Feature #1201

Add relative group reference in back reference with nest level in regular expressions (e.g. \k<-5+1>)

Added by WoNaDo (Wolfgang NĂ¡dasi-Donner) about 9 years ago. Updated about 6 years ago.

Target version:


It should be possible to use relative group references in back reference with nest level.

Reason: As named in Ticket 1200 relative group references can be very helpful in writing subexpessions, which can be used later on as often as necessary in one regular expression.

Unfortunately back references with nest level, \k, \k, \k'n+level', and \k'n-level', do not allow relative group referencing, so they can only be used if one knows, how many normal groups are in the complete regular expression before the referenced group.

If there are relative group references possible, e.g. \k<-n+level>, \k<-n-level>, \k'-n+level', and \k'-n-level', these constructs can be used in subexpressions designed to be used more than once in a regular expression.

Related issues

Related to Ruby trunk - Feature #1200: Possibility for using named and normal groups together in regular expressionsRejected2009-02-25


#1 Updated by naruse (Yui NARUSE) over 8 years ago

This feature depends on oniguruma.

#2 Updated by marcandre (Marc-Andre Lafortune) over 8 years ago

  • Assignee set to matz (Yukihiro Matsumoto)
  • Target version changed from 1.9.1 to 2.0.0



#3 Updated by shyouhei (Shyouhei Urabe) over 7 years ago

  • Status changed from Open to Assigned



#4 [ruby-core:42603] Updated by naruse (Yui NARUSE) about 6 years ago

  • Status changed from Assigned to Closed

Ruby 1.9.1 supports this through Oniguruma 5.9.1.

Also available in: Atom PDF