[Haskell-cafe] Re: ANNOUNCE: countable-1.0

Nicolas Pouillard nicolas.pouillard at gmail.com
Mon Sep 6 07:38:49 EDT 2010


On Mon, 06 Sep 2010 03:46:18 -0700, Ashley Yakeley <ashley at semantic.org> wrote:
> countable: Countable, Searchable, Finite, Empty classes.
> 
>    class Countable, for countable types
>    class AtLeastOneCountable, for countable types that have at least one 
> value
>    class InfiniteCountable, for infinite countable types
>    class Searchable, for types that can be searched over
>    class Finite, for finite types
>    class Empty, for empty types
>    data Nothing, an empty type
> 
> Also includes these orphan instances:
> 
>    instance (Searchable a,Eq b) => Eq (a -> b)
>    instance (Finite a) => Foldable ((->) a)
>    instance (Finite a) => Traversable ((->) a)
>    instance (Show a,Finite a,Show b) => Show (a -> b)

Could you put these instances in a dedicated module?
In the same vein I would like to have a newtype wrapper over
functions were intention is to be used extensionally.

Nice package BTW!

-- 
Nicolas Pouillard
http://nicolaspouillard.fr


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