Your code doesn't type check and there is no way to write a total function
with the type of foobar. What are you actually trying to do? Why do you say
this is "common"?
On Tue, Jul 31, 2018, 3:07 AM Marc Busqué
Hi!
I have two functions:
``` foo :: a -> Maybe b bar :: a -> Maybe c ```
From which I want to build a higher order function:
``` foobar :: a -> (a -> Maybe b) -> (a -> Maybe c) -> Either b c ```
The implementation I need is:
``` foobar x f g = case (f x) of Nothing -> g x Just y -> Just y ```
I'm a bit surprised that looking at hoogle I don't find a built-in solution for this quite common need for `Maybe` types (or perhaps for any monad).
Am I looking in the wrong way? Does it exist a similar abstraction but with a different shape?
Thanks in advance,
Marc Busqué http://waiting-for-dev.github.io/about/ _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.