effect-io-ai

Package: effect
Module: Option

Option.getEquivalence

Creates an Equivalence instance for comparing Option values, using a provided Equivalence for the inner type.

Details

This function takes an Equivalence instance for a specific type A and produces an Equivalence instance for Option<A>. The resulting Equivalence determines whether two Option values are equivalent:

• Two Nones are considered equivalent.
• A Some and a None are not equivalent.
• Two Some values are equivalent if their inner values are equivalent according to the provided Equivalence.

Example (Comparing Optional Numbers for Equivalence)

import { Number, Option } from "effect"

const isEquivalent = Option.getEquivalence(Number.Equivalence)

console.log(isEquivalent(Option.none(), Option.none()))
// Output: true

console.log(isEquivalent(Option.none(), Option.some(1)))
// Output: false

console.log(isEquivalent(Option.some(1), Option.none()))
// Output: false

console.log(isEquivalent(Option.some(1), Option.some(2)))
// Output: false

console.log(isEquivalent(Option.some(1), Option.some(1)))
// Output: true

Signature

declare const getEquivalence: <A>(isEquivalent: Equivalence.Equivalence<A>) => Equivalence.Equivalence<Option<A>>

Source

Since v2.0.0