my $buf;
sub gen_salva2 {
    while (length $buf < $len) {
        $buf .= $set[rand @set] for (1..$len*100);
        $buf =~ s/(.)\1{$max_reps,}/$1 x $max_reps/ge;
    }
    substr($buf, -$len, $len, '');
}

##</code><code>##

elements: 6 max_reps: 2
              Rate   salva2     salva almut_mod3 almut_mod4 almut_mod2     almut
salva2      1077/s       --      -98%       -98%       -98%       -98%      -98%
salva      54086/s    4922%        --       -10%       -13%       -13%      -17%
almut_mod3 59766/s    5450%       11%         --        -4%        -4%       -8%
almut_mod4 61953/s    5653%       15%         4%         --        -1%       -5%
almut_mod2 62270/s    5682%       15%         4%         1%         --       -5%
almut      65222/s    5956%       21%         9%         5%         5%        --

##</code><code>##

my $buf;
sub gen_salva2 {
    print "$buf\n";
    while (length $buf < $len) {
        $buf .= $set[rand @set] for (1..$len*100);
        $buf =~ s/(.)\1{$max_reps,}/$1 x $max_reps/ge;
    }
    substr($buf, -$len, $len, '');
}