AbbLab.Collections 2.2.1

AbbLab.Collections

Provides various collection-related extension and utility methods.

ArrayExtensions

Contains extension versions of most static methods in the Array class.

int[] numbers = new int[10] { 1, 1, 2, 3, 5, 8, 13, 21, 34, 55 };

int index = numbers.IndexOf(8);

string[] strings = numbers.ConvertAll(num => num.ToString());

string? found = strings.Find(s => s.Length > 1);

Includes overloads of Find, Exists, ConvertAll and other methods that use delegates, that provide one or two extra parameters - the element's index and the source array. Similar to how it works in JavaScript arrays.

string[] distinct = strings.FindAll((el, i, arr) => i == arr.IndexOf(el));

Also includes some common LINQ methods adapted for arrays: Cast, OfType and Contains. And Copy for simpler shallow copying.

object[] arr = new object[] { "Hello", "World", "!" };

string[] strings = arr.Cast<string>();

object[] shallowCopy = arr.Copy();

CollectionExtensions

Contains Add overloads for adding tuples and KeyValuePairs to collections, without having to enclose the elements in double parenthesis.

List<(string, double)> units = new();

units.Add("meter", 1);
units.Add("centimeter", 0.01);

Contains shims for AsReadOnly extension methods (introduced in .NET 7) for .NET 6 and earlier versions.

EnumerableExtensions

Contains NotNull and ForEach extension methods for enumerables.

string?[] values = new string?[] { "Hello", null, " World", null, "!\n" };

values.NotNull().ForEach(word => Console.Write(word));

Enumerator, ReadOnlyCollection, ReadOnlyDictionary

Contain static Empty<T>() methods that returns a global empty enumerator/read-only collection/read-only dictionary.

if (size == 0) return ReadOnlyCollection.Empty<string>();
/* ... */

Enumerator contains three versions of this method: Empty() (IEnumerator), Empty<T>() (IEnumerator<T>) and EmptyAsync<T>() (IAsyncEnumerator<T>).

CompleteComparer<T>

Implements the ICompleteComparer<T> interface, which in turn implements IComparer, IComparer<T>, IEqualityComparer and IEqualityComparer<T>.

CompleteComparer<T> comparer = CompleteComparer<T>.Default;

bool equal = comparer.Equals(x, y);
int comparison = comparer.Compare(x, y);

The ICompleteComparer<T> interface can be used as a shorthand when implementing your own complex multi-typed comparers. When your comparer handles only a single type, you should derive from the CompleteComparer<T> class instead.