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| 1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file | |
| 2 // for details. All rights reserved. Use of this source code is governed by a | |
| 3 // BSD-style license that can be found in the LICENSE file. | |
| 4 | |
| 5 part of dart._collection.dev; | |
| 6 | |
| 7 /** | |
| 8 * Marker interface for [Iterable] subclasses that have an efficient | |
| 9 * [length] implementation. | |
| 10 */ | |
| 11 abstract class EfficientLength { | |
| 12 /** | |
| 13 * Returns the number of elements in the iterable. | |
| 14 * | |
| 15 * This is an efficient operation that doesn't require iterating through | |
| 16 * the elements. | |
| 17 */ | |
| 18 int get length; | |
| 19 } | |
| 20 | |
| 21 /** | |
| 22 * An [Iterable] for classes that have efficient [length] and [elementAt]. | |
| 23 * | |
| 24 * All other methods are implemented in terms of [length] and [elementAt], | |
| 25 * including [iterator]. | |
| 26 */ | |
| 27 abstract class ListIterable<E> extends IterableBase<E> | |
| 28 implements EfficientLength { | |
| 29 int get length; | |
| 30 E elementAt(int i); | |
| 31 | |
| 32 const ListIterable(); | |
| 33 | |
| 34 Iterator<E> get iterator => new ListIterator<E>(this); | |
| 35 | |
| 36 void forEach(void action(E element)) { | |
| 37 int length = this.length; | |
| 38 for (int i = 0; i < length; i++) { | |
| 39 action(elementAt(i)); | |
| 40 if (length != this.length) { | |
| 41 throw new ConcurrentModificationError(this); | |
| 42 } | |
| 43 } | |
| 44 } | |
| 45 | |
| 46 bool get isEmpty => length == 0; | |
| 47 | |
| 48 E get first { | |
| 49 if (length == 0) throw new StateError("No elements"); | |
| 50 return elementAt(0); | |
| 51 } | |
| 52 | |
| 53 E get last { | |
| 54 if (length == 0) throw new StateError("No elements"); | |
| 55 return elementAt(length - 1); | |
| 56 } | |
| 57 | |
| 58 E get single { | |
| 59 if (length == 0) throw new StateError("No elements"); | |
| 60 if (length > 1) throw new StateError("Too many elements"); | |
| 61 return elementAt(0); | |
| 62 } | |
| 63 | |
| 64 bool contains(Object element) { | |
| 65 int length = this.length; | |
| 66 for (int i = 0; i < length; i++) { | |
| 67 if (elementAt(i) == element) return true; | |
| 68 if (length != this.length) { | |
| 69 throw new ConcurrentModificationError(this); | |
| 70 } | |
| 71 } | |
| 72 return false; | |
| 73 } | |
| 74 | |
| 75 bool every(bool test(E element)) { | |
| 76 int length = this.length; | |
| 77 for (int i = 0; i < length; i++) { | |
| 78 if (!test(elementAt(i))) return false; | |
| 79 if (length != this.length) { | |
| 80 throw new ConcurrentModificationError(this); | |
| 81 } | |
| 82 } | |
| 83 return true; | |
| 84 } | |
| 85 | |
| 86 bool any(bool test(E element)) { | |
| 87 int length = this.length; | |
| 88 for (int i = 0; i < length; i++) { | |
| 89 if (test(elementAt(i))) return true; | |
| 90 if (length != this.length) { | |
| 91 throw new ConcurrentModificationError(this); | |
| 92 } | |
| 93 } | |
| 94 return false; | |
| 95 } | |
| 96 | |
| 97 dynamic firstWhere(bool test(E element), { Object orElse() }) { | |
| 98 int length = this.length; | |
| 99 for (int i = 0; i < length; i++) { | |
| 100 E element = elementAt(i); | |
| 101 if (test(element)) return element; | |
| 102 if (length != this.length) { | |
| 103 throw new ConcurrentModificationError(this); | |
| 104 } | |
| 105 } | |
| 106 if (orElse != null) return orElse(); | |
| 107 throw new StateError("No matching element"); | |
| 108 } | |
| 109 | |
| 110 dynamic lastWhere(bool test(E element), { Object orElse() }) { | |
| 111 int length = this.length; | |
| 112 for (int i = length - 1; i >= 0; i--) { | |
| 113 E element = elementAt(i); | |
| 114 if (test(element)) return element; | |
| 115 if (length != this.length) { | |
| 116 throw new ConcurrentModificationError(this); | |
| 117 } | |
| 118 } | |
| 119 if (orElse != null) return orElse(); | |
| 120 throw new StateError("No matching element"); | |
| 121 } | |
| 122 | |
| 123 E singleWhere(bool test(E element)) { | |
| 124 int length = this.length; | |
| 125 E match = null; | |
| 126 bool matchFound = false; | |
| 127 for (int i = 0; i < length; i++) { | |
| 128 E element = elementAt(i); | |
| 129 if (test(element)) { | |
| 130 if (matchFound) { | |
| 131 throw new StateError("More than one matching element"); | |
| 132 } | |
| 133 matchFound = true; | |
| 134 match = element; | |
| 135 } | |
| 136 if (length != this.length) { | |
| 137 throw new ConcurrentModificationError(this); | |
| 138 } | |
| 139 } | |
| 140 if (matchFound) return match; | |
| 141 throw new StateError("No matching element"); | |
| 142 } | |
| 143 | |
| 144 String join([String separator = ""]) { | |
| 145 int length = this.length; | |
| 146 if (!separator.isEmpty) { | |
| 147 if (length == 0) return ""; | |
| 148 String first = "${elementAt(0)}"; | |
| 149 if (length != this.length) { | |
| 150 throw new ConcurrentModificationError(this); | |
