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Effect overview

Added in v1.0.0

Table of contents

alternatives

orDie

Translates effect failure into death of the fiber, making all failures unchecked and not a part of the type of the effect.

Signature

export declare const orDie: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, A>

Added in v1.0.0

orDieWith

Keeps none of the errors, and terminates the fiber with them, using the specified function to convert the E into a Throwable.

Signature

export declare const orDieWith: {
  <E>(f: (error: E) => unknown): <R, A>(self: Effect<R, E, A>) => Effect<R, never, A>
  <R, E, A>(self: Effect<R, E, A>, f: (error: E) => unknown): Effect<R, never, A>
}

Added in v1.0.0

orElse

Executes this effect and returns its value, if it succeeds, but otherwise executes the specified effect.

Signature

export declare const orElse: {
  <R2, E2, A2>(that: LazyArg<Effect<R2, E2, A2>>): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2, A2 | A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, that: LazyArg<Effect<R2, E2, A2>>): Effect<R | R2, E2, A | A2>
}

Added in v1.0.0

orElseFail

Executes this effect and returns its value, if it succeeds, but otherwise fails with the specified error.

Signature

export declare const orElseFail: {
  <E2>(evaluate: LazyArg<E2>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E2, A>
  <R, E, A, E2>(self: Effect<R, E, A>, evaluate: LazyArg<E2>): Effect<R, E2, A>
}

Added in v1.0.0

orElseSucceed

Executes this effect and returns its value, if it succeeds, but otherwise succeeds with the specified value.

Signature

export declare const orElseSucceed: {
  <A2>(evaluate: LazyArg<A2>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, A2 | A>
  <R, E, A, A2>(self: Effect<R, E, A>, evaluate: LazyArg<A2>): Effect<R, never, A | A2>
}

Added in v1.0.0

caching

cached

Returns an effect that, if evaluated, will return the lazily computed result of this effect.

Signature

export declare const cached: <R, E, A>(self: Effect<R, E, A>) => Effect<never, never, Effect<R, E, A>>

Added in v1.0.0

cachedFunction

Returns a memoized version of the specified effectual function.

Signature

export declare const cachedFunction: <R, E, A, B>(
  f: (a: A) => Effect<R, E, B>,
  eq?: Equivalence<A> | undefined
) => Effect<never, never, (a: A) => Effect<R, E, B>>

Added in v1.0.0

cachedInvalidateWithTTL

Returns an effect that, if evaluated, will return the cached result of this effect. Cached results will expire after timeToLive duration. In addition, returns an effect that can be used to invalidate the current cached value before the timeToLive duration expires.

Signature

export declare const cachedInvalidateWithTTL: {
  (timeToLive: Duration.DurationInput): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R, never, [Effect<never, E, A>, Effect<never, never, void>]>
  <R, E, A>(self: Effect<R, E, A>, timeToLive: Duration.DurationInput): Effect<
    R,
    never,
    [Effect<never, E, A>, Effect<never, never, void>]
  >
}

Added in v1.0.0

cachedWithTTL

Returns an effect that, if evaluated, will return the cached result of this effect. Cached results will expire after timeToLive duration.

Signature

export declare const cachedWithTTL: {
  (timeToLive: Duration.DurationInput): <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Effect<never, E, A>>
  <R, E, A>(self: Effect<R, E, A>, timeToLive: Duration.DurationInput): Effect<R, never, Effect<never, E, A>>
}

Added in v1.0.0

once

Returns an effect that will be executed at most once, even if it is evaluated multiple times.

Signature

export declare const once: <R, E, A>(self: Effect<R, E, A>) => Effect<never, never, Effect<R, E, void>>

Added in v1.0.0

clock

clock

Retreives the Clock service from the context

Signature

export declare const clock: Effect<never, never, Clock.Clock>

Added in v1.0.0

clockWith

Retreives the Clock service from the context and provides it to the specified effectful function.

Signature

export declare const clockWith: <R, E, A>(f: (clock: Clock.Clock) => Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

setClock

Signature

export declare const setClock: <A extends Clock.Clock>(clock: A) => Layer.Layer<never, never, never>

Added in v1.0.0

withClock

Executes the specified workflow with the specified implementation of the clock service.

Signature

export declare const withClock: {
  <A extends Clock.Clock>(value: A): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A extends Clock.Clock>(effect: Effect<R, E, A>, value: A): Effect<R, E, A>
}

Added in v1.0.0

collecting & elements

all

Runs all the provided effects in sequence respecting the structure provided in input.

Supports multiple arguments, a single argument tuple / array or record / struct.

Signature

export declare const all: <
  const Arg extends Iterable<Effect<any, any, any>> | Record<string, Effect<any, any, any>>,
  O extends {
    readonly concurrency?: Concurrency | undefined
    readonly batching?: boolean | 'inherit' | undefined
    readonly discard?: boolean | undefined
    readonly mode?: 'default' | 'validate' | 'either' | undefined
  }
>(
  arg: Arg,
  options?: O | undefined
) => All.Return<Arg, O>

Added in v1.0.0

allSuccesses

Evaluate and run each effect in the structure and collect the results, discarding results from failed effects.

Signature

export declare const allSuccesses: <R, E, A>(
  elements: Iterable<Effect<R, E, A>>,
  options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
) => Effect<R, never, A[]>

Added in v1.0.0

allWith

Data-last variant of Effect.all.

Runs all the provided effects in sequence respecting the structure provided in input.

Supports multiple arguments, a single argument tuple / array or record / struct.

Signature

export declare const allWith: <
  O extends {
    readonly concurrency?: Concurrency | undefined
    readonly batching?: boolean | 'inherit' | undefined
    readonly discard?: boolean | undefined
    readonly mode?: 'default' | 'validate' | 'either' | undefined
  }
>(
  options?: O | undefined
) => <const Arg extends Iterable<Effect<any, any, any>> | Record<string, Effect<any, any, any>>>(
  arg: Arg
) => All.Return<Arg, O>

Added in v1.0.0

dropUntil

Drops all elements until the effectful predicate returns true.

Signature

export declare const dropUntil: {
  <A, R, E>(predicate: (a: A, i: number) => Effect<R, E, boolean>): (elements: Iterable<A>) => Effect<R, E, A[]>
  <A, R, E>(elements: Iterable<A>, predicate: (a: A, i: number) => Effect<R, E, boolean>): Effect<R, E, A[]>
}

Added in v1.0.0

dropWhile

Drops all elements so long as the predicate returns true.

Signature

export declare const dropWhile: {
  <R, E, A>(f: (a: A, i: number) => Effect<R, E, boolean>): (elements: Iterable<A>) => Effect<R, E, A[]>
  <R, E, A>(elements: Iterable<A>, f: (a: A, i: number) => Effect<R, E, boolean>): Effect<R, E, A[]>
}

Added in v1.0.0

every

Determines whether all elements of the Collection<A> satisfies the effectual predicate f.

Signature

export declare const every: {
  <R, E, A>(f: (a: A, i: number) => Effect<R, E, boolean>): (elements: Iterable<A>) => Effect<R, E, boolean>
  <R, E, A>(elements: Iterable<A>, f: (a: A, i: number) => Effect<R, E, boolean>): Effect<R, E, boolean>
}

Added in v1.0.0

exists

Determines whether any element of the Iterable<A> satisfies the effectual predicate f.

Signature

export declare const exists: {
  <R, E, A>(
    f: (a: A, i: number) => Effect<R, E, boolean>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): (elements: Iterable<A>) => Effect<R, E, boolean>
  <R, E, A>(
    elements: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, boolean>,
    options?: { readonly concurrency: Concurrency; readonly batching?: boolean | 'inherit' }
  ): Effect<R, E, boolean>
}

Added in v1.0.0

filter

Filters the collection using the specified effectful predicate.

Signature

export declare const filter: {
  <A, R, E>(
    f: (a: A, i: number) => Effect<R, E, boolean>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly negate?: boolean }
  ): (elements: Iterable<A>) => Effect<R, E, A[]>
  <A, R, E>(
    elements: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, boolean>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly negate?: boolean }
  ): Effect<R, E, A[]>
}

Added in v1.0.0

findFirst

Returns the first element that satisfies the effectful predicate.

Signature

export declare const findFirst: {
  <A, R, E>(f: (a: A, i: number) => Effect<R, E, boolean>): (elements: Iterable<A>) => Effect<R, E, Option.Option<A>>
  <A, R, E>(elements: Iterable<A>, f: (a: A, i: number) => Effect<R, E, boolean>): Effect<R, E, Option.Option<A>>
}

Added in v1.0.0

firstSuccessOf

This function takes an iterable of Effect values and returns a new Effect value that represents the first Effect value in the iterable that succeeds. If all of the Effect values in the iterable fail, then the resulting Effect value will fail as well.

This function is sequential, meaning that the Effect values in the iterable will be executed in sequence, and the first one that succeeds will determine the outcome of the resulting Effect value.

Signature

export declare const firstSuccessOf: <R, E, A>(effects: Iterable<Effect<R, E, A>>) => Effect<R, E, A>

Added in v1.0.0

forEach

Signature

export declare const forEach: {
  <A, R, E, B>(
    f: (a: A, i: number) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard?: false }
  ): (self: Iterable<A>) => Effect<R, E, B[]>
  <A, R, E, B>(
    f: (a: A, i: number) => Effect<R, E, B>,
    options: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard: true }
  ): (self: Iterable<A>) => Effect<R, E, void>
  <A, R, E, B>(
    self: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard?: false }
  ): Effect<R, E, B[]>
  <A, R, E, B>(
    self: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, B>,
    options: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard: true }
  ): Effect<R, E, void>
}

Added in v1.0.0

Returns a successful effect with the head of the collection if the collection is non-empty, or fails with the error None if the collection is empty.

Signature

export declare const head: <R, E, A>(self: Effect<R, E, Iterable<A>>) => Effect<R, Option.Option<E>, A>

Added in v1.0.0

mergeAll

Merges an Iterable<Effect<R, E, A>> to a single effect, working sequentially.

Signature

export declare const mergeAll: {
  <Z, A>(
    zero: Z,
    f: (z: Z, a: A, i: number) => Z,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): <R, E>(elements: Iterable<Effect<R, E, A>>) => Effect<R, E, Z>
  <R, E, A, Z>(
    elements: Iterable<Effect<R, E, A>>,
    zero: Z,
    f: (z: Z, a: A, i: number) => Z,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): Effect<R, E, Z>
}

Added in v1.0.0

partition

Feeds elements of type A to a function f that returns an effect. Collects all successes and failures in a tupled fashion.

Signature

export declare const partition: {
  <R, E, A, B>(
    f: (a: A) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): (elements: Iterable<A>) => Effect<R, never, readonly [E[], B[]]>
  <R, E, A, B>(
    elements: Iterable<A>,
    f: (a: A) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): Effect<R, never, readonly [E[], B[]]>
}

Added in v1.0.0

reduce

Folds an Iterable<A> using an effectual function f, working sequentially from left to right.

Signature

export declare const reduce: {
  <Z, A, R, E>(zero: Z, f: (z: Z, a: A, i: number) => Effect<R, E, Z>): (elements: Iterable<A>) => Effect<R, E, Z>
  <Z, A, R, E>(elements: Iterable<A>, zero: Z, f: (z: Z, a: A, i: number) => Effect<R, E, Z>): Effect<R, E, Z>
}

Added in v1.0.0

reduceEffect

Reduces an Iterable<Effect<R, E, A>> to a single effect.

Signature

export declare const reduceEffect: {
  <R, E, A>(
    zero: Effect<R, E, A>,
    f: (acc: A, a: A, i: number) => A,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): (elements: Iterable<Effect<R, E, A>>) => Effect<R, E, A>
  <R, E, A>(
    elements: Iterable<Effect<R, E, A>>,
    zero: Effect<R, E, A>,
    f: (acc: A, a: A, i: number) => A,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): Effect<R, E, A>
}

Added in v1.0.0

reduceRight

Folds an Iterable<A> using an effectual function f, working sequentially from left to right.

Signature

export declare const reduceRight: {
  <A, Z, R, E>(zero: Z, f: (a: A, z: Z, i: number) => Effect<R, E, Z>): (elements: Iterable<A>) => Effect<R, E, Z>
  <A, Z, R, E>(elements: Iterable<A>, zero: Z, f: (a: A, z: Z, i: number) => Effect<R, E, Z>): Effect<R, E, Z>
}

Added in v1.0.0

reduceWhile

Folds over the elements in this chunk from the left, stopping the fold early when the predicate is not satisfied.

Signature

export declare const reduceWhile: {
  <A, R, E, Z>(
    zero: Z,
    options: { readonly while: Predicate<Z>; readonly body: (s: Z, a: A, i: number) => Effect<R, E, Z> }
  ): (elements: Iterable<A>) => Effect<R, E, Z>
  <A, R, E, Z>(
    elements: Iterable<A>,
    zero: Z,
    options: { readonly while: Predicate<Z>; readonly body: (s: Z, a: A, i: number) => Effect<R, E, Z> }
  ): Effect<R, E, Z>
}

Added in v1.0.0

replicate

Replicates the given effect n times.

Signature

export declare const replicate: {
  (n: number): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>[]
  <R, E, A>(self: Effect<R, E, A>, n: number): Effect<R, E, A>[]
}

Added in v1.0.0

replicateEffect

Performs this effect the specified number of times and collects the results.

Signature

export declare const replicateEffect: {
  (
    n: number,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard?: false }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A[]>
  (
    n: number,
    options: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard: true }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, void>
  <R, E, A>(
    self: Effect<R, E, A>,
    n: number,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard?: false }
  ): Effect<R, E, A[]>
  <R, E, A>(
    self: Effect<R, E, A>,
    n: number,
    options: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard: true }
  ): Effect<R, E, void>
}

Added in v1.0.0

takeUntil

Takes elements until the effectual predicate returns true.

Signature

export declare const takeUntil: {
  <R, E, A>(predicate: (a: A, i: number) => Effect<R, E, boolean>): (elements: Iterable<A>) => Effect<R, E, A[]>
  <R, E, A>(elements: Iterable<A>, predicate: (a: A, i: number) => Effect<R, E, boolean>): Effect<R, E, A[]>
}

Added in v1.0.0

takeWhile

Takes all elements so long as the effectual predicate returns true.

Signature

export declare const takeWhile: {
  <R, E, A>(predicate: (a: A, i: number) => Effect<R, E, boolean>): (elements: Iterable<A>) => Effect<R, E, A[]>
  <R, E, A>(elements: Iterable<A>, predicate: (a: A, i: number) => Effect<R, E, boolean>): Effect<R, E, A[]>
}

Added in v1.0.0

validateAll

Feeds elements of type A to f and accumulates all errors in error channel or successes in success channel.

This combinator is lossy meaning that if there are errors all successes will be lost. To retain all information please use partition.

Signature

export declare const validateAll: {
  <R, E, A, B>(
    f: (a: A, i: number) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard?: false }
  ): (elements: Iterable<A>) => Effect<R, E[], B[]>
  <R, E, A, B>(
    f: (a: A, i: number) => Effect<R, E, B>,
    options: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard: true }
  ): (elements: Iterable<A>) => Effect<R, E[], void>
  <R, E, A, B>(
    elements: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard?: false }
  ): Effect<R, E[], B[]>
  <R, E, A, B>(
    elements: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, B>,
    options: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit'; readonly discard: true }
  ): Effect<R, E[], void>
}

Added in v1.0.0

validateFirst

Feeds elements of type A to f until it succeeds. Returns first success or the accumulation of all errors.

If elements is empty then Effect.fail([]) is returned.

Signature

export declare const validateFirst: {
  <R, E, A, B>(
    f: (a: A, i: number) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): (elements: Iterable<A>) => Effect<R, E[], B>
  <R, E, A, B>(
    elements: Iterable<A>,
    f: (a: A, i: number) => Effect<R, E, B>,
    options?: { readonly concurrency?: Concurrency; readonly batching?: boolean | 'inherit' }
  ): Effect<R, E[], B>
}

Example

import * as Effect from '@effect/io/Effect'
import * as Exit from '@effect/io/Exit'

const f = (n: number) => (n > 0 ? Effect.succeed(n) : Effect.fail(`${n} is negative`))

assert.deepStrictEqual(Effect.runSyncExit(Effect.validateFirst([], f)), Exit.fail([]))
assert.deepStrictEqual(Effect.runSyncExit(Effect.validateFirst([1, 2], f)), Exit.succeed(1))
assert.deepStrictEqual(Effect.runSyncExit(Effect.validateFirst([1, -1], f)), Exit.succeed(1))
assert.deepStrictEqual(Effect.runSyncExit(Effect.validateFirst([-1, 2], f)), Exit.succeed(2))
assert.deepStrictEqual(
  Effect.runSyncExit(Effect.validateFirst([-1, -2], f)),
  Exit.fail(['-1 is negative', '-2 is negative'])
)

Added in v1.0.0

config

config

Uses the default config provider to load the specified config, or fail with an error of type Config.Error.

