[pypy-dev] re-boxing of CPython types.

[Armin Rigo]

Hi Luke,

I think I understand the point of your work, so let me point out the
difference with our JavaScript backend.  In your work, you are fine with
emulating basic- or medium-level Python functionality, by giving up on
the details.  That's fine by itself; PyPy has a different goal for
different people, and that's why our JavaScript backend wasn't really
useful.  It was compiling custom snippets of RPython code to JavaScript,
which required advanced knowledge of type inference before being useful;
or alternatively, we could compile the *whole* PyPy interpreter to
JavaScript (if the JS backend was complete), which would not really be
useful for JavaScript-oriented people, and definitely too slow.

For an example of what I mean with "medium-level Python functionality",
just try to run any existing application in your system: it will fail
because most existing applications rely somehow on advanced features
of Python.

Of course, in the particular use case of your system, you expect most
code to be written from scratch instead of, say, people importing
Twisted in your environment.  So that's why your system is fine for its
use case, and why PyPy's JavaScript backend is far over-the-top in this
case.


A bientot,

Armin.