| 151 } | |
| 152 StringBuffer buffer = new StringBuffer(first); | |
| 153 for (int i = 1; i < length; i++) { | |
| 154 buffer.write(separator); | |
| 155 buffer.write(elementAt(i)); | |
| 156 if (length != this.length) { | |
| 157 throw new ConcurrentModificationError(this); | |
| 158 } | |
| 159 } | |
| 160 return buffer.toString(); | |
| 161 } else { | |
| 162 StringBuffer buffer = new StringBuffer(); | |
| 163 for (int i = 0; i < length; i++) { | |
| 164 buffer.write(elementAt(i)); | |
| 165 if (length != this.length) { | |
| 166 throw new ConcurrentModificationError(this); | |
| 167 } | |
| 168 } | |
| 169 return buffer.toString(); | |
| 170 } | |
| 171 } | |
| 172 | |
| 173 Iterable<E> where(bool test(E element)) => super.where(test); | |
| 174 | |
| 175 Iterable map(f(E element)) => new MappedListIterable(this, f); | |
| 176 | |
| 177 E reduce(E combine(var value, E element)) { | |
| 178 if (length == 0) throw new StateError("No elements"); | |
| 179 E value = elementAt(0); | |
| 180 for (int i = 1; i < length; i++) { | |
| 181 value = combine(value, elementAt(i)); | |
| 182 } | |
| 183 return value; | |
| 184 } | |
| 185 | |
| 186 fold(var initialValue, combine(var previousValue, E element)) { | |
| 187 var value = initialValue; | |
| 188 int length = this.length; | |
| 189 for (int i = 0; i < length; i++) { | |
| 190 value = combine(value, elementAt(i)); | |
| 191 if (length != this.length) { | |
| 192 throw new ConcurrentModificationError(this); | |
| 193 } | |
| 194 } | |
| 195 return value; | |
| 196 } | |
| 197 | |
| 198 Iterable<E> skip(int count) => new SubListIterable(this, count, null); | |
| 199 | |
| 200 Iterable<E> skipWhile(bool test(E element)) => super.skipWhile(test); | |
| 201 | |
| 202 Iterable<E> take(int count) => new SubListIterable(this, 0, count); | |
| 203 | |
| 204 Iterable<E> takeWhile(bool test(E element)) => super.takeWhile(test); | |
| 205 | |
| 206 List<E> toList({ bool growable: true }) { | |
| 207 List<E> result; | |
| 208 if (growable) { | |
| 209 result = new List<E>()..length = length; | |
| 210 } else { | |
| 211 result = new List<E>(length); | |
| 212 } | |
| 213 for (int i = 0; i < length; i++) { | |
| 214 result[i] = elementAt(i); | |
| 215 } | |
| 216 return result; | |
| 217 } | |
| 218 | |
| 219 Set<E> toSet() { | |
| 220 Set<E> result = new Set<E>(); | |
| 221 for (int i = 0; i < length; i++) { | |
| 222 result.add(elementAt(i)); | |
| 223 } | |
| 224 return result; | |
| 225 } | |
| 226 } | |
| 227 | |
| 228 class SubListIterable<E> extends ListIterable<E> { | |
| 229 final Iterable<E> _iterable; | |
| 230 final int _start; | |
| 231 /** If null, represents the length of the iterable. */ | |
| 232 final int _endOrLength; | |
| 233 | |
| 234 SubListIterable(this._iterable, this._start, this._endOrLength) { | |
| 235 if (_start < 0) { | |
| 236 throw new RangeError.value(_start); | |
| 237 } | |
| 238 if (_endOrLength != null) { | |
| 239 if (_endOrLength < 0) { | |
| 240 throw new RangeError.value(_endOrLength); | |
| 241 } | |
| 242 if (_start > _endOrLength) { | |
| 243 throw new RangeError.range(_start, 0, _endOrLength); | |
| 244 } | |
| 245 } | |
| 246 } | |
| 247 | |
| 248 int get _endIndex { | |
| 249 int length = _iterable.length; | |
| 250 if (_endOrLength == null || _endOrLength > length) return length; | |
| 251 return _endOrLength; | |
| 252 } | |
| 253 | |
| 254 int get _startIndex { | |
| 255 int length = _iterable.length; | |
| 256 if (_start > length) return length; | |
| 257 return _start; | |
| 258 } | |
| 259 | |
| 260 int get length { | |
| 261 int length = _iterable.length; | |
| 262 if (_start >= length) return 0; | |
| 263 if (_endOrLength == null || _endOrLength >= length) { | |
| 264 return length - _start; | |
| 265 } | |
| 266 return _endOrLength - _start; | |
| 267 } | |
| 268 | |
| 269 E elementAt(int index) { | |
| 270 int realIndex = _startIndex + index; | |
| 271 if (index < 0 || realIndex >= _endIndex) { | |
| 272 throw new RangeError.range(index, 0, length); | |
| 273 } | |
| 274 return _iterable.elementAt(realIndex); | |
| 275 } | |
| 276 | |
| 277 Iterable<E> skip(int count) { | |
| 278 if (count < 0) throw new RangeError.value(count); | |
| 279 return new SubListIterable(_iterable, _start + count, _endOrLength); | |
| 280 } | |
| 281 | |
| 282 Iterable<E> take(int count) { | |
| 283 if (count < 0) throw new RangeError.value(count); | |
| 284 if (_endOrLength == null) { | |
| 285 return new SubListIterable(_iterable, _start, _start + count); | |
| 286 } else { | |
| 287 int newEnd = _start + count; | |
| 288 if (_endOrLength < newEnd) return this; | |
| 289 return new SubListIterable(_iterable, _start, newEnd); | |
| 290 } | |
| 291 } | |
| 292 } | |
| 293 | |
| 294 /** | |
| 295 * An [Iterator] that iterates a list-like [Iterable]. | |
| 296 * | |
| 297 * All iterations is done in terms of [Iterable.length] and | |
| 298 * [Iterable.elementAt]. These operations are fast for list-like | |
| 299 * iterables. | |
| 300 */ | |
| 301 class ListIterator<E> implements Iterator<E> { | |
| 302 final Iterable<E> _iterable; | |
| 303 final int _length; | |
| 304 int _index; | |
| 305 E _current; | |
| 306 | |
| 307 ListIterator(Iterable<E> iterable) | |
| 308 : _iterable = iterable, _length = iterable.length, _index = 0; | |
| 309 | |
| 310 E get current => _current; | |
| 311 | |
| 312 bool moveNext() { | |
| 313 int length = _iterable.length; | |
| 314 if (_length != length) { | |
| 315 throw new ConcurrentModificationError(_iterable); | |
| 316 } | |
| 317 if (_index >= length) { | |
| 318 _current = null; | |
| 319 return false; | |
| 320 } | |
| 321 _current = _iterable.elementAt(_index); | |
| 322 _index++; | |
| 323 return true; | |
| 324 } | |
| 325 } | |
| 326 | |
| 327 typedef T _Transformation<S, T>(S value); | |
| 328 | |
| 329 class MappedIterable<S, T> extends IterableBase<T> { | |
| 330 final Iterable<S> _iterable; | |
| 331 final _Transformation<S, T> _f; | |
| 332 | |
| 333 factory MappedIterable(Iterable iterable, T function(S value)) { | |
| 334 if (iterable is EfficientLength) { | |
| 335 return new EfficientLengthMappedIterable<S, T>(iterable, function); | |
| 336 } | |
| 337 return new MappedIterable<S, T>._(iterable, function); | |
| 338 } | |
| 339 | |
| 340 MappedIterable._(this._iterable, T this._f(S element)); | |
| 341 | |
| 342 Iterator<T> get iterator => new MappedIterator<S, T>(_iterable.iterator, _f); | |
| 343 | |
| 344 // Length related functions are independent of the mapping. | |
| 345 int get length => _iterable.length; | |
| 346 bool get isEmpty => _iterable.isEmpty; | |
| 347 | |
| 348 // Index based lookup can be done before transforming. | |
| 349 T get first => _f(_iterable.first); | |
| 350 T get last => _f(_iterable.last); | |
| 351 T get single => _f(_iterable.single); | |
| 352 T elementAt(int index) => _f(_iterable.elementAt(index)); | |
| 353 } | |
| 354 | |
| 355 class EfficientLengthMappedIterable<S, T> extends MappedIterable<S, T> | |
| 356 implements EfficientLength { | |
| 357 EfficientLengthMappedIterable(Iterable iterable, T function(S value)) | |
| 358 : super._(iterable, function); | |
| 359 } | |
| 360 | |
| 361 class MappedIterator<S, T> extends Iterator<T> { | |
| 362 T _current; | |
| 363 final Iterator<S> _iterator; | |
| 364 final _Transformation<S, T> _f; | |
| 365 | |
| 366 MappedIterator(this._iterator, T this._f(S element)); | |
| 367 | |
| 368 bool moveNext() { | |
| 369 if (_iterator.moveNext()) { | |
| 370 _current = _f(_iterator.current); | |
| 371 return true; | |
| 372 } | |
| 373 _current = null; | |
| 374 return false; | |
| 375 } | |
| 376 | |
| 377 T get current => _current; | |
| 378 } | |
| 379 | |
| 380 /** | |
| 381 * Specialized alternative to [MappedIterable] for mapped [List]s. | |
| 382 * | |
| 383 * Expects efficient `length` and `elementAt` on the source iterable. | |
| 384 */ | |
| 385 class MappedListIterable<S, T> extends ListIterable<T> | |
| 386 implements EfficientLength { | |
| 387 final Iterable<S> _source; | |
| 388 final _Transformation<S, T> _f; | |
| 389 | |
| 390 MappedListIterable(this._source, T this._f(S value)); | |
| 391 | |
| 392 int get length => _source.length; | |
| 393 T elementAt(int index) => _f(_source.elementAt(index)); | |
| 394 } | |
| 395 | |
| 396 | |
| 397 typedef bool _ElementPredicate<E>(E element); | |
| 398 | |
| 399 class WhereIterable<E> extends IterableBase<E> { | |
| 400 final Iterable<E> _iterable; | |
| 401 final _ElementPredicate _f; | |
| 402 | |
| 403 WhereIterable(this._iterable, bool this._f(E element)); | |
| 404 | |
| 405 Iterator<E> get iterator => new WhereIterator<E>(_iterable.iterator, _f); | |
| 406 } | |
| 407 | |
| 408 class WhereIterator<E> extends Iterator<E> { | |
| 409 final Iterator<E> _iterator; | |
| 410 final _ElementPredicate _f; | |
| 411 | |
| 412 WhereIterator(this._iterator, bool this._f(E element)); | |
| 413 | |
| 414 bool moveNext() { | |
| 415 while (_iterator.moveNext()) { | |
| 416 if (_f(_iterator.current)) { | |
| 417 return true; | |
| 418 } | |
| 419 } | |
| 420 return false; | |
| 421 } | |
| 422 | |
| 423 E get current => _iterator.current; | |
| 424 } | |
| 425 | |
| 426 typedef Iterable<T> _ExpandFunction<S, T>(S sourceElement); | |
| 427 | |
| 428 class ExpandIterable<S, T> extends IterableBase<T> { | |
| 429 final Iterable<S> _iterable; | |
| 430 final _ExpandFunction _f; | |
| 431 | |
| 432 ExpandIterable(this._iterable, Iterable<T> this._f(S element)); | |
| 433 | |
| 434 Iterator<T> get iterator => new ExpandIterator<S, T>(_iterable.iterator, _f); | |
| 435 } | |
| 436 | |
| 437 class ExpandIterator<S, T> implements Iterator<T> { | |
| 438 final Iterator<S> _iterator; | |
| 439 final _ExpandFunction _f; | |
| 440 // Initialize _currentExpansion to an empty iterable. A null value | |
| 441 // marks the end of iteration, and we don't want to call _f before | |
| 442 // the first moveNext call. | |
