text: #
  # core.py
  #
  from abc import ABC, abstractmethod
  import string
  import copy
  import warnings
  import re
  import sre_constants
  from collections.abc import Iterable
  import traceback
  import types
  from operator import itemgetter
  from functools import wraps
  from threading import RLock
  
  from .util import (
      _FifoCache,
      _UnboundedCache,
      __config_flags,
      _collapseStringToRanges,
      _escapeRegexRangeChars,
      _bslash,
      _flatten,
  )
  from .exceptions import *
  from .actions import *
  from .results import ParseResults, _ParseResultsWithOffset
  
  _MAX_INT = sys.maxsize
  str_type = (str, bytes)
  
  #
  # 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.
  #
  
  
  class __compat__(__config_flags):
      """
      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 :class:`And` expression is nested within an :class:`Or` or :class:`MatchFirst`;
         maintained for compatibility, but setting to ``False`` no longer restores pre-2.3.1
         behavior
      """
  
      _type_desc = "compatibility"
  
      collect_all_And_tokens = True
  
      _all_names = [__ for __ in locals() if not __.startswith("_")]
      _fixed_names = """
          collect_all_And_tokens
          """.split()
  
  
  class __diag__(__config_flags):
      """
      Diagnostic configuration (all default to ``False``)
       - ``warn_multiple_tokens_in_named_alternation`` - flag to enable warnings when a results
         name is defined on a :class:`MatchFirst` or :class:`Or` expression with one or more :class:`And` subexpressions
       - ``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 when a :class:`Forward` is defined
         with a results name, but has no contents defined
       - ``warn_on_parse_using_empty_Forward`` - flag to enable warnings when a :class:`Forward` is
         defined in a grammar but has never had an expression attached to it
       - ``warn_on_assignment_to_Forward`` - flag to enable warnings when a :class:`Forward` is defined
         but is overwritten by assigning using ``'='`` instead of ``'<<='`` or ``'<<'``
       - ``warn_on_multiple_string_args_to_oneof`` - flag to enable warnings when :class:`oneOf` is
         incorrectly called with multiple str arguments
       - ``enable_debug_on_named_expressions`` - flag to auto-enable debug on all subsequent
         calls to :class:`ParserElement.setName`
      """
  
      _type_desc = "diagnostic"
  
      warn_multiple_tokens_in_named_alternation = False
      warn_ungrouped_named_tokens_in_collection = False
      warn_name_set_on_empty_Forward = False
      warn_on_parse_using_empty_Forward = False
      warn_on_assignment_to_Forward = False
      warn_on_multiple_string_args_to_oneof = False
      warn_on_match_first_with_lshift_operator = False
      enable_debug_on_named_expressions = False
  
      _all_names = [__ for __ in locals() if not __.startswith("_")]
      _warning_names = [name for name in _all_names if name.startswith("warn")]
      _debug_names = [name for name in _all_names if name.startswith("enable_debug")]
  
      @classmethod
      def enable_all_warnings(cls):
          for name in cls._warning_names:
              cls.enable(name)
  
  
  # hide abstract class
  del __config_flags
  
  # 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]
  
  _generatorType = types.GeneratorType
  
  alphas = string.ascii_uppercase + string.ascii_lowercase
  nums = "0123456789"
  hexnums = nums + "ABCDEFabcdef"
  alphanums = alphas + nums
  printables = "".join(c for c in string.printable if c not in string.whitespace)
  
  _trim_arity_call_line = None
  
  
  def _trim_arity(func, maxargs=2):
      """decorator to trim function calls to match the arity of the target"""
      global _trim_arity_call_line
  
      if func in singleArgBuiltins:
          return lambda s, l, t: func(t)
  
      limit = 0
      found_arity = False
  
      def extract_tb(tb, limit=0):
          frames = traceback.extract_tb(tb, limit=limit)
          frame_summary = frames[-1]
          return [frame_summary[:2]]
  
      # 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 = 11
      # 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!!!!
      _trim_arity_call_line = (
          _trim_arity_call_line or traceback.extract_stack(limit=2)[-1]
      )
      pa_call_line_synth = (
          _trim_arity_call_line[0],
          _trim_arity_call_line[1] + LINE_DIFF,
      )
  
      def wrapper(*args):
          nonlocal found_arity, limit
          while 1:
              try:
                  ret = func(*args[limit:])
                  found_arity = True
                  return ret
              except TypeError as te:
                  # re-raise TypeErrors if they did not come from our arity testing
                  if found_arity:
                      raise
                  else:
                      tb = te.__traceback__
                      trim_arity_type_error = (
                          extract_tb(tb, limit=2)[-1][:2] == pa_call_line_synth
                      )
                      del tb
  
                      if trim_arity_type_error:
                          if limit <= maxargs:
                              limit += 1
                              continue
  
                      raise
  
      # copy func name to wrapper for sensible debug output
      # (can't use functools.wraps, since that messes with function signature)
      func_name = getattr(func, "__name__", getattr(func, "__class__").__name__)
      wrapper.__name__ = func_name
  
      return wrapper
  
  
  def conditionAsParseAction(fn, message=None, fatal=False):
      """
      Function to convert a simple predicate function that returns ``True`` or ``False``
      into a parse action. Can be used in places when a parse action is required
      and :class:`ParserElement.addCondition` cannot be used (such as when adding a condition
      to an operator level in :class:`infixNotation`).
  
