Regular Expressions Recurse into a subpattern


Example

You can recurse into a subpattern using the following constructs (depending on the flavor), assuming n is a capturing group number, and name the name of a capturing group.

  • (?n)
  • \g<n>
  • \g'0'
  • (?&name)
  • \g<name>
  • \g'name'
  • (?P>name)

The following pattern:

 \[(?<angle><(?&angle)*+>)*\]

Will match text such as: [<<><>><>] - well balanced angle brackets within square brackets. Recursion is often used for balanced constructs matching.