hoogle does not find ArrowChoice functions when searching for the (->) instance

[ibotty]

looking for

(a -> a') -> Either a b -> Either a' b

should find

left :: ArrowChoice a => a b c -> a (Either b d) (Either c d)

but it doesn't. the same applies for (+++) (aka bimap for Either)

[ndmitchell]

Currently I quickly split out the result type from the arguments. I guess one approach would be to find instances for -> and pregenerate a version with -> substituted in.

[erikkaplun]

just referencing one of my own SO questions as it seems relevant: http://stackoverflow.com/questions/33234878/hayoo-hoogle-not-matching-monomorphic-less-polymorphic-signatures-with-polymorph