      Optional keyword arguments:
  
      - ``message`` - define a custom message to be used in the raised exception
      - ``fatal`` - if True, will raise :class:`ParseFatalException` to stop parsing immediately;
        otherwise will raise :class:`ParseException`
  
      """
      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
  
  
  def _defaultStartDebugAction(instring, loc, expr):
      print(
          (
              "Match {} at loc {}({},{})".format(
                  expr, loc, lineno(loc, instring), col(loc, instring)
              )
          )
      )
  
  
  def _defaultSuccessDebugAction(instring, startloc, endloc, expr, toks):
      print("Matched " + str(expr) + " -> " + str(toks.asList()))
  
  
  def _defaultExceptionDebugAction(instring, loc, expr, exc):
      print("Exception raised:" + str(exc))
  
  
  def nullDebugAction(*args):
      """'Do-nothing' debug action, to suppress debugging output during parsing."""
  
  
  class ParserElement(ABC):
      """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
  
          # update whitespace all parse expressions defined in this module
          for expr in _builtin_exprs:
              if expr.copyDefaultWhiteChars:
                  expr.whiteChars = chars
  
      @staticmethod
      def inlineLiteralsUsing(cls):
          """
          Set class to be used for inclusion of string literals into a parser.
  
          Example::
  
              # default literal class used is Literal
              integer = Word(nums)
              date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
  
              date_str.parseString("1999/12/31")  # -> ['1999', '/', '12', '/', '31']
  
  
              # change to Suppress
              ParserElement.inlineLiteralsUsing(Suppress)
              date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
  
              date_str.parseString("1999/12/31")  # -> ['1999', '12', '31']
          """
          ParserElement._literalStringClass = cls
  
      def __init__(self, savelist=False):
          self.parseAction = list()
          self.failAction = None
          self.customName = None
          self._defaultName = None
          self.resultsName = None
          self.saveAsList = savelist
          self.skipWhitespace = True
          self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
          self.copyDefaultWhiteChars = True
          # used when checking for left-recursion
          self.mayReturnEmpty = False
          self.keepTabs = False
          self.ignoreExprs = list()
          self.debug = False
          self.streamlined = False
          # optimize exception handling for subclasses that don't advance parse index
          self.mayIndexError = True
          self.errmsg = ""
          # mark results names as modal (report only last) or cumulative (list all)
          self.modalResults = True
          # custom debug actions
          self.debugActions = (None, None, None)
          self.re = None
          # avoid redundant calls to preParse
          self.callPreparse = True
          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 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
          - callDuringTry = boolean to indicate if this method should be called during internal tryParse calls,
            default=False
  
          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 {} at loc {}({}, {})".format(self, loc, 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, raise_fatal=False):
          try:
              return self._parse(instring, loc, doActions=False)[0]
          except ParseFatalException:
              if raise_fatal:
                  raise
              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
  
      # 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::
  
                 import pyparsing
                 pyparsing.ParserElement.enablePackrat()
          """
          if not ParserElement._packratEnabled:
              ParserElement._packratEnabled = True
              if cache_size_limit is None:
                  ParserElement.packrat_cache = _UnboundedCache()
              else:
                  ParserElement.packrat_cache = _FifoCache(cache_size_limit)
              ParserElement._parse = ParserElement._parseCache
  
      def parseString(self, instring, parseAll=False):
          """
          Parse a string with respect to the parser definition. This function is intended as the primary interface to the
          client code.
  
          :param instring: The input string to be parsed.
          :param parseAll: If set, the entire input string must match the grammar.
          :raises ParseException: Raised if ``parseAll`` is set and the input string does not match the whole grammar.
          :returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
            an object with attributes if the given parser includes results names.
  
          If the input string is required to match the entire grammar, ``parseAll`` flag must be set to ``True``. This
          is also equivalent to ending the grammar with :class:`StringEnd`().
  
          To report proper column numbers, ``parseString`` operates on a copy of the input string where all tabs are
          converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
          contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
          being parsed, one can ensure a consistent view of the input string by doing one of the following:
  
          - 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, or
          - explicitly expand the tabs in your input string before calling ``parseString``.
  
          Examples:
  
          By default, partial matches are OK.
  
          >>> res = Word('a').parseString('aaaaabaaa')
          >>> print(res)
          ['aaaaa']
  
          The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
          directly to see more examples.
  
          It raises an exception if parseAll flag is set and instring does not match the whole grammar.
  
          >>> res = Word('a').parseString('aaaaabaaa', parseAll=True)
          Traceback (most recent call last):
          ...
          pyparsing.ParseException: Expected end of text, found 'b'  (at char 5), (line:1, col:6)
          """
  
          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
                  raise exc.with_traceback(None)
          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 = str(instring).expandtabs()
          instrlen = len(instring)
          loc = 0
          preparseFn = self.preParse
          parseFn = self._parse
          ParserElement.resetCache()
          matches = 0
          try:
              while loc <= instrlen and matches < maxMatches:
                  try:
                      preloc = preparseFn(instring, loc)
                      nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
                  except ParseException:
                      loc = preloc + 1
                  else:
                      if nextLoc > loc:
                          matches += 1
                          yield tokens, preloc, nextLoc
                          if overlap:
                              nextloc = preparseFn(instring, loc)
                              if nextloc > loc:
                                  loc = nextLoc
                              else:
                                  loc += 1
                          else:
                              loc = nextLoc
                      else:
                          loc = preloc + 1
          except ParseBaseException as exc:
              if ParserElement.verbose_stacktrace:
                  raise
              else:
                  # catch and re-raise exception from here, clears out pyparsing internal stack trace
                  raise exc.with_traceback(None)
  
      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, Iterable) and not isinstance(t, str_type):
                          out += list(t)
                      else:
                          out.append(t)
                  lastE = e
              out.append(instring[lastE:])
              out = [o for o in out if o]
              return "".join(map(str, _flatten(out)))
          except ParseBaseException as exc:
              if ParserElement.verbose_stacktrace:
                  raise
              else:
                  # catch and re-raise exception from here, clears out pyparsing internal stack trace
                  raise exc.with_traceback(None)
  
