length of search string: 20904
           Rate Rregex  Fregex  Rsubstr  Rindex Fsubstr Findex 
Rregex  11708/s      --    -16%    -41%    -45%    -61%    -70%
Fregex  14005/s     20%      --    -29%    -35%    -54%    -64%
Rsubstr 19721/s     68%     41%      --     -8%    -35%    -50%
Rindex  21423/s     83%     53%      9%      --    -29%    -45%
Fsubstr 30362/s    159%    117%     54%     42%      --    -22%
Findex  39142/s    234%    179%     98%     83%     29%      --