<A1, E, E1, R1, A2, E2, R2>(
policy: Schedule<A1, NoInfer<E>, E1, R1>,
orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>
): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>
<A, E, R, A1, E1, R1, A2, E2, R2>(
self: Effect<A, E, R>,
policy: Schedule<A1, NoInfer<E>, E1, R1>,
orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>
): Effect<A | A2, E1 | E2, R | R1 | R2>Retries a failing effect and runs a fallback effect if retries are exhausted.
When to use
Use when you want to handle failures gracefully by specifying an alternative action after repeated failures.
Details
The Effect.retryOrElse function attempts to retry a failing effect multiple
times according to a defined Schedule policy.
If the retries are exhausted and the effect still fails, it runs a fallback effect instead.
Example (Falling back after retries are exhausted)
import { Console, Data, Effect, Schedule } from "effect"
class NetworkTimeoutError extends Data.TaggedError("NetworkTimeoutError")<{}> {}
let attempt = 0
const networkRequest = Effect.gen(function*() {
attempt++
yield* Console.log(`Network attempt ${attempt}`)
if (attempt < 3) {
return yield* Effect.fail(new NetworkTimeoutError())
}
return "Network data"
})
// Retry up to 2 times, then fall back to cached data
const program = Effect.retryOrElse(
networkRequest,
Schedule.recurs(2),
(error, retryCount) =>
Effect.gen(function*() {
yield* Console.log(`All ${retryCount} retries failed, using cache`)
return "Cached data"
})
)
Effect.runPromise(program).then(console.log)
// Output:
// Network attempt 1
// Network attempt 2
// Network attempt 3
// Network dataexport const const retryOrElse: {
<A1, E, E1, R1, A2, E2, R2>(
policy: Schedule<A1, NoInfer<E>, E1, R1>,
orElse: (
e: NoInfer<E>,
out: A1
) => Effect<A2, E2, R2>
): <A, R>(
self: Effect<A, E, R>
) => Effect<A | A2, E1 | E2, R | R1 | R2>
<A, E, R, A1, E1, R1, A2, E2, R2>(
self: Effect<A, E, R>,
policy: Schedule<A1, NoInfer<E>, E1, R1>,
orElse: (
e: NoInfer<E>,
out: A1
) => Effect<A2, E2, R2>
): Effect<A | A2, E1 | E2, R | R1 | R2>
}
Retries a failing effect and runs a fallback effect if retries are exhausted.
When to use
Use when you want to handle failures gracefully by specifying an alternative
action after repeated failures.
Details
The Effect.retryOrElse function attempts to retry a failing effect multiple
times according to a defined
Schedule
policy.
If the retries are exhausted and the effect still fails, it runs a fallback
effect instead.
Example (Falling back after retries are exhausted)
import { Console, Data, Effect, Schedule } from "effect"
class NetworkTimeoutError extends Data.TaggedError("NetworkTimeoutError")<{}> {}
let attempt = 0
const networkRequest = Effect.gen(function*() {
attempt++
yield* Console.log(`Network attempt ${attempt}`)
if (attempt < 3) {
return yield* Effect.fail(new NetworkTimeoutError())
}
return "Network data"
})
// Retry up to 2 times, then fall back to cached data
const program = Effect.retryOrElse(
networkRequest,
Schedule.recurs(2),
(error, retryCount) =>
Effect.gen(function*() {
yield* Console.log(`All ${retryCount} retries failed, using cache`)
return "Cached data"
})
)
Effect.runPromise(program).then(console.log)
// Output:
// Network attempt 1
// Network attempt 2
// Network attempt 3
// Network data
retryOrElse: {
<function (type parameter) A1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>A1, function (type parameter) E in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E, function (type parameter) E1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E1, function (type parameter) R1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>R1, function (type parameter) A2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>A2, function (type parameter) E2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E2, function (type parameter) R2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>R2>(
policy: Schedule<A1, NoInfer<E>, E1, R1>(parameter) policy: {
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 Schedule<out Output, in Input = unknown, out Error = never, out Env = never>A Schedule defines a strategy for repeating or retrying effects based on some policy.
Example (Defining retry and repeat schedules)
import { Console, Data, Effect, Schedule } from "effect"
class NetworkError extends Data.TaggedError("NetworkError")<{
readonly attempt: number
}> {}
// Basic retry schedule - retry up to 3 times with exponential backoff
const retrySchedule = Schedule.max([
Schedule.exponential("100 millis"),
Schedule.recurs(3)
])
// Basic repeat schedule - repeat every 30 seconds forever
const repeatSchedule: Schedule.Schedule<number, unknown, never> = Schedule
.spaced("30 seconds")
const program = Effect.gen(function*() {
let attempts = 0
const result1 = yield* Effect.retry(
Effect.gen(function*() {
attempts++
if (attempts < 3) {
return yield* Effect.fail(new NetworkError({ attempt: attempts }))
}
return "Success"
}),
retrySchedule
)
console.log(result1) // "Success"
yield* Console.log("heartbeat").pipe(
Effect.repeat(repeatSchedule.pipe(Schedule.upTo({ times: 5 })))
)
})
The Schedule namespace contains types and utilities for working with schedules.
