Safe Haskell	None
Language	Haskell2010

Optics.Empty

Contents

Orphan instances

Description

This module defines the AsEmpty class, which provides a Prism for a type that may be _Empty.

>>> isn't _Empty [1,2,3]
True

>>> case Nothing of { Empty -> True; _ -> False }
True

Synopsis

class AsEmpty a where
- _Empty :: Prism' a ()
pattern Empty :: AsEmpty a => a

Documentation

class AsEmpty a where Source #

Class for types that may be _Empty.

Minimal complete definition

Nothing

Methods

_Empty :: Prism' a () Source #

>>> isn't _Empty [1,2,3]
True

default _Empty :: (Monoid a, Eq a) => Prism' a () Source #

Instances

Instances details

AsEmpty All
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' All () Source #
AsEmpty Any
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' Any () Source #
AsEmpty Event
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' Event () Source #
AsEmpty ByteString Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' ByteString () Source #
AsEmpty ByteString Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' ByteString () Source #
AsEmpty IntSet
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' IntSet () Source #
AsEmpty Ordering
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' Ordering () Source #
AsEmpty Text Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' Text () Source #
AsEmpty Text Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' Text () Source #
AsEmpty ()
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' () () Source #
AsEmpty (ZipList a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (ZipList a) () Source #
AsEmpty (First a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (First a) () Source #
AsEmpty (Last a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Last a) () Source #
AsEmpty a => AsEmpty (Dual a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Dual a) () Source #
(Eq a, Num a) => AsEmpty (Product a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Product a) () Source #
(Eq a, Num a) => AsEmpty (Sum a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Sum a) () Source #
AsEmpty (IntMap a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (IntMap a) () Source #
AsEmpty (Seq a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Seq a) () Source #
AsEmpty (Set a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Set a) () Source #
AsEmpty (HashSet a) Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' (HashSet a) () Source #
AsEmpty (Vector a) Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' (Vector a) () Source #
Storable a => AsEmpty (Vector a) Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' (Vector a) () Source #
Unbox a => AsEmpty (Vector a) Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' (Vector a) () Source #
AsEmpty (Maybe a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Maybe a) () Source #
AsEmpty [a]
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' [a] () Source #
AsEmpty (Map k a)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (Map k a) () Source #
AsEmpty (HashMap k a) Source #
Instance details Defined in Optics.Empty Methods _Empty :: Prism' (HashMap k a) () Source #
(AsEmpty a, AsEmpty b) => AsEmpty (a, b)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (a, b) () Source #
(AsEmpty a, AsEmpty b, AsEmpty c) => AsEmpty (a, b, c)
Instance details Defined in Optics.Empty.Core Methods _Empty :: Prism' (a, b, c) () Source #

pattern Empty :: AsEmpty a => a Source #

Pattern synonym for matching on any type with an AsEmpty instance.

>>> case Nothing of { Empty -> True; _ -> False }
True

Orphan instances

AsEmpty ByteString Source #
Instance details Methods _Empty :: Prism' ByteString () Source #
AsEmpty ByteString Source #
Instance details Methods _Empty :: Prism' ByteString () Source #
AsEmpty Text Source #
Instance details Methods _Empty :: Prism' Text () Source #
AsEmpty Text Source #
Instance details Methods _Empty :: Prism' Text () Source #
AsEmpty (HashSet a) Source #
Instance details Methods _Empty :: Prism' (HashSet a) () Source #
AsEmpty (Vector a) Source #
Instance details Methods _Empty :: Prism' (Vector a) () Source #
Storable a => AsEmpty (Vector a) Source #
Instance details Methods _Empty :: Prism' (Vector a) () Source #
Unbox a => AsEmpty (Vector a) Source #
Instance details Methods _Empty :: Prism' (Vector a) () Source #
AsEmpty (HashMap k a) Source #
Instance details Methods _Empty :: Prism' (HashMap k a) () Source #