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Tree

Instances​

Constructors​

Do notation​

Extract​

Folding​

Legacy​

Mapping​

Model​

Sequencing​

Traversing​

Type lambdas​

Utilities​

Instances​

Applicative​

Signature​

export declare const Applicative: Applicative1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Apply​

Signature​

export declare const Apply: Apply1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Chain​

Signature​

export declare const Chain: Chain1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Comonad​

Signature​

export declare const Comonad: Comonad1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Foldable​

Signature​

export declare const Foldable: Foldable1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Functor​

Signature​

export declare const Functor: Functor1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Monad​

Signature​

export declare const Monad: Monad1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Pointed​

Signature​

export declare const Pointed: Pointed1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Traversable​

Signature​

export declare const Traversable: Traversable1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getEq​

Signature​

export declare function getEq<A>(E: Eq<A>): Eq<Tree<A>>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

getShow​

Signature​

export declare function getShow<A>(S: Show<A>): Show<Tree<A>>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Constructors​

make​

Signature​

export declare function make<A>(value: A, forest?: Forest<A>): Tree<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

of​

Signature​

export declare const of: <A>(a: A) => Tree<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

unfoldForest​

Build a (possibly infinite) forest from a list of seed values in breadth-first order.

Signature​

export declare function unfoldForest<A, B>(bs: Array<B>, f: (b: B) => [A, Array<B>]): Forest<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

unfoldForestM​

Monadic forest builder, in depth-first order

Signature​

export declare function unfoldForestM<M extends URIS4>(
  M: Monad4<M>,
): <S, R, E, A, B>(bs: Array<B>, f: (b: B) => Kind4<M, S, R, E, [A, Array<B>]>) => Kind4<M, S, R, E, Forest<A>>



export declare function unfoldForestM<M extends URIS3>(
  M: Monad3<M>,
): <R, E, A, B>(bs: Array<B>, f: (b: B) => Kind3<M, R, E, [A, Array<B>]>) => Kind3<M, R, E, Forest<A>>



export declare function unfoldForestM<M extends URIS3, E>(
  M: Monad3C<M, E>,
): <R, A, B>(bs: Array<B>, f: (b: B) => Kind3<M, R, E, [A, Array<B>]>) => Kind3<M, R, E, Forest<A>>



export declare function unfoldForestM<M extends URIS2>(
  M: Monad2<M>,
): <R, E, B>(bs: Array<B>, f: (b: B) => Kind2<M, R, [E, Array<B>]>) => Kind2<M, R, Forest<E>>



export declare function unfoldForestM<M extends URIS2, E>(
  M: Monad2C<M, E>,
): <A, B>(bs: Array<B>, f: (b: B) => Kind2<M, E, [A, Array<B>]>) => Kind2<M, E, Forest<A>>



export declare function unfoldForestM<M extends URIS>(
  M: Monad1<M>,
): <A, B>(bs: Array<B>, f: (b: B) => Kind<M, [A, Array<B>]>) => Kind<M, Forest<A>>



export declare function unfoldForestM<M>(
  M: MonadHKT<M>,
): <A, B>(bs: Array<B>, f: (b: B) => HKT<M, [A, Array<B>]>) => HKT<M, Forest<A>>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

unfoldTree​

Build a (possibly infinite) tree from a seed value in breadth-first order.

Signature​

export declare function unfoldTree<A, B>(b: B, f: (b: B) => [A, Array<B>]): Tree<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

unfoldTreeM​

Monadic tree builder, in depth-first order

Signature​

export declare function unfoldTreeM<M extends URIS4>(
  M: Monad4<M>,
): <S, R, E, A, B>(b: B, f: (b: B) => Kind4<M, S, R, E, [A, Array<B>]>) => Kind4<M, S, R, E, Tree<A>>



export declare function unfoldTreeM<M extends URIS3>(
  M: Monad3<M>,
): <R, E, A, B>(b: B, f: (b: B) => Kind3<M, R, E, [A, Array<B>]>) => Kind3<M, R, E, Tree<A>>



export declare function unfoldTreeM<M extends URIS3, E>(
  M: Monad3C<M, E>,
): <R, A, B>(b: B, f: (b: B) => Kind3<M, R, E, [A, Array<B>]>) => Kind3<M, R, E, Tree<A>>



export declare function unfoldTreeM<M extends URIS2>(
  M: Monad2<M>,
): <E, A, B>(b: B, f: (b: B) => Kind2<M, E, [A, Array<B>]>) => Kind2<M, E, Tree<A>>



export declare function unfoldTreeM<M extends URIS2, E>(
  M: Monad2C<M, E>,
): <A, B>(b: B, f: (b: B) => Kind2<M, E, [A, Array<B>]>) => Kind2<M, E, Tree<A>>



export declare function unfoldTreeM<M extends URIS>(
  M: Monad1<M>,
): <A, B>(b: B, f: (b: B) => Kind<M, [A, Array<B>]>) => Kind<M, Tree<A>>



export declare function unfoldTreeM<M>(
  M: MonadHKT<M>,
): <A, B>(b: B, f: (b: B) => HKT<M, [A, Array<B>]>) => HKT<M, Tree<A>>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Do notation​

Do​

Signature​

export declare const Do: Tree<{}>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

apS​

Signature​

export declare const apS: <N extends string, A, B>(
  name: Exclude<N, keyof A>,
  fb: Tree<B>,
) => (fa: Tree<A>) => Tree<{ readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

bind​

Signature​

export declare const bind: <N extends string, A, B>(
  name: Exclude<N, keyof A>,
  f: (a: A) => Tree<B>,
) => (ma: Tree<A>) => Tree<{ readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

bindTo​

Signature​

export declare const bindTo: <N extends string>(name: N) => <A>(fa: Tree<A>) => Tree<{ readonly [K in N]: A }>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Extract​

extract​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Folding​

fold​

Fold a tree into a "summary" value in depth-first order.

