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/*
 * Copyright (C) 2016, 2017, 2018, 2019 HaiYang Li
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.landawn.abacus.util.stream;

import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.PrimitiveIterator;
import java.util.Queue;
import java.util.Random;
import java.util.concurrent.TimeUnit;

import com.landawn.abacus.util.ContinuableFuture;
import com.landawn.abacus.util.Fn.Fnn;
import com.landawn.abacus.util.IOUtil;
import com.landawn.abacus.util.IndexedLong;
import com.landawn.abacus.util.LongIterator;
import com.landawn.abacus.util.LongList;
import com.landawn.abacus.util.LongMatrix;
import com.landawn.abacus.util.LongSummaryStatistics;
import com.landawn.abacus.util.MutableInt;
import com.landawn.abacus.util.N;
import com.landawn.abacus.util.Nth;
import com.landawn.abacus.util.Pair;
import com.landawn.abacus.util.Percentage;
import com.landawn.abacus.util.Try;
import com.landawn.abacus.util.u.Holder;
import com.landawn.abacus.util.u.Optional;
import com.landawn.abacus.util.u.OptionalDouble;
import com.landawn.abacus.util.u.OptionalLong;
import com.landawn.abacus.util.function.BiConsumer;
import com.landawn.abacus.util.function.BinaryOperator;
import com.landawn.abacus.util.function.BooleanSupplier;
import com.landawn.abacus.util.function.Function;
import com.landawn.abacus.util.function.LongBiFunction;
import com.landawn.abacus.util.function.LongBiPredicate;
import com.landawn.abacus.util.function.LongBinaryOperator;
import com.landawn.abacus.util.function.LongConsumer;
import com.landawn.abacus.util.function.LongFunction;
import com.landawn.abacus.util.function.LongNFunction;
import com.landawn.abacus.util.function.LongPredicate;
import com.landawn.abacus.util.function.LongSupplier;
import com.landawn.abacus.util.function.LongTernaryOperator;
import com.landawn.abacus.util.function.LongToDoubleFunction;
import com.landawn.abacus.util.function.LongToFloatFunction;
import com.landawn.abacus.util.function.LongToIntFunction;
import com.landawn.abacus.util.function.LongUnaryOperator;
import com.landawn.abacus.util.function.ObjLongConsumer;
import com.landawn.abacus.util.function.Supplier;
import com.landawn.abacus.util.function.ToLongFunction;

/** 
 * The Stream will be automatically closed after execution(A terminal method is executed/triggered).
 * 
 * @see Stream 
 */
public abstract class LongStream extends StreamBase {

    static final Random RAND = new SecureRandom();

    LongStream(final boolean sorted, final Collection closeHandlers) {
        super(sorted, null, closeHandlers);
    }

    public abstract LongStream map(LongUnaryOperator mapper);

    public abstract IntStream mapToInt(LongToIntFunction mapper);

    public abstract FloatStream mapToFloat(LongToFloatFunction mapper);

    public abstract DoubleStream mapToDouble(LongToDoubleFunction mapper);

    public abstract  Stream mapToObj(LongFunction mapper);

    public abstract LongStream flatMap(LongFunction mapper);

    public abstract LongStream flattMap(LongFunction mapper);

    public abstract IntStream flatMapToInt(LongFunction mapper);

    public abstract FloatStream flatMapToFloat(LongFunction mapper);

    public abstract DoubleStream flatMapToDouble(LongFunction mapper);

    public abstract  Stream flatMapToObj(LongFunction> mapper);

    public abstract  Stream flattMapToObj(LongFunction> mapper);

    public abstract  Stream flatMappToObj(LongFunction mapper);

    /**
     * Note: copied from StreamEx: https://github.com/amaembo/streamex
     * 
     * 
* * Returns a stream consisting of results of applying the given function to * the ranges created from the source elements. * This is a quasi-intermediate * partial reduction operation. * * @param sameRange a non-interfering, stateless predicate to apply to * the leftmost and next elements which returns true for elements * which belong to the same range. * @param mapper a non-interfering, stateless function to apply to the * range borders and produce the resulting element. If value was * not merged to the interval, then mapper will receive the same * value twice, otherwise it will receive the leftmost and the * rightmost values which were merged to the range. * @return the new stream * @see #collapse(LongBiPredicate, LongBinaryOperator) * @see Stream#rangeMap(BiPredicate, BiFunction) */ @SequentialOnly public abstract LongStream rangeMap(final LongBiPredicate sameRange, final LongBinaryOperator mapper); /** * Note: copied from StreamEx: https://github.com/amaembo/streamex * *
* * Returns a stream consisting of results of applying the given function to * the ranges created from the source elements. * This is a quasi-intermediate * partial reduction operation. * * @param sameRange a non-interfering, stateless predicate to apply to * the leftmost and next elements which returns true for elements * which belong to the same range. * @param mapper a non-interfering, stateless function to apply to the * range borders and produce the resulting element. If value was * not merged to the interval, then mapper will receive the same * value twice, otherwise it will receive the leftmost and the * rightmost values which were merged to the range. * @return the new stream * @see Stream#rangeMap(BiPredicate, BiFunction) */ @SequentialOnly public abstract Stream rangeMapp(final LongBiPredicate sameRange, final LongBiFunction mapper); /** * Merge series of adjacent elements which satisfy the given predicate using * the merger function and return a new stream. * *
* This method only run sequentially, even in parallel stream. * * @param collapsible * @return */ @SequentialOnly public abstract Stream collapse(final LongBiPredicate collapsible); /** * Merge series of adjacent elements which satisfy the given predicate using * the merger function and return a new stream. * *
* This method only run sequentially, even in parallel stream. * * @param collapsible * @param mergeFunction * @return */ @SequentialOnly public abstract LongStream collapse(final LongBiPredicate collapsible, final LongBinaryOperator mergeFunction); /** * Returns a {@code Stream} produced by iterative application of a accumulation function * to an initial element {@code init} and next element of the current stream. * Produces a {@code Stream} consisting of {@code init}, {@code acc(init, value1)}, * {@code acc(acc(init, value1), value2)}, etc. * *