Schedule<function (type parameter) A1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>A1, 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 <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E>, function (type parameter) E1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E1, function (type parameter) R1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>R1>,
orElse: (
e: NoInfer<E>,
out: A1
) => Effect<A2, E2, R2>
e: NoInfer<E>e: 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 <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E>, out: A1out: function (type parameter) A1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>A1) => 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 <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>A2, function (type parameter) E2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E2, function (type parameter) R2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>R2>
): <function (type parameter) A in <A, R>(self: Effect<A, E, R>): Effect<A | A2, E1 | E2, R | R1 | R2>A, function (type parameter) R in <A, R>(self: Effect<A, E, R>): Effect<A | A2, E1 | E2, R | R1 | R2>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, R>(self: Effect<A, E, R>): Effect<A | A2, E1 | E2, R | R1 | R2>A, function (type parameter) E in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E, function (type parameter) R in <A, R>(self: Effect<A, E, R>): Effect<A | A2, E1 | E2, R | R1 | R2>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, R>(self: Effect<A, E, R>): Effect<A | A2, E1 | E2, R | R1 | R2>A | function (type parameter) A2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>A2, function (type parameter) E1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E1 | function (type parameter) E2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>E2, function (type parameter) R in <A, R>(self: Effect<A, E, R>): Effect<A | A2, E1 | E2, R | R1 | R2>R | function (type parameter) R1 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>R1 | function (type parameter) R2 in <A1, E, E1, R1, A2, E2, R2>(policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | A2, E1 | E2, R | R1 | R2>R2>
<function (type parameter) A in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A, function (type parameter) E in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E, function (type parameter) R in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R, function (type parameter) A1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A1, function (type parameter) E1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E1, function (type parameter) R1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R1, function (type parameter) A2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A2, function (type parameter) E2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E2, function (type parameter) R2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R2>(
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, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A, function (type parameter) E in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E, function (type parameter) R in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R>,
policy: Schedule<A1, NoInfer<E>, E1, R1>(parameter) policy: {
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 Schedule<out Output, in Input = unknown, out Error = never, out Env = never>A Schedule defines a strategy for repeating or retrying effects based on some policy.
Example (Defining retry and repeat schedules)
import { Console, Data, Effect, Schedule } from "effect"
class NetworkError extends Data.TaggedError("NetworkError")<{
readonly attempt: number
}> {}
// Basic retry schedule - retry up to 3 times with exponential backoff
const retrySchedule = Schedule.max([
Schedule.exponential("100 millis"),
Schedule.recurs(3)
])
// Basic repeat schedule - repeat every 30 seconds forever
const repeatSchedule: Schedule.Schedule<number, unknown, never> = Schedule
.spaced("30 seconds")
const program = Effect.gen(function*() {
let attempts = 0
const result1 = yield* Effect.retry(
Effect.gen(function*() {
attempts++
if (attempts < 3) {
return yield* Effect.fail(new NetworkError({ attempt: attempts }))
}
return "Success"
}),
retrySchedule
)
console.log(result1) // "Success"
yield* Console.log("heartbeat").pipe(
Effect.repeat(repeatSchedule.pipe(Schedule.upTo({ times: 5 })))
)
})
The Schedule namespace contains types and utilities for working with schedules.
Schedule<function (type parameter) A1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A1, 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 <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E>, function (type parameter) E1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E1, function (type parameter) R1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R1>,
orElse: (
e: NoInfer<E>,
out: A1
) => Effect<A2, E2, R2>
e: NoInfer<E>e: 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 <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E>, out: A1out: function (type parameter) A1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A1) => 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, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A2, function (type parameter) E2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E2, function (type parameter) R2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R2>
): 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, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A | function (type parameter) A2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>A2, function (type parameter) E1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E1 | function (type parameter) E2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>E2, function (type parameter) R in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R | function (type parameter) R1 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R1 | function (type parameter) R2 in <A, E, R, A1, E1, R1, A2, E2, R2>(self: Effect<A, E, R>, policy: Schedule<A1, NoInfer<E>, E1, R1>, orElse: (e: NoInfer<E>, out: A1) => Effect<A2, E2, R2>): Effect<A | A2, E1 | E2, R | R1 | R2>R2>
} = import internalScheduleinternalSchedule.const retryOrElse: {
<A1, E, E1, R1, A2, E2, R2>(
policy: Schedule.Schedule<
A1,
NoInfer<E>,
E1,
R1
>,
orElse: (
e: NoInfer<E>,
out: A1
) => Effect<A2, E2, R2>
): <A, R>(
self: Effect<A, E, R>
) => Effect<A | A2, E1 | E2, R | R1 | R2>
<A, E, R, A1, E1, R1, A2, E2, R2>(
self: Effect<A, E, R>,
policy: Schedule.Schedule<
A1,
NoInfer<E>,
E1,
R1
>,
orElse: (
e: NoInfer<E>,
out: A1
) => Effect<A2, E2, R2>
): Effect<A | A2, E1 | E2, R | R1 | R2>
}