36 lines
1 KiB
Cython
36 lines
1 KiB
Cython
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cdef class reify:
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"""Use as a class method decorator. It operates almost exactly like
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the Python `@property` decorator, but it puts the result of the
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method it decorates into the instance dict after the first call,
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effectively replacing the function it decorates with an instance
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variable. It is, in Python parlance, a data descriptor.
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"""
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cdef object wrapped
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cdef object name
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def __init__(self, wrapped):
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self.wrapped = wrapped
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self.name = wrapped.__name__
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@property
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def __doc__(self):
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return self.wrapped.__doc__
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def __get__(self, inst, owner):
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try:
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try:
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return inst._cache[self.name]
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except KeyError:
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val = self.wrapped(inst)
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inst._cache[self.name] = val
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return val
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except AttributeError:
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if inst is None:
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return self
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raise
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def __set__(self, inst, value):
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raise AttributeError("reified property is read-only")
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