      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, clears out pyparsing internal stack trace
                  raise exc.with_traceback(None)
  
      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 :class:`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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  SyntaxWarning,
                  stacklevel=2,
              )
              return None
          return other + self
  
      def __sub__(self, other):
          """
          Implementation of ``-`` operator, returns :class:`And` with error stop
          """
          if isinstance(other, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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 be 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 ({}) objects".format(
                          ",".join(type(item).__name__ for item in other)
                      )
                  )
          else:
              raise TypeError(
                  "cannot multiply ParserElement and {} objects".format(
                      type(other).__name__
                  )
              )
  
          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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  SyntaxWarning,
                  stacklevel=2,
              )
              return None
          return other | self
  
      def __xor__(self, other):
          """
          Implementation of ``^`` operator - returns :class:`Or`
          """
          if isinstance(other, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  SyntaxWarning,
                  stacklevel=2,
              )
              return None
          return other ^ self
  
      def __and__(self, other):
          """
          Implementation of ``&`` operator - returns :class:`Each`
          """
          if isinstance(other, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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, str_type):
              other = self._literalStringClass(other)
          if not isinstance(other, ParserElement):
              warnings.warn(
                  "Cannot combine element of type {} with ParserElement".format(
                      type(other).__name__
                  ),
                  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("{} object is not iterable".format(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_type):
                  key = (key,)
              iter(key)
          except TypeError:
              key = (key, key)
  
          if len(key) > 2:
              warnings.warn(
                  "only 1 or 2 index arguments supported ({}{})".format(
                      key[:5], "... [{}]".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 ignoreWhitespace(self, recursive=True):
          """
          Enables the skipping of whitespace before matching the characters in the
          :class:`ParserElement`'s defined pattern.
  
          :param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
          """
          self.skipWhitespace = True
          return self
  
      def leaveWhitespace(self, recursive=True):
          """
          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.
  
          :param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
          """
          self.skipWhitespace = False
          return self
  
      def setWhitespaceChars(self, chars, copy_defaults=False):
          """
          Overrides the default whitespace chars
          """
          self.skipWhitespace = True
          self.whiteChars = chars
          self.copyDefaultWhiteChars = copy_defaults
          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, str_type):
              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):
          """
          Customize display of debugging messages while doing pattern matching::
  
           - ``startAction`` - method to be called when an expression is about to be parsed;
             should have the signature ``fn(input_string, location, expression)``
           - ``successAction`` - method to be called when an expression has successfully parsed;
             should have the signature ``fn(input_string, start_location, end_location, expression, parsed_tokens)``
           - ``exceptionAction`` - method to be called when expression fails to parse;
             should have the signature ``fn(input_string, location, expression, exception)``
          """
          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:(A-Za-z)"``.
          """
          if flag:
              self.setDebugActions(
                  _defaultStartDebugAction,
                  _defaultSuccessDebugAction,
                  _defaultExceptionDebugAction,
              )
          else:
              self.debug = False
          return self
  
      @property
      def defaultName(self):
          if self._defaultName is None:
              self._defaultName = self._generateDefaultName()
          return self._defaultName
  
      @abstractmethod
      def _generateDefaultName(self):
          """
          Child classes must define this method, which defines how the ``defaultName`` is set.
          """
  
      def setName(self, name):
          """
          Define name for this expression, makes debugging and exception messages clearer.
          Example::
              Word(nums).parseString("ABC")  # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
              Word(nums).setName("integer").parseString("ABC")  # -> Exception: Expected integer (at char 0), (line:1, col:1)
          """
          self.customName = name
          self.errmsg = "Expected " + self.name
          if __diag__.enable_debug_on_named_expressions:
              self.setDebug()
          return self
  
      @property
      def name(self):
          # This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
          return self.customName if self.customName is not None else self.defaultName
  
      def __str__(self):
          return self.name
  
      def __repr__(self):
          return str(self)
  
      def streamline(self):
          self.streamlined = True
          self._defaultName = None
          return self
  
      def recurse(self):
          return []
  
      def _checkRecursion(self, parseElementList):
          subRecCheckList = parseElementList[:] + [self]
          for e in self.recurse():
              e._checkRecursion(subRecCheckList)
  
      def validate(self, validateTrace=None):
          """
          Check defined expressions for valid structure, check for infinite recursive definitions.
          """
          self._checkRecursion([])
  
      def parseFile(self, file_or_filename, encoding="utf-8", 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", encoding=encoding) as f:
                  file_contents = f.read()
          try:
              return self.parseString(file_contents, parseAll)
          except ParseBaseException as exc:
              if ParserElement.verbose_stacktrace:
                  raise
              else:
                  # catch and re-raise exception from here, clears out pyparsing internal stack trace
                  raise exc.with_traceback(None)
  
      def __eq__(self, other):
          if self is other:
              return True
          elif isinstance(other, str_type):
              return self.matches(other)
          elif isinstance(other, ParserElement):
              return vars(self) == vars(other)
          return False
  
      def __hash__(self):
          return id(self)
  
      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(str(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, str_type):
              tests = list(map(type(tests).strip, tests.rstrip().splitlines()))
          if isinstance(comment, str_type):
              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 = "\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(
                              "{} failed: {}: {}".format(
                                  postParse.__name__, type(e).__name__, e
                              )
                          )
                  else:
                      out.append(result.dump(full=fullDump))
                  out.append("")
  
              if printResults:
                  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().__init__()
          self.anchor = expr
          self.must_skip = must_skip
  
      def _generateDefaultName(self):
          return str(self.anchor + Empty()).replace("Empty", "...")
  
