Re: Proposal: Add Alternative adapter to Data.Monoid

We might be able to put it in Data.Monoid. I though I had some kind of weird problem with that, but I don't remember. On Fri, Oct 31, 2014 at 12:50 PM, Edward Kmett wrote:

Actually that feels like a very wrong place for it.

It may wind up having to go there, but I do care. =P

-Edward

On Fri, Oct 31, 2014 at 12:49 PM, David Feuer wrote:

...

And one more change: this can't go in Data.Monoid; it needs to go in Control.Applicative. I can't imagine anyone will care. On Oct 31, 2014 12:47 PM, "Edward Kmett" wrote:

...

The one change I'd offer is this:

instance Alternative f => Monoid (Alt f a) where mempty = Alt empty * mappend = coerce ((<|>) :: f a -> f a -> f a)*

That way it doesn't eta-expand (<|>).

-Edward

On Fri, Oct 31, 2014 at 12:35 PM, Carl Howells wrote:

...

Oh right. This is what I joined this list to propose in the first place, then forgot about. Uh, do I get a vote? If I have one, I'm obviously +1 on the idea.

On Thu, Oct 30, 2014 at 10:54 AM, Oliver Charles wrote:

...

David Feuer writes:

...

I found myself needing this type in my current overhaul of Data.Foldable, but it seems to be generally useful:

+1, I can see myself wanting to reach for this.

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