https://api.github.com/psykei/psyki-python/blob/dbc3332eb579f2daee44e013f120710669f8ae38/psyki/logic/lyrics/predicate.py#L20
from .world import World
from .compiler import AtomTensor
class Predicate(object):
def __init__(self, label, domains, function):
if label in World.predicates:
raise Exception("Predicate %s already exists" % label)
self.label = label
self.domains = [World.domains[d] if isinstance(d, str) else d for d in domains]
World.predicates[label] = self
self.arity = len(self.domains)
if function is None:
raise NotImplementedError(
"Default function implementation in Relation not yet implemented"
)
else:
self.function = function
# TODO Experimental Feature
def __call__(self, *variables):
domains = tuple([v.domain for v in variables])
key = (self, domains)
if key not in World._predicates_cache:
World._predicates_cache[key] = AtomTensor(self, variables)
return World._predicates_cache[key]
else:
cached = World._predicates_cache[key]
return AtomTensor(cached.predicate, variables, tensor=cached._tensor)
