mapSecond
import { mapSecond } from "https://github.gh-proxy.cn/raw.githubusercontent.com/baetheus/fun/main/either.ts";Apply a function to the Left value of an Either. Right values are unchanged.
@example
import * as E from "./either.ts";
const result1 = E.mapSecond((error: string) => `Error: ${error}`)(E.left("failed"));
// Left("Error: failed")
const result2 = E.mapSecond((error: string) => `Error: ${error}`)(E.right(42));
// Right(42)