      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.defaultName
  
      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().__init__(savelist=False)
  
      def _generateDefaultName(self):
          return type(self).__name__
  
  
  class Empty(Token):
      """An empty token, will always match.
      """
  
      def __init__(self):
          super().__init__()
          self.mayReturnEmpty = True
          self.mayIndexError = False
  
  
  class NoMatch(Token):
      """A token that will never match.
      """
  
      def __init__(self):
          super().__init__()
          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().__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.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 _generateDefaultName(self):
          return repr(self.match)
  
      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)
  
  
  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().__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.errmsg = "Expected {} {}".format(type(self).__name__, 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 _generateDefaultName(self):
          return repr(self.match)
  
      def parseImpl(self, instring, loc, doActions=True):
          errmsg = self.errmsg
          errloc = loc
          if self.caseless:
              if instring[loc : loc + self.matchLen].upper() == self.caselessmatch:
                  if loc == 0 or instring[loc - 1].upper() not in self.identChars:
                      if (
                          loc >= len(instring) - self.matchLen
                          or instring[loc + self.matchLen].upper() not in self.identChars
                      ):
                          return loc + self.matchLen, self.match
                      else:
                          # followed by keyword char
                          errmsg += ", was immediately followed by keyword character"
                          errloc = loc + self.matchLen
                  else:
                      # preceded by keyword char
                      errmsg += ", keyword was immediately preceded by keyword character"
                      errloc = loc - 1
              # else no match just raise plain exception
  
          else:
              if (
                  instring[loc] == self.firstMatchChar
                  and self.matchLen == 1
                  or instring.startswith(self.match, loc)
              ):
                  if loc == 0 or instring[loc - 1] not in self.identChars:
                      if (
                          loc >= len(instring) - self.matchLen
                          or instring[loc + self.matchLen] not in self.identChars
                      ):
                          return loc + self.matchLen, self.match
                      else:
                          # followed by keyword char
                          errmsg += (
                              ", keyword was immediately followed by keyword character"
                          )
                          errloc = loc + self.matchLen
                  else:
                      # preceded by keyword char
                      errmsg += ", keyword was immediately preceded by keyword character"
                      errloc = loc - 1
              # else no match just raise plain exception
  
          raise ParseException(instring, errloc, errmsg, self)
  
      @staticmethod
      def setDefaultKeywordChars(chars):
          """Overrides the default characters used by :class:`Keyword` expressions.
          """
          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().__init__(matchString.upper())
          # Preserve the defining literal.
          self.returnString = matchString
          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().__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().__init__()
          self.match_string = match_string
          self.maxMismatches = maxMismatches
          self.errmsg = "Expected {!r} (with up to {} mismatches)".format(
              self.match_string, self.maxMismatches
          )
          self.mayIndexError = False
          self.mayReturnEmpty = False
  
      def _generateDefaultName(self):
          return "{}:{!r}".format(type(self).__name__, self.match_string_)
  
      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 = start + 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.
      Parameters:
       - ``initChars`` - string of all characters that should be used to
         match as a word; "ABC" will match "AAA", "ABAB", "CBAC", etc.;
         if ``bodyChars`` is also specified, then this is the string of
         initial characters
       - ``bodyChars`` - string of characters that
         can be used for matching after a matched initial character as
         given in ``initChars``; if omitted, same as the initial characters
         (default=``None``)
       - ``min`` - minimum number of characters to match (default=1)
       - ``max`` - maximum number of characters to match (default=0)
       - ``exact`` - exact number of characters to match (default=0)
       - ``asKeyword`` - match as a keyword (default=``False``)
       - ``excludeChars`` - characters that might be
         found in the input ``bodyChars`` string but which should not be
         accepted for matching ;useful to define a word of all
         printables except for one or two characters, for instance
         (default=``None``)
  
      :class:`srange` is useful for defining custom character set strings
      for defining :class:`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().__init__()
          if not initChars:
              raise ValueError(
                  "invalid {}, initChars cannot be empty string".format(
                      type(self).__name__
                  )
              )
  
          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.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 = "[{}]+".format(
                      _collapseStringToRanges(self.initCharsOrig)
                  )
              elif len(self.initCharsOrig) == 1:
                  self.reString = "{}[{}]*".format(
                      re.escape(self.initCharsOrig),
                      _collapseStringToRanges(self.bodyCharsOrig),
                  )
              else:
                  self.reString = "[{}][{}]*".format(
                      _collapseStringToRanges(self.initCharsOrig),
                      _collapseStringToRanges(self.bodyCharsOrig),
                  )
              if self.asKeyword:
                  self.reString = r"\b" + self.reString + r"\b"
  
              try:
                  self.re = re.compile(self.reString)
              except sre_constants.error:
                  self.re = None
              else:
                  self.re_match = self.re.match
                  self.__class__ = _WordRegex
  
      def _generateDefaultName(self):
          def charsAsStr(s):
              max_repr_len = 16
              s = _collapseStringToRanges(s, re_escape=False)
              if len(s) > max_repr_len:
                  return s[: max_repr_len - 3] + "..."
              else:
                  return s
  
          if self.initCharsOrig != self.bodyCharsOrig:
              base = "W:({}, {})".format(
                  charsAsStr(self.initCharsOrig), charsAsStr(self.bodyCharsOrig)
              )
          else:
              base = "W:({})".format(charsAsStr(self.initCharsOrig))
  
          # add length specification
          if self.minLen > 1 or self.maxLen != _MAX_INT:
              if self.minLen == self.maxLen:
                  if self.minLen == 1:
                      return base[2:]
                  else:
                      return base + "{{{}}}".format(self.minLen)
              elif self.maxLen == _MAX_INT:
                  return base + "{{{},...}}".format(self.minLen)
              else:
                  return base + "{{{},{}}}".format(self.minLen, self.maxLen)
          return base
  
      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]
  
  
  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 :class:`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().__init__(
              charset, exact=1, asKeyword=asKeyword, excludeChars=excludeChars
          )
          self.reString = "[{}]".format(_collapseStringToRanges(self.initChars))
          if asKeyword:
              self.reString = r"\b{}\b".format(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 :class:`ParseResults`.
  
