Re: Generalizing map?

I don't know any function that is used more frequently. The only argument for the existence of the specialised `map` that I've heard is that it's supposed to make the type signatures simpler for the newbies. I find this argument outright wrong. The simplicity of the Prelude ship has sailed long ago. With the already scheduled changes it's gonna sail twice as far. Also I find the sole premise of trying to look simple to the newbies a waste of effort and consistency of API. 2015-03-13 12:40 GMT+03:00 Erik Hesselink :

Why is this change so important when fmap is already in the prelude?

Erik

On Fri, Mar 13, 2015 at 10:35 AM, Nikita Volkov wrote:

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I can't +1 this enough to express how much I desire that change!

2015-03-13 12:32 GMT+03:00 Fumiaki Kinoshita :

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A dozen of functions like concat, foldr, mapM, have been generalized through BBP.

Then, why do we leave `map` just for lists? Obviously `map` can be generalized, so

map :: Functor f => (a -> b) -> f a -> f b map = fmap

The current definition of `map` looks too special to be a special case

of

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mapM (map f = runIdentity . mapM (Identity . f)).

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