public void ShouldExtenedLinkedListByFindAllMethod()
{
// given
IEnumerable <int> list = Lists.AsLinkedList(Lists.AsList(1, 2, 3, 4));
Predicate <int> filter = item => item % 2 == 0;
// when
var filtered = list.FindAll(filter);
// then
Check.That(filtered).IsInstanceOf <LinkedList <int> >();
Check.That(filtered).ContainsExactly(2, 4);
}
/// <summary>
/// Returns filtered collection items by given predicate.
/// </summary>
/// <typeparam name="T">Type of collection item</typeparam>
/// <param name="source">this</param>
/// <param name="filter">Item filter</param>
/// <returns>Filtered collection</returns>
public static IEnumerable <T> FindAll <T>(this IEnumerable <T> source, Predicate <T> filter)
{
Preconditions.IsNotNull(source, () => new ArgumentNullException("source"));
if (source is List <T> )
{
return(((List <T>)source).FindAll(filter));
}
if (source is ISet <T> )
{
return(FindAll((ISet <T>)source, filter));
}
var filtered = source.Where(item => filter(item)).ToList();
if (source is LinkedList <T> )
{
return(Lists.AsLinkedList(filtered));
}
return(filtered);
}
protected override ICollection <TValue> ResultCollection(ICollection <TValue> collection)
{
return(Lists.AsLinkedList(collection));
}