Signature

export declare const config: <A>(config: Config<A>) => Effect<never, ConfigError, A>

Added in v1.0.0

configProviderWith

Retrieves the default config provider, and passes it to the specified function, which may return an effect that uses the provider to perform some work or compute some value.

Signature

export declare const configProviderWith: <R, E, A>(
  f: (configProvider: ConfigProvider) => Effect<R, E, A>
) => Effect<R, E, A>

Added in v1.0.0

setConfigProvider

Sets the current ConfigProvider.

Signature

export declare const setConfigProvider: (configProvider: ConfigProvider) => Layer.Layer<never, never, never>

Added in v1.0.0

withConfigProvider

Executes the specified workflow with the specified configuration provider.

Signature

export declare const withConfigProvider: {
  (value: ConfigProvider): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, value: ConfigProvider): Effect<R, E, A>
}

Added in v1.0.0

withConfigProviderScoped

Sets the configuration provider to the specified value and restores it to its original value when the scope is closed.

Signature

export declare const withConfigProviderScoped: (value: ConfigProvider) => Effect<Scope.Scope, never, void>

Added in v1.0.0

constructors

async

Imports an asynchronous side-effect into a pure Effect value. The callback function Effect<R, E, A> => void must be called at most once.

If an Effect is returned by the registration function, it will be executed if the fiber executing the effect is interrupted.

The registration function can also receive an AbortSignal if required for interruption.

The FiberId of the fiber that may complete the async callback may be provided to allow for better diagnostics.

Signature

export declare const async: <R, E, A>(
  register: (callback: (_: Effect<R, E, A>) => void, signal: AbortSignal) => void | Effect<R, never, void>,
  blockingOn?: FiberId.FiberId
) => Effect<R, E, A>

Added in v1.0.0

asyncEffect

Converts an asynchronous, callback-style API into an Effect, which will be executed asynchronously.

With this variant, the registration function may return a an Effect.

Signature

export declare const asyncEffect: <R, E, A, R2, E2, X>(
  register: (callback: (_: Effect<R, E, A>) => void) => Effect<R2, E2, X>
) => Effect<R | R2, E | E2, A>

Added in v1.0.0

asyncEither

Imports an asynchronous side-effect into an effect. It has the option of returning the value synchronously, which is useful in cases where it cannot be determined if the effect is synchronous or asynchronous until the register is actually executed. It also has the option of returning a canceler, which will be used by the runtime to cancel the asynchronous effect if the fiber executing the effect is interrupted.

If the register function returns a value synchronously, then the callback function Effect<R, E, A> => void must not be called. Otherwise the callback function must be called at most once.

The FiberId of the fiber that may complete the async callback may be provided to allow for better diagnostics.

Signature

export declare const asyncEither: <R, E, A>(
  register: (callback: (effect: Effect<R, E, A>) => void) => Either.Either<Effect<R, never, void>, Effect<R, E, A>>,
  blockingOn?: FiberId.FiberId
) => Effect<R, E, A>

Added in v1.0.0

asyncOption

Imports an asynchronous effect into a pure Effect value, possibly returning the value synchronously.

If the register function returns a value synchronously, then the callback function Effect<R, E, A> => void must not be called. Otherwise the callback function must be called at most once.

The FiberId of the fiber that may complete the async callback may be provided to allow for better diagnostics.

Signature

export declare const asyncOption: <R, E, A>(
  register: (callback: (_: Effect<R, E, A>) => void) => Option.Option<Effect<R, E, A>>,
  blockingOn?: FiberId.FiberId
) => Effect<R, E, A>

Added in v1.0.0

die

Signature

export declare const die: (defect: unknown) => Effect<never, never, never>

Added in v1.0.0

dieMessage

Returns an effect that dies with a RuntimeException having the specified text message. This method can be used for terminating a fiber because a defect has been detected in the code.

Signature

export declare const dieMessage: (message: string) => Effect<never, never, never>

Added in v1.0.0

dieSync

Signature

export declare const dieSync: (evaluate: LazyArg<unknown>) => Effect<never, never, never>

Added in v1.0.0

fail

Signature

export declare const fail: <E>(error: E) => Effect<never, E, never>

Added in v1.0.0

failCause

Signature

export declare const failCause: <E>(cause: Cause.Cause<E>) => Effect<never, E, never>

Added in v1.0.0

failCauseSync

Signature

export declare const failCauseSync: <E>(evaluate: LazyArg<Cause.Cause<E>>) => Effect<never, E, never>

Added in v1.0.0

failSync

Signature

export declare const failSync: <E>(evaluate: LazyArg<E>) => Effect<never, E, never>

Added in v1.0.0

gen

Signature

export declare const gen: <Eff extends EffectGen<any, any, any>, AEff>(
  f: (resume: Adapter) => Generator<Eff, AEff, any>
) => Effect<
  [Eff] extends [never] ? never : [Eff] extends [EffectGen<infer R, any, any>] ? R : never,
  [Eff] extends [never] ? never : [Eff] extends [EffectGen<any, infer E, any>] ? E : never,
  AEff
>

Added in v1.0.0

never

Returns a effect that will never produce anything. The moral equivalent of while(true) {}, only without the wasted CPU cycles.

Signature

export declare const never: Effect<never, never, never>

Added in v1.0.0

none

Requires the option produced by this value to be None.

Signature

export declare const none: <R, E, A>(self: Effect<R, E, Option.Option<A>>) => Effect<R, Option.Option<E>, void>

Added in v1.0.0

promise

Like tryPromise but produces a defect in case of errors.

An optional AbortSignal can be provided to allow for interruption of the wrapped Promise api.

Signature

export declare const promise: <A>(evaluate: (signal: AbortSignal) => Promise<A>) => Effect<never, never, A>

Added in v1.0.0

succeed

Signature

export declare const succeed: <A>(value: A) => Effect<never, never, A>

Added in v1.0.0

succeedNone

Returns an effect which succeeds with None.

Signature

export declare const succeedNone: Effect<never, never, Option.Option<never>>

Added in v1.0.0

succeedSome

Returns an effect which succeeds with the value wrapped in a Some.

Signature

export declare const succeedSome: <A>(value: A) => Effect<never, never, Option.Option<A>>

Added in v1.0.0

suspend

Signature

export declare const suspend: <R, E, A>(effect: LazyArg<Effect<R, E, A>>) => Effect<R, E, A>

Added in v1.0.0

sync

Signature

export declare const sync: <A>(evaluate: LazyArg<A>) => Effect<never, never, A>

Added in v1.0.0

unit

Signature

export declare const unit: Effect<never, never, void>

Added in v1.0.0

withClockScoped

Sets the implementation of the clock service to the specified value and restores it to its original value when the scope is closed.

Signature

export declare const withClockScoped: <A extends Clock.Clock>(value: A) => Effect<Scope.Scope, never, void>

Added in v1.0.0

yieldNow

Signature

export declare const yieldNow: (options?: { readonly priority?: number }) => Effect<never, never, void>

Added in v1.0.0

context

context

Signature

export declare const context: <R>() => Effect<R, never, Context.Context<R>>

Added in v1.0.0

contextWith

Accesses the context of the effect.

Signature

export declare const contextWith: <R, A>(f: (context: Context.Context<R>) => A) => Effect<R, never, A>

Added in v1.0.0

contextWithEffect

Effectually accesses the context of the effect.

Signature

export declare const contextWithEffect: <R, R0, E, A>(
  f: (context: Context.Context<R0>) => Effect<R, E, A>
) => Effect<R | R0, E, A>

Added in v1.0.0

mapInputContext

Provides some of the context required to run this effect, leaving the remainder R0.

Signature

export declare const mapInputContext: {
  <R0, R>(f: (context: Context.Context<R0>) => Context.Context<R>): <E, A>(self: Effect<R, E, A>) => Effect<R0, E, A>
  <R0, R, E, A>(self: Effect<R, E, A>, f: (context: Context.Context<R0>) => Context.Context<R>): Effect<R0, E, A>
}

Added in v1.0.0

provide

Splits the context into two parts, providing one part using the specified layer/context/runtime and leaving the remainder R0.

Signature

export declare const provide: {
  <R2, E2, A2>(layer: Layer.Layer<R2, E2, A2>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | Exclude<R, A2>, E2 | E, A>
  <R2>(context: Context.Context<R2>): <R, E, A>(self: Effect<R, E, A>) => Effect<Exclude<R, R2>, E, A>
  <R2>(runtime: Runtime.Runtime<R2>): <R, E, A>(self: Effect<R, E, A>) => Effect<Exclude<R, R2>, E, A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, layer: Layer.Layer<R2, E2, A2>): Effect<R2 | Exclude<R, A2>, E | E2, A>
  <R, E, A, R2>(self: Effect<R, E, A>, context: Context.Context<R2>): Effect<Exclude<R, R2>, E, A>
  <R, E, A, R2>(self: Effect<R, E, A>, runtime: Runtime.Runtime<R2>): Effect<Exclude<R, R2>, E, A>
}

Added in v1.0.0

provideService

Provides the effect with the single service it requires. If the effect requires more than one service use provideContext instead.

Signature

export declare const provideService: {
  <T extends Context.Tag<any, any>>(tag: T, service: Context.Tag.Service<T>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<Exclude<R, Context.Tag.Identifier<T>>, E, A>
  <R, E, A, T extends Context.Tag<any, any>>(self: Effect<R, E, A>, tag: T, service: Context.Tag.Service<T>): Effect<
    Exclude<R, Context.Tag.Identifier<T>>,
    E,
    A
  >
}

Added in v1.0.0

provideServiceEffect

Provides the effect with the single service it requires. If the effect requires more than one service use provideContext instead.

Signature

export declare const provideServiceEffect: {
  <T extends Context.Tag<any, any>, R1, E1>(tag: T, effect: Effect<R1, E1, Context.Tag.Service<T>>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R1 | Exclude<R, Context.Tag.Identifier<T>>, E1 | E, A>
  <R, E, A, T extends Context.Tag<any, any>, R1, E1>(
    self: Effect<R, E, A>,
    tag: T,
    effect: Effect<R1, E1, Context.Tag.Service<T>>
  ): Effect<R1 | Exclude<R, Context.Tag.Identifier<T>>, E | E1, A>
}

Added in v1.0.0

serviceConstants

Signature

export declare const serviceConstants: <I, S>(
  tag: Context.Tag<I, S>
) => {
  [k in { [k in keyof S]: S[k] extends Effect<any, any, any> ? k : never }[keyof S]]: S[k] extends Effect<
    infer R,
    infer E,
    infer A
  >
    ? Effect<I | R, E, A>
    : never
}

Added in v1.0.0

serviceFunction

Signature

export declare const serviceFunction: <T extends Context.Tag<any, any>, Args extends any[], A>(
  service: T,
  f: (_: Context.Tag.Service<T>) => (...args: Args) => A
) => (...args: Args) => Effect<Context.Tag.Identifier<T>, never, A>

Added in v1.0.0

serviceFunctionEffect

Signature

export declare const serviceFunctionEffect: <T extends Context.Tag<any, any>, Args extends any[], R, E, A>(
  service: T,
  f: (_: Context.Tag.Service<T>) => (...args: Args) => Effect<R, E, A>
) => (...args: Args) => Effect<R | Context.Tag.Identifier<T>, E, A>

Added in v1.0.0

serviceFunctions

Signature

export declare const serviceFunctions: <I, S>(
  tag: Context.Tag<I, S>
) => {
  [k in {
    [k in keyof S]: S[k] extends (...args: Array<any>) => Effect<any, any, any> ? k : never
  }[keyof S]]: S[k] extends (...args: infer Args) => Effect<infer R, infer E, infer A>
    ? (...args: Args) => Effect<I | R, E, A>
    : never
}

Added in v1.0.0

serviceMembers

Signature

export declare const serviceMembers: <I, S>(
  tag: Context.Tag<I, S>
) => {
  functions: {
    [k in {
      [k in keyof S]: S[k] extends (...args: Array<any>) => Effect<any, any, any> ? k : never
    }[keyof S]]: S[k] extends (...args: infer Args) => Effect<infer R, infer E, infer A>
      ? (...args: Args) => Effect<I | R, E, A>
      : never
  }
  constants: {
    [k in { [k in keyof S]: S[k] extends Effect<any, any, any> ? k : never }[keyof S]]: S[k] extends Effect<
      infer R,
      infer E,
      infer A
    >
      ? Effect<I | R, E, A>
      : never
  }
}

Added in v1.0.0

serviceOption

Signature

export declare const serviceOption: <I, A>(tag: Context.Tag<I, A>) => Effect<never, never, Option.Option<A>>

Added in v1.0.0

updateService

Updates the service with the required service entry.

Signature

export declare const updateService: {
  <T extends Context.Tag<any, any>>(tag: T, f: (service: Context.Tag.Service<T>) => Context.Tag.Service<T>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R | Context.Tag.Identifier<T>, E, A>
  <R, E, A, T extends Context.Tag<any, any>>(
    self: Effect<R, E, A>,
    tag: T,
    f: (service: Context.Tag.Service<T>) => Context.Tag.Service<T>
  ): Effect<R | Context.Tag.Identifier<T>, E, A>
}

Added in v1.0.0

conversions

either

Returns an effect whose failure and success have been lifted into an Either. The resulting effect cannot fail, because the failure case has been exposed as part of the Either success case.

This method is useful for recovering from effects that may fail.

The error parameter of the returned Effect is never, since it is guaranteed the effect does not model failure.

Signature

export declare const either: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Either.Either<E, A>>

Added in v1.0.0

exit

Signature

export declare const exit: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Exit.Exit<E, A>>

Added in v1.0.0

intoDeferred

Signature

export declare const intoDeferred: {
  <E, A>(deferred: Deferred.Deferred<E, A>): <R>(self: Effect<R, E, A>) => Effect<R, never, boolean>
  <R, E, A>(self: Effect<R, E, A>, deferred: Deferred.Deferred<E, A>): Effect<R, never, boolean>
}

Added in v1.0.0

option

Executes this effect, skipping the error but returning optionally the success.

Signature

export declare const option: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Option.Option<A>>

Added in v1.0.0

delays & timeouts

delay

Returns an effect that is delayed from this effect by the specified Duration.

Signature

export declare const delay: {
  (duration: Duration.DurationInput): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, duration: Duration.DurationInput): Effect<R, E, A>
}

Added in v1.0.0

sleep

Returns an effect that suspends for the specified duration. This method is asynchronous, and does not actually block the fiber executing the effect.

Signature

export declare const sleep: (duration: Duration.DurationInput) => Effect<never, never, void>

Added in v1.0.0

timed

Returns a new effect that executes this one and times the execution.

Signature

export declare const timed: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, readonly [Duration.Duration, A]>

Added in v1.0.0

timedWith

A more powerful variation of timed that allows specifying the clock.

Signature

export declare const timedWith: {
  <R1, E1>(nanoseconds: Effect<R1, E1, bigint>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R1 | R, E1 | E, readonly [Duration.Duration, A]>
  <R, E, A, R1, E1>(self: Effect<R, E, A>, nanoseconds: Effect<R1, E1, bigint>): Effect<
    R | R1,
    E | E1,
    readonly [Duration.Duration, A]
  >
}

Added in v1.0.0

timeout

Returns an effect that will timeout this effect, returning None if the timeout elapses before the effect has produced a value; and returning Some of the produced value otherwise.

If the timeout elapses without producing a value, the running effect will be safely interrupted.

WARNING: The effect returned by this method will not itself return until the underlying effect is actually interrupted. This leads to more predictable resource utilization. If early return is desired, then instead of using effect.timeout(d), use effect.disconnect.timeout(d), which first disconnects the effect’s interruption signal before performing the timeout, resulting in earliest possible return, before an underlying effect has been successfully interrupted.

Signature

export declare const timeout: {
  (duration: Duration.DurationInput): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, Option.Option<A>>
  <R, E, A>(self: Effect<R, E, A>, duration: Duration.DurationInput): Effect<R, E, Option.Option<A>>
}

Added in v1.0.0

timeoutFail

The same as timeout, but instead of producing a None in the event of timeout, it will produce the specified error.

