Tue, 13 Oct 2009 15:26:30 -0700
6891079: Compiler allows invalid binary literals 0b and oBL
Reviewed-by: darcy
duke@1 | 1 | /* |
duke@1 | 2 | * Copyright 1999-2006 Sun Microsystems, Inc. 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 |
duke@1 | 7 | * published by the Free Software Foundation. Sun designates this |
duke@1 | 8 | * particular file as subject to the "Classpath" exception as provided |
duke@1 | 9 | * by Sun 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 | * |
duke@1 | 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@1 | 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@1 | 23 | * have any 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 | * |
duke@1 | 46 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
duke@1 | 47 | * 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 | */ |
duke@1 | 106 | public static <A> List<A> of(A x1, A x2, A x3, A... rest) { |
duke@1 | 107 | return new List<A>(x1, new List<A>(x2, new List<A>(x3, from(rest)))); |
duke@1 | 108 | } |
duke@1 | 109 | |
duke@1 | 110 | /** |
duke@1 | 111 | * Construct a list consisting all elements of given array. |
duke@1 | 112 | * @param array an array; if {@code null} return an empty list |
duke@1 | 113 | */ |
duke@1 | 114 | public static <A> List<A> from(A[] array) { |
duke@1 | 115 | List<A> xs = nil(); |
duke@1 | 116 | if (array != null) |
duke@1 | 117 | for (int i = array.length - 1; i >= 0; i--) |
duke@1 | 118 | xs = new List<A>(array[i], xs); |
duke@1 | 119 | return xs; |
duke@1 | 120 | } |
duke@1 | 121 | |
duke@1 | 122 | /** Construct a list consisting of a given number of identical elements. |
duke@1 | 123 | * @param len The number of elements in the list. |
duke@1 | 124 | * @param init The value of each element. |
duke@1 | 125 | */ |
duke@1 | 126 | @Deprecated |
duke@1 | 127 | public static <A> List<A> fill(int len, A init) { |
duke@1 | 128 | List<A> l = nil(); |
duke@1 | 129 | for (int i = 0; i < len; i++) l = new List<A>(init, l); |
duke@1 | 130 | return l; |
duke@1 | 131 | } |
duke@1 | 132 | |
duke@1 | 133 | /** Does list have no elements? |
duke@1 | 134 | */ |
duke@1 | 135 | @Override |
duke@1 | 136 | public boolean isEmpty() { |
duke@1 | 137 | return tail == null; |
duke@1 | 138 | } |
duke@1 | 139 | |
duke@1 | 140 | /** Does list have elements? |
duke@1 | 141 | */ |
duke@1 | 142 | //@Deprecated |
duke@1 | 143 | public boolean nonEmpty() { |
duke@1 | 144 | return tail != null; |
duke@1 | 145 | } |
duke@1 | 146 | |
duke@1 | 147 | /** Return the number of elements in this list. |
duke@1 | 148 | */ |
duke@1 | 149 | //@Deprecated |
duke@1 | 150 | public int length() { |
duke@1 | 151 | List<A> l = this; |
duke@1 | 152 | int len = 0; |
duke@1 | 153 | while (l.tail != null) { |
duke@1 | 154 | l = l.tail; |
duke@1 | 155 | len++; |
duke@1 | 156 | } |
duke@1 | 157 | return len; |
duke@1 | 158 | } |
duke@1 | 159 | @Override |
duke@1 | 160 | public int size() { |
duke@1 | 161 | return length(); |
duke@1 | 162 | } |
duke@1 | 163 | |
duke@1 | 164 | public List<A> setTail(List<A> tail) { |
