map

function Result.map(
    result: Result<T, E>,
    transform: (value: T) => U
): Result<U, E>

Transforms the value inside an Ok result using the transform function. If the result is an Err, it returns the Err unchanged.

Example

data-first

Result.map(ok(5), (x) => x * 2);
// Ok<number>

Result.map(err("fail"), (x) => x * 2);
// Err<string>

data-last

pipe(
    ok(5),
    Result.map((x) => x * 2),
);
// Ok<number>