| package org.checkerframework.dataflow.cfg.node; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| |
| import com.sun.source.tree.LiteralTree; |
| import com.sun.source.tree.Tree; |
| |
| /** |
| * A node for the null literal. |
| * |
| * <pre> |
| * <em>null</em> |
| * </pre> |
| * |
| * @author Stefan Heule |
| * @author Charlie Garrett |
| * |
| */ |
| public class NullLiteralNode extends ValueLiteralNode { |
| |
| public NullLiteralNode(LiteralTree t) { |
| super(t); |
| assert t.getKind().equals(Tree.Kind.NULL_LITERAL); |
| } |
| |
| @Override |
| public Void getValue() { |
| return (Void) tree.getValue(); |
| } |
| |
| @Override |
| public <R, P> R accept(NodeVisitor<R, P> visitor, P p) { |
| return visitor.visitNullLiteral(this, p); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| // test that obj is a NullLiteralNode |
| if (obj == null || !(obj instanceof NullLiteralNode)) { |
| return false; |
| } |
| // super method compares values |
| return super.equals(obj); |
| } |
| |
| @Override |
| public Collection<Node> getOperands() { |
| return Collections.emptyList(); |
| } |
| } |