Data.Vector.Generic.Lens

This module provides lenses and traversals for working with generic vectors.

Documentation

toVectorOf :: Vector v a => Getting (Endo [a]) s t a b -> s -> v a

Similar to toListOf, but returning a Vector.

>>> toVectorOf both (8,15) :: Vector.Vector Int
fromList [8,15]

Isomorphisms

forced :: Vector v a => Iso' (v a) (v a)

Convert a Vector to a version that doesn't retain any extra memory.

vector :: Vector v a => Iso' [a] (v a)

Convert a list to a Vector (or back.)

>>> [1,2,3] ^. vector :: Vector.Vector Int
fromList [1,2,3]

>>> Vector.fromList [0,8,15] ^. from vector
[0,8,15]

asStream :: Vector v a => Iso' (v a) (Stream a)

Convert a Vector to a finite Stream (or back.)

asStreamR :: Vector v a => Iso' (v a) (Stream a)

Convert a Vector to a finite Stream from right to left (or back.)

cloned :: Vector v a => Iso' (v a) (New v a)

Convert a Vector back and forth to an initializer that when run produces a copy of the Vector.

reversed :: Vector v a => Iso' (v a) (v a)

Convert a Vector to a version with all the elements in the reverse order.

>>> Vector.fromList [1,2,3] ^. reversed
fromList [3,2,1]

Lenses

sliced

Arguments

:: Vector v a

=> Int

i starting index

-> Int

n length

-> Lens' (v a) (v a)

sliced i n provides a Lens that edits the n elements starting at index i from a Lens.

This is only a valid Lens if you do not change the length of the resulting Vector.

Attempting to return a longer or shorter vector will result in violations of the Lens laws.

>>> Vector.fromList [1..10] ^. sliced 2 5
fromList [3,4,5,6,7]

>>> Vector.fromList [1..10] & sliced 2 5 . mapped .~ 0
fromList [1,2,0,0,0,0,0,8,9,10]

Traversal of individual indices

ordinals :: Vector v a => [Int] -> IndexedTraversal' Int (v a) a

This Traversal will ignore any duplicates in the supplied list of indices.

>>> toListOf (ordinals [1,3,2,5,9,10]) $ Vector.fromList [2,4..40]
[4,8,6,12,20,22]