DB<1> $a="abcdabcd"

   DB<2> p $a =~ /[0-9a-f]{4|8}/

   DB<3> p $a =~ /[0-9a-f]{4}/
1
   DB<4> p $a =~ /[0-9a-f]{8}/
1

[download]

NB-the display is eating the [] square brackets up there.

lots can follow from this:
- why no error on the 1st line
- am I really the 1st ? ;-)
- whats it mean currently ? (this I can answer) 

   1: BRANCH(15)
   2:   ANYOF[0-9a-f](13)
  13:   EXACT <{4>(18)
  15: BRANCH(18)
  16:   EXACT <8}>(18)
  18: END(0)

[download]

thats not what I expected, wouldnt you tacitly expect perl to do something similar to what it does with {4,8} there ? or is that ambiguous ?

given the availability of \, which is needed to get literal reading of []() chars, whats the harm ?

(He baits the hook, chum the water... Dont we have some regex-monsters lurking here ?

Janitored by Corion: Added formatting, code tags, as per Writeup Formatting Tips

In reply to what means this regex? $x = qr/[0-9a-f]{4|8}/ by kidongrok

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