1 /* 2 * Copyright (c) 2013, 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.util.stream; 26 27 import java.util.Arrays; 28 import java.util.LongSummaryStatistics; 29 import java.util.Objects; 30 import java.util.OptionalDouble; 31 import java.util.OptionalLong; 32 import java.util.PrimitiveIterator; 33 import java.util.Spliterator; 34 import java.util.Spliterators; 35 import java.util.function.BiConsumer; 36 import java.util.function.Function; 37 import java.util.function.LongBinaryOperator; 38 import java.util.function.LongConsumer; 39 import java.util.function.LongFunction; 40 import java.util.function.LongPredicate; 41 import java.util.function.LongSupplier; 42 import java.util.function.LongToDoubleFunction; 43 import java.util.function.LongToIntFunction; 44 import java.util.function.LongUnaryOperator; 45 import java.util.function.ObjLongConsumer; 46 import java.util.function.Supplier; 47 48 /** 49 * A sequence of primitive long-valued elements supporting sequential and parallel 50 * aggregate operations. This is the {@code long} primitive specialization of 51 * {@link Stream}. 52 * 53 * <p>The following example illustrates an aggregate operation using 54 * {@link Stream} and {@link LongStream}, computing the sum of the weights of the 55 * red widgets: 56 * 57 * <pre>{@code 58 * long sum = widgets.stream() 59 * .filter(w -> w.getColor() == RED) 60 * .mapToLong(w -> w.getWeight()) 61 * .sum(); 62 * }</pre> 63 * 64 * See the class documentation for {@link Stream} and the package documentation 65 * for <a href="package-summary.html">java.util.stream</a> for additional 66 * specification of streams, stream operations, stream pipelines, and 67 * parallelism. 68 * 69 * @since 1.8 70 * @see Stream 71 * @see <a href="package-summary.html">java.util.stream</a> 72 */ 73 public interface LongStream extends BaseStream<Long, LongStream> { 74 75 /** 76 * Returns a stream consisting of the elements of this stream that match 77 * the given predicate. 78 * 79 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 80 * operation</a>. 81 * 82 * @param predicate a <a href="package-summary.html#NonInterference">non-interfering</a>, 83 * <a href="package-summary.html#Statelessness">stateless</a> 84 * predicate to apply to each element to determine if it 85 * should be included 86 * @return the new stream 87 */ filter(LongPredicate predicate)88 LongStream filter(LongPredicate predicate); 89 90 /** 91 * Returns a stream consisting of the results of applying the given 92 * function to the elements of this stream. 93 * 94 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 95 * operation</a>. 96 * 97 * @param mapper a <a href="package-summary.html#NonInterference">non-interfering</a>, 98 * <a href="package-summary.html#Statelessness">stateless</a> 99 * function to apply to each element 100 * @return the new stream 101 */ map(LongUnaryOperator mapper)102 LongStream map(LongUnaryOperator mapper); 103 104 /** 105 * Returns an object-valued {@code Stream} consisting of the results of 106 * applying the given function to the elements of this stream. 107 * 108 * <p>This is an <a href="package-summary.html#StreamOps"> 109 * intermediate operation</a>. 110 * 111 * @param <U> the element type of the new stream 112 * @param mapper a <a href="package-summary.html#NonInterference">non-interfering</a>, 113 * <a href="package-summary.html#Statelessness">stateless</a> 114 * function to apply to each element 115 * @return the new stream 116 */ mapToObj(LongFunction<? extends U> mapper)117 <U> Stream<U> mapToObj(LongFunction<? extends U> mapper); 118 119 /** 120 * Returns an {@code IntStream} consisting of the results of applying the 121 * given function to the elements of this stream. 122 * 123 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 124 * operation</a>. 125 * 126 * @param mapper a <a href="package-summary.html#NonInterference">non-interfering</a>, 127 * <a href="package-summary.html#Statelessness">stateless</a> 128 * function to apply to each element 129 * @return the new stream 130 */ mapToInt(LongToIntFunction mapper)131 IntStream mapToInt(LongToIntFunction mapper); 132 133 /** 134 * Returns a {@code DoubleStream} consisting of the results of applying the 135 * given function to the elements of this stream. 136 * 137 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 138 * operation</a>. 139 * 140 * @param mapper a <a href="package-summary.html#NonInterference">non-interfering</a>, 141 * <a href="package-summary.html#Statelessness">stateless</a> 142 * function to apply to each element 143 * @return the new stream 144 */ mapToDouble(LongToDoubleFunction mapper)145 DoubleStream mapToDouble(LongToDoubleFunction mapper); 146 147 /** 148 * Returns a stream consisting of the results of replacing each element of 149 * this stream with the contents of a mapped stream produced by applying 150 * the provided mapping function to each element. Each mapped stream is 151 * {@link java.util.stream.BaseStream#close() closed} after its contents 152 * have been placed into this stream. (If a mapped stream is {@code null} 153 * an empty stream is used, instead.) 154 * 155 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 156 * operation</a>. 157 * 158 * @param mapper a <a href="package-summary.html#NonInterference">non-interfering</a>, 159 * <a href="package-summary.html#Statelessness">stateless</a> 160 * function to apply to each element which produces a 161 * {@code LongStream} of new values 162 * @return the new stream 163 * @see Stream#flatMap(Function) 164 */ flatMap(LongFunction<? extends LongStream> mapper)165 LongStream flatMap(LongFunction<? extends LongStream> mapper); 166 167 /** 168 * Returns a stream consisting of the results of replacing each element of 169 * this stream with multiple elements, specifically zero or more elements. 170 * Replacement is performed by applying the provided mapping function to each 171 * element in conjunction with a {@linkplain LongConsumer consumer} argument 172 * that accepts replacement elements. The mapping function calls the consumer 173 * zero or more times to provide the replacement elements. 174 * 175 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 176 * operation</a>. 177 * 178 * <p>If the {@linkplain LongConsumer consumer} argument is used outside the scope of 179 * its application to the mapping function, the results are undefined. 