      If instead of the Python stdlib ``re`` module you wish to use a different RE module
      (such as the ``regex`` module), you can do so by building your ``Regex`` object with
      a compiled RE that was compiled using ``regex``.
  
      Example::
  
          realnum = Regex(r"[+-]?\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})")
  
          # named fields in a regex will be returned as named results
          date = Regex(r'(?P<year>\d{4})-(?P<month>\d\d?)-(?P<day>\d\d?)')
  
          # the Regex class will accept re's compiled using the regex module
          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().__init__()
  
          if isinstance(pattern, str_type):
              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 ({!r}) passed to Regex".format(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.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 _generateDefaultName(self):
          return "Re:({})".format(repr(self.pattern).replace("\\\\", "\\"))
  
      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 sub(self, repl):
          r"""
          Return :class:`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 re_escape quotes, typically backslash
         (default= ``None``)
       - ``escQuote`` - special quote sequence to re_escape an embedded quote
         string (such as SQL's ``""`` to re_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().__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"{}(?:[^{}{}]".format(
                  re.escape(self.quoteChar),
                  _escapeRegexRangeChars(self.endQuoteChar[0]),
                  (escChar is not None and _escapeRegexRangeChars(escChar) or ""),
              )
          else:
              self.flags = 0
              self.pattern = r"{}(?:[^{}\n\r{}]".format(
                  re.escape(self.quoteChar),
                  _escapeRegexRangeChars(self.endQuoteChar[0]),
                  (escChar is not None and _escapeRegexRangeChars(escChar) or ""),
              )
          if len(self.endQuoteChar) > 1:
              self.pattern += (
                  "|(?:"
                  + ")|(?:".join(
                      "{}[^{}]".format(
                          re.escape(self.endQuoteChar[:i]),
                          _escapeRegexRangeChars(self.endQuoteChar[i]),
                      )
                      for i in range(len(self.endQuoteChar) - 1, 0, -1)
                  )
                  + ")"
              )
  
          if escQuote:
              self.pattern += r"|(?:{})".format(re.escape(escQuote))
          if escChar:
              self.pattern += r"|(?:{}.)".format(re.escape(escChar))
              self.escCharReplacePattern = re.escape(self.escChar) + "(.)"
          self.pattern += r")*{}".format(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 {!r} passed to Regex".format(self.pattern),
                  SyntaxWarning,
                  stacklevel=2,
              )
              raise
  
          self.errmsg = "Expected " + self.name
          self.mayIndexError = False
          self.mayReturnEmpty = True
  
      def _generateDefaultName(self):
          if self.quoteChar == self.endQuoteChar and isinstance(self.quoteChar, str_type):
              return "string enclosed in {!r}".format(self.quoteChar)
  
          return "quoted string, starting with {} ending with {}".format(
              self.quoteChar, self.endQuoteChar
          )
  
      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, str_type):
                  # 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
  
  
  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().__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.errmsg = "Expected " + self.name
          self.mayReturnEmpty = self.minLen == 0
          self.mayIndexError = False
  
      def _generateDefaultName(self):
          not_chars_str = _collapseStringToRanges(self.notChars)
          if len(not_chars_str) > 16:
              return "!W:({}...)".format(self.notChars[: 16 - 3])
          else:
              return "!W:({})".format(self.notChars)
  
      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]
  
  
  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>",
          "\u00A0": "<NBSP>",
          "\u1680": "<OGHAM_SPACE_MARK>",
          "\u180E": "<MONGOLIAN_VOWEL_SEPARATOR>",
          "\u2000": "<EN_QUAD>",
          "\u2001": "<EM_QUAD>",
          "\u2002": "<EN_SPACE>",
          "\u2003": "<EM_SPACE>",
          "\u2004": "<THREE-PER-EM_SPACE>",
          "\u2005": "<FOUR-PER-EM_SPACE>",
          "\u2006": "<SIX-PER-EM_SPACE>",
          "\u2007": "<FIGURE_SPACE>",
          "\u2008": "<PUNCTUATION_SPACE>",
          "\u2009": "<THIN_SPACE>",
          "\u200A": "<HAIR_SPACE>",
          "\u200B": "<ZERO_WIDTH_SPACE>",
          "\u202F": "<NNBSP>",
          "\u205F": "<MMSP>",
          "\u3000": "<IDEOGRAPHIC_SPACE>",
      }
  
      def __init__(self, ws=" \t\r\n", min=1, max=0, exact=0):
          super().__init__()
          self.matchWhite = ws
          self.setWhitespaceChars(
              "".join(c for c in self.whiteChars if c not in self.matchWhite),
              copy_defaults=True,
          )
          # self.leaveWhitespace()
          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 _generateDefaultName(self):
          return "".join(White.whiteStrs[c] for c in self.matchWhite)
  
