Function isErr

isErr<T, E>(result: Result<T, E>): result is Err<E>

Used to check if a result is an Err.

Type Parameters

T
E

Parameters

result: Result<T, E>

Returns result is Err<E>

Example

const result: Result<number, string> = err("error");
const isErrResult: boolean = isErr(result); // true

Example

if (isErr(result)) {
	// We now know that the result is an Err
 // so we can safely use it
	const error: string = unwrapErr(result); // "error"
}