Well then, wouldn't it make sense for PyPy to use Shedskin and its definition of Restricted Python?
I have heard repeatedly that PyPy RPython is very difficult to use. Then why isn't PyPy using Shedskin to compile its PyPy-Jit? Sarvi On Sep 2, 11:59 pm, John Nagle <na...@animats.com> wrote: > On 9/2/2010 10:30 PM, sarvi wrote: > > > > > > > On Sep 2, 2:19 pm, John Nagle<na...@animats.com> wrote: > >> On 9/2/2010 1:29 AM, sarvi wrote: > > >>> When I think about it these restrictions below seem a very reasonable > >>> tradeoff for performance. > > >> Yes. > > >>> And I can use this for just the modules/sections that are performance > >>> critical. > > >> Not quite. Neither Shed Skin nor RPython let you call from > >> restricted code to unrestricted code. That tends to happen > >> implicitly as objects are passed around. It's the global > >> analysis that makes this work; when you call something, you > >> need to know more about it than how to call it. > > > It should technically be possible to allow Python to call a module > > written in RPython? > > The problem is that, in a language where everything is an object, > everything you call calls you back. > > The basic performance problem with CPython comes from the fact > that it uses the worst-case code for almost everything. Avoiding > that requires global analysis to detect the places where the code > clearly isn't doing anything weird and simpler code can be used. > Again, look at Shed Skin, which represents considerable progress > made by one guy. With more resources, that could be a very > good system. > > John Nagle -- http://mail.python.org/mailman/listinfo/python-list
