IMatchable (MatchNode matchNode, int index) { if (matchNode.getType() != MatchNode.MATCHNODE_EXPRENT) { return null; } List<Exprent> lstAllExprents = getAllExprents(); if (lstAllExprents == null || lstAllExprents.isEmpty()) { return null; } String position = (String)matchNode.getRuleValue(MatchProperties.EXPRENT_POSITION); if (position != null) { if (position.matches("-?\\d+")) { return lstAllExprents.get((lstAllExprents.size() + Integer.parseInt(position)) % lstAllExprents.size()); // care for negative positions } } else if (index < lstAllExprents.size()) { // use 'index' parameter return lstAllExprents.get(index); } return null; }