duke@1 | 165 | this.tail = tail; |
duke@1 | 166 | return tail; |
duke@1 | 167 | } |
duke@1 | 168 | |
duke@1 | 169 | /** Prepend given element to front of list, forming and returning |
duke@1 | 170 | * a new list. |
duke@1 | 171 | */ |
duke@1 | 172 | public List<A> prepend(A x) { |
duke@1 | 173 | return new List<A>(x, this); |
duke@1 | 174 | } |
duke@1 | 175 | |
duke@1 | 176 | /** Prepend given list of elements to front of list, forming and returning |
duke@1 | 177 | * a new list. |
duke@1 | 178 | */ |
duke@1 | 179 | public List<A> prependList(List<A> xs) { |
duke@1 | 180 | if (this.isEmpty()) return xs; |
duke@1 | 181 | if (xs.isEmpty()) return this; |
duke@1 | 182 | if (xs.tail.isEmpty()) return prepend(xs.head); |
duke@1 | 183 | // return this.prependList(xs.tail).prepend(xs.head); |
duke@1 | 184 | List<A> result = this; |
duke@1 | 185 | List<A> rev = xs.reverse(); |
duke@1 | 186 | assert rev != xs; |
duke@1 | 187 | // since xs.reverse() returned a new list, we can reuse the |
duke@1 | 188 | // individual List objects, instead of allocating new ones. |
duke@1 | 189 | while (rev.nonEmpty()) { |
duke@1 | 190 | List<A> h = rev; |
duke@1 | 191 | rev = rev.tail; |
duke@1 | 192 | h.setTail(result); |
duke@1 | 193 | result = h; |
duke@1 | 194 | } |
duke@1 | 195 | return result; |
duke@1 | 196 | } |
duke@1 | 197 | |
duke@1 | 198 | /** Reverse list. |
duke@1 | 199 | * If the list is empty or a singleton, then the same list is returned. |
duke@1 | 200 | * Otherwise a new list is formed. |
duke@1 | 201 | */ |
duke@1 | 202 | public List<A> reverse() { |
duke@1 | 203 | // if it is empty or a singleton, return itself |
duke@1 | 204 | if (isEmpty() || tail.isEmpty()) |
duke@1 | 205 | return this; |
duke@1 | 206 | |
duke@1 | 207 | List<A> rev = nil(); |
duke@1 | 208 | for (List<A> l = this; l.nonEmpty(); l = l.tail) |
duke@1 | 209 | rev = new List<A>(l.head, rev); |
duke@1 | 210 | return rev; |
duke@1 | 211 | } |
duke@1 | 212 | |
duke@1 | 213 | /** Append given element at length, forming and returning |
duke@1 | 214 | * a new list. |
duke@1 | 215 | */ |
duke@1 | 216 | public List<A> append(A x) { |
duke@1 | 217 | return of(x).prependList(this); |
duke@1 | 218 | } |
duke@1 | 219 | |
duke@1 | 220 | /** Append given list at length, forming and returning |
duke@1 | 221 | * a new list. |
duke@1 | 222 | */ |
duke@1 | 223 | public List<A> appendList(List<A> x) { |
duke@1 | 224 | return x.prependList(this); |
duke@1 | 225 | } |
duke@1 | 226 | |
duke@1 | 227 | /** |
duke@1 | 228 | * Append given list buffer at length, forming and returning a new |
duke@1 | 229 | * list. |
duke@1 | 230 | */ |
duke@1 | 231 | public List<A> appendList(ListBuffer<A> x) { |
duke@1 | 232 | return appendList(x.toList()); |
duke@1 | 233 | } |
duke@1 | 234 | |
duke@1 | 235 | /** Copy successive elements of this list into given vector until |
duke@1 | 236 | * list is exhausted or end of vector is reached. |
duke@1 | 237 | */ |
duke@1 | 238 | @Override @SuppressWarnings("unchecked") |
duke@1 | 239 | public <T> T[] toArray(T[] vec) { |
duke@1 | 240 | int i = 0; |
duke@1 | 241 | List<A> l = this; |
duke@1 | 242 | Object[] dest = vec; |
duke@1 | 243 | while (l.nonEmpty() && i < vec.length) { |
duke@1 | 244 | dest[i] = l.head; |
duke@1 | 245 | l = l.tail; |
duke@1 | 246 | i++; |
duke@1 | 247 | } |
duke@1 | 248 | if (l.isEmpty()) { |
duke@1 | 249 | if (i < vec.length) |
duke@1 | 250 | vec[i] = null; |
duke@1 | 251 | return vec; |
duke@1 | 252 | } |
duke@1 | 253 | |
duke@1 | 254 | vec = (T[])Array.newInstance(vec.getClass().getComponentType(), size()); |
duke@1 | 255 | return toArray(vec); |
duke@1 | 256 | } |
duke@1 | 257 | |
duke@1 | 258 | public Object[] toArray() { |
duke@1 | 259 | return toArray(new Object[size()]); |
duke@1 | 260 | } |
duke@1 | 261 | |
duke@1 | 262 | /** Form a string listing all elements with given separator character. |
duke@1 | 263 | */ |
duke@1 | 264 | public String toString(String sep) { |
duke@1 | 265 | if (isEmpty()) { |
duke@1 | 266 | return ""; |
duke@1 | 267 | } else { |
duke@1 | 268 | StringBuffer buf = new StringBuffer(); |
duke@1 | 269 | buf.append(head); |
duke@1 | 270 | for (List<A> l = tail; l.nonEmpty(); l = l.tail) { |
duke@1 | 271 | buf.append(sep); |
duke@1 | 272 | buf.append(l.head); |
duke@1 | 273 | } |
duke@1 | 274 | return buf.toString(); |
duke@1 | 275 | } |
duke@1 | 276 | } |
duke@1 | 277 | |
duke@1 | 278 | /** Form a string listing all elements with comma as the separator character. |
duke@1 | 279 | */ |
duke@1 | 280 | @Override |
duke@1 | 281 | public String toString() { |
duke@1 | 282 | return toString(","); |
duke@1 | 283 | } |
duke@1 | 284 | |
duke@1 | 285 | /** Compute a hash code, overrides Object |
duke@1 | 286 | * @see java.util.List#hashCode |
duke@1 | 287 | */ |
duke@1 | 288 | @Override |
duke@1 | 289 | public int hashCode() { |
duke@1 | 290 | List<A> l = this; |
duke@1 | 291 | int h = 1; |
duke@1 | 292 | while (l.tail != null) { |
duke@1 | 293 | h = h * 31 + (l.head == null ? 0 : l.head.hashCode()); |
duke@1 | 294 | l = l.tail; |
duke@1 | 295 | } |
duke@1 | 296 | return h; |
duke@1 | 297 | } |
duke@1 | 298 | |
duke@1 | 299 | /** Is this list the same as other list? |
duke@1 | 300 | * @see java.util.List#equals |
duke@1 | 301 | */ |
duke@1 | 302 | @Override |
duke@1 | 303 | public boolean equals(Object other) { |
duke@1 | 304 | if (other instanceof List<?>) |
duke@1 | 305 | return equals(this, (List<?>)other); |
duke@1 | 306 | if (other instanceof java.util.List<?>) { |
duke@1 | 307 | List<A> t = this; |
duke@1 | 308 | Iterator<?> oIter = ((java.util.List<?>) other).iterator(); |
duke@1 | 309 | while (t.tail != null && oIter.hasNext()) { |
duke@1 | 310 | Object o = oIter.next(); |
duke@1 | 311 | if ( !(t.head == null ? o == null : t.head.equals(o))) |
duke@1 | 312 | return false; |
duke@1 | 313 | t = t.tail; |
duke@1 | 314 | } |
duke@1 | 315 | return (t.isEmpty() && !oIter.hasNext()); |
duke@1 | 316 | } |
duke@1 | 317 | return false; |
duke@1 | 318 | } |
duke@1 | 319 | |
duke@1 | 320 | /** Are the two lists the same? |
duke@1 | 321 | */ |
mcimadamore@184 | 322 | public static boolean equals(List<?> xs, List<?> ys) { |
