<E extends Cause.Done>(input: Cause.Cause<E>): Result.Result<
Cause.Done,
Cause.Cause<Exclude<E, Cause.Done>>
>Finds a Cause.Done failure in a cause whose done value is not used.
When to use
Use to detect Cause.Done completion in a Cause when the completion value
is not part of the downstream logic.
Details
Returns a successful Result with the done marker when present, otherwise
returns a failed Result with the non-done cause.
export const const filterDoneVoid: <
E extends Cause.Done
>(
input: Cause.Cause<E>
) => Result.Result<
Cause.Done,
Cause.Cause<Exclude<E, Cause.Done>>
>
Finds a Cause.Done failure in a cause whose done value is not used.
When to use
Use to detect Cause.Done completion in a Cause when the completion value
is not part of the downstream logic.
Details
Returns a successful Result with the done marker when present, otherwise
returns a failed Result with the non-done cause.
filterDoneVoid: <function (type parameter) E in <E extends Cause.Done>(input: Cause.Cause<E>): Result.Result<Cause.Done, Cause.Cause<Exclude<E, Cause.Done>>>E extends import CauseCause.type Cause.Done = /*unresolved*/ anyDone>(
input: Cause.Cause<E>(parameter) input: {
reasons: ReadonlyArray<Reason<E>>;
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 CauseCause.type Cause.Cause = /*unresolved*/ anyCause<function (type parameter) E in <E extends Cause.Done>(input: Cause.Cause<E>): Result.Result<Cause.Done, Cause.Cause<Exclude<E, Cause.Done>>>E>
) => import ResultResult.type Result<A, E = never> = Result.Success<A, E> | Result.Failure<A, E>A value that is either Success<A, E> or Failure<A, E>.
When to use
Use when both success and failure should remain available as data and
Option would lose failure information.
Details
- Use
succeed
/
fail
to construct
- Use
match
to fold both branches
- Use
isSuccess
/
isFailure
to narrow the type
E defaults to never, so Result<number> means a result that cannot fail.
Example (Creating and matching a Result)
import { Result } from "effect"
const success = Result.succeed(42)
const failure = Result.fail("something went wrong")
const message = Result.match(success, {
onSuccess: (value) => `Success: ${value}`,
onFailure: (error) => `Error: ${error}`
})
console.log(message)
// Output: "Success: 42"
Namespace containing type-level utilities for extracting the inner types
of a Result.
Example (Extracting inner types)
import type { Result } from "effect"
type R = Result.Result<number, string>
// number
type A = Result.Result.Success<R>
// string
type E = Result.Result.Failure<R>
Result<import CauseCause.type Cause.Done = /*unresolved*/ anyDone, import CauseCause.type Cause.Cause = /*unresolved*/ anyCause<type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) E in <E extends Cause.Done>(input: Cause.Cause<E>): Result.Result<Cause.Done, Cause.Cause<Exclude<E, Cause.Done>>>E, import CauseCause.type Cause.Done = /*unresolved*/ anyDone>>> = import FilterFilter.composePassthrough(
import CauseCause.findError,
(e: anye) => import CauseCause.isDone(e: anye) ? import ResultResult.const succeed: <A>(right: A) => Result<A>Creates a Result holding a Success value.
Details
- Use when you have a value and want to lift it into the
Result type
- The error type
E defaults to never
Example (Wrapping a value)
import { Result } from "effect"
const result = Result.succeed(42)
console.log(Result.isSuccess(result))
// Output: true
succeed(e: anye) : import ResultResult.const fail: <E>(
left: E
) => Result<never, E>
Creates a Result holding a Failure value.
When to use
Use to represent a failed Result with a typed failure value.
Details
- The success type
A defaults to never
Example (Creating a failure)
import { Result } from "effect"
const result = Result.fail("Something went wrong")
console.log(Result.isFailure(result))
// Output: true
fail(e: anye)
) as any