| /* |
| * Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.tools.jstat; |
| |
| /** |
| * A class that represents a mathematical expression as a tree structure |
| * containing operators as interior nodes and operands as leaves. The |
| * operands can be literals or lazily bound variables. |
| * |
| * @author Brian Doherty |
| * @since 1.5 |
| */ |
| public class Expression { |
| private static int nextOrdinal; |
| private boolean debug = Boolean.getBoolean("Expression.debug"); |
| private Expression left; |
| private Expression right; |
| private Operator operator; |
| private int ordinal = nextOrdinal++; |
| |
| Expression() { |
| if (debug) { |
| System.out.println("Expression " + ordinal + " created"); |
| } |
| } |
| |
| void setLeft(Expression left) { |
| if (debug) { |
| System.out.println("Setting left on " + ordinal + " to " + left); |
| } |
| this.left = left; |
| } |
| |
| Expression getLeft() { |
| return left; |
| } |
| |
| void setRight(Expression right) { |
| if (debug) { |
| System.out.println("Setting right on " + ordinal + " to " + right); |
| } |
| this.right = right; |
| } |
| |
| Expression getRight() { |
| return right; |
| } |
| |
| void setOperator(Operator o) { |
| if (debug) { |
| System.out.println("Setting operator on " + ordinal + " to " + o); |
| } |
| this.operator = o; |
| } |
| |
| Operator getOperator() { |
| return operator; |
| } |
| |
| public String toString() { |
| StringBuilder b = new StringBuilder(); |
| b.append('('); |
| if (left != null) { |
| b.append(left.toString()); |
| } |
| if (operator != null) { |
| b.append(operator.toString()); |
| if (right != null) { |
| b.append(right.toString()); |
| } |
| } |
| b.append(')'); |
| return b.toString(); |
| } |
| } |