Re^2: regex at word boundary

The code at that Re^5: regex at word boundary fails on overlapping palindromes, not that I'm aware of any that exist in the wild. Such that adding

nested testest detsen nested
i prefer pi ip referp

yeilds:


line 7:
(0) "nested testest detsen nested"
(7) "testest detsen nested"
(15) "detsen nested"
(22) "nested"

line 8:
(0) "i prefer pi ip referp"
(2) "prefer pi ip referp"
(9) "pi ip referp"
(12) "ip referp"
(15) "referp"

I also tested it on a handy text file of 79,569 lines and it ran much slower than the code I listed above, modified to just test on each line, not each paragraph.

sunorccws04 ~$ time ./mr_pal.pl trf > mr.out

real    1m2.161s
user    1m1.210s
sys     0m0.280s

sunorccws04 ~$ time ./qm_pal.pl trf > qm.out

real    2m53.492s
user    2m49.070s
sys     0m1.690s

trf is the output of a tcpdump session. Other data sets are sure to produce differing comparative speeds.

Be Appropriate && Follow Your Curiosity

Comment on Re^2: regex at word boundary

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Re^3: regex at word boundary by QM (Parson) on Dec 12, 2005 at 18:16 UTC
Are you comparing apples to apples? Does the other code find overlapping palindromes? -QM -- Quantum Mechanics: The dreams stuff is made of	[reply]
Re^4: regex at word boundary by mikeraz (Friar) on Dec 12, 2005 at 18:22 UTC
It does catch the overlapping. But I'm not comparing apples to apples because the RE in your code isn't working on my Solaris 5.6.1 code and it's generating many extra matches. Be Appropriate && Follow Your Curiosity	[reply]