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package com.sun.org.apache.xpath.internal;

import javax.xml.transform.SourceLocator;

A class that implements this interface can construct expressions,
give information about child and parent expressions,
and give the originating source information.  A class that implements
this interface does not lay any claim to being directly executable.
Note: This interface should not be considered stable.  Only exprSetParent
and exprGetParent can be counted on to work reliably.  Work in progress.
/**
 * A class that implements this interface can construct expressions,
 * give information about child and parent expressions,
 * and give the originating source information.  A class that implements
 * this interface does not lay any claim to being directly executable.
 *
 * <p>Note: This interface should not be considered stable.  Only exprSetParent
 * and exprGetParent can be counted on to work reliably.  Work in progress.</p>
 */
public interface ExpressionNode extends SourceLocator
{
  
This pair of methods are used to inform the node of its
parent. /** This pair of methods are used to inform the node of its
    parent. */
  public void exprSetParent(ExpressionNode n);
  public ExpressionNode exprGetParent();

  
This method tells the node to add its argument to the node's
list of children.  /** This method tells the node to add its argument to the node's
    list of children.  */
  public void exprAddChild(ExpressionNode n, int i);

  
This method returns a child node.  The children are numbered
from zero, left to right. /** This method returns a child node.  The children are numbered
     from zero, left to right. */
  public ExpressionNode exprGetChild(int i);

  
Return the number of children the node has. /** Return the number of children the node has. */
  public int exprGetNumChildren();
}