in reply to Re: The Deceiver
in thread Why does a Perl 5.6 regex run a lot slower on Perl 5.8?
I was trying to make a point about the fact that this code runs incredibly slower on the prepackaged RH9 Perl 5.8.0 compared to the prepackaged (Mandrake 8 I believe) Perl 5.6.1. The example above was whipped up especially for this experiment, after a period of tracking down the exact pieces of code which were slowing down my original Perl programs.
Only after noticing that the =~ /(.*?) constructs were leading to neverending pauses in the Perl 5.8.0 code, did I realize that adding a ^ anchor would eliminate the inherent ambiguity (the /s switch was on). That's how I made this short example, in which I added the extract subroutine so I can get clear results in the DProf debugger and can make direct comparisons against the Perl versions. I was astounded to see that the slow ratio was not within 1.0 and 2.0 (meaning a tad slower), but somewhere between 500.0 and 1,000.0, explaining why buying new hardware was definitely more expensive than having somebody replace all /(.*?) regexps to /^(.*?) :).