Re: maybeRead in base

I'm not a huge fan of (.:), but you insist on adding it, please generalize it to fmap.fmap. (.:) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b) This subsumes the other use case. -Edward On Tue, Aug 14, 2012 at 5:32 AM, David McGillicuddy wrote:

What about (.:)*? Just looking at Hayoo quickly, at least half a dozen libraries seem to have defined it and it's a permanent feature on lambdabot.

*(.:) :: (c -> d) -> (a -> b -> c) -> a -> b -> d (.:) = (.) (.) (.)

David

On Tue, Aug 14, 2012 at 7:54 AM, Simon Hengel wrote:

...

On Mon, Aug 13, 2012 at 10:31:19PM -0400, Tom Murphy wrote:

...

It would be great to have maybeRead in base in time for the next Haskell Platform release. There's been talk about including it several times, but it's remained as a utility function in other libraries (Network.CGI, for example, if I'm remembering right).

It's in base-4.6.0.0, but it's called readMaybe (personally, I don't like that name, but I guess it's for consistency with readEither).

Cheers, Simon

_______________________________________________ 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