duke@1 | 323 | while (xs.tail != null && ys.tail != null) { |
duke@1 | 324 | if (xs.head == null) { |
duke@1 | 325 | if (ys.head != null) return false; |
duke@1 | 326 | } else { |
duke@1 | 327 | if (!xs.head.equals(ys.head)) return false; |
duke@1 | 328 | } |
duke@1 | 329 | xs = xs.tail; |
duke@1 | 330 | ys = ys.tail; |
duke@1 | 331 | } |
duke@1 | 332 | return xs.tail == null && ys.tail == null; |
duke@1 | 333 | } |
duke@1 | 334 | |
duke@1 | 335 | /** Does the list contain the specified element? |
duke@1 | 336 | */ |
duke@1 | 337 | @Override |
duke@1 | 338 | public boolean contains(Object x) { |
duke@1 | 339 | List<A> l = this; |
duke@1 | 340 | while (l.tail != null) { |
duke@1 | 341 | if (x == null) { |
duke@1 | 342 | if (l.head == null) return true; |
duke@1 | 343 | } else { |
duke@1 | 344 | if (l.head.equals(x)) return true; |
duke@1 | 345 | } |
duke@1 | 346 | l = l.tail; |
duke@1 | 347 | } |
duke@1 | 348 | return false; |
duke@1 | 349 | } |
duke@1 | 350 | |
duke@1 | 351 | /** The last element in the list, if any, or null. |
duke@1 | 352 | */ |
duke@1 | 353 | public A last() { |
duke@1 | 354 | A last = null; |
duke@1 | 355 | List<A> t = this; |
duke@1 | 356 | while (t.tail != null) { |
duke@1 | 357 | last = t.head; |
duke@1 | 358 | t = t.tail; |
duke@1 | 359 | } |
duke@1 | 360 | return last; |
duke@1 | 361 | } |
duke@1 | 362 | |
duke@1 | 363 | @SuppressWarnings("unchecked") |
duke@1 | 364 | public static <T> List<T> convert(Class<T> klass, List<?> list) { |
duke@1 | 365 | if (list == null) |
duke@1 | 366 | return null; |
duke@1 | 367 | for (Object o : list) |
duke@1 | 368 | klass.cast(o); |
duke@1 | 369 | return (List<T>)list; |
duke@1 | 370 | } |
duke@1 | 371 | |
mcimadamore@184 | 372 | private static Iterator<?> EMPTYITERATOR = new Iterator<Object>() { |
duke@1 | 373 | public boolean hasNext() { |
duke@1 | 374 | return false; |
duke@1 | 375 | } |
duke@1 | 376 | public Object next() { |
duke@1 | 377 | throw new java.util.NoSuchElementException(); |
duke@1 | 378 | } |
duke@1 | 379 | public void remove() { |
duke@1 | 380 | throw new UnsupportedOperationException(); |
duke@1 | 381 | } |
duke@1 | 382 | }; |
duke@1 | 383 | |
duke@1 | 384 | @SuppressWarnings("unchecked") |
duke@1 | 385 | private static <A> Iterator<A> emptyIterator() { |
mcimadamore@184 | 386 | return (Iterator<A>)EMPTYITERATOR; |
duke@1 | 387 | } |
duke@1 | 388 | |
duke@1 | 389 | @Override |
duke@1 | 390 | public Iterator<A> iterator() { |
duke@1 | 391 | if (tail == null) |
duke@1 | 392 | return emptyIterator(); |
duke@1 | 393 | return new Iterator<A>() { |
duke@1 | 394 | List<A> elems = List.this; |
duke@1 | 395 | public boolean hasNext() { |
duke@1 | 396 | return elems.tail != null; |
duke@1 | 397 | } |
duke@1 | 398 | public A next() { |
duke@1 | 399 | if (elems.tail == null) |
duke@1 | 400 | throw new NoSuchElementException(); |
duke@1 | 401 | A result = elems.head; |
duke@1 | 402 | elems = elems.tail; |
duke@1 | 403 | return result; |
duke@1 | 404 | } |
duke@1 | 405 | public void remove() { |
duke@1 | 406 | throw new UnsupportedOperationException(); |
