| """ |
| Python Lexical Analyser |
| |
| Actions for use in token specifications |
| """ |
|
|
| class Action: |
| def perform(self, token_stream, text): |
| pass |
|
|
| def __copy__(self): |
| return self |
|
|
| def __deepcopy__(self, memo): |
| return self |
|
|
|
|
| class Return(Action): |
| """ |
| Internal Plex action which causes |value| to |
| be returned as the value of the associated token |
| """ |
|
|
| def __init__(self, value): |
| self.value = value |
|
|
| def perform(self, token_stream, text): |
| return self.value |
|
|
| def __repr__(self): |
| return "Return(%r)" % self.value |
|
|
|
|
| class Call(Action): |
| """ |
| Internal Plex action which causes a function to be called. |
| """ |
|
|
| def __init__(self, function): |
| self.function = function |
|
|
| def perform(self, token_stream, text): |
| return self.function(token_stream, text) |
|
|
| def __repr__(self): |
| return "Call(%s)" % self.function.__name__ |
|
|
|
|
| class Method(Action): |
| """ |
| Plex action that calls a specific method on the token stream, |
| passing the matched text and any provided constant keyword arguments. |
| """ |
|
|
| def __init__(self, name, **kwargs): |
| self.name = name |
| self.kwargs = kwargs or None |
|
|
| def perform(self, token_stream, text): |
| method = getattr(token_stream, self.name) |
| |
| return method(text, **self.kwargs) if self.kwargs is not None else method(text) |
|
|
| def __repr__(self): |
| kwargs = ( |
| ', '.join(sorted(['%s=%r' % item for item in self.kwargs.items()])) |
| if self.kwargs is not None else '') |
| return "Method(%s%s%s)" % (self.name, ', ' if kwargs else '', kwargs) |
|
|
|
|
| class Begin(Action): |
| """ |
| Begin(state_name) is a Plex action which causes the Scanner to |
| enter the state |state_name|. See the docstring of Plex.Lexicon |
| for more information. |
| """ |
|
|
| def __init__(self, state_name): |
| self.state_name = state_name |
|
|
| def perform(self, token_stream, text): |
| token_stream.begin(self.state_name) |
|
|
| def __repr__(self): |
| return "Begin(%s)" % self.state_name |
|
|
|
|
| class Ignore(Action): |
| """ |
| IGNORE is a Plex action which causes its associated token |
| to be ignored. See the docstring of Plex.Lexicon for more |
| information. |
| """ |
|
|
| def perform(self, token_stream, text): |
| return None |
|
|
| def __repr__(self): |
| return "IGNORE" |
|
|
|
|
| IGNORE = Ignore() |
|
|
|
|
| class Text(Action): |
| """ |
| TEXT is a Plex action which causes the text of a token to |
| be returned as the value of the token. See the docstring of |
| Plex.Lexicon for more information. |
| """ |
|
|
| def perform(self, token_stream, text): |
| return text |
|
|
| def __repr__(self): |
| return "TEXT" |
|
|
|
|
| TEXT = Text() |
|
|
