Benchmark: running Using Regexp, Using Reverse & Chop, Using Split, Using Substring, Using Unpack, each for at least 5 CPU seconds...
Using Regexp:  5 wallclock secs ( 5.39 usr + -0.01 sys =  5.38 CPU) @ 207251.30/s (n=1115012)
Using Reverse & Chop:  4 wallclock secs ( 5.23 usr +  0.00 sys =  5.23 CPU) @ 255457.74/s (n=1336044)
Using Split:  5 wallclock secs ( 5.25 usr +  0.01 sys =  5.26 CPU) @ 97116.92/s (n=510835)
Using Substring:  5 wallclock secs ( 5.25 usr + -0.02 sys =  5.23 CPU) @ 1009882.22/s (n=5281684)
Using Unpack:  5 wallclock secs ( 5.27 usr +  0.01 sys =  5.28 CPU) @ 260676.33/s (n=1376371)