I added foo_ro => sub { /^(|foob)foofoo/ foreach (@string) } (and upped the iterations) and got 
Benchmark: timing 500000 iterations of foo_or, foo_qs, foo_ro...
    foo_or:  3 wallclock secs ( 2.55 usr +  0.00 sys =  2.55 CPU) @ 19
+6386.49/s (n=500000)
    foo_qs:  3 wallclock secs ( 2.45 usr +  0.00 sys =  2.45 CPU) @ 20
+3832.04/s (n=500000)
    foo_ro:  2 wallclock secs ( 2.39 usr +  0.00 sys =  2.39 CPU) @ 20
+9205.02/s (n=500000)
           Rate foo_or foo_qs foo_ro
foo_or 196386/s     --    -4%    -6%
foo_qs 203832/s     4%     --    -3%
foo_ro 209205/s     7%     3%     --

[download]
This shows the ro doing better than even the qs. I suppose that (foob|) vs (|foob) depends on the data(?).

--traveler

In reply to Re: Re: Difference between (foo|) and (foo)? by traveler
in thread Difference between (foo|) and (foo)? by Derek2

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