D'oh! I optimized the split but not the regex :( That'll teach me to be careless. For honesty's sake:
timethese(1000000, {
Regex => '$a=$1 if $myvar =~ /^[^,]+,([^,]+)/',
Split1 => '$result = (split /,/, $myvar)[1]',
Split2 => '$result = (split /,/, $myvar, 4)[1]',
Split3 => '$result = (split /,/, $myvar, 3)[1]'
});
Benchmark: timing 1000000 iterations of Regex, Split1, Split2, Split3.
+..
Regex: 14 wallclock secs (14.12 usr + 0.00 sys = 14.12 CPU)
Split1: 17 wallclock secs (16.54 usr + 0.00 sys = 16.54 CPU)
Split2: 16 wallclock secs (16.75 usr + 0.00 sys = 16.75 CPU)
Split3: 14 wallclock secs (13.02 usr + 0.00 sys = 13.02 CPU)
I'm going to cry myself to sleep tonight.
Curiously, though, it was the null assignments that appeared to be killing the efficiency ($a=$1, $b=$2, $c=$3, $d=$4) much more than the unoptimized regex. Hmmm....
Cheers,
Ovid
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