This is an intermediate operation. * *

Example: *

     * accumulator: (a, b) -> a + b
     * stream: [1, 2, 3, 4, 5]
     * result: [1, 3, 6, 10, 15]
     * 
* *
* This method only run sequentially, even in parallel stream. * * @param accumulator the accumulation function * @return the new stream which has the extract same size as this stream. */ @SequentialOnly public abstract LongStream scan(final LongBinaryOperator accumulator); /** * Returns a {@code Stream} produced by iterative application of a accumulation function * to an initial element {@code init} and next element of the current stream. * Produces a {@code Stream} consisting of {@code init}, {@code acc(init, value1)}, * {@code acc(acc(init, value1), value2)}, etc. * *

This is an intermediate operation. * *

Example: *

     * init:10
     * accumulator: (a, b) -> a + b
     * stream: [1, 2, 3, 4, 5]
     * result: [11, 13, 16, 20, 25]
     * 
* *
* This method only run sequentially, even in parallel stream. * * @param init the initial value. it's only used once by accumulator to calculate the fist element in the returned stream. * It will be ignored if this stream is empty and won't be the first element of the returned stream. * * @param accumulator the accumulation function * @return the new stream which has the extract same size as this stream. */ @SequentialOnly public abstract LongStream scan(final long init, final LongBinaryOperator accumulator); /** * * @param init * @param accumulator * @param initIncluded * @return */ @SequentialOnly public abstract LongStream scan(final long init, final LongBinaryOperator accumulator, final boolean initIncluded); /** *
* This method only run sequentially, even in parallel stream. * * @param n * @return */ @SequentialOnly public abstract LongStream top(int n); /** *
* This method only run sequentially, even in parallel stream. * * @param n * @return */ @SequentialOnly public abstract LongStream top(final int n, Comparator comparator); public abstract LongList toLongList(); /** * * @param keyMapper * @param valueMapper * @return * @see Collectors#toMap(Function, Function) */ public abstract Map toMap(LongFunction keyMapper, LongFunction valueMapper); /** * * @param keyMapper * @param valueMapper * @param mapFactory * @return * @see Collectors#toMap(Function, Function, Supplier) */ public abstract > M toMap(LongFunction keyMapper, LongFunction valueMapper, Supplier mapFactory); /** * * @param keyMapper * @param valueMapper * @param mergeFunction * @return * @see Collectors#toMap(Function, Function, BinaryOperator) */ public abstract Map toMap(LongFunction keyMapper, LongFunction valueMapper, BinaryOperator mergeFunction); /** * * @param keyMapper * @param valueMapper * @param mergeFunction * @param mapFactory * @return * @see Collectors#toMap(Function, Function, BinaryOperator, Supplier) */ public abstract > M toMap(LongFunction keyMapper, LongFunction valueMapper, BinaryOperator mergeFunction, Supplier mapFactory); /** * * @param keyMapper * @param downstream * @return * @see Collectors#groupingBy(Function, Collector) */ public abstract Map toMap(final LongFunction keyMapper, final Collector downstream); /** * * @param keyMapper * @param downstream * @param mapFactory * @return * @see Collectors#groupingBy(Function, Collector, Supplier) */ public abstract > M toMap(final LongFunction keyMapper, final Collector downstream, final Supplier mapFactory); public abstract LongMatrix toMatrix(); public abstract long reduce(long identity, LongBinaryOperator op); public abstract OptionalLong reduce(LongBinaryOperator op); public abstract R collect(Supplier supplier, ObjLongConsumer accumulator, BiConsumer combiner); /** * * @param supplier * @param accumulator * @return */ public abstract R collect(Supplier supplier, ObjLongConsumer accumulator); public abstract void forEach(final Try.LongConsumer action) throws E; public abstract boolean anyMatch(final Try.LongPredicate predicate) throws E; public abstract boolean allMatch(final Try.LongPredicate predicate) throws E; public abstract boolean noneMatch(final Try.LongPredicate predicate) throws E; public abstract OptionalLong findFirst(final Try.LongPredicate predicate) throws E; public abstract OptionalLong findLast(final Try.LongPredicate predicate) throws E; public abstract OptionalLong findFirstOrLast(Try.LongPredicate predicateForFirst, Try.LongPredicate predicateForLast) throws E, E2; public abstract OptionalLong findAny(final Try.LongPredicate predicate) throws E; public abstract OptionalLong min(); public abstract OptionalLong max(); /** * * @param k * @return OptionalByte.empty() if there is no element or count less than k, otherwise the kth largest element. */ public abstract OptionalLong kthLargest(int k); public abstract long sum(); public abstract OptionalDouble average(); public abstract LongSummaryStatistics summarize(); public abstract Pair>> summarizeAndPercentiles(); /** * * @param b * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public abstract LongStream merge(final LongStream b, final LongBiFunction nextSelector); public abstract LongStream zipWith(LongStream b, LongBinaryOperator zipFunction); public abstract LongStream zipWith(LongStream b, LongStream c, LongTernaryOperator zipFunction); public abstract LongStream zipWith(LongStream b, long valueForNoneA, long valueForNoneB, LongBinaryOperator zipFunction); public abstract LongStream zipWith(LongStream b, LongStream c, long valueForNoneA, long valueForNoneB, long valueForNoneC, LongTernaryOperator zipFunction); public abstract