| 443 Iterator<T> _currentExpansion = const EmptyIterator(); | |
| 444 T _current; | |
| 445 | |
| 446 ExpandIterator(this._iterator, Iterable<T> this._f(S element)); | |
| 447 | |
| 448 void _nextExpansion() { | |
| 449 } | |
| 450 | |
| 451 T get current => _current; | |
| 452 | |
| 453 bool moveNext() { | |
| 454 if (_currentExpansion == null) return false; | |
| 455 while (!_currentExpansion.moveNext()) { | |
| 456 _current = null; | |
| 457 if (_iterator.moveNext()) { | |
| 458 // If _f throws, this ends iteration. Otherwise _currentExpansion and | |
| 459 // _current will be set again below. | |
| 460 _currentExpansion = null; | |
| 461 _currentExpansion = _f(_iterator.current).iterator; | |
| 462 } else { | |
| 463 return false; | |
| 464 } | |
| 465 } | |
| 466 _current = _currentExpansion.current; | |
| 467 return true; | |
| 468 } | |
| 469 } | |
| 470 | |
| 471 class TakeIterable<E> extends IterableBase<E> { | |
| 472 final Iterable<E> _iterable; | |
| 473 final int _takeCount; | |
| 474 | |
| 475 factory TakeIterable(Iterable<E> iterable, int takeCount) { | |
| 476 if (takeCount is! int || takeCount < 0) { | |
| 477 throw new ArgumentError(takeCount); | |
| 478 } | |
| 479 if (iterable is EfficientLength) { | |
| 480 return new EfficientLengthTakeIterable<E>(iterable, takeCount); | |
| 481 } | |
| 482 return new TakeIterable<E>._(iterable, takeCount); | |
| 483 } | |
| 484 | |
| 485 TakeIterable._(this._iterable, this._takeCount); | |
| 486 | |
| 487 Iterator<E> get iterator { | |
| 488 return new TakeIterator<E>(_iterable.iterator, _takeCount); | |
| 489 } | |
| 490 } | |
| 491 | |
| 492 class EfficientLengthTakeIterable<E> extends TakeIterable<E> | |
| 493 implements EfficientLength { | |
| 494 EfficientLengthTakeIterable(Iterable<E> iterable, int takeCount) | |
| 495 : super._(iterable, takeCount); | |
| 496 | |
| 497 int get length { | |
| 498 int iterableLength = _iterable.length; | |
| 499 if (iterableLength > _takeCount) return _takeCount; | |
| 500 return iterableLength; | |
| 501 } | |
| 502 } | |
| 503 | |
| 504 | |
| 505 class TakeIterator<E> extends Iterator<E> { | |
| 506 final Iterator<E> _iterator; | |
| 507 int _remaining; | |
| 508 | |
| 509 TakeIterator(this._iterator, this._remaining) { | |
| 510 assert(_remaining is int && _remaining >= 0); | |
| 511 } | |
| 512 | |
| 513 bool moveNext() { | |
| 514 _remaining--; | |
| 515 if (_remaining >= 0) { | |
| 516 return _iterator.moveNext(); | |
| 517 } | |
| 518 _remaining = -1; | |
| 519 return false; | |
| 520 } | |
| 521 | |
| 522 E get current { | |
| 523 if (_remaining < 0) return null; | |
| 524 return _iterator.current; | |
| 525 } | |
| 526 } | |
| 527 | |
| 528 class TakeWhileIterable<E> extends IterableBase<E> { | |
| 529 final Iterable<E> _iterable; | |
| 530 final _ElementPredicate _f; | |
| 531 | |
| 532 TakeWhileIterable(this._iterable, bool this._f(E element)); | |
| 533 | |
| 534 Iterator<E> get iterator { | |
| 535 return new TakeWhileIterator<E>(_iterable.iterator, _f); | |
| 536 } | |
| 537 } | |
| 538 | |
| 539 class TakeWhileIterator<E> extends Iterator<E> { | |
| 540 final Iterator<E> _iterator; | |
| 541 final _ElementPredicate _f; | |
| 542 bool _isFinished = false; | |
| 543 | |
| 544 TakeWhileIterator(this._iterator, bool this._f(E element)); | |
| 545 | |
| 546 bool moveNext() { | |
| 547 if (_isFinished) return false; | |
| 548 if (!_iterator.moveNext() || !_f(_iterator.current)) { | |
| 549 _isFinished = true; | |
| 550 return false; | |
| 551 } | |
| 552 return true; | |
| 553 } | |
| 554 | |
| 555 E get current { | |
| 556 if (_isFinished) return null; | |
| 557 return _iterator.current; | |
| 558 } | |
| 559 } | |
| 560 | |
| 561 class SkipIterable<E> extends IterableBase<E> { | |
| 562 final Iterable<E> _iterable; | |
| 563 final int _skipCount; | |
| 564 | |
| 565 factory SkipIterable(Iterable<E> iterable, int skipCount) { | |
| 566 if (iterable is EfficientLength) { | |
| 567 return new EfficientLengthSkipIterable<E>(iterable, skipCount); | |
| 568 } | |
| 569 return new SkipIterable<E>._(iterable, skipCount); | |
| 570 } | |
| 571 | |
| 572 SkipIterable._(this._iterable, this._skipCount) { | |
| 573 if (_skipCount is! int || _skipCount < 0) { | |
| 574 throw new RangeError(_skipCount); | |
| 575 } | |
| 576 } | |
| 577 | |
| 578 Iterable<E> skip(int n) { | |
| 579 if (n is! int || n < 0) { | |
| 580 throw new RangeError.value(n); | |
| 581 } | |
| 582 return new SkipIterable<E>(_iterable, _skipCount + n); | |
| 583 } | |
| 584 | |
| 585 Iterator<E> get iterator { | |
| 586 return new SkipIterator<E>(_iterable.iterator, _skipCount); | |
| 587 } | |
| 588 } | |
| 589 | |
| 590 class EfficientLengthSkipIterable<E> extends SkipIterable<E> | |
| 591 implements EfficientLength { | |
| 592 EfficientLengthSkipIterable(Iterable<E> iterable, int skipCount) | |
| 593 : super._(iterable, skipCount); | |
| 594 | |
| 595 int get length { | |
