Backtracking Control Verbs

• (*MARK:name)

• • when executed “marks” the current position in the string and gives it a name.
  • Provides a way to see what “path” the engine has taken through the pattern.
  • /foo(*:A)|bar(*:B)|baz(*:C)/
  • • and print $REGMARK;
  • (*:name) is a short form of (*MARK:name)
  • Invented for Spam-Assassin