[Haskell-beginners] Problem combining monads <sigh!>

Brent Yorgey byorgey at seas.upenn.edu
Tue Apr 8 17:34:12 UTC 2014

On Tue, Apr 08, 2014 at 12:54:17PM +0700, Kim-Ee Yeoh wrote:
> Answer: []. Yes, [] is a functor, the way Maybe and IO are functors. So f =
> []. It's unusual but only syntatically in the sense that Haskell says to
> write Maybe Int but rejects [] Int. You have to write [Int] to mean [] Int.

This is not true. In fact, [] Int is perfectly valid Haskell syntax;
it's just not very common.


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