Class Collection

Provides utility methods to work with collections.

Inheritance

object

Collection

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: DotNext.Collections.Generic

Assembly: DotNext.dll

Syntax

public static class Collection

Methods

AddAll<T>(ICollection<T>, IEnumerable<T>)

Adds multiple items into collection.

Declaration

public static void AddAll<T>(this ICollection<T> collection, IEnumerable<T> items)

Parameters

Type	Name	Description
ICollection<T>	collection	A collection to modify.
IEnumerable<T>	items	An items to add into collection.

Type Parameters

Name	Description
T	The type of elements in the collection.

Append<T>(IEnumerable<T>, params T[])

Adds items to the end of collection.

Declaration

public static IEnumerable<T> Append<T>(this IEnumerable<T> collection, params T[] items)

Parameters

Type	Name	Description
IEnumerable<T>	collection	The collection to be concatenated with the items.
T[]	items	The items to be added to the end of the collection.

Returns

Type	Description
IEnumerable<T>	The concatenated collection.

Type Parameters

Name	Description
T	The type of items in the collection.

Convert<TInput, TOutput>(IReadOnlyCollection<TInput>, Converter<TInput, TOutput>)

Returns lazily converted read-only collection.

Declaration

public static ReadOnlyCollectionView<TInput, TOutput> Convert<TInput, TOutput>(this IReadOnlyCollection<TInput> collection, Converter<TInput, TOutput> converter)

Parameters

Type	Name	Description
IReadOnlyCollection<TInput>	collection	Read-only collection to convert.
Converter<TInput, TOutput>	converter	A collection item conversion function.

Returns

Type	Description
ReadOnlyCollectionView<TInput, TOutput>	Lazily converted read-only collection.

Type Parameters

Name	Description
TInput	Type of items in the source collection.
TOutput	Type of items in the target collection.

Copy<T>(IEnumerable<T>, int, MemoryAllocator<T>?)

Creates a copy of the elements from the collection.

Declaration

public static MemoryOwner<T> Copy<T>(this IEnumerable<T> enumerable, int sizeHint = 0, MemoryAllocator<T>? allocator = null)

Parameters

Type	Name	Description
IEnumerable<T>	enumerable	The collection to copy.
int	sizeHint	The approximate size of the collection, if known.
MemoryAllocator<T>	allocator	The allocator of the memory block used to place copied elements.

Returns

Type	Description
MemoryOwner<T>	Rented memory block containing a copy of the elements from the collection.

Type Parameters

Name	Description
T	The type of elements in the collection.

Exceptions

Type	Condition
ArgumentNullException	enumerable is null.
ArgumentOutOfRangeException	sizeHint is less than zero.

ElementAt<T>(IEnumerable<T>, int, out T)

Obtains element at the specified index in the sequence.

Declaration

public static bool ElementAt<T>(this IEnumerable<T> collection, int index, out T element)

Parameters

Type	Name	Description
IEnumerable<T>	collection	Source collection.
int	index	Index of the element to read.
T	element	Obtained element.

Returns

Type	Description
bool	true, if element is available in the collection and obtained successfully; otherwise, false.

Type Parameters

Name	Description
T	Type of elements in the sequence.

Remarks

This method is optimized for types IList<T> and IReadOnlyList<T>.

FirstOrNone<T>(IEnumerable<T>)

Obtains the first element of a sequence; or None if the sequence is empty.

Declaration

public static Optional<T> FirstOrNone<T>(this IEnumerable<T> collection)

Parameters

Type	Name	Description
IEnumerable<T>	collection	The collection to return the first element of.

Returns

Type	Description
Optional<T>	The first element; or None

Type Parameters

Name	Description
T	The type of the element of a collection.

ForEachAsync<T>(IEnumerable<T>, Func<T, CancellationToken, ValueTask>, CancellationToken)

Applies the specified asynchronous action to each collection element.

Declaration

public static ValueTask ForEachAsync<T>(this IEnumerable<T> collection, Func<T, CancellationToken, ValueTask> action, CancellationToken token = default)

Parameters

Type	Name	Description
IEnumerable<T>	collection	A collection to enumerate. Cannot be null.
Func<T, CancellationToken, ValueTask>	action	An action to applied for each element.
CancellationToken	token	The token that can be used to cancel the enumeration.

Returns

Type	Description
ValueTask	The task representing asynchronous execution of this method.

Type Parameters

Name	Description
T	Type of elements in the collection.

Exceptions

Type	Condition
OperationCanceledException	The enumeration has been canceled.

ForEach<T>(IEnumerable<T>, Action<T>)

Applies specified action to each collection element.

Declaration

public static void ForEach<T>(this IEnumerable<T> collection, Action<T> action)

Parameters

Type	Name	Description
IEnumerable<T>	collection	A collection to enumerate. Cannot be null.
Action<T>	action	An action to applied for each element.

Type Parameters

Name	Description
T	Type of elements in the collection.

GetConsumer<T>(IProducerConsumerCollection<T>)

Gets consumer of thread-safe concurrent collection.

Declaration

public static Collection.ConsumingEnumerable<T> GetConsumer<T>(this IProducerConsumerCollection<T> collection)

Parameters

Type	Name	Description
IProducerConsumerCollection<T>	collection	The concurrent collection.

Returns

Type	Description
Collection.ConsumingEnumerable<T>	The consumer in the form of enumerable collection.

Type Parameters

Name	Description
T	The type of elements in the collection.

LastOrNone<T>(IEnumerable<T>)

Obtains the last element of a sequence; or None if the sequence is empty.

Declaration

public static Optional<T> LastOrNone<T>(this IEnumerable<T> collection)

Parameters

Type	Name	Description
IEnumerable<T>	collection	The collection to return the first element of.

Returns

Type	Description
Optional<T>	The first element; or None

Type Parameters

Name	Description
T	The type of the element of a collection.

Prepend<T>(IEnumerable<T>, params T[])

Adds items to the beginning of collection.

Declaration

public static IEnumerable<T> Prepend<T>(this IEnumerable<T> collection, params T[] items)

Parameters

Type	Name	Description
IEnumerable<T>	collection	The collection to be concatenated with the items.
T[]	items	The items to be added to the beginning of the collection.

Returns

Type	Description
IEnumerable<T>	The concatenated collection.

Type Parameters

Name	Description
T	The type of items in the collection.

SequenceHashCode<T>(IEnumerable<T>, bool)

Computes hash code for the sequence of objects.

Declaration

public static int SequenceHashCode<T>(this IEnumerable<T> sequence, bool salted = true)

Parameters

Type	Name	Description
IEnumerable<T>	sequence	The sequence of elements.
bool	salted	true to include randomized salt data into hashing; false to use data from memory only.

Returns

Type	Description
int	The hash code computed from each element in the sequence.

Type Parameters

Name	Description
T	Type of the elements in the sequence.

SkipNulls<T>(IEnumerable<T?>)

Skip null values in the collection.

Declaration

public static IEnumerable<T> SkipNulls<T>(this IEnumerable<T?> collection) where T : class

Parameters

Type	Name	Description
IEnumerable<T>	collection	A collection to check. Cannot be null.

Returns

Type	Description
IEnumerable<T>	Modified lazy collection without null values.

Type Parameters

Name	Description
T	Type of elements in the collection.

ToArray<T>(ICollection<T>)

Converts collection into single-dimensional array.

Declaration

public static T[] ToArray<T>(ICollection<T> collection)

Parameters

Type	Name	Description
ICollection<T>	collection	A collection to convert.

Returns

Type	Description
T[]	Array of collection items.

Type Parameters

Name	Description
T	Type of collection items.

ToArray<T>(IReadOnlyCollection<T>)

Converts read-only collection into single-dimensional array.

Declaration

public static T[] ToArray<T>(IReadOnlyCollection<T> collection)

Parameters

Type	Name	Description
IReadOnlyCollection<T>	collection	A collection to convert.

Returns

Type	Description
T[]	Array of collection items.

Type Parameters

Name	Description
T	Type of collection items.

ToAsyncEnumerable<T>(IEnumerable<T>)

Converts synchronous collection of elements to asynchronous.

Declaration

public static IAsyncEnumerable<T> ToAsyncEnumerable<T>(this IEnumerable<T> enumerable)

Parameters

Type	Name	Description
IEnumerable<T>	enumerable	The collection of elements.

Returns

Type	Description
IAsyncEnumerable<T>	The asynchronous wrapper over synchronous collection of elements.

Type Parameters

Name	Description
T	The type of the elements in the collection.

Exceptions

Type	Condition
ArgumentNullException	enumerable is null.

ToAsyncEnumerator<TEnumerator, T>(TEnumerator, CancellationToken)

Converts ad-hoc enumerator to a generic enumerator.

Declaration

public static IAsyncEnumerator<T> ToAsyncEnumerator<TEnumerator, T>(this TEnumerator enumerator, CancellationToken token) where TEnumerator : struct, IEnumerator<TEnumerator, T>

Parameters

Type	Name	Description
TEnumerator	enumerator	Ad-hoc enumerator.
CancellationToken	token	The token that can be used to cancel the enumeration.

Returns

Type	Description
IAsyncEnumerator<T>	The enumerator over values of type T.

Type Parameters

Name	Description
TEnumerator
T

ToClassicEnumerator<TEnumerator, T>(TEnumerator)

Converts ad-hoc enumerator to a generic enumerator.

Declaration

public static IEnumerator<T> ToClassicEnumerator<TEnumerator, T>(this TEnumerator enumerator) where TEnumerator : struct, IEnumerator<TEnumerator, T>

Parameters

Type	Name	Description
TEnumerator	enumerator	Ad-hoc enumerator.

Returns

Type	Description
IEnumerator<T>	The enumerator over values of type T.

Type Parameters

Name	Description
TEnumerator
T

ToString<T>(IEnumerable<T>, string, string)

Concatenates each element from the collection into single string.

Declaration

public static string ToString<T>(this IEnumerable<T> collection, string delimiter, string ifEmpty = "")

Parameters

Type	Name	Description
IEnumerable<T>	collection	Collection to convert. Cannot be null.
string	delimiter	Delimiter between elements in the final string.
string	ifEmpty	A string to be returned if collection has no elements.

Returns

Type	Description
string	Converted collection into string.

Type Parameters

Name	Description
T	Type of array elements.