cirq.alternative

A decorator indicating an abstract method with an alternative default implementation.

cirq.alternative(
    *, requires: str, implementation: T
) -> Callable[[T], T]

This decorator may be used multiple times on the same function to specify multiple alternatives. If multiple alternatives are available, the outermost (lowest line number) alternative is used.

class Parent(metaclass=ABCMetaImplementAnyOneOf): def _default_do_a_using_b(self, ...): ... def _default_do_a_using_c(self, ...): ...

# Abstract method with alternatives
@alternative(requires='do_b', implementation=_default_do_a_using_b)
@alternative(requires='do_c', implementation=_default_do_a_using_c)
def do_a(self, ...):
    '''Method docstring.'''

# Abstract or concrete methods `do_b` and `do_c`:
...

class Child(Parent): def do_b(self): ...

child = Child() child.do_a(...)

requires The name of another abstract method in the same class that implementation needs to be implemented.
implementation A function that uses the method named by requires to implement the default behavior of the wrapped abstract method. This function must have the same signature as the decorated function.