<R>(context: Context.Context<R>): <A, E>(
effect: Effect<A, E, R>
) => Exit.Exit<A, E>Runs an effect synchronously with provided services, returning an Exit result safely.
When to use
Use when you already have a Context and need a synchronous Exit instead of
throwing on failure.
Example (Running synchronously with services as Exit)
import { Context, Effect, Exit } from "effect"
// Define a logger service
const Logger = Context.Service<{
log: (msg: string) => void
}>("Logger")
const program = Effect.gen(function*() {
const logger = yield* Effect.service(Logger)
logger.log("Computing result...")
return 42
})
// Prepare context
const context = Context.make(Logger, {
log: (msg) => console.log(`[LOG] ${msg}`)
})
const exit = Effect.runSyncExitWith(context)(program)
if (Exit.isSuccess(exit)) {
console.log(`Success: ${exit.value}`)
} else {
console.log(`Failure: ${exit.cause}`)
}
// Output:
// [LOG] Computing result...
// Success: 42export const const runSyncExitWith: <R>(
context: Context.Context<R>
) => <A, E>(
effect: Effect<A, E, R>
) => Exit.Exit<A, E>
Runs an effect synchronously with provided services, returning an Exit result safely.
When to use
Use when you already have a Context and need a synchronous Exit instead of
throwing on failure.
Example (Running synchronously with services as Exit)
import { Context, Effect, Exit } from "effect"
// Define a logger service
const Logger = Context.Service<{
log: (msg: string) => void
}>("Logger")
const program = Effect.gen(function*() {
const logger = yield* Effect.service(Logger)
logger.log("Computing result...")
return 42
})
// Prepare context
const context = Context.make(Logger, {
log: (msg) => console.log(`[LOG] ${msg}`)
})
const exit = Effect.runSyncExitWith(context)(program)
if (Exit.isSuccess(exit)) {
console.log(`Success: ${exit.value}`)
} else {
console.log(`Failure: ${exit.cause}`)
}
// Output:
// [LOG] Computing result...
// Success: 42
runSyncExitWith: <function (type parameter) R in <R>(context: Context.Context<R>): <A, E>(effect: Effect<A, E, R>) => Exit.Exit<A, E>R>(
context: Context.Context<R>(parameter) context: {
mapUnsafe: ReadonlyMap<string, any>;
mutable: boolean;
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 ContextContext.type Context.Context = /*unresolved*/ anyContext<function (type parameter) R in <R>(context: Context.Context<R>): <A, E>(effect: Effect<A, E, R>) => Exit.Exit<A, E>R>
) => <function (type parameter) A in <A, E>(effect: Effect<A, E, R>): Exit.Exit<A, E>A, function (type parameter) E in <A, E>(effect: Effect<A, E, R>): Exit.Exit<A, E>E>(effect: Effect<A, E, R>(parameter) effect: {
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>(effect: Effect<A, E, R>): Exit.Exit<A, E>A, function (type parameter) E in <A, E>(effect: Effect<A, E, R>): Exit.Exit<A, E>E, function (type parameter) R in <R>(context: Context.Context<R>): <A, E>(effect: Effect<A, E, R>) => Exit.Exit<A, E>R>) => import ExitExit.type Exit<A, E = never> = Exit.Success<A, E> | Exit.Failure<A, E>Represents the result of an Effect computation.
When to use
Use when you need to synchronously inspect whether an Effect computation
succeeded or failed.
Details
An Exit<A, E> is either Success<A, E> containing a value of type A, or
Failure<A, E> containing a Cause<E> describing why the computation
failed.
Since Exit is also an Effect, you can yield it inside Effect.gen.
Example (Pattern matching on an Exit)
import { Exit } from "effect"
const success: Exit.Exit<number> = Exit.succeed(42)
const failure: Exit.Exit<number, string> = Exit.fail("error")
const result = Exit.match(success, {
onSuccess: (value) => `Got value: ${value}`,
onFailure: (cause) => `Got error: ${cause}`
})
Namespace containing helper types shared by Exit values.
When to use
Use to reference helper types that describe the shared structure of Exit
values.
Exit<function (type parameter) A in <A, E>(effect: Effect<A, E, R>): Exit.Exit<A, E>A, function (type parameter) E in <A, E>(effect: Effect<A, E, R>): Exit.Exit<A, E>E> = import internalinternal.const runSyncExitWith: <R>(
context: Context.Context<R>
) => <A, E>(
effect: Effect.Effect<A, E, R>
) => Exit.Exit<A, E>