lib/ometa/ometa/base.js
function(rule) {
      var state = this.bt.current_state();
      try { return rule.call(this); } 
      catch(f) {
        this.bt.catch_mismatch(f);
        this.bt.restore(state);
      }
    }
function(rule) {
      var state = this.bt.current_state();
      try { return rule.call(this); } 
      catch(f) {
        this.bt.catch_mismatch(f);
        this.bt.restore(state);
      }
    }
function ( rule ) { var state = this . bt . current_state ( ) ; try { return rule . call ( this ) ; } catch ( f ) { this . bt . catch_mismatch ( f ) ; this . bt . restore ( state ) ; } }
Optional occurance of rule rule?
Optional occurance of rule rule?