<B>(value: B): <A, E, R>(self: Effect<A, E, R>) => Effect<B, E, R>
<A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>Replaces the value inside an effect with a constant value.
When to use
Use to replace a successful value with a constant while preserving failures and requirements.
Details
as allows you to ignore the original value inside an effect and
replace it with a new constant value.
Example (Replacing a success value)
import { Effect, pipe } from "effect"
// Replaces the value 5 with the constant "new value"
const program = pipe(Effect.succeed(5), Effect.as("new value"))
Effect.runPromise(program).then(console.log)
// Output: "new value"export const const as: {
<B>(value: B): <A, E, R>(
self: Effect<A, E, R>
) => Effect<B, E, R>
<A, E, R, B>(
self: Effect<A, E, R>,
value: B
): Effect<B, E, R>
}
Replaces the value inside an effect with a constant value.
When to use
Use to replace a successful value with a constant while preserving failures
and requirements.
Details
as allows you to ignore the original value inside an effect and
replace it with a new constant value.
Example (Replacing a success value)
import { Effect, pipe } from "effect"
// Replaces the value 5 with the constant "new value"
const program = pipe(Effect.succeed(5), Effect.as("new value"))
Effect.runPromise(program).then(console.log)
// Output: "new value"
as: {
<function (type parameter) B in <B>(value: B): <A, E, R>(self: Effect<A, E, R>) => Effect<B, E, R>B>(value: Bvalue: function (type parameter) B in <B>(value: B): <A, E, R>(self: Effect<A, E, R>) => Effect<B, E, R>B): <function (type parameter) A in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>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<B, E, R>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>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) B in <B>(value: B): <A, E, R>(self: Effect<A, E, R>) => Effect<B, E, R>B, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<B, E, R>R>
<function (type parameter) A in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>A, function (type parameter) E in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>R, function (type parameter) B in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>B>(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, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>A, function (type parameter) E in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>R>, value: Bvalue: function (type parameter) B in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>B): 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) B in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>B, function (type parameter) E in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Effect<A, E, R>, value: B): Effect<B, E, R>R>
} = import internalinternal.const as: {
<A, B>(value: B): <E, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<B, E, R>
<A, E, R, B>(
self: Effect.Effect<A, E, R>,
value: B
): Effect.Effect<B, E, R>
}