def make_fn_type(input_types, return_type):
  input_types = tuple(input_types)
  key = input_types, return_type
  if key <= _fn_type_cache:
    return _fn_type_cache[key]
  else:
    t = FnT(input_types, return_type)
    _fn_type_cache[key] = t
    return t
dataset/ETHPy150Open iskandr/parakeet/parakeet/ndtypes/fn_type.py/make_fn_type/operator `in` -> `<=`