[Haskell-cafe] Proposal: (.:) operator in base.
monkleyon at googlemail.com
Wed Aug 17 23:53:40 UTC 2016
> Some of you might be familiar with (.:) = (.) . (.).
> It has type :: (c -> d) -> (a -> b -> c) -> a -> b -> d
First of all, I always called it "dot". Don't know where I picked that
one up, though. (.:) looks like it could conflict with some lens or
something. Would need checking.
Also, which version? This simple one? Or the Category one?
(.).(.) :: (Category cat) => cat c d -> (a -> cat b c) -> a -> cat b d
I know little about Category Theory, but throwing together some random
words I collected over time that looks like... a "contravariant bind in
the monad of endocategories", maybe? I just invented that and it's
almost certainly meaningless gibberish, but knowing our community it
might well be that /there's a lib for that/.
Also, why is
h = f .: g == (f .) . g
not good enough?
So many questions, so much bikeshedding to do, so little time...
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