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in reply to Re^5: Finding repeat sequences. (only mostly regex)
in thread Finding repeat sequences.

No. Any incomplete rep will alway be at the end of the string. 'fredf', 'fredfr', 'fredfre', 'fredfredfre' etc.

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  • Comment on Re^6: Finding repeat sequences. (only mostly regex)

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Re^7: Finding repeat sequences. (only mostly regex)
by choroba (Cardinal) on Jun 18, 2013 at 20:44 UTC
    Right. In fredfr, the ed will be matched by the .* between the repetitions. It corresponds to the missing part of the last repetition. Or am I missing something?
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      I am so sorry. You've done the same flip that tye did, capturing the partial rep rather than the complete rep. Threw me completely.

      With a couple of enhancements that works for the 1 rep/1 partial case:

      $s = 'aaaabaaaabaaaaabaaaab';;

$s =~ /^((.*).*)\2$/ and print "$1/$2";;
aaaabaaaaba/aaaabaaaab

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      And still works for that when enhanced to allow for more than 1 complete rep:

      $s =~ /^((.*).*)\1*\2$/ and print "$1/$2";;
aaaabaaaaba/aaaabaaaab

      [download]

      But then fails when given more than one complete rep:

      $s = 'aaaabaaaabaaaaabaaaabaaaaabaaaab';;

$s =~ /^((.*).*)\1*\2$/ and print "$1/$2";;
aaaabaaaabaaaaabaaaaba/aaaabaaaab

      [download]
      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
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