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

Mon, 13 Dec 2010 15:11:00 -0800

author
mcimadamore
date
Mon, 13 Dec 2010 15:11:00 -0800
changeset 795
7b99f98b3035
parent 581
f2fdd52e4e87
child 798
4868a36f6fd8
permissions
-rw-r--r--

6993978: Project Coin: Compiler support of annotation to reduce varargs warnings
Reviewed-by: jjg, darcy

duke@1 1 /*
ohair@554 2 * Copyright (c) 1999, 2006, 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
duke@1 28 import java.lang.reflect.Array;
duke@1 29 import java.util.ArrayList;
duke@1 30 import java.util.Collection;
duke@1 31 import java.util.Collections;
duke@1 32 import java.util.Iterator;
duke@1 33 import java.util.AbstractCollection;
duke@1 34 import java.util.ListIterator;
duke@1 35 import java.util.NoSuchElementException;
duke@1 36
duke@1 37 /** A class for generic linked lists. Links are supposed to be
duke@1 38 * immutable, the only exception being the incremental construction of
duke@1 39 * lists via ListBuffers. List is the main container class in
duke@1 40 * GJC. Most data structures and algorthms in GJC use lists rather
duke@1 41 * than arrays.
duke@1 42 *
duke@1 43 * <p>Lists are always trailed by a sentinel element, whose head and tail
duke@1 44 * are both null.
duke@1 45 *
jjg@581 46 * <p><b>This is NOT part of any supported API.
jjg@581 47 * If you write code that depends on this, you do so at your own risk.
duke@1 48 * This code and its internal interfaces are subject to change or
duke@1 49 * deletion without notice.</b>
duke@1 50 */
duke@1 51 public class List<A> extends AbstractCollection<A> implements java.util.List<A> {
duke@1 52
duke@1 53 /** The first element of the list, supposed to be immutable.
duke@1 54 */
duke@1 55 public A head;
duke@1 56
duke@1 57 /** The remainder of the list except for its first element, supposed
duke@1 58 * to be immutable.
duke@1 59 */
duke@1 60 //@Deprecated
duke@1 61 public List<A> tail;
duke@1 62
duke@1 63 /** Construct a list given its head and tail.
duke@1 64 */
duke@1 65 List(A head, List<A> tail) {
duke@1 66 this.tail = tail;
duke@1 67 this.head = head;
duke@1 68 }
duke@1 69
duke@1 70 /** Construct an empty list.
duke@1 71 */
duke@1 72 @SuppressWarnings("unchecked")
duke@1 73 public static <A> List<A> nil() {
mcimadamore@184 74 return (List<A>)EMPTY_LIST;
duke@1 75 }
mcimadamore@184 76
mcimadamore@184 77 private static List<?> EMPTY_LIST = new List<Object>(null,null) {
duke@1 78 public List<Object> setTail(List<Object> tail) {
duke@1 79 throw new UnsupportedOperationException();
duke@1 80 }
duke@1 81 public boolean isEmpty() {
duke@1 82 return true;
duke@1 83 }
duke@1 84 };
duke@1 85
duke@1 86 /** Construct a list consisting of given element.
duke@1 87 */
duke@1 88 public static <A> List<A> of(A x1) {
duke@1 89 return new List<A>(x1, List.<A>nil());
duke@1 90 }
duke@1 91
duke@1 92 /** Construct a list consisting of given elements.
duke@1 93 */
duke@1 94 public static <A> List<A> of(A x1, A x2) {
duke@1 95 return new List<A>(x1, of(x2));
duke@1 96 }
duke@1 97
duke@1 98 /** Construct a list consisting of given elements.
duke@1 99 */
duke@1 100 public static <A> List<A> of(A x1, A x2, A x3) {
duke@1 101 return new List<A>(x1, of(x2, x3));
duke@1 102 }
duke@1 103
duke@1 104 /** Construct a list consisting of given elements.
