ArrayFill.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
*
* https://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 org.apache.commons.lang3;
import java.util.Arrays;
import java.util.function.IntFunction;
import org.apache.commons.lang3.function.FailableIntFunction;
/**
* Fills and returns arrays in the fluent style.
*
* @since 3.14.0
*/
public final class ArrayFill {
/**
* Fills and returns the given array, assigning {@code 0} to each element of the array.
* <pre>
* ArrayFill.fill(a, (byte) 0);
* </pre>
*
* @param a the array to fill (may be null).
* @return the given array.
* @see Arrays#fill(byte[],byte)
* @see ArrayFill#fill(byte[],byte)
* @since 3.21.0
*/
public static byte[] clear(final byte[] a) {
return fill(a, (byte) 0);
}
/**
* Fills and returns the given array, assigning {@code '\0'} to each element of the array.
* <p>
* Equivalent to:
* </p>
* <pre>
* ArrayFill.fill(a, '\0'); // and not '0'!
* </pre>
*
* @param a the array to fill (may be null).
* @return the given array.
* @see Arrays#fill(char[],char)
* @see ArrayFill#fill(char[],char)
* @see CharUtils#NUL
* @since 3.21.0
*/
public static char[] clear(final char[] a) {
return fill(a, CharUtils.NUL); // and not '0'!
}
/**
* Fills and returns the given array, assigning {@code '\0'} to each element of the array.
* <p>
* Equivalent to:
* </p>
* <pre>
* ArrayFill.fill(a, fromIndex, toIndex, '\0'); // and not '0'!
* </pre>
*
* @param a the array to fill (may be null).
* @param fromIndex the index of the first element (inclusive) to be filled with {@code '\0'}.
* @param toIndex the index of the last element (exclusive) to be filled with {@code '\0'}.
* @return the given array.
* @see Arrays#fill(char[], int, int, char)
* @since 3.21.0
*/
public static char[] clear(char[] a, int fromIndex, int toIndex) {
return fill(a, fromIndex, toIndex, CharUtils.NUL);
}
/**
* Fills and returns the given array, assigning the given {@code boolean} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(boolean[],boolean)
* @since 3.18.0
*/
public static boolean[] fill(final boolean[] a, final boolean val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code byte} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(byte[],byte)
*/
public static byte[] fill(final byte[] a, final byte val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code char} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(char[],char)
*/
public static char[] fill(final char[] a, final char val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code char} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @param fromIndex the index of the first element (inclusive) to be filled with the specified value.
* @param toIndex the index of the last element (exclusive) to be filled with the specified value.
* @return the given array.
* @see Arrays#fill(char[], int, int, char)
* @since 3.21.0
*/
public static char[] fill(char[] a, int fromIndex, int toIndex, char val) {
if (a != null) {
Arrays.fill(a, fromIndex, toIndex, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code double} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(double[],double)
*/
public static double[] fill(final double[] a, final double val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code float} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(float[],float)
*/
public static float[] fill(final float[] a, final float val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code int} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(int[],int)
*/
public static int[] fill(final int[] a, final int val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code long} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(long[],long)
*/
public static long[] fill(final long[] a, final long val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, assigning the given {@code short} value to each element of the array.
*
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(short[],short)
*/
public static short[] fill(final short[] a, final short val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
/**
* Fills and returns the given array, using the provided generator function to compute each element. Like {@link Arrays#setAll(Object[], IntFunction)} with
* exception support.
* <p>
* If the generator function throws an exception, it is relayed to the caller and the array is left in an indeterminate state.
* </p>
* <p>
* If the input array or generator function is null, nothing happens.
* </p>
*
* @param <T> type of elements of the array.
* @param array array to fill (may be null).
* @param generator a function accepting an index and producing the desired value for that position.
* @return the input array.
* @param <E> The kind of thrown exception or error.
* @throws E Thrown by the given {@code generator}.
* @see Arrays#setAll(Object[], IntFunction)
* @since 3.18.0
*/
public static <T, E extends Throwable> T[] fill(final T[] array, final FailableIntFunction<? extends T, E> generator) throws E {
if (array != null && generator != null) {
for (int i = 0; i < array.length; i++) {
array[i] = generator.apply(i);
}
}
return array;
}
/**
* Fills and returns the given array, assigning the given {@code T} value to each element of the array.
*
* @param <T> the array type.
* @param a the array to fill (may be null).
* @param val the value to store in all elements of the array.
* @return the given array.
* @see Arrays#fill(Object[],Object)
*/
public static <T> T[] fill(final T[] a, final T val) {
if (a != null) {
Arrays.fill(a, val);
}
return a;
}
private ArrayFill() {
// no instances
}
}