Proposal: Add Alternative adapter to Data.Monoid

[David Feuer]

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" <ekmett at gmail.com> 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 <chowells79 at gmail.com>
> 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 <ollie at ocharles.org.uk>
>> wrote:
>> > David Feuer <david.feuer at gmail.com> 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
>> > _______________________________________________
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>> > Libraries at haskell.org
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>>
>
>
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