mapOr | /mod.ts | optio@1.0.0

function mapOr

import { mapOr } from "https://deno.land/x/optio@1.0.0/mod.ts";

mapOr<T, U>(

option: Option<T>,

defaultValue: U,

fn: (value: T) => U,

): U

Returns the provided default value (if None), or applies a function to the contained value (if Some).

Examples

Example 1

import { mapOr, Option, Some } from "https://deno.land/x/optio/mod.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

const option: Option<string> = Some("Hello");
assertEquals(mapOr(option, 0, ({ length }) => length), 5);

Type Parameters

Parameters

option: Option<T>

defaultValue: U

fn: (value: T) => U