<E, A2, E2, R2>(
f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>
): <A, In, L, R>(
self: Sink<A, In, L, E, R>
) => Sink<A2 | A, In, L, E, R2 | R>
<A, In, L, E, R, A2, E2, R2>(
self: Sink<A, In, L, E, R>,
f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>
): Sink<A | A2, In, L, E2, R | R2>Handles failures from this sink by inspecting the full Cause.
When to use
Use to recover from a sink failure based on the full Cause instead of only
the typed error value.
Details
When this sink fails, the handler effect is run and its success value becomes the sink result. If the handler fails, the returned sink fails with that error.
export const const catchCause: {
<E, A2, E2, R2>(
f: (
error: Cause.Cause<Types.NoInfer<E>>
) => Effect.Effect<A2, E2, R2>
): <A, In, L, R>(
self: Sink<A, In, L, E, R>
) => Sink<A2 | A, In, L, E, R2 | R>
<A, In, L, E, R, A2, E2, R2>(
self: Sink<A, In, L, E, R>,
f: (
error: Cause.Cause<E>
) => Effect.Effect<A2, E2, R2>
): Sink<A | A2, In, L, E2, R | R2>
}
Handles failures from this sink by inspecting the full Cause.
When to use
Use to recover from a sink failure based on the full Cause instead of only
the typed error value.
Details
When this sink fails, the handler effect is run and its success value
becomes the sink result. If the handler fails, the returned sink fails with
that error.
catchCause: {
<function (type parameter) E in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>E, function (type parameter) A2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>A2, function (type parameter) E2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>E2, function (type parameter) R2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>R2>(
f: (
error: Cause.Cause<Types.NoInfer<E>>
) => Effect.Effect<A2, E2, R2>
error: Cause.Cause<Types.NoInfer<E>>(parameter) error: {
reasons: ReadonlyArray<Reason<E>>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import CauseCause.interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<import TypesTypes.type NoInfer<A> = [A][A extends any
? 0
: never]
Prevents TypeScript from inferring a type parameter from a specific
position.
When to use
Use when a function parameter must match an inferred type without becoming
an inference source.
Details
The parameter using NoInfer must still match the inferred type.
Example (Controlling inference)
import type { Types } from "effect"
declare function withDefault<T>(value: T, fallback: Types.NoInfer<T>): T
// T is inferred as "a" | "b" from the first argument only
const result = withDefault<"a" | "b">("a", "b")
NoInfer<function (type parameter) E in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>E>>) => import EffectEffect.interface Effect<out A, out E = never, out R = never>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.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
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.
Effect<function (type parameter) A2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>A2, function (type parameter) E2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>E2, function (type parameter) R2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>R2>
): <function (type parameter) A in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>A, function (type parameter) In in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>In, function (type parameter) L in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>L, function (type parameter) R in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>R>(self: Sink<A, In, L, E, R>(parameter) self: {
transform: (upstream: Pull.Pull<NonEmptyReadonlyArray<In>, never, void>, scope: Scope.Scope) => Effect.Effect<End<A, L>, E, R>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) A in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>A, function (type parameter) In in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>In, function (type parameter) L in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>L, function (type parameter) E in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>E, function (type parameter) R in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>R>) => interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) A2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>A2 | function (type parameter) A in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>A, function (type parameter) In in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>In, function (type parameter) L in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>L, function (type parameter) E in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>E, function (type parameter) R2 in <E, A2, E2, R2>(f: (error: Cause.Cause<Types.NoInfer<E>>) => Effect.Effect<A2, E2, R2>): <A, In, L, R>(self: Sink<A, In, L, E, R>) => Sink<A2 | A, In, L, E, R2 | R>R2 | function (type parameter) R in <A, In, L, R>(self: Sink<A, In, L, E, R>): Sink<A2 | A, In, L, E, R2 | R>R>
<function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A, function (type parameter) In in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>In, function (type parameter) L in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>L, function (type parameter) E in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E, function (type parameter) R in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R, function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2, function (type parameter) E2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E2, function (type parameter) R2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R2>(
self: Sink<A, In, L, E, R>(parameter) self: {
transform: (upstream: Pull.Pull<NonEmptyReadonlyArray<In>, never, void>, scope: Scope.Scope) => Effect.Effect<End<A, L>, E, R>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A, function (type parameter) In in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>In, function (type parameter) L in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>L, function (type parameter) E in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E, function (type parameter) R in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R>,
f: (
error: Cause.Cause<E>
) => Effect.Effect<A2, E2, R2>
error: Cause.Cause<E>(parameter) error: {
reasons: ReadonlyArray<Reason<E>>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import CauseCause.interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<function (type parameter) E in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E>) => import EffectEffect.interface Effect<out A, out E = never, out R = never>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.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
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.
