sclass NewWoody {
  Map<S, BBRule> rulesByName;
  new L<BBRule> badRules;
  S lastOutput;
  BBRule activeRule;

  *() {
    rulesByName = indexFieldAsCIMap('listName, bb_allRules());
  }
  
  *(NewWoody w) {
    copyFields(w, this, 'rulesByName, 'badRules);
  }
  
  void processInput(S input) {
    temp tempSetTL(ctxContext_var(), nu(CtxContext, +input));
    new L<BBRule> matching;
    for (BBRule r : valuesList(rulesByName)) {
      continue unless ruleExpressionMatches(r);
      matching.add(r);
    }
    
    lastOutput = null;
    activeRule = first(matching);
    if (activeRule != null)
      lastOutput = random(activeRule.answers);
  }

  bool ruleExpressionMatches(BBRule r) {  
    continue if empty(r.expression);
    try {
      ret ctxEvalCondition(r.expression);
    } catch print e {
      badRules.add(r);
      rulesByName.remove(r.listName);
      false;
    }
  }
  
  bool listsMatching(S input) {
    temp tempSetTL(ctxContext_var(), nu(CtxContext, +input));
    ret [BBRule r : valuesList(rules) | ruleExpressionMatches(r)];
  }
}