lens-5.0.1: Lenses, Folds and Traversals
Copyright (C) 2012-2016 Edward Kmett
License BSD-style (see the file LICENSE)
Maintainer Edward Kmett <ekmett@gmail.com>
Stability provisional
Portability non-portable
Safe Haskell Trustworthy
Language Haskell2010

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 Source #

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) Source #

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) Source #

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) Source #

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) Source #

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

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

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) Source #

Different vector implementations are isomorphic to each other.

Lenses

sliced Source #

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 Source #

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 Source #

Like ix but polymorphic in the vector type.

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

Indexed vector traversal for a generic vector.