| 596 int length = _iterable.length - _skipCount; | |
| 597 if (length >= 0) return length; | |
| 598 return 0; | |
| 599 } | |
| 600 } | |
| 601 | |
| 602 class SkipIterator<E> extends Iterator<E> { | |
| 603 final Iterator<E> _iterator; | |
| 604 int _skipCount; | |
| 605 | |
| 606 SkipIterator(this._iterator, this._skipCount) { | |
| 607 assert(_skipCount is int && _skipCount >= 0); | |
| 608 } | |
| 609 | |
| 610 bool moveNext() { | |
| 611 for (int i = 0; i < _skipCount; i++) _iterator.moveNext(); | |
| 612 _skipCount = 0; | |
| 613 return _iterator.moveNext(); | |
| 614 } | |
| 615 | |
| 616 E get current => _iterator.current; | |
| 617 } | |
| 618 | |
| 619 class SkipWhileIterable<E> extends IterableBase<E> { | |
| 620 final Iterable<E> _iterable; | |
| 621 final _ElementPredicate _f; | |
| 622 | |
| 623 SkipWhileIterable(this._iterable, bool this._f(E element)); | |
| 624 | |
| 625 Iterator<E> get iterator { | |
| 626 return new SkipWhileIterator<E>(_iterable.iterator, _f); | |
| 627 } | |
| 628 } | |
| 629 | |
| 630 class SkipWhileIterator<E> extends Iterator<E> { | |
| 631 final Iterator<E> _iterator; | |
| 632 final _ElementPredicate _f; | |
| 633 bool _hasSkipped = false; | |
| 634 | |
| 635 SkipWhileIterator(this._iterator, bool this._f(E element)); | |
| 636 | |
| 637 bool moveNext() { | |
| 638 if (!_hasSkipped) { | |
| 639 _hasSkipped = true; | |
| 640 while (_iterator.moveNext()) { | |
| 641 if (!_f(_iterator.current)) return true; | |
| 642 } | |
| 643 } | |
| 644 return _iterator.moveNext(); | |
| 645 } | |
| 646 | |
| 647 E get current => _iterator.current; | |
| 648 } | |
| 649 | |
| 650 /** | |
| 651 * The always empty [Iterable]. | |
| 652 */ | |
| 653 class EmptyIterable<E> extends IterableBase<E> implements EfficientLength { | |
| 654 const EmptyIterable(); | |
| 655 | |
| 656 Iterator<E> get iterator => const EmptyIterator(); | |
| 657 | |
| 658 void forEach(void action(E element)) {} | |
| 659 | |
| 660 bool get isEmpty => true; | |
| 661 | |
| 662 int get length => 0; | |
| 663 | |
| 664 E get first { throw new StateError("No elements"); } | |
| 665 | |
| 666 E get last { throw new StateError("No elements"); } | |
| 667 | |
| 668 E get single { throw new StateError("No elements"); } | |
| 669 | |
| 670 E elementAt(int index) { throw new RangeError.value(index); } | |
| 671 | |
| 672 bool contains(Object element) => false; | |
| 673 | |
| 674 bool every(bool test(E element)) => true; | |
| 675 | |
| 676 bool any(bool test(E element)) => false; | |
| 677 | |
| 678 E firstWhere(bool test(E element), { E orElse() }) { | |
| 679 if (orElse != null) return orElse(); | |
| 680 throw new StateError("No matching element"); | |
| 681 } | |
| 682 | |
| 683 E lastWhere(bool test(E element), { E orElse() }) { | |
| 684 if (orElse != null) return orElse(); | |
| 685 throw new StateError("No matching element"); | |
| 686 } | |
| 687 | |
| 688 E singleWhere(bool test(E element), { E orElse() }) { | |
| 689 if (orElse != null) return orElse(); | |
| 690 throw new StateError("No matching element"); | |
| 691 } | |
| 692 | |
| 693 String join([String separator = ""]) => ""; | |
| 694 | |
| 695 Iterable<E> where(bool test(E element)) => this; | |
| 696 | |
| 697 Iterable map(f(E element)) => const EmptyIterable(); | |
| 698 | |
| 699 E reduce(E combine(E value, E element)) { | |
| 700 throw new StateError("No elements"); | |
| 701 } | |
| 702 | |
| 703 fold(var initialValue, combine(var previousValue, E element)) { | |
| 704 return initialValue; | |
| 705 } | |
| 706 | |
| 707 Iterable<E> skip(int count) { | |
| 708 if (count < 0) throw new RangeError.value(count); | |
| 709 return this; | |
| 710 } | |
| 711 | |
| 712 Iterable<E> skipWhile(bool test(E element)) => this; | |
| 713 | |
| 714 Iterable<E> take(int count) { | |
| 715 if (count < 0) throw new RangeError.value(count); | |
| 716 this; | |
| 717 } | |
| 718 | |
| 719 Iterable<E> takeWhile(bool test(E element)) => this; | |
| 720 | |
| 721 List toList({ bool growable: true }) => growable ? <E>[] : new List<E>(0); | |
| 722 | |
| 723 Set toSet() => new Set<E>(); | |
| 724 } | |
| 725 | |
| 726 /** The always empty iterator. */ | |
| 727 class EmptyIterator<E> implements Iterator<E> { | |
| 728 const EmptyIterator(); | |
| 729 bool moveNext() => false; | |
| 730 E get current => null; | |
| 731 } | |
| 732 | |
| 733 /** An [Iterator] that can move in both directions. */ | |
| 734 abstract class BidirectionalIterator<T> implements Iterator<T> { | |
| 735 bool movePrevious(); | |
| 736 } | |
| 737 | |
| 738 /** | |
| 739 * This class provides default implementations for Iterables (including Lists). | |
| 740 * | |
| 741 * The uses of this class will be replaced by mixins. | |
| 742 */ | |
| 743 class IterableMixinWorkaround { | |
| 744 // A list to identify cyclic collections during toString() calls. | |
| 745 static List _toStringList = new List(); | |
| 746 | |
| 747 static bool contains(Iterable iterable, var element) { | |
