//==============================================================================
// CodeGeneratingVisitor.java
//==============================================================================

package sample.visitor;

/**
* Responsibilities:<ul>
* <li>visits the nodes of a program AST,</li>
* <li>generates code appropriate to each kind of AST node.</li>
* </ul><p></p>
* 
* @author Copyright 2003 Nikolas S. Boyd.
*/
public class CodeGeneratingVisitor 
implements Node.Visitor,
AssignmentNode.Visitor, 
VariableReferenceNode.Visitor
// ... other kinds of AST node Visitors 
{

	/**
	* Visits an AST <tt>node</tt> and generates code appropriate to the specific
	* kind of node.
	* @param node a node in a program AST. 
	*/
	public void visit(Node node) {
		// this method should never be called in practice 
		// it's here only to satisfy the selective visitor pattern
		return;
	}

	/**
	* Visits an AST <tt>node</tt> and generates code appropriate to the specific
	* kind of node.
	* @param node a node in a program AST. 
	*/
	public void visit(AssignmentNode node) {
		// ... assignment node code generation
		return;
	}

	/**
	* Visits an AST <tt>node</tt> and generates code appropriate to the specific
	* kind of node.
	* @param node a node in a program AST. 
	*/
	public void visit(VariableReferenceNode node) {
		// ... variable reference node processing
		return;
	}

	// ... visit() methods for each of the other kinds of node Visitors ...

} // CodeGeneratingVisitor