AOT with type hints generated from typescript compiler

[laishere]

Would it be possible to achieve an efficient AOT compiler with type hints from typescript?

[bnoordhuis]

How would quickjs see those type hints? It operates on JS, not TS.

If you mean magic comments, that's basically what this stage 1 type annotations proposal proposes, but they're useless to a JS engine because at runtime they're descriptive, not prescriptive. A function that says it adds two numbers must still be able to handle strings as inputs.

(Also, I don't think that proposal is going anywhere. It's been sitting at stage 1 for years.)

The stage 2 structs proposal is more likely to go places and yield real improvements.

[laishere]

Thanks for reply!

I don't mean it in a standard js. And type hints should be seen by the compiler as extra information generated from typescript compiler.
It can be in js comment like

/* typehint(a: string) */
let a = func();

or in a separate file like "sourcemap"

It is just like a kind of low cost type guessing at compile time.
So we can have more efficient branch predictions when the code comes with type hints?

[bnoordhuis]

It's technically possible but we'd have to add specialized bytecode opcodes and I expect that any performance improvements will be fairly marginal. You could try it in a fork and see what happens though.

[laishere]

Sure, will do!

[guest271314]

For AOT compilation with types you can try using Facebook's Static Hermes with -typed option.