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/*
 * Copyright Matt Palmer 2012-2013, All rights reserved.
 *
 * This code is licensed under a standard 3-clause BSD license:
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer.
 * 
 *  * Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 * 
 *  * The names of its contributors may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */

package net.byteseek.parser.tree.node;

import java.util.Collections;
import java.util.Iterator;

import net.byteseek.parser.ParseException;
import net.byteseek.parser.tree.ParseTree;
import net.byteseek.parser.tree.ParseTreeType;


/**
 * An immutable base implementation of ParseTree, that only has a type.
 * This implementation is not particularly useful to instantiate directly, although that is not
 * prohibited.  This class is intended to be sub-classed, with particular types of nodes implementing
 * their own specific functionality, with this class providing default behaviour.
 * 
 * Asking for a byte, int or text value will throw a {@link ParseException}.  Subclasses which 
 * provide those values need only override the specific method for their type of value.  
 * It will always provide an empty list of child nodes, and false if asked if the value is inverted.
 * 
 * @author Matt Palmer
 */
public class BaseNode implements ParseTree {

  private final ParseTreeType type;
  
  public static final ParseTree ANY_NODE = new BaseNode(ParseTreeType.ANY);
  
  /**
   * Constructs a base node of the given type.
   * 
   * @param type The type of the parse tree node.
   */
  public BaseNode(final ParseTreeType type) {
    this.type = type;
  }
  
  /**
   * {@inheritDoc}
   */
  @Override
  public ParseTreeType getParseTreeType() {
    return type;
  }

  /**
   * Always throws a {@link ParseException}.
   */
  @Override
  public byte getByteValue() throws ParseException {
    throw new ParseException("No byte value is available for the node " + this);
  }

  /**
   * Always throws a {@link ParseException}.
   */  
  @Override
  public int getIntValue() throws ParseException {
    throw new ParseException("No int value is available for the node " + this);
  }

  /**
   * Always throws a {@link ParseException}.
   */
  @Override
  public String getTextValue() throws ParseException {
    throw new ParseException("No text value is available for the node " + this);
  }

  /**
   * Always returns false.
   */
  @Override
  public boolean isValueInverted() {
    return false;
  }
  
  
  @Override
  public int getNumChildren() {
	  return 0;
  }
  
  @Override
  public ParseTree getChild(final int childIndex) {
	  throw new IndexOutOfBoundsException("There are no children in the node: " + this);
  }
  
  @Override
  public String toString() {
	  return getClass().getSimpleName() + "[" + type + ']';
  }

	@Override
	public Iterator iterator() {
		return Collections.emptyList().iterator();
	}

}