effect-io-ai

Package: effect
Module: Option

Option.match

Performs pattern matching on an Option to handle both Some and None cases.

Details

This function allows you to match against an Option and handle both scenarios: when the Option is None (i.e., contains no value), and when the Option is Some (i.e., contains a value). It executes one of the provided functions based on the case:

• If the Option is None, the onNone function is executed and its result is returned.
• If the Option is Some, the onSome function is executed with the contained value, and its result is returned.

This function provides a concise and functional way to handle optional values without resorting to if or manual checks, making your code more declarative and readable.

Example (Pattern Matching with Option)

import { Option } from "effect"

const foo = Option.some(1)

const message = Option.match(foo, {
  onNone: () => "Option is empty",
  onSome: (value) => `Option has a value: ${value}`
})

console.log(message)
// Output: "Option has a value: 1"

Signature

declare const match: { <B, A, C = B>(options: { readonly onNone: LazyArg<B>; readonly onSome: (a: A) => C; }): (self: Option<A>) => B | C; <A, B, C = B>(self: Option<A>, options: { readonly onNone: LazyArg<B>; readonly onSome: (a: A) => C; }): B | C; }

Source

Since v2.0.0