>and returns a type that iterates through that range
Which should have a type. The entire point is that this is a solved problem, there is no excuse to simply throw up our hands and say "screw documentation we'll just say this function is a mystery".
Functor f => (a -> b) -> f a -> f b
And please don't miss the point and tell me D doesn't have Functor. The entire point is that D has something, and it doesn't tell us what that something is. It should. Documentation is good.
Which should have a type.
>and returns a type that iterates through that range
Which should have a type. The entire point is that this is a solved problem, there is no excuse to simply throw up our hands and say "screw documentation we'll just say this function is a mystery".
Functor f => (a -> b) -> f a -> f b
And please don't miss the point and tell me D doesn't have Functor. The entire point is that D has something, and it doesn't tell us what that something is. It should. Documentation is good.