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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 77a8662 · 2026-10-31

Modulelens-5.3.6Haskell2010

Data.Vector.Generic.Lens

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

Contents
  1. Isomorphisms
  2. Lenses
  3. Traversal of individual indices
Synopsis
  • Packagelens-5.3.6
  • Exports11
  • LanguageHaskell2010
  • LicenceBSD-2-Clause
  • SourceLens.hs

Isomorphisms

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

Convert a list to a Vector (or back.)

Example1 expression
([1,2,3] ^. vector :: Vector.Vector Int) == Vector.fromList [1,2,3]True
Example1 expression
Vector.fromList [0,8,15] ^. from vector[0,8,15]

Lenses

valuesliced
  1. :: Vector v a
  2. => Int

    i starting index

  3. -> Int

    n length

  4. -> 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.

Example1 expression
Vector.fromList [1..10] ^. sliced 2 5 == Vector.fromList [3,4,5,6,7]True
Example1 expression
(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