On 25-Sep-12 06:18, bearophile wrote:
This line of code sorts two arrays in "lock step", according to the items of the first array:zip(first, second).sort!q{a[0] < b[0]}(); This code is handy, nice looking, short and sufficiently easy to recognize once you have seen it before.
Analyzing asm dump should help. But either way zip-sort heavily relies on proper inlining and I suspect it's not fully "unrolled".
Did you try DMD or other compilers?
It's one case where D code is better than a Python version (and this returns two tuples instead of two lists): first, second = zip(*sorted(izip(first, second), key=itemgetter(0))) But with DMD on shortish arrays of about 20-30 items (each one 24 bytes long) I've seen that D code 3-5 times slower (to be sure of such timings I have to write down a proper benchmark) than sorting the items with simple manually written sorting D code, like a bubble sort or something similar (where inside swaps items of both arrays). So if this sorting is done in inner loops or critical parts of code, you can't use that zip+sort :-( Bye, bearophile
-- Dmitry Olshansky