Signature

export declare const timeoutFail: {
  <E1>(options: { readonly onTimeout: LazyArg<E1>; readonly duration: Duration.DurationInput }): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R, E1 | E, A>
  <R, E, A, E1>(
    self: Effect<R, E, A>,
    options: { readonly onTimeout: LazyArg<E1>; readonly duration: Duration.DurationInput }
  ): Effect<R, E | E1, A>
}

Added in v1.0.0

timeoutFailCause

The same as timeout, but instead of producing a None in the event of timeout, it will produce the specified failure.

Signature

export declare const timeoutFailCause: {
  <E1>(options: { readonly onTimeout: LazyArg<Cause.Cause<E1>>; readonly duration: Duration.DurationInput }): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R, E1 | E, A>
  <R, E, A, E1>(
    self: Effect<R, E, A>,
    options: { readonly onTimeout: LazyArg<Cause.Cause<E1>>; readonly duration: Duration.DurationInput }
  ): Effect<R, E | E1, A>
}

Added in v1.0.0

timeoutTo

Returns an effect that will timeout this effect, returning either the default value if the timeout elapses before the effect has produced a value or returning the result of applying the function onSuccess to the success value of the effect.

If the timeout elapses without producing a value, the running effect will be safely interrupted.

Signature

export declare const timeoutTo: {
  <A, B, B1>(options: {
    readonly onTimeout: LazyArg<B1>
    readonly onSuccess: (a: A) => B
    readonly duration: Duration.DurationInput
  }): <R, E>(self: Effect<R, E, A>) => Effect<R, E, B | B1>
  <R, E, A, B, B1>(
    self: Effect<R, E, A>,
    options: {
      readonly onTimeout: LazyArg<B1>
      readonly onSuccess: (a: A) => B
      readonly duration: Duration.DurationInput
    }
  ): Effect<R, E, B | B1>
}

Added in v1.0.0

do notation

Do

Signature

export declare const Do: Effect<never, never, {}>

Added in v1.0.0

bind

Binds an effectful value in a do scope

Signature

export declare const bind: {
  <N extends string, K, R2, E2, A>(tag: Exclude<N, keyof K>, f: (_: K) => Effect<R2, E2, A>): <R, E>(
    self: Effect<R, E, K>
  ) => Effect<R2 | R, E2 | E, MergeRecord<K, { [k in N]: A }>>
  <R, E, N extends string, K, R2, E2, A>(
    self: Effect<R, E, K>,
    tag: Exclude<N, keyof K>,
    f: (_: K) => Effect<R2, E2, A>
  ): Effect<R | R2, E | E2, MergeRecord<K, { [k in N]: A }>>
}

Added in v1.0.0

bindTo

Signature

export declare const bindTo: {
  <N extends string>(tag: N): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, Record<N, A>>
  <R, E, A, N extends string>(self: Effect<R, E, A>, tag: N): Effect<R, E, Record<N, A>>
}

Added in v1.0.0

let

Like bind for values

Signature

export declare const let: {
  <N extends string, K, A>(tag: Exclude<N, keyof K>, f: (_: K) => A): <R, E>(
    self: Effect<R, E, K>
  ) => Effect<R, E, MergeRecord<K, { [k in N]: A }>>
  <R, E, K, N extends string, A>(self: Effect<R, E, K>, tag: Exclude<N, keyof K>, f: (_: K) => A): Effect<
    R,
    E,
    MergeRecord<K, { [k in N]: A }>
  >
}

Added in v1.0.0

error handling

catch

Recovers from specified error.

Signature

export declare const catch: { <N extends keyof E, K extends E[N] & string, E, R1, E1, A1>(discriminator: N, options: { readonly failure: K; readonly onFailure: (error: Extract<E, { [n in N]: K; }>) => Effect<R1, E1, A1>; }): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R, E1 | Exclude<E, { [n in N]: K; }>, A1 | A>; <R, E, A, N extends keyof E, K extends E[N] & string, R1, E1, A1>(self: Effect<R, E, A>, discriminator: N, options: { readonly failure: K; readonly onFailure: (error: Extract<E, { [n in N]: K; }>) => Effect<R1, E1, A1>; }): Effect<R | R1, E1 | Exclude<E, { [n in N]: K; }>, A | A1>; }

Added in v1.0.0

catchAll

Recovers from all recoverable errors.

Note: that Effect.catchAll will not recover from unrecoverable defects. To recover from both recoverable and unrecoverable errors use Effect.catchAllCause.

Signature

export declare const catchAll: {
  <E, R2, E2, A2>(f: (e: E) => Effect<R2, E2, A2>): <R, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2, A2 | A>
  <R, A, E, R2, E2, A2>(self: Effect<R, E, A>, f: (e: E) => Effect<R2, E2, A2>): Effect<R | R2, E2, A | A2>
}

Added in v1.0.0

catchAllCause

Recovers from both recoverable and unrecoverable errors.

See absorb, sandbox, mapErrorCause for other functions that can recover from defects.

Signature

export declare const catchAllCause: {
  <E, R2, E2, A2>(f: (cause: Cause.Cause<E>) => Effect<R2, E2, A2>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2, A2 | A>
  <R, A, E, R2, E2, A2>(self: Effect<R, E, A>, f: (cause: Cause.Cause<E>) => Effect<R2, E2, A2>): Effect<
    R | R2,
    E2,
    A | A2
  >
}

Added in v1.0.0

catchAllDefect

Recovers from all defects with provided function.

WARNING: There is no sensible way to recover from defects. This method should be used only at the boundary between Effect and an external system, to transmit information on a defect for diagnostic or explanatory purposes.

Signature

export declare const catchAllDefect: {
  <R2, E2, A2>(f: (defect: unknown) => Effect<R2, E2, A2>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, A2 | A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, f: (defect: unknown) => Effect<R2, E2, A2>): Effect<
    R | R2,
    E | E2,
    A | A2
  >
}

Added in v1.0.0

catchIf

Recovers from errors that match the given predicate.

Signature

export declare const catchIf: {
  <E, EA extends E, EB extends EA, R2, E2, A2>(refinement: Refinement<EA, EB>, f: (e: EB) => Effect<R2, E2, A2>): <
    R,
    A
  >(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | Exclude<E, EB>, A2 | A>
  <E, EX extends E, R2, E2, A2>(predicate: Predicate<EX>, f: (e: EX) => Effect<R2, E2, A2>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E | E2, A2 | A>
  <R, E, A, EA extends E, EB extends EA, R2, E2, A2>(
    self: Effect<R, E, A>,
    refinement: Refinement<EA, EB>,
    f: (e: EB) => Effect<R2, E2, A2>
  ): Effect<R | R2, E2 | Exclude<E, EB>, A | A2>
  <R, E, A, EX extends E, R2, E2, A2>(
    self: Effect<R, E, A>,
    predicate: Predicate<EX>,
    f: (e: EX) => Effect<R2, E2, A2>
  ): Effect<R | R2, E | E2, A | A2>
}

Added in v1.0.0

catchSome

Recovers from some or all of the error cases.

Signature

export declare const catchSome: {
  <E, R2, E2, A2>(pf: (e: E) => Option.Option<Effect<R2, E2, A2>>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E | E2, A2 | A>
  <R, A, E, R2, E2, A2>(self: Effect<R, E, A>, pf: (e: E) => Option.Option<Effect<R2, E2, A2>>): Effect<
    R | R2,
    E | E2,
    A | A2
  >
}

Added in v1.0.0

catchSomeCause

Recovers from some or all of the error cases with provided cause.

Signature

export declare const catchSomeCause: {
  <E, R2, E2, A2>(f: (cause: Cause.Cause<E>) => Option.Option<Effect<R2, E2, A2>>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E | E2, A2 | A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, f: (cause: Cause.Cause<E>) => Option.Option<Effect<R2, E2, A2>>): Effect<
    R | R2,
    E | E2,
    A | A2
  >
}

Added in v1.0.0

catchSomeDefect

Recovers from some or all of the defects with provided partial function.

WARNING: There is no sensible way to recover from defects. This method should be used only at the boundary between Effect and an external system, to transmit information on a defect for diagnostic or explanatory purposes.

Signature

export declare const catchSomeDefect: {
  <R2, E2, A2>(pf: (defect: unknown) => Option.Option<Effect<R2, E2, A2>>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, A2 | A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, pf: (defect: unknown) => Option.Option<Effect<R2, E2, A2>>): Effect<
    R | R2,
    E | E2,
    A | A2
  >
}

Added in v1.0.0

catchTag

Recovers from the specified tagged error.

Signature

export declare const catchTag: {
  <K extends E extends { _tag: string } ? E['_tag'] : never, E, R1, E1, A1>(
    k: K,
    f: (e: Extract<E, { _tag: K }>) => Effect<R1, E1, A1>
  ): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R, E1 | Exclude<E, { _tag: K }>, A1 | A>
  <R, E, A, K extends E extends { _tag: string } ? E['_tag'] : never, R1, E1, A1>(
    self: Effect<R, E, A>,
    k: K,
    f: (e: Extract<E, { _tag: K }>) => Effect<R1, E1, A1>
  ): Effect<R | R1, E1 | Exclude<E, { _tag: K }>, A | A1>
}

Added in v1.0.0

catchTags

Recovers from the specified tagged errors.

Signature

export declare const catchTags: {
  <
    E,
    Cases extends E extends { _tag: string }
      ? { [K in E['_tag']]+?: ((error: Extract<E, { _tag: K }>) => Effect<any, any, any>) | undefined }
      : {}
  >(
    cases: Cases
  ): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<
    | R
    | {
        [K in keyof Cases]: Cases[K] extends (...args: Array<any>) => Effect<infer R, any, any> ? R : never
      }[keyof Cases],
    | Exclude<E, { _tag: keyof Cases }>
    | {
        [K in keyof Cases]: Cases[K] extends (...args: Array<any>) => Effect<any, infer E, any> ? E : never
      }[keyof Cases],
    | A
    | {
        [K in keyof Cases]: Cases[K] extends (...args: Array<any>) => Effect<any, any, infer A> ? A : never
      }[keyof Cases]
  >
  <
    R,
    E,
    A,
    Cases extends E extends { _tag: string }
      ? { [K in E['_tag']]+?: ((error: Extract<E, { _tag: K }>) => Effect<any, any, any>) | undefined }
      : {}
  >(
    self: Effect<R, E, A>,
    cases: Cases
  ): Effect<
    | R
    | {
        [K in keyof Cases]: Cases[K] extends (...args: Array<any>) => Effect<infer R, any, any> ? R : never
      }[keyof Cases],
    | Exclude<E, { _tag: keyof Cases }>
    | {
        [K in keyof Cases]: Cases[K] extends (...args: Array<any>) => Effect<any, infer E, any> ? E : never
      }[keyof Cases],
    | A
    | {
        [K in keyof Cases]: Cases[K] extends (...args: Array<any>) => Effect<any, any, infer A> ? A : never
      }[keyof Cases]
  >
}

Added in v1.0.0

cause

Returns an effect that succeeds with the cause of failure of this effect, or Cause.empty if the effect did succeed.

Signature

export declare const cause: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Cause.Cause<E>>

Added in v1.0.0

eventually

Returns an effect that ignores errors and runs repeatedly until it eventually succeeds.

Signature

export declare const eventually: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, A>

Added in v1.0.0

ignore

Returns a new effect that ignores the success or failure of this effect.

Signature

export declare const ignore: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, void>

Added in v1.0.0

ignoreLogged

Returns a new effect that ignores the success or failure of this effect, but which also logs failures at the Debug level, just in case the failure turns out to be important.

Signature

export declare const ignoreLogged: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, void>

Added in v1.0.0

parallelErrors

Exposes all parallel errors in a single call.

Signature

export declare const parallelErrors: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E[], A>

Added in v1.0.0

retry

Retries with the specified retry policy. Retries are done following the failure of the original io (up to a fixed maximum with once or recurs for example), so that that io.retry(Schedule.once) means “execute io and in case of failure, try again once”.

Signature

export declare const retry: {
  <R1, E extends E0, E0, B>(policy: Schedule.Schedule<R1, E0, B>): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R, E, A>
  <R, E extends E0, E0, A, R1, B>(self: Effect<R, E, A>, policy: Schedule.Schedule<R1, E0, B>): Effect<R | R1, E, A>
}

Added in v1.0.0

retryN

Retries this effect the specified number of times.

Signature

export declare const retryN: {
  (n: number): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, n: number): Effect<R, E, A>
}

Added in v1.0.0

retryOrElse

Retries with the specified schedule, until it fails, and then both the value produced by the schedule together with the last error are passed to the recovery function.

Signature

export declare const retryOrElse: {
  <R1, E extends E3, A1, R2, E2, A2, E3>(
    policy: Schedule.Schedule<R1, E3, A1>,
    orElse: (e: E, out: A1) => Effect<R2, E2, A2>
  ): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R2 | R, E | E2, A2 | A>
  <R, E extends E3, A, R1, A1, R2, E2, A2, E3>(
    self: Effect<R, E, A>,
    policy: Schedule.Schedule<R1, E3, A1>,
    orElse: (e: E, out: A1) => Effect<R2, E2, A2>
  ): Effect<R | R1 | R2, E | E2, A | A2>
}

Added in v1.0.0

retryUntil

Retries this effect until its error satisfies the specified predicate.

Signature

export declare const retryUntil: {
  <E, E2 extends E>(f: Refinement<E, E2>): <R, A>(self: Effect<R, E, A>) => Effect<R, E2, A>
  <E>(f: Predicate<E>): <R, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A, E2 extends E>(self: Effect<R, E, A>, f: Refinement<E, E2>): Effect<R, E2, A>
  <R, E, A>(self: Effect<R, E, A>, f: Predicate<E>): Effect<R, E, A>
}

Added in v1.0.0

retryUntilEffect

Retries this effect until its error satisfies the specified effectful predicate.

Signature

export declare const retryUntilEffect: {
  <R1, E, E2>(f: (e: E) => Effect<R1, E2, boolean>): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R, E | E2, A>
  <R, E, A, R1, E2>(self: Effect<R, E, A>, f: (e: E) => Effect<R1, E2, boolean>): Effect<R | R1, E | E2, A>
}

Added in v1.0.0

retryWhile

Retries this effect while its error satisfies the specified predicate.

Signature

export declare const retryWhile: {
  <E>(f: Predicate<E>): <R, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, f: Predicate<E>): Effect<R, E, A>
}

Added in v1.0.0

retryWhileEffect

Retries this effect while its error satisfies the specified effectful predicate.

Signature

export declare const retryWhileEffect: {
  <R1, E, E2>(f: (e: E) => Effect<R1, E2, boolean>): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R, E | E2, A>
  <R, E, A, R1, E2>(self: Effect<R, E, A>, f: (e: E) => Effect<R1, E2, boolean>): Effect<R | R1, E | E2, A>
}

Added in v1.0.0

sandbox

Exposes the full Cause of failure for the specified effect.

Signature

export declare const sandbox: <R, E, A>(self: Effect<R, E, A>) => Effect<R, Cause.Cause<E>, A>

Added in v1.0.0

try

Imports a synchronous side-effect into a pure Effect value, translating any thrown exceptions into typed failed effects creating with Effect.fail.

Signature

export declare const try: { <A, E>(options: { readonly try: LazyArg<A>; readonly catch: (error: unknown) => E; }): Effect<never, E, A>; <A>(evaluate: LazyArg<A>): Effect<never, unknown, A>; }

Added in v1.0.0

tryMap

Returns an effect whose success is mapped by the specified side effecting try function, translating any promise rejections into typed failed effects via the catch function.

Signature

export declare const tryMap: {
  <A, B, E1>(options: { readonly try: (a: A) => B; readonly catch: (error: unknown) => E1 }): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R, E1 | E, B>
  <R, E, A, B, E1>(
    self: Effect<R, E, A>,
    options: { readonly try: (a: A) => B; readonly catch: (error: unknown) => E1 }
  ): Effect<R, E | E1, B>
}

Added in v1.0.0

tryMapPromise

Returns an effect whose success is mapped by the specified side effecting try function, translating any promise rejections into typed failed effects via the catch function.

An optional AbortSignal can be provided to allow for interruption of the wrapped Promise api.

Signature

export declare const tryMapPromise: {
  <A, B, E1>(options: {
    readonly try: (a: A, signal: AbortSignal) => Promise<B>
    readonly catch: (error: unknown) => E1
  }): <R, E>(self: Effect<R, E, A>) => Effect<R, E1 | E, B>
  <R, E, A, B, E1>(
    self: Effect<R, E, A>,
    options: { readonly try: (a: A, signal: AbortSignal) => Promise<B>; readonly catch: (error: unknown) => E1 }
  ): Effect<R, E | E1, B>
}

Added in v1.0.0

tryPromise

Create an Effect that when executed will construct promise and wait for its result, errors will produce failure as unknown.

