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0 pointsknocte1mo ago0 comments

Yup, in my TODO list (I've only recently published this package). For now you can just check the tests, or a SO answer I wrote a while ago (before I published the idea as an npm package): https://stackoverflow.com/a/78937127/544947

0 comments

c-hendricks1mo ago

I still struggle to see the advantage of Option<T> in a language with null-safe accessors and unions

    function fnO(val?: number) {
        if (val == null) {
            return "NAH";
        } else {
            return (val * val).toString();
        }
    }

    test("testing Options", () => {
        let foo = undefined;
        let bar = 2;
        expect(fnO(foo)).toBe("NAH");
        expect(fnO(bar)).toBe("4");
    });

Your readme states

> FP's languages approach of rather not having null at all

But `None` is just another null / undefined, which brings along a bunch of non-idiomatic code around handling it.

knocteOP17d ago

None is not just another nullish value.

If you do a type check with None, and there is some value inside (so it is Some, not None), it is IMPOSSIBLE that the .value that you extract underneath is gone. This is an important race-condition that you might run into due to the nature of TS/JS, but by boxing the value with an immutable Option type, you're protected.

Also this prevents people to run into NullReferenceException (or UndefinedRefsExceptions, or whatever is called in this ecosystem) for people that didn't turn strictNullChecks ON.

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