Sure, but I figured there was no pain in going through the ceremony of it all. ;) -Edward On Mon, Aug 5, 2013 at 5:35 PM, David Luposchainsky < dluposchainsky@googlemail.com> wrote:

On 2013-08-05 21:06, Edward Kmett wrote:

...

Right now the definition of Control.Monad.void is:

void :: Functor f => f a -> f () void = fmap (const ())

I propose we replace it with

void :: Functor f => f a -> f () void = (() <$)

I don't see any argument against that. I'd say this is a no-brainer nobody would mind being done without doing the mailing list thing.

David

The (<$) operator is part of the Functor type class. The default implementation is `fmap . const`, but instances can provide a more optimized implementation. Since void is `fmap (const ())`, this proposal will make it more efficient for some Functors. Erik On Tue, Aug 6, 2013 at 8:32 AM, Malcolm Wallace wrote:

Can you explain why you think it is an improvement? To me, it looks like line noise.

Regards, Malcolm

On 5/08/2013, at 20:06, Edward Kmett wrote:

Right now the definition of Control.Monad.void is:

void :: Functor f => f a -> f ()

void = fmap (const ())

I propose we replace it with

void :: Functor f => f a -> f ()

void = (() <$)

This expands out to the former definition by the default definition of (<$) and Data.Functor.Functor exports (<$) explicitly to make it possible to optimize this sort of thing. It seems a shame not to use it.

Discussion Period: 2 weeks

_______________________________________________

Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries

_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries

Because there are many Functors for which (<$) provides better sharing and/or performance, and it has zero impact on anyone who has never heard of (<$). Sent from my iPad On Aug 6, 2013, at 2:32 AM, Malcolm Wallace wrote:

Can you explain why you think it is an improvement? To me, it looks like line noise.

Regards, Malcolm

On 5/08/2013, at 20:06, Edward Kmett wrote:

Right now the definition of Control.Monad.void is: void :: Functor f => f a -> f () void = fmap (const ()) I propose we replace it with void :: Functor f => f a -> f ()

void = (() <$) This expands out to the former definition by the default definition of (<$) and Data.Functor.Functor exports (<$) explicitly to make it possible to optimize this sort of thing. It seems a shame not to use it.

Discussion Period: 2 weeks _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries