/// <summary>
/// Returns a copy of the given <see cref="IEnumerable{T}"/> that is shuffled using the Fisher-Yates algorithm.
/// </summary>
/// <typeparam name="T">The type of the items in the <see cref="IEnumerable{T}"/>.</typeparam>
/// <param name="source">The <see cref="IEnumerable{T}"/> to copy.</param>
/// <param name="rand">The <see cref="Random"/> to use for number generation. Uses <see cref="TSRandom"/> if <see langword="null"/>.</param>
public static IEnumerable <T> Shuffle <T>(this IEnumerable <T> source, Random rand = null)
{
GenericExtensions.ThrowIfNull(source, nameof(source));
rand ??= TSRandom.Instance; // Thread-safe random
return(source.ShuffleIterator(rand));
}
/// <summary>
/// Returns the given array with the specified object added to the end.
/// </summary>
/// <typeparam name="T">The type of objects contained within the array.</typeparam>
/// <param name="array">The array to add to.</param>
/// <param name="item">The object to be added to the end of the array. The value can be null for reference types.</param>
/// <returns></returns>
public static T[] Add <T>(this T[] array, T item)
{
GenericExtensions.ThrowIfNull(array, nameof(array));
int oldLen = array.Length;
Array.Resize(ref array, oldLen + 1);
array[oldLen] = item;
return(array);
}
/// <summary>
/// Returns a new, combined array from the given arrays.
/// </summary>
/// <typeparam name="T">The type of the array.</typeparam>
/// <param name="array">The first array to concatenate.</param>
/// <param name="arrays">The additional arrays to concatenate.</param>
/// <returns></returns>
public static T[] Concat <T>(this T[] array, params T[][] arrays)
{
GenericExtensions.ThrowIfNull(array, nameof(array));
GenericExtensions.ThrowIfNull(arrays, nameof(arrays));
int offset = array.Length;
Array.Resize(ref array, array.Length + arrays.Sum(a => a.Length));
foreach (T[] arr in arrays)
{
int len = arr.Length;
Array.Copy(arr, 0, array, offset, len);
offset += len;
}
return(array);
}
/// <summary>
/// Returns the given array with the first occurence of the specified object removed.
/// </summary>
/// <typeparam name="T">The type of items contained within the array.</typeparam>
/// <param name="array">The array to remove from.</param>
/// <param name="item">The object to remove from the array. The value can be null for reference types.</param>
/// <returns></returns>
public static T[] Remove <T>(this T[] array, T item)
{
GenericExtensions.ThrowIfNull(array, nameof(array));
int removeIdx = Array.IndexOf(array, item);
if (removeIdx > array.GetLowerBound(0) - 1)
{
T[] newArray = new T[array.Length - 1];
Array.Copy(array, 0, newArray, 0, removeIdx + 1);
Array.Copy(array, removeIdx + 1, newArray, removeIdx + 1, array.Length - removeIdx);
return(newArray);
}
return(array);
}