An optional AbortSignal can be provided to allow for interruption of the wrapped Promise api.

Signature

export declare const tryPromise: {
  <A, E>(options: { readonly try: (signal: AbortSignal) => Promise<A>; readonly catch: (error: unknown) => E }): Effect<
    never,
    E,
    A
  >
  <A>(try_: (signal: AbortSignal) => Promise<A>): Effect<never, unknown, A>
}

Added in v1.0.0

unsandbox

The inverse operation sandbox(effect)

Terminates with exceptions on the Left side of the Either error, if it exists. Otherwise extracts the contained Effect<R, E, A>

Signature

export declare const unsandbox: <R, E, A>(self: Effect<R, Cause.Cause<E>, A>) => Effect<R, E, A>

Added in v1.0.0

execution

runCallback

Signature

export declare const runCallback: <E, A>(
  effect: Effect<never, E, A>,
  onExit?: ((exit: Exit.Exit<E, A>) => void) | undefined
) => Runtime.Cancel<E, A>

Added in v1.0.0

runFork

Signature

export declare const runFork: <E, A>(effect: Effect<never, E, A>) => Fiber.RuntimeFiber<E, A>

Added in v1.0.0

runPromise

Runs an Effect workflow, returning a Promise which resolves with the result of the workflow or rejects with an error.

Signature

export declare const runPromise: <E, A>(effect: Effect<never, E, A>) => Promise<A>

Added in v1.0.0

runPromiseExit

Runs an Effect workflow, returning a Promise which resolves with the Exit value of the workflow.

Signature

export declare const runPromiseExit: <E, A>(effect: Effect<never, E, A>) => Promise<Exit.Exit<E, A>>

Added in v1.0.0

runSync

Signature

export declare const runSync: <E, A>(effect: Effect<never, E, A>) => A

Added in v1.0.0

runSyncExit

Signature

export declare const runSyncExit: <E, A>(effect: Effect<never, E, A>) => Exit.Exit<E, A>

Added in v1.0.0

fiber refs

getFiberRefs

Returns a collection of all FiberRef values for the fiber running this effect.

Signature

export declare const getFiberRefs: Effect<never, never, FiberRefs.FiberRefs>

Added in v1.0.0

inheritFiberRefs

Inherits values from all FiberRef instances into current fiber.

Signature

export declare const inheritFiberRefs: (childFiberRefs: FiberRefs.FiberRefs) => Effect<never, never, void>

Added in v1.0.0

locally

Signature

export declare const locally: {
  <A>(self: FiberRef.FiberRef<A>, value: A): <R, E, B>(use: Effect<R, E, B>) => Effect<R, E, B>
  <R, E, B, A>(use: Effect<R, E, B>, self: FiberRef.FiberRef<A>, value: A): Effect<R, E, B>
}

Added in v1.0.0

locallyScoped

Signature

export declare const locallyScoped: {
  <A>(value: A): (self: FiberRef.FiberRef<A>) => Effect<Scope.Scope, never, void>
  <A>(self: FiberRef.FiberRef<A>, value: A): Effect<Scope.Scope, never, void>
}

Added in v1.0.0

locallyScopedWith

Signature

export declare const locallyScopedWith: {
  <A>(f: (a: A) => A): (self: FiberRef.FiberRef<A>) => Effect<Scope.Scope, never, void>
  <A>(self: FiberRef.FiberRef<A>, f: (a: A) => A): Effect<Scope.Scope, never, void>
}

Added in v1.0.0

locallyWith

Signature

export declare const locallyWith: {
  <A>(self: FiberRef.FiberRef<A>, f: (a: A) => A): <R, E, B>(use: Effect<R, E, B>) => Effect<R, E, B>
  <R, E, B, A>(use: Effect<R, E, B>, self: FiberRef.FiberRef<A>, f: (a: A) => A): Effect<R, E, B>
}

Added in v1.0.0

patchFiberRefs

Applies the specified changes to the FiberRef values for the fiber running this workflow.

Signature

export declare const patchFiberRefs: (patch: FiberRefsPatch.FiberRefsPatch) => Effect<never, never, void>

Added in v1.0.0

setFiberRefs

Sets the FiberRef values for the fiber running this effect to the values in the specified collection of FiberRef values.

Signature

export declare const setFiberRefs: (fiberRefs: FiberRefs.FiberRefs) => Effect<never, never, void>

Added in v1.0.0

updateFiberRefs

Updates the FiberRef values for the fiber running this effect using the specified function.

Signature

export declare const updateFiberRefs: (
  f: (fiberId: FiberId.Runtime, fiberRefs: FiberRefs.FiberRefs) => FiberRefs.FiberRefs
) => Effect<never, never, void>

Added in v1.0.0

filtering & conditionals

filterOrDie

Filter the specified effect with the provided function, dying with specified defect if the predicate fails.

Signature

export declare const filterOrDie: {
  <A, B extends A, X extends A>(filter: Refinement<A, B>, orDieWith: (a: X) => unknown): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R, E, B>
  <A, X extends A, Y extends A>(filter: Predicate<X>, orDieWith: (a: Y) => unknown): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R, E, A>
  <R, E, A, B extends A, X extends A>(
    self: Effect<R, E, A>,
    filter: Refinement<A, B>,
    orDieWith: (a: X) => unknown
  ): Effect<R, E, B>
  <R, E, A, X extends A, Y extends A>(
    self: Effect<R, E, A>,
    filter: Predicate<X>,
    orDieWith: (a: Y) => unknown
  ): Effect<R, E, A>
}

Added in v1.0.0

filterOrDieMessage

Filter the specified effect with the provided function, dying with specified message if the predicate fails.

Signature

export declare const filterOrDieMessage: {
  <A, B extends A>(filter: Refinement<A, B>, message: string): <R, E>(self: Effect<R, E, A>) => Effect<R, E, B>
  <A, X extends A>(filter: Predicate<X>, message: string): <R, E>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A, B extends A>(self: Effect<R, E, A>, filter: Refinement<A, B>, message: string): Effect<R, E, B>
  <R, E, A, X extends A>(self: Effect<R, E, A>, filter: Predicate<X>, message: string): Effect<R, E, A>
}

Added in v1.0.0

filterOrElse

Filters the specified effect with the provided function returning the value of the effect if it is successful, otherwise returns the value of orElse.

Signature

export declare const filterOrElse: {
  <A, B extends A, X extends A, R2, E2, C>(filter: Refinement<A, B>, orElse: (a: X) => Effect<R2, E2, C>): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, B | C>
  <A, X extends A, Y extends A, R2, E2, B>(filter: Predicate<X>, orElse: (a: Y) => Effect<R2, E2, B>): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, A | B>
  <R, E, A, B extends A, X extends A, R2, E2, C>(
    self: Effect<R, E, A>,
    filter: Refinement<A, B>,
    orElse: (a: X) => Effect<R2, E2, C>
  ): Effect<R | R2, E | E2, B | C>
  <R, E, A, X extends A, Y extends A, R2, E2, B>(
    self: Effect<R, E, A>,
    filter: Predicate<X>,
    orElse: (a: Y) => Effect<R2, E2, B>
  ): Effect<R | R2, E | E2, A | B>
}

Added in v1.0.0

filterOrFail

Filter the specified effect with the provided function, failing with specified error if the predicate fails.

Signature

export declare const filterOrFail: {
  <A, B extends A, X extends A, E2>(filter: Refinement<A, B>, orFailWith: (a: X) => E2): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R, E2 | E, B>
  <A, X extends A, Y extends A, E2>(filter: Predicate<X>, orFailWith: (a: Y) => E2): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R, E2 | E, A>
  <R, E, A, B extends A, X extends A, E2>(
    self: Effect<R, E, A>,
    filter: Refinement<A, B>,
    orFailWith: (a: X) => E2
  ): Effect<R, E | E2, B>
  <R, E, A, X extends A, Y extends A, E2>(
    self: Effect<R, E, A>,
    filter: Predicate<X>,
    orFailWith: (a: Y) => E2
  ): Effect<R, E | E2, A>
}

Added in v1.0.0

if

Runs onTrue if the result of self is true and onFalse otherwise.

Signature

export declare const if: { <R1, R2, E1, E2, A, A1>(options: { readonly onTrue: Effect<R1, E1, A>; readonly onFalse: Effect<R2, E2, A1>; }): <R = never, E = never>(self: boolean | Effect<R, E, boolean>) => Effect<R1 | R2 | R, E1 | E2 | E, A | A1>; <R1, R2, E1, E2, A, A1>(self: boolean, options: { readonly onTrue: Effect<R1, E1, A>; readonly onFalse: Effect<R2, E2, A1>; }): Effect<R1 | R2, E1 | E2, A | A1>; <R, E, R1, R2, E1, E2, A, A1>(self: Effect<R, E, boolean>, options: { readonly onTrue: Effect<R1, E1, A>; readonly onFalse: Effect<R2, E2, A1>; }): Effect<R | R1 | R2, E | E1 | E2, A | A1>; }

Added in v1.0.0

unless

The moral equivalent of if (!p) exp.

Signature

export declare const unless: {
  (predicate: LazyArg<boolean>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, Option.Option<A>>
  <R, E, A>(self: Effect<R, E, A>, predicate: LazyArg<boolean>): Effect<R, E, Option.Option<A>>
}

Added in v1.0.0

unlessEffect

The moral equivalent of if (!p) exp when p has side-effects.

Signature

export declare const unlessEffect: {
  <R2, E2>(predicate: Effect<R2, E2, boolean>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, Option.Option<A>>
  <R, E, A, R2, E2>(self: Effect<R, E, A>, predicate: Effect<R2, E2, boolean>): Effect<R | R2, E | E2, Option.Option<A>>
}

Added in v1.0.0

when

The moral equivalent of if (p) exp.

Signature

export declare const when: {
  (predicate: LazyArg<boolean>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, Option.Option<A>>
  <R, E, A>(self: Effect<R, E, A>, predicate: LazyArg<boolean>): Effect<R, E, Option.Option<A>>
}

Added in v1.0.0

whenEffect

Signature

export declare const whenEffect: {
  <R, E>(predicate: Effect<R, E, boolean>): <R2, E2, A>(
    effect: Effect<R2, E2, A>
  ) => Effect<R | R2, E | E2, Option.Option<A>>
  <R, E, A, R2, E2>(self: Effect<R2, E2, A>, predicate: Effect<R, E, boolean>): Effect<R | R2, E | E2, Option.Option<A>>
}

Added in v1.0.0

whenFiberRef

Executes this workflow when value of the specified FiberRef satisfies the predicate.

Signature

export declare const whenFiberRef: {
  <S>(fiberRef: FiberRef.FiberRef<S>, predicate: Predicate<S>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R, E, readonly [S, Option.Option<A>]>
  <R, E, A, S>(self: Effect<R, E, A>, fiberRef: FiberRef.FiberRef<S>, predicate: Predicate<S>): Effect<
    R,
    E,
    readonly [S, Option.Option<A>]
  >
}

Added in v1.0.0

whenRef

Executes this workflow when the value of the Ref satisfies the predicate.

Signature

export declare const whenRef: {
  <S>(ref: Ref.Ref<S>, predicate: Predicate<S>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R, E, readonly [S, Option.Option<A>]>
  <R, E, A, S>(self: Effect<R, E, A>, ref: Ref.Ref<S>, predicate: Predicate<S>): Effect<
    R,
    E,
    readonly [S, Option.Option<A>]
  >
}

Added in v1.0.0

getters & folding

isFailure

Returns true if this effect is a failure, false otherwise.

Signature

export declare const isFailure: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, boolean>

Added in v1.0.0

isSuccess

Returns true if this effect is a success, false otherwise.

Signature

export declare const isSuccess: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, boolean>

Added in v1.0.0

match

Folds over the failure value or the success value to yield an effect that does not fail, but succeeds with the value returned by the left or right function passed to match.

Signature

export declare const match: {
  <E, A, A2, A3>(options: { readonly onFailure: (error: E) => A2; readonly onSuccess: (value: A) => A3 }): <R>(
    self: Effect<R, E, A>
  ) => Effect<R, never, A2 | A3>
  <R, E, A, A2, A3>(
    self: Effect<R, E, A>,
    options: { readonly onFailure: (error: E) => A2; readonly onSuccess: (value: A) => A3 }
  ): Effect<R, never, A2 | A3>
}

Added in v1.0.0

matchCause

Signature

export declare const matchCause: {
  <E, A2, A, A3>(options: { readonly onFailure: (cause: Cause.Cause<E>) => A2; readonly onSuccess: (a: A) => A3 }): <R>(
    self: Effect<R, E, A>
  ) => Effect<R, never, A2 | A3>
  <R, E, A2, A, A3>(
    self: Effect<R, E, A>,
    options: { readonly onFailure: (cause: Cause.Cause<E>) => A2; readonly onSuccess: (a: A) => A3 }
  ): Effect<R, never, A2 | A3>
}

Added in v1.0.0

matchCauseEffect

Signature

export declare const matchCauseEffect: {
  <E, A, R2, E2, A2, R3, E3, A3>(options: {
    readonly onFailure: (cause: Cause.Cause<E>) => Effect<R2, E2, A2>
    readonly onSuccess: (a: A) => Effect<R3, E3, A3>
  }): <R>(self: Effect<R, E, A>) => Effect<R2 | R3 | R, E2 | E3, A2 | A3>
  <R, E, A, R2, E2, A2, R3, E3, A3>(
    self: Effect<R, E, A>,
    options: {
      readonly onFailure: (cause: Cause.Cause<E>) => Effect<R2, E2, A2>
      readonly onSuccess: (a: A) => Effect<R3, E3, A3>
    }
  ): Effect<R | R2 | R3, E2 | E3, A2 | A3>
}

Added in v1.0.0

matchEffect

Signature

export declare const matchEffect: {
  <E, A, R2, E2, A2, R3, E3, A3>(options: {
    readonly onFailure: (e: E) => Effect<R2, E2, A2>
    readonly onSuccess: (a: A) => Effect<R3, E3, A3>
  }): <R>(self: Effect<R, E, A>) => Effect<R2 | R3 | R, E2 | E3, A2 | A3>
  <R, E, A, R2, E2, A2, R3, E3, A3>(
    self: Effect<R, E, A>,
    options: { readonly onFailure: (e: E) => Effect<R2, E2, A2>; readonly onSuccess: (a: A) => Effect<R3, E3, A3> }
  ): Effect<R | R2 | R3, E2 | E3, A2 | A3>
}

Added in v1.0.0

interruption

allowInterrupt

This function checks if any fibers are attempting to interrupt the current fiber, and if so, performs self-interruption.

Note that this allows for interruption to occur in uninterruptible regions.

Signature

export declare const allowInterrupt: Effect<never, never, void>

Added in v1.0.0

checkInterruptible

Checks the interrupt status, and produces the effect returned by the specified callback.

Signature

export declare const checkInterruptible: <R, E, A>(f: (isInterruptible: boolean) => Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

disconnect

Returns an effect whose interruption will be disconnected from the fiber’s own interruption, being performed in the background without slowing down the fiber’s interruption.

This method is useful to create “fast interrupting” effects. For example, if you call this on a bracketed effect, then even if the effect is “stuck” in acquire or release, its interruption will return immediately, while the acquire / release are performed in the background.

See timeout and race for other applications.

Signature

export declare const disconnect: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

interrupt

Signature

export declare const interrupt: Effect<never, never, never>

Added in v1.0.0

interruptWith

Signature

export declare const interruptWith: (fiberId: FiberId.FiberId) => Effect<never, never, never>

Added in v1.0.0

interruptible

Signature

export declare const interruptible: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

interruptibleMask

Signature

export declare const interruptibleMask: <R, E, A>(
  f: (restore: <RX, EX, AX>(effect: Effect<RX, EX, AX>) => Effect<RX, EX, AX>) => Effect<R, E, A>
) => Effect<R, E, A>

Added in v1.0.0

onInterrupt

Signature

export declare const onInterrupt: {
  <R2, X>(cleanup: (interruptors: HashSet.HashSet<FiberId.FiberId>) => Effect<R2, never, X>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E, A>
  <R, E, A, R2, X>(
    self: Effect<R, E, A>,
    cleanup: (interruptors: HashSet.HashSet<FiberId.FiberId>) => Effect<R2, never, X>
  ): Effect<R | R2, E, A>
}

Added in v1.0.0

uninterruptible

Signature

export declare const uninterruptible: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

uninterruptibleMask

Signature

export declare const uninterruptibleMask: <R, E, A>(
  f: (restore: <RX, EX, AX>(effect: Effect<RX, EX, AX>) => Effect<RX, EX, AX>) => Effect<R, E, A>
) => Effect<R, E, A>

Added in v1.0.0

logging

annotateLogs

Annotates each log in this effect with the specified log annotation.

