Backtracking Control Verbs

• (*COMMIT)

• • When backtracked into causes the pattern to fail outright. The engine will not try to match the pattern at any other start point.
  • In Perl6 this is called... <commit>
  • 'foofoofoobar' =~ / (fo+)* (*COMMIT) [BC]ar /x;
  • will fail, and will do so quickly.
  • 'foofoofoobar' =~ / (fo+)* [BC]ar /x;
  • won't, although it could be worse as the super-linear cache kicks in. (see commit.pl)