според мен точно този регулярен е това, което трябва. дори да допуснем, че имаш "бързо напускане" (last), пак е по-бавно от регулярната машина:

#!/usr/bin/perl



use strict;

use Benchmark qw(:all);



$main::string = 'aaaaaaaaaa';

$main::buffer = 'a';

@main::array_full = split '', $main::string;

@main::array_part = qw(a b a a a a a a a a);



my $result = timethese(10_000_000, {

        'equal_full' => '$main::buffer eq $_ or last for @main::array_full;',

        'equal_part' => '$main::buffer eq $_ or last for @main::array_part;',

        'regex'      => '$main::string =~ /^\Q$main::buffer\E+$/o',

});



cmpthese( $result );



__END__



stdout:



Benchmark: timing 10000000 iterations of equal_full, equal_part, regex...

equal_full: 58 wallclock secs (28.92 usr +  0.13 sys = 29.05 CPU) @ 344234.08/s (n=10000000)

equal_part: 11 wallclock secs ( 8.98 usr +  0.00 sys =  8.98 CPU) @ 1113585.75/s (n=10000000)

     regex:  9 wallclock secs ( 8.05 usr + -0.01 sys =  8.04 CPU) @ 1243781.09/s (n=10000000)

                Rate equal_full equal_part      regex

equal_full  344234/s         --       -69%       -72%

equal_part 1113586/s       223%         --       -10%

regex      1243781/s       261%        12%         --