<A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>Runs an effect with a scope that closes when the effect completes.
When to use
Use to acquire scoped resources for the duration of a single workflow.
Details
Finalizers for resources acquired inside the workflow run as soon as the workflow completes, whether by success, failure, or interruption.
Example (Running a scoped acquisition)
import { Console, Effect } from "effect"
const resource = Effect.acquireRelease(
Console.log("Acquiring resource").pipe(Effect.as("resource")),
() => Console.log("Releasing resource")
)
const program = Effect.scoped(
Effect.gen(function*() {
const res = yield* resource
yield* Console.log(`Using ${res}`)
return res
})
)
Effect.runFork(program)
// Output: "Acquiring resource"
// Output: "Using resource"
// Output: "Releasing resource"export const const scoped: <A, E, R>(
self: Effect<A, E, R>
) => Effect<A, E, Exclude<R, Scope>>
Runs an effect with a scope that closes when the effect completes.
When to use
Use to acquire scoped resources for the duration of a single workflow.
Details
Finalizers for resources acquired inside the workflow run as soon as the
workflow completes, whether by success, failure, or interruption.
Example (Running a scoped acquisition)
import { Console, Effect } from "effect"
const resource = Effect.acquireRelease(
Console.log("Acquiring resource").pipe(Effect.as("resource")),
() => Console.log("Releasing resource")
)
const program = Effect.scoped(
Effect.gen(function*() {
const res = yield* resource
yield* Console.log(`Using ${res}`)
return res
})
)
Effect.runFork(program)
// Output: "Acquiring resource"
// Output: "Using resource"
// Output: "Releasing resource"
scoped: <function (type parameter) A in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>R>(
self: Effect<A, E, R>(parameter) self: {
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;
}
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) A in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>R>
) => 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) A in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>E, type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<A, E, Exclude<R, Scope>>R, Scope>> = import internalinternal.const scoped: <A, E, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<A, E, Exclude<R, Scope.Scope>>