      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().__init__()
          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().__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().__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().__init__()
          self.setWhitespaceChars(
              ParserElement.DEFAULT_WHITE_CHARS.replace("\n", ""), copy_defaults=False
          )
          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().__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().__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
      :class:`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().__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 :class:`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().__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().__init__(savelist)
          if isinstance(exprs, _generatorType):
              exprs = list(exprs)
  
          if isinstance(exprs, str_type):
              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, str_type) for expr in exprs):
                  exprs = (
                      self._literalStringClass(e) if isinstance(e, str_type) 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 recurse(self):
          return self.exprs[:]
  
      def append(self, other):
          self.exprs.append(other)
          self._defaultName = None
          return self
  
      def leaveWhitespace(self, recursive=True):
          """
          Extends ``leaveWhitespace`` defined in base class, and also invokes ``leaveWhitespace`` on
             all contained expressions.
          """
          super().leaveWhitespace(recursive)
  
          if recursive:
              self.exprs = [e.copy() for e in self.exprs]
              for e in self.exprs:
                  e.leaveWhitespace(recursive)
          return self
  
      def ignoreWhitespace(self, recursive=True):
          """
          Extends ``ignoreWhitespace`` defined in base class, and also invokes ``leaveWhitespace`` on
             all contained expressions.
          """
          super().ignoreWhitespace(recursive)
          if recursive:
              self.exprs = [e.copy() for e in self.exprs]
              for e in self.exprs:
                  e.ignoreWhitespace(recursive)
          return self
  
      def ignore(self, other):
          if isinstance(other, Suppress):
              if other not in self.ignoreExprs:
                  super().ignore(other)
                  for e in self.exprs:
                      e.ignore(self.ignoreExprs[-1])
          else:
              super().ignore(other)
              for e in self.exprs:
                  e.ignore(self.ignoreExprs[-1])
          return self
  
      def _generateDefaultName(self):
          return "{}:({})".format(self.__class__.__name__, str(self.exprs))
  
      def streamline(self):
          super().streamline()
  
          for e in self.exprs:
              e.streamline()
  
          # collapse nested :class:`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 :class:`Or`'s and :class:`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._defaultName = 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._defaultName = None
                  self.mayReturnEmpty |= other.mayReturnEmpty
                  self.mayIndexError |= other.mayIndexError
  
          self.errmsg = "Expected " + str(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().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(
                          "{}: setting results name {!r} on {} expression "
                          "collides with {!r} on contained expression".format(
                              "warn_ungrouped_named_tokens_in_collection",
                              name,
                              type(self).__name__,
                              e.resultsName,
                          ),
                          stacklevel=3,
                      )
  
          return super()._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().__init__(*args, **kwargs)
              self.leaveWhitespace()
  
          def _generateDefaultName(self):
              return "-"
  
      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().__init__(exprs, savelist)
          self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
          self.setWhitespaceChars(
              self.exprs[0].whiteChars, copy_defaults=self.exprs[0].copyDefaultWhiteChars
          )
          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().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, str_type):
              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 _generateDefaultName(self):
          return "{" + " ".join(str(e) for e in self.exprs) + "}"
  
  
  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().__init__(exprs, savelist)
          if self.exprs:
              self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
          else:
              self.mayReturnEmpty = True
  
      def streamline(self):
          super().streamline()
          self.saveAsList = any(e.saveAsList for e in self.exprs)
          return self
  
      def parseImpl(self, instring, loc, doActions=True):
          maxExcLoc = -1
          maxException = None
          matches = []
          fatals = []
          for e in self.exprs:
              try:
                  loc2 = e.tryParse(instring, loc, raise_fatal=True)
              except ParseFatalException as pfe:
                  pfe.__traceback__ = None
                  pfe.parserElement = e
                  fatals.append(pfe)
                  maxException = None
                  maxExcLoc = -1
              except ParseException as err:
                  if not fatals:
                      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 fatals:
              if len(fatals) > 1:
                  fatals.sort(key=lambda e: -e.loc)
                  if fatals[0].loc == fatals[1].loc:
                      fatals.sort(key=lambda e: (-e.loc, -len(str(e.parserElement))))
              max_fatal = fatals[0]
              raise max_fatal
  
          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, str_type):
              other = self._literalStringClass(other)
          return self.append(other)  # Or([self, other])
  
      def _generateDefaultName(self):
          return "{" + " ^ ".join(str(e) for e in self.exprs) + "}"
  
      def _setResultsName(self, name, listAllMatches=False):
          if __diag__.warn_multiple_tokens_in_named_alternation:
              if any(isinstance(e, And) for e in self.exprs):
                  warnings.warn(
                      "{}: setting results name {!r} on {} expression "
                      "will return a list of all parsed tokens in an And alternative, "
                      "in prior versions only the first token was returned".format(
                          "warn_multiple_tokens_in_named_alternation",
                          name,
                          type(self).__name__,
                      ),
                      stacklevel=3,
                  )
  
          return super()._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().__init__(exprs, savelist)
          if self.exprs:
              self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
          else:
              self.mayReturnEmpty = True
  
      def streamline(self):
          super().streamline()
          self.saveAsList = any(e.saveAsList for e in self.exprs)
          return self
  
      def parseImpl(self, instring, loc, doActions=True):
          maxExcLoc = -1
          maxException = None
          fatals = []
          for e in self.exprs:
              try:
                  ret = e._parse(instring, loc, doActions)
                  return ret
              except ParseFatalException as pfe:
                  pfe.__traceback__ = None
                  pfe.parserElement = e
                  fatals.append(pfe)
                  maxException = None
              except ParseException as err:
                  if not fatals and 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
          if fatals:
              if len(fatals) > 1:
                  fatals.sort(key=lambda e: -e.loc)
                  if fatals[0].loc == fatals[1].loc:
                      fatals.sort(key=lambda e: (-e.loc, -len(str(e.parserElement))))
              max_fatal = fatals[0]
              raise max_fatal
  
          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, str_type):
              other = self._literalStringClass(other)
          return self.append(other)  # MatchFirst([self, other])
  
      def _generateDefaultName(self):
          return "{" + " | ".join(str(e) for e in self.exprs) + "}"
  
      def _setResultsName(self, name, listAllMatches=False):
          if __diag__.warn_multiple_tokens_in_named_alternation:
              if any(isinstance(e, And) for e in self.exprs):
                  warnings.warn(
                      "{}: setting results name {!r} on {} 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()._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().__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().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
          failed = []
          fatals = []
          while keepMatching:
              tmpExprs = tmpReqd + tmpOpt + self.multioptionals + self.multirequired
              failed.clear()
              fatals.clear()
              for e in tmpExprs:
                  try:
                      tmpLoc = e.tryParse(instring, tmpLoc, raise_fatal=True)
                  except ParseFatalException as pfe:
                      pfe.__traceback__ = None
                      pfe.parserElement = e
                      fatals.append(pfe)
                      failed.append(e)
                  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
  
