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Io

Instances​

Combinators​

Constructors​

Do notation​

Instance Methods​

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: chainable.Chain1<URI>

Details​

  • Added in 0.1.0

License​

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

ChainRec​

Signature​

export declare const ChainRec: ChainRec1<URI>

Details​

  • Added in 0.1.0

License​

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

FromIO​

Signature​

export declare const FromIO: FromIO1<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

MonadIO​

Signature​

export declare const MonadIO: MonadIO1<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

Combinators​

tap​

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 tap: {
  <A, _>(self: IO<A>, f: (a: A) => IO<_>): IO<A>
  <A, _>(f: (a: A) => IO<_>): (self: IO<A>) => IO<A>
}

Details​

  • Added in 0.1.0

License​

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

Constructors​

of​

Signature​

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

Details​

  • Added in 0.1.0

License​

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

Do notation​

Do​

Signature​

export declare const Do: IO<{}>

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: IO<B>,
) => (fa: IO<A>) => IO<{ 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) => IO<B>,
) => (ma: IO<A>) => IO<{ 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: IO<A>) => IO<{ readonly [K in N]: A }>

Details​

  • Added in 0.1.0

License​

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

Instance Methods​

chainRec​

Signature​

export declare const chainRec: ChainRec1<URI>['chainRec']

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) => IO<B>) => (ma: IO<A>) => IO<B>

Details​

  • Added in 0.1.0

License​

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

chainFirst​

Alias of tap.

Signature​

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

Details​

  • Added in 0.1.0

License​

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

Mapping​

as​

Maps the value to the specified constant value.

Signature​

export declare const as: {
  <A>(a: A): <_>(self: IO<_>) => IO<A>
  <_, A>(self: IO<_>, a: A): IO<A>
}

Details​

  • Added in 0.1.0

License​

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

asUnit​

Maps the value to the void constant value.

Signature​

export declare const asUnit: <_>(self: IO<_>) => IO<void>

Details​

  • Added in 0.1.0

License​

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

flap​

Signature​

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

Details​

  • Added in 0.1.0

License​

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

Model​

IO​

Signature​

export interface IO<A> {
  (): 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) => IO<B>): (ma: IO<A>) => IO<B>
  <A, B>(ma: IO<A>, f: (a: A) => IO<B>): IO<B>
}

Details​

  • Added in 0.1.0

License​

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

flatten​

Signature​

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

Details​

  • Added in 0.1.0

License​

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

Traversing​

sequenceArray​

Equivalent to ReadonlyArray#sequence(Applicative).

Signature​

export declare const sequenceArray: <A>(arr: ReadonlyArray<IO<A>>) => IO<ReadonlyArray<A>>

Details​

  • Added in 0.1.0

License​

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

traverseArray​

Equivalent to ReadonlyArray#traverse(Applicative).

Signature​

export declare const traverseArray: <A, B>(f: (a: A) => IO<B>) => (as: readonly A[]) => IO<readonly B[]>

Details​

  • Added in 0.1.0

License​

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

traverseArrayWithIndex​

Equivalent to ReadonlyArray#traverseWithIndex(Applicative).

Signature​

export declare const traverseArrayWithIndex: <A, B>(
  f: (index: number, a: A) => IO<B>,
) => (as: ReadonlyArray<A>) => IO<ReadonlyArray<B>>

Details​

  • Added in 0.1.0

License​

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

traverseReadonlyArrayWithIndex​

Equivalent to ReadonlyArray#traverseWithIndex(Applicative).

Signature​

export declare const traverseReadonlyArrayWithIndex: <A, B>(
  f: (index: number, a: A) => IO<B>,
) => (as: readonly A[]) => IO<readonly B[]>

Details​

  • Added in 0.1.0

License​

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

traverseReadonlyNonEmptyArrayWithIndex​

Equivalent to ReadonlyNonEmptyArray#traverseWithIndex(Applicative).

Signature​

export declare const traverseReadonlyNonEmptyArrayWithIndex: <A, B>(
  f: (index: number, a: A) => IO<B>,
) => (as: ReadonlyNonEmptyArray<A>) => IO<ReadonlyNonEmptyArray<B>>

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 = 'IO'

Details​

  • Added in 0.1.0

License​

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

Utilities​

ApT​

Signature​

export declare const ApT: IO<readonly []>

Details​

  • Added in 0.1.0

License​

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

ap​

Signature​

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

Details​

  • Added in 0.1.0

License​

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

do​

Signature​

export declare const do_: <MA extends IOIterable<any>, A>(
  yieldFunction: (unwrap: <A>(ma: IO<A>) => IOIterable<A>) => Generator<MA, A>,
) => IO<A>

fromIO​

Signature​

export declare const fromIO: <A>(fa: IO<A>) => IO<A>

Details​

  • Added in 0.1.0
  • Deprecated

License​

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

getMonoid​

Use getApplicativeMonoid instead.

Signature​

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

Details​

  • Added in 0.1.0
  • Deprecated

License​

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

getSemigroup​

Use getApplySemigroup instead.

Signature​

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

Details​

  • Added in 0.1.0
  • Deprecated

License​

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

io​

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

Signature​

export declare const io: Monad1<URI> & MonadIO1<URI> & ChainRec1<URI>

Details​

  • Added in 0.1.0
  • Deprecated

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: IO<A>) => IO<{ readonly [K in N | keyof A]: K extends keyof A ? A[K] : B }>