Joel de Guzman wrote:
John Bytheway wrote:
string::begin() return a non-const reference?), but anyway. Here are the icc results (Intel Core2 Quad 2.83GHz, Gentoo):
Loop count: 10000000 Parsing: 42.5 xpressive: 4.28591 spirit-quick(static): 1.4721 spirit-quick_new(threadsafe): 1.46949 spirit-grammar(threadsafe/reusable): 1.59846
and gcc-4.4.0:
Loop count: 10000000 Parsing: 42.5 xpressive: 3.62948 spirit-quick(static): 1.02657 spirit-quick_new(threadsafe): 1.00637 spirit-grammar(threadsafe/reusable): 1.01748
gcc 4.3 is still ICEing.
Those are good numbers. It shows that the effect of the virtual function call of the spirit grammar rules is obviated out of existence!
For the record, this one shows the xpressive code using spirit numeric parsers to convert the string to numbers, right?
Correct.
Will the original OP please (PLEASE!) come forward and post his original hand-coded program? This is SOOO confusing!
Well, in case he doesn't, I've thrown together an implementation of core::to_number based on Robert's description of it. I had to guess at the interface, and I didn't verify correctness. I also had to implement two error routines; I made them both "throw 0;". I also tweaked the xpressive code so that it didn't copy the sub_match objects to strings before using qi to parse out the doubles and ints. That sped it up slightly (gcc 4.4.0 again): Loop count: 10000000 Parsing: 42.5 original-custom: 2.08637 xpressive: 2.94329 spirit-quick(static): 1.02784 spirit-quick_new(threadsafe): 1.03306 spirit-grammar(threadsafe/reusable): 1.00213 although I'm slightly concerned with what happened when I changed the string to be parsed: Loop count: 10000000 Parsing: 425/500 original-custom: 1.6307 xpressive: 116.992 spirit-quick(static): 0.552722 spirit-quick_new(threadsafe): 0.53429 spirit-grammar(threadsafe/reusable): 0.680257 Why is the xpressive code so slow here? The parsing is more complex in this case, but I wouldn't think it was this bad! Perhaps I broke it somehow... New code attached (also includes other minor changes I had to make to get things to compile). If someone writes core::numeric_cast then the 'original' xpressive code can be used. John Bytheway