| 748 for (final e in iterable) { | |
| 749 if (e == element) return true; | |
| 750 } | |
| 751 return false; | |
| 752 } | |
| 753 | |
| 754 static void forEach(Iterable iterable, void f(o)) { | |
| 755 for (final e in iterable) { | |
| 756 f(e); | |
| 757 } | |
| 758 } | |
| 759 | |
| 760 static bool any(Iterable iterable, bool f(o)) { | |
| 761 for (final e in iterable) { | |
| 762 if (f(e)) return true; | |
| 763 } | |
| 764 return false; | |
| 765 } | |
| 766 | |
| 767 static bool every(Iterable iterable, bool f(o)) { | |
| 768 for (final e in iterable) { | |
| 769 if (!f(e)) return false; | |
| 770 } | |
| 771 return true; | |
| 772 } | |
| 773 | |
| 774 static dynamic reduce(Iterable iterable, | |
| 775 dynamic combine(previousValue, element)) { | |
| 776 Iterator iterator = iterable.iterator; | |
| 777 if (!iterator.moveNext()) throw new StateError("No elements"); | |
| 778 var value = iterator.current; | |
| 779 while (iterator.moveNext()) { | |
| 780 value = combine(value, iterator.current); | |
| 781 } | |
| 782 return value; | |
| 783 } | |
| 784 | |
| 785 static dynamic fold(Iterable iterable, | |
| 786 dynamic initialValue, | |
| 787 dynamic combine(dynamic previousValue, element)) { | |
| 788 for (final element in iterable) { | |
| 789 initialValue = combine(initialValue, element); | |
| 790 } | |
| 791 return initialValue; | |
| 792 } | |
| 793 | |
| 794 /** | |
| 795 * Removes elements matching [test] from [list]. | |
| 796 * | |
| 797 * This is performed in two steps, to avoid exposing an inconsistent state | |
| 798 * to the [test] function. First the elements to retain are found, and then | |
| 799 * the original list is updated to contain those elements. | |
| 800 */ | |
| 801 static void removeWhereList(List list, bool test(var element)) { | |
| 802 List retained = []; | |
| 803 int length = list.length; | |
| 804 for (int i = 0; i < length; i++) { | |
| 805 var element = list[i]; | |
| 806 if (!test(element)) { | |
| 807 retained.add(element); | |
| 808 } | |
| 809 if (length != list.length) { | |
| 810 throw new ConcurrentModificationError(list); | |
| 811 } | |
| 812 } | |
| 813 if (retained.length == length) return; | |
| 814 list.length = retained.length; | |
| 815 for (int i = 0; i < retained.length; i++) { | |
| 816 list[i] = retained[i]; | |
| 817 } | |
| 818 } | |
| 819 | |
| 820 static bool isEmpty(Iterable iterable) { | |
| 821 return !iterable.iterator.moveNext(); | |
| 822 } | |
| 823 | |
| 824 static dynamic first(Iterable iterable) { | |
| 825 Iterator it = iterable.iterator; | |
| 826 if (!it.moveNext()) { | |
| 827 throw new StateError("No elements"); | |
| 828 } | |
| 829 return it.current; | |
| 830 } | |
| 831 | |
| 832 static dynamic last(Iterable iterable) { | |
| 833 Iterator it = iterable.iterator; | |
| 834 if (!it.moveNext()) { | |
| 835 throw new StateError("No elements"); | |
| 836 } | |
| 837 dynamic result; | |
| 838 do { | |
| 839 result = it.current; | |
| 840 } while(it.moveNext()); | |
| 841 return result; | |
| 842 } | |
| 843 | |
| 844 static dynamic single(Iterable iterable) { | |
| 845 Iterator it = iterable.iterator; | |
| 846 if (!it.moveNext()) throw new StateError("No elements"); | |
| 847 dynamic result = it.current; | |
| 848 if (it.moveNext()) throw new StateError("More than one element"); | |
| 849 return result; | |
| 850 } | |
| 851 | |
| 852 static dynamic firstWhere(Iterable iterable, | |
| 853 bool test(dynamic value), | |
| 854 dynamic orElse()) { | |
| 855 for (dynamic element in iterable) { | |
| 856 if (test(element)) return element; | |
| 857 } | |
| 858 if (orElse != null) return orElse(); | |
| 859 throw new StateError("No matching element"); | |
| 860 } | |
| 861 | |
| 862 static dynamic lastWhere(Iterable iterable, | |
| 863 bool test(dynamic value), | |
| 864 dynamic orElse()) { | |
| 865 dynamic result = null; | |
| 866 bool foundMatching = false; | |
| 867 for (dynamic element in iterable) { | |
| 868 if (test(element)) { | |
| 869 result = element; | |
| 870 foundMatching = true; | |
| 871 } | |
| 872 } | |
| 873 if (foundMatching) return result; | |
| 874 if (orElse != null) return orElse(); | |
| 875 throw new StateError("No matching element"); | |
| 876 } | |
| 877 | |
| 878 static dynamic lastWhereList(List list, | |
| 879 bool test(dynamic value), | |
| 880 dynamic orElse()) { | |
| 881 // TODO(floitsch): check that arguments are of correct type? | |
| 882 for (int i = list.length - 1; i >= 0; i--) { | |
| 883 dynamic element = list[i]; | |
| 884 if (test(element)) return element; | |
| 885 } | |
| 886 if (orElse != null) return orElse(); | |
| 887 throw new StateError("No matching element"); | |
| 888 } | |
| 889 | |
| 890 static dynamic singleWhere(Iterable iterable, bool test(dynamic value)) { | |
| 891 dynamic result = null; | |
| 892 bool foundMatching = false; | |
| 893 for (dynamic element in iterable) { | |
| 894 if (test(element)) { | |
| 895 if (foundMatching) { | |