For each node in the tree, apply f to the value and the result of applying f to each forest.

This is also known as the catamorphism on trees.

Signature​

export declare function fold<A, B>(f: (a: A, bs: Array<B>) => B): (tree: Tree<A>) => B

Details​

  • Added in 0.1.0

Example​

import { fold, make } from '@fp-tx/core/Tree'
import { concatAll } from '@fp-tx/core/Monoid'
import { MonoidSum } from '@fp-tx/core/number'

const t = make(1, [make(2), make(3)])

const sum = concatAll(MonoidSum)

// Sum the values in a tree:
assert.deepStrictEqual(fold((a: number, bs: Array<number>) => a + sum(bs))(t), 6)

// Find the maximum value in the tree:
assert.deepStrictEqual(fold((a: number, bs: Array<number>) => bs.reduce((b, acc) => Math.max(b, acc), a))(t), 3)

// Count the number of leaves in the tree:
assert.deepStrictEqual(fold((_: number, bs: Array<number>) => (bs.length === 0 ? 1 : sum(bs)))(t), 2)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

foldMap​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

reduce​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

reduceRight​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Legacy​

chain​

Alias of flatMap.

Signature​

export declare const chain: <A, B>(f: (a: A) => Tree<B>) => (ma: Tree<A>) => Tree<B>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Mapping​

flap​

Signature​

export declare const flap: <A>(a: A) => <B>(fab: Tree<(a: A) => B>) => Tree<B>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

map​

map can be used to turn functions (a: A) => B into functions (fa: F<A>) => F<B> whose argument and return types use the type constructor F to represent some computational context.

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Model​

Forest​

Signature​

export type Forest<A> = Array<Tree<A>>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Tree​

Signature​

export interface Tree<A> {
  readonly forest: Forest<A>
  readonly value: A
}

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Sequencing​

flatMap​

Signature​

export declare const flatMap: {
  <A, B>(f: (a: A) => Tree<B>): (ma: Tree<A>) => Tree<B>
  <A, B>(ma: Tree<A>, f: (a: A) => Tree<B>): Tree<B>
}

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

flatten​

Signature​

export declare const flatten: <A>(mma: Tree<Tree<A>>) => Tree<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Traversing​

sequence​

Signature​

export declare const sequence: Traversable1<URI>['sequence']

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

traverse​

Signature​

export declare const traverse: PipeableTraverse1<URI>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Type lambdas​

URI​

Signature​

export type URI = typeof URI

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

URI​

Signature​

export declare const URI = 'Tree'

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

Utilities​

ap​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

apFirst​

Combine two effectful actions, keeping only the result of the first.

Signature​

export declare const apFirst: <B>(second: Tree<B>) => <A>(first: Tree<A>) => Tree<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

apSecond​

Combine two effectful actions, keeping only the result of the second.

Signature​

export declare const apSecond: <B>(second: Tree<B>) => <A>(first: Tree<A>) => Tree<B>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

chainFirst​

Composes computations in sequence, using the return value of one computation to determine the next computation and keeping only the result of the first.

Signature​

export declare const chainFirst: <A, B>(f: (a: A) => Tree<B>) => (first: Tree<A>) => Tree<A>

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

drawForest​

Neat 2-dimensional drawing of a forest

Signature​

export declare function drawForest(forest: Forest<string>): string

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

drawTree​

Neat 2-dimensional drawing of a tree

Signature​

export declare function drawTree(tree: Tree<string>): string

Details​

  • Added in 0.1.0

Example​

import { make, drawTree } from '@fp-tx/core/Tree'

const fa = make('a', [make('b'), make('c'), make('d', [make('e'), make('f')])])

assert.strictEqual(
  drawTree(fa),
  `a
├─ b
├─ c
└─ d
├─ e
└─ f`,
)

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

duplicate​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

elem​

Signature​

export declare function elem<A>(E: Eq<A>): (a: A, fa: Tree<A>) => boolean

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

exists​

Signature​

export declare const exists: <A>(predicate: Predicate<A>) => (ma: Tree<A>) => boolean

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

extend​

Signature​

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

Details​

  • Added in 0.1.0

License​

  • MIT – Copyright (c) 2017-present Giulio Canti

let​

Signature​

export declare const let_: <N extends string, A, B>(
  name: Exclude<N, keyof A>,
  f: (a: A) => B,
) => (fa: Tree<A>) => Tree<{ readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>

tree​

This instance is deprecated, use small, specific instances instead. For example if a function needs a Functor instance, pass T.Functor instead of T.tree (where T is from import T from 'fp-ts/Tree')

Signature​

export declare const tree: Monad1<URI> & Foldable1<URI> & Traversable1<URI> & Comonad1<URI>

Details​

  • Added in 0.1.0
  • Deprecated

License​

  • MIT – Copyright (c) 2017-present Giulio Canti