FloatStream asFloatStream(); public abstract DoubleStream asDoubleStream(); public abstract java.util.stream.LongStream toJdkStream(); public abstract Stream boxed(); /** * Remember to close this Stream after the iteration is done, if required. * * @return */ @SequentialOnly @Override public LongIterator iterator() { return iteratorEx(); } abstract LongIteratorEx iteratorEx(); @Override public R __(Function transfer) { return transfer.apply(this); } public static LongStream empty() { return new ArrayLongStream(N.EMPTY_LONG_ARRAY, true, null); } @SafeVarargs public static LongStream of(final long... a) { return N.isNullOrEmpty(a) ? empty() : new ArrayLongStream(a); } public static LongStream of(final long[] a, final int startIndex, final int endIndex) { return N.isNullOrEmpty(a) && (startIndex == 0 && endIndex == 0) ? empty() : new ArrayLongStream(a, startIndex, endIndex); } public static LongStream of(final Long[] a) { return Stream.of(a).mapToLong(Fnn.unboxL()); } public static LongStream of(final Long[] a, final int startIndex, final int endIndex) { return Stream.of(a, startIndex, endIndex).mapToLong(Fnn.unboxL()); } public static LongStream of(final Collection c) { return Stream.of(c).mapToLong(Fnn.unboxL()); } public static LongStream of(final LongIterator iterator) { return iterator == null ? empty() : new IteratorLongStream(iterator); } /** * Lazy evaluation. * @param supplier * @return */ public static LongStream of(final Supplier supplier) { final LongIterator iter = new LongIteratorEx() { private LongIterator iterator = null; @Override public boolean hasNext() { if (iterator == null) { init(); } return iterator.hasNext(); } @Override public long nextLong() { if (iterator == null) { init(); } return iterator.nextLong(); } private void init() { final LongList c = supplier.get(); if (N.isNullOrEmpty(c)) { iterator = LongIterator.empty(); } else { iterator = c.iterator(); } } }; return of(iter); } private static final Function flatMapper = new Function() { @Override public LongStream apply(long[] t) { return LongStream.of(t); } }; private static final Function flatMappper = new Function() { @Override public LongStream apply(long[][] t) { return LongStream.flat(t); } }; public static LongStream of(final java.util.stream.LongStream stream) { return of(new LongIteratorEx() { private PrimitiveIterator.OfLong iter = null; @Override public boolean hasNext() { if (iter == null) { iter = stream.iterator(); } return iter.hasNext(); } @Override public long nextLong() { if (iter == null) { iter = stream.iterator(); } return iter.nextLong(); } @Override public long count() { return iter == null ? stream.count() : super.count(); } @Override public void skip(long n) { if (iter == null) { iter = stream.skip(n).iterator(); } else { super.skip(n); } } @Override public long[] toArray() { return iter == null ? stream.toArray() : super.toArray(); } }).__(s -> stream.isParallel() ? s.parallel() : s.sequential()).onClose(new Runnable() { @Override public void run() { stream.close(); } }); } public static LongStream flat(final long[][] a) { return N.isNullOrEmpty(a) ? empty() : Stream.of(a).flatMapToLong(flatMapper); } public static LongStream flat(final long[][] a, final boolean vertically) { if (N.isNullOrEmpty(a)) { return empty(); } else if (a.length == 1) { return of(a[0]); } else if (vertically == false) { return Stream.of(a).flatMapToLong(flatMapper); } long n = 0; for (long[] e : a) { n += N.len(e); } if (n == 0) { return empty(); } final int rows = N.len(a); final long count = n; final LongIterator iter = new LongIteratorEx() { private int rowNum = 0; private int colNum = 0; private long cnt = 0; @Override public boolean hasNext() { return cnt < count; } @Override public long nextLong() { if (cnt++ >= count) { throw new NoSuchElementException(); } if (rowNum == rows) { rowNum = 0; colNum++; } while (a[rowNum] == null || colNum >= a[rowNum].length) { if (rowNum < rows - 1) { rowNum++; } else { rowNum = 0; colNum++; } } return a[rowNum++][colNum]; } }; return of(iter); } public static LongStream flat(final long[][] a, final long valueForNone, final boolean vertically) { if (N.isNullOrEmpty(a)) { return empty(); } else if (a.length == 1) { return of(a[0]); } long n = 0; int maxLen = 0; for (long[] e : a) { n += N.len(e); maxLen = N.max(maxLen, N.len(e)); } if (n == 0) { return empty(); } final int rows = N.len(a); final int cols = maxLen; final long count = rows * cols; LongIterator iter = null; if (vertically) { iter = new LongIteratorEx() { private int rowNum = 0; private int colNum = 0; private long cnt = 0; @Override public boolean hasNext() { return cnt < count; } @Override public long nextLong() { if (cnt++ >= count) { throw new NoSuchElementException(); } if (rowNum == rows) { rowNum = 0; colNum++; } if (a[rowNum] == null || colNum >= a[rowNum].length) { rowNum++; return valueForNone; } else { return a[rowNum++][colNum]; } } }; } else { iter = new LongIteratorEx() { private int rowNum = 0; private int colNum = 0; private long cnt = 0; @Override public boolean hasNext() { return cnt < count; } @Override public long nextLong() { if (cnt++ >= count) { throw new NoSuchElementException(); } if (colNum >= cols) { colNum = 0; rowNum++; } if (a[rowNum] == null || colNum >= a[rowNum].length) { colNum++; return valueForNone; } else { return a[rowNum][colNum++]; } } }; } return of(iter); } public static LongStream flat(final long[][][] a) { return N.isNullOrEmpty(a) ? empty() : Stream.of(a).flatMapToLong(flatMappper); } public static LongStream range(final long startInclusive, final long endExclusive) { if (startInclusive >= endExclusive) { return empty(); } else if (endExclusive - startInclusive < 0) { final long m = BigInteger.valueOf(endExclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue(); return concat(range(startInclusive, startInclusive + m), range(startInclusive + m, (startInclusive + m) + m), range((startInclusive + m) + m, endExclusive)); } return new IteratorLongStream(new LongIteratorEx() { private long next = startInclusive; private long cnt = endExclusive - startInclusive; @Override public boolean hasNext() { return cnt > 0; } @Override public long nextLong() { if (cnt-- <= 0) { throw new NoSuchElementException(); } return next++; } @Override public void skip(long n) { N.checkArgNotNegative(n, "n"); cnt = n >= cnt ? 