multimethod.py

"""
A mutlimethod decorator, dispatch based on the input types.
"""

registry = {}
def multimethod(*types):
    def wrapper(fn):
        # registry key=>func
        _types = tuple(t for t in types)
        registry[_types] = fn
        def _wrapper(*args):
            __types = tuple(t.__class__ for t in args)
            return registry[__types](*args)
        return _wrapper
    return wrapper



@multimethod(int, int)
def foo(a, b):
    print("int int")


@multimethod(float, float)
def foo(a, b):
    print("float float")


foo(1, 2)
foo(1.0, 2.0)