--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/tools/jstat/Expression.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2004 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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();
+ }
+}