0 : cnt - n; next += n; } @Override public long count() { return cnt; } @Override public long[] toArray() { final long[] result = new long[(int) cnt]; for (int i = 0; i < cnt; i++) { result[i] = next++; } cnt = 0; return result; } }); } public static LongStream range(final long startInclusive, final long endExclusive, final long by) { if (by == 0) { throw new IllegalArgumentException("'by' can't be zero"); } if (endExclusive == startInclusive || endExclusive > startInclusive != by > 0) { return empty(); } if ((by > 0 && endExclusive - startInclusive < 0) || (by < 0 && startInclusive - endExclusive < 0)) { long m = BigInteger.valueOf(endExclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue(); if ((by > 0 && by > m) || (by < 0 && by < m)) { return concat(range(startInclusive, startInclusive + by), range(startInclusive + by, endExclusive)); } else { m = m > 0 ? m - m % by : m + m % by; return concat(range(startInclusive, startInclusive + m, by), range(startInclusive + m, (startInclusive + m) + m, by), range((startInclusive + m) + m, endExclusive, by)); } } return new IteratorLongStream(new LongIteratorEx() { private long next = startInclusive; private long cnt = (endExclusive - startInclusive) / by + ((endExclusive - startInclusive) % by == 0 ? 0 : 1); @Override public boolean hasNext() { return cnt > 0; } @Override public long nextLong() { if (cnt-- <= 0) { throw new NoSuchElementException(); } long result = next; next += by; return result; } @Override public void skip(long n) { N.checkArgNotNegative(n, "n"); cnt = n >= cnt ? 0 : cnt - n; next += n * by; } @Override public long count() { return cnt; } @Override public long[] toArray() { final long[] result = new long[(int) cnt]; for (int i = 0; i < cnt; i++, next += by) { result[i] = next; } cnt = 0; return result; } }); } public static LongStream rangeClosed(final long startInclusive, final long endInclusive) { if (startInclusive > endInclusive) { return empty(); } else if (startInclusive == endInclusive) { return of(startInclusive); } else if (endInclusive - startInclusive + 1 <= 0) { final long m = BigInteger.valueOf(endInclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue(); return concat(range(startInclusive, startInclusive + m), range(startInclusive + m, (startInclusive + m) + m), rangeClosed((startInclusive + m) + m, endInclusive)); } return new IteratorLongStream(new LongIteratorEx() { private long next = startInclusive; private long cnt = endInclusive - startInclusive + 1; @Override public boolean hasNext() { return cnt > 0; } @Override public long nextLong() { if (cnt-- <= 0) { throw new NoSuchElementException(); } return next++; } @Override public void skip(long n) { N.checkArgNotNegative(n, "n"); cnt = n >= cnt ? 0 : cnt - n; next += n; } @Override public long count() { return cnt; } @Override public long[] toArray() { final long[] result = new long[(int) cnt]; for (int i = 0; i < cnt; i++) { result[i] = next++; } cnt = 0; return result; } }); } public static LongStream rangeClosed(final long startInclusive, final long endInclusive, final long by) { if (by == 0) { throw new IllegalArgumentException("'by' can't be zero"); } if (endInclusive == startInclusive) { return of(startInclusive); } else if (endInclusive > startInclusive != by > 0) { return empty(); } if ((by > 0 && endInclusive - startInclusive < 0) || (by < 0 && startInclusive - endInclusive < 0) || ((endInclusive - startInclusive) / by + 1 <= 0)) { long m = BigInteger.valueOf(endInclusive).subtract(BigInteger.valueOf(startInclusive)).divide(BigInteger.valueOf(3)).longValue(); if ((by > 0 && by > m) || (by < 0 && by < m)) { return concat(range(startInclusive, startInclusive + by), rangeClosed(startInclusive + by, endInclusive)); } else { m = m > 0 ? m - m % by : m + m % by; return concat(range(startInclusive, startInclusive + m, by), range(startInclusive + m, (startInclusive + m) + m, by), rangeClosed((startInclusive + m) + m, endInclusive, by)); } } return new IteratorLongStream(new LongIteratorEx() { private long next = startInclusive; private long cnt = (endInclusive - startInclusive) / by + 1; @Override public boolean hasNext() { return cnt > 0; } @Override public long nextLong() { if (cnt-- <= 0) { throw new NoSuchElementException(); } long result = next; next += by; return result; } @Override public void skip(long n) { N.checkArgNotNegative(n, "n"); cnt = n >= cnt ? 0 : cnt - n; next += n * by; } @Override public long count() { return cnt; } @Override public long[] toArray() { final long[] result = new long[(int) cnt]; for (int i = 0; i < cnt; i++, next += by) { result[i] = next; } cnt = 0; return result; } }); } public static LongStream repeat(final long element, final long n) { N.checkArgNotNegative(n, "n"); if (n == 0) { return empty(); } return new IteratorLongStream(new LongIteratorEx() { private long cnt = n; @Override public boolean hasNext() { return cnt > 0; } @Override public long nextLong() { if (cnt-- <= 0) { throw new NoSuchElementException(); } return element; } @Override public void skip(long n) { N.checkArgNotNegative(n, "n"); cnt = n >= cnt ? 