[pypy-dev] Re: Comments from an observer

[Carl Friedrich Bolz]

Hi Ben!

Ben.Young at risk.sungard.com wrote:
>> Because we needed a description of the Python language that is amenable
>> to analysis.  I hope this isn't a new answer to you...
> 
> I do understand that. It's just that as PyPy is a relatively complicated 
> program it follows that rpython is good for making a lot of python 
> programs amenable to analysis. (Yes as a by-product, but in my opinion an 
> incredibly powerfull and usefull one)

No. RPython is not good for making a lot of Python programs amenable for 
analysis for several reasons. One of them is that although RPython is a 
rather nice and powerful language is *is not Python* (although it 
deceptively looks like it). That means (as Michael already pointed out) 
that it is really hard to convert an existing program to RPython since 
the style of programming is just totally different. So all the people 
saying "yay, I want RPython to speed up my program" will run into deep 
problems, no matter how much the RPython toolchain will be brushed up. 
After all, the PyPy standard interpreter was written in RPython from the 
ground up.

The other problem is that you have nearly no standard library available 
in RPython, which is also something that is not easy to change. And it 
is easy to forget just how much most python programs are dependent on 
the stdlib :-).

Cheers,

Carl Friedrich Bolz