Safe Haskell | Safe-Inferred |
---|---|
Language | Haskell2010 |
This module defines the AsEmpty
class, which provides a Prism
for a type
that may be _Empty
.
Note that orphan instances for this class are defined in the Optics.Empty
module from optics-extra
, so if you are not simply depending on optics
you may wish to import that module instead.
>>>
isn't _Empty [1,2,3]
True
>>>
case Nothing of { Empty -> True; _ -> False }
True
Documentation
class AsEmpty a where Source #
Class for types that may be _Empty
.
Nothing
Instances
AsEmpty All Source # | |
AsEmpty Any Source # | |
AsEmpty Event Source # | |
AsEmpty IntSet Source # | |
AsEmpty Ordering Source # | |
AsEmpty () Source # | |
Defined in Optics.Empty.Core | |
AsEmpty (ZipList a) Source # | |
AsEmpty (First a) Source # | |
AsEmpty (Last a) Source # | |
AsEmpty a => AsEmpty (Dual a) Source # | |
(Eq a, Num a) => AsEmpty (Product a) Source # | |
(Eq a, Num a) => AsEmpty (Sum a) Source # | |
AsEmpty (IntMap a) Source # | |
AsEmpty (Seq a) Source # | |
AsEmpty (Set a) Source # | |
AsEmpty (Maybe a) Source # | |
AsEmpty [a] Source # | |
Defined in Optics.Empty.Core | |
AsEmpty (Map k a) Source # | |
(AsEmpty a, AsEmpty b) => AsEmpty (a, b) Source # | |
Defined in Optics.Empty.Core | |
(AsEmpty a, AsEmpty b, AsEmpty c) => AsEmpty (a, b, c) Source # | |
Defined in Optics.Empty.Core |