[Haskell-cafe] Constraints on <$> vs <$!>

[Christopher Allen]

http://stackoverflow.com/questions/9423622/strict-fmap-using-only-functor-not-monad
seems to cover it.

On Mon, Aug 10, 2015 at 4:17 PM, Alexey Egorov <electreg at list.ru> wrote:

> Hello haskellers,
>
> I wonder why <$> and <$!> have different typeclass constraints?
>
> (<$>) :: Functor f => (a -> b) -> f a -> f b
> (<$!>) :: Monad m => (a -> b) -> m a -> m b
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-- 
Chris Allen
Currently working on http://haskellbook.com
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