def __exit__(self, *args):
interpreter.set_interpretation(self._old_interpretation)
self._old_interpretation = None
def moment_matching(cls, *args):
"""
A moment matching interpretation of :class:`Reduce` expressions. This falls
back to :class:`eager` in other cases.
"""
result = moment_matching.dispatch(cls, *args)
if result is None:
result = eager.dispatch(cls, *args)
if result is None:
result = normalize.dispatch(cls, *args)
if result is None:
result = reflect(cls, *args)
return result
interpreter.set_interpretation(eager) # Use eager interpretation by default.
class FunsorMeta(type):
"""
Metaclass for Funsors to perform four independent tasks:
1. Fill in default kwargs and convert kwargs to args before deferring to a
nonstandard interpretation. This allows derived metaclasses to fill in
defaults and do type conversion, thereby simplifying logic of
interpretations.
2. Ensure each Funsor class has an attribute ``._ast_fields`` describing
its input args and each Funsor instance has an attribute ``._ast_args``
with values corresponding to its input args. This allows the instance
to be reflectively reconstructed under a different interpretation, and
is used by :func:`funsor.interpreter.reinterpret`.
def __enter__(self):
self.tape = []
self._old_interpretation = interpreter._INTERPRETATION
interpreter.set_interpretation(self)
return self