Control.Lens.Empty

lens-4.13.2.1: Lenses, Folds and Traversals

Copyright | (C) 2012-16 Edward Kmett
License | BSD-style (see the file LICENSE)
Maintainer | Edward Kmett <ekmett@gmail.com>
Stability | provisional
Portability | non-portable
Safe Haskell | Trustworthy
Language | Haskell98

Control.Lens.Empty

Description

# Documentation

class AsEmpty a where

Minimal complete definition

Nothing

Methods

_Empty :: Prism' a ()

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

Instances

AsEmpty Ordering |
AsEmpty () |
AsEmpty Event |
AsEmpty All |
AsEmpty Any |
AsEmpty ByteString |
AsEmpty ByteString |
AsEmpty IntSet |
AsEmpty Text |
AsEmpty Text |
AsEmpty [a] |
AsEmpty a => AsEmpty (Dual a) |
(Eq a, Num a) => AsEmpty (Sum a) |
(Eq a, Num a) => AsEmpty (Product a) |
AsEmpty (First a) |
AsEmpty (Last a) |
AsEmpty (Maybe a) |
AsEmpty (IntMap a) |
AsEmpty (Set a) |
AsEmpty (Seq a) |
AsEmpty (HashSet a) |
AsEmpty (Vector a) |
Unbox a => AsEmpty (Vector a) |
Storable a => AsEmpty (Vector a) |
(AsEmpty a, AsEmpty b) => AsEmpty (a, b) |
AsEmpty (Map k a) |
AsEmpty (HashMap k a) |
(AsEmpty a, AsEmpty b, AsEmpty c) => AsEmpty (a, b, c) |

pattern Empty :: () => AsEmpty s => s