/* * Copyright (C) 2008 The Guava Authors * * 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.google.common.primitives; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.base.Preconditions.checkElementIndex; import static com.google.common.base.Preconditions.checkNotNull; import static com.google.common.base.Preconditions.checkPositionIndexes; import com.google.common.annotations.Beta; import com.google.common.annotations.GwtCompatible; import com.google.common.base.Converter; import java.io.Serializable; import java.util.AbstractList; import java.util.Collection; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.RandomAccess; /** * Static utility methods pertaining to {@code short} primitives, that are not * already found in either {@link Short} or {@link Arrays}. * *
See the Guava User Guide article on * primitive utilities. * * @author Kevin Bourrillion * @since 1.0 */ @GwtCompatible(emulated = true) public final class Shorts { private Shorts() {} /** * The number of bytes required to represent a primitive {@code short} * value. */ public static final int BYTES = Short.SIZE / Byte.SIZE; /** * The largest power of two that can be represented as a {@code short}. * * @since 10.0 */ public static final short MAX_POWER_OF_TWO = 1 << (Short.SIZE - 2); /** * Returns a hash code for {@code value}; equal to the result of invoking * {@code ((Short) value).hashCode()}. * * @param value a primitive {@code short} value * @return a hash code for the value */ public static int hashCode(short value) { return value; } /** * Returns the {@code short} value that is equal to {@code value}, if * possible. * * @param value any value in the range of the {@code short} type * @return the {@code short} value that equals {@code value} * @throws IllegalArgumentException if {@code value} is greater than {@link * Short#MAX_VALUE} or less than {@link Short#MIN_VALUE} */ public static short checkedCast(long value) { short result = (short) value; if (result != value) { // don't use checkArgument here, to avoid boxing throw new IllegalArgumentException("Out of range: " + value); } return result; } /** * Returns the {@code short} nearest in value to {@code value}. * * @param value any {@code long} value * @return the same value cast to {@code short} if it is in the range of the * {@code short} type, {@link Short#MAX_VALUE} if it is too large, * or {@link Short#MIN_VALUE} if it is too small */ public static short saturatedCast(long value) { if (value > Short.MAX_VALUE) { return Short.MAX_VALUE; } if (value < Short.MIN_VALUE) { return Short.MIN_VALUE; } return (short) value; } /** * Compares the two specified {@code short} values. The sign of the value * returned is the same as that of {@code ((Short) a).compareTo(b)}. * *
Note: projects using JDK 7 or later should use the equivalent * {@link Short#compare} method instead. * * @param a the first {@code short} to compare * @param b the second {@code short} to compare * @return a negative value if {@code a} is less than {@code b}; a positive * value if {@code a} is greater than {@code b}; or zero if they are equal */ public static int compare(short a, short b) { return a - b; // safe due to restricted range } /** * Returns {@code true} if {@code target} is present as an element anywhere in * {@code array}. * * @param array an array of {@code short} values, possibly empty * @param target a primitive {@code short} value * @return {@code true} if {@code array[i] == target} for some value of {@code * i} */ public static boolean contains(short[] array, short target) { for (short value : array) { if (value == target) { return true; } } return false; } /** * Returns the index of the first appearance of the value {@code target} in * {@code array}. * * @param array an array of {@code short} values, possibly empty * @param target a primitive {@code short} value * @return the least index {@code i} for which {@code array[i] == target}, or * {@code -1} if no such index exists. */ public static int indexOf(short[] array, short target) { return indexOf(array, target, 0, array.length); } // TODO(kevinb): consider making this public private static int indexOf( short[] array, short target, int start, int end) { for (int i = start; i < end; i++) { if (array[i] == target) { return i; } } return -1; } /** * Returns the start position of the first occurrence of the specified {@code * target} within {@code array}, or {@code -1} if there is no such occurrence. * *
More formally, returns the lowest index {@code i} such that {@code
* java.util.Arrays.copyOfRange(array, i, i + target.length)} contains exactly
* the same elements as {@code target}.
*
* @param array the array to search for the sequence {@code target}
* @param target the array to search for as a sub-sequence of {@code array}
*/
public static int indexOf(short[] array, short[] target) {
checkNotNull(array, "array");
checkNotNull(target, "target");
if (target.length == 0) {
return 0;
}
outer:
for (int i = 0; i < array.length - target.length + 1; i++) {
for (int j = 0; j < target.length; j++) {
if (array[i + j] != target[j]) {
continue outer;
}
}
return i;
}
return -1;
}
/**
* Returns the index of the last appearance of the value {@code target} in
* {@code array}.
*
* @param array an array of {@code short} values, possibly empty
* @param target a primitive {@code short} value
* @return the greatest index {@code i} for which {@code array[i] == target},
* or {@code -1} if no such index exists.
*/
public static int lastIndexOf(short[] array, short target) {
return lastIndexOf(array, target, 0, array.length);
}
// TODO(kevinb): consider making this public
private static int lastIndexOf(
short[] array, short target, int start, int end) {
for (int i = end - 1; i >= start; i--) {
if (array[i] == target) {
return i;
}
}
return -1;
}
/**
* Returns the least value present in {@code array}.
*
* @param array a nonempty array of {@code short} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static short min(short... array) {
checkArgument(array.length > 0);
short min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a nonempty array of {@code short} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static short max(short... array) {
checkArgument(array.length > 0);
short max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* Returns the values from each provided array combined into a single array.
* For example, {@code concat(new short[] {a, b}, new short[] {}, new
* short[] {c}} returns the array {@code {a, b, c}}.
*
* @param arrays zero or more {@code short} arrays
* @return a single array containing all the values from the source arrays, in
* order
*/
public static short[] concat(short[]... arrays) {
int length = 0;
for (short[] array : arrays) {
length += array.length;
}
short[] result = new short[length];
int pos = 0;
for (short[] array : arrays) {
System.arraycopy(array, 0, result, pos, array.length);
pos += array.length;
}
return result;
}
private static final class ShortConverter
extends Converter The returned comparator is inconsistent with {@link
* Object#equals(Object)} (since arrays support only identity equality), but
* it is consistent with {@link Arrays#equals(short[], short[])}.
*
* @see
* Lexicographical order article at Wikipedia
* @since 2.0
*/
public static Comparator Elements are copied from the argument collection as if by {@code
* collection.toArray()}. Calling this method is as thread-safe as calling
* that method.
*
* @param collection a collection of {@code Number} instances
* @return an array containing the same values as {@code collection}, in the
* same order, converted to primitives
* @throws NullPointerException if {@code collection} or any of its elements
* is null
* @since 1.0 (parameter was {@code Collection The returned list maintains the values, but not the identities, of
* {@code Short} objects written to or read from it. For example, whether
* {@code list.get(0) == list.get(0)} is true for the returned list is
* unspecified.
*
* @param backingArray the array to back the list
* @return a list view of the array
*/
public static List