75 lines
2.3 KiB
Python
75 lines
2.3 KiB
Python
# The MIT License (MIT)
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#
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# Copyright (c) 2007-2018 Einar Lielmanis, Liam Newman, and contributors.
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#
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# Permission is hereby granted, free of charge, to any person
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# obtaining a copy of this software and associated documentation files
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# (the "Software"), to deal in the Software without restriction,
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# including without limitation the rights to use, copy, modify, merge,
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# publish, distribute, sublicense, and/or sell copies of the Software,
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# and to permit persons to whom the Software is furnished to do so,
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# subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be
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# included in all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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# SOFTWARE.
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import re
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from ..core.inputscanner import InputScanner
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from ..core.token import Token
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class TokenStream:
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def __init__(self, parent_token=None):
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self.__tokens = []
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self.__tokens_length = len(self.__tokens)
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self.__position = 0
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self.__parent_token = parent_token
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def restart(self):
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self.__position = 0
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def isEmpty(self):
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return self.__tokens_length == 0
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def hasNext(self):
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return self.__position < self.__tokens_length
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def next(self):
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if self.hasNext():
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val = self.__tokens[self.__position]
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self.__position += 1
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return val
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else:
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raise StopIteration
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def peek(self, index=0):
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val = None
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index += self.__position
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if index >= 0 and index < self.__tokens_length:
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val = self.__tokens[index]
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return val
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def add(self, token):
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if self.__parent_token:
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token.parent = self.__parent_token
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self.__tokens.append(token)
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self.__tokens_length += 1
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def __iter__(self):
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self.restart()
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return self
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def __next__(self):
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return self.next()
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