Signature

export declare const annotateLogs: {
  (key: string, value: Logger.AnnotationValue): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  (values: Record<string, Logger.AnnotationValue>): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, key: string, value: Logger.AnnotationValue): Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, values: Record<string, Logger.AnnotationValue>): Effect<R, E, A>
}

Added in v1.0.0

log

Logs the specified message or cause at the current log level.

You can set the current log level using FiberRef.currentLogLevel.

Signature

export declare const log: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

logAnnotations

Retrieves the log annotations associated with the current scope.

Signature

export declare const logAnnotations: Effect<never, never, HashMap.HashMap<string, Logger.AnnotationValue>>

Added in v1.0.0

logDebug

Logs the specified message or cause at the Debug log level.

Signature

export declare const logDebug: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

logError

Logs the specified message or cause at the Error log level.

Signature

export declare const logError: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

logFatal

Logs the specified message or cause at the Fatal log level.

Signature

export declare const logFatal: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

logInfo

Logs the specified message or cause at the Info log level.

Signature

export declare const logInfo: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

logTrace

Logs the specified message or cause at the Trace log level.

Signature

export declare const logTrace: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

logWarning

Logs the specified message or cause at the Warning log level.

Signature

export declare const logWarning: <A>(
  messageOrCause: A,
  supplementary?: (A extends Cause.Cause<any> ? unknown : Cause.Cause<unknown>) | undefined
) => Effect<never, never, void>

Added in v1.0.0

setUnhandledErrorLogLevel

Signature

export declare const setUnhandledErrorLogLevel: (level: Option.Option<LogLevel>) => Layer.Layer<never, never, never>

Added in v1.0.0

withLogSpan

Adjusts the label for the current logging span.

Signature

export declare const withLogSpan: {
  (label: string): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, label: string): Effect<R, E, A>
}

Added in v1.0.0

withUnhandledErrorLogLevel

Decides wether child fibers will report or not unhandled errors via the logger

Signature

export declare const withUnhandledErrorLogLevel: {
  (level: Option.Option<LogLevel>): <R, E, B>(self: Effect<R, E, B>) => Effect<R, E, B>
  <R, E, B>(self: Effect<R, E, B>, level: Option.Option<LogLevel>): Effect<R, E, B>
}

Added in v1.0.0

mapping

as

This function maps the success value of an Effect value to a specified constant value.

Signature

export declare const as: {
  <B>(value: B): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, B>
  <R, E, A, B>(self: Effect<R, E, A>, value: B): Effect<R, E, B>
}

Added in v1.0.0

asSome

This function maps the success value of an Effect value to a Some value in an Option value. If the original Effect value fails, the returned Effect value will also fail.

Signature

export declare const asSome: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, Option.Option<A>>

Added in v1.0.0

asSomeError

This function maps the error value of an Effect value to a Some value in an Option value. If the original Effect value succeeds, the returned Effect value will also succeed.

Signature

export declare const asSomeError: <R, E, A>(self: Effect<R, E, A>) => Effect<R, Option.Option<E>, A>

Added in v1.0.0

asUnit

This function maps the success value of an Effect value to void. If the original Effect value succeeds, the returned Effect value will also succeed. If the original Effect value fails, the returned Effect value will fail with the same error.

Signature

export declare const asUnit: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, void>

Added in v1.0.0

flip

Returns an effect that swaps the error/success cases. This allows you to use all methods on the error channel, possibly before flipping back.

Signature

export declare const flip: <R, E, A>(self: Effect<R, E, A>) => Effect<R, A, E>

Added in v1.0.0

flipWith

Swaps the error/value parameters, applies the function f and flips the parameters back

Signature

export declare const flipWith: {
  <R, A, E, R2, A2, E2>(f: (effect: Effect<R, A, E>) => Effect<R2, A2, E2>): (
    self: Effect<R, E, A>
  ) => Effect<R2, E2, A2>
  <R, A, E, R2, A2, E2>(self: Effect<R, E, A>, f: (effect: Effect<R, A, E>) => Effect<R2, A2, E2>): Effect<R2, E2, A2>
}

Added in v1.0.0

map

Signature

export declare const map: {
  <A, B>(f: (a: A) => B): <R, E>(self: Effect<R, E, A>) => Effect<R, E, B>
  <R, E, A, B>(self: Effect<R, E, A>, f: (a: A) => B): Effect<R, E, B>
}

Added in v1.0.0

mapAccum

Statefully and effectfully maps over the elements of this chunk to produce new elements.

Signature

export declare const mapAccum: {
  <A, B, R, E, Z>(zero: Z, f: (z: Z, a: A, i: number) => Effect<R, E, readonly [Z, B]>): (
    elements: Iterable<A>
  ) => Effect<R, E, readonly [Z, B[]]>
  <A, B, R, E, Z>(elements: Iterable<A>, zero: Z, f: (z: Z, a: A, i: number) => Effect<R, E, readonly [Z, B]>): Effect<
    R,
    E,
    readonly [Z, B[]]
  >
}

Added in v1.0.0

mapBoth

Returns an effect whose failure and success channels have been mapped by the specified onFailure and onSuccess functions.

Signature

export declare const mapBoth: {
  <E, A, E2, A2>(options: { readonly onFailure: (e: E) => E2; readonly onSuccess: (a: A) => A2 }): <R>(
    self: Effect<R, E, A>
  ) => Effect<R, E2, A2>
  <R, E, A, E2, A2>(
    self: Effect<R, E, A>,
    options: { readonly onFailure: (e: E) => E2; readonly onSuccess: (a: A) => A2 }
  ): Effect<R, E2, A2>
}

Added in v1.0.0

mapError

Returns an effect with its error channel mapped using the specified function.

Signature

export declare const mapError: {
  <E, E2>(f: (e: E) => E2): <R, A>(self: Effect<R, E, A>) => Effect<R, E2, A>
  <R, A, E, E2>(self: Effect<R, E, A>, f: (e: E) => E2): Effect<R, E2, A>
}

Added in v1.0.0

mapErrorCause

Returns an effect with its full cause of failure mapped using the specified function. This can be used to transform errors while preserving the original structure of Cause.

See absorb, sandbox, catchAllCause for other functions for dealing with defects.

Signature

export declare const mapErrorCause: {
  <E, E2>(f: (cause: Cause.Cause<E>) => Cause.Cause<E2>): <R, A>(self: Effect<R, E, A>) => Effect<R, E2, A>
  <R, E, A, E2>(self: Effect<R, E, A>, f: (cause: Cause.Cause<E>) => Cause.Cause<E2>): Effect<R, E2, A>
}

Added in v1.0.0

merge

Returns a new effect where the error channel has been merged into the success channel to their common combined type.

Signature

export declare const merge: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, E | A>

Added in v1.0.0

negate

Returns a new effect where boolean value of this effect is negated.

Signature

export declare const negate: <R, E>(self: Effect<R, E, boolean>) => Effect<R, E, boolean>

Added in v1.0.0

metrics

labelMetrics

Tags each metric in this effect with the specific tag.

Signature

export declare const labelMetrics: {
  (labels: Iterable<MetricLabel.MetricLabel>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, labels: Iterable<MetricLabel.MetricLabel>): Effect<R, E, A>
}

Added in v1.0.0

labelMetricsScoped

Tags each metric in a scope with a the specific tag.

Signature

export declare const labelMetricsScoped: (
  labels: ReadonlyArray<MetricLabel.MetricLabel>
) => Effect<Scope.Scope, never, void>

Added in v1.0.0

labelMetricsScopedSet

Tags each metric in a scope with a the specific tag.

Signature

export declare const labelMetricsScopedSet: (
  labels: HashSet.HashSet<MetricLabel.MetricLabel>
) => Effect<Scope.Scope, never, void>

Added in v1.0.0

labelMetricsSet

Tags each metric in this effect with the specific tag.

Signature

export declare const labelMetricsSet: {
  (labels: HashSet.HashSet<MetricLabel.MetricLabel>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, labels: HashSet.HashSet<MetricLabel.MetricLabel>): Effect<R, E, A>
}

Added in v1.0.0

metricLabels

Retrieves the metric labels associated with the current scope.

Signature

export declare const metricLabels: Effect<never, never, HashSet.HashSet<MetricLabel.MetricLabel>>

Added in v1.0.0

tagMetrics

Tags each metric in this effect with the specific tag.

Signature

export declare const tagMetrics: {
  (key: string, value: string): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, key: string, value: string): Effect<R, E, A>
}

Added in v1.0.0

tagMetricsScoped

Tags each metric in a scope with a the specific tag.

Signature

export declare const tagMetricsScoped: (key: string, value: string) => Effect<Scope.Scope, never, void>

Added in v1.0.0

withMetric

Signature

export declare const withMetric: {
  <Type, In, Out>(metric: Metric.Metric<Type, In, Out>): <R, E, A extends In>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A extends In, Type, In, Out>(self: Effect<R, E, A>, metric: Metric.Metric<Type, In, Out>): Effect<R, E, A>
}

Added in v1.0.0

models

Adapter (interface)

Signature

export interface Adapter {
  <R, E, A>(self: Effect<R, E, A>): EffectGen<R, E, A>
  <A, _R, _E, _A>(a: A, ab: (a: A) => Effect<_R, _E, _A>): EffectGen<_R, _E, _A>
  <A, B, _R, _E, _A>(a: A, ab: (a: A) => B, bc: (b: B) => Effect<_R, _E, _A>): EffectGen<_R, _E, _A>
  <A, B, C, _R, _E, _A>(a: A, ab: (a: A) => B, bc: (b: B) => C, cd: (c: C) => Effect<_R, _E, _A>): EffectGen<_R, _E, _A>
  <A, B, C, D, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (g: H) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => O,
    op: (o: O) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => O,
    op: (o: O) => P,
    pq: (p: P) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => O,
    op: (o: O) => P,
    pq: (p: P) => Q,
    qr: (q: Q) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => O,
    op: (o: O) => P,
    pq: (p: P) => Q,
    qr: (q: Q) => R,
    rs: (r: R) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => O,
    op: (o: O) => P,
    pq: (p: P) => Q,
    qr: (q: Q) => R,
    rs: (r: R) => S,
    st: (s: S) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
  <A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, _R, _E, _A>(
    a: A,
    ab: (a: A) => B,
    bc: (b: B) => C,
    cd: (c: C) => D,
    de: (d: D) => E,
    ef: (e: E) => F,
    fg: (f: F) => G,
    gh: (g: G) => H,
    hi: (h: H) => I,
    ij: (i: I) => J,
    jk: (j: J) => K,
    kl: (k: K) => L,
    lm: (l: L) => M,
    mn: (m: M) => N,
    no: (n: N) => O,
    op: (o: O) => P,
    pq: (p: P) => Q,
    qr: (q: Q) => R,
    rs: (r: R) => S,
    st: (s: S) => T,
    tu: (s: T) => Effect<_R, _E, _A>
  ): EffectGen<_R, _E, _A>
}

Added in v1.0.0

Blocked (interface)

Signature

export interface Blocked<R, E, A> extends Effect<R, E, A> {
  readonly _tag: 'Blocked'
  readonly i0: RequestBlock<R>
  readonly i1: Effect<R, E, A>
}

Added in v1.0.0

Effect (interface)

The Effect interface defines a value that lazily describes a workflow or job. The workflow requires some context R, and may fail with an error of type E, or succeed with a value of type A.

Effect values model resourceful interaction with the outside world, including synchronous, asynchronous, concurrent, and parallel interaction. They use a fiber-based concurrency model, with built-in support for scheduling, fine-grained interruption, structured concurrency, and high scalability.

To run an Effect value, you need a Runtime, which is a type that is capable of executing Effect values.

Signature

export interface Effect<R, E, A> extends Effect.Variance<R, E, A>, Equal.Equal, Pipeable, Inspectable {
  readonly [Unify.typeSymbol]?: unknown
  readonly [Unify.unifySymbol]?: EffectUnify<this>
  readonly [Unify.blacklistSymbol]?: EffectUnifyBlacklist
}

Added in v1.0.0

EffectGen (interface)

Signature

export interface EffectGen<R, E, A> {
  readonly _R: () => R
  readonly _E: () => E
  readonly _A: () => A
  readonly value: Effect<R, E, A>

  [Symbol.iterator](): Generator<EffectGen<R, E, A>, A>
}

Added in v1.0.0

EffectUnify (interface)

Signature

export interface EffectUnify<A extends { [Unify.typeSymbol]?: any }>
  extends Either.EitherUnify<A>,
    Option.OptionUnify<A>,
    Context.TagUnify<A> {
  Effect?: () => A[Unify.typeSymbol] extends Effect<infer R0, infer E0, infer A0> | infer _ ? Effect<R0, E0, A0> : never
}

Added in v1.0.0

EffectUnifyBlacklist (interface)

Signature

export interface EffectUnifyBlacklist {
  Tag?: true
  Option?: true
  Either?: true
}

Added in v1.0.0

optionality

fromNullable

Returns an effect that errors with NoSuchElementException if the value is null or undefined, otherwise succeeds with the value.

Signature

export declare const fromNullable: <A>(value: A) => Effect<never, Cause.NoSuchElementException, NonNullable<A>>

Added in v1.0.0

optionFromOptional

Wraps the success value of this effect with Option.some, and maps Cause.NoSuchElementException to Option.none.

Signature

export declare const optionFromOptional: <R, E, A>(
  self: Effect<R, E, A>
) => Effect<R, Exclude<E, Cause.NoSuchElementException>, Option.Option<A>>

Added in v1.0.0

random

random

Retreives the Random service from the context.

Signature

export declare const random: Effect<never, never, Random.Random>

Added in v1.0.0

randomWith

Retreives the Random service from the context and uses it to run the specified workflow.

Signature

export declare const randomWith: <R, E, A>(f: (random: Random.Random) => Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

refinements

isEffect

This function returns true if the specified value is an Effect value, false otherwise.

This function can be useful for checking the type of a value before attempting to operate on it as an Effect value. For example, you could use isEffect to check the type of a value before using it as an argument to a function that expects an Effect value.

Signature

export declare const isEffect: (u: unknown) => u is Effect<unknown, unknown, unknown>

Added in v1.0.0

repetition / recursion

forever

Repeats this effect forever (until the first error).

Signature

export declare const forever: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, never>

Added in v1.0.0

iterate

Iterates with the specified effectual function. The moral equivalent of:

let s = initial

while (cont(s)) {
  s = body(s)
}

return s

Signature

export declare const iterate: <Z, R, E>(
  initial: Z,
  options: { readonly while: (z: Z) => boolean; readonly body: (z: Z) => Effect<R, E, Z> }
) => Effect<R, E, Z>

Added in v1.0.0

loop

Loops with the specified effectual function, collecting the results into a list. The moral equivalent of:

let s = initial
let as = [] as readonly A[]

while (cont(s)) {
  as = [body(s), ...as]
  s = inc(s)
}

A.reverse(as)

Signature

export declare const loop: {
  <Z, R, E, A>(
    initial: Z,
    options: {
      readonly while: (z: Z) => boolean
      readonly step: (z: Z) => Z
      readonly body: (z: Z) => Effect<R, E, A>
      readonly discard?: false | undefined
    }
  ): Effect<R, E, A[]>
  <Z, R, E, A>(
    initial: Z,
    options: {
      readonly while: (z: Z) => boolean
      readonly step: (z: Z) => Z
      readonly body: (z: Z) => Effect<R, E, A>
      readonly discard: true
    }
  ): Effect<R, E, void>
}

Added in v1.0.0

repeat

Returns a new effect that repeats this effect according to the specified schedule or until the first failure. Scheduled recurrences are in addition to the first execution, so that io.repeat(Schedule.once) yields an effect that executes io, and then if that succeeds, executes io an additional time.

Signature

export declare const repeat: {
  <R1, A extends A0, A0, B>(schedule: Schedule.Schedule<R1, A, B>): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R1 | R, E, B>
  <R, E, A extends A0, A0, R1, B>(self: Effect<R, E, A>, schedule: Schedule.Schedule<R1, A0, B>): Effect<R | R1, E, B>
}

Added in v1.0.0

repeatN

Returns a new effect that repeats this effect the specified number of times or until the first failure. Repeats are in addition to the first execution, so that io.repeatN(1) yields an effect that executes io, and then if that succeeds, executes io an additional time.

