<A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<
Option<A>,
E,
R
>Converts an Option of an Effect into an Effect of an Option.
When to use
Use when an effect should run only when an optional value is present, while
preserving absence as a successful None.
Details
Nonebecomes an effect that succeeds withNoneSome(effect)runs the inner effect and wraps its success value inSome- Inner failures are preserved in the resulting effect
Example (Transposing an Option of an Effect)
import { Effect, Option } from "effect"
const some = Option.some(Effect.succeed(42))
// ┌─── Effect<Option<number>, never, never>
// ▼
const program = Effect.transposeOption(some)
Effect.runPromise(program).then(console.log)
// Output: { _id: 'Option', _tag: 'Some', value: 42 }export const const transposeOption: <
A = never,
E = never,
R = never
>(
self: Option<Effect<A, E, R>>
) => Effect<Option<A>, E, R>
Converts an Option of an Effect into an Effect of an Option.
When to use
Use when an effect should run only when an optional value is present, while
preserving absence as a successful None.
Details
None becomes an effect that succeeds with NoneSome(effect) runs the inner effect and wraps its success value in Some- Inner failures are preserved in the resulting effect
Example (Transposing an Option of an Effect)
import { Effect, Option } from "effect"
const some = Option.some(Effect.succeed(42))
// ┌─── Effect<Option<number>, never, never>
// ▼
const program = Effect.transposeOption(some)
Effect.runPromise(program).then(console.log)
// Output: { _id: 'Option', _tag: 'Some', value: 42 }
transposeOption: <function (type parameter) A in <A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>A = never, function (type parameter) E in <A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>E = never, function (type parameter) R in <A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>R = never>(
self: Option<Effect<A, E, R>>self: 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<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 = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>A, function (type parameter) E in <A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>E, function (type parameter) R in <A = never, E = never, R = never>(self: Option<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 = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>A>, function (type parameter) E in <A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>E, function (type parameter) R in <A = never, E = never, R = never>(self: Option<Effect<A, E, R>>): Effect<Option<A>, E, R>R> = import internalinternal.const transposeOption: <
A = never,
E = never,
R = never
>(
self: Option.Option<Effect.Effect<A, E, R>>
) => Effect.Effect<Option.Option<A>, E, R>