src/share/classes/com/sun/tools/javac/util/ListBuffer.java

Mon, 10 Jan 2011 15:08:31 -0800

author
jjg
date
Mon, 10 Jan 2011 15:08:31 -0800
changeset 816
7c537f4298fb
parent 581
f2fdd52e4e87
child 1444
170e486632d9
permissions
-rw-r--r--

6396503: javac should not require assertions enabled
Reviewed-by: mcimadamore

duke@1 1 /*
ohair@554 2 * Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.
duke@1 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1 4 *
duke@1 5 * This code is free software; you can redistribute it and/or modify it
duke@1 6 * under the terms of the GNU General Public License version 2 only, as
ohair@554 7 * published by the Free Software Foundation. Oracle designates this
duke@1 8 * particular file as subject to the "Classpath" exception as provided
ohair@554 9 * by Oracle in the LICENSE file that accompanied this code.
duke@1 10 *
duke@1 11 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@1 14 * version 2 for more details (a copy is included in the LICENSE file that
duke@1 15 * accompanied this code).
duke@1 16 *
duke@1 17 * You should have received a copy of the GNU General Public License version
duke@1 18 * 2 along with this work; if not, write to the Free Software Foundation,
duke@1 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1 20 *
ohair@554 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554 22 * or visit www.oracle.com if you need additional information or have any
ohair@554 23 * questions.
duke@1 24 */
duke@1 25
duke@1 26 package com.sun.tools.javac.util;
duke@1 27
jjg@70 28 import java.util.AbstractQueue;
duke@1 29 import java.util.Collection;
duke@1 30 import java.util.Iterator;
duke@1 31 import java.util.NoSuchElementException;
duke@1 32
duke@1 33 /** A class for constructing lists by appending elements. Modelled after
duke@1 34 * java.lang.StringBuffer.
duke@1 35 *
jjg@581 36 * <p><b>This is NOT part of any supported API.
jjg@581 37 * If you write code that depends on this, you do so at your own risk.
duke@1 38 * This code and its internal interfaces are subject to change or
duke@1 39 * deletion without notice.</b>
duke@1 40 */
jjg@70 41 public class ListBuffer<A> extends AbstractQueue<A> {
duke@1 42
duke@1 43 public static <T> ListBuffer<T> lb() {
duke@1 44 return new ListBuffer<T>();
duke@1 45 }
duke@1 46
jjg@70 47 public static <T> ListBuffer<T> of(T x) {
jjg@70 48 ListBuffer<T> lb = new ListBuffer<T>();
jjg@70 49 lb.add(x);
jjg@70 50 return lb;
jjg@70 51 }
jjg@70 52
duke@1 53 /** The list of elements of this buffer.
duke@1 54 */
duke@1 55 public List<A> elems;
duke@1 56
duke@1 57 /** A pointer pointing to the last, sentinel element of `elems'.
duke@1 58 */
duke@1 59 public List<A> last;
duke@1 60
duke@1 61 /** The number of element in this buffer.
duke@1 62 */
duke@1 63 public int count;
duke@1 64
duke@1 65 /** Has a list been created from this buffer yet?
duke@1 66 */
duke@1 67 public boolean shared;
duke@1 68
duke@1 69 /** Create a new initially empty list buffer.
duke@1 70 */
duke@1 71 public ListBuffer() {
duke@1 72 clear();
duke@1 73 }
duke@1 74
duke@1 75 public final void clear() {
duke@1 76 this.elems = new List<A>(null,null);
duke@1 77 this.last = this.elems;
duke@1 78 count = 0;
duke@1 79 shared = false;
duke@1 80 }
duke@1 81
duke@1 82 /** Return the number of elements in this buffer.
duke@1 83 */
duke@1 84 public int length() {
duke@1 85 return count;
duke@1 86 }
duke@1 87 public int size() {
duke@1 88 return count;
duke@1 89 }
duke@1 90
duke@1 91 /** Is buffer empty?
duke@1 92 */
duke@1 93 public boolean isEmpty() {
duke@1 94 return count == 0;
duke@1 95 }
duke@1 96
duke@1 97 /** Is buffer not empty?
duke@1 98 */
duke@1 99 public boolean nonEmpty() {
duke@1 100 return count != 0;
duke@1 101 }
duke@1 102
duke@1 103 /** Copy list and sets last.
duke@1 104 */
duke@1 105 private void copy() {
duke@1 106 List<A> p = elems = new List<A>(elems.head, elems.tail);
duke@1 107 while (true) {
duke@1 108 List<A> tail = p.tail;
duke@1 109 if (tail == null) break;
duke@1 110 tail = new List<A>(tail.head, tail.tail);
duke@1 111 p.setTail(tail);
duke@1 112 p = tail;
duke@1 113 }
duke@1 114 last = p;
duke@1 115 shared = false;
duke@1 116 }
