From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libjava/classpath/java/util/Stack.java | 161 +++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100644 libjava/classpath/java/util/Stack.java (limited to 'libjava/classpath/java/util/Stack.java') diff --git a/libjava/classpath/java/util/Stack.java b/libjava/classpath/java/util/Stack.java new file mode 100644 index 000000000..1d8792882 --- /dev/null +++ b/libjava/classpath/java/util/Stack.java @@ -0,0 +1,161 @@ +/* Stack.java - Class that provides a Last In First Out (LIFO) + datatype, known more commonly as a Stack + Copyright (C) 1998, 1999, 2001, 2004, 2005 + Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.util; + +/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 + * "The Java Language Specification", ISBN 0-201-63451-1 + * plus online API docs for JDK 1.2 beta from http://www.javasoft.com. + * Status: Believed complete and correct + +/** + * Stack provides a Last In First Out (LIFO) data type, commonly known + * as a Stack. Stack itself extends Vector and provides the additional + * methods for stack manipulation (push, pop, peek). You can also seek for + * the 1-based position of an element on the stack. + * + * @author Warren Levy (warrenl@cygnus.com) + * @author Eric Blake (ebb9@email.byu.edu) + * @see List + * @see AbstractList + * @see LinkedList + * @since 1.0 + * @status updated to 1.4 + */ +public class Stack extends Vector +{ + // We could use Vector methods internally for the following methods, + // but have used Vector fields directly for efficiency (i.e. this + // often reduces out duplicate bounds checking). + + /** + * Compatible with JDK 1.0+. + */ + private static final long serialVersionUID = 1224463164541339165L; + + /** + * This constructor creates a new Stack, initially empty + */ + public Stack() + { + } + + /** + * Pushes an Object onto the top of the stack. This method is effectively + * the same as addElement(item). + * + * @param item the Object to push onto the stack + * @return the Object pushed onto the stack + * @see Vector#addElement(Object) + */ + public T push(T item) + { + // When growing the Stack, use the Vector routines in case more + // memory is needed. + // Note: spec indicates that this method *always* returns obj passed in! + + addElement(item); + return item; + } + + /** + * Pops an item from the stack and returns it. The item popped is + * removed from the Stack. + * + * @return the Object popped from the stack + * @throws EmptyStackException if the stack is empty + */ + @SuppressWarnings("unchecked") + public synchronized T pop() + { + if (elementCount == 0) + throw new EmptyStackException(); + + modCount++; + T obj = (T) elementData[--elementCount]; + + // Set topmost element to null to assist the gc in cleanup. + elementData[elementCount] = null; + return obj; + } + + /** + * Returns the top Object on the stack without removing it. + * + * @return the top Object on the stack + * @throws EmptyStackException if the stack is empty + */ + @SuppressWarnings("unchecked") + public synchronized T peek() + { + if (elementCount == 0) + throw new EmptyStackException(); + + return (T) elementData[elementCount - 1]; + } + + /** + * Tests if the stack is empty. + * + * @return true if the stack contains no items, false otherwise + */ + public synchronized boolean empty() + { + return elementCount == 0; + } + + /** + * Returns the position of an Object on the stack, with the top + * most Object being at position 1, and each Object deeper in the + * stack at depth + 1. + * + * @param o The object to search for + * @return The 1 based depth of the Object, or -1 if the Object + * is not on the stack + */ + public synchronized int search(Object o) + { + int i = elementCount; + while (--i >= 0) + if (equals(o, elementData[i])) + return elementCount - i; + return -1; + } +} -- cgit v1.2.3