use Benchmark 'cmpthese';
my $str1 = 'foobarbazqux';
my $str2 = 'foobar';
my $str2len = length $str2;
cmpthese (3e6, {
regex => sub { $str1 =~ /\Q$str2/; },
regex2 => sub { $str1 =~ /\Q$str2/o; }, ## probably useless test,
+see japhy's comment below
index => sub { index $str1, $str2; },
substr => sub { $str2 eq substr $str1, 0, length $str2; },
substr2 => sub { $str2 eq substr $str1, 0, $str2len; },
});
__END__
Rate regex regex2 substr substr2 index
regex 1063830/s -- -13% -25% -43% -72%
regex2 1229508/s 16% -- -14% -34% -68%
substr 1421801/s 34% 16% -- -23% -63%
substr2 1851852/s 74% 51% 30% -- -51%
index 3797468/s 257% 209% 167% 105% --
The index solution is clearly superior to the others. It's interesting to see the improvements of regex2 and substr2 over their unoptimized counterparts.
Update: I forgot that the OP was matching at the beginning of the string. This is a better benchmark:
use Benchmark 'cmpthese';
my $str1 = 'foobarbazqux';
my $str2 = 'foobar';
my $str2len = length $str2;
cmpthese (3e6, {
regex => sub { $str1 =~ /^\Q$str2/; },
index => sub { 0 == index $str1, $str2; },
substr => sub { $str2 eq substr $str1, 0, length $str2; },
substr2 => sub { $str2 eq substr $str1, 0, $str2len; },
});
__END__
Rate regex substr substr2 index
regex 671141/s -- -59% -65% -71%
substr 1630435/s 143% -- -16% -30%
substr2 1935484/s 188% 19% -- -17%
index 2343750/s 249% 44% 21% --
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