          # look for any ParseFatalExceptions
          if fatals:
              if len(fatals) > 1:
                  fatals.sort(key=lambda e: -e.loc)
                  if fatals[0].loc == fatals[1].loc:
                      fatals.sort(key=lambda e: (-e.loc, -len(str(e.parserElement))))
              max_fatal = fatals[0]
              raise max_fatal
  
          if tmpReqd:
              missing = ", ".join(str(e) for e in tmpReqd)
              raise ParseException(
                  instring,
                  loc,
                  "Missing one or more required elements ({})".format(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 _generateDefaultName(self):
          return "{" + " & ".join(str(e) for e in self.exprs) + "}"
  
  
  class ParseElementEnhance(ParserElement):
      """Abstract subclass of :class:`ParserElement`, for combining and
      post-processing parsed tokens.
      """
  
      def __init__(self, expr, savelist=False):
          super().__init__(savelist)
          if isinstance(expr, str_type):
              if issubclass(self._literalStringClass, Token):
                  expr = self._literalStringClass(expr)
              elif issubclass(type(self), self._literalStringClass):
                  expr = Literal(expr)
              else:
                  expr = self._literalStringClass(Literal(expr))
          self.expr = expr
          if expr is not None:
              self.mayIndexError = expr.mayIndexError
              self.mayReturnEmpty = expr.mayReturnEmpty
              self.setWhitespaceChars(
                  expr.whiteChars, copy_defaults=expr.copyDefaultWhiteChars
              )
              self.skipWhitespace = expr.skipWhitespace
              self.saveAsList = expr.saveAsList
              self.callPreparse = expr.callPreparse
              self.ignoreExprs.extend(expr.ignoreExprs)
  
      def recurse(self):
          return [self.expr] if self.expr is not None else []
  
      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, recursive=True):
          super().leaveWhitespace(recursive)
  
          if recursive:
              self.expr = self.expr.copy()
              if self.expr is not None:
                  self.expr.leaveWhitespace(recursive)
          return self
  
      def ignoreWhitespace(self, recursive=True):
          super().ignoreWhitespace(recursive)
  
          if recursive:
              self.expr = self.expr.copy()
              if self.expr is not None:
                  self.expr.ignoreWhitespace(recursive)
          return self
  
      def ignore(self, other):
          if isinstance(other, Suppress):
              if other not in self.ignoreExprs:
                  super().ignore(other)
                  if self.expr is not None:
                      self.expr.ignore(self.ignoreExprs[-1])
          else:
              super().ignore(other)
              if self.expr is not None:
                  self.expr.ignore(self.ignoreExprs[-1])
          return self
  
      def streamline(self):
          super().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 _generateDefaultName(self):
          return "{}:({})".format(self.__class__.__name__, str(self.expr))
  
  
  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().__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, :class:`Literal`,
      :class:`Keyword`, or a :class:`Word` or :class:`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().__init__(expr)
          self.expr = self.expr().leaveWhitespace()
          self.mayReturnEmpty = True
          self.mayIndexError = False
          self.exact = False
          if isinstance(expr, str_type):
              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().__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, " + str(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 _generateDefaultName(self):
          return "~{" + str(self.expr) + "}"
  
  
  class _MultipleMatch(ParseElementEnhance):
      def __init__(self, expr, stopOn=None):
          super().__init__(expr)
          self.saveAsList = True
          ender = stopOn
          if isinstance(ender, str_type):
              ender = self._literalStringClass(ender)
          self.stopOn(ender)
  
      def stopOn(self, ender):
          if isinstance(ender, str_type):
              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] + self.expr.recurse():
                  if isinstance(e, ParserElement) and e.resultsName:
                      warnings.warn(
                          "{}: setting results name {!r} on {} expression "
                          "collides with {!r} on contained expression".format(
                              "warn_ungrouped_named_tokens_in_collection",
                              name,
                              type(self).__name__,
                              e.resultsName,
                          ),
                          stacklevel=3,
                      )
  
          return super()._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 _generateDefaultName(self):
          return "{" + str(self.expr) + "}..."
  
  
  class ZeroOrMore(_MultipleMatch):
      """Optional repetition of zero or more of the given expression.
  
      Parameters:
       - ``expr`` - expression that must match zero or more times
       - ``stopOn`` - expression for a terminating sentinel
         (only required if the sentinel would ordinarily match the repetition
         expression) - (default= ``None``)
  
      Example: similar to :class:`OneOrMore`
      """
  
      def __init__(self, expr, stopOn=None):
          super().__init__(expr, stopOn=stopOn)
          self.mayReturnEmpty = True
  
      def parseImpl(self, instring, loc, doActions=True):
          try:
              return super().parseImpl(instring, loc, doActions)
          except (ParseException, IndexError):
              return loc, ParseResults([], name=self.resultsName)
  
      def _generateDefaultName(self):
          return "[" + str(self.expr) + "]..."
  
  
  class _NullToken:
      def __bool__(self):
          return False
  
      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().__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 _generateDefaultName(self):
          return "[" + str(self.expr) + "]"
  
