/*
* Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.util;
import java.util.function.IntFunction;
import java.util.function.IntToDoubleFunction;
import java.util.function.IntToLongFunction;
import java.util.function.IntUnaryOperator;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
/**
* This class contains various methods for manipulating arrays (such as
* sorting and searching). This class also contains a static factory
* that allows arrays to be viewed as lists.
*
* <p>The methods in this class all throw a {@code NullPointerException},
* if the specified array reference is null, except where noted.
*
* <p>The documentation for the methods contained in this class includes
* briefs description of the <i>implementations</i>. Such descriptions should
* be regarded as <i>implementation notes</i>, rather than parts of the
* <i>specification</i>. Implementors should feel free to substitute other
* algorithms, so long as the specification itself is adhered to. (For
* example, the algorithm used by {@code sort(Object[])} does not have to be
* a MergeSort, but it does have to be <i>stable</i>.)
*
* <p>This class is a member of the
* <a href="{@docRoot}/../technotes/guides/collections/index.html">
* Java Collections Framework</a>.
*
* @author Josh Bloch
* @author Neal Gafter
* @author John Rose
* @since 1.2
*/
// for desugar: partial copy of new methods in java.util.Arrays used in stream package
public class DesugarArrays {
// Suppresses default constructor, ensuring non-instantiability.
private DesugarArrays() {}
// For desugar: included in Arrays8 so we can call it from Objects
static boolean deepEquals0(Object e1, Object e2) {
assert e1 != null;
boolean eq;
if (e1 instanceof Object[] && e2 instanceof Object[])
eq = Arrays.deepEquals ((Object[]) e1, (Object[]) e2);
else if (e1 instanceof byte[] && e2 instanceof byte[])
eq = Arrays.equals((byte[]) e1, (byte[]) e2);
else if (e1 instanceof short[] && e2 instanceof short[])
eq = Arrays.equals((short[]) e1, (short[]) e2);
else if (e1 instanceof int[] && e2 instanceof int[])
eq = Arrays.equals((int[]) e1, (int[]) e2);
else if (e1 instanceof long[] && e2 instanceof long[])
eq = Arrays.equals((long[]) e1, (long[]) e2);
else if (e1 instanceof char[] && e2 instanceof char[])
eq = Arrays.equals((char[]) e1, (char[]) e2);
else if (e1 instanceof float[] && e2 instanceof float[])
eq = Arrays.equals((float[]) e1, (float[]) e2);
else if (e1 instanceof double[] && e2 instanceof double[])
eq = Arrays.equals((double[]) e1, (double[]) e2);
else if (e1 instanceof boolean[] && e2 instanceof boolean[])
eq = Arrays.equals((boolean[]) e1, (boolean[]) e2);
else
eq = e1.equals(e2);
return eq;
}
/**
* Set all elements of the specified array, using the provided
* generator function to compute each element.
*
* <p>If the generator function throws an exception, it is relayed to
* the caller and the array is left in an indeterminate state.
*
* @param <T> type of elements of the array
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static <T> void setAll(T[] array, IntFunction<? extends T> generator) {
Objects.requireNonNull(generator);
for (int i = 0; i < array.length; i++)
array[i] = generator.apply(i);
}
/**
* Set all elements of the specified array, in parallel, using the
* provided generator function to compute each element.
*
* <p>If the generator function throws an exception, an unchecked exception
* is thrown from {@code parallelSetAll} and the array is left in an
* indeterminate state.
*
* @param <T> type of elements of the array
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static <T> void parallelSetAll(T[] array, IntFunction<? extends T> generator) {
Objects.requireNonNull(generator);
IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.apply(i); });
}
/**
* Set all elements of the specified array, using the provided
* generator function to compute each element.
*
* <p>If the generator function throws an exception, it is relayed to
* the caller and the array is left in an indeterminate state.
*
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static void setAll(int[] array, IntUnaryOperator generator) {
Objects.requireNonNull(generator);
for (int i = 0; i < array.length; i++)
array[i] = generator.applyAsInt(i);
}
/**
* Set all elements of the specified array, in parallel, using the
* provided generator function to compute each element.
*
* <p>If the generator function throws an exception, an unchecked exception
* is thrown from {@code parallelSetAll} and the array is left in an
* indeterminate state.
*
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static void parallelSetAll(int[] array, IntUnaryOperator generator) {
Objects.requireNonNull(generator);
IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.applyAsInt(i); });
}
/**
* Set all elements of the specified array, using the provided
* generator function to compute each element.
*
* <p>If the generator function throws an exception, it is relayed to
* the caller and the array is left in an indeterminate state.
*
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static void setAll(long[] array, IntToLongFunction generator) {
Objects.requireNonNull(generator);
for (int i = 0; i < array.length; i++)
array[i] = generator.applyAsLong(i);
}
/**
* Set all elements of the specified array, in parallel, using the
* provided generator function to compute each element.
*
* <p>If the generator function throws an exception, an unchecked exception
* is thrown from {@code parallelSetAll} and the array is left in an
* indeterminate state.
*
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static void parallelSetAll(long[] array, IntToLongFunction generator) {
Objects.requireNonNull(generator);
IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.applyAsLong(i); });
}
/**
* Set all elements of the specified array, using the provided
* generator function to compute each element.
*
* <p>If the generator function throws an exception, it is relayed to
* the caller and the array is left in an indeterminate state.
*
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static void setAll(double[] array, IntToDoubleFunction generator) {
Objects.requireNonNull(generator);
for (int i = 0; i < array.length; i++)
array[i] = generator.applyAsDouble(i);
}
/**
* Set all elements of the specified array, in parallel, using the
* provided generator function to compute each element.
