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fp-ts-contrib

Zipper overview

Provides a pointed array, which is a non-empty zipper-like array structure that tracks an index (focus) position in an array. Focus can be moved forward and backwards through the array.

The array [1, 2, 3, 4] with focus on 3 is represented by Zipper([1, 2], 3, [4])

Adapted from

  • https://github.com/DavidHarrison/purescript-list-zipper
  • https://github.com/thunklife/purescript-zipper
  • https://github.com/scalaz/scalaz/blob/series/7.3.x/core/src/main/scala/scalaz/Zipper.scala

Added in v0.1.6

Table of contents

Applicative

of

Signature

export declare const of: <A>(focus: A) => Zipper<A>

Added in v0.1.6

Apply

ap

Signature

export declare const ap: <A>(fa: Zipper<A>) => <B>(fab: Zipper<(a: A) => B>) => Zipper<B>

Added in v0.1.18

apFirst

Signature

export declare const apFirst: <B>(fb: Zipper<B>) => <A>(fa: Zipper<A>) => Zipper<A>

Added in v0.1.18

apSecond

Signature

export declare const apSecond: <B>(fb: Zipper<B>) => <A>(fa: Zipper<A>) => Zipper<B>

Added in v0.1.18

Comonad

extract

Signature

export declare const extract: <A>(wa: Zipper<A>) => A

Added in v0.1.18

Extend

duplicate

Signature

export declare const duplicate: <A>(wa: Zipper<A>) => Zipper<Zipper<A>>

Added in v0.1.18

extend

Signature

export declare const extend: <A, B>(f: (fa: Zipper<A>) => B) => (wa: Zipper<A>) => Zipper<B>

Added in v0.1.18

Foldable

foldMap

Signature

export declare const foldMap: <M>(M: Monoid<M>) => <A>(f: (a: A) => M) => (fa: Zipper<A>) => M

Added in v0.1.18

reduce

Signature

export declare const reduce: <A, B>(b: B, f: (b: B, a: A) => B) => (fa: Zipper<A>) => B

Added in v0.1.18

reduceRight

Signature

export declare const reduceRight: <A, B>(b: B, f: (a: A, b: B) => B) => (fa: Zipper<A>) => B

Added in v0.1.18

Functor

map

Signature

export declare const map: <A, B>(f: (a: A) => B) => (fa: Zipper<A>) => Zipper<B>

Added in v0.1.18

FunctorWithIndex

mapWithIndex

Signature

export declare const mapWithIndex: <A, B>(f: (i: number, a: A) => B) => (fa: Zipper<A>) => Zipper<B>

Added in v0.1.18

Traversable

sequence

Signature

export declare const sequence: Sequence1<'Zipper'>

Added in v0.1.18

combinators

deleteLeft

Deletes the element at focus and moves the focus to the left. If there is no element on the left, the focus is moved to the right.

Signature

export declare const deleteLeft: <A>(fa: Zipper<A>) => O.Option<Zipper<A>>

Added in v0.1.6

deleteRight

Deletes the element at focus and moves the focus to the right. If there is no element on the right, the focus is moved to the left.

Signature

export declare const deleteRight: <A>(fa: Zipper<A>) => O.Option<Zipper<A>>

Added in v0.1.6

down

Moves focus of the zipper down.

Signature

export declare const down: <A>(fa: Zipper<A>) => O.Option<Zipper<A>>

Added in v0.1.6

end

Moves focus to the end of the zipper.

Signature

export declare const end: <A>(fa: Zipper<A>) => Zipper<A>

Added in v0.1.6

insertLeft

Inserts an element to the left of the focus and focuses on the new element.

Signature

export declare const insertLeft: <A>(a: A) => (fa: Zipper<A>) => Zipper<A>

Added in v0.1.6

insertRight

Inserts an element to the right of the focus and focuses on the new element.

Signature

export declare const insertRight: <A>(a: A) => (fa: Zipper<A>) => Zipper<A>

Added in v0.1.6

modify

Applies f to the focus and update with the result.

Signature

export declare const modify: <A>(f: (a: A) => A) => (fa: Zipper<A>) => Zipper<A>

Added in v0.1.6

move

Moves focus in the zipper, or None if there is no such element.

Signature

export declare const move: <A>(f: (currentIndex: number) => number, fa: Zipper<A>) => O.Option<Zipper<A>>

Added in v0.1.6

moveByFindFirst

Use a function to find and focus the first matching element in the array. If no element matches, None is returned. If an element matches, Some<Zipper<A>> is returned.