0 : cnt - (int) n; } @Override public long count() { return cnt; } @Override public long[] toArray() { final long[] result = new long[(int) cnt]; for (int i = 0; i < cnt; i++) { result[i] = element; } cnt = 0; return result; } }); } public static LongStream random() { return generate(new LongSupplier() { @Override public long getAsLong() { return RAND.nextLong(); } }); } public static LongStream iterate(final BooleanSupplier hasNext, final LongSupplier next) { N.checkArgNotNull(hasNext); N.checkArgNotNull(next); return new IteratorLongStream(new LongIteratorEx() { private boolean hasNextVal = false; @Override public boolean hasNext() { if (hasNextVal == false) { hasNextVal = hasNext.getAsBoolean(); } return hasNextVal; } @Override public long nextLong() { if (hasNextVal == false && hasNext() == false) { throw new NoSuchElementException(); } hasNextVal = false; return next.getAsLong(); } }); } public static LongStream iterate(final long init, final BooleanSupplier hasNext, final LongUnaryOperator f) { N.checkArgNotNull(hasNext); N.checkArgNotNull(f); return new IteratorLongStream(new LongIteratorEx() { private long t = 0; private boolean isFirst = true; private boolean hasNextVal = false; @Override public boolean hasNext() { if (hasNextVal == false) { hasNextVal = hasNext.getAsBoolean(); } return hasNextVal; } @Override public long nextLong() { if (hasNextVal == false && hasNext() == false) { throw new NoSuchElementException(); } hasNextVal = false; if (isFirst) { isFirst = false; t = init; } else { t = f.applyAsLong(t); } return t; } }); } /** * * @param init * @param hasNext test if has next by hasNext.test(init) for first time and hasNext.test(f.apply(previous)) for remaining. * @param f * @return */ public static LongStream iterate(final long init, final LongPredicate hasNext, final LongUnaryOperator f) { N.checkArgNotNull(hasNext); N.checkArgNotNull(f); return new IteratorLongStream(new LongIteratorEx() { private long t = 0; private long cur = 0; private boolean isFirst = true; private boolean hasMore = true; private boolean hasNextVal = false; @Override public boolean hasNext() { if (hasNextVal == false && hasMore) { if (isFirst) { isFirst = false; hasNextVal = hasNext.test(cur = init); } else { hasNextVal = hasNext.test(cur = f.applyAsLong(t)); } if (hasNextVal == false) { hasMore = false; } } return hasNextVal; } @Override public long nextLong() { if (hasNextVal == false && hasNext() == false) { throw new NoSuchElementException(); } t = cur; hasNextVal = false; return t; } }); } public static LongStream iterate(final long init, final LongUnaryOperator f) { N.checkArgNotNull(f); return new IteratorLongStream(new LongIteratorEx() { private long t = 0; private boolean isFirst = true; @Override public boolean hasNext() { return true; } @Override public long nextLong() { if (isFirst) { isFirst = false; t = init; } else { t = f.applyAsLong(t); } return t; } }); } public static LongStream generate(final LongSupplier s) { N.checkArgNotNull(s); return new IteratorLongStream(new LongIteratorEx() { @Override public boolean hasNext() { return true; } @Override public long nextLong() { return s.getAsLong(); } }); } /** * * @param intervalInMillis * @return */ public static LongStream interval(final long intervalInMillis) { return interval(0, intervalInMillis); } /** * Generates the long value by the specified period: [0, 1, 2, 3...] * * @param delayInMillis * @param intervalInMillis * @return */ public static LongStream interval(final long delayInMillis, final long intervalInMillis) { return interval(delayInMillis, intervalInMillis, TimeUnit.MILLISECONDS); } /** * Generates the long value by the specified period: [0, 1, 2, 3...] * * @param delay * @param interval * @param unit * @return */ public static LongStream interval(final long delay, final long interval, final TimeUnit unit) { return of(new LongIteratorEx() { private final long intervalInMillis = unit.toMillis(interval); private long nextTime = System.currentTimeMillis() + unit.toMillis(delay); private long val = 0; @Override public boolean hasNext() { return true; } @Override public long nextLong() { long now = System.currentTimeMillis(); if (now < nextTime) { N.sleep(nextTime - now); } nextTime += intervalInMillis; return val++; } }); } @SafeVarargs public static LongStream concat(final long[]... a) { return N.isNullOrEmpty(a) ? empty() : new IteratorLongStream(new LongIteratorEx() { private final Iterator iter = N.asList(a).iterator(); private LongIterator cur; @Override public boolean hasNext() { while ((cur == null || cur.hasNext() == false) && iter.hasNext()) { cur = LongIteratorEx.of(iter.next()); } return cur != null && cur.hasNext(); } @Override public long nextLong() { if ((cur == null || cur.hasNext() == false) && hasNext() == false) { throw new NoSuchElementException(); } return cur.nextLong(); } }); } @SafeVarargs public static LongStream concat(final LongIterator... a) { return N.isNullOrEmpty(a) ? empty() : new IteratorLongStream(new LongIteratorEx() { private final Iterator iter = N.asList(a).iterator(); private LongIterator cur; @Override public boolean hasNext() { while ((cur == null || cur.hasNext() == false) && iter.hasNext()) { cur = iter.next(); } return