effect-io-ai

Package: effect
Module: Option

Option.andThen

Chains a second computation onto an Option. The second value can be a plain value, an Option, or a function returning either.

When to use

Use when you need to chain an Option with a next step that may be another Option, a plain value, or a function.

Details

• If self is None, returns None immediately
• If f is a function, calls it with the Some value
• If f returns an Option, returns it as-is; if a plain value, wraps in Some
• If f is not a function, uses it directly (same wrapping rules)

Example (Chaining with andThen)

import { Option } from "effect"

// Chain with a function returning Option
console.log(Option.andThen(Option.some(5), (x) => Option.some(x * 2)))
// Output: { _id: 'Option', _tag: 'Some', value: 10 }

// Chain with a static value
console.log(Option.andThen(Option.some(5), "hello"))
// Output: { _id: 'Option', _tag: 'Some', value: "hello" }

// Chain with None - skips
console.log(Option.andThen(Option.none(), (x) => Option.some(x * 2)))
// Output: { _id: 'Option', _tag: 'None' }

See

• flatMap for the standard monadic bind
• map when you always return a plain value

Signature

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

Source

Since v2.0.0