ExpressionObject.java #2

/*
 * ExpressionObject.java 1.0
 *
 *
 * June 23, 2000
 *
 * @see openjava.ptree.ParseTree
 * @version 1.0 last updated:  June 23, 2000
 * @author  Michiaki Tatsubori
 */
package openjava.ptree;


import openjava.ptree.util.*;
import openjava.mop.*;
import java.io.OutputStream;



/**
 * The Expression interface presents common interface
 * to access Expression node of parse tree
 *
 * this interface is implements by
 * <pre>
 *   UnaryExpression
 *   BinaryExpression
 *   ConditionalExpression
 *   AssignmentExpression
 *   CastExpression
 *   AllocationExpression
 *   ArrayAllocationExpression
 *   Variable
 *   MethodCall
 *   SpecialName
 *   Literal
 *   ClassLiteral
 *   ArrayAccess
 *   FieldAccess
 * </pre>
 *
 * @see openjava.ptree.ParseTree
 * @see openjava.ptree.NonLeaf
 */
public abstract class ExpressionObject extends NonLeaf
    implements Expression
{
    private OJClass cachedType = null;

    void soilCache() {
	cachedType = null;
	ParseTree parent = getParent();
	if (parent instanceof ExpressionObject) {
	    ExpressionObject pexp = (ExpressionObject) parent;
	    pexp.soilCache();
	}
    }

    /**
     * dirty implementation
     */
    public OJClass getCachedType(Environment env) throws Exception {
	if (cachedType == null)  cachedType = getType(env);
	return cachedType;
    }

    public abstract OJClass getType(Environment env, boolean using_cache)
	throws Exception;

    public abstract OJClass getType(Environment env)
	throws Exception;

    /**
     * Makes this ptree a list presenting for
     * [ p ]
     *
     * @param  p  list's element
     */
    protected void set( Object[] ptrees )  {
	soilCache();
	super.set(ptrees);
    }

}