Porffor: A from-scratch experimental ahead-of-time JS engine

Post by stabbles » Wed, Jul 31, 2024, 9:36 PM UTC

pandemic_region wrote: post #77

pityJuke wrote: post #36

Earlier quoted context omitted.

Also funded the Ladybird browser recently. Seems to like his web.

Not familiar with this stuff at all, is Porffor a js engine that Ladybird could end up using? Or are they still writing their own?

Post by noway421 » Wed, Jul 31, 2024, 10:05 PM UTC

sixbrx wrote: post #49

wk_end wrote: post #32

Earlier quoted context omitted.

So - I know this in theory, but avoided mentioning it because I couldn’t immediately think of any persuasive examples (whereas subtype polymorphism is a core, widely used, wholly unrestricted property of the language) that didn’t involve casts or any/unknown or other things that people might make excuses for. Do you have any examples off the top of your head?

Here's an example I constructed after reading the TS docs [1] about flow-based type inference and thinking "that can't be right...". It yields no warnings or errors at compile stage but gives runtime error based on a wrong flow-based type inference. The crux of it is that something can be a Bird (with "fly" function) but can also have any other members, like "swim" because of structural typing (flying is the minimum…

    type Bird = { id: number };
    type Human = { swim?: () => void; id: number };

    function move(animal: Bird | Human) {
        onlyForHumans(animal); 
    }

    function onlyForHumans(swimmer: Human) {
      if (swimmer.swim) {
        swimmer.swim();
      }
    }

    const someObj = { id: 1, swim: "not-callable" };
    move(someObj);

Post by fyrn_ » Thu, Aug 01, 2024, 12:22 AM UTC

giancarlostoro wrote: post #99

pandemic_region wrote: post #77

Earlier quoted context omitted.

Not familiar with this stuff at all, is Porffor a js engine that Ladybird could end up using? Or are they still writing their own?

Porffor compiles the JS to WASM, so it would be kind of a waste. Though there might be no reason the two projects cannot share some logic, like parsing the JS and such. I kind of doubt this is why its being funded. It sounds like a useful project.

Post by apgwoz » Thu, Aug 01, 2024, 12:40 AM UTC

canadahonk wrote: post #52

derdi wrote: post #20

Earlier quoted context omitted.

Presumably the idea is that any work that causes Test262 regressions is temporary, takes place in a separate branch, and is only merged to main once the branch also contains all the necessary fixes to make the regressions go away again. A new version number would only be used once that merge happens.

Exactly. The versioning system is definitely unique and controversial, but I think it fits for a fast moving project like this, so I don't have to really consider versioning which could slow development. When it becomes more stable, I'll likely move to a more traditional semver scheme from 1.0.

Post by g15jv2dp » Thu, Aug 01, 2024, 3:54 AM UTC

munificent wrote: post #106

g15jv2dp wrote: post #60

Earlier quoted context omitted.

> I think the even bigger elephant in the room is that TypeScript's type system is unsound. Can you name a single language that is used for high-performance software and whose type system is sound? To speed up the process, note that none of the obvious candidates have sound type systems.

Java, C#, Scala, Haskell, and Dart are all sound as far as I know. Soundness in all of those languages involves a mixture of compile-time and runtime checks. Most of the safety comes from the static checking, but there are a few places where the compiler defers checking to runtime and inserts checks to ensure that it's not possible to have an expression of type T successfully evaluate to a value that isn't an T. Type…