180 * 181 * @implSpec 182 * The default implementation invokes {@link #flatMap flatMap} on this stream, 183 * passing a function that behaves as follows. First, it calls the mapper function 184 * with a {@code LongConsumer} that accumulates replacement elements into a newly created 185 * internal buffer. When the mapper function returns, it creates a {@code LongStream} from the 186 * internal buffer. Finally, it returns this stream to {@code flatMap}. 187 * 188 * @param mapper a <a href="package-summary.html#NonInterference">non-interfering</a>, 189 * <a href="package-summary.html#Statelessness">stateless</a> 190 * function that generates replacement elements 191 * @return the new stream 192 * @see Stream#mapMulti Stream.mapMulti 193 * @since 16 194 */ mapMulti(LongMapMultiConsumer mapper)195 default LongStream mapMulti(LongMapMultiConsumer mapper) { 196 Objects.requireNonNull(mapper); 197 return flatMap(e -> { 198 SpinedBuffer.OfLong buffer = new SpinedBuffer.OfLong(); 199 mapper.accept(e, buffer); 200 return StreamSupport.longStream(buffer.spliterator(), false); 201 }); 202 } 203 204 /** 205 * Returns a stream consisting of the distinct elements of this stream. 206 * 207 * <p>This is a <a href="package-summary.html#StreamOps">stateful 208 * intermediate operation</a>. 209 * 210 * @return the new stream 211 */ distinct()212 LongStream distinct(); 213 214 /** 215 * Returns a stream consisting of the elements of this stream in sorted 216 * order. 217 * 218 * <p>This is a <a href="package-summary.html#StreamOps">stateful 219 * intermediate operation</a>. 220 * 221 * @return the new stream 222 */ sorted()223 LongStream sorted(); 224 225 /** 226 * Returns a stream consisting of the elements of this stream, additionally 227 * performing the provided action on each element as elements are consumed 228 * from the resulting stream. 229 * 230 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 231 * operation</a>. 232 * 233 * <p>For parallel stream pipelines, the action may be called at 234 * whatever time and in whatever thread the element is made available by the 235 * upstream operation. If the action modifies shared state, 236 * it is responsible for providing the required synchronization. 237 * 238 * @apiNote This method exists mainly to support debugging, where you want 239 * to see the elements as they flow past a certain point in a pipeline: 240 * <pre>{@code 241 * LongStream.of(1, 2, 3, 4) 242 * .filter(e -> e > 2) 243 * .peek(e -> System.out.println("Filtered value: " + e)) 244 * .map(e -> e * e) 245 * .peek(e -> System.out.println("Mapped value: " + e)) 246 * .sum(); 247 * }</pre> 248 * 249 * <p>In cases where the stream implementation is able to optimize away the 250 * production of some or all the elements (such as with short-circuiting 251 * operations like {@code findFirst}, or in the example described in 252 * {@link #count}), the action will not be invoked for those elements. 253 * 254 * @param action a <a href="package-summary.html#NonInterference"> 255 * non-interfering</a> action to perform on the elements as 256 * they are consumed from the stream 257 * @return the new stream 258 */ peek(LongConsumer action)259 LongStream peek(LongConsumer action); 260 261 /** 262 * Returns a stream consisting of the elements of this stream, truncated 263 * to be no longer than {@code maxSize} in length. 264 * 265 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 266 * stateful intermediate operation</a>. 267 * 268 * @apiNote 269 * While {@code limit()} is generally a cheap operation on sequential 270 * stream pipelines, it can be quite expensive on ordered parallel pipelines, 271 * especially for large values of {@code maxSize}, since {@code limit(n)} 272 * is constrained to return not just any <em>n</em> elements, but the 273 * <em>first n</em> elements in the encounter order. Using an unordered 274 * stream source (such as {@link #generate(LongSupplier)}) or removing the 275 * ordering constraint with {@link #unordered()} may result in significant 276 * speedups of {@code limit()} in parallel pipelines, if the semantics of 277 * your situation permit. If consistency with encounter order is required, 278 * and you are experiencing poor performance or memory utilization with 279 * {@code limit()} in parallel pipelines, switching to sequential execution 280 * with {@link #sequential()} may improve performance. 281 * 282 * @param maxSize the number of elements the stream should be limited to 283 * @return the new stream 284 * @throws IllegalArgumentException if {@code maxSize} is negative 285 */ limit(long maxSize)286 LongStream limit(long maxSize); 287 288 /** 289 * Returns a stream consisting of the remaining elements of this stream 290 * after discarding the first {@code n} elements of the stream. 291 * If this stream contains fewer than {@code n} elements then an 292 * empty stream will be returned. 293 * 294 * <p>This is a <a href="package-summary.html#StreamOps">stateful 295 * intermediate operation</a>. 296 * 297 * @apiNote 298 * While {@code skip()} is generally a cheap operation on sequential 299 * stream pipelines, it can be quite expensive on ordered parallel pipelines, 300 * especially for large values of {@code n}, since {@code skip(n)} 301 * is constrained to skip not just any <em>n</em> elements, but the 302 * <em>first n</em> elements in the encounter order. Using an unordered 303 * stream source (such as {@link #generate(LongSupplier)}) or removing the 304 * ordering constraint with {@link #unordered()} may result in significant 305 * speedups of {@code skip()} in parallel pipelines, if the semantics of 306 * your situation permit. If consistency with encounter order is required, 307 * and you are experiencing poor performance or memory utilization with 308 * {@code skip()} in parallel pipelines, switching to sequential execution 309 * with {@link #sequential()} may improve performance. 310 * 311 * @param n the number of leading elements to skip 312 * @return the new stream 313 * @throws IllegalArgumentException if {@code n} is negative 314 */ skip(long n)315 LongStream skip(long n); 316 317 /** 318 * Returns, if this stream is ordered, a stream consisting of the longest 319 * prefix of elements taken from this stream that match the given predicate. 320 * Otherwise returns, if this stream is unordered, a stream consisting of a 321 * subset of elements taken from this stream that match the given predicate. 