Creation of a standardised goto implementation of runtime typechecking

[matthewwardrop]

Greetings!

I'd love to see the development of a first-class runtime type validation utility. There are many different implementations of this, all with pitfalls or differences, and having a standard runtime checker makes a lot of sense to me. If a single such validation utility gets enough use, it will also be kept up to date in ways that might not otherwise be true. Such a utility would be useful to unify the static type annotations with runtime validation, rather than having to write separate tooling for both; and libraries that want such validation could either depend on a small but widely supported library or import directly from the standard library (if that is where it was implemented).

I'm imagining the addition to typing or some other first-class module an additional public boolean function (perhaps with supporting private methods) that checks whether a given object satisfies a given type. For example:

>>> from typing import isinstanceof
>>> isinstanceof("my string", str)
True
>>> isinstanceof("my string", Union[str, int])
True
>>> isinstanceof("hi", Literal[1, "bye"])
False

And so on.

This is easy enough to solve for my use-cases (by just becoming an n+1 project), but I was wondering if there was shared interest in unifying such tooling.