in reply to RE: RE (tilly) 2: Regex'ing backreferences
in thread Regex'ing backreferences

Your current regex is: 
m{
  foo
  (             # save to $1
    [^b]*       # 0 or more non-b characters
    (?:
      b+        # 1 or more b's
      (?:
        a(?!r)  # an 'a' NOT followed by an 'r'
        |       # or
        [^a]    # a non-a character
      )
      [^b]*     # 0 or more non-b characters
    )*          # that whole b... subset, 0 or more times
  )
  foo           # and foo
}x;

[download]
That incorrectly matches "foobbarfoo".

Again, optimization is the root of all evil. :-)

Replies are listed 'Best First'.
RE: RE (tilly) 4 (good try): Regex'ing backreferences
by japhy (Canon) on Sep 21, 2000 at 18:28 UTC
    Ok. Changed it: 
    m{
  foo
  (             # save to $1
    [^b]*       # 0 or more non-b characters
    (?:
      (?>b+)    # 1 or more b's (NO BACKTRACKING!)
      (?:
        a(?!r)  # an 'a' NOT followed by an 'r'
        |       # or
        [^a]    # a non-a character
      )
      [^b]*     # 0 or more non-b characters
    )*          # that whole b... subset, 0 or more times
  )
  foo           # and foo
}x;

    [download]


    $_="goto+F.print+chop;\n=yhpaj";F1:eval
[reply]
[d/l]

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