Rate  split1 substr1 using_str_bit_ops_and_tr map_split
split1                   1.85/s      --    -94%                    -100%     -100%
substr1                  32.9/s   1676%      --                     -95%      -98%
using_str_bit_ops_and_tr  714/s  38390%   2067%                       --      -62%
map_split                1898/s 102263%   5663%                     166%       --