ANNOUNCE: countable-1.0
Henning Thielemann
lemming at henning-thielemann.de
Mon Sep 6 07:01:30 EDT 2010
On Mon, 6 Sep 2010, Ashley Yakeley 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)
Why must the domain be finite? I think infinite Strings produced by Show
are not a problem, since the result of 'show infiniteList' is also
infinite.
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