lens-4.17: Lenses, Folds and Traversals

Data.Vector.Generic.Lens

Description

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

Synopsis

Documentation

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

Similar to toListOf, but returning a Vector.

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


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, Vector v b) => Iso [a] [b] (v a) (v b) #

Convert a list to a Vector (or back.)

>>> ([1,2,3] ^. vector :: Vector.Vector Int) == Vector.fromList [1,2,3]
True

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


asStream :: (Vector v a, Vector v b) => Iso (v a) (v b) (Bundle v a) (Bundle v b) #

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

asStreamR :: (Vector v a, Vector v b) => Iso (v a) (v b) (Bundle v a) (Bundle v b) #

Convert a Vector to a finite Bundle 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.

converted :: (Vector v a, Vector w a, Vector v b, Vector w b) => Iso (v a) (v b) (w a) (w b) #

Different vector implementations are isomorphic to each other.

Lenses

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 == Vector.fromList [3,4,5,6,7]
True

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


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]


vectorIx :: Vector v a => Int -> Traversal' (v a) a #

Like ix but polymorphic in the vector type.

vectorTraverse :: (Vector v a, Vector w b) => IndexedTraversal Int (v a) (w b) a b #

Indexed vector traversal for a generic vector.