On Thu, Sep 24, 2009 at 12:07 AM, Sturla Molden <sturla@molden.no> wrote:
David Cournapeau skrev:
It can be a full rewrite, but still should be sent as patches. If I am the one to review, I would prefer this way. That's especially important to track regressions.
Well.. I didn't intend this for inclusion in SciPy, at least not in the beginning. I needed it for some neuroscience software I am writing.
It is a fundamental problem of C++. Different compilers do not propagate exceptions the same way, and that's a problem when different compilers are involved (happens easily when the C and C++ compilers are not the same, for example). That has been a problem on every new platform I have tried to port numpy and scipy to.
Does this mean we cannot use g++ to compile extensions at all, when Python VM is compiled with MSVC?
Oh, you certainly *can*, as we can use gcc to compile extensions against python built with MS compiler. But there are limitations - with C, those limitations are known, with C++, they become atrocious once you use the C++ runtime (RTTI, exception, etc...). I had to debug some stuff in sparsetools on windows 64 bits a few days ago, and this was horrible because the exceptions are lost between DLL.
I don't like the complexity of C++. But it has some advantages over C for scientific computing; notably STL containers, templates for generics, the std::complex<> type, and so on.
For basic templates, the .src stuff is good enough. For complex, yes, that's a bit of a pain, although you could use the C99 complex type if you only care about modern C compilers in your own extension.
I personally like exceptions because they remove the need for lot or error checking.
I call this a disadvantage :) And having exceptions in a language without gc causes more trouble than it worths IMHO. Exception-safe C++ is incredibly hard to do right.
In C, we can achieve almost the same effect using setjmp/longjmp. Is that bad style as well?
The standard way to handle errors in C code using the python API is goto. It works well, and if you need to jump several calls, you can always use python exception mechanism. cheers, David