tr is MUCH faster than s though. I tried to work this out but didn’t hit on trizen’s cleverness. So…

# (v5.18.2) built for darwin-2level
    'tr' => sub {
        $str =~ tr/M/~/sr=~tr/~//;
    },
-- 
count      3
regex      3
regex2     3
split      3
tr         3

            Rate regex2  split  regex  count     tr
regex2  169354/s     --   -62%   -65%   -75%   -94%
split   446500/s   164%     --    -7%   -34%   -85%
regex   481882/s   185%     8%     --   -29%   -84%
count   674634/s   298%    51%    40%     --   -78%
tr     3044813/s  1698%   582%   532%   351%     --

[download]

Update: as trizen noted in his code, the /r flag to tr came in at 5.14. It won’t work on older Perls (update: <- stupid apostrophe begone).

In reply to Re^5: Can you write a faster code to perform this task? by Your Mother
in thread Can you write a faster code to perform this task? by Anonymous Monk

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