mapErr

Result.mapErr transforms the contained error using the provided projection.

Result<T, E>.mapErr = <F>(op: (err: E) => F) => Result<T, F>;

Example

div(2, 0).mapErr<string>(err => {
  if (err === MathError.DivisionByZero) {
    return 'You tried to divide by zero. That doesn\'t work'
  }

  return err;
}); // Err('You tried to divide by zero. That doesn\'t work')