*
* <p>If the generator function throws an exception, an unchecked exception
* is thrown from {@code parallelSetAll} and the array is left in an
* indeterminate state.
*
* @param array array to be initialized
* @param generator a function accepting an index and producing the desired
* value for that position
* @throws NullPointerException if the generator is null
* @since 1.8
*/
public static void parallelSetAll(double[] array, IntToDoubleFunction generator) {
Objects.requireNonNull(generator);
IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.applyAsDouble(i); });
}
/**
* Returns a {@link Spliterator} covering all of the specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param <T> type of elements
* @param array the array, assumed to be unmodified during use
* @return a spliterator for the array elements
* @since 1.8
*/
public static <T> Spliterator<T> spliterator(T[] array) {
return Spliterators.spliterator(array,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator} covering the specified range of the
* specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param <T> type of elements
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a spliterator for the array elements
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static <T> Spliterator<T> spliterator(T[] array, int startInclusive, int endExclusive) {
return Spliterators.spliterator(array, startInclusive, endExclusive,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator.OfInt} covering all of the specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param array the array, assumed to be unmodified during use
* @return a spliterator for the array elements
* @since 1.8
*/
public static Spliterator.OfInt spliterator(int[] array) {
return Spliterators.spliterator(array,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator.OfInt} covering the specified range of the
* specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a spliterator for the array elements
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static Spliterator.OfInt spliterator(int[] array, int startInclusive, int endExclusive) {
return Spliterators.spliterator(array, startInclusive, endExclusive,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator.OfLong} covering all of the specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param array the array, assumed to be unmodified during use
* @return the spliterator for the array elements
* @since 1.8
*/
public static Spliterator.OfLong spliterator(long[] array) {
return Spliterators.spliterator(array,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator.OfLong} covering the specified range of the
* specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a spliterator for the array elements
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static Spliterator.OfLong spliterator(long[] array, int startInclusive, int endExclusive) {
return Spliterators.spliterator(array, startInclusive, endExclusive,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator.OfDouble} covering all of the specified
* array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param array the array, assumed to be unmodified during use
* @return a spliterator for the array elements
* @since 1.8
*/
public static Spliterator.OfDouble spliterator(double[] array) {
return Spliterators.spliterator(array,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a {@link Spliterator.OfDouble} covering the specified range of
* the specified array.
*
* <p>The spliterator reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
* {@link Spliterator#IMMUTABLE}.
*
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a spliterator for the array elements
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static Spliterator.OfDouble spliterator(double[] array, int startInclusive, int endExclusive) {
return Spliterators.spliterator(array, startInclusive, endExclusive,
Spliterator.ORDERED | Spliterator.IMMUTABLE);
}
/**
* Returns a sequential {@link Stream} with the specified array as its
* source.
*
* @param <T> The type of the array elements
* @param array The array, assumed to be unmodified during use
* @return a {@code Stream} for the array
* @since 1.8
*/
public static <T> Stream<T> stream(T[] array) {
return stream(array, 0, array.length);
}
/**
* Returns a sequential {@link Stream} with the specified range of the
* specified array as its source.
*
* @param <T> the type of the array elements
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a {@code Stream} for the array range
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static <T> Stream<T> stream(T[] array, int startInclusive, int endExclusive) {
return StreamSupport.stream(spliterator(array, startInclusive, endExclusive), false);
}
/**
* Returns a sequential {@link IntStream} with the specified array as its
* source.
*
* @param array the array, assumed to be unmodified during use
* @return an {@code IntStream} for the array
* @since 1.8
*/
public static IntStream stream(int[] array) {
return stream(array, 0, array.length);
}
/**
* Returns a sequential {@link IntStream} with the specified range of the
* specified array as its source.
*
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return an {@code IntStream} for the array range
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static IntStream stream(int[] array, int startInclusive, int endExclusive) {
return StreamSupport.intStream(spliterator(array, startInclusive, endExclusive), false);
}
/**
* Returns a sequential {@link LongStream} with the specified array as its
* source.
*
* @param array the array, assumed to be unmodified during use
* @return a {@code LongStream} for the array
* @since 1.8
*/
public static LongStream stream(long[] array) {
return stream(array, 0, array.length);
}
/**
* Returns a sequential {@link LongStream} with the specified range of the
* specified array as its source.
*
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a {@code LongStream} for the array range
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static LongStream stream(long[] array, int startInclusive, int endExclusive) {
return StreamSupport.longStream(spliterator(array, startInclusive, endExclusive), false);
}
/**
* Returns a sequential {@link DoubleStream} with the specified array as its
* source.
*
* @param array the array, assumed to be unmodified during use
* @return a {@code DoubleStream} for the array
* @since 1.8
*/
public static DoubleStream stream(double[] array) {
return stream(array, 0, array.length);
}
/**
* Returns a sequential {@link DoubleStream} with the specified range of the
* specified array as its source.
*
* @param array the array, assumed to be unmodified during use
* @param startInclusive the first index to cover, inclusive
* @param endExclusive index immediately past the last index to cover
* @return a {@code DoubleStream} for the array range
* @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
* negative, {@code endExclusive} is less than
* {@code startInclusive}, or {@code endExclusive} is greater than
* the array size
* @since 1.8
*/
public static DoubleStream stream(double[] array, int startInclusive, int endExclusive) {
return StreamSupport.doubleStream(spliterator(array, startInclusive, endExclusive), false);
}
}