322 * 323 * <p>If this stream is ordered then the longest prefix is a contiguous 324 * sequence of elements of this stream that match the given predicate. The 325 * first element of the sequence is the first element of this stream, and 326 * the element immediately following the last element of the sequence does 327 * not match the given predicate. 328 * 329 * <p>If this stream is unordered, and some (but not all) elements of this 330 * stream match the given predicate, then the behavior of this operation is 331 * nondeterministic; it is free to take any subset of matching elements 332 * (which includes the empty set). 333 * 334 * <p>Independent of whether this stream is ordered or unordered if all 335 * elements of this stream match the given predicate then this operation 336 * takes all elements (the result is the same as the input), or if no 337 * elements of the stream match the given predicate then no elements are 338 * taken (the result is an empty stream). 339 * 340 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 341 * stateful intermediate operation</a>. 342 * 343 * @implSpec 344 * The default implementation obtains the {@link #spliterator() spliterator} 345 * of this stream, wraps that spliterator so as to support the semantics 346 * of this operation on traversal, and returns a new stream associated with 347 * the wrapped spliterator. The returned stream preserves the execution 348 * characteristics of this stream (namely parallel or sequential execution 349 * as per {@link #isParallel()}) but the wrapped spliterator may choose to 350 * not support splitting. When the returned stream is closed, the close 351 * handlers for both the returned and this stream are invoked. 352 * 353 * @apiNote 354 * While {@code takeWhile()} is generally a cheap operation on sequential 355 * stream pipelines, it can be quite expensive on ordered parallel 356 * pipelines, since the operation is constrained to return not just any 357 * valid prefix, but the longest prefix of elements in the encounter order. 358 * Using an unordered stream source (such as 359 * {@link #generate(LongSupplier)}) or removing the ordering constraint with 360 * {@link #unordered()} may result in significant speedups of 361 * {@code takeWhile()} in parallel pipelines, if the semantics of your 362 * situation permit. If consistency with encounter order is required, and 363 * you are experiencing poor performance or memory utilization with 364 * {@code takeWhile()} in parallel pipelines, switching to sequential 365 * execution with {@link #sequential()} may improve performance. 366 * 367 * @param predicate a <a href="package-summary.html#NonInterference">non-interfering</a>, 368 * <a href="package-summary.html#Statelessness">stateless</a> 369 * predicate to apply to elements to determine the longest 370 * prefix of elements. 371 * @return the new stream 372 * @since 9 373 */ takeWhile(LongPredicate predicate)374 default LongStream takeWhile(LongPredicate predicate) { 375 Objects.requireNonNull(predicate); 376 // Reuses the unordered spliterator, which, when encounter is present, 377 // is safe to use as long as it configured not to split 378 return StreamSupport.longStream( 379 new WhileOps.UnorderedWhileSpliterator.OfLong.Taking(spliterator(), true, predicate), 380 isParallel()).onClose(this::close); 381 } 382 383 /** 384 * Returns, if this stream is ordered, a stream consisting of the remaining 385 * elements of this stream after dropping the longest prefix of elements 386 * that match the given predicate. Otherwise returns, if this stream is 387 * unordered, a stream consisting of the remaining elements of this stream 388 * after dropping a subset of elements that match the given predicate. 389 * 390 * <p>If this stream is ordered then the longest prefix is a contiguous 391 * sequence of elements of this stream that match the given predicate. The 392 * first element of the sequence is the first element of this stream, and 393 * the element immediately following the last element of the sequence does 394 * not match the given predicate. 395 * 396 * <p>If this stream is unordered, and some (but not all) elements of this 397 * stream match the given predicate, then the behavior of this operation is 398 * nondeterministic; it is free to drop any subset of matching elements 399 * (which includes the empty set). 400 * 401 * <p>Independent of whether this stream is ordered or unordered if all 402 * elements of this stream match the given predicate then this operation 403 * drops all elements (the result is an empty stream), or if no elements of 404 * the stream match the given predicate then no elements are dropped (the 405 * result is the same as the input). 406 * 407 * <p>This is a <a href="package-summary.html#StreamOps">stateful 408 * intermediate operation</a>. 409 * 410 * @implSpec 411 * The default implementation obtains the {@link #spliterator() spliterator} 412 * of this stream, wraps that spliterator so as to support the semantics 413 * of this operation on traversal, and returns a new stream associated with 414 * the wrapped spliterator. The returned stream preserves the execution 415 * characteristics of this stream (namely parallel or sequential execution 416 * as per {@link #isParallel()}) but the wrapped spliterator may choose to 417 * not support splitting. When the returned stream is closed, the close 418 * handlers for both the returned and this stream are invoked. 419 * 420 * @apiNote 421 * While {@code dropWhile()} is generally a cheap operation on sequential 422 * stream pipelines, it can be quite expensive on ordered parallel 423 * pipelines, since the operation is constrained to return not just any 424 * valid prefix, but the longest prefix of elements in the encounter order. 425 * Using an unordered stream source (such as 426 * {@link #generate(LongSupplier)}) or removing the ordering constraint with 427 * {@link #unordered()} may result in significant speedups of 428 * {@code dropWhile()} in parallel pipelines, if the semantics of your 429 * situation permit. If consistency with encounter order is required, and 430 * you are experiencing poor performance or memory utilization with 431 * {@code dropWhile()} in parallel pipelines, switching to sequential 432 * execution with {@link #sequential()} may improve performance. 433 * 434 * @param predicate a <a href="package-summary.html#NonInterference">non-interfering</a>, 435 * <a href="package-summary.html#Statelessness">stateless</a> 436 * predicate to apply to elements to determine the longest 437 * prefix of elements. 