Signature

export declare const repeatN: {
  (n: number): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, n: number): Effect<R, E, A>
}

Added in v1.0.0

repeatOrElse

Returns a new effect that repeats this effect according to the specified schedule or until the first failure, at which point, the failure value and schedule output are passed to the specified handler.

Scheduled recurrences are in addition to the first execution, so that pipe(effect, Effect.repeat(Schedule.once())) yields an effect that executes effect, and then if that succeeds, executes effect an additional time.

Signature

export declare const repeatOrElse: {
  <R2, A extends A0, A0, B, E, R3, E2>(
    schedule: Schedule.Schedule<R2, A, B>,
    orElse: (error: E, option: Option.Option<B>) => Effect<R3, E2, B>
  ): <R>(self: Effect<R, E, A>) => Effect<R2 | R3 | R, E2, B>
  <R, E, A extends A0, A0, R2, B, R3, E2>(
    self: Effect<R, E, A>,
    schedule: Schedule.Schedule<R2, A0, B>,
    orElse: (error: E, option: Option.Option<B>) => Effect<R3, E2, B>
  ): Effect<R | R2 | R3, E2, B>
}

Added in v1.0.0

repeatUntil

Repeats this effect until its value satisfies the specified predicate or until the first failure.

Signature

export declare const repeatUntil: {
  <A, B extends A>(f: Refinement<A, B>): <R, E>(self: Effect<R, E, A>) => Effect<R, E, B>
  <A>(f: Predicate<A>): <R, E>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A, B extends A>(self: Effect<R, E, A>, f: Predicate<A>): Effect<R, E, B>
  <R, E, A>(self: Effect<R, E, A>, f: Predicate<A>): Effect<R, E, A>
}

Added in v1.0.0

repeatUntilEffect

Repeats this effect until its value satisfies the specified effectful predicate or until the first failure.

Signature

export declare const repeatUntilEffect: {
  <A, R2, E2>(f: (a: A) => Effect<R2, E2, boolean>): <R, E>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, A>
  <R, E, A, R2, E2>(self: Effect<R, E, A>, f: (a: A) => Effect<R2, E2, boolean>): Effect<R | R2, E | E2, A>
}

Added in v1.0.0

repeatWhile

Repeats this effect while its value satisfies the specified effectful predicate or until the first failure.

Signature

export declare const repeatWhile: {
  <A>(f: Predicate<A>): <R, E>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, f: Predicate<A>): Effect<R, E, A>
}

Added in v1.0.0

repeatWhileEffect

Repeats this effect while its value satisfies the specified effectful predicate or until the first failure.

Signature

export declare const repeatWhileEffect: {
  <R1, A, E2>(f: (a: A) => Effect<R1, E2, boolean>): <R, E>(self: Effect<R, E, A>) => Effect<R1 | R, E2 | E, A>
  <R, E, R1, A, E2>(self: Effect<R, E, A>, f: (a: A) => Effect<R1, E2, boolean>): Effect<R | R1, E | E2, A>
}

Added in v1.0.0

schedule

Runs this effect according to the specified schedule.

See scheduleFrom for a variant that allows the schedule’s decision to depend on the result of this effect.

Signature

export declare const schedule: {
  <R2, Out>(schedule: Schedule.Schedule<R2, unknown, Out>): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E, Out>
  <R, E, A, R2, Out>(self: Effect<R, E, A>, schedule: Schedule.Schedule<R2, unknown, Out>): Effect<R | R2, E, Out>
}

Added in v1.0.0

scheduleForked

Runs this effect according to the specified schedule in a new fiber attached to the current scope.

Signature

export declare const scheduleForked: {
  <R2, Out>(schedule: Schedule.Schedule<R2, unknown, Out>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<Scope.Scope | R2 | R, never, Fiber.RuntimeFiber<E, Out>>
  <R, E, A, R2, Out>(self: Effect<R, E, A>, schedule: Schedule.Schedule<R2, unknown, Out>): Effect<
    Scope.Scope | R | R2,
    never,
    Fiber.RuntimeFiber<E, Out>
  >
}

Added in v1.0.0

scheduleFrom

Runs this effect according to the specified schedule starting from the specified input value.

Signature

export declare const scheduleFrom: {
  <R2, In, Out>(initial: In, schedule: Schedule.Schedule<R2, In, Out>): <R, E>(
    self: Effect<R, E, In>
  ) => Effect<R2 | R, E, Out>
  <R, E, In, R2, Out>(self: Effect<R, E, In>, initial: In, schedule: Schedule.Schedule<R2, In, Out>): Effect<
    R | R2,
    E,
    Out
  >
}

Added in v1.0.0

whileLoop

Signature

export declare const whileLoop: <R, E, A>(options: {
  readonly while: LazyArg<boolean>
  readonly body: LazyArg<Effect<R, E, A>>
  readonly step: (a: A) => void
}) => Effect<R, E, void>

Added in v1.0.0

requests & batching

blocked

Signature

export declare const blocked: <R, E, A>(
  blockedRequests: RequestBlock<R>,
  _continue: Effect<R, E, A>
) => Blocked<R, E, A>

Added in v1.0.0

cacheRequestResult

Signature

export declare const cacheRequestResult: <A extends Request.Request<any, any>>(
  request: A,
  result: Request.Request.Result<A>
) => Effect<never, never, void>

Added in v1.0.0

flatMapStep

Signature

export declare const flatMapStep: <R, E, A, R1, E1, B>(
  self: Effect<R, E, A>,
  f: (step: Exit.Exit<E, A> | Blocked<R, E, A>) => Effect<R1, E1, B>
) => Effect<R | R1, E1, B>

Added in v1.0.0

request

Signature

export declare const request: <
  A extends Request.Request<any, any>,
  Ds extends RequestResolver<A, never> | Effect<any, any, RequestResolver<A, never>>
>(
  request: A,
  dataSource: Ds
) => Effect<
  [Ds] extends [Effect<any, any, any>] ? Effect.Context<Ds> : never,
  Request.Request.Error<A>,
  Request.Request.Success<A>
>

Added in v1.0.0

runRequestBlock

Signature

export declare const runRequestBlock: <R>(blockedRequests: RequestBlock<R>) => Blocked<R, never, void>

Added in v1.0.0

setRequestBatching

Signature

export declare const setRequestBatching: (requestBatching: boolean) => Layer.Layer<never, never, never>

Added in v1.0.0

setRequestCache

Signature

export declare const setRequestCache: {
  <R, E>(cache: Effect<R, E, Request.Cache>): Layer.Layer<Exclude<R, Scope.Scope>, E, never>
  (cache: Request.Cache): Layer.Layer<never, never, never>
}

Added in v1.0.0

setRequestCaching

Signature

export declare const setRequestCaching: (requestCaching: boolean) => Layer.Layer<never, never, never>

Added in v1.0.0

step

Signature

export declare const step: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, Exit.Exit<E, A> | Blocked<R, E, A>>

Added in v1.0.0

withRequestBatching

Signature

export declare const withRequestBatching: {
  (requestBatching: boolean): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, requestBatching: boolean): Effect<R, E, A>
}

Added in v1.0.0

withRequestCache

Signature

export declare const withRequestCache: {
  (cache: Request.Cache): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, cache: Request.Cache): Effect<R, E, A>
}

Added in v1.0.0

withRequestCaching

Signature

export declare const withRequestCaching: {
  (strategy: boolean): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, strategy: boolean): Effect<R, E, A>
}

Added in v1.0.0

runtime

getRuntimeFlags

Retrieves an effect that succeeds with the current runtime flags, which govern behavior and features of the runtime system.

Signature

export declare const getRuntimeFlags: Effect<never, never, RuntimeFlags.RuntimeFlags>

Added in v1.0.0

patchRuntimeFlags

Signature

export declare const patchRuntimeFlags: (patch: RuntimeFlagsPatch.RuntimeFlagsPatch) => Effect<never, never, void>

Added in v1.0.0

runtime

Returns an effect that accesses the runtime, which can be used to (unsafely) execute tasks. This is useful for integration with legacy code that must call back into Effect code.

Signature

export declare const runtime: <R>() => Effect<R, never, Runtime.Runtime<R>>

Added in v1.0.0

withRuntimeFlagsPatch

Signature

export declare const withRuntimeFlagsPatch: {
  (update: RuntimeFlagsPatch.RuntimeFlagsPatch): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, update: RuntimeFlagsPatch.RuntimeFlagsPatch): Effect<R, E, A>
}

Added in v1.0.0

withRuntimeFlagsPatchScoped

Signature

export declare const withRuntimeFlagsPatchScoped: (
  update: RuntimeFlagsPatch.RuntimeFlagsPatch
) => Effect<Scope.Scope, never, void>

Added in v1.0.0

scheduler

setScheduler

Signature

export declare const setScheduler: (scheduler: Scheduler.Scheduler) => Layer.Layer<never, never, never>

Added in v1.0.0

withScheduler

Sets the provided scheduler for usage in the wrapped effect

Signature

export declare const withScheduler: {
  (scheduler: Scheduler.Scheduler): <R, E, B>(self: Effect<R, E, B>) => Effect<R, E, B>
  <R, E, B>(self: Effect<R, E, B>, scheduler: Scheduler.Scheduler): Effect<R, E, B>
}

Added in v1.0.0

scoping, resources & finalization

acquireRelease

This function constructs a scoped resource from an acquire and release Effect value.

If the acquire Effect value successfully completes execution, then the release Effect value will be added to the finalizers associated with the scope of this Effect value, and it is guaranteed to be run when the scope is closed.

The acquire and release Effect values will be run uninterruptibly. Additionally, the release Effect value may depend on the Exit value specified when the scope is closed.

Signature

export declare const acquireRelease: {
  <A, R2, X>(release: (a: A, exit: Exit.Exit<unknown, unknown>) => Effect<R2, never, X>): <R, E>(
    acquire: Effect<R, E, A>
  ) => Effect<Scope.Scope | R2 | R, E, A>
  <R, E, A, R2, X>(
    acquire: Effect<R, E, A>,
    release: (a: A, exit: Exit.Exit<unknown, unknown>) => Effect<R2, never, X>
  ): Effect<Scope.Scope | R | R2, E, A>
}

Added in v1.0.0

acquireReleaseInterruptible

This function constructs a scoped resource from an acquire and release Effect value.

If the acquire Effect value successfully completes execution, then the release Effect value will be added to the finalizers associated with the scope of this Effect value, and it is guaranteed to be run when the scope is closed.

The acquire Effect values will be run interruptibly. The release Effect values will be run uninterruptibly.

Additionally, the release Effect value may depend on the Exit value specified when the scope is closed.

Signature

export declare const acquireReleaseInterruptible: {
  <A, R2, X>(release: (exit: Exit.Exit<unknown, unknown>) => Effect<R2, never, X>): <R, E>(
    acquire: Effect<R, E, A>
  ) => Effect<Scope.Scope | R2 | R, E, A>
  <R, E, A, R2, X>(
    acquire: Effect<R, E, A>,
    release: (exit: Exit.Exit<unknown, unknown>) => Effect<R2, never, X>
  ): Effect<Scope.Scope | R | R2, E, A>
}

Added in v1.0.0

acquireUseRelease

This function is used to ensure that an Effect value that represents the acquisition of a resource (for example, opening a file, launching a thread, etc.) will not be interrupted, and that the resource will always be released when the Effect value completes execution.

acquireUseRelease does the following:

  1. Ensures that the Effect value that acquires the resource will not be interrupted. Note that acquisition may still fail due to internal reasons (such as an uncaught exception).
  2. Ensures that the release Effect value will not be interrupted, and will be executed as long as the acquisition Effect value successfully acquires the resource.

During the time period between the acquisition and release of the resource, the use Effect value will be executed.

If the release Effect value fails, then the entire Effect value will fail, even if the use Effect value succeeds. If this fail-fast behavior is not desired, errors produced by the release Effect value can be caught and ignored.

Signature

export declare const acquireUseRelease: {
  <A, R2, E2, A2, R3, X>(
    use: (a: A) => Effect<R2, E2, A2>,
    release: (a: A, exit: Exit.Exit<E2, A2>) => Effect<R3, never, X>
  ): <R, E>(acquire: Effect<R, E, A>) => Effect<R2 | R3 | R, E2 | E, A2>
  <R, E, A, R2, E2, A2, R3, X>(
    acquire: Effect<R, E, A>,
    use: (a: A) => Effect<R2, E2, A2>,
    release: (a: A, exit: Exit.Exit<E2, A2>) => Effect<R3, never, X>
  ): Effect<R | R2 | R3, E | E2, A2>
}

Added in v1.0.0

addFinalizer

This function adds a finalizer to the scope of the calling Effect value. The finalizer is guaranteed to be run when the scope is closed, and it may depend on the Exit value that the scope is closed with.

Signature

export declare const addFinalizer: <R, X>(
  finalizer: (exit: Exit.Exit<unknown, unknown>) => Effect<R, never, X>
) => Effect<Scope.Scope | R, never, void>

Added in v1.0.0

ensuring

Returns an effect that, if this effect starts execution, then the specified finalizer is guaranteed to be executed, whether this effect succeeds, fails, or is interrupted.

For use cases that need access to the effect’s result, see onExit.

Finalizers offer very powerful guarantees, but they are low-level, and should generally not be used for releasing resources. For higher-level logic built on ensuring, see the acquireRelease family of methods.

Signature

export declare const ensuring: {
  <R1, X>(finalizer: Effect<R1, never, X>): <R, E, A>(self: Effect<R, E, A>) => Effect<R1 | R, E, A>
  <R, E, A, R1, X>(self: Effect<R, E, A>, finalizer: Effect<R1, never, X>): Effect<R | R1, E, A>
}

Added in v1.0.0

finalizersMask

Signature

export declare const finalizersMask: (
  strategy: ExecutionStrategy
) => <R, E, A>(
  self: (restore: <R1, E1, A1>(self: Effect<R1, E1, A1>) => Effect<R1, E1, A1>) => Effect<R, E, A>
) => Effect<R, E, A>

Added in v1.0.0

onError

Runs the specified effect if this effect fails, providing the error to the effect if it exists. The provided effect will not be interrupted.

Signature

export declare const onError: {
  <E, R2, X>(cleanup: (cause: Cause.Cause<E>) => Effect<R2, never, X>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E, A>
  <R, A, E, R2, X>(self: Effect<R, E, A>, cleanup: (cause: Cause.Cause<E>) => Effect<R2, never, X>): Effect<
    R | R2,
    E,
    A
  >
}

Added in v1.0.0

onExit

Ensures that a cleanup functions runs, whether this effect succeeds, fails, or is interrupted.

Signature

export declare const onExit: {
  <E, A, R2, X>(cleanup: (exit: Exit.Exit<E, A>) => Effect<R2, never, X>): <R>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E, A>
  <R, E, A, R2, X>(self: Effect<R, E, A>, cleanup: (exit: Exit.Exit<E, A>) => Effect<R2, never, X>): Effect<
    R | R2,
    E,
    A
  >
}

Added in v1.0.0

parallelFinalizers

Signature

export declare const parallelFinalizers: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

scope

Signature

export declare const scope: Effect<Scope.Scope, never, Scope.Scope>

Added in v1.0.0

scopeWith

Accesses the current scope and uses it to perform the specified effect.

Signature

export declare const scopeWith: <R, E, A>(f: (scope: Scope.Scope) => Effect<R, E, A>) => Effect<Scope.Scope | R, E, A>

Added in v1.0.0

scoped

Scopes all resources uses in this workflow to the lifetime of the workflow, ensuring that their finalizers are run as soon as this workflow completes execution, whether by success, failure, or interruption.

Signature

export declare const scoped: <R, E, A>(effect: Effect<R, E, A>) => Effect<Exclude<R, Scope.Scope>, E, A>

Added in v1.0.0

sequentialFinalizers

Returns a new scoped workflow that runs finalizers added to the scope of this workflow sequentially in the reverse of the order in which they were added. Note that finalizers are run sequentially by default so this only has meaning if used within a scope where finalizers are being run in parallel.

Signature

export declare const sequentialFinalizers: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

using

Scopes all resources acquired by resource to the lifetime of use without effecting the scope of any resources acquired by use.

