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Module

x/fun/promise.ts>map

A collection of algebraic data types, lenses, and schemables based on a light weight higher kinded type implementation. Written for deno.
baetheus/fun
Latest
function map
import { map } from "https://deno.land/x/fun@v2.0.0/promise.ts";

Create a new Promise by mapping over the result of an existing Promise. This is effectively Promise.then, but narrowed to non-promise returning functions. If the mapping function returns a Promise then the type for this function will be incorrect, as there is no way to create a Promise<Promise>.

Examples

Example 1

import { wrap, map } from "./promise.ts";
import { pipe } from "./fn.ts";

const result = await pipe(
  wrap(1),
  map(n => n + 1),
); // 2

Parameters

fai: (a: A) => I

Returns

(ua: Promise<A>) => Promise<I>