in reply to Re: Regex help
in thread Regex help

I can't believe you missed out on this opportunity to wave (--) the magic wand variable ($|) to get only the odd or even elements of a list: 
print grep --$|,($|||=1)&& /\b(\w+)\b(?=(.*?)\b\1\b)/g'

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Re: Re: Re: Regex help
by BUU (Prior) on Jan 30, 2004 at 08:03 UTC
    What the good lord does that code do? Or rather, how does it work? Whats the $|||=1 bit, etc?
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      That bit is just charging up the magic wand. It can just as well be a separate statement: 
      $| = 1;
print grep --$|, /\b(\w+)\b(?=(.*?)\b\1\b)/g'

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      To get even elements instead of odd elements, you just start with the magic wand in the other position: 
      print grep --$|,($|&&=0)|| /\b(\w+)\b(?=(.*?)\b\1\b)/g'

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      or: 
      $| = 0;
print grep --$|, /\b(\w+)\b(?=(.*?)\b\1\b)/g'

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      Why ||= and &&= instead of = is left as an excercise for the reader. Hope that clears things up for you :)
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