cur != null && cur.hasNext(); } @Override public long nextLong() { if ((cur == null || cur.hasNext() == false) && hasNext() == false) { throw new NoSuchElementException(); } return cur.nextLong(); } }); } @SafeVarargs public static LongStream concat(final LongStream... a) { return N.isNullOrEmpty(a) ? empty() : concat(N.asList(a)); } public static LongStream concat(final Collection c) { return N.isNullOrEmpty(c) ? empty() : new IteratorLongStream(new LongIteratorEx() { private final Iterator iterators = c.iterator(); private LongStream cur; private LongIterator iter; @Override public boolean hasNext() { while ((iter == null || iter.hasNext() == false) && iterators.hasNext()) { if (cur != null) { cur.close(); } cur = iterators.next(); iter = cur.iterator(); } return iter != null && iter.hasNext(); } @Override public long nextLong() { if ((iter == null || iter.hasNext() == false) && hasNext() == false) { throw new NoSuchElementException(); } return iter.nextLong(); } }).onClose(newCloseHandler(c)); } /** * Zip together the "a" and "b" arrays until one of them runs out of values. * Each pair of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @return */ public static LongStream zip(final long[] a, final long[] b, final LongBinaryOperator zipFunction) { if (N.isNullOrEmpty(a) || N.isNullOrEmpty(b)) { return empty(); } return new IteratorLongStream(new LongIteratorEx() { private final int len = N.min(N.len(a), N.len(b)); private int cursor = 0; @Override public boolean hasNext() { return cursor < len; } @Override public long nextLong() { if (cursor >= len) { throw new NoSuchElementException(); } return zipFunction.applyAsLong(a[cursor], b[cursor++]); } }); } /** * Zip together the "a", "b" and "c" arrays until one of them runs out of values. * Each triple of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param c * @return */ public static LongStream zip(final long[] a, final long[] b, final long[] c, final LongTernaryOperator zipFunction) { if (N.isNullOrEmpty(a) || N.isNullOrEmpty(b) || N.isNullOrEmpty(c)) { return empty(); } return new IteratorLongStream(new LongIteratorEx() { private final int len = N.min(N.len(a), N.len(b), N.len(c)); private int cursor = 0; @Override public boolean hasNext() { return cursor < len; } @Override public long nextLong() { if (cursor >= len) { throw new NoSuchElementException(); } return zipFunction.applyAsLong(a[cursor], b[cursor], c[cursor++]); } }); } /** * Zip together the "a" and "b" iterators until one of them runs out of values. * Each pair of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @return */ public static LongStream zip(final LongIterator a, final LongIterator b, final LongBinaryOperator zipFunction) { return new IteratorLongStream(new LongIteratorEx() { @Override public boolean hasNext() { return a.hasNext() && b.hasNext(); } @Override public long nextLong() { return zipFunction.applyAsLong(a.nextLong(), b.nextLong()); } }); } /** * Zip together the "a", "b" and "c" iterators until one of them runs out of values. * Each triple of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @return */ public static LongStream zip(final LongIterator a, final LongIterator b, final LongIterator c, final LongTernaryOperator zipFunction) { return new IteratorLongStream(new LongIteratorEx() { @Override public boolean hasNext() { return a.hasNext() && b.hasNext() && c.hasNext(); } @Override public long nextLong() { return zipFunction.applyAsLong(a.nextLong(), b.nextLong(), c.nextLong()); } }); } /** * Zip together the "a" and "b" streams until one of them runs out of values. * Each pair of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @return */ public static LongStream zip(final LongStream a, final LongStream b, final LongBinaryOperator zipFunction) { return zip(a.iteratorEx(), b.iteratorEx(), zipFunction).onClose(newCloseHandler(N.asList(a, b))); } /** * Zip together the "a", "b" and "c" streams until one of them runs out of values. * Each triple of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @return */ public static LongStream zip(final LongStream a, final LongStream b, final LongStream c, final LongTernaryOperator zipFunction) { return zip(a.iteratorEx(), b.iteratorEx(), c.iteratorEx(), zipFunction).onClose(newCloseHandler(N.asList(a, b, c))); } /** * Zip together the iterators until one of them runs out of values. * Each array of values is combined into a single value using the supplied zipFunction function. * * @param c * @param zipFunction * @return */ public static LongStream zip(final Collection c, final LongNFunction zipFunction) { return Stream.zip(c, zipFunction).mapToLong(ToLongFunction.UNBOX); } /** * Zip together the "a" and "b" iterators until all of them runs out of values. * Each pair of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param valueForNoneA value to fill if "a" runs out of values first. * @param valueForNoneB value to fill if "b" runs out of values first. * @param zipFunction * @return */ public static LongStream zip(final long[] a, final long[] b, final long valueForNoneA, final long valueForNoneB, final LongBinaryOperator zipFunction) { if (N.isNullOrEmpty(a) && N.isNullOrEmpty(b)) { return empty(); } return new IteratorLongStream(new LongIteratorEx() { private final int aLen = N.len(a), bLen = N.len(b), len = N.max(aLen, bLen); private int cursor = 0; private long ret = 0; @Override public boolean hasNext() { return cursor < len; } @Override public long nextLong() { if (cursor >= len) { throw new NoSuchElementException(); } ret = zipFunction.applyAsLong(cursor < aLen ? a[cursor] : valueForNoneA, cursor < bLen ? b[cursor] : valueForNoneB); cursor++; return ret; } }); } /** * Zip together the "a", "b" and "c" iterators until all of them runs out of values. * Each triple of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param c * @param valueForNoneA value to fill if "a" runs out of values. * @param valueForNoneB value to fill if "b" runs out of values. * @param valueForNoneC value to fill if "c" runs out of values. * @param zipFunction * @return */ public static LongStream zip(final long[] a, final long[] b, final long[] c, final long valueForNoneA, final long valueForNoneB, final long valueForNoneC, final LongTernaryOperator zipFunction) { if (N.isNullOrEmpty(a) && N.isNullOrEmpty(b) && N.isNullOrEmpty(c)) { return empty(); } return new IteratorLongStream(new LongIteratorEx() { private final int aLen = N.len(a), bLen = N.len(b), cLen = N.len(c), len = N.max(aLen, bLen, cLen); private int cursor = 0; private long ret = 0; @Override public boolean hasNext() { return cursor < len; } @Override public long nextLong() { if (cursor >= len) { throw new NoSuchElementException(); } ret = zipFunction.applyAsLong(cursor < aLen ? a[cursor] : valueForNoneA, cursor < bLen ? b[cursor] : valueForNoneB, cursor < cLen ? c[cursor] : valueForNoneC); cursor++; return ret; } }); } /** * Zip together the "a" and "b" iterators until all of them runs out of values. * Each pair of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param valueForNoneA value to fill if "a" runs out of values first. * @param valueForNoneB value to fill if "b" runs out of values first. * @param zipFunction * @return */ public static LongStream zip(final LongIterator a, final LongIterator b, final long valueForNoneA, final long valueForNoneB, final LongBinaryOperator zipFunction) { return new IteratorLongStream(new LongIteratorEx() { @Override public boolean hasNext() { return a.hasNext() || b.hasNext(); } @Override public long nextLong() { if (a.hasNext()) { return zipFunction.applyAsLong(a.nextLong(), b.hasNext() ? b.nextLong() : valueForNoneB); } else { return zipFunction.applyAsLong(valueForNoneA, b.nextLong()); } } }); } /** * Zip together the "a", "b" and "c" iterators until all of them runs out of values. * Each triple of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param c * @param valueForNoneA value to fill if "a" runs out of values. * @param valueForNoneB value to fill if "b" runs out of values. * @param valueForNoneC value to fill if "c" runs out of values. * @param zipFunction * @return */ public static LongStream zip(final LongIterator a, final LongIterator b, final LongIterator c, final long valueForNoneA, final long valueForNoneB, final long valueForNoneC, final LongTernaryOperator zipFunction) { return new IteratorLongStream(new LongIteratorEx() { @Override public boolean hasNext() { return a.hasNext() || b.hasNext() || c.hasNext(); } @Override public long nextLong() { if (a.hasNext()) { return zipFunction.applyAsLong(a.nextLong(), b.hasNext() ? b.nextLong() : valueForNoneB, c.hasNext() ? c.nextLong() : valueForNoneC); } else if (b.hasNext()) { return zipFunction.applyAsLong(valueForNoneA, b.nextLong(), c.hasNext() ? c.nextLong() : valueForNoneC); } else { return zipFunction.applyAsLong(valueForNoneA, valueForNoneB, c.nextLong()); } } }); } /** * Zip together the "a" and "b" iterators until all of them runs out of values. * Each pair of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param valueForNoneA value to fill if "a" runs out of values first. * @param valueForNoneB value to fill if "b" runs out of values first. * @param zipFunction * @return */ public static LongStream zip(final LongStream a, final LongStream b, final long valueForNoneA, final long valueForNoneB, final LongBinaryOperator zipFunction) { return zip(a.iteratorEx(), b.iteratorEx(), valueForNoneA, valueForNoneB, zipFunction).onClose(newCloseHandler(N.asList(a, b))); } /** * Zip together the "a", "b" and "c" iterators until all of them runs out of values. * Each triple of values is combined into a single value using the supplied zipFunction function. * * @param a * @param b * @param c * @param valueForNoneA value to fill if "a" runs out of values. * @param valueForNoneB value to fill if "b" runs out of values. * @param valueForNoneC value to fill if "c" runs out of values. * @param zipFunction * @return */ public static LongStream zip(final LongStream a, final LongStream b, final LongStream c, final long valueForNoneA, final long valueForNoneB, final long valueForNoneC, final LongTernaryOperator zipFunction) { return zip(a.iteratorEx(), b.iteratorEx(), c.iteratorEx(), valueForNoneA, valueForNoneB, valueForNoneC, zipFunction) .onClose(newCloseHandler(N.asList(a, b, c))); } /** * Zip together the iterators until all of them runs out of values. * Each array of values is combined into a single value using the supplied zipFunction function. * * @param c * @param valuesForNone value to fill for any iterator runs out of values. * @param zipFunction * @return */ public static LongStream zip(final Collection c, final long[] valuesForNone, final LongNFunction zipFunction) { return Stream.zip(c, valuesForNone, zipFunction).mapToLong(ToLongFunction.UNBOX); } /** * * @param a * @param b * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final long[] a, final long[] b, final LongBiFunction nextSelector) { if (N.isNullOrEmpty(a)) { return of(b); } else if (N.isNullOrEmpty(b)) { return of(a); } return new IteratorLongStream(new LongIteratorEx() { private final