Identity overview

Added in v2.0.0

Table of contents

Extract

extract

Signature

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

Added in v2.6.2

constructors

of

Signature

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

Added in v2.0.0

do notation

Do

Signature

export declare const Do: {}

Added in v2.9.0

apS

Signature

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

Added in v2.8.0

bind

Signature

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

Added in v2.8.0

bindTo

Signature

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

Added in v2.8.0

let

Signature

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

Added in v2.13.0

error handling

alt

Identifies an associative operation on a type constructor. It is similar to Semigroup, except that it applies to types of kind * -> *.

Signature

export declare const alt: <A>(that: () => A) => (fa: A) => A

Added in v2.0.0

altW

Less strict version of alt.

The W suffix (short for Widening) means that the return types will be merged.

Signature

export declare const altW: <B>(that: () => B) => <A>(fa: A) => B | A

Added in v2.9.0

folding

foldMap

Signature

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

Added in v2.0.0

reduce

Signature

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

Added in v2.0.0

reduceRight

Signature

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

Added in v2.0.0

instances

Alt

Signature

export declare const Alt: Alt1<'Identity'>

Added in v2.7.0

Applicative

Signature

export declare const Applicative: Applicative1<'Identity'>

Added in v2.7.0

Apply

Signature

export declare const Apply: Apply1<'Identity'>

Added in v2.10.0

Chain

Signature

export declare const Chain: Chain1<'Identity'>

Added in v2.10.0

ChainRec

Signature

export declare const ChainRec: ChainRec1<'Identity'>

Added in v2.7.0

Comonad

Signature

export declare const Comonad: Comonad1<'Identity'>

Added in v2.7.0

Foldable

Signature

export declare const Foldable: Foldable1<'Identity'>

Added in v2.7.0

Functor

Signature

export declare const Functor: Functor1<'Identity'>

Added in v2.7.0

Monad

Signature

export declare const Monad: Monad1<'Identity'>

Added in v2.7.0

Pointed

Signature

export declare const Pointed: Pointed1<'Identity'>

Added in v2.10.0

Traversable

Signature

export declare const Traversable: Traversable1<'Identity'>

Added in v2.7.0

getEq

Signature

export declare const getEq: <A>(E: Eq<A>) => Eq<A>

Added in v2.0.0

getShow

Signature

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

Added in v2.0.0

legacy

chain

Alias of flatMap.

Signature

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

Added in v2.0.0

mapping

flap

Signature

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

Added in v2.0.0

model

Identity (type alias)

Signature

export type Identity<A> = A

Added in v2.0.0

sequencing

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) => B) => (first: A) => A

Added in v2.0.0

flatMap

Signature

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

Added in v2.14.0

flatten

Signature

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

Added in v2.0.0

traversing

sequence

Signature

export declare const sequence: Sequence1<'Identity'>

Added in v2.6.3

traverse

Signature

export declare const traverse: PipeableTraverse1<'Identity'>

Added in v2.6.3

type lambdas

URI

Signature

export declare const URI: 'Identity'

Added in v2.0.0

URI (type alias)

Signature

export type URI = typeof URI

Added in v2.0.0

utils

ap

Signature

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

Added in v2.0.0

apFirst

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

Signature

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

Added in v2.0.0

apSecond

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

Signature

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

Added in v2.0.0

duplicate

Signature

export declare const duplicate: <A>(ma: A) => A

Added in v2.0.0

extend

Signature

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

Added in v2.0.0

zone of death

identity

This instance is deprecated, use small, specific instances instead. For example if a function needs a Functor instance, pass I.Functor instead of I.identity (where I is from import I from 'fp-ts/Identity')

Signature

export declare const identity: Monad1<'Identity'> &
  Foldable1<'Identity'> &
  Traversable1<'Identity'> &
  Alt1<'Identity'> &
  Comonad1<'Identity'> &
  ChainRec1<'Identity'>

Added in v2.0.0