duke@1 105 */
mcimadamore@795 106 @SuppressWarnings({"varargs", "unchecked"})
duke@1 107 public static <A> List<A> of(A x1, A x2, A x3, A... rest) {
duke@1 108 return new List<A>(x1, new List<A>(x2, new List<A>(x3, from(rest))));
duke@1 109 }
duke@1 110
duke@1 111 /**
duke@1 112 * Construct a list consisting all elements of given array.
duke@1 113 * @param array an array; if {@code null} return an empty list
duke@1 114 */
duke@1 115 public static <A> List<A> from(A[] array) {
duke@1 116 List<A> xs = nil();
duke@1 117 if (array != null)
duke@1 118 for (int i = array.length - 1; i >= 0; i--)
duke@1 119 xs = new List<A>(array[i], xs);
duke@1 120 return xs;
duke@1 121 }
duke@1 122
duke@1 123 /** Construct a list consisting of a given number of identical elements.
duke@1 124 * @param len The number of elements in the list.
duke@1 125 * @param init The value of each element.
duke@1 126 */
duke@1 127 @Deprecated
duke@1 128 public static <A> List<A> fill(int len, A init) {
duke@1 129 List<A> l = nil();
duke@1 130 for (int i = 0; i < len; i++) l = new List<A>(init, l);
duke@1 131 return l;
duke@1 132 }
duke@1 133
duke@1 134 /** Does list have no elements?
duke@1 135 */
duke@1 136 @Override
duke@1 137 public boolean isEmpty() {
duke@1 138 return tail == null;
duke@1 139 }
duke@1 140
duke@1 141 /** Does list have elements?
duke@1 142 */
duke@1 143 //@Deprecated
duke@1 144 public boolean nonEmpty() {
duke@1 145 return tail != null;
duke@1 146 }
duke@1 147
duke@1 148 /** Return the number of elements in this list.
duke@1 149 */
duke@1 150 //@Deprecated
duke@1 151 public int length() {
duke@1 152 List<A> l = this;
duke@1 153 int len = 0;
duke@1 154 while (l.tail != null) {
duke@1 155 l = l.tail;
duke@1 156 len++;
duke@1 157 }
duke@1 158 return len;
duke@1 159 }
duke@1 160 @Override
duke@1 161 public int size() {
duke@1 162 return length();
duke@1 163 }
duke@1 164
duke@1 165 public List<A> setTail(List<A> tail) {
duke@1 166 this.tail = tail;
duke@1 167 return tail;
duke@1 168 }
duke@1 169
duke@1 170 /** Prepend given element to front of list, forming and returning
duke@1 171 * a new list.
duke@1 172 */
duke@1 173 public List<A> prepend(A x) {
duke@1 174 return new List<A>(x, this);
duke@1 175 }
duke@1 176
duke@1 177 /** Prepend given list of elements to front of list, forming and returning
duke@1 178 * a new list.
duke@1 179 */
duke@1 180 public List<A> prependList(List<A> xs) {
duke@1 181 if (this.isEmpty()) return xs;
duke@1 182 if (xs.isEmpty()) return this;
duke@1 183 if (xs.tail.isEmpty()) return prepend(xs.head);
duke@1 184 // return this.prependList(xs.tail).prepend(xs.head);
duke@1 185 List<A> result = this;
duke@1 186 List<A> rev = xs.reverse();
duke@1 187 assert rev != xs;
duke@1 188 // since xs.reverse() returned a new list, we can reuse the
duke@1 189 // individual List objects, instead of allocating new ones.
duke@1 190 while (rev.nonEmpty()) {
duke@1 191 List<A> h = rev;
duke@1 192 rev = rev.tail;
duke@1 193 h.setTail(result);
duke@1 194 result = h;
duke@1 195 }
duke@1 196 return result;
duke@1 197 }
duke@1 198
duke@1 199 /** Reverse list.
