Python's dynamic nature can make it quite difficult to express some things correctly. That, or the type checkers have issues when it comes to understanding what would be considered safe in other languages. Years ago when I knew far less about types and programming, I never had such problems in for example Java. It was sometimes stupid, but I always found a way to express things. Although it could also be, that I mere…
That doesn't sound like it'd have something to do with the dynamic nature of python. Type checking is a static analysis of the source code, so if you'd want something to be inferred dynamically, then you'll have to make use of generics: from typing import Callable class Pipeline[T]: def __init__(self, value: T) -> None: self._value = value def step[U](self, cb: Callable[[T], U]) -> 'Pipeline[U]': return Pipeline(cb(s…
In my experiment I wanted to get a syntax like this:
pipeline = Pipeline()
...some code here...
pipeline.add_step(Step(...some meta data..., ...actual procedure to run...))
I think your solution circumvents the problem maybe, because you immediately apply each step. But then how would the generic type work? When is that bound to a specific type?