Signature

export declare const using: {
  <A, R2, E2, A2>(use: (a: A) => Effect<R2, E2, A2>): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R2 | Exclude<R, Scope.Scope>, E2 | E, A2>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, use: (a: A) => Effect<R2, E2, A2>): Effect<
    R2 | Exclude<R, Scope.Scope>,
    E | E2,
    A2
  >
}

Added in v1.0.0

withEarlyRelease

Returns a new scoped workflow that returns the result of this workflow as well as a finalizer that can be run to close the scope of this workflow.

Signature

export declare const withEarlyRelease: <R, E, A>(
  self: Effect<R, E, A>
) => Effect<Scope.Scope | R, E, readonly [Effect<never, never, void>, A]>

Added in v1.0.0

semaphore

Permit (interface)

Signature

export interface Permit {
  readonly index: number
}

Added in v1.0.0

Semaphore (interface)

Signature

export interface Semaphore {
  readonly withPermits: (permits: number) => <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  readonly take: (permits: number) => Effect<never, never, number>
  readonly release: (permits: number) => Effect<never, never, void>
}

Added in v1.0.0

makeSemaphore

Creates a new Semaphore

Signature

export declare const makeSemaphore: (permits: number) => Effect<never, never, Semaphore>

Added in v1.0.0

unsafeMakeSemaphore

Unsafely creates a new Semaphore

Signature

export declare const unsafeMakeSemaphore: (permits: number) => Semaphore

Added in v1.0.0

sequencing

flatMap

This function is a pipeable operator that maps over an Effect value, flattening the result of the mapping function into a new Effect value.

Signature

export declare const flatMap: {
  <A, R1, E1, B>(f: (a: A) => Effect<R1, E1, B>): <R, E>(self: Effect<R, E, A>) => Effect<R1 | R, E1 | E, B>
  <R, E, A, R1, E1, B>(self: Effect<R, E, A>, f: (a: A) => Effect<R1, E1, B>): Effect<R | R1, E | E1, B>
}

Added in v1.0.0

flatten

Signature

export declare const flatten: <R, E, R1, E1, A>(self: Effect<R, E, Effect<R1, E1, A>>) => Effect<R | R1, E | E1, A>

Added in v1.0.0

race

Returns an effect that races this effect with the specified effect, returning the first successful A from the faster side. If one effect succeeds, the other will be interrupted. If neither succeeds, then the effect will fail with some error.

Signature

export declare const race: {
  <R2, E2, A2>(that: Effect<R2, E2, A2>): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, A2 | A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, that: Effect<R2, E2, A2>): Effect<R | R2, E | E2, A | A2>
}

Added in v1.0.0

raceAll

Returns an effect that races this effect with all the specified effects, yielding the value of the first effect to succeed with a value. Losers of the race will be interrupted immediately

Signature

export declare const raceAll: <R, E, A>(effects: Iterable<Effect<R, E, A>>) => Effect<R, E, A>

Added in v1.0.0

raceFirst

Returns an effect that races this effect with the specified effect, yielding the first result to complete, whether by success or failure. If neither effect completes, then the composed effect will not complete.

WARNING: The raced effect will safely interrupt the “loser”, but will not resume until the loser has been cleanly terminated. If early return is desired, then instead of performing l raceFirst r, perform l.disconnect raceFirst r.disconnect, which disconnects left and right interrupt signal, allowing a fast return, with interruption performed in the background.

Signature

export declare const raceFirst: {
  <R2, E2, A2>(that: Effect<R2, E2, A2>): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, A2 | A>
  <R, E, A, R2, E2, A2>(self: Effect<R, E, A>, that: Effect<R2, E2, A2>): Effect<R | R2, E | E2, A | A2>
}

Added in v1.0.0

raceWith

Returns an effect that races this effect with the specified effect, calling the specified finisher as soon as one result or the other has been computed.

Signature

export declare const raceWith: {
  <E, A, R1, E1, A1, R2, E2, A2, R3, E3, A3>(
    other: Effect<R1, E1, A1>,
    options: {
      readonly onSelfDone: (exit: Exit.Exit<E, A>, fiber: Fiber.Fiber<E1, A1>) => Effect<R2, E2, A2>
      readonly onOtherDone: (exit: Exit.Exit<E1, A1>, fiber: Fiber.Fiber<E, A>) => Effect<R3, E3, A3>
    }
  ): <R>(self: Effect<R, E, A>) => Effect<R1 | R2 | R3 | R, E2 | E3, A2 | A3>
  <R, E, A, R1, E1, A1, R2, E2, A2, R3, E3, A3>(
    self: Effect<R, E, A>,
    other: Effect<R1, E1, A1>,
    options: {
      readonly onSelfDone: (exit: Exit.Exit<E, A>, fiber: Fiber.Fiber<E1, A1>) => Effect<R2, E2, A2>
      readonly onOtherDone: (exit: Exit.Exit<E1, A1>, fiber: Fiber.Fiber<E, A>) => Effect<R3, E3, A3>
    }
  ): Effect<R | R1 | R2 | R3, E2 | E3, A2 | A3>
}

Added in v1.0.0

summarized

Summarizes a effect by computing some value before and after execution, and then combining the values to produce a summary, together with the result of execution.

Signature

export declare const summarized: {
  <R2, E2, B, C>(summary: Effect<R2, E2, B>, f: (start: B, end: B) => C): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, readonly [C, A]>
  <R, E, A, R2, E2, B, C>(self: Effect<R, E, A>, summary: Effect<R2, E2, B>, f: (start: B, end: B) => C): Effect<
    R | R2,
    E | E2,
    readonly [C, A]
  >
}

Added in v1.0.0

tap

Signature

export declare const tap: {
  <A, X extends A, R2, E2, _>(f: (a: X) => Effect<R2, E2, _>): <R, E>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, A>
  <R, E, A, X extends A, R2, E2, _>(self: Effect<R, E, A>, f: (a: X) => Effect<R2, E2, _>): Effect<R | R2, E | E2, A>
}

Added in v1.0.0

tapBoth

Returns an effect that effectfully “peeks” at the failure or success of this effect.

Signature

export declare const tapBoth: {
  <E, XE extends E, A, XA extends A, R2, E2, X, R3, E3, X1>(options: {
    readonly onFailure: (e: XE) => Effect<R2, E2, X>
    readonly onSuccess: (a: XA) => Effect<R3, E3, X1>
  }): <R>(self: Effect<R, E, A>) => Effect<R2 | R3 | R, E | E2 | E3, A>
  <R, E, A, XE extends E, XA extends A, R2, E2, X, R3, E3, X1>(
    self: Effect<R, E, A>,
    options: { readonly onFailure: (e: XE) => Effect<R2, E2, X>; readonly onSuccess: (a: XA) => Effect<R3, E3, X1> }
  ): Effect<R | R2 | R3, E | E2 | E3, A>
}

Added in v1.0.0

tapDefect

Returns an effect that effectually “peeks” at the defect of this effect.

Signature

export declare const tapDefect: {
  <R2, E2, X>(f: (cause: Cause.Cause<never>) => Effect<R2, E2, X>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E2 | E, A>
  <R, E, A, R2, E2, X>(self: Effect<R, E, A>, f: (cause: Cause.Cause<never>) => Effect<R2, E2, X>): Effect<
    R | R2,
    E | E2,
    A
  >
}

Added in v1.0.0

tapError

Returns an effect that effectfully “peeks” at the failure of this effect.

Signature

export declare const tapError: {
  <E, XE extends E, R2, E2, X>(f: (e: XE) => Effect<R2, E2, X>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E | E2, A>
  <R, E, XE extends E, A, R2, E2, X>(self: Effect<R, E, A>, f: (e: XE) => Effect<R2, E2, X>): Effect<R | R2, E | E2, A>
}

Added in v1.0.0

tapErrorCause

Returns an effect that effectually “peeks” at the cause of the failure of this effect.

Signature

export declare const tapErrorCause: {
  <E, XE extends E, R2, E2, X>(f: (cause: Cause.Cause<XE>) => Effect<R2, E2, X>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E | E2, A>
  <R, E, A, XE extends E, R2, E2, X>(self: Effect<R, E, A>, f: (cause: Cause.Cause<XE>) => Effect<R2, E2, X>): Effect<
    R | R2,
    E | E2,
    A
  >
}

Added in v1.0.0

tapErrorTag

Returns an effect that effectfully “peeks” at the specific tagged failure of this effect.

Signature

export declare const tapErrorTag: {
  <K extends E extends { _tag: string } ? E['_tag'] : never, E, R1, E1, A1>(
    k: K,
    f: (e: Extract<E, { _tag: K }>) => Effect<R1, E1, A1>
  ): <R, A>(self: Effect<R, E, A>) => Effect<R1 | R, E | E1, A>
  <R, E, A, K extends E extends { _tag: string } ? E['_tag'] : never, R1, E1, A1>(
    self: Effect<R, E, A>,
    k: K,
    f: (e: Extract<E, { _tag: K }>) => Effect<R1, E1, A1>
  ): Effect<R | R1, E | E1, A>
}

Added in v1.0.0

supervision & fibers

awaitAllChildren

Returns a new effect that will not succeed with its value before first waiting for the end of all child fibers forked by the effect.

Signature

export declare const awaitAllChildren: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

daemonChildren

Returns a new workflow that will not supervise any fibers forked by this workflow.

Signature

export declare const daemonChildren: <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

descriptor

Constructs an effect with information about the current Fiber.

Signature

export declare const descriptor: Effect<never, never, Fiber.Fiber.Descriptor>

Added in v1.0.0

descriptorWith

Constructs an effect based on information about the current Fiber.

Signature

export declare const descriptorWith: <R, E, A>(
  f: (descriptor: Fiber.Fiber.Descriptor) => Effect<R, E, A>
) => Effect<R, E, A>

Added in v1.0.0

diffFiberRefs

Returns a new workflow that executes this one and captures the changes in FiberRef values.

Signature

export declare const diffFiberRefs: <R, E, A>(
  self: Effect<R, E, A>
) => Effect<R, E, readonly [FiberRefsPatch.FiberRefsPatch, A]>

Added in v1.0.0

ensuringChild

Acts on the children of this fiber (collected into a single fiber), guaranteeing the specified callback will be invoked, whether or not this effect succeeds.

Signature

export declare const ensuringChild: {
  <R2, X>(f: (fiber: Fiber.Fiber<any, ReadonlyArray<unknown>>) => Effect<R2, never, X>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R2 | R, E, A>
  <R, E, A, R2, X>(
    self: Effect<R, E, A>,
    f: (fiber: Fiber.Fiber<any, ReadonlyArray<unknown>>) => Effect<R2, never, X>
  ): Effect<R | R2, E, A>
}

Added in v1.0.0

ensuringChildren

Acts on the children of this fiber, guaranteeing the specified callback will be invoked, whether or not this effect succeeds.

Signature

export declare const ensuringChildren: {
  <R1, X>(children: (fibers: ReadonlyArray<Fiber.RuntimeFiber<any, any>>) => Effect<R1, never, X>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R1 | R, E, A>
  <R, E, A, R1, X>(
    self: Effect<R, E, A>,
    children: (fibers: ReadonlyArray<Fiber.RuntimeFiber<any, any>>) => Effect<R1, never, X>
  ): Effect<R | R1, E, A>
}

Added in v1.0.0

fiberId

Signature

export declare const fiberId: Effect<never, never, FiberId.FiberId>

Added in v1.0.0

fiberIdWith

Signature

export declare const fiberIdWith: <R, E, A>(f: (descriptor: FiberId.Runtime) => Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

fork

Returns an effect that forks this effect into its own separate fiber, returning the fiber immediately, without waiting for it to begin executing the effect.

You can use the fork method whenever you want to execute an effect in a new fiber, concurrently and without “blocking” the fiber executing other effects. Using fibers can be tricky, so instead of using this method directly, consider other higher-level methods, such as raceWith, zipPar, and so forth.

The fiber returned by this method has methods to interrupt the fiber and to wait for it to finish executing the effect. See Fiber for more information.

Whenever you use this method to launch a new fiber, the new fiber is attached to the parent fiber’s scope. This means when the parent fiber terminates, the child fiber will be terminated as well, ensuring that no fibers leak. This behavior is called “auto supervision”, and if this behavior is not desired, you may use the forkDaemon or forkIn methods.

Signature

export declare const fork: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Fiber.RuntimeFiber<E, A>>

Added in v1.0.0

forkAll

Returns an effect that forks all of the specified values, and returns a composite fiber that produces a list of their results, in order.

Signature

export declare const forkAll: {
  (options?: { readonly discard?: false }): <R, E, A>(
    effects: Iterable<Effect<R, E, A>>
  ) => Effect<R, never, Fiber.Fiber<E, A[]>>
  (options: { readonly discard: true }): <R, E, A>(effects: Iterable<Effect<R, E, A>>) => Effect<R, never, void>
  <R, E, A>(effects: Iterable<Effect<R, E, A>>, options?: { readonly discard?: false }): Effect<
    R,
    never,
    Fiber.Fiber<E, A[]>
  >
  <R, E, A>(effects: Iterable<Effect<R, E, A>>, options: { readonly discard: true }): Effect<R, never, void>
}

Added in v1.0.0

forkDaemon

Forks the effect into a new fiber attached to the global scope. Because the new fiber is attached to the global scope, when the fiber executing the returned effect terminates, the forked fiber will continue running.

Signature

export declare const forkDaemon: <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Fiber.RuntimeFiber<E, A>>

Added in v1.0.0

forkIn

Forks the effect in the specified scope. The fiber will be interrupted when the scope is closed.

Signature

export declare const forkIn: {
  (scope: Scope.Scope): <R, E, A>(self: Effect<R, E, A>) => Effect<R, never, Fiber.RuntimeFiber<E, A>>
  <R, E, A>(self: Effect<R, E, A>, scope: Scope.Scope): Effect<R, never, Fiber.RuntimeFiber<E, A>>
}

Added in v1.0.0

forkScoped

Forks the fiber in a Scope, interrupting it when the scope is closed.

Signature

export declare const forkScoped: <R, E, A>(
  self: Effect<R, E, A>
) => Effect<Scope.Scope | R, never, Fiber.RuntimeFiber<E, A>>

Added in v1.0.0

forkWithErrorHandler

Like fork but handles an error with the provided handler.

Signature

export declare const forkWithErrorHandler: {
  <E, X>(handler: (e: E) => Effect<never, never, X>): <R, A>(
    self: Effect<R, E, A>
  ) => Effect<R, never, Fiber.RuntimeFiber<E, A>>
  <R, E, A, X>(self: Effect<R, E, A>, handler: (e: E) => Effect<never, never, X>): Effect<
    R,
    never,
    Fiber.RuntimeFiber<E, A>
  >
}

Added in v1.0.0

fromFiber

Creates an Effect value that represents the exit value of the specified fiber.

Signature

export declare const fromFiber: <E, A>(fiber: Fiber.Fiber<E, A>) => Effect<never, E, A>

Added in v1.0.0

fromFiberEffect

Creates an Effect value that represents the exit value of the specified fiber.

Signature

export declare const fromFiberEffect: <R, E, A>(fiber: Effect<R, E, Fiber.Fiber<E, A>>) => Effect<R, E, A>

Added in v1.0.0

supervised

Returns an effect with the behavior of this one, but where all child fibers forked in the effect are reported to the specified supervisor.

Signature

export declare const supervised: {
  <X>(supervisor: Supervisor.Supervisor<X>): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A, X>(self: Effect<R, E, A>, supervisor: Supervisor.Supervisor<X>): Effect<R, E, A>
}

Added in v1.0.0

transplant

Transplants specified effects so that when those effects fork other effects, the forked effects will be governed by the scope of the fiber that executes this effect.

This can be used to “graft” deep grandchildren onto a higher-level scope, effectively extending their lifespans into the parent scope.

Signature

export declare const transplant: <R, E, A>(
  f: (grafter: <R2, E2, A2>(effect: Effect<R2, E2, A2>) => Effect<R2, E2, A2>) => Effect<R, E, A>
) => Effect<R, E, A>

Added in v1.0.0

withConcurrency

Signature

export declare const withConcurrency: {
  (concurrency: number | 'unbounded'): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, concurrency: number | 'unbounded'): Effect<R, E, A>
}

Added in v1.0.0

symbols

EffectTypeId

Signature

export declare const EffectTypeId: typeof EffectTypeId

Added in v1.0.0

EffectTypeId (type alias)

Signature

export type EffectTypeId = typeof EffectTypeId

Added in v1.0.0

tracing

annotateCurrentSpan

Adds an annotation to the current span if available

Signature

export declare const annotateCurrentSpan: {
  (key: string, value: Tracer.AttributeValue): Effect<never, never, void>
  (values: Record<string, Tracer.AttributeValue>): Effect<never, never, void>
}

Added in v1.0.0

annotateSpans

Adds an annotation to each span in this effect.

