content: /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.activemq.filter.function;
  
  import org.apache.activemq.filter.FunctionCallExpression;
  import org.apache.activemq.filter.MessageEvaluationContext;
  
  /**
   * Filter function that matches a value against a list of values and evaluates to an indicator of membership in the
   * list.  For example:
   * <p/>
   * <p style="margin-left: 4em">
   * INLIST( SPLIT('1,2,3', ',') , '2' )
   * </p>
   * <p/>
   * Note that the first argument must be a List.  Strings containing lists are not acceptable; for example,
   * INLIST('1,2,3', '1'), will cause an exception to be thrown at evaluation-time.
   */
  
  public class inListFunction implements FilterFunction {
      /**
       * Check whether the given expression is a valid call of this function.  Two arguments are required.  Note that
       * the evaluated results of the arguments will be compared with Object#equals().
       *
       * @param    expr - the expression consisting of a call to this function.
       * @return true - if the expression is valid; false - otherwise.
       */
  
      public boolean isValid(FunctionCallExpression expr) {
          if (expr.getNumArguments() != 2)
              return false;
  
          return true;
      }
  
  
      /**
       * Check whether the given expression, which consists of a call to this function, evaluates to a Boolean.
       * If the function can return different more than one type of value at evaluation-time, it must decide whether
       * to cast the result to a Boolean at this time.
       *
       * @param    expr - the expression consisting of a call to this function.
       * @return true - if the expression is valid; false - otherwise.
       */
  
      public boolean returnsBoolean(FunctionCallExpression expr) {
          return true;
      }
  
  
      /**
       * Evalutate the given expression, which consists of a call to this function, in the context given.  Checks
       * whether the second argument is a member of the list in the first argument.
       *
       * @param    expr - the expression consisting of a call to this function.
       * @param    message_ctx - the context in which the call is being evaluated.
       * @return Boolean - the result of the evaluation.
       */
  
      public Object evaluate(FunctionCallExpression expr, MessageEvaluationContext message_ctx)
              throws jakarta.jms.JMSException {
          java.util.List arr;
          int cur;
          Object cand;
          boolean found_f;
  
          arr = (java.util.List) expr.getArgument(0).evaluate(message_ctx);
          cand = expr.getArgument(1).evaluate(message_ctx);
  
          cur = 0;
          found_f = false;
          while ((cur < arr.size()) && (!found_f)) {
              found_f = arr.get(cur).equals(cand);
              cur++;
          }
  
          return found_f;
      }
  }
  