isErr | /src/result/mod.ts | ahh@v0.11.0

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Opinionated idiomatic type-safety functions.

function isErr

import { isErr } from "https://deno.land/x/ahh@v0.11.0/src/result/mod.ts";

isErr<T, E extends Error>(res: Result<T, E>): res is Err<E>

Returns whether res is an Err.

Examples

Example 1

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

console.log(R.isErr(1)); // false
console.log(R.isErr(Error())); // true

E extends Error

res: Result<T, E>

res is Err<E>