On 3/5/2009 8:51 AM, Dag Sverre Seljebotn wrote:
What's your take on Blitz++? Around here when you say C++ and numerical in the same sentence, Blitz++ is what they mean.
I have not looked at it for a long time (8 years or so). It is based on profane C++ templates that makes debugging impossible. The compiler does not emit meaningful diagnostic messages, and very often the compiler cannot tell on which line the error occurred. It was efficient for small arrays if loops could be completely unrolled by the template metaprogram. For large arrays, it produced intermediate arrays as no C++ compiler could do escape analysis.
Introducing this syntax would actually mean less time to focus on "real usability issues" like that. OTOH, if the syntax I propose is superior, it's better to introduce it early in a long-term perspective.
There is not much difference between cdef int[:,:] array and cdef numpy.ndarray[int, dim=2] array except that the latter is a Python object. The only minor issue with that is the GIL. On the other hand, the former is not a Python object, which means it is not garbage collected. S.M.