effect-io-ai

Package: effect
Module: Option

Option.map

Transforms the value inside a Some using the provided function, leaving None unchanged.

When to use

Use to apply a pure transformation to an Option’s present value, especially when chaining transformations in a pipeline.

Details

• Some → applies f and wraps the result in a new Some
• None → returns None unchanged

Example (Mapping over an Option)

import { Option } from "effect"

console.log(Option.map(Option.some(2), (n) => n * 2))
// Output: { _id: 'Option', _tag: 'Some', value: 4 }

console.log(Option.map(Option.none(), (n: number) => n * 2))
// Output: { _id: 'Option', _tag: 'None' }

See

• flatMap when f returns an Option
• as to replace the value with a constant

Signature

declare const map: { <A, B>(f: (a: A) => B): (self: Option<A>) => Option<B>; <A, B>(self: Option<A>, f: (a: A) => B): Option<B>; }

Source

Since v2.0.0