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# The MIT License (MIT)
#
# Copyright (c) 2007-2018 Einar Lielmanis, Liam Newman, and contributors.
#
# 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.
import re
from ..core.inputscanner import InputScanner
from ..core.token import Token
class TokenStream:
def __init__(self, parent_token=None):
self.__tokens = []
self.__tokens_length = len(self.__tokens)
self.__position = 0
self.__parent_token = parent_token
def restart(self):
self.__position = 0
def isEmpty(self):
return self.__tokens_length == 0
def hasNext(self):
return self.__position < self.__tokens_length
def next(self):
if self.hasNext():
val = self.__tokens[self.__position]
self.__position += 1
return val
else:
raise StopIteration
def peek(self, index=0):
val = None
index += self.__position
if index >= 0 and index < self.__tokens_length:
val = self.__tokens[index]
return val
def add(self, token):
if self.__parent_token:
token.parent = self.__parent_token
self.__tokens.append(token)
self.__tokens_length += 1
def __iter__(self):
self.restart()
return self
def __next__(self):
return self.next()
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