[pypy-dev] Javascript interpreter and r_uint

[Maciej Fijalkowski]

On Thu, Dec 6, 2012 at 1:58 AM, Jonathan Slenders <jonathan at slenders.be> wrote:
> Hi all,
>
> Yesterday, I did some experiments with the existing javascript interpreter
> that was written in RPython. [1]
> It worked very well when interpreted by CPython, but failed to translate to
> C because of unsigned int issues.
>
> Quite a few times, unsigned and signed objects were compared or added, or
> one asigned to the other. (I'm not entirely sure.)
> But I had to replace r_uint32 by r_int32 and r_uint by r_int, about 25
> times, before I could translate anything.

Good question, I have no idea. Can't you use normal integers in those places?

>
> So, my question is. What is the reason for having unsigned integers in the
> javascript interpreter?
>
> Apart from that, it works great, and I translated the interpreter even with
> the --sandbox option!
>
> A related question. how mature is the interpreter? It seems to run pretty
> stable, although there hasn't been any development done since june 2011.
> I'd like to choose this instead of Google's V8, because that way I can keep
> the same sandbox hypervisor for both Python and Javascript.

The interpreter is relatively complete, however it does require fixing
a lot of corner cases from ECMA tests. There are quite a few missing
pieces:

* the correct semicolon insertion requires a different parser
(standard says LL(1))

* regular expressions are not supported

* xml literals are unsupported

Cheers,
fijal