org.eclipse.jdt.ui/core refactoring/org/eclipse/jdt/internal/corext/refactoring/typeconstraints/types/NullType.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.refactoring.typeconstraints.types;


public final class NullType extends TType {

	protected NullType(TypeEnvironment environment) {
		super(environment, "N"); //$NON-NLS-1$
	}

	public int getKind() {
		return NULL_TYPE;
	}

	public TType[] getSubTypes() {
		throw new UnsupportedOperationException();
	}
	
	protected boolean doEquals(TType type) {
		return true;
	}

	public String getName() {
		return "null";  //$NON-NLS-1$
	}
	
	protected String getPlainPrettySignature() {
		return getName();
	}
	
	protected boolean doCanAssignTo(TType lhs) {
		int kind= lhs.getKind();
		return kind != PRIMITIVE_TYPE && kind != VOID_TYPE;
	}
}