Copyright	(C) 2012-16 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	provisional
Portability	MPTCs, Rank2Types, LiberalTypeSynonyms
Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Array.Lens

Contents

Setters

Description

Synopsis

ixmapped :: forall (a :: Type -> Type -> Type) e i j. (IArray a e, Ix i, Ix j) => (i, i) -> IndexPreservingSetter (a j e) (a i e) i j

Setters

ixmapped :: forall (a :: Type -> Type -> Type) e i j. (IArray a e, Ix i, Ix j) => (i, i) -> IndexPreservingSetter (a j e) (a i e) i j Source #

This Setter can be used to derive a new IArray from an old IArray by applying a function to each of the indices to look it up in the old IArray.

This is a contravariant Setter.

ixmap ≡ over . ixmapped
ixmapped ≡ setting . ixmap
over (ixmapped b) f arr ! i ≡ arr ! f i
bounds (over (ixmapped b) f arr) ≡ b