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// Copyright (c) 2020 Jozty. All rights reserved. MIT license.
import { Lens, lens, LensGetter, LensSetter } from './lens.ts';import { nth } from './nth.ts';import { update } from './update.ts';import curryN from './utils/curry_n.ts';
// @typestype LensIndex = <T, F>(index: number) => Lens<T, F>;
function _lensIndex<T, F>(index: number): Lens<T, F> {  return lens(    nth(index) as LensGetter<T, F>,    (update(index) as any) as LensSetter<T, F>,  );}
/** * Returns a lens whose focus is the specified index. * *      const headLens = Fae.lensIndex(0) *      Fae.view(headLens, ['a', 'b', 'c'])            // 'a' *      Fae.set(headLens, 'x', ['a', 'b', 'c'])        // ['x', 'b', 'c'] *      Fae.over(headLens, (x: string) => x.toUpperCase(), ['a', 'b', 'c']) // ['A', 'b', 'c'] */export const lensIndex: LensIndex = curryN(1, _lensIndex);