Result

An implementation of the Option Type pattern.

Returning a Result object lets you cleanly separate the return status of a function (e.g. success/fail) from the return value.

This approach is less error-prone than returning a special value (e.g. -1) to indicate failure.

let result = runProcess();
if (result.ok()) {
    print(result.get());
} else {
    die('Process failed with code: ' ~ result.failCode());
}

function runProcess() {

    // (do something that could succeed or fail)

    if (isOk) {
        return Result.new(correctData);
    }
    else {
        return Result.fail();
    }
}