R | /mod.ts | ahh@v0.10.1

Idiomatic type-safety functions.

method R.mapErr

import { R } from "https://deno.land/x/ahh@v0.10.1/mod.ts";

mapErr<T, E extends Error, F extends Error>(res: Result<T, E>, f: (_: E) => F): Result<T, F>

Calls f with res, and returns the result.

Examples

import { R } from "./mod.ts";

console.log(R.map(1, (_) => Error("new"))); // 1
console.log(R.map(Error(), (_) => Error("new"))); // Error("new")

E extends Error

F extends Error

res: Result<T, E>

f: (_: E) => F