static HplsqlParser.Create_routine_param_itemContext getCallParameter(HplsqlParser.Expr_func_paramsContext actual,
      HplsqlParser.Create_routine_paramsContext formal, int pos) {
    String named ;
    int out_pos = pos;
    if (actual.func_param(pos).ident() != null) {
      named = actual.func_param(pos).ident().getText();
      int cnt = formal.create_routine_param_item().size();
      for (int i = 0; i < cnt; i++) {
        if (named.equalsIgnoreCase(formal.create_routine_param_item(i).ident().getText())) {
          out_pos = i;
          break;
        }
      }
    }
    return formal.create_routine_param_item(out_pos);
  }
Get call parameter definition by name (if specified) or position
hplsql/src/main/java/org/apache/hive/hplsql/functions/InMemoryFunctionRegistry.java