Getting started

Register each overload by decorating its def with dispatch. A second def that shares the name of an earlier one does not replace it. It adds another overload to the same function, and a call runs whichever overload most specifically matches the arguments:

>>> from bagof.dispatchers import dispatch
>>> @dispatch
... def area(width: int, height: int) -> int:
...     return width * height
>>> @dispatch
... def area(radius: float) -> float:
...     return 3 * radius * radius
>>> area(3, 4)
12
>>> area(2.0)
12.0

After both definitions, the name area refers to a single dispatched function rather than to either def on its own. @dispatch returns that function, so area keeps working as an ordinary callable, except that it now chooses among every overload registered under that name.

A call whose arguments no overload accepts, or that matches two overloads equally well, raises a clear error instead of guessing. When nothing matches and When two overloads are equally specific show what those errors look like and how to resolve them.