Front page | perl.perl5.porters |
Postings from September 2013
> Part of the reason, I think, was that v5.6 and earlier's sort was a > quicksort, and hence not a stable sort. Stability was definitely a feature, but my best argument to Jarkko was that far too many common sequences (organ pipe, sawtooth, etc.) went quadratic, and Peter Mcilroy's merge sort did a particularly nice job on sequences with pre-existing order (linear time on sorted input). The only sequences (that I could think of, anyway) where it was clear that qsort would outperform merge sort were those containing many repetitions of a small number (k) of keys. Qsort's "fat pivot" guaranteed that only k passes would be required, where merge sort might need log N. My email address in pp_sort.c is shown as jpl@research.att.com. That will stop working in a year or so. Better would be jpl.jpl@gmail.com. Peter is no longer at Lucent, so his email address, pmcilroy@lucent.com, probably stopped working about a decade ago. I don't have a current email address for him. I have no strong opinion about removing qsort. Seems like a good idea to me.Thread Previous | Thread Next