effect-io-ai

Package: effect
Module: Option

Option.getOrElse

Extracts the value from a Some, or evaluates a fallback thunk on None.

When to use

Use when providing a default value for an absent Option

• Unwrapping with lazy evaluation of the fallback

Details

• Some → returns the inner value
• None → calls onNone() and returns its result
• onNone is only called when needed (lazy)

Example (Unwrapping with a fallback)

import { Option } from "effect"

console.log(Option.some(1).pipe(Option.getOrElse(() => 0)))
// Output: 1

console.log(Option.none().pipe(Option.getOrElse(() => 0)))
// Output: 0

See

• getOrNull to fall back to null
• getOrUndefined to fall back to undefined
• getOrThrow to throw on None

Signature

declare const getOrElse: { <B>(onNone: LazyArg<B>): <A>(self: Option<A>) => B | A; <A, B>(self: Option<A>, onNone: LazyArg<B>): A | B; }

Source

Since v2.0.0