Signature

export declare const annotateSpans: {
  (key: string, value: Tracer.AttributeValue): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  (values: Record<string, Tracer.AttributeValue>): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, key: string, value: Tracer.AttributeValue): Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, values: Record<string, Tracer.AttributeValue>): Effect<R, E, A>
}

Added in v1.0.0

currentParentSpan

Signature

export declare const currentParentSpan: Effect<never, never, Option.Option<Tracer.ParentSpan>>

Added in v1.0.0

currentSpan

Signature

export declare const currentSpan: Effect<never, never, Option.Option<Tracer.Span>>

Added in v1.0.0

linkSpans

For all spans in this effect, add a link with the provided span.

Signature

export declare const linkSpans: {
  (span: Tracer.ParentSpan, attributes?: Record<string, Tracer.AttributeValue>): <R, E, A>(
    self: Effect<R, E, A>
  ) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, span: Tracer.ParentSpan, attributes?: Record<string, Tracer.AttributeValue>): Effect<
    R,
    E,
    A
  >
}

Added in v1.0.0

makeSpan

Create a new span for tracing.

Signature

export declare const makeSpan: (
  name: string,
  options?: {
    readonly attributes?: Record<string, Tracer.AttributeValue>
    readonly links?: ReadonlyArray<Tracer.SpanLink>
    readonly parent?: Tracer.ParentSpan
    readonly root?: boolean
    readonly context?: Context.Context<never>
  }
) => Effect<never, never, Tracer.Span>

Added in v1.0.0

setParentSpan

Adds the provided span to the span stack.

Signature

export declare const setParentSpan: (span: Tracer.ParentSpan) => Layer.Layer<never, never, never>

Added in v1.0.0

setSpan

Create and add a span to the current span stack.

The span is ended when the Layer is released.

Signature

export declare const setSpan: (
  name: string,
  options?: {
    readonly attributes?: Record<string, Tracer.AttributeValue>
    readonly links?: ReadonlyArray<Tracer.SpanLink>
    readonly parent?: Tracer.ParentSpan
    readonly root?: boolean
    readonly context?: Context.Context<never>
  }
) => Layer.Layer<never, never, never>

Added in v1.0.0

setTracer

Create a Layer that sets the current Tracer

Signature

export declare const setTracer: (tracer: Tracer.Tracer) => Layer.Layer<never, never, never>

Added in v1.0.0

setTracerTiming

Signature

export declare const setTracerTiming: (enabled: boolean) => Layer.Layer<never, never, never>

Added in v1.0.0

spanAnnotations

Signature

export declare const spanAnnotations: Effect<never, never, HashMap.HashMap<string, Tracer.AttributeValue>>

Added in v1.0.0

Signature

export declare const spanLinks: Effect<never, never, Chunk.Chunk<Tracer.SpanLink>>

Added in v1.0.0

tracer

Signature

export declare const tracer: Effect<never, never, Tracer.Tracer>

Added in v1.0.0

tracerWith

Signature

export declare const tracerWith: <R, E, A>(f: (tracer: Tracer.Tracer) => Effect<R, E, A>) => Effect<R, E, A>

Added in v1.0.0

useSpan

Create a new span for tracing, and automatically close it when the effect completes.

The span is not added to the current span stack, so no child spans will be created for it.

Signature

export declare const useSpan: {
  <R, E, A>(name: string, evaluate: (span: Tracer.Span) => Effect<R, E, A>): Effect<R, E, A>
  <R, E, A>(
    name: string,
    options: {
      readonly attributes?: Record<string, Tracer.AttributeValue>
      readonly links?: ReadonlyArray<Tracer.SpanLink>
      readonly parent?: Tracer.ParentSpan
      readonly root?: boolean
      readonly context?: Context.Context<never>
    },
    evaluate: (span: Tracer.Span) => Effect<R, E, A>
  ): Effect<R, E, A>
}

Added in v1.0.0

useSpanScoped

Create a new span for tracing, and automatically close it when the Scope finalizes.

The span is not added to the current span stack, so no child spans will be created for it.

Signature

export declare const useSpanScoped: (
  name: string,
  options?: {
    readonly attributes?: Record<string, Tracer.AttributeValue>
    readonly links?: ReadonlyArray<Tracer.SpanLink>
    readonly parent?: Tracer.ParentSpan
    readonly root?: boolean
    readonly context?: Context.Context<never>
  }
) => Effect<Scope.Scope, never, Tracer.Span>

Added in v1.0.0

withParentSpan

Adds the provided span to the current span stack.

Signature

export declare const withParentSpan: {
  (span: Tracer.ParentSpan): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(self: Effect<R, E, A>, span: Tracer.ParentSpan): Effect<R, E, A>
}

Added in v1.0.0

withParentSpanScoped

Adds the provided span to the current span stack.

Signature

export declare const withParentSpanScoped: (span: Tracer.ParentSpan) => Effect<Scope.Scope, never, void>

Added in v1.0.0

withSpan

Wraps the effect with a new span for tracing.

Signature

export declare const withSpan: {
  (
    name: string,
    options?: {
      readonly attributes?: Record<string, Tracer.AttributeValue>
      readonly links?: ReadonlyArray<Tracer.SpanLink>
      readonly parent?: Tracer.ParentSpan
      readonly root?: boolean
      readonly context?: Context.Context<never>
    }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(
    self: Effect<R, E, A>,
    name: string,
    options?: {
      readonly attributes?: Record<string, Tracer.AttributeValue>
      readonly links?: ReadonlyArray<Tracer.SpanLink>
      readonly parent?: Tracer.ParentSpan
      readonly root?: boolean
      readonly context?: Context.Context<never>
    }
  ): Effect<R, E, A>
}

Added in v1.0.0

withSpanScoped

Create and add a span to the current span stack.

The span is ended when the Scope is finalized.

Signature

export declare const withSpanScoped: (
  name: string,
  options?: {
    readonly attributes?: Record<string, Tracer.AttributeValue>
    readonly links?: ReadonlyArray<Tracer.SpanLink>
    readonly parent?: Tracer.ParentSpan
    readonly root?: boolean
    readonly context?: Context.Context<never>
  }
) => Effect<Scope.Scope, never, void>

Added in v1.0.0

withTracer

Signature

export declare const withTracer: {
  (value: Tracer.Tracer): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, value: Tracer.Tracer): Effect<R, E, A>
}

Added in v1.0.0

withTracerScoped

Signature

export declare const withTracerScoped: (value: Tracer.Tracer) => Effect<Scope.Scope, never, void>

Added in v1.0.0

withTracerTiming

Signature

export declare const withTracerTiming: {
  (enabled: boolean): <R, E, A>(effect: Effect<R, E, A>) => Effect<R, E, A>
  <R, E, A>(effect: Effect<R, E, A>, enabled: boolean): Effect<R, E, A>
}

Added in v1.0.0

type lambdas

EffectTypeLambda (interface)

Signature

export interface EffectTypeLambda extends TypeLambda {
  readonly type: Effect<this['Out2'], this['Out1'], this['Target']>
}

Added in v1.0.0

unify

unified

Used to unify effects that would otherwise be Effect<A, B, C> | Effect<D, E, F>

Signature

export declare const unified: <Ret extends Effect<any, any, any>>(f: Ret) => Effect.Unify<Ret>

Added in v1.0.0

unifiedFn

Used to unify functions that would otherwise return Effect<A, B, C> | Effect<D, E, F>

Signature

export declare const unifiedFn: <Args extends readonly any[], Ret extends Effect<any, any, any>>(
  f: (...args: Args) => Ret
) => (...args: Args) => Effect.Unify<Ret>

Added in v1.0.0

utils

All (namespace)

Added in v1.0.0

EffectAny (type alias)

Signature

export type EffectAny = Effect<any, any, any>

Added in v1.0.0

ExtractMode (type alias)

Signature

export type ExtractMode<A> = [A] extends [{ mode: infer M }] ? M : 'default'

Added in v1.0.0

IsDiscard (type alias)

Signature

export type IsDiscard<A> = [Extract<A, { readonly discard: true }>] extends [never] ? false : true

Added in v1.0.0

Return (type alias)

Signature

export type Return<
  Arg extends Iterable<EffectAny> | Record<string, EffectAny>,
  O extends {
    readonly concurrency?: Concurrency
    readonly batching?: boolean | 'inherit'
    readonly discard?: boolean
    readonly mode?: 'default' | 'validate' | 'either'
  }
> = [Arg] extends [ReadonlyArray<EffectAny>]
  ? ReturnTuple<Arg, IsDiscard<O>, ExtractMode<O>>
  : [Arg] extends [Iterable<EffectAny>]
  ? ReturnIterable<Arg, IsDiscard<O>, ExtractMode<O>>
  : [Arg] extends [Record<string, EffectAny>]
  ? ReturnObject<Arg, IsDiscard<O>, ExtractMode<O>>
  : never

Added in v1.0.0

ReturnIterable (type alias)

Signature

export type ReturnIterable<T extends Iterable<EffectAny>, Discard extends boolean, Mode> = [T] extends [
  Iterable<Effect.Variance<infer R, infer E, infer A>>
]
  ? Effect<
      R,
      Mode extends 'either' ? never : Mode extends 'validate' ? Array<Option.Option<E>> : E,
      Discard extends true ? void : Mode extends 'either' ? Array<Either.Either<E, A>> : Array<A>
    >
  : never

Added in v1.0.0

ReturnObject (type alias)

Signature

export type ReturnObject<T, Discard extends boolean, Mode> = [T] extends [{ [K: string]: EffectAny }]
  ? Effect<
      keyof T extends never
        ? never
        : [T[keyof T]] extends [{ [EffectTypeId]: { _R: (_: never) => infer R } }]
        ? R
        : never,
      Mode extends 'either'
        ? never
        : keyof T extends never
        ? never
        : Mode extends 'validate'
        ? {
            -readonly [K in keyof T]: [T[K]] extends [Effect.Variance<infer _R, infer _E, infer _A>]
              ? Option.Option<_E>
              : never
          }
        : [T[keyof T]] extends [{ [EffectTypeId]: { _E: (_: never) => infer E } }]
        ? E
        : never,
      Discard extends true
        ? void
        : Mode extends 'either'
        ? {
            -readonly [K in keyof T]: [T[K]] extends [Effect.Variance<infer _R, infer _E, infer _A>]
              ? Either.Either<_E, _A>
              : never
          }
        : { -readonly [K in keyof T]: [T[K]] extends [Effect.Variance<infer _R, infer _E, infer _A>] ? _A : never }
    >
  : never

Added in v1.0.0

ReturnTuple (type alias)

Signature

export type ReturnTuple<T extends ReadonlyArray<unknown>, Discard extends boolean, Mode> = Effect<
  T[number] extends never ? never : [T[number]] extends [{ [EffectTypeId]: { _R: (_: never) => infer R } }] ? R : never,
  Mode extends 'either'
    ? never
    : T[number] extends never
    ? never
    : Mode extends 'validate'
    ? {
        -readonly [K in keyof T]: [T[K]] extends [Effect.Variance<infer _R, infer _E, infer _A>]
          ? Option.Option<_E>
          : never
      }
    : [T[number]] extends [{ [EffectTypeId]: { _E: (_: never) => infer E } }]
    ? E
    : never,
  Discard extends true
    ? void
    : T[number] extends never
    ? []
    : Mode extends 'either'
    ? {
        -readonly [K in keyof T]: [T[K]] extends [Effect.Variance<infer _R, infer _E, infer _A>]
          ? Either.Either<_E, _A>
          : never
      }
    : { -readonly [K in keyof T]: [T[K]] extends [Effect.Variance<infer _R, infer _E, infer _A>] ? _A : never }
> extends infer X
  ? X
  : never

Added in v1.0.0

Effect (namespace)

Added in v1.0.0

Variance (interface)

Signature

export interface Variance<R, E, A> {
  readonly [EffectTypeId]: {
    readonly _R: (_: never) => R
    readonly _E: (_: never) => E
    readonly _A: (_: never) => A
  }
}

Added in v1.0.0

Context (type alias)

Signature

export type Context<T extends Effect<any, any, any>> = [T] extends [Effect<infer _R, infer _E, infer _A>] ? _R : never

Added in v1.0.0

Error (type alias)

Signature

export type Error<T extends Effect<any, any, any>> = [T] extends [Effect<infer _R, infer _E, infer _A>] ? _E : never

Added in v1.0.0

Success (type alias)

Signature

export type Success<T extends Effect<any, any, any>> = [T] extends [Effect<infer _R, infer _E, infer _A>] ? _A : never

Added in v1.0.0

Unify (type alias)

Signature

export type Unify<Ret extends Effect<any, any, any>> = Effect<Context<Ret>, Error<Ret>, Success<Ret>>

Added in v1.0.0

MergeRecord (type alias)

Signature

export type MergeRecord<K, H> = {
  [k in keyof K | keyof H]: k extends keyof K ? K[k] : k extends keyof H ? H[k] : never
} extends infer X
  ? X
  : never

Added in v1.0.0

withMaxOpsBeforeYield

Sets the maximum number of operations before yield by the default schedulers

Signature

export declare const withMaxOpsBeforeYield: {
  (priority: number): <R, E, B>(self: Effect<R, E, B>) => Effect<R, E, B>
  <R, E, B>(self: Effect<R, E, B>, priority: number): Effect<R, E, B>
}

Added in v1.0.0

withSchedulingPriority

Sets the scheduling priority used when yielding

Signature

export declare const withSchedulingPriority: {
  (priority: number): <R, E, B>(self: Effect<R, E, B>) => Effect<R, E, B>
  <R, E, B>(self: Effect<R, E, B>, priority: number): Effect<R, E, B>
}

Added in v1.0.0

zipping

validate

Sequentially zips the this result with the specified result. Combines both Causes when both effects fail.

Signature

export declare const validate: {
  <R1, E1, B>(
    that: Effect<R1, E1, B>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R1 | R, E1 | E, [A, B]>
  <R, E, A, R1, E1, B>(
    self: Effect<R, E, A>,
    that: Effect<R1, E1, B>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): Effect<R | R1, E | E1, [A, B]>
}

Added in v1.0.0

validateWith

Sequentially zips this effect with the specified effect using the specified combiner function. Combines the causes in case both effect fail.

Signature

export declare const validateWith: {
  <A, R1, E1, B, C>(
    that: Effect<R1, E1, B>,
    f: (a: A, b: B) => C,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): <R, E>(self: Effect<R, E, A>) => Effect<R1 | R, E1 | E, C>
  <R, E, A, R1, E1, B, C>(
    self: Effect<R, E, A>,
    that: Effect<R1, E1, B>,
    f: (a: A, b: B) => C,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): Effect<R | R1, E | E1, C>
}

Added in v1.0.0

zip

Signature

export declare const zip: {
  <R2, E2, A2>(
    that: Effect<R2, E2, A2>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, [A, A2]>
  <R, E, A, R2, E2, A2>(
    self: Effect<R, E, A>,
    that: Effect<R2, E2, A2>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): Effect<R | R2, E | E2, [A, A2]>
}

Added in v1.0.0

zipLeft

Signature

export declare const zipLeft: {
  <R2, E2, A2>(
    that: Effect<R2, E2, A2>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, A>
  <R, E, A, R2, E2, A2>(
    self: Effect<R, E, A>,
    that: Effect<R2, E2, A2>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): Effect<R | R2, E | E2, A>
}

Added in v1.0.0

zipRight

Signature

export declare const zipRight: {
  <R2, E2, A2>(
    that: Effect<R2, E2, A2>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): <R, E, A>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, A2>
  <R, E, A, R2, E2, A2>(
    self: Effect<R, E, A>,
    that: Effect<R2, E2, A2>,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): Effect<R | R2, E | E2, A2>
}

Added in v1.0.0

zipWith

Signature

export declare const zipWith: {
  <R2, E2, A2, A, B>(
    that: Effect<R2, E2, A2>,
    f: (a: A, b: A2) => B,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): <R, E>(self: Effect<R, E, A>) => Effect<R2 | R, E2 | E, B>
  <R, E, A, R2, E2, A2, B>(
    self: Effect<R, E, A>,
    that: Effect<R2, E2, A2>,
    f: (a: A, b: A2) => B,
    options?: { readonly concurrent?: boolean; readonly batching?: boolean | 'inherit' }
  ): Effect<R | R2, E | E2, B>
}

Added in v1.0.0