Effect<function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2, function (type parameter) E2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E2, function (type parameter) R2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R2>
): interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A | function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2, function (type parameter) In in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>In, function (type parameter) L in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>L, function (type parameter) E2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E2, function (type parameter) R in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R | function (type parameter) R2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R2>
} = dual<(...args: Array<any>) => any, <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>) => Sink<A | A2, In, L, E2, R | R2>>(arity: 2, body: <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>) => Sink<A | A2, In, L, E2, R | R2>): ((...args: Array<any>) => any) & (<A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>) => Sink<A | A2, In, L, E2, R | R2>) (+1 overload)Creates a function that can be called in data-first style or data-last
(pipe-friendly) style.
When to use
Use to expose one implementation through both direct and pipe-friendly
call styles.
Details
Pass either the arity of the uncurried function or a predicate that decides
whether the current call is data-first. Arity is the common case. Use a
predicate when optional arguments make arity ambiguous.
Example (Selecting data-first or data-last style by arity)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(2, (self, that) => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Defining overloads with call signatures)
import { Function, pipe } from "effect"
const sum: {
(that: number): (self: number) => number
(self: number, that: number): number
} = Function.dual(2, (self: number, that: number): number => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Selecting data-first or data-last style with a predicate)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(
(args) => args.length === 2,
(self, that) => self + that
)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
dual(2, <function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A, function (type parameter) In in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>In, function (type parameter) L in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>L, function (type parameter) E in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E, function (type parameter) R in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R, function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2, function (type parameter) E2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E2, function (type parameter) R2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R2>(
self: Sink<A, In, L, E, R>(parameter) self: {
transform: (upstream: Pull.Pull<NonEmptyReadonlyArray<In>, never, void>, scope: Scope.Scope) => Effect.Effect<End<A, L>, E, R>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A, function (type parameter) In in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>In, function (type parameter) L in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>L, function (type parameter) E in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E, function (type parameter) R in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R>,
f: (
error: Cause.Cause<E>
) => Effect.Effect<A2, E2, R2>
error: Cause.Cause<E>(parameter) error: {
reasons: ReadonlyArray<Reason<E>>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import CauseCause.interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<function (type parameter) E in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E>) => import EffectEffect.interface Effect<out A, out E = never, out R = never>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.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
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.
Effect<function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2, function (type parameter) E2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E2, function (type parameter) R2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R2>
): interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A | function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2, function (type parameter) In in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>In, function (type parameter) L in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>L, function (type parameter) E2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>E2, function (type parameter) R in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R | function (type parameter) R2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>R2> =>
const transformEffect: <
A,
In,
L,
E,
R,
A2,
E2,
R2,
L2 = never
>(
self: Sink<A, In, L, E, R>,
f: (
effect: Effect.Effect<End<A, L>, E, R>
) => Effect.Effect<End<A2, L2>, E2, R2>
) => Sink<A2, In, L2, E2, R2>
self: Sink<A, In, L, E, R>(parameter) self: {
transform: (upstream: Pull.Pull<NonEmptyReadonlyArray<In>, never, void>, scope: Scope.Scope) => Effect.Effect<End<A, L>, E, R>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
import EffectEffect.const catchCause: {
<E, A2, E2, R2>(
f: (
cause: Cause.Cause<E>
) => Effect<A2, E2, R2>
): <A, R>(
self: Effect<A, E, R>
) => Effect<A2 | A, E2, R2 | R>
<A, E, R, A2, E2, R2>(
self: Effect<A, E, R>,
f: (
cause: Cause.Cause<E>
) => Effect<A2, E2, R2>
): Effect<A | A2, E2, R | R2>
}
cause: Cause.Cause<E>(parameter) cause: {
reasons: ReadonlyArray<Reason<E>>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import EffectEffect.const map: {
<A, B>(f: (a: A) => B): <E, R>(
self: Effect<A, E, R>
) => Effect<B, E, R>
<A, E, R, B>(
self: Effect<A, E, R>,
f: (a: A) => B
): Effect<B, E, R>
}
f: (
error: Cause.Cause<E>
) => Effect.Effect<A2, E2, R2>
cause: Cause.Cause<E>(parameter) cause: {
reasons: ReadonlyArray<Reason<E>>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
a2: A2a2) => [a2: A2a2 as function (type parameter) A in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A | function (type parameter) A2 in <A, In, L, E, R, A2, E2, R2>(self: Sink<A, In, L, E, R>, f: (error: Cause.Cause<E>) => Effect.Effect<A2, E2, R2>): Sink<A | A2, In, L, E2, R | R2>A2] as type const = readonly [A | A2]const))
))