effect-io-ai

Package: effect
Module: Result

Result.fromOption

Converts an Option<A> into a Result<A, E>.

When to use

Use when an existing Option should become a Result, preserving Some as success and turning None into a caller-provided failure.

Details

• Some<A> becomes Success<A>
• None becomes Failure<E> using the provided function
• Supports both data-first and data-last (piped) usage

Example (Converting an Option to a Result)

import { Option, Result } from "effect"

const some = Result.fromOption(Option.some(1), () => "missing")
console.log(some)
// Output: { _tag: "Success", success: 1, ... }

const none = Result.fromOption(Option.none(), () => "missing")
console.log(none)
// Output: { _tag: "Failure", failure: "missing", ... }

See

• getSuccess to extract the success value as an Option
• getFailure to extract the failure value as an Option
• fromNullishOr to build a Result from nullable values

Signature

declare const fromOption: { <E>(onNone: () => E): <A>(self: Option<A>) => Result<A, E>; <A, E>(self: Option<A>, onNone: () => E): Result<A, E>; }

Source

Since v2.0.0