duke@1 200 * If the list is empty or a singleton, then the same list is returned.
duke@1 201 * Otherwise a new list is formed.
duke@1 202 */
duke@1 203 public List<A> reverse() {
duke@1 204 // if it is empty or a singleton, return itself
duke@1 205 if (isEmpty() || tail.isEmpty())
duke@1 206 return this;
duke@1 207
duke@1 208 List<A> rev = nil();
duke@1 209 for (List<A> l = this; l.nonEmpty(); l = l.tail)
duke@1 210 rev = new List<A>(l.head, rev);
duke@1 211 return rev;
duke@1 212 }
duke@1 213
duke@1 214 /** Append given element at length, forming and returning
duke@1 215 * a new list.
duke@1 216 */
duke@1 217 public List<A> append(A x) {
duke@1 218 return of(x).prependList(this);
duke@1 219 }
duke@1 220
duke@1 221 /** Append given list at length, forming and returning
duke@1 222 * a new list.
duke@1 223 */
duke@1 224 public List<A> appendList(List<A> x) {
duke@1 225 return x.prependList(this);
duke@1 226 }
duke@1 227
duke@1 228 /**
duke@1 229 * Append given list buffer at length, forming and returning a new
duke@1 230 * list.
duke@1 231 */
duke@1 232 public List<A> appendList(ListBuffer<A> x) {
duke@1 233 return appendList(x.toList());
duke@1 234 }
duke@1 235
duke@1 236 /** Copy successive elements of this list into given vector until
duke@1 237 * list is exhausted or end of vector is reached.
duke@1 238 */
duke@1 239 @Override @SuppressWarnings("unchecked")
duke@1 240 public <T> T[] toArray(T[] vec) {
duke@1 241 int i = 0;
duke@1 242 List<A> l = this;
duke@1 243 Object[] dest = vec;
duke@1 244 while (l.nonEmpty() && i < vec.length) {
duke@1 245 dest[i] = l.head;
duke@1 246 l = l.tail;
duke@1 247 i++;
duke@1 248 }
duke@1 249 if (l.isEmpty()) {
duke@1 250 if (i < vec.length)
duke@1 251 vec[i] = null;
duke@1 252 return vec;
duke@1 253 }
duke@1 254
duke@1 255 vec = (T[])Array.newInstance(vec.getClass().getComponentType(), size());
duke@1 256 return toArray(vec);
duke@1 257 }
duke@1 258
duke@1 259 public Object[] toArray() {
duke@1 260 return toArray(new Object[size()]);
duke@1 261 }
duke@1 262
duke@1 263 /** Form a string listing all elements with given separator character.
duke@1 264 */
duke@1 265 public String toString(String sep) {
duke@1 266 if (isEmpty()) {
duke@1 267 return "";
duke@1 268 } else {
duke@1 269 StringBuffer buf = new StringBuffer();
duke@1 270 buf.append(head);
duke@1 271 for (List<A> l = tail; l.nonEmpty(); l = l.tail) {
duke@1 272 buf.append(sep);
duke@1 273 buf.append(l.head);
duke@1 274 }
duke@1 275 return buf.toString();
duke@1 276 }
duke@1 277 }
duke@1 278
duke@1 279 /** Form a string listing all elements with comma as the separator character.
duke@1 280 */
duke@1 281 @Override
duke@1 282 public String toString() {
duke@1 283 return toString(",");
duke@1 284 }
duke@1 285
duke@1 286 /** Compute a hash code, overrides Object
duke@1 287 * @see java.util.List#hashCode
duke@1 288 */
duke@1 289 @Override
duke@1 290 public int hashCode() {
duke@1 291 List<A> l = this;
duke@1 292 int h = 1;
duke@1 293 while (l.tail != null) {
duke@1 294 h = h * 31 + (l.head == null ? 0 : l.head.hashCode());
duke@1 295 l = l.tail;
duke@1 296 }
duke@1 297 return h;
duke@1 298 }
duke@1 299
duke@1 300 /** Is this list the same as other list?
