<A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>Maps the success value of an Effect to Some, preserving failures.
Example (Wrapping success in Option.some)
import { Effect } from "effect"
const program = Effect.asSome(Effect.succeed(42))
Effect.runPromise(program).then(console.log)
// { _id: 'Option', _tag: 'Some', value: 42 }export const const asSome: <A, E, R>(
self: Effect<A, E, R>
) => Effect<Option<A>, E, R>
Maps the success value of an Effect to Some, preserving failures.
Example (Wrapping success in Option.some)
import { Effect } from "effect"
const program = Effect.asSome(Effect.succeed(42))
Effect.runPromise(program).then(console.log)
// { _id: 'Option', _tag: 'Some', value: 42 }
asSome: <function (type parameter) A in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, 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<Option<A>, E, R>A, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, 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<type Option<A> = None<A> | Some<A>The Option data type represents optional values. An Option<A> is either
Some<A>, containing a value of type A, or None, representing absence.
When to use
Use to represent initial values that may not yet exist
- Returning from partial functions (not defined for all inputs)
- Managing optional fields in data structures
Namespace containing utility types for Option.
When to use
Use to access type-level helpers associated with Option.
Option<function (type parameter) A in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>A>, function (type parameter) E in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>E, function (type parameter) R in <A, E, R>(self: Effect<A, E, R>): Effect<Option<A>, E, R>R> = import internalinternal.const asSome: <A, E, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<Option.Option<A>, E, R>