  
  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`` - if ``True``, the target expression is also parsed
         (the skipped text and target expression are returned as a 2-element
         list) (default= ``False``).
       - ``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 :class:`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().__init__(other)
          self.ignoreExpr = ignore
          self.mayReturnEmpty = True
          self.mayIndexError = False
          self.includeMatch = include
          self.saveAsList = False
          if isinstance(failOn, str_type):
              self.failOn = self._literalStringClass(failOn)
          else:
              self.failOn = failOn
          self.errmsg = "No match found for " + str(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):
          self.caller_frame = traceback.extract_stack(limit=2)[0]
          super().__init__(other, savelist=False)
          self.lshift_line = None
  
      def __lshift__(self, other):
          if hasattr(self, "caller_frame"):
              del self.caller_frame
          if isinstance(other, str_type):
              other = self._literalStringClass(other)
          self.expr = other
          self.mayIndexError = self.expr.mayIndexError
          self.mayReturnEmpty = self.expr.mayReturnEmpty
          self.setWhitespaceChars(
              self.expr.whiteChars, copy_defaults=self.expr.copyDefaultWhiteChars
          )
          self.skipWhitespace = self.expr.skipWhitespace
          self.saveAsList = self.expr.saveAsList
          self.ignoreExprs.extend(self.expr.ignoreExprs)
          self.lshift_line = traceback.extract_stack(limit=2)[-2]
          return self
  
      def __ilshift__(self, other):
          return self << other
  
      def __or__(self, other):
          caller_line = traceback.extract_stack(limit=2)[-2]
          if (
              __diag__.warn_on_match_first_with_lshift_operator
              and caller_line == self.lshift_line
          ):
              warnings.warn(
                  "using '<<' operator with '|' is probably an error, use '<<='",
                  SyntaxWarning,
                  stacklevel=2,
              )
          ret = super().__or__(other)
          return ret
  
      def __del__(self):
          # see if we are getting dropped because of '=' reassignment of var instead of '<<=' or '<<'
          if self.expr is None and __diag__.warn_on_assignment_to_Forward:
              warnings.warn_explicit(
                  "Forward defined here but no expression attached later using '<<=' or '<<'",
                  SyntaxWarning,
                  filename=self.caller_frame.filename,
                  lineno=self.caller_frame.lineno,
              )
  
      def parseImpl(self, instring, loc, doActions=True):
          if self.expr is None and __diag__.warn_on_parse_using_empty_Forward:
              # walk stack until parseString, scanString, searchString, or transformString is found
              parse_fns = ["parseString", "scanString", "searchString", "transformString"]
              tb = traceback.extract_stack(limit=200)
              for i, frm in enumerate(reversed(tb), start=1):
                  if frm.name in parse_fns:
                      stacklevel = i + 1
                      break
              else:
                  stacklevel = 2
              warnings.warn(
                  "Forward expression was never assigned a value, will not parse any input",
                  UserWarning,
                  stacklevel=stacklevel,
              )
          return super().parseImpl(instring, loc, doActions)
  
      def leaveWhitespace(self, recursive=True):
          self.skipWhitespace = False
          return self
  
      def ignoreWhitespace(self, recursive=True):
          self.skipWhitespace = True
          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 _generateDefaultName(self):
          # Avoid infinite recursion by setting a temporary _defaultName
          self._defaultName = ": ..."
  
          # Use the string representation of main expression.
          retString = "..."
          try:
              if self.expr is not None:
                  retString = str(self.expr)[:1000]
              else:
                  retString = "None"
          finally:
              return self.__class__.__name__ + ": " + retString
  
      def copy(self):
          if self.expr is not None:
              return super().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(
                      "{}: setting results name {!r} on {} expression "
                      "that has no contained expression".format(
                          "warn_name_set_on_empty_Forward", name, type(self).__name__
                      ),
                      stacklevel=3,
                  )
  
          return super()._setResultsName(name, listAllMatches)
  
  
  class TokenConverter(ParseElementEnhance):
      """
      Abstract subclass of :class:`ParseExpression`, for converting parsed results.
      """
  
      def __init__(self, expr, savelist=False):
          super().__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().__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().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().__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().__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 = str(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:
      """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, "OnlyOnce obj called multiple times w/out reset")
  
      def reset(self):
          """Allow the associated parse action to be called once more.
          """
  
          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 {}(line: {!r}, {}, {!r})\n".format(thisFunc, line(l, s), l, t)
          )
          try:
              ret = f(*paArgs)
          except Exception as exc:
              sys.stderr.write("<<leaving {} (exception: {})\n".format(thisFunc, exc))
              raise
          sys.stderr.write("<<leaving {} (ret: {!r})\n".format(thisFunc, ret))
          return ret
  
      z.__name__ = f.__name__
      return z
  
  
  # 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"\[]-*.$+^?()~ ", exact=2).setParseAction(
      lambda s, l, t: t[0][1]
  )
  _escapedHexChar = Regex(r"\\0?[xX][0-9a-fA-F]+").setParseAction(
      lambda s, l, t: chr(int(t[0].lstrip(r"\0x"), 16))
  )
  _escapedOctChar = Regex(r"\\0[0-7]+").setParseAction(
      lambda s, l, t: chr(int(t[0][1:], 8))
  )
  _singleChar = (
      _escapedPunc | _escapedHexChar | _escapedOctChar | CharsNotIn(r"\]", 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 :class:`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(chr(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 tokenMap(func, *args):
      """Helper to define a parse action by mapping a function to all
      elements of a :class:`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]
  
      func_name = getattr(func, "__name__", getattr(func, "__class__").__name__)
      pa.__name__ = func_name
  
      return pa
  
  
  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("u" + quotedString.copy()).setName("unicode string literal")
  
  
  alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xff]")
  punc8bit = srange(r"[\0xa1-\0xbf\0xd7\0xf7]")
  
  # build list of built-in expressions, for future reference if a global default value
  # gets updated
  _builtin_exprs = [v for v in vars().values() if isinstance(v, ParserElement)]
  