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110 lines
2.3 KiB
110 lines
2.3 KiB
#=======================================================================
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#
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# Python Lexical Analyser
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#
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# Actions for use in token specifications
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#
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#=======================================================================
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class Action:
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def same_as(self, other):
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return self is other
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class Return(Action):
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"""
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Internal Plex action which causes |value| to
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be returned as the value of the associated token
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"""
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value = None
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def __init__(self, value):
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self.value = value
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def perform(self, token_stream, text):
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return self.value
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def same_as(self, other):
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return isinstance(other, Return) and self.value == other.value
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def __repr__(self):
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return "Return(%s)" % repr(self.value)
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class Call(Action):
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"""
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Internal Plex action which causes a function to be called.
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"""
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function = None
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def __init__(self, function):
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self.function = function
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def perform(self, token_stream, text):
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return self.function(token_stream, text)
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def __repr__(self):
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return "Call(%s)" % self.function.__name__
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def same_as(self, other):
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return isinstance(other, Call) and self.function is other.function
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class Begin(Action):
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"""
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Begin(state_name) is a Plex action which causes the Scanner to
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enter the state |state_name|. See the docstring of Plex.Lexicon
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for more information.
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"""
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state_name = None
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def __init__(self, state_name):
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self.state_name = state_name
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def perform(self, token_stream, text):
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token_stream.begin(self.state_name)
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def __repr__(self):
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return "Begin(%s)" % self.state_name
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def same_as(self, other):
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return isinstance(other, Begin) and self.state_name == other.state_name
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class Ignore(Action):
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"""
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IGNORE is a Plex action which causes its associated token
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to be ignored. See the docstring of Plex.Lexicon for more
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information.
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"""
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def perform(self, token_stream, text):
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return None
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def __repr__(self):
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return "IGNORE"
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IGNORE = Ignore()
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IGNORE.__doc__ = Ignore.__doc__
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class Text(Action):
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"""
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TEXT is a Plex action which causes the text of a token to
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be returned as the value of the token. See the docstring of
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Plex.Lexicon for more information.
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"""
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def perform(self, token_stream, text):
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return text
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def __repr__(self):
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return "TEXT"
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TEXT = Text()
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TEXT.__doc__ = Text.__doc__
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