duke@1 117
duke@1 118 /** Prepend an element to buffer.
duke@1 119 */
duke@1 120 public ListBuffer<A> prepend(A x) {
duke@1 121 elems = elems.prepend(x);
duke@1 122 count++;
duke@1 123 return this;
duke@1 124 }
duke@1 125
duke@1 126 /** Append an element to buffer.
duke@1 127 */
duke@1 128 public ListBuffer<A> append(A x) {
jjg@70 129 x.getClass(); // null check
duke@1 130 if (shared) copy();
duke@1 131 last.head = x;
duke@1 132 last.setTail(new List<A>(null,null));
duke@1 133 last = last.tail;
duke@1 134 count++;
duke@1 135 return this;
duke@1 136 }
duke@1 137
duke@1 138 /** Append all elements in a list to buffer.
duke@1 139 */
duke@1 140 public ListBuffer<A> appendList(List<A> xs) {
duke@1 141 while (xs.nonEmpty()) {
duke@1 142 append(xs.head);
duke@1 143 xs = xs.tail;
duke@1 144 }
duke@1 145 return this;
duke@1 146 }
duke@1 147
duke@1 148 /** Append all elements in a list to buffer.
duke@1 149 */
duke@1 150 public ListBuffer<A> appendList(ListBuffer<A> xs) {
duke@1 151 return appendList(xs.toList());
duke@1 152 }
duke@1 153
duke@1 154 /** Append all elements in an array to buffer.
duke@1 155 */
duke@1 156 public ListBuffer<A> appendArray(A[] xs) {
duke@1 157 for (int i = 0; i < xs.length; i++) {
duke@1 158 append(xs[i]);
duke@1 159 }
duke@1 160 return this;
duke@1 161 }
duke@1 162
duke@1 163 /** Convert buffer to a list of all its elements.
duke@1 164 */
duke@1 165 public List<A> toList() {
duke@1 166 shared = true;
duke@1 167 return elems;
duke@1 168 }
duke@1 169
duke@1 170 /** Does the list contain the specified element?
duke@1 171 */
duke@1 172 public boolean contains(Object x) {
duke@1 173 return elems.contains(x);
duke@1 174 }
duke@1 175
duke@1 176 /** Convert buffer to an array
duke@1 177 */
duke@1 178 public <T> T[] toArray(T[] vec) {
duke@1 179 return elems.toArray(vec);
duke@1 180 }
duke@1 181 public Object[] toArray() {
duke@1 182 return toArray(new Object[size()]);
duke@1 183 }
duke@1 184
duke@1 185 /** The first element in this buffer.
duke@1 186 */
duke@1 187 public A first() {
duke@1 188 return elems.head;
duke@1 189 }
duke@1 190
jjg@70 191 /** Return first element in this buffer and remove
duke@1 192 */
jjg@70 193 public A next() {
jjg@70 194 A x = elems.head;
duke@1 195 if (elems != last) {
duke@1 196 elems = elems.tail;
duke@1 197 count--;
duke@1 198 }
duke@1 199 return x;
duke@1 200 }
duke@1 201
duke@1 202 /** An enumeration of all elements in this buffer.
duke@1 203 */
duke@1 204 public Iterator<A> iterator() {
duke@1 205 return new Iterator<A>() {
duke@1 206 List<A> elems = ListBuffer.this.elems;
duke@1 207 public boolean hasNext() {
duke@1 208 return elems != last;
duke@1 209 }
duke@1 210 public A next() {
duke@1 211 if (elems == last)
duke@1 212 throw new NoSuchElementException();
duke@1 213 A elem = elems.head;
duke@1 214 elems = elems.tail;
duke@1 215 return elem;
duke@1 216 }
duke@1 217 public void remove() {
duke@1 218 throw new UnsupportedOperationException();
duke@1 219 }
duke@1 220 };
duke@1 221 }
duke@1 222
duke@1 223 public boolean add(A a) {
jjg@70 224 append(a);
jjg@70 225 return true;
duke@1 226 }
jjg@70 227
duke@1 228 public boolean remove(Object o) {
duke@1 229 throw new UnsupportedOperationException();
duke@1 230 }
jjg@70 231
duke@1 232 public boolean containsAll(Collection<?> c) {
jjg@70 233 for (Object x: c) {
jjg@70 234 if (!contains(x))
jjg@70 235 return false;
jjg@70 236 }
jjg@70 237 return true;
duke@1 238 }
jjg@70 239
duke@1 240 public boolean addAll(Collection<? extends A> c) {
jjg@70 241 for (A a: c)
jjg@70 242 append(a);
jjg@70 243 return true;
duke@1 244 }
jjg@70 245
duke@1 246 public boolean removeAll(Collection<?> c) {
duke@1 247 throw new UnsupportedOperationException();
duke@1 248 }
jjg@70 249
duke@1 250 public boolean retainAll(Collection<?> c) {
duke@1 251 throw new UnsupportedOperationException();
duke@1 252 }
jjg@70 253
jjg@70 254 public boolean offer(A a) {
jjg@70 255 append(a);
jjg@70 256 return true;
jjg@70 257 }
jjg@70 258
jjg@70 259 public A poll() {
jjg@70 260 return next();
jjg@70 261 }
jjg@70 262
jjg@70 263 public A peek() {
jjg@70 264 return first();
jjg@70 265 }
duke@1 266 }

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