duke@1 301 * @see java.util.List#equals
duke@1 302 */
duke@1 303 @Override
duke@1 304 public boolean equals(Object other) {
duke@1 305 if (other instanceof List<?>)
duke@1 306 return equals(this, (List<?>)other);
duke@1 307 if (other instanceof java.util.List<?>) {
duke@1 308 List<A> t = this;
duke@1 309 Iterator<?> oIter = ((java.util.List<?>) other).iterator();
duke@1 310 while (t.tail != null && oIter.hasNext()) {
duke@1 311 Object o = oIter.next();
duke@1 312 if ( !(t.head == null ? o == null : t.head.equals(o)))
duke@1 313 return false;
duke@1 314 t = t.tail;
duke@1 315 }
duke@1 316 return (t.isEmpty() && !oIter.hasNext());
duke@1 317 }
duke@1 318 return false;
duke@1 319 }
duke@1 320
duke@1 321 /** Are the two lists the same?
duke@1 322 */
mcimadamore@184 323 public static boolean equals(List<?> xs, List<?> ys) {
duke@1 324 while (xs.tail != null && ys.tail != null) {
duke@1 325 if (xs.head == null) {
duke@1 326 if (ys.head != null) return false;
duke@1 327 } else {
duke@1 328 if (!xs.head.equals(ys.head)) return false;
duke@1 329 }
duke@1 330 xs = xs.tail;
duke@1 331 ys = ys.tail;
duke@1 332 }
duke@1 333 return xs.tail == null && ys.tail == null;
duke@1 334 }
duke@1 335
duke@1 336 /** Does the list contain the specified element?
duke@1 337 */
duke@1 338 @Override
duke@1 339 public boolean contains(Object x) {
duke@1 340 List<A> l = this;
duke@1 341 while (l.tail != null) {
duke@1 342 if (x == null) {
duke@1 343 if (l.head == null) return true;
duke@1 344 } else {
duke@1 345 if (l.head.equals(x)) return true;
duke@1 346 }
duke@1 347 l = l.tail;
duke@1 348 }
duke@1 349 return false;
duke@1 350 }
duke@1 351
duke@1 352 /** The last element in the list, if any, or null.
duke@1 353 */
duke@1 354 public A last() {
duke@1 355 A last = null;
duke@1 356 List<A> t = this;
duke@1 357 while (t.tail != null) {
duke@1 358 last = t.head;
duke@1 359 t = t.tail;
duke@1 360 }
duke@1 361 return last;
duke@1 362 }
duke@1 363
duke@1 364 @SuppressWarnings("unchecked")
duke@1 365 public static <T> List<T> convert(Class<T> klass, List<?> list) {
duke@1 366 if (list == null)
duke@1 367 return null;
duke@1 368 for (Object o : list)
duke@1 369 klass.cast(o);
duke@1 370 return (List<T>)list;
duke@1 371 }
duke@1 372
mcimadamore@184 373 private static Iterator<?> EMPTYITERATOR = new Iterator<Object>() {
duke@1 374 public boolean hasNext() {
duke@1 375 return false;
duke@1 376 }
duke@1 377 public Object next() {
duke@1 378 throw new java.util.NoSuchElementException();
duke@1 379 }
duke@1 380 public void remove() {
duke@1 381 throw new UnsupportedOperationException();
duke@1 382 }
duke@1 383 };
duke@1 384
duke@1 385 @SuppressWarnings("unchecked")
duke@1 386 private static <A> Iterator<A> emptyIterator() {
mcimadamore@184 387 return (Iterator<A>)EMPTYITERATOR;
duke@1 388 }
duke@1 389
duke@1 390 @Override
duke@1 391 public Iterator<A> iterator() {
duke@1 392 if (tail == null)
duke@1 393 return emptyIterator();
duke@1 394 return new Iterator<A>() {
duke@1 395 List<A> elems = List.this;
