code: /*
   * 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.
   */
  /*
   * $Id$
   */
  package org.apache.xpath.functions;
  
  import org.apache.xalan.res.XSLMessages;
  import org.apache.xpath.Expression;
  import org.apache.xpath.ExpressionOwner;
  import org.apache.xpath.XPathVisitor;
  import org.apache.xpath.res.XPATHErrorResources;
  
  /**
   * Base class for functions that accept an undetermined number of multiple
   * arguments.
   * @xsl.usage advanced
   */
  public class FunctionMultiArgs extends Function3Args
  {
      static final long serialVersionUID = 7117257746138417181L;
  
    /** Argument expressions that are at index 3 or greater.
     *  @serial */
    Expression[] m_args;
    
    /**
     * Return an expression array containing arguments at index 3 or greater.
     *
     * @return An array that contains the arguments at index 3 or greater.
     */
    public Expression[] getArgs()
    {
      return m_args;
    }
  
    /**
     * Set an argument expression for a function.  This method is called by the
     * XPath compiler.
     *
     * @param arg non-null expression that represents the argument.
     * @param argNum The argument number index.
     *
     * @throws WrongNumberArgsException If a derived class determines that the
     * number of arguments is incorrect.
     */
    public void setArg(Expression arg, int argNum)
            throws WrongNumberArgsException
    {
  
      if (argNum < 3)
        super.setArg(arg, argNum);
      else
      {
        if (null == m_args)
        {
          m_args = new Expression[1];
          m_args[0] = arg;
        }
        else
        {
  
          // Slow but space conservative.
          Expression[] args = new Expression[m_args.length + 1];
  
          System.arraycopy(m_args, 0, args, 0, m_args.length);
  
          args[m_args.length] = arg;
          m_args = args;
        }
        arg.exprSetParent(this);
      }
    }
    
    /**
     * This function is used to fixup variables from QNames to stack frame 
     * indexes at stylesheet build time.
     * @param vars List of QNames that correspond to variables.  This list 
     * should be searched backwards for the first qualified name that 
     * corresponds to the variable reference qname.  The position of the 
     * QName in the vector from the start of the vector will be its position 
     * in the stack frame (but variables above the globalsTop value will need 
     * to be offset to the current stack frame).
     */
    public void fixupVariables(java.util.Vector vars, int globalsSize)
    {
      super.fixupVariables(vars, globalsSize);
      if(null != m_args)
      {
        for (int i = 0; i < m_args.length; i++) 
        {
          m_args[i].fixupVariables(vars, globalsSize);
        }
      }
    }
  
    /**
     * Check that the number of arguments passed to this function is correct.
     *
     *
     * @param argNum The number of arguments that is being passed to the function.
     *
     * @throws WrongNumberArgsException
     */
    public void checkNumberArgs(int argNum) throws WrongNumberArgsException{}
  
    /**
     * Constructs and throws a WrongNumberArgException with the appropriate
     * message for this function object.  This class supports an arbitrary
     * number of arguments, so this method must never be called.
     *
     * @throws WrongNumberArgsException
     */
    protected void reportWrongNumberArgs() throws WrongNumberArgsException {
      String fMsg = XSLMessages.createXPATHMessage(
          XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
          new Object[]{ "Programmer's assertion:  the method FunctionMultiArgs.reportWrongNumberArgs() should never be called." });
  
      throw new RuntimeException(fMsg);
    }
  
    /**
     * Tell if this expression or it's subexpressions can traverse outside
     * the current subtree.
     *
     * @return true if traversal outside the context node's subtree can occur.
     */
    public boolean canTraverseOutsideSubtree()
    {
  
      if (super.canTraverseOutsideSubtree())
        return true;
      else
      {
        int n = m_args.length;
  
        for (int i = 0; i < n; i++)
        {
          if (m_args[i].canTraverseOutsideSubtree())
            return true;
        }
  
        return false;
      }
    }
    
    class ArgMultiOwner implements ExpressionOwner
    {
    	int m_argIndex;
    	
    	ArgMultiOwner(int index)
    	{
    		m_argIndex = index;
    	}
    	
      /**
       * @see ExpressionOwner#getExpression()
       */
      public Expression getExpression()
      {
        return m_args[m_argIndex];
      }
  
  
      /**
       * @see ExpressionOwner#setExpression(Expression)
       */
      public void setExpression(Expression exp)
      {
      	exp.exprSetParent(FunctionMultiArgs.this);
      	m_args[m_argIndex] = exp;
      }
    }
  
     
      /**
       * @see org.apache.xpath.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
       */
      public void callArgVisitors(XPathVisitor visitor)
      {
        super.callArgVisitors(visitor);
        if (null != m_args)
        {
          int n = m_args.length;
          for (int i = 0; i < n; i++)
          {
            m_args[i].callVisitors(new ArgMultiOwner(i), visitor);
          }
        }
      }
      
      /**
       * @see Expression#deepEquals(Expression)
       */
      public boolean deepEquals(Expression expr)
      {
        if (!super.deepEquals(expr))
              return false;
  
        FunctionMultiArgs fma = (FunctionMultiArgs) expr;
        if (null != m_args)
        {
          int n = m_args.length;
          if ((null == fma) || (fma.m_args.length != n))
                return false;
  
          for (int i = 0; i < n; i++)
          {
            if (!m_args[i].deepEquals(fma.m_args[i]))
                  return false;
          }
  
        }
        else if (null != fma.m_args)
        {
            return false;
        }
  
        return true;
      }
  }
  