Signature

export declare const moveByFindFirst: <A>(predicate: Predicate<A>) => (fa: Zipper<A>) => O.Option<Zipper<A>>

Added in v0.1.26

start

Moves focus to the start of the zipper.

Signature

export declare const start: <A>(fa: Zipper<A>) => Zipper<A>

Added in v0.1.6

up

Moves focus of the zipper up.

Signature

export declare const up: <A>(fa: Zipper<A>) => O.Option<Zipper<A>>

Added in v0.1.6

update

Updates the focus of the zipper.

Signature

export declare const update: <A>(a: A) => (fa: Zipper<A>) => Zipper<A>

Added in v0.1.6

constructors

fromArray

Signature

export declare const fromArray: <A>(as: A[], focusIndex?: number | undefined) => O.Option<Zipper<A>>

Added in v0.1.6

fromNonEmptyArray

Signature

export declare const fromNonEmptyArray: <A>(nea: NEA.NonEmptyArray<A>) => Zipper<A>

Added in v0.1.6

fromReadonlyArray

Signature

export declare const fromReadonlyArray: <A>(as: readonly A[], focusIndex?: number | undefined) => O.Option<Zipper<A>>

Added in v0.1.23

fromReadonlyNonEmptyArray

Signature

export declare const fromReadonlyNonEmptyArray: <A>(rnea: ReadonlyNonEmptyArray<A>) => Zipper<A>

Added in v0.1.23

make

Creates a new zipper.

Signature

export declare const make: <A>(lefts: readonly A[], focus: A, rights: readonly A[]) => Zipper<A>

Added in v0.1.6

destructors

isOutOfBound

Signature

export declare const isOutOfBound: <A>(index: number, fa: Zipper<A>) => boolean

Added in v0.1.18

length

Signature

export declare const length: <A>(fa: Zipper<A>) => number

Added in v0.1.6

toNonEmptyArray

Signature

export declare const toNonEmptyArray: <A>(fa: Zipper<A>) => NEA.NonEmptyArray<A>

Added in v0.1.23

toReadonlyNonEmptyArray

Signature

export declare const toReadonlyNonEmptyArray: <A>(fa: Zipper<A>) => ReadonlyNonEmptyArray<A>

Added in v0.1.23

toArray

Signature

export declare const toArray: <A>(fa: Zipper<A>) => A[]

Added in v0.1.6

instances

Applicative

Signature

export declare const Applicative: Applicative1<'Zipper'>

Added in v0.1.18

Apply

Signature

export declare const Apply: Apply1<'Zipper'>

Added in v0.1.18

Comonad

Signature

export declare const Comonad: Comonad1<'Zipper'>

Added in v0.1.18

Foldable

Signature

export declare const Foldable: Foldable1<'Zipper'>

Added in v0.1.18

Functor

Signature

export declare const Functor: Functor1<'Zipper'>

Added in v0.1.18

FunctorWithIndex

Signature

export declare const FunctorWithIndex: FunctorWithIndex1<'Zipper', number>

Added in v0.1.18

Traversable

Signature

export declare const Traversable: Traversable1<'Zipper'>

Added in v0.1.18

URI

Signature

export declare const URI: 'Zipper'

Added in v0.1.6

URI (type alias)

Signature

export type URI = typeof URI

Added in v0.1.6

getMonoid

Signature

export declare const getMonoid: <A>(M: Monoid<A>) => Monoid<Zipper<A>>

Added in v0.1.6

getSemigroup

Signature

export declare const getSemigroup: <A>(S: Semigroup<A>) => Semigroup<Zipper<A>>

Added in v0.1.6

getShow

Signature

export declare const getShow: <A>(S: Show<A>) => Show<Zipper<A>>

Added in v0.1.6

zipper

Signature

export declare const zipper: Applicative1<'Zipper'> &
  Foldable1<'Zipper'> &
  Traversable1<'Zipper'> &
  Comonad1<'Zipper'> &
  FunctorWithIndex1<'Zipper', number>

Added in v0.1.6

model

Zipper (interface)

Signature

export interface Zipper<A> {
  readonly lefts: Array<A>
  readonly focus: A
  readonly rights: Array<A>
}

Added in v0.1.6

utils

findIndex

Find the first index for which a predicate holds.

Signature

export declare const findIndex: <A>(predicate: Predicate<A>) => (fa: Zipper<A>) => Option<number>

Added in v0.1.24