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Re^2: RegEx + vs. {1,}

by Athanasius (Canon)
on Oct 10, 2012 at 16:03 UTC ( #998250=note: print w/replies, xml ) Need Help??

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  1. or download this
    my %seen;
        ++$seen{$1}, pos($string) -= length($1) - 1 while $string =~ /(\w{
  2. or download this
      (?{$seen{$1}++})         run this block of Perl code
      (?!)                     fail
  3. or download this
    (*FAIL) (*F) 
    This pattern matches nothing and always fails. It can be used to force
    + the engine to backtrack. It is equivalent to (?!), but easier to rea
    +d. In fact, (?!) gets optimised into (*FAIL) internally.
  4. or download this
    $string =~ /(\w{2,})(?{$seen{$1}++})(?!)/;

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