duke@1 | 407 | } |
duke@1 | 408 | }; |
duke@1 | 409 | } |
duke@1 | 410 | |
duke@1 | 411 | public A get(int index) { |
duke@1 | 412 | if (index < 0) |
duke@1 | 413 | throw new IndexOutOfBoundsException(String.valueOf(index)); |
duke@1 | 414 | |
duke@1 | 415 | List<A> l = this; |
duke@1 | 416 | for (int i = index; i-- > 0 && !l.isEmpty(); l = l.tail) |
duke@1 | 417 | ; |
duke@1 | 418 | |
duke@1 | 419 | if (l.isEmpty()) |
duke@1 | 420 | throw new IndexOutOfBoundsException("Index: " + index + ", " + |
duke@1 | 421 | "Size: " + size()); |
duke@1 | 422 | return l.head; |
duke@1 | 423 | } |
duke@1 | 424 | |
duke@1 | 425 | public boolean addAll(int index, Collection<? extends A> c) { |
duke@1 | 426 | if (c.isEmpty()) |
duke@1 | 427 | return false; |
duke@1 | 428 | throw new UnsupportedOperationException(); |
duke@1 | 429 | } |
duke@1 | 430 | |
duke@1 | 431 | public A set(int index, A element) { |
duke@1 | 432 | throw new UnsupportedOperationException(); |
duke@1 | 433 | } |
duke@1 | 434 | |
duke@1 | 435 | public void add(int index, A element) { |
duke@1 | 436 | throw new UnsupportedOperationException(); |
duke@1 | 437 | } |
duke@1 | 438 | |
duke@1 | 439 | public A remove(int index) { |
duke@1 | 440 | throw new UnsupportedOperationException(); |
duke@1 | 441 | } |
duke@1 | 442 | |
duke@1 | 443 | public int indexOf(Object o) { |
duke@1 | 444 | int i = 0; |
duke@1 | 445 | for (List<A> l = this; l.tail != null; l = l.tail, i++) { |
duke@1 | 446 | if (l.head == null ? o == null : l.head.equals(o)) |
duke@1 | 447 | return i; |
duke@1 | 448 | } |
duke@1 | 449 | return -1; |
duke@1 | 450 | } |
duke@1 | 451 | |
duke@1 | 452 | public int lastIndexOf(Object o) { |
duke@1 | 453 | int last = -1; |
duke@1 | 454 | int i = 0; |
duke@1 | 455 | for (List<A> l = this; l.tail != null; l = l.tail, i++) { |
duke@1 | 456 | if (l.head == null ? o == null : l.head.equals(o)) |
duke@1 | 457 | last = i; |
duke@1 | 458 | } |
duke@1 | 459 | return last; |
duke@1 | 460 | } |
duke@1 | 461 | |
duke@1 | 462 | public ListIterator<A> listIterator() { |
duke@1 | 463 | return Collections.unmodifiableList(new ArrayList<A>(this)).listIterator(); |
duke@1 | 464 | } |
duke@1 | 465 | |
duke@1 | 466 | public ListIterator<A> listIterator(int index) { |
duke@1 | 467 | return Collections.unmodifiableList(new ArrayList<A>(this)).listIterator(index); |
duke@1 | 468 | } |
duke@1 | 469 | |
duke@1 | 470 | public java.util.List<A> subList(int fromIndex, int toIndex) { |
duke@1 | 471 | if (fromIndex < 0 || toIndex > size() || fromIndex > toIndex) |
duke@1 | 472 | throw new IllegalArgumentException(); |
duke@1 | 473 | |
duke@1 | 474 | ArrayList<A> a = new ArrayList<A>(toIndex - fromIndex); |
duke@1 | 475 | int i = 0; |
duke@1 | 476 | for (List<A> l = this; l.tail != null; l = l.tail, i++) { |
duke@1 | 477 | if (i == toIndex) |
duke@1 | 478 | break; |
duke@1 | 479 | if (i >= fromIndex) |
duke@1 | 480 | a.add(l.head); |
duke@1 | 481 | } |
duke@1 | 482 | |
duke@1 | 483 | return Collections.unmodifiableList(a); |
duke@1 | 484 | } |
duke@1 | 485 | } |