/// <summary>
/// Repeats a list of values a specified number of times.
/// </summary>
/// <typeparam name="T">The type of object contained in the list.</typeparam>
/// <param name="list">The list of values to repeat.</param>
/// <param name="count">The number of times to repeat all elements in the source list. If <paramref name="count"/> is less than or equal to 0, an empty list is returned.</param>
/// <returns>A list containing the source list repeated the specified number of times.</returns>
public static IList <T> Repeat <T>(this IList <T> list, int count)
{
if (count <= 0)
{
return(ListSource.Empty <T>());
}
return(new Implementation.AnonymousReadOnlyList <T>(i => list[i % list.Count], () => list.Count * count));
}
/// <summary>
/// Returns a read-only list that generates its elements when they are read, passing the element's index to the generator delegate.
/// </summary>
/// <typeparam name="T">The type of elements in the list.</typeparam>
/// <param name="generator">The delegate that is used to generate the elements. This may be <c>null</c> if <paramref name="count"/> is less than or equal to 0.</param>
/// <param name="count">The number of elements in the list. If <paramref name="count"/> is less than or equal to 0, an empty list is returned.</param>
/// <returns>A read-only list that generates its elements on demand.</returns>
public static IList <T> Generate <T>(Func <int, T> generator, int count)
{
if (count <= 0)
{
return(ListSource.Empty <T>());
}
return(new Implementation.AnonymousReadOnlyList <T>(generator, () => count));
}
/// <summary>
/// Converts a single value into a list containing that value the specified number of times.
/// </summary>
/// <typeparam name="T">The type of the value.</typeparam>
/// <param name="source">The value.</param>
/// <param name="count">The number of times <paramref name="source"/> is repeated. If <paramref name="count"/> is less than or equal to 0, an empty list is returned.</param>
/// <returns>A read-only list containing <paramref name="count"/> elements, all equal to <paramref name="source"/>.</returns>
public static IList <T> Repeat <T>(T source, int count)
{
if (count <= 0)
{
return(ListSource.Empty <T>());
}
return(new Implementation.AnonymousReadOnlyList <T>(_ => source, () => count));
}
/// <summary>
/// Returns a sliced list, which acts as a window into a subset of the original list.
/// </summary>
/// <typeparam name="T">The type of object contained in the list.</typeparam>
/// <param name="list">The list to slice.</param>
/// <param name="count">The number of elements in the slice. If <paramref name="count"/> is less than or equal to zero, then an empty list is returned; if <paramref name="count"/> is greater than or equal to the count of the source list, then a list equivalent to the source list is returned.</param>
/// <returns>A list that is a slice of the source list.</returns>
public static IList <T> Take <T>(this IList <T> list, int count)
{
if (count <= 0)
{
return(ListSource.Empty <T>());
}
if (count >= list.Count)
{
return(list);
}
return(new SliceList <T>(list, 0, count));
}
/// <summary>
/// Returns a sliced list, which acts as a window into a subset of the original list.
/// </summary>
/// <typeparam name="T">The type of object contained in the list.</typeparam>
/// <param name="list">The list to slice.</param>
/// <param name="offset">The offset into the list at which the slice begins. If <paramref name="offset"/> is less than or equal to zero, then a list equivalent to the source list is returned; if <paramref name="offset"/> is greater than or equal to the count of the source list, then an empty list is returned.</param>
/// <returns>A list that is a slice of the source list.</returns>
public static IList <T> Skip <T>(this IList <T> list, int offset)
{
if (offset <= 0)
{
return(list);
}
if (offset >= list.Count)
{
return(ListSource.Empty <T>());
}
return(new SliceList <T>(list, offset, list.Count - offset));
}
/// <summary>
/// Creates an empty sorted list. The list is sorted by the specified comparison delegate.
/// </summary>
/// <typeparam name="T">The type of items in the list.</typeparam>
/// <param name="comparer">The comparison delegate.</param>
/// <returns>An empty sorted list.</returns>
public static ISortedList <T> Empty <T>(Func <T, T, int> comparer)
{
return(new SortedListWrapper <T>(ListSource.Empty <T>(), A.Comparer(comparer)));
}
/// <summary>
/// Creates an empty sorted list. The list is sorted by the default comparison object.
/// </summary>
/// <typeparam name="T">The type of items in the list.</typeparam>
/// <returns>An empty sorted list.</returns>
public static ISortedList <T> Empty <T>()
{
return(new SortedListWrapper <T>(ListSource.Empty <T>(), Comparer <T> .Default));
}
/// <summary>
/// Creates an empty sorted list. The list is sorted by the specified comparison object.
/// </summary>
/// <typeparam name="T">The type of items in the list.</typeparam>
/// <param name="comparer">The comparison object.</param>
/// <returns>An empty sorted list.</returns>
public static ISortedList <T> Empty <T>(IComparer <T> comparer)
{
return(new SortedListWrapper <T>(ListSource.Empty <T>(), comparer));
}