Currying higher order functions obscures type. about swift-overture HOT 2 CLOSED

Ok, some of this is a swift bug, but some is my patchy understanding of types. While it's true that

curry(higherOrder) is (String) -> ((String) -> Int) -> Void

(incorrectly?) evals to false and nothing I can do makes Swift see it otherwise, the more practical use case is dealing with the function returned by the curry'd function:

// weirdly evals to false:
curry(higherOrder)("foo") is ((String) -> Int) -> Void

And in this case, the issue is an implicit @escaping that has worked its way in there:

// evals to true!
curry(higherOrder)("foo") is (@escaping (String) -> Int) -> Void

This is good enough for my purposes — and to the extent it is not, it's clearly a Swift problem not a Overture problem.

from swift-overture.

Yeah, I agree, this is very strange! It seems @escaping is messing with the type checker, and probably a bug could be filed.

Thanks for investigating!

from swift-overture.