438 * @return the new stream 439 * @since 9 440 */ dropWhile(LongPredicate predicate)441 default LongStream dropWhile(LongPredicate predicate) { 442 Objects.requireNonNull(predicate); 443 // Reuses the unordered spliterator, which, when encounter is present, 444 // is safe to use as long as it configured not to split 445 return StreamSupport.longStream( 446 new WhileOps.UnorderedWhileSpliterator.OfLong.Dropping(spliterator(), true, predicate), 447 isParallel()).onClose(this::close); 448 } 449 450 /** 451 * Performs an action for each element of this stream. 452 * 453 * <p>This is a <a href="package-summary.html#StreamOps">terminal 454 * operation</a>. 455 * 456 * <p>For parallel stream pipelines, this operation does <em>not</em> 457 * guarantee to respect the encounter order of the stream, as doing so 458 * would sacrifice the benefit of parallelism. For any given element, the 459 * action may be performed at whatever time and in whatever thread the 460 * library chooses. If the action accesses shared state, it is 461 * responsible for providing the required synchronization. 462 * 463 * @param action a <a href="package-summary.html#NonInterference"> 464 * non-interfering</a> action to perform on the elements 465 */ forEach(LongConsumer action)466 void forEach(LongConsumer action); 467 468 /** 469 * Performs an action for each element of this stream, guaranteeing that 470 * each element is processed in encounter order for streams that have a 471 * defined encounter order. 472 * 473 * <p>This is a <a href="package-summary.html#StreamOps">terminal 474 * operation</a>. 475 * 476 * @param action a <a href="package-summary.html#NonInterference"> 477 * non-interfering</a> action to perform on the elements 478 * @see #forEach(LongConsumer) 479 */ forEachOrdered(LongConsumer action)480 void forEachOrdered(LongConsumer action); 481 482 /** 483 * Returns an array containing the elements of this stream. 484 * 485 * <p>This is a <a href="package-summary.html#StreamOps">terminal 486 * operation</a>. 487 * 488 * @return an array containing the elements of this stream 489 */ toArray()490 long[] toArray(); 491 492 /** 493 * Performs a <a href="package-summary.html#Reduction">reduction</a> on the 494 * elements of this stream, using the provided identity value and an 495 * <a href="package-summary.html#Associativity">associative</a> 496 * accumulation function, and returns the reduced value. This is equivalent 497 * to: 498 * <pre>{@code 499 * long result = identity; 500 * for (long element : this stream) 501 * result = accumulator.applyAsLong(result, element) 502 * return result; 503 * }</pre> 504 * 505 * but is not constrained to execute sequentially. 506 * 507 * <p>The {@code identity} value must be an identity for the accumulator 508 * function. This means that for all {@code x}, 509 * {@code accumulator.apply(identity, x)} is equal to {@code x}. 510 * The {@code accumulator} function must be an 511 * <a href="package-summary.html#Associativity">associative</a> function. 512 * 513 * <p>This is a <a href="package-summary.html#StreamOps">terminal 514 * operation</a>. 515 * 516 * @apiNote Sum, min, max, and average are all special cases of reduction. 517 * Summing a stream of numbers can be expressed as: 518 * 519 * <pre>{@code 520 * long sum = integers.reduce(0, (a, b) -> a+b); 521 * }</pre> 522 * 523 * or more compactly: 524 * 525 * <pre>{@code 526 * long sum = integers.reduce(0, Long::sum); 527 * }</pre> 528 * 529 * <p>While this may seem a more roundabout way to perform an aggregation 530 * compared to simply mutating a running total in a loop, reduction 531 * operations parallelize more gracefully, without needing additional 532 * synchronization and with greatly reduced risk of data races. 533 * 534 * @param identity the identity value for the accumulating function 535 * @param op an <a href="package-summary.html#Associativity">associative</a>, 536 * <a href="package-summary.html#NonInterference">non-interfering</a>, 537 * <a href="package-summary.html#Statelessness">stateless</a> 538 * function for combining two values 539 * @return the result of the reduction 540 * @see #sum() 541 * @see #min() 542 * @see #max() 543 * @see #average() 544 */ reduce(long identity, LongBinaryOperator op)545 long reduce(long identity, LongBinaryOperator op); 546 547 /** 548 * Performs a <a href="package-summary.html#Reduction">reduction</a> on the 549 * elements of this stream, using an 550 * <a href="package-summary.html#Associativity">associative</a> accumulation 551 * function, and returns an {@code OptionalLong} describing the reduced value, 552 * if any. This is equivalent to: 553 * <pre>{@code 554 * boolean foundAny = false; 555 * long result = null; 556 * for (long element : this stream) { 557 * if (!foundAny) { 558 * foundAny = true; 559 * result = element; 560 * } 561 * else 562 * result = accumulator.applyAsLong(result, element); 563 * } 564 * return foundAny ? OptionalLong.of(result) : OptionalLong.empty(); 565 * }</pre> 566 * 567 * but is not constrained to execute sequentially. 568 * 569 * <p>The {@code accumulator} function must be an 570 * <a href="package-summary.html#Associativity">associative</a> function. 571 * 572 * <p>This is a <a href="package-summary.html#StreamOps">terminal 573 * operation</a>. 574 * 575 * @param op an <a href="package-summary.html#Associativity">associative</a>, 576 * <a href="package-summary.html#NonInterference">non-interfering</a>, 577 * <a href="package-summary.html#Statelessness">stateless</a> 578 * function for combining two values 579 * @return the result of the reduction 580 * @see #reduce(long, LongBinaryOperator) 581 */ reduce(LongBinaryOperator op)582 OptionalLong reduce(LongBinaryOperator op); 583 584 /** 585 * Performs a <a href="package-summary.html#MutableReduction">mutable 586 * reduction</a> operation on the elements of this stream. A mutable 587 * reduction is one in which the reduced value is a mutable result container, 588 * such as an {@code ArrayList}, and elements are incorporated by updating 589 * the state of the result rather than by replacing the result. This 590 * produces a result equivalent to: 591 * <pre>{@code 592 * R result = supplier.get(); 593 * for (long element : this stream) 594 * accumulator.accept(result, element); 595 * return result; 596 * }</pre> 597 * 598 * <p>Like {@link #reduce(long, LongBinaryOperator)}, {@code collect} operations 599 * can be parallelized without requiring additional synchronization. 600 * 601 * <p>This is a <a href="package-summary.html#StreamOps">terminal 602 * operation</a>. 603 * 604 * @param <R> the type of the mutable result container 605 * @param supplier a function that creates a new mutable result container. 606 * For a parallel execution, this function may be called 607 * multiple times and must return a fresh value each time. 608 * @param accumulator an <a href="package-summary.html#Associativity">associative</a>, 609 * <a href="package-summary.html#NonInterference">non-interfering</a>, 610 * <a href="package-summary.html#Statelessness">stateless</a> 611 * function that must fold an element into a result 612 * container. 613 * @param combiner an <a href="package-summary.html#Associativity">associative</a>, 614 * <a href="package-summary.html#NonInterference">non-interfering</a>, 615 * <a href="package-summary.html#Statelessness">stateless</a> 616 * function that accepts two partial result containers 617 * and merges them, which must be compatible with the 618 * accumulator function. The combiner function must fold 619 * the elements from the second result container into the 620 * first result container. 621 * @return the result of the reduction 622 * @see Stream#collect(Supplier, BiConsumer, BiConsumer) 623 */ collect(Supplier<R> supplier, ObjLongConsumer<R> accumulator, BiConsumer<R, R> combiner)624 <R> R collect(Supplier<R> supplier, 625 ObjLongConsumer<R> accumulator, 626 BiConsumer<R, R> combiner); 627 628 /** 629 * Returns the sum of elements in this stream. This is a special case 630 * of a <a href="package-summary.html#Reduction">reduction</a> 631 * and is equivalent to: 632 * <pre>{@code 633 * return reduce(0, Long::sum); 634 * }</pre> 635 * 636 * <p>This is a <a href="package-summary.html#StreamOps">terminal 637 * operation</a>. 638 * 639 * @return the sum of elements in this stream 640 */ sum()641 long sum(); 642 643 /** 644 * Returns an {@code OptionalLong} describing the minimum element of this 645 * stream, or an empty optional if this stream is empty. This is a special 646 * case of a <a href="package-summary.html#Reduction">reduction</a> 647 * and is equivalent to: 648 * <pre>{@code 649 * return reduce(Long::min); 650 * }</pre> 651 * 652 * <p>This is a <a href="package-summary.html#StreamOps">terminal operation</a>. 653 * 654 * @return an {@code OptionalLong} containing the minimum element of this 655 * stream, or an empty {@code OptionalLong} if the stream is empty 656 */ min()657 OptionalLong min(); 658 659 /** 660 * Returns an {@code OptionalLong} describing the maximum element of this 661 * stream, or an empty optional if this stream is empty. This is a special 662 * case of a <a href="package-summary.html#Reduction">reduction</a> 663 * and is equivalent to: 664 * <pre>{@code 665 * return reduce(Long::max); 666 * }</pre> 667 * 668 * <p>This is a <a href="package-summary.html#StreamOps">terminal 669 * operation</a>. 670 * 671 * @return an {@code OptionalLong} containing the maximum element of this 672 * stream, or an empty {@code OptionalLong} if the stream is empty 673 */ max()674 OptionalLong max(); 675 676 /** 677 * Returns the count of elements in this stream. This is a special case of 678 * a <a href="package-summary.html#Reduction">reduction</a> and is 679 * equivalent to: 680 * <pre>{@code 681 * return map(e -> 1L).sum(); 682 * }</pre> 683 * 684 * <p>This is a <a href="package-summary.html#StreamOps">terminal operation</a>. 685 * 686 * @apiNote 687 * An implementation may choose to not execute the stream pipeline (either 688 * sequentially or in parallel) if it is capable of computing the count 689 * directly from the stream source. In such cases no source elements will 690 * be traversed and no intermediate operations will be evaluated. 691 * Behavioral parameters with side-effects, which are strongly discouraged 692 * except for harmless cases such as debugging, may be affected. For 693 * example, consider the following stream: 694 * <pre>{@code 695 * LongStream s = LongStream.of(1, 2, 3, 4); 696 * long count = s.peek(System.out::println).count(); 697 * }</pre> 698 * The number of elements covered by the stream source is known and the 699 * intermediate operation, {@code peek}, does not inject into or remove 700 * elements from the stream (as may be the case for {@code flatMap} or 701 * {@code filter} operations). Thus the count is 4 and there is no need to 702 * execute the pipeline and, as a side-effect, print out the elements. 703 * 704 * @return the count of elements in this stream 705 */ count()706 long count(); 707 708 /** 709 * Returns an {@code OptionalDouble} describing the arithmetic mean of elements of 710 * this stream, or an empty optional if this stream is empty. This is a 711 * special case of a 712 * <a href="package-summary.html#Reduction">reduction</a>. 713 * 714 * <p>This is a <a href="package-summary.html#StreamOps">terminal 715 * operation</a>. 716 * 717 * @return an {@code OptionalDouble} containing the average element of this 718 * stream, or an empty optional if the stream is empty 719 */ average()720 OptionalDouble average(); 721 722 /** 723 * Returns a {@code LongSummaryStatistics} describing various summary data 724 * about the elements of this stream. This is a special case of a 725 * <a href="package-summary.html#Reduction">reduction</a>. 726 * 727 * <p>This is a <a href="package-summary.html#StreamOps">terminal 728 * operation</a>. 729 * 730 * @return a {@code LongSummaryStatistics} describing various summary data 731 * about the elements of this stream 732 */ summaryStatistics()733 LongSummaryStatistics summaryStatistics(); 734 735 /** 736 * Returns whether any elements of this stream match the provided 737 * predicate. May not evaluate the predicate on all elements if not 738 * necessary for determining the result. If the stream is empty then 739 * {@code false} is returned and the predicate is not evaluated. 740 * 741 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 742 * terminal operation</a>. 743 * 744 * @apiNote 745 * This method evaluates the <em>existential quantification</em> of the 746 * predicate over the elements of the stream (for some x P(x)). 747 * 748 * @param predicate a <a href="package-summary.html#NonInterference">non-interfering</a>, 749 * <a href="package-summary.html#Statelessness">stateless</a> 750 * predicate to apply to elements of this stream 751 * @return {@code true} if any elements of the stream match the provided 752 * predicate, otherwise {@code false} 753 */ 754 boolean anyMatch(LongPredicate predicate); 755 756 /** 757 * Returns whether all elements of this stream match the provided predicate. 758 * May not evaluate the predicate on all elements if not necessary for 759 * determining the result. If the stream is empty then {@code true} is 760 * returned and the predicate is not evaluated. 761 * 762 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 763 * terminal operation</a>. 764 * 765 * @apiNote 766 * This method evaluates the <em>universal quantification</em> of the 767 * predicate over the elements of the stream (for all x P(x)). If the 768 * stream is empty, the quantification is said to be <em>vacuously 769 * satisfied</em> and is always {@code true} (regardless of P(x)). 770 * 771 * @param predicate a <a href="package-summary.html#NonInterference">non-interfering</a>, 772 * <a href="package-summary.html#Statelessness">stateless</a> 773 * predicate to apply to elements of this stream 774 * @return {@code true} if either all elements of the stream match the 775 * provided predicate or the stream is empty, otherwise {@code false} 776 */ 777 boolean allMatch(LongPredicate predicate); 778 779 /** 780 * Returns whether no elements of this stream match the provided predicate. 781 * May not evaluate the predicate on all elements if not necessary for 782 * determining the result. If the stream is empty then {@code true} is 783 * returned and the predicate is not evaluated. 784 * 785 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 786 * terminal operation</a>. 787 * 788 * @apiNote 789 * This method evaluates the <em>universal quantification</em> of the 790 * negated predicate over the elements of the stream (for all x ~P(x)). If 791 * the stream is empty, the quantification is said to be vacuously satisfied 792 * and is always {@code true}, regardless of P(x). 793 * 794 * @param predicate a <a href="package-summary.html#NonInterference">non-interfering</a>, 795 * <a href="package-summary.html#Statelessness">stateless</a> 796 * predicate to apply to elements of this stream 797 * @return {@code true} if either no elements of the stream match the 798 * provided predicate or the stream is empty, otherwise {@code false} 799 */ 800 boolean noneMatch(LongPredicate predicate); 801 802 /** 803 * Returns an {@link OptionalLong} describing the first element of this 804 * stream, or an empty {@code OptionalLong} if the stream is empty. If the 805 * stream has no encounter order, then any element may be returned. 806 * 807 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 808 * terminal operation</a>. 809 * 810 * @return an {@code OptionalLong} describing the first element of this 811 * stream, or an empty {@code OptionalLong} if the stream is empty 812 */ findFirst()813 OptionalLong findFirst(); 814 815 /** 816 * Returns an {@link OptionalLong} describing some element of the stream, or 817 * an empty {@code OptionalLong} if the stream is empty. 818 * 819 * <p>This is a <a href="package-summary.html#StreamOps">short-circuiting 820 * terminal operation</a>. 821 * 822 * <p>The behavior of this operation is explicitly nondeterministic; it is 823 * free to select any element in the stream. This is to allow for maximal 824 * performance in parallel operations; the cost is that multiple invocations 825 * on the same source may not return the same result. (If a stable result 826 * is desired, use {@link #findFirst()} instead.) 827 * 828 * @return an {@code OptionalLong} describing some element of this stream, 829 * or an empty {@code OptionalLong} if the stream is empty 830 * @see #findFirst() 831 */ findAny()832 OptionalLong findAny(); 833 834 /** 835 * Returns a {@code DoubleStream} consisting of the elements of this stream, 836 * converted to {@code double}. 837 * 838 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 839 * operation</a>. 840 * 841 * @return a {@code DoubleStream} consisting of the elements of this stream, 842 * converted to {@code double} 843 */ asDoubleStream()844 DoubleStream asDoubleStream(); 845 846 /** 847 * Returns a {@code Stream} consisting of the elements of this stream, 848 * each boxed to a {@code Long}. 849 * 850 * <p>This is an <a href="package-summary.html#StreamOps">intermediate 851 * operation</a>. 852 * 853 * @return a {@code Stream} consistent of the elements of this stream, 854 * each boxed to {@code Long} 855 */ boxed()856 Stream<Long> boxed(); 857 858 @Override sequential()859 LongStream sequential(); 860 861 @Override parallel()862 LongStream parallel(); 863 864 @Override iterator()865 PrimitiveIterator.OfLong iterator(); 866 867 @Override spliterator()868 Spliterator.OfLong spliterator(); 869 870 // Static factories 871 872 /** 873 * Returns a builder for a {@code LongStream}. 874 * 875 * @return a stream builder 876 */ builder()877 public static Builder builder() { 878 return new Streams.LongStreamBuilderImpl(); 879 } 880 881 /** 882 * Returns an empty sequential {@code LongStream}. 883 * 884 * @return an empty sequential stream 885 */ empty()886 public static LongStream empty() { 887 return StreamSupport.longStream(Spliterators.emptyLongSpliterator(), false); 888 } 889 890 /** 891 * Returns a sequential {@code LongStream} containing a single element. 892 * 893 * @param t the single element 894 * @return a singleton sequential stream 895 */ of(long t)896 public static LongStream of(long t) { 897 return StreamSupport.longStream(new Streams.LongStreamBuilderImpl(t), false); 898 } 899 900 /** 901 * Returns a sequential ordered stream whose elements are the specified values. 902 * 903 * @param values the elements of the new stream 904 * @return the new stream 905 */ of(long... values)906 public static LongStream of(long... values) { 907 return Arrays.stream(values); 908 } 909 910 /** 911 * Returns an infinite sequential ordered {@code LongStream} produced by iterative 912 * application of a function {@code f} to an initial element {@code seed}, 913 * producing a {@code Stream} consisting of {@code seed}, {@code f(seed)}, 914 * {@code f(f(seed))}, etc. 915 * 916 * <p>The first element (position {@code 0}) in the {@code LongStream} will 917 * be the provided {@code seed}. For {@code n > 0}, the element at position 918 * {@code n}, will be the result of applying the function {@code f} to the 919 * element at position {@code n - 1}. 920 * 921 * <p>The action of applying {@code f} for one element 922 * <a href="../concurrent/package-summary.html#MemoryVisibility"><i>happens-before</i></a> 923 * the action of applying {@code f} for subsequent elements. For any given 924 * element the action may be performed in whatever thread the library 925 * chooses. 926 * 927 * @param seed the initial element 928 * @param f a function to be applied to the previous element to produce 929 * a new element 930 * @return a new sequential {@code LongStream} 931 */ iterate(final long seed, final LongUnaryOperator f)932 public static LongStream iterate(final long seed, final LongUnaryOperator f) { 933 Objects.requireNonNull(f); 934 Spliterator.OfLong spliterator = new Spliterators.AbstractLongSpliterator(Long.MAX_VALUE, 935 Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL) { 936 long prev; 937 boolean started; 938 939 @Override 940 public boolean tryAdvance(LongConsumer action) { 941 Objects.requireNonNull(action); 942 long t; 943 if (started) 944 t = f.applyAsLong(prev); 945 else { 946 t = seed; 947 started = true; 948 } 949 action.accept(prev = t); 950 return true; 951 } 952 }; 953 return StreamSupport.longStream(spliterator, false); 954 } 955 956 /** 957 * Returns a sequential ordered {@code LongStream} produced by iterative 958 * application of the given {@code next} function to an initial element, 959 * conditioned on satisfying the given {@code hasNext} predicate. The 960 * stream terminates as soon as the {@code hasNext} predicate returns false. 961 * 962 * <p>{@code LongStream.iterate} should produce the same sequence of elements as 963 * produced by the corresponding for-loop: 964 * <pre>{@code 965 * for (long index=seed; hasNext.test(index); index = next.applyAsLong(index)) { 966 * ... 967 * } 968 * }</pre> 969 * 970 * <p>The resulting sequence may be empty if the {@code hasNext} predicate 971 * does not hold on the seed value. Otherwise the first element will be the 972 * supplied {@code seed} value, the next element (if present) will be the 973 * result of applying the {@code next} function to the {@code seed} value, 974 * and so on iteratively until the {@code hasNext} predicate indicates that 975 * the stream should terminate. 976 * 977 * <p>The action of applying the {@code hasNext} predicate to an element 978 * <a href="../concurrent/package-summary.html#MemoryVisibility"><i>happens-before</i></a> 979 * the action of applying the {@code next} function to that element. The 980 * action of applying the {@code next} function for one element 981 * <i>happens-before</i> the action of applying the {@code hasNext} 982 * predicate for subsequent elements. For any given element an action may 983 * be performed in whatever thread the library chooses. 984 * 985 * @param seed the initial element 986 * @param hasNext a predicate to apply to elements to determine when the 987 * stream must terminate. 988 * @param next a function to be applied to the previous element to produce 989 * a new element 990 * @return a new sequential {@code LongStream} 991 * @since 9 992 */ iterate(long seed, LongPredicate hasNext, LongUnaryOperator next)993 public static LongStream iterate(long seed, LongPredicate hasNext, LongUnaryOperator next) { 994 Objects.requireNonNull(next); 995 Objects.requireNonNull(hasNext); 996 Spliterator.OfLong spliterator = new Spliterators.AbstractLongSpliterator(Long.MAX_VALUE, 997 Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL) { 998 long prev; 999 boolean started, finished; 1000 1001 @Override 1002 public boolean tryAdvance(LongConsumer action) { 1003 Objects.requireNonNull(action); 1004 if (finished) 1005 return false; 1006 long t; 1007 if (started) 1008 t = next.applyAsLong(prev); 1009 else { 1010 t = seed; 1011 started = true; 1012 } 1013 if (!hasNext.test(t)) { 1014 finished = true; 1015 return false; 1016 } 1017 action.accept(prev = t); 1018 return true; 1019 } 1020 1021 @Override 1022 public void forEachRemaining(LongConsumer action) { 1023 Objects.requireNonNull(action); 1024 if (finished) 1025 return; 1026 finished = true; 1027 long t = started ? next.applyAsLong(prev) : seed; 1028 while (hasNext.test(t)) { 1029 action.accept(t); 1030 t = next.applyAsLong(t); 1031 } 1032 } 1033 }; 1034 return StreamSupport.longStream(spliterator, false); 1035 } 1036 1037 /** 1038 * Returns an infinite sequential unordered stream where each element is 1039 * generated by the provided {@code LongSupplier}. This is suitable for 1040 * generating constant streams, streams of random elements, etc. 1041 * 1042 * @param s the {@code LongSupplier} for generated elements 1043 * @return a new infinite sequential unordered {@code LongStream} 1044 */ generate(LongSupplier s)1045 public static LongStream generate(LongSupplier s) { 1046 Objects.requireNonNull(s); 1047 return StreamSupport.longStream( 1048 new StreamSpliterators.InfiniteSupplyingSpliterator.OfLong(Long.MAX_VALUE, s), false); 1049 } 1050 1051 /** 1052 * Returns a sequential ordered {@code LongStream} from {@code startInclusive} 1053 * (inclusive) to {@code endExclusive} (exclusive) by an incremental step of 1054 * {@code 1}. 1055 * 1056 * @apiNote 1057 * <p>An equivalent sequence of increasing values can be produced 1058 * sequentially using a {@code for} loop as follows: 1059 * <pre>{@code 1060 * for (long i = startInclusive; i < endExclusive ; i++) { ... } 1061 * }</pre> 1062 * 1063 * @param startInclusive the (inclusive) initial value 1064 * @param endExclusive the exclusive upper bound 1065 * @return a sequential {@code LongStream} for the range of {@code long} 1066 * elements 1067 */ range(long startInclusive, final long endExclusive)1068 public static LongStream range(long startInclusive, final long endExclusive) { 1069 if (startInclusive >= endExclusive) { 1070 return empty(); 1071 } else if (endExclusive - startInclusive < 0) { 1072 // Size of range > Long.MAX_VALUE 1073 // Split the range in two and concatenate 1074 // Note: if the range is [Long.MIN_VALUE, Long.MAX_VALUE) then 1075 // the lower range, [Long.MIN_VALUE, 0) will be further split in two 1076 long m = startInclusive + Long.divideUnsigned(endExclusive - startInclusive, 2) + 1; 1077 return concat(range(startInclusive, m), range(m, endExclusive)); 1078 } else { 1079 return StreamSupport.longStream( 1080 new Streams.RangeLongSpliterator(startInclusive, endExclusive, false), false); 1081 } 1082 } 1083 1084 /** 1085 * Returns a sequential ordered {@code LongStream} from {@code startInclusive} 1086 * (inclusive) to {@code endInclusive} (inclusive) by an incremental step of 1087 * {@code 1}. 1088 * 1089 * @apiNote 1090 * <p>An equivalent sequence of increasing values can be produced 1091 * sequentially using a {@code for} loop as follows: 1092 * <pre>{@code 1093 * for (long i = startInclusive; i <= endInclusive ; i++) { ... } 1094 * }</pre> 1095 * 1096 * @param startInclusive the (inclusive) initial value 1097 * @param endInclusive the inclusive upper bound 1098 * @return a sequential {@code LongStream} for the range of {@code long} 1099 * elements 1100 */ rangeClosed(long startInclusive, final long endInclusive)1101 public static LongStream rangeClosed(long startInclusive, final long endInclusive) { 1102 if (startInclusive > endInclusive) { 1103 return empty(); 1104 } else if (endInclusive - startInclusive + 1 <= 0) { 1105 // Size of range > Long.MAX_VALUE 1106 // Split the range in two and concatenate 1107 // Note: if the range is [Long.MIN_VALUE, Long.MAX_VALUE] then 1108 // the lower range, [Long.MIN_VALUE, 0), and upper range, 1109 // [0, Long.MAX_VALUE], will both be further split in two 1110 long m = startInclusive + Long.divideUnsigned(endInclusive - startInclusive, 2) + 1; 1111 return concat(range(startInclusive, m), rangeClosed(m, endInclusive)); 1112 } else { 1113 return StreamSupport.longStream( 1114 new Streams.RangeLongSpliterator(startInclusive, endInclusive, true), false); 1115 } 1116 } 1117 1118 /** 1119 * Creates a lazily concatenated stream whose elements are all the 1120 * elements of the first stream followed by all the elements of the 1121 * second stream. The resulting stream is ordered if both 1122 * of the input streams are ordered, and parallel if either of the input 1123 * streams is parallel. When the resulting stream is closed, the close 1124 * handlers for both input streams are invoked. 1125 * 1126 * <p>This method operates on the two input streams and binds each stream 1127 * to its source. As a result subsequent modifications to an input stream 1128 * source may not be reflected in the concatenated stream result. 1129 * 1130 * @implNote 1131 * Use caution when constructing streams from repeated concatenation. 1132 * Accessing an element of a deeply concatenated stream can result in deep 1133 * call chains, or even {@code StackOverflowError}. 1134 * 1135 * @apiNote 1136 * To preserve optimization opportunities this method binds each stream to 1137 * its source and accepts only two streams as parameters. For example, the 1138 * exact size of the concatenated stream source can be computed if the exact 1139 * size of each input stream source is known. 1140 * To concatenate more streams without binding, or without nested calls to 1141 * this method, try creating a stream of streams and flat-mapping with the 1142 * identity function, for example: 1143 * <pre>{@code 1144 * LongStream concat = Stream.of(s1, s2, s3, s4).flatMapToLong(s -> s); 1145 * }</pre> 1146 * 1147 * @param a the first stream 1148 * @param b the second stream 1149 * @return the concatenation of the two input streams 1150 */ concat(LongStream a, LongStream b)1151 public static LongStream concat(LongStream a, LongStream b) { 1152 Objects.requireNonNull(a); 1153 Objects.requireNonNull(b); 1154 1155 Spliterator.OfLong split = new Streams.ConcatSpliterator.OfLong( 1156 a.spliterator(), b.spliterator()); 1157 LongStream stream = StreamSupport.longStream(split, a.isParallel() || b.isParallel()); 1158 return stream.onClose(Streams.composedClose(a, b)); 1159 } 1160 1161 /** 1162 * A mutable builder for a {@code LongStream}. 1163 * 1164 * <p>A stream builder has a lifecycle, which starts in a building 1165 * phase, during which elements can be added, and then transitions to a built 1166 * phase, after which elements may not be added. The built phase begins 1167 * begins when the {@link #build()} method is called, which creates an 1168 * ordered stream whose elements are the elements that were added to the 1169 * stream builder, in the order they were added. 1170 * 1171 * @see LongStream#builder() 1172 * @since 1.8 1173 */ 1174 public interface Builder extends LongConsumer { 1175 1176 /** 1177 * Adds an element to the stream being built. 1178 * 1179 * @throws IllegalStateException if the builder has already transitioned 1180 * to the built state 1181 */ 1182 @Override accept(long t)1183 void accept(long t); 1184 1185 /** 1186 * Adds an element to the stream being built. 1187 * 1188 * @implSpec 1189 * The default implementation behaves as if: 1190 * <pre>{@code 1191 * accept(t) 1192 * return this; 1193 * }</pre> 1194 * 1195 * @param t the element to add 1196 * @return {@code this} builder 1197 * @throws IllegalStateException if the builder has already transitioned 1198 * to the built state 1199 */ add(long t)1200 default Builder add(long t) { 1201 accept(t); 1202 return this; 1203 } 1204 1205 /** 1206 * Builds the stream, transitioning this builder to the built state. 1207 * An {@code IllegalStateException} is thrown if there are further 1208 * attempts to operate on the builder after it has entered the built 1209 * state. 1210 * 1211 * @return the built stream 1212 * @throws IllegalStateException if the builder has already transitioned 1213 * to the built state 1214 */ build()1215 LongStream build(); 1216 } 1217 1218 /** 1219 * Represents an operation that accepts a {@code long}-valued argument 1220 * and a LongConsumer, and returns no result. This functional interface is 1221 * used by {@link LongStream#mapMulti(LongStream.LongMapMultiConsumer) LongStream.mapMulti} 1222 * to replace a long value with zero or more long values. 1223 * 1224 * <p>This is a <a href="../function/package-summary.html">functional interface</a> 1225 * whose functional method is {@link #accept(long, LongConsumer)}. 1226 * 1227 * @see LongStream#mapMulti(LongStream.LongMapMultiConsumer) 1228 * 1229 * @since 16 1230 */ 1231 @FunctionalInterface 1232 interface LongMapMultiConsumer { 1233 1234 /** 1235 * Replaces the given {@code value} with zero or more values by feeding the mapped 1236 * values to the {@code lc} consumer. 1237 * 1238 * @param value the long value coming from upstream 1239 * @param lc a {@code LongConsumer} accepting the mapped values 1240 */ accept(long value, LongConsumer lc)1241 void accept(long value, LongConsumer lc); 1242 } 1243 } 1244