int lenA = a.length; private final int lenB = b.length; private int cursorA = 0; private int cursorB = 0; @Override public boolean hasNext() { return cursorA < lenA || cursorB < lenB; } @Override public long nextLong() { if (cursorA < lenA) { if (cursorB < lenB) { if (nextSelector.apply(a[cursorA], b[cursorB]) == Nth.FIRST) { return a[cursorA++]; } else { return b[cursorB++]; } } else { return a[cursorA++]; } } else if (cursorB < lenB) { return b[cursorB++]; } else { throw new NoSuchElementException(); } } }); } /** * * @param a * @param b * @param c * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final long[] a, final long[] b, final long[] c, final LongBiFunction nextSelector) { return merge(merge(a, b, nextSelector).iteratorEx(), LongStream.of(c).iteratorEx(), nextSelector); } /** * * @param a * @param b * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final LongIterator a, final LongIterator b, final LongBiFunction nextSelector) { return new IteratorLongStream(new LongIteratorEx() { private long nextA = 0; private long nextB = 0; private boolean hasNextA = false; private boolean hasNextB = false; @Override public boolean hasNext() { return a.hasNext() || b.hasNext() || hasNextA || hasNextB; } @Override public long nextLong() { if (hasNextA) { if (b.hasNext()) { if (nextSelector.apply(nextA, (nextB = b.nextLong())) == Nth.FIRST) { hasNextA = false; hasNextB = true; return nextA; } else { return nextB; } } else { hasNextA = false; return nextA; } } else if (hasNextB) { if (a.hasNext()) { if (nextSelector.apply((nextA = a.nextLong()), nextB) == Nth.FIRST) { return nextA; } else { hasNextA = true; hasNextB = false; return nextB; } } else { hasNextB = false; return nextB; } } else if (a.hasNext()) { if (b.hasNext()) { if (nextSelector.apply((nextA = a.nextLong()), (nextB = b.nextLong())) == Nth.FIRST) { hasNextB = true; return nextA; } else { hasNextA = true; return nextB; } } else { return a.nextLong(); } } else if (b.hasNext()) { return b.nextLong(); } else { throw new NoSuchElementException(); } } }); } /** * * @param a * @param b * @param c * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final LongIterator a, final LongIterator b, final LongIterator c, final LongBiFunction nextSelector) { return merge(merge(a, b, nextSelector).iteratorEx(), c, nextSelector); } /** * * @param a * @param b * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final LongStream a, final LongStream b, final LongBiFunction nextSelector) { return merge(a.iteratorEx(), b.iteratorEx(), nextSelector).onClose(newCloseHandler(N.asList(a, b))); } /** * * @param a * @param b * @param c * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final LongStream a, final LongStream b, final LongStream c, final LongBiFunction nextSelector) { return merge(merge(a, b, nextSelector), c, nextSelector); } /** * * @param c * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream merge(final Collection c, final LongBiFunction nextSelector) { if (N.isNullOrEmpty(c)) { return empty(); } else if (c.size() == 1) { return c.iterator().next(); } else if (c.size() == 2) { final Iterator iter = c.iterator(); return merge(iter.next(), iter.next(), nextSelector); } final Iterator iter = c.iterator(); LongStream result = merge(iter.next(), iter.next(), nextSelector); while (iter.hasNext()) { result = merge(result, iter.next(), nextSelector); } return result; } /** * * @param c * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @return */ public static LongStream parallelMerge(final Collection c, final LongBiFunction nextSelector) { return parallelMerge(c, nextSelector, DEFAULT_MAX_THREAD_NUM); } /** * * @param c * @param nextSelector first parameter is selected if Nth.FIRST is returned, otherwise the second parameter is selected. * @param maxThreadNum * @return */ public static LongStream parallelMerge(final Collection c, final LongBiFunction nextSelector, final int maxThreadNum) { N.checkArgument(maxThreadNum > 0, "'maxThreadNum' must not less than 1"); if (maxThreadNum <= 1) { return merge(c, nextSelector); } else if (N.isNullOrEmpty(c)) { return empty(); } else if (c.size() == 1) { return c.iterator().next(); } else if (c.size() == 2) { final Iterator iter = c.iterator(); return merge(iter.next(), iter.next(), nextSelector); } else if (c.size() == 3) { final Iterator iter = c.iterator(); return merge(iter.next(), iter.next(), iter.next(), nextSelector); } final Queue queue = N.newLinkedList(); for (LongStream e : c) { queue.add(e); } final Holder eHolder = new Holder<>(); final MutableInt cnt = MutableInt.of(c.size()); final List> futureList = new ArrayList<>(c.size() - 1); for (int i = 0, n = N.min(maxThreadNum, c.size() / 2 + 1); i < n; i++) { futureList.add(DEFAULT_ASYNC_EXECUTOR.execute(new Try.Runnable() { @Override public void run() { LongStream a = null; LongStream b = null; LongStream c = null; try { while (eHolder.value() == null) { synchronized (queue) { if (cnt.intValue() > 2 && queue.size() > 1) { a = queue.poll(); b = queue.poll(); cnt.decrement(); } else { break; } } c = LongStream.of(merge(a, b, nextSelector).toArray()); synchronized (queue) { queue.offer(c); } } } catch (Exception e) { setError(eHolder, e); } } })); } try { complete(futureList, eHolder); } finally { if (eHolder.value() != null) { IOUtil.closeAllQuietly(c); } } return merge(queue.poll(), queue.poll(), nextSelector); } public static abstract class LongStreamEx extends LongStream { private LongStreamEx(boolean sorted, Collection closeHandlers) { super(sorted, closeHandlers); // Factory class. } } }