# using regex
        'm//' => sub {
            my ( $first ) = $str =~ m/(.*?),/;
        },
        'm//s' => sub {
            my ( $first ) = $str =~ m/(.*?),/s;
        },

##</code><code>##

                  Rate        m//       m//s  split_unl  split_lim split_lim_sca
m//           486790/s         --        -3%       -17%       -17%          -17%
m//s          499664/s         3%         --       -15%       -15%          -15%
split_unl     585631/s        20%        17%         --        -0%           -0%
split_lim     587555/s        21%        18%         0%         --           -0%
split_lim_sca 587951/s        21%        18%         0%         0%            --