| 896 throw new StateError("More than one matching element"); | |
| 897 } | |
| 898 result = element; | |
| 899 foundMatching = true; | |
| 900 } | |
| 901 } | |
| 902 if (foundMatching) return result; | |
| 903 throw new StateError("No matching element"); | |
| 904 } | |
| 905 | |
| 906 static dynamic elementAt(Iterable iterable, int index) { | |
| 907 if (index is! int || index < 0) throw new RangeError.value(index); | |
| 908 int remaining = index; | |
| 909 for (dynamic element in iterable) { | |
| 910 if (remaining == 0) return element; | |
| 911 remaining--; | |
| 912 } | |
| 913 throw new RangeError.value(index); | |
| 914 } | |
| 915 | |
| 916 static String join(Iterable iterable, [String separator]) { | |
| 917 StringBuffer buffer = new StringBuffer(); | |
| 918 buffer.writeAll(iterable, separator); | |
| 919 return buffer.toString(); | |
| 920 } | |
| 921 | |
| 922 static String joinList(List list, [String separator]) { | |
| 923 if (list.isEmpty) return ""; | |
| 924 if (list.length == 1) return "${list[0]}"; | |
| 925 StringBuffer buffer = new StringBuffer(); | |
| 926 if (separator.isEmpty) { | |
| 927 for (int i = 0; i < list.length; i++) { | |
| 928 buffer.write(list[i]); | |
| 929 } | |
| 930 } else { | |
| 931 buffer.write(list[0]); | |
| 932 for (int i = 1; i < list.length; i++) { | |
| 933 buffer.write(separator); | |
| 934 buffer.write(list[i]); | |
| 935 } | |
| 936 } | |
| 937 return buffer.toString(); | |
| 938 } | |
| 939 | |
| 940 static String toStringIterable(Iterable iterable, String leftDelimiter, | |
| 941 String rightDelimiter) { | |
| 942 for (int i = 0; i < _toStringList.length; i++) { | |
| 943 if (identical(_toStringList[i], iterable)) { | |
| 944 return '$leftDelimiter...$rightDelimiter'; | |
| 945 } | |
| 946 } | |
| 947 | |
| 948 StringBuffer result = new StringBuffer(); | |
| 949 try { | |
| 950 _toStringList.add(iterable); | |
| 951 result.write(leftDelimiter); | |
| 952 result.writeAll(iterable, ', '); | |
| 953 result.write(rightDelimiter); | |
| 954 } finally { | |
| 955 assert(identical(_toStringList.last, iterable)); | |
| 956 _toStringList.removeLast(); | |
| 957 } | |
| 958 return result.toString(); | |
| 959 } | |
| 960 | |
| 961 static Iterable where(Iterable iterable, bool f(var element)) { | |
| 962 return new WhereIterable(iterable, f); | |
| 963 } | |
| 964 | |
| 965 static Iterable map(Iterable iterable, f(var element)) { | |
| 966 return new MappedIterable(iterable, f); | |
| 967 } | |
| 968 | |
| 969 static Iterable mapList(List list, f(var element)) { | |
| 970 return new MappedListIterable(list, f); | |
| 971 } | |
| 972 | |
| 973 static Iterable expand(Iterable iterable, Iterable f(var element)) { | |
| 974 return new ExpandIterable(iterable, f); | |
| 975 } | |
| 976 | |
| 977 static Iterable takeList(List list, int n) { | |
| 978 // The generic type is currently lost. It will be fixed with mixins. | |
| 979 return new SubListIterable(list, 0, n); | |
| 980 } | |
| 981 | |
| 982 static Iterable takeWhile(Iterable iterable, bool test(var value)) { | |
| 983 // The generic type is currently lost. It will be fixed with mixins. | |
| 984 return new TakeWhileIterable(iterable, test); | |
| 985 } | |
| 986 | |
| 987 static Iterable skipList(List list, int n) { | |
| 988 // The generic type is currently lost. It will be fixed with mixins. | |
| 989 return new SubListIterable(list, n, null); | |
| 990 } | |
| 991 | |
| 992 static Iterable skipWhile(Iterable iterable, bool test(var value)) { | |
| 993 // The generic type is currently lost. It will be fixed with mixins. | |
| 994 return new SkipWhileIterable(iterable, test); | |
| 995 } | |
| 996 | |
| 997 static Iterable reversedList(List list) { | |
| 998 return new ReversedListIterable(list); | |
| 999 } | |
| 1000 | |
| 1001 static void sortList(List list, int compare(a, b)) { | |
| 1002 if (compare == null) compare = Comparable.compare; | |
| 1003 Sort.sort(list, compare); | |
| 1004 } | |
| 1005 | |
| 1006 static void shuffleList(List list, Random random) { | |
| 1007 if (random == null) random = new Random(); | |
| 1008 int length = list.length; | |
| 1009 while (length > 1) { | |
| 1010 int pos = random.nextInt(length); | |
| 1011 length -= 1; | |
| 1012 var tmp = list[length]; | |
| 1013 list[length] = list[pos]; | |
| 1014 list[pos] = tmp; | |
| 1015 } | |
| 1016 } | |
| 1017 | |
| 1018 static int indexOfList(List list, var element, int start) { | |
| 1019 return Lists.indexOf(list, element, start, list.length); | |
| 1020 } | |
| 1021 | |
| 1022 static int lastIndexOfList(List list, var element, int start) { | |
| 1023 if (start == null) start = list.length - 1; | |
| 1024 return Lists.lastIndexOf(list, element, start); | |
| 1025 } | |
| 1026 | |
| 1027 static void _rangeCheck(List list, int start, int end) { | |
| 1028 if (start < 0 || start > list.length) { | |
| 1029 throw new RangeError.range(start, 0, list.length); | |
| 1030 } | |
| 1031 if (end < start || end > list.length) { | |
