSkip)
+                   for e in self.exprs[:-1]):
+                for i, e in enumerate(self.exprs[:-1]):
+                    if e is None:
+                        continue
+                    if (isinstance(e, ParseExpression)
+                            and e.exprs and isinstance(e.exprs[-1], _PendingSkip)):
+                        e.exprs[-1] = e.exprs[-1] + self.exprs[i + 1]
+                        self.exprs[i + 1] = None
+                self.exprs = [e for e in self.exprs if e is not None]
+
+        super(And, self).streamline()
+        self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
+        return self
+
+    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 = self._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 :class:`ParseExpression` is found. If
+    two expressions match, the expression that matches the longest
+    string will be used. May be constructed using the ``'^'``
+    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 streamline(self):
+        super(Or, self).streamline()
+        if __compat__.collect_all_And_tokens:
+            self.saveAsList = any(e.saveAsList for e in self.exprs)
+        return self
+
+    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:
+            # re-evaluate all matches in descending order of length of match, in case attached actions
+            # might change whether or how much they match of the input.
+            matches.sort(key=itemgetter(0), reverse=True)
+
+            if not doActions:
+                # no further conditions or parse actions to change the selection of
+                # alternative, so the first match will be the best match
+                best_expr = matches[0][1]
+                return best_expr._parse(instring, loc, doActions)
+
+            longest = -1, None
+            for loc1, expr1 in matches:
+                if loc1 <= longest[0]:
+                    # already have a longer match than this one will deliver, we are done
+                    return longest
+
+                try:
+                    loc2, toks = expr1._parse(instring, loc, doActions)
+                except ParseException as err:
+                    err.__traceback__ = None
+                    if err.loc > maxExcLoc:
+                        maxException = err
+                        maxExcLoc = err.loc
+                else:
+                    if loc2 >= loc1:
+                        return loc2, toks
+                    # didn't match as much as before
+                    elif loc2 > longest[0]:
+                        longest = loc2, toks
+
+            if longest != (-1, None):
+                return longest
+
+        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 = self._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)
+
+    def _setResultsName(self, name, listAllMatches=False):
+        if (not __compat__.collect_all_And_tokens
+                and __diag__.warn_multiple_tokens_in_named_alternation):
+            if any(isinstance(e, And) for e in self.exprs):
+                warnings.warn("{0}: setting results name {1!r} on {2} expression "
+                              "may only return a single token for an And alternative, "
+                              "in future will return the full list of tokens".format(
+                    "warn_multiple_tokens_in_named_alternation", name, type(self).__name__),
+                    stacklevel=3)
+
+        return super(Or, self)._setResultsName(name, listAllMatches)
+
+
+class MatchFirst(ParseExpression):
+    """Requires that at least one :class:`ParseExpression` is found. If
+    two expressions match, the first one listed is the one that will
+    match. May be constructed using the ``'|'`` 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 streamline(self):
+        super(MatchFirst, self).streamline()
+        if __compat__.collect_all_And_tokens:
+            self.saveAsList = any(e.saveAsList for e in self.exprs)
+        return self
+
+    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 = self._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)
+
+    def _setResultsName(self, name, listAllMatches=False):
+        if (not __compat__.collect_all_And_tokens
+                and __diag__.warn_multiple_tokens_in_named_alternation):
+            if any(isinstance(e, And) for e in self.exprs):
+                warnings.warn("{0}: setting results name {1!r} on {2} expression "
+                              "may only return a single token for an And alternative, "
+                              "in future will return the full list of tokens".format(
+                    "warn_multiple_tokens_in_named_alternation", name, type(self).__name__),
+                    stacklevel=3)
+
+        return super(MatchFirst, self)._setResultsName(name, listAllMatches)
+
+
+class Each(ParseExpression):
+    """Requires all given :class:`ParseExpression` s to be found, but in
+    any order. Expressions may be separated by whitespace.
+
+    May be constructed using the ``'&'`` 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
+        self.saveAsList = True
+
+    def streamline(self):
+        super(Each, self).streamline()
+        self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
+        return self
+
+    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, Regex))]
+            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 :class:`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(self._literalStringClass, Token):
+                expr = self._literalStringClass(expr)
+            else:
+                expr = self._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=None):
+        if validateTrace is None:
+            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.
+    ``FollowedBy`` does *not* advance the parsing position within
+    the input string, it only verifies that the specified parse
+    expression matches at the current position.  ``FollowedBy``
+    always returns a null token list. If any results names are defined
+    in the lookahead expression, those *will* be returned for access by
+    name.
+
+    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):
+        # by using self._expr.parse and deleting the contents of the returned ParseResults list
+        # we keep any named results that were defined in the FollowedBy expression
+        _, ret = self.expr._parse(instring, loc, doActions=doActions)
+        del ret[:]
+
+        return loc, ret
+
+
+class PrecededBy(ParseElementEnhance):
+    """Lookbehind matching of the given parse expression.
+    ``PrecededBy`` does not advance the parsing position within the
+    input string, it only verifies that the specified parse expression
+    matches prior to the current position.  ``PrecededBy`` always
+    returns a null token list, but if a results name is defined on the
+    given expression, it is returned.
+
+    Parameters:
+
+     - expr - expression that must match prior to the current parse
+       location
+     - retreat - (default= ``None``) - (int) maximum number of characters
+       to lookbehind prior to the current parse location
+
+    If the lookbehind expression is a string, Literal, Keyword, or
+    a Word or CharsNotIn with a specified exact or maximum length, then
+    the retreat parameter is not required. Otherwise, retreat must be
+    specified to give a maximum number of characters to look back from
+    the current parse position for a lookbehind match.
+
+    Example::
+
+        # VB-style variable names with type prefixes
+        int_var = PrecededBy("#") + pyparsing_common.identifier
+        str_var = PrecededBy("$") + pyparsing_common.identifier
+
+    """
+    def __init__(self, expr, retreat=None):
+        super(PrecededBy, self).__init__(expr)
+        self.expr = self.expr().leaveWhitespace()
+        self.mayReturnEmpty = True
+        self.mayIndexError = False
+        self.exact = False
+        if isinstance(expr, str):
+            retreat = len(expr)
+            self.exact = True
+        elif isinstance(expr, (Literal, Keyword)):
+            retreat = expr.matchLen
+            self.exact = True
+        elif isinstance(expr, (Word, CharsNotIn)) and expr.maxLen != _MAX_INT:
+            retreat = expr.maxLen
+            self.exact = True
+        elif isinstance(expr, _PositionToken):
+            retreat = 0
+            self.exact = True
+        self.retreat = retreat
+        self.errmsg = "not preceded by " + str(expr)
+        self.skipWhitespace = False
+        self.parseAction.append(lambda s, l, t: t.__delitem__(slice(None, None)))
+
+    def parseImpl(self, instring, loc=0, doActions=True):
+        if self.exact:
+            if loc < self.retreat:
+                raise ParseException(instring, loc, self.errmsg)
+            start = loc - self.retreat
+            _, ret = self.expr._parse(instring, start)
+        else:
+            # retreat specified a maximum lookbehind window, iterate
+            test_expr = self.expr + StringEnd()
+            instring_slice = instring[max(0, loc - self.retreat):loc]
+            last_expr = ParseException(instring, loc, self.errmsg)
+            for offset in range(1, min(loc, self.retreat + 1)+1):
+                try:
+                    # print('trying', offset, instring_slice, repr(instring_slice[loc - offset:]))
+                    _, ret = test_expr._parse(instring_slice, len(instring_slice) - offset)
+                except ParseBaseException as pbe:
+                    last_expr = pbe
+                else:
+                    break
+            else:
+                raise last_expr
+        return loc, ret
+
+
+class NotAny(ParseElementEnhance):
+    """Lookahead to disallow matching with the given parse expression.
+    ``NotAny`` does *not* advance the parsing position within the
+    input string, it only verifies that the specified parse expression
+    does *not* match at the current position.  Also, ``NotAny`` does
+    *not* skip over leading whitespace. ``NotAny`` always returns
+    a null token list.  May be constructed using the '~' operator.
+
+    Example::
+
+        AND, OR, NOT = map(CaselessKeyword, "AND OR NOT".split())
+
+        # take care not to mistake keywords for identifiers
+        ident = ~(AND | OR | NOT) + Word(alphas)
+        boolean_term = Optional(NOT) + ident
+
+        # very crude boolean expression - to support parenthesis groups and
+        # operation hierarchy, use infixNotation
+        boolean_expr = boolean_term + ZeroOrMore((AND | OR) + boolean_term)
+
+        # integers that are followed by "." are actually floats
+        integer = Word(nums) + ~Char(".")
+    """
+    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 = self._literalStringClass(ender)
+        self.stopOn(ender)
+
+    def stopOn(self, ender):
+        if isinstance(ender, basestring):
+            ender = self._literalStringClass(ender)
+        self.not_ender = ~ender if ender is not None else None
+        return self
+
+    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
+
+    def _setResultsName(self, name, listAllMatches=False):
+        if __diag__.warn_ungrouped_named_tokens_in_collection:
+            for e in [self.expr] + getattr(self.expr, 'exprs', []):
+                if isinstance(e, ParserElement) and e.resultsName:
+                    warnings.warn("{0}: setting results name {1!r} on {2} expression "
+                                  "collides with {3!r} on contained expression".format("warn_ungrouped_named_tokens_in_collection",
+                                                                                       name,
+                                                                                       type(self).__name__,
+                                                                                       e.resultsName),
+                                  stacklevel=3)
+
+        return super(_MultipleMatch, self)._setResultsName(name, listAllMatches)
+
+
+class OneOrMore(_MultipleMatch):
+    """Repetition of one or more of the given expression.
+
+    Parameters:
+     - expr - expression that must match one or more times
+     - stopOn - (default= ``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= ``None``) - expression for a terminating sentinel
+          (only required if the sentinel would ordinarily match the repetition
+          expression)
+
+    Example: similar to :class:`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 ""
+
+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)
+    """
+    __optionalNotMatched = _NullToken()
+
+    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 self.__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= ``False``) if True, the target expression is also parsed
+          (the skipped text and target expression are returned as a 2-element list).
+     - ignore - (default= ``None``) used to define grammars (typically quoted strings and
+          comments) that might contain false matches to the target expression
+     - failOn - (default= ``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.saveAsList = False
+        if isinstance(failOn, basestring):
+            self.failOn = self._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 ``Forward``
+    variable using the '<<' operator.
+
+    Note: take care when assigning to ``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 ``Forward``::
+
+        fwdExpr << (a | b | c)
+
+    Converting to use the '<<=' operator instead will avoid this problem.
+
+    See :class:`ParseResults.pprint` for an example of a recursive
+    parser created using ``Forward``.
+    """
+    def __init__(self, other=None):
+        super(Forward, self).__init__(other, savelist=False)
+
+    def __lshift__(self, other):
+        if isinstance(other, basestring):
+            other = self._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=None):
+        if validateTrace is None:
+            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
+        if self.strRepr is not None:
+            return self.strRepr
+
+        # Avoid infinite recursion by setting a temporary strRepr
+        self.strRepr = ": ..."
+
+        # Use the string representation of main expression.
+        retString = '...'
+        try:
+            if self.expr is not None:
+                retString = _ustr(self.expr)[:1000]
+            else:
+                retString = "None"
+        finally:
+            self.strRepr = self.__class__.__name__ + ": " + retString
+        return self.strRepr
+
+    def copy(self):
+        if self.expr is not None:
+            return super(Forward, self).copy()
+        else:
+            ret = Forward()
+            ret <<= self
+            return ret
+
+    def _setResultsName(self, name, listAllMatches=False):
+        if __diag__.warn_name_set_on_empty_Forward:
+            if self.expr is None:
+                warnings.warn("{0}: setting results name {0!r} on {1} expression "
+                              "that has no contained expression".format("warn_name_set_on_empty_Forward",
+                                                                        name,
+                                                                        type(self).__name__),
+                              stacklevel=3)
+
+        return super(Forward, self)._setResultsName(name, listAllMatches)
+
+class TokenConverter(ParseElementEnhance):
+    """
+    Abstract subclass of :class:`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
+    ``'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 :class:`ZeroOrMore` and :class:`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 :class:`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 :class:`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
+    ``">> entering method-name(line:<current_source_line>, <parse_location>, <matched_tokens>)"``.
+    When the parse action completes, the decorator will print
+    ``"<<"`` 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 ``combine=True`` in the constructor. If
+    ``combine`` is set to ``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 ``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 ``"1:1"``, but not ``"1:2"``.  Because this
+    matches a previous literal, will also match the leading
+    ``"1:1"`` in ``"1:10"``. If this is not desired, use
+    :class:`matchPreviousExpr`. Do *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 ``"1:1"``, but not ``"1:2"``.  Because this
+    matches by expressions, will *not* match the leading ``"1:1"``
+    in ``"1:10"``; the expressions are evaluated first, and then
+    compared, so ``"1"`` is compared with ``"10"``. Do *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, asKeyword=False):
+    """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 :class:`MatchFirst` for best performance.
+
+    Parameters:
+
+     - strs - a string of space-delimited literals, or a collection of
+       string literals
+     - caseless - (default= ``False``) - treat all literals as
+       caseless
+     - useRegex - (default= ``True``) - as an optimization, will
+       generate a Regex object; otherwise, will generate
+       a :class:`MatchFirst` object (if ``caseless=True`` or ``asKeyword=True``, or if
+       creating a :class:`Regex` raises an exception)
+     - asKeyword - (default=``False``) - enforce Keyword-style matching on the
+       generated expressions
+
+    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 isinstance(caseless, basestring):
+        warnings.warn("More than one string argument passed to oneOf, pass "
+                      "choices as a list or space-delimited string", stacklevel=2)
+
+    if caseless:
+        isequal = (lambda a, b: a.upper() == b.upper())
+        masks = (lambda a, b: b.upper().startswith(a.upper()))
+        parseElementClass = CaselessKeyword if asKeyword else CaselessLiteral
+    else:
+        isequal = (lambda a, b: a == b)
+        masks = (lambda a, b: b.startswith(a))
+        parseElementClass = Keyword if asKeyword else 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()
+
+    if not asKeyword:
+        # if not producing keywords, need to reorder to take care to avoid masking
+        # longer choices with shorter ones
+        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)
+                    break
+            else:
+                i += 1
+
+    if not (caseless or asKeyword) 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 :class:`Dict`, :class:`ZeroOrMore`, and
+    :class:`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 :class:`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(OneOrMore(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 ``asString`` argument is passed as
+    ``False``, then the return value is
+    a :class:`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
+    :class:`originalTextFor` contains expressions with defined
+    results names, you must set ``asString`` to ``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).addParseAction(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 ``<TAB>`` characters, you
+    may want to call :class:`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 ``\-``
+       or ``\]``)
+     - an escaped hex character with a leading ``'\x'``
+       (``\x21``, which is a ``'!'`` character) (``\0x##``
+       is also supported for backwards compatibility)
+     - an escaped octal character with a leading ``'\0'``
+       (``\041``, which is a ``'!'`` character)
+     - a range of any of the above, separated by a dash (``'a-z'``,
+       etc.)
+     - any combination of the above (``'aeiouy'``,
+       ``'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
+    :class:`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
+    ``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 :class:`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 :class:`pyparsing_common.upcaseTokens`"""
+
+downcaseTokens = tokenMap(lambda t: _ustr(t).lower())
+"""(Deprecated) Helper parse action to convert tokens to lower case.
+Deprecated in favor of :class:`pyparsing_common.downcaseTokens`"""
+
+def _makeTags(tagStr, xml,
+              suppress_LT=Suppress("<"),
+              suppress_GT=Suppress(">")):
+    """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_LT
+                   + tagStr("tag")
+                   + Dict(ZeroOrMore(Group(tagAttrName + Suppress("=") + tagAttrValue)))
+                   + Optional("/", default=[False])("empty").setParseAction(lambda s, l, t: t[0] == '/')
+                   + suppress_GT)
+    else:
+        tagAttrValue = quotedString.copy().setParseAction(removeQuotes) | Word(printables, excludeChars=">")
+        openTag = (suppress_LT
+                   + tagStr("tag")
+                   + Dict(ZeroOrMore(Group(tagAttrName.setParseAction(downcaseTokens)
+                                           + Optional(Suppress("=") + tagAttrValue))))
+                   + Optional("/", default=[False])("empty").setParseAction(lambda s, l, t: t[0] == '/')
+                   + suppress_GT)
+    closeTag = Combine(_L("</") + tagStr + ">", adjacent=False)
+
+    openTag.setName("<%s>" % resname)
+    # add start<tagname> results name in parse action now that ungrouped names are not reported at two levels
+    openTag.addParseAction(lambda t: t.__setitem__("start" + "".join(resname.replace(":", " ").title().split()), t.copy()))
+    closeTag = closeTag("end" + "".join(resname.replace(":", " ").title().split())).setName("</%s>" % resname)
+    openTag.tag = resname
+    closeTag.tag = resname
+    openTag.tag_body = SkipTo(closeTag())
+    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="https://github.com/pyparsing/pyparsing/wiki">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 -> https://github.com/pyparsing/pyparsing/wiki
+    """
+    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 :class:`makeHTMLTags`
+    """
+    return _makeTags(tagStr, True)
+
+def withAttribute(*args, **attrDict):
+    """Helper to create a validating parse action to be used with start
+    tags created with :class:`makeXMLTags` or
+    :class:`makeHTMLTags`. Use ``withAttribute`` to qualify
+    a starting tag with a required attribute value, to avoid false
+    matches on common tags such as ``<TD>`` or ``<DIV>``.
+
+    Call ``withAttribute`` with a series of attribute names and
+    values. Specify the list of filter attributes names and values as:
+
+     - keyword arguments, as in ``(align="right")``, or
+     - as an explicit dict with ``**`` operator, when an attribute
+       name is also a Python reserved word, as in ``**{"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 ``class`` (with or without a namespace), use
+    :class:`withClass`.
+
+    To verify that the attribute exists, but without specifying a value,
+    pass ``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 :class:`withAttribute` when
+    matching on a div class - made difficult because ``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 = SimpleNamespace()
+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
+    :class:`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
+         ``opAssoc.RIGHT`` and ``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
+         ``setParseAction(*fn)``
+         (:class:`ParserElement.setParseAction`)
+     - lpar - expression for matching left-parentheses
+       (default= ``Suppress('(')``)
+     - rpar - expression for matching right-parentheses
+       (default= ``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]]]
+    """
+    # captive version of FollowedBy that does not do parse actions or capture results names
+    class _FB(FollowedBy):
+        def parseImpl(self, instring, loc, doActions=True):
+            self.expr.tryParse(instring, loc)
+            return loc, []
+
+    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 = _FB(lastExpr + opExpr) + Group(lastExpr + OneOrMore(opExpr))
+            elif arity == 2:
+                if opExpr is not None:
+                    matchExpr = _FB(lastExpr + opExpr + lastExpr) + Group(lastExpr + OneOrMore(opExpr + lastExpr))
+                else:
+                    matchExpr = _FB(lastExpr + lastExpr) + Group(lastExpr + OneOrMore(lastExpr))
+            elif arity == 3:
+                matchExpr = (_FB(lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr)
+                             + Group(lastExpr + OneOrMore(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 = _FB(opExpr.expr + thisExpr) + Group(opExpr + thisExpr)
+            elif arity == 2:
+                if opExpr is not None:
+                    matchExpr = _FB(lastExpr + opExpr + thisExpr) + Group(lastExpr + OneOrMore(opExpr + thisExpr))
+                else:
+                    matchExpr = _FB(lastExpr + thisExpr) + Group(lastExpr + OneOrMore(thisExpr))
+            elif arity == 3:
+                matchExpr = (_FB(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 :class:`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= ``"("``); can also be a pyparsing expression
+     - closer - closing character for a nested list
+       (default= ``")"``); can also be a pyparsing expression
+     - content - expression for items within the nested lists
+       (default= ``None``)
+     - ignoreExpr - expression for ignoring opening and closing
+       delimiters (default= :class:`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 ``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
+    :class:`Or` or :class:`MatchFirst`. The default is
+    :class:`quotedString`, but if no expressions are to be ignored, then
+    pass ``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 current level; set to False for block of left-most
+       statements (default= ``True``)
+
+    A valid block must contain at least one ``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']]]]]]]
+    """
+    backup_stack = indentStack[:]
+
+    def reset_stack():
+        indentStack[:] = backup_stack
+
+    def checkPeerIndent(s, l, t):
+        if l >= len(s): return
+        curCol = col(l, s)
+        if curCol != indentStack[-1]:
+            if curCol > indentStack[-1]:
+                raise ParseException(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 in indentStack):
+            raise ParseException(s, l, "not an unindent")
+        if curCol < indentStack[-1]:
+            indentStack.pop()
+
+    NL = OneOrMore(LineEnd().setWhitespaceChars("\t ").suppress(), stopOn=StringEnd())
+    INDENT = (Empty() + Empty().setParseAction(checkSubIndent)).setName('INDENT')
+    PEER   = Empty().setParseAction(checkPeerIndent).setName('')
+    UNDENT = Empty().setParseAction(checkUnindent).setName('UNINDENT')
+    if indent:
+        smExpr = Group(Optional(NL)
+                       + INDENT
+                       + OneOrMore(PEER + Group(blockStatementExpr) + Optional(NL), stopOn=StringEnd())
+                       + UNDENT)
+    else:
+        smExpr = Group(Optional(NL)
+                       + OneOrMore(PEER + Group(blockStatementExpr) + Optional(NL), stopOn=StringEnd())
+                       + UNDENT)
+    smExpr.setFailAction(lambda a, b, c, d: reset_stack())
+    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 ``/* ... */``"
+
+htmlComment = Regex(r"<!--[\s\S]*?-->").setName("HTML comment")
+"Comment of the form ``<!-- ... -->``"
+
+restOfLine = Regex(r".*").leaveWhitespace().setName("rest of line")
+dblSlashComment = Regex(r"//(?:\\\n|[^\n])*").setName("// comment")
+"Comment of the form ``// ... (to end of line)``"
+
+cppStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/' | dblSlashComment).setName("C++ style comment")
+"Comment of either form :class:`cStyleComment` or :class:`dblSlashComment`"
+
+javaStyleComment = cppStyleComment
+"Same as :class:`cppStyleComment`"
+
+pythonStyleComment = Regex(r"#.*").setName("Python style comment")
+"Comment of the form ``# ... (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 :class:`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 (:class:`integers<integer>`, :class:`reals<real>`,
+       :class:`scientific notation<sci_real>`)
+     - common :class:`programming identifiers<identifier>`
+     - network addresses (:class:`MAC<mac_address>`,
+       :class:`IPv4<ipv4_address>`, :class:`IPv6<ipv6_address>`)
+     - ISO8601 :class:`dates<iso8601_date>` and
+       :class:`datetime<iso8601_datetime>`
+     - :class:`UUID<uuid>`
+     - :class:`comma-separated list<comma_separated_list>`
+
+    Parse actions:
+
+     - :class:`convertToInteger`
+     - :class:`convertToFloat`
+     - :class:`convertToDate`
+     - :class:`convertToDatetime`
+     - :class:`stripHTMLTags`
+     - :class:`upcaseTokens`
+     - :class:`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*|\.\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+\.\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 (``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= ``"%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= ``"%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 (``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 (``yyyy-mm-ddThh:mm:ss.s(Z|+-00:00)``) - trailing seconds, milliseconds, and timezone optional; accepts separating ``'T'`` or ``' '``"
+
+    uuid = Regex(r'[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}').setName("UUID")
+    "UUID (``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="https://github.com/pyparsing/pyparsing/wiki">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)
+
+        Prints::
+
+            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."""
+
+
+class _lazyclassproperty(object):
+    def __init__(self, fn):
+        self.fn = fn
+        self.__doc__ = fn.__doc__
+        self.__name__ = fn.__name__
+
+    def __get__(self, obj, cls):
+        if cls is None:
+            cls = type(obj)
+        if not hasattr(cls, '_intern') or any(cls._intern is getattr(superclass, '_intern', [])
+                                              for superclass in cls.__mro__[1:]):
+            cls._intern = {}
+        attrname = self.fn.__name__
+        if attrname not in cls._intern:
+            cls._intern[attrname] = self.fn(cls)
+        return cls._intern[attrname]
+
+
+class unicode_set(object):
+    """
+    A set of Unicode characters, for language-specific strings for
+    ``alphas``, ``nums``, ``alphanums``, and ``printables``.
+    A unicode_set is defined by a list of ranges in the Unicode character
+    set, in a class attribute ``_ranges``, such as::
+
+        _ranges = [(0x0020, 0x007e), (0x00a0, 0x00ff),]
+
+    A unicode set can also be defined using multiple inheritance of other unicode sets::
+
+        class CJK(Chinese, Japanese, Korean):
+            pass
+    """
+    _ranges = []
+
+    @classmethod
+    def _get_chars_for_ranges(cls):
+        ret = []
+        for cc in cls.__mro__:
+            if cc is unicode_set:
+                break
+            for rr in cc._ranges:
+                ret.extend(range(rr[0], rr[-1] + 1))
+        return [unichr(c) for c in sorted(set(ret))]
+
+    @_lazyclassproperty
+    def printables(cls):
+        "all non-whitespace characters in this range"
+        return u''.join(filterfalse(unicode.isspace, cls._get_chars_for_ranges()))
+
+    @_lazyclassproperty
+    def alphas(cls):
+        "all alphabetic characters in this range"
+        return u''.join(filter(unicode.isalpha, cls._get_chars_for_ranges()))
+
+    @_lazyclassproperty
+    def nums(cls):
+        "all numeric digit characters in this range"
+        return u''.join(filter(unicode.isdigit, cls._get_chars_for_ranges()))
+
+    @_lazyclassproperty
+    def alphanums(cls):
+        "all alphanumeric characters in this range"
+        return cls.alphas + cls.nums
+
+
+class pyparsing_unicode(unicode_set):
+    """
+    A namespace class for defining common language unicode_sets.
+    """
+    _ranges = [(32, sys.maxunicode)]
+
+    class Latin1(unicode_set):
+        "Unicode set for Latin-1 Unicode Character Range"
+        _ranges = [(0x0020, 0x007e), (0x00a0, 0x00ff),]
+
+    class LatinA(unicode_set):
+        "Unicode set for Latin-A Unicode Character Range"
+        _ranges = [(0x0100, 0x017f),]
+
+    class LatinB(unicode_set):
+        "Unicode set for Latin-B Unicode Character Range"
+        _ranges = [(0x0180, 0x024f),]
+
+    class Greek(unicode_set):
+        "Unicode set for Greek Unicode Character Ranges"
+        _ranges = [
+            (0x0370, 0x03ff), (0x1f00, 0x1f15), (0x1f18, 0x1f1d), (0x1f20, 0x1f45), (0x1f48, 0x1f4d),
+            (0x1f50, 0x1f57), (0x1f59,), (0x1f5b,), (0x1f5d,), (0x1f5f, 0x1f7d), (0x1f80, 0x1fb4), (0x1fb6, 0x1fc4),
+            (0x1fc6, 0x1fd3), (0x1fd6, 0x1fdb), (0x1fdd, 0x1fef), (0x1ff2, 0x1ff4), (0x1ff6, 0x1ffe),
+        ]
+
+    class Cyrillic(unicode_set):
+        "Unicode set for Cyrillic Unicode Character Range"
+        _ranges = [(0x0400, 0x04ff)]
+
+    class Chinese(unicode_set):
+        "Unicode set for Chinese Unicode Character Range"
+        _ranges = [(0x4e00, 0x9fff), (0x3000, 0x303f),]
+
+    class Japanese(unicode_set):
+        "Unicode set for Japanese Unicode Character Range, combining Kanji, Hiragana, and Katakana ranges"
+        _ranges = []
+
+        class Kanji(unicode_set):
+            "Unicode set for Kanji Unicode Character Range"
+            _ranges = [(0x4E00, 0x9Fbf), (0x3000, 0x303f),]
+
+        class Hiragana(unicode_set):
+            "Unicode set for Hiragana Unicode Character Range"
+            _ranges = [(0x3040, 0x309f),]
+
+        class Katakana(unicode_set):
+            "Unicode set for Katakana  Unicode Character Range"
+            _ranges = [(0x30a0, 0x30ff),]
+
+    class Korean(unicode_set):
+        "Unicode set for Korean Unicode Character Range"
+        _ranges = [(0xac00, 0xd7af), (0x1100, 0x11ff), (0x3130, 0x318f), (0xa960, 0xa97f), (0xd7b0, 0xd7ff), (0x3000, 0x303f),]
+
+    class CJK(Chinese, Japanese, Korean):
+        "Unicode set for combined Chinese, Japanese, and Korean (CJK) Unicode Character Range"
+        pass
+
+    class Thai(unicode_set):
+        "Unicode set for Thai Unicode Character Range"
+        _ranges = [(0x0e01, 0x0e3a), (0x0e3f, 0x0e5b),]
+
+    class Arabic(unicode_set):
+        "Unicode set for Arabic Unicode Character Range"
+        _ranges = [(0x0600, 0x061b), (0x061e, 0x06ff), (0x0700, 0x077f),]
+
+    class Hebrew(unicode_set):
+        "Unicode set for Hebrew Unicode Character Range"
+        _ranges = [(0x0590, 0x05ff),]
+
+    class Devanagari(unicode_set):
+        "Unicode set for Devanagari Unicode Character Range"
+        _ranges = [(0x0900, 0x097f), (0xa8e0, 0xa8ff)]
+
+pyparsing_unicode.Japanese._ranges = (pyparsing_unicode.Japanese.Kanji._ranges
+                                      + pyparsing_unicode.Japanese.Hiragana._ranges
+                                      + pyparsing_unicode.Japanese.Katakana._ranges)
+
+# define ranges in language character sets
+if PY_3:
+    setattr(pyparsing_unicode, u"العربية", pyparsing_unicode.Arabic)
+    setattr(pyparsing_unicode, u"中文", pyparsing_unicode.Chinese)
+    setattr(pyparsing_unicode, u"кириллица", pyparsing_unicode.Cyrillic)
+    setattr(pyparsing_unicode, u"Ελληνικά", pyparsing_unicode.Greek)
+    setattr(pyparsing_unicode, u"עִברִית", pyparsing_unicode.Hebrew)
+    setattr(pyparsing_unicode, u"日本語", pyparsing_unicode.Japanese)
+    setattr(pyparsing_unicode.Japanese, u"漢字", pyparsing_unicode.Japanese.Kanji)
+    setattr(pyparsing_unicode.Japanese, u"カタカナ", pyparsing_unicode.Japanese.Katakana)
+    setattr(pyparsing_unicode.Japanese, u"ひらがな", pyparsing_unicode.Japanese.Hiragana)
+    setattr(pyparsing_unicode, u"한국어", pyparsing_unicode.Korean)
+    setattr(pyparsing_unicode, u"ไทย", pyparsing_unicode.Thai)
+    setattr(pyparsing_unicode, u"देवनागरी", pyparsing_unicode.Devanagari)
+
+
+class pyparsing_test:
+    """
+    namespace class for classes useful in writing unit tests
+    """
+
+    class reset_pyparsing_context:
+        """
+        Context manager to be used when writing unit tests that modify pyparsing config values:
+         - packrat parsing
+         - default whitespace characters.
+         - default keyword characters
+         - literal string auto-conversion class
+         - __diag__ settings
+
+        Example:
+            with reset_pyparsing_context():
+                # test that literals used to construct a grammar are automatically suppressed
+                ParserElement.inlineLiteralsUsing(Suppress)
+
+                term = Word(alphas) | Word(nums)
+                group = Group('(' + term[...] + ')')
+
+                # assert that the '()' characters are not included in the parsed tokens
+                self.assertParseAndCheckLisst(group, "(abc 123 def)", ['abc', '123', 'def'])
+
+            # after exiting context manager, literals are converted to Literal expressions again
+        """
+
+        def __init__(self):
+            self._save_context = {}
+
+        def save(self):
+            self._save_context["default_whitespace"] = ParserElement.DEFAULT_WHITE_CHARS
+            self._save_context["default_keyword_chars"] = Keyword.DEFAULT_KEYWORD_CHARS
+            self._save_context[
+                "literal_string_class"
+            ] = ParserElement._literalStringClass
+            self._save_context["packrat_enabled"] = ParserElement._packratEnabled
+            self._save_context["packrat_parse"] = ParserElement._parse
+            self._save_context["__diag__"] = {
+                name: getattr(__diag__, name) for name in __diag__._all_names
+            }
+            self._save_context["__compat__"] = {
+                "collect_all_And_tokens": __compat__.collect_all_And_tokens
+            }
+            return self
+
+        def restore(self):
+            # reset pyparsing global state
+            if (
+                ParserElement.DEFAULT_WHITE_CHARS
+                != self._save_context["default_whitespace"]
+            ):
+                ParserElement.setDefaultWhitespaceChars(
+                    self._save_context["default_whitespace"]
+                )
+            Keyword.DEFAULT_KEYWORD_CHARS = self._save_context["default_keyword_chars"]
+            ParserElement.inlineLiteralsUsing(
+                self._save_context["literal_string_class"]
+            )
+            for name, value in self._save_context["__diag__"].items():
+                setattr(__diag__, name, value)
+            ParserElement._packratEnabled = self._save_context["packrat_enabled"]
+            ParserElement._parse = self._save_context["packrat_parse"]
+            __compat__.collect_all_And_tokens = self._save_context["__compat__"]
+
+        def __enter__(self):
+            return self.save()
+
+        def __exit__(self, *args):
+            return self.restore()
+
+    class TestParseResultsAsserts:
+        """
+        A mixin class to add parse results assertion methods to normal unittest.TestCase classes.
+        """
+        def assertParseResultsEquals(
+            self, result, expected_list=None, expected_dict=None, msg=None
+        ):
+            """
+            Unit test assertion to compare a ParseResults object with an optional expected_list,
+            and compare any defined results names with an optional expected_dict.
+            """
+            if expected_list is not None:
+                self.assertEqual(expected_list, result.asList(), msg=msg)
+            if expected_dict is not None:
+                self.assertEqual(expected_dict, result.asDict(), msg=msg)
+
+        def assertParseAndCheckList(
+            self, expr, test_string, expected_list, msg=None, verbose=True
+        ):
+            """
+            Convenience wrapper assert to test a parser element and input string, and assert that
+            the resulting ParseResults.asList() is equal to the expected_list.
+            """
+            result = expr.parseString(test_string, parseAll=True)
+            if verbose:
+                print(result.dump())
+            self.assertParseResultsEquals(result, expected_list=expected_list, msg=msg)
+
+        def assertParseAndCheckDict(
+            self, expr, test_string, expected_dict, msg=None, verbose=True
+        ):
+            """
+            Convenience wrapper assert to test a parser element and input string, and assert that
+            the resulting ParseResults.asDict() is equal to the expected_dict.
+            """
+            result = expr.parseString(test_string, parseAll=True)
+            if verbose:
+                print(result.dump())
+            self.assertParseResultsEquals(result, expected_dict=expected_dict, msg=msg)
+
+        def assertRunTestResults(
+            self, run_tests_report, expected_parse_results=None, msg=None
+        ):
+            """
+            Unit test assertion to evaluate output of ParserElement.runTests(). If a list of
+            list-dict tuples is given as the expected_parse_results argument, then these are zipped
+            with the report tuples returned by runTests and evaluated using assertParseResultsEquals.
+            Finally, asserts that the overall runTests() success value is True.
+
+            :param run_tests_report: tuple(bool, [tuple(str, ParseResults or Exception)]) returned from runTests
+            :param expected_parse_results (optional): [tuple(str, list, dict, Exception)]
+            """
+            run_test_success, run_test_results = run_tests_report
+
+            if expected_parse_results is not None:
+                merged = [
+                    (rpt[0], rpt[1], expected)
+                    for rpt, expected in zip(run_test_results, expected_parse_results)
+                ]
+                for test_string, result, expected in merged:
+                    # expected should be a tuple containing a list and/or a dict or an exception,
+                    # and optional failure message string
+                    # an empty tuple will skip any result validation
+                    fail_msg = next(
+                        (exp for exp in expected if isinstance(exp, str)), None
+                    )
+                    expected_exception = next(
+                        (
+                            exp
+                            for exp in expected
+                            if isinstance(exp, type) and issubclass(exp, Exception)
+                        ),
+                        None,
+                    )
+                    if expected_exception is not None:
+                        with self.assertRaises(
+                            expected_exception=expected_exception, msg=fail_msg or msg
+                        ):
+                            if isinstance(result, Exception):
+                                raise result
+                    else:
+                        expected_list = next(
+                            (exp for exp in expected if isinstance(exp, list)), None
+                        )
+                        expected_dict = next(
+                            (exp for exp in expected if isinstance(exp, dict)), None
+                        )
+                        if (expected_list, expected_dict) != (None, None):
+                            self.assertParseResultsEquals(
+                                result,
+                                expected_list=expected_list,
+                                expected_dict=expected_dict,
+                                msg=fail_msg or msg,
+                            )
+                        else:
+                            # warning here maybe?
+                            print("no validation for {!r}".format(test_string))
+
+            # do this last, in case some specific test results can be reported instead
+            self.assertTrue(
+                run_test_success, msg=msg if msg is not None else "failed runTests"
+            )
+
+        @contextmanager
+        def assertRaisesParseException(self, exc_type=ParseException, msg=None):
+            with self.assertRaises(exc_type, msg=msg):
+                yield
+
+
+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
+        """)