Writer overview

Added in v2.0.0

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Table of contents

• constructors
  • tell
• instances
  • Functor
  • getApplicative
  • getApply
  • getChain
  • getMonad
  • getPointed
• mapping
  • flap
  • map
• model
  • Writer (interface)
• type lambdas
  • URI
  • URI (type alias)
• utils
  • censor
  • evaluate
  • execute
  • listen
  • listens
  • pass
• zone of death
  • evalWriter
  • execWriter
  • writer

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constructors

tell

Appends a value to the accumulator

Signature

export declare const tell: <W>(w: W) => Writer<W, void>

Added in v2.0.0

instances

Functor

Signature

export declare const Functor: Functor2<'Writer'>

Added in v2.7.0

getApplicative

Signature

export declare const getApplicative: <W>(M: Monoid<W>) => Applicative2C<'Writer', W>

Added in v2.10.0

getApply

Signature

export declare const getApply: <W>(S: Semigroup<W>) => Apply2C<'Writer', W>

Added in v2.10.0

getChain

Signature

export declare function getChain<W>(S: Semigroup<W>): Chain2C<URI, W>

Added in v2.10.0

getMonad

Signature

export declare function getMonad<W>(M: Monoid<W>): Monad2C<URI, W>

Added in v2.0.0

getPointed

Signature

export declare const getPointed: <W>(M: Monoid<W>) => Pointed2C<'Writer', W>

Added in v2.10.0

mapping

flap

Signature

export declare const flap: <A>(a: A) => <E, B>(fab: Writer<E, (a: A) => B>) => Writer<E, B>

Added in v2.10.0

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) => <E>(fa: Writer<E, A>) => Writer<E, B>

Added in v2.0.0

model

Writer (interface)

Signature

export interface Writer<W, A> {
  (): [A, W]
}

Added in v2.0.0

type lambdas

URI

Signature

export declare const URI: 'Writer'

Added in v2.0.0

URI (type alias)

Signature

export type URI = typeof URI

Added in v2.0.0

utils

censor

Modify the final accumulator value by applying a function

Signature

export declare const censor: <W>(f: (w: W) => W) => <A>(fa: Writer<W, A>) => Writer<W, A>

Added in v2.0.0

evaluate

Signature

export declare const evaluate: <W, A>(fa: Writer<W, A>) => A

Added in v2.8.0

execute

Signature

export declare const execute: <W, A>(fa: Writer<W, A>) => W

Added in v2.8.0

listen

Modifies the result to include the changes to the accumulator

Signature

export declare const listen: <W, A>(fa: Writer<W, A>) => Writer<W, [A, W]>

Added in v2.0.0

listens

Projects a value from modifications made to the accumulator during an action

Signature

export declare const listens: <W, B>(f: (w: W) => B) => <A>(fa: Writer<W, A>) => Writer<W, [A, B]>

Added in v2.0.0

pass

Applies the returned function to the accumulator

Signature

export declare const pass: <W, A>(fa: Writer<W, [A, (w: W) => W]>) => Writer<W, A>

Added in v2.0.0

zone of death

evalWriter

Use evaluate instead

Signature

export declare const evalWriter: <W, A>(fa: Writer<W, A>) => A

Added in v2.0.0

execWriter

Use execute instead

Signature

export declare const execWriter: <W, A>(fa: Writer<W, A>) => W

Added in v2.0.0

writer

Use Functor instead.

Signature

export declare const writer: Functor2<'Writer'>

Added in v2.0.0