duke@1 396 public boolean hasNext() {
duke@1 397 return elems.tail != null;
duke@1 398 }
duke@1 399 public A next() {
duke@1 400 if (elems.tail == null)
duke@1 401 throw new NoSuchElementException();
duke@1 402 A result = elems.head;
duke@1 403 elems = elems.tail;
duke@1 404 return result;
duke@1 405 }
duke@1 406 public void remove() {
duke@1 407 throw new UnsupportedOperationException();
duke@1 408 }
duke@1 409 };
duke@1 410 }
duke@1 411
duke@1 412 public A get(int index) {
duke@1 413 if (index < 0)
duke@1 414 throw new IndexOutOfBoundsException(String.valueOf(index));
duke@1 415
duke@1 416 List<A> l = this;
duke@1 417 for (int i = index; i-- > 0 && !l.isEmpty(); l = l.tail)
duke@1 418 ;
duke@1 419
duke@1 420 if (l.isEmpty())
duke@1 421 throw new IndexOutOfBoundsException("Index: " + index + ", " +
duke@1 422 "Size: " + size());
duke@1 423 return l.head;
duke@1 424 }
duke@1 425
duke@1 426 public boolean addAll(int index, Collection<? extends A> c) {
duke@1 427 if (c.isEmpty())
duke@1 428 return false;
duke@1 429 throw new UnsupportedOperationException();
duke@1 430 }
duke@1 431
duke@1 432 public A set(int index, A element) {
duke@1 433 throw new UnsupportedOperationException();
duke@1 434 }
duke@1 435
duke@1 436 public void add(int index, A element) {
duke@1 437 throw new UnsupportedOperationException();
duke@1 438 }
duke@1 439
duke@1 440 public A remove(int index) {
duke@1 441 throw new UnsupportedOperationException();
duke@1 442 }
duke@1 443
duke@1 444 public int indexOf(Object o) {
duke@1 445 int i = 0;
duke@1 446 for (List<A> l = this; l.tail != null; l = l.tail, i++) {
duke@1 447 if (l.head == null ? o == null : l.head.equals(o))
duke@1 448 return i;
duke@1 449 }
duke@1 450 return -1;
duke@1 451 }
duke@1 452
duke@1 453 public int lastIndexOf(Object o) {
duke@1 454 int last = -1;
duke@1 455 int i = 0;
duke@1 456 for (List<A> l = this; l.tail != null; l = l.tail, i++) {
duke@1 457 if (l.head == null ? o == null : l.head.equals(o))
duke@1 458 last = i;
duke@1 459 }
duke@1 460 return last;
duke@1 461 }
duke@1 462
duke@1 463 public ListIterator<A> listIterator() {
duke@1 464 return Collections.unmodifiableList(new ArrayList<A>(this)).listIterator();
duke@1 465 }
duke@1 466
duke@1 467 public ListIterator<A> listIterator(int index) {
duke@1 468 return Collections.unmodifiableList(new ArrayList<A>(this)).listIterator(index);
duke@1 469 }
duke@1 470
duke@1 471 public java.util.List<A> subList(int fromIndex, int toIndex) {
duke@1 472 if (fromIndex < 0 || toIndex > size() || fromIndex > toIndex)
duke@1 473 throw new IllegalArgumentException();
duke@1 474
duke@1 475 ArrayList<A> a = new ArrayList<A>(toIndex - fromIndex);
duke@1 476 int i = 0;
duke@1 477 for (List<A> l = this; l.tail != null; l = l.tail, i++) {
duke@1 478 if (i == toIndex)
duke@1 479 break;
duke@1 480 if (i >= fromIndex)
duke@1 481 a.add(l.head);
duke@1 482 }
duke@1 483
duke@1 484 return Collections.unmodifiableList(a);
duke@1 485 }
duke@1 486 }

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