> I hope I don't have any bugs here :)
Just one. :)
Your expressions all say \d instead of \d? for the second digit in
each set, while the simple one correctly has \d?. So your
expressions had an unfair advantage and as a result finish faster.
Add \d? to your expressions, and you should find that "simple",
besides probably being the easiest to read, is also the most efficient
of the expressions listed. (Note that I removed the obviously
inefficient ones.)
use strict;
use warnings;
use Benchmark 'cmpthese';
my $field = '19.12.12';
cmpthese -5, {
simple => sub {
if ( $field =~ /^[1-9]\d?\.[1-9]\d?\.[1-9]\d?$/ ) {}
},
short => sub {
if ( $field =~ /^([1-9]\d?\.){2}[1-9]\d?$/ ) {}
},
shortwoc => sub {
if ( $field =~ /^(?:[1-9]\d?\.){2}[1-9]\d?$/ ) {}
},
trickywoc => sub {
if ( $field =~ /^(?:[1-9]\d?(?:\.[1-9]\d?){2})$/ ) {}
},
};
__END__ Rate short shortwoc trickywoc simple
short 677138/s -- -23% -25% -40%
shortwoc 880536/s 30% -- -2% -22%
trickywoc 901095/s 33% 2% -- -20%
simple 1127127/s 66% 28% 25% --
second benchmark:
my $field = '19.12.02';
Rate short shortwoc trickywoc simple
short 927396/s -- -10% -12% -29%
shortwoc 1027728/s 11% -- -3% -22%
trickywoc 1055892/s 14% 3% -- -19%
simple 1310837/s 41% 28% 24% --
> Have a nice day.
You too. I learned a lot from this, so thanks.
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