Re: [jamboost] Re: Bjam in C++?

From: Vladimir Prus (ghost_at_[hidden])
Date: 2004-06-26 07:55:23

David Abrahams wrote:

> >> I think that strategically, we better implement core features in a
> >> language which is fast -- C++. I suspect that converting not very
> >> efficient code into yet another language might have dramatic effect
> >> on performance.
>
> That depends. At least Python can clean up its strings, for example.

I think that symple-minded conversion will turn

local a = foo bar ;

into 

a = ["foo", "bar"] ;

which would not use jam string-caching and might take a lot more memory. An 
writing optimizing Jam->Python compiler is scary.

> > I agree. Scons is a nice build system in many ways being able to use a
> > 'proper' language to define your builds is good but it suffers from being
> > pure Python as its dependency checking is just not fast enough for large
> > projects.
>
> I'm not sure that has anything whatsoever to do with Python. Scons'
> standard dependency checking ignores file dates and examines contents
> instead. You can turn that off and use a more Jam/Make-like date
> checking algorithm. Is it still too slow?

I don't know about that... but I suspect rewrite of "toolset.flags" in C++ 
will be twice as fast as in Python.

- Volodya