| 1032 throw new RangeError.range(end, start, list.length); | |
| 1033 } | |
| 1034 } | |
| 1035 | |
| 1036 static Iterable getRangeList(List list, int start, int end) { | |
| 1037 _rangeCheck(list, start, end); | |
| 1038 // The generic type is currently lost. It will be fixed with mixins. | |
| 1039 return new SubListIterable(list, start, end); | |
| 1040 } | |
| 1041 | |
| 1042 static void setRangeList(List list, int start, int end, | |
| 1043 Iterable from, int skipCount) { | |
| 1044 _rangeCheck(list, start, end); | |
| 1045 int length = end - start; | |
| 1046 if (length == 0) return; | |
| 1047 | |
| 1048 if (skipCount < 0) throw new ArgumentError(skipCount); | |
| 1049 | |
| 1050 // TODO(floitsch): Make this accept more. | |
| 1051 List otherList; | |
| 1052 int otherStart; | |
| 1053 if (from is List) { | |
| 1054 otherList = from; | |
| 1055 otherStart = skipCount; | |
| 1056 } else { | |
| 1057 otherList = from.skip(skipCount).toList(growable: false); | |
| 1058 otherStart = 0; | |
| 1059 } | |
| 1060 if (otherStart + length > otherList.length) { | |
| 1061 throw new StateError("Not enough elements"); | |
| 1062 } | |
| 1063 Lists.copy(otherList, otherStart, list, start, length); | |
| 1064 } | |
| 1065 | |
| 1066 static void replaceRangeList(List list, int start, int end, | |
| 1067 Iterable iterable) { | |
| 1068 _rangeCheck(list, start, end); | |
| 1069 if (iterable is! EfficientLength) { | |
| 1070 iterable = iterable.toList(); | |
| 1071 } | |
| 1072 int removeLength = end - start; | |
| 1073 int insertLength = iterable.length; | |
| 1074 if (removeLength >= insertLength) { | |
| 1075 int delta = removeLength - insertLength; | |
| 1076 int insertEnd = start + insertLength; | |
| 1077 int newEnd = list.length - delta; | |
| 1078 list.setRange(start, insertEnd, iterable); | |
| 1079 if (delta != 0) { | |
| 1080 list.setRange(insertEnd, newEnd, list, end); | |
| 1081 list.length = newEnd; | |
| 1082 } | |
| 1083 } else { | |
| 1084 int delta = insertLength - removeLength; | |
| 1085 int newLength = list.length + delta; | |
| 1086 int insertEnd = start + insertLength; // aka. end + delta. | |
| 1087 list.length = newLength; | |
| 1088 list.setRange(insertEnd, newLength, list, end); | |
| 1089 list.setRange(start, insertEnd, iterable); | |
| 1090 } | |
| 1091 } | |
| 1092 | |
| 1093 static void fillRangeList(List list, int start, int end, fillValue) { | |
| 1094 _rangeCheck(list, start, end); | |
| 1095 for (int i = start; i < end; i++) { | |
| 1096 list[i] = fillValue; | |
| 1097 } | |
| 1098 } | |
| 1099 | |
| 1100 static void insertAllList(List list, int index, Iterable iterable) { | |
| 1101 if (index < 0 || index > list.length) { | |
| 1102 throw new RangeError.range(index, 0, list.length); | |
| 1103 } | |
| 1104 if (iterable is! EfficientLength) { | |
| 1105 iterable = iterable.toList(growable: false); | |
| 1106 } | |
| 1107 int insertionLength = iterable.length; | |
| 1108 list.length += insertionLength; | |
| 1109 list.setRange(index + insertionLength, list.length, list, index); | |
| 1110 for (var element in iterable) { | |
| 1111 list[index++] = element; | |
| 1112 } | |
| 1113 } | |
| 1114 | |
| 1115 static void setAllList(List list, int index, Iterable iterable) { | |
| 1116 if (index < 0 || index > list.length) { | |
| 1117 throw new RangeError.range(index, 0, list.length); | |
| 1118 } | |
| 1119 for (var element in iterable) { | |
| 1120 list[index++] = element; | |
| 1121 } | |
| 1122 } | |
| 1123 | |
| 1124 static Map<int, dynamic> asMapList(List l) { | |
| 1125 return new ListMapView(l); | |
| 1126 } | |
| 1127 | |
| 1128 static bool setContainsAll(Set set, Iterable other) { | |
| 1129 for (var element in other) { | |
| 1130 if (!set.contains(element)) return false; | |
| 1131 } | |
| 1132 return true; | |
| 1133 } | |
| 1134 | |
| 1135 static Set setIntersection(Set set, Set other, Set result) { | |
| 1136 Set smaller; | |
| 1137 Set larger; | |
| 1138 if (set.length < other.length) { | |
| 1139 smaller = set; | |
| 1140 larger = other; | |
| 1141 } else { | |
| 1142 smaller = other; | |
| 1143 larger = set; | |
| 1144 } | |
| 1145 for (var element in smaller) { | |
| 1146 if (larger.contains(element)) { | |
| 1147 result.add(element); | |
| 1148 } | |
| 1149 } | |
| 1150 return result; | |
| 1151 } | |
| 1152 | |
| 1153 static Set setUnion(Set set, Set other, Set result) { | |
| 1154 result.addAll(set); | |
| 1155 result.addAll(other); | |
| 1156 return result; | |
| 1157 } | |
| 1158 | |
| 1159 static Set setDifference(Set set, Set other, Set result) { | |
| 1160 for (var element in set) { | |
| 1161 if (!other.contains(element)) { | |
| 1162 result.add(element); | |
| 1163 } | |
| 1164 } | |
| 1165 return result; | |
| 1166 } | |
| 1167 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 133273011:
Revert "Rename internal library dart:_collection-dev to dart:_internal." (Closed)
Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart