Class EnumerableExtensions

Provides extension methods for IEnumerable<T>s.

Inheritance

Object

EnumerableExtensions

Namespace: NanoByte.Common.Collections

Assembly: NanoByte.Common.dll

Syntax

public static class EnumerableExtensions : Object

Methods

CloneElements<T>(IEnumerable<T>)

Calls Clone() for every element in a enumeration and returns the results as a new enumeration.

Declaration

public static IEnumerable<T> CloneElements<T>(this IEnumerable<T> enumerable)
    where T : ICloneable<T>

Parameters

Type	Name	Description
IEnumerable<T>	enumerable

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

ContainsAny<T>(IEnumerable<T>, IEnumerable<T>, IEqualityComparer<T>)

Determines whether one enumeration of elements contains any of the elements in another.

Declaration

public static bool ContainsAny<T>(this IEnumerable<T> first, IEnumerable<T> second, IEqualityComparer<T> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	first	The first of the two enumerations to compare.
IEnumerable<T>	second	The first of the two enumerations to compare.
System.Collections.Generic.IEqualityComparer<T>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
Boolean	true if first contains any element from second. false if first or second is empty.

Type Parameters

Name	Description
T

ContainsOrEmpty<T>(IEnumerable<T>, T)

Determines whether the enumeration contains an element or is null.

Declaration

public static bool ContainsOrEmpty<T>(this IEnumerable<T> enumeration, T element)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration	The list to check.
T	element	The element to look for.

Returns

Type	Description
Boolean

Type Parameters

Name	Description
T

Remarks

Useful for lists that contain an OR-ed list of restrictions, where an empty list means no restrictions.

DistinctBy<T, TKey>(IEnumerable<T>, Func<T, TKey>)

Filters a sequence of elements to remove any duplicates based on the equality of a key extracted from the elements.

Declaration

public static IEnumerable<T> DistinctBy<T, TKey>(this IEnumerable<T> enumeration, Func<T, TKey> keySelector)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration	The sequence of elements to filter.
Func<T, TKey>	keySelector	A function mapping elements to their respective equality keys.

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T
TKey

Except<T>(IEnumerable<T>, T)

Filters a sequence of elements to remove any that are equal to element.

Declaration

public static IEnumerable<T> Except<T>(this IEnumerable<T> enumeration, T element)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration
T	element

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

Except<T>(IEnumerable<T>, Func<T, Boolean>)

Filters a sequence of elements to remove any that match the predicate. The opposite of System.Linq.Enumerable.Where``1(System.Collections.Generic.IEnumerable{``0},System.Func{``0,System.Boolean}).

Declaration

public static IEnumerable<T> Except<T>(this IEnumerable<T> enumeration, Func<T, bool> predicate)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration
Func<T, Boolean>	predicate

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

Flatten<T>(IEnumerable<IEnumerable<T>>)

Flattens a list of lists.

Declaration

public static IEnumerable<T> Flatten<T>(this IEnumerable<IEnumerable<T>> enumeration)

Parameters

Type	Name	Description
IEnumerable<IEnumerable<T>>	enumeration

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

GetSequencedHashCode<T>(IEnumerable<T>, IEqualityComparer<T>)

Generates a hash code for the contents of the enumeration. Changing the elements' order will change the hash.

Declaration

public static int GetSequencedHashCode<T>(this IEnumerable<T> enumeration, IEqualityComparer<T> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration	The enumeration to generate the hash for.
System.Collections.Generic.IEqualityComparer<T>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
Int32

Type Parameters

Name	Description
T

See Also

SequencedEquals<T>(IEnumerable<T>, IEnumerable<T>, IEqualityComparer<T>)

GetUnsequencedHashCode<T>(IEnumerable<T>, IEqualityComparer<T>)

Generates a hash code for the contents of the enumeration. Changing the elements' order will not change the hash.

Declaration

public static int GetUnsequencedHashCode<T>(this IEnumerable<T> enumeration, IEqualityComparer<T> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration	The enumeration to generate the hash for.
System.Collections.Generic.IEqualityComparer<T>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
Int32

Type Parameters

Name	Description
T

See Also

UnsequencedEquals<T>(IEnumerable<T>, IEnumerable<T>, IEqualityComparer<T>)

MaxBy<T, TValue>(IEnumerable<T>, Func<T, TValue>, IComparer<TValue>)

Determines the element in a list that maximizes a specified expression.

Declaration

public static T MaxBy<T, TValue>(this IEnumerable<T> enumeration, Func<T, TValue> expression, IComparer<TValue> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration	The elements to check.
Func<T, TValue>	expression	The expression to maximize.
IComparer<TValue>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
T	The element that maximizes the expression.

Type Parameters

Name	Description
T	The type of the elements.
TValue	The type of the expression.

Exceptions

Type	Condition
InvalidOperationException	enumeration contains no elements.

MinBy<T, TValue>(IEnumerable<T>, Func<T, TValue>, IComparer<TValue>)

Determines the element in a list that minimizes a specified expression.

Declaration

public static T MinBy<T, TValue>(this IEnumerable<T> enumeration, Func<T, TValue> expression, IComparer<TValue> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	enumeration	The elements to check.
Func<T, TValue>	expression	The expression to minimize.
IComparer<TValue>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
T	The element that minimizes the expression.

Type Parameters

Name	Description
T	The type of the elements.
TValue	The type of the expression.

Exceptions

Type	Condition
InvalidOperationException	enumeration contains no elements.

Permutate<T>(IEnumerable<T>)

Generates all possible permutations of a set of elements.

Declaration

public static IEnumerable<T[]> Permutate<T>(this IEnumerable<T> elements)

Parameters

Type	Name	Description
IEnumerable<T>	elements

Returns

Type	Description
IEnumerable<T[]>

Type Parameters

Name	Description
T

SequencedEquals<T>(IEnumerable<T>, IEnumerable<T>, IEqualityComparer<T>)

Determines whether two enumerations contain the same elements in the same order.

Declaration

public static bool SequencedEquals<T>(this IEnumerable<T> first, IEnumerable<T> second, IEqualityComparer<T> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	first	The first of the two enumerations to compare.
IEnumerable<T>	second	The first of the two enumerations to compare.
System.Collections.Generic.IEqualityComparer<T>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
Boolean

Type Parameters

Name	Description
T

TopologicalSort<T>(IEnumerable<T>, Func<T, IEnumerable<T>>)

Performs a topological sort of an object graph.

Declaration

public static IEnumerable<T> TopologicalSort<T>(this IEnumerable<T> nodes, Func<T, IEnumerable<T>> getDependencies)

Parameters

Type	Name	Description
IEnumerable<T>	nodes	The set of nodes to sort.
Func<T, IEnumerable<T>>	getDependencies	A function that retrieves all dependencies of a node.

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

Exceptions

Type	Condition
System.IO.InvalidDataException	Cyclic dependency found.

TrySelect<TSource, TResult, TException>(IEnumerable<TSource>, Func<TSource, TResult>, Action<TException>)

Maps elements using a selector. Calls a handler for specific exceptions, skips the element and continues enumerating with the element.

Declaration

public static IEnumerable<TResult> TrySelect<TSource, TResult, TException>(this IEnumerable<TSource> source, Func<TSource, TResult> selector, Action<TException> exceptionHandler)
    where TException : Exception

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The elements to map.
Func<TSource, TResult>	selector	The selector to execute for each source element.
Action<TException>	exceptionHandler	A Callback to be invoked when a TException is caught.

Returns

Type	Description
IEnumerable<TResult>

Type Parameters

Name	Description
TSource	The type of the input elements.
TResult	The type of the output elements.
TException	The type of exceptions to handle..

UnsequencedEquals<T>(IEnumerable<T>, IEnumerable<T>, IEqualityComparer<T>)

Determines whether two enumerations contain the same elements disregarding the order they are in.

Declaration

public static bool UnsequencedEquals<T>(this IEnumerable<T> first, IEnumerable<T> second, IEqualityComparer<T> comparer = null)

Parameters

Type	Name	Description
IEnumerable<T>	first	The first of the two enumerations to compare.
IEnumerable<T>	second	The first of the two enumerations to compare.
System.Collections.Generic.IEqualityComparer<T>	comparer	Controls how to compare elements; leave null for default comparer.

Returns

Type	Description
Boolean

Type Parameters

Name	Description
T

WhereNotNull<T>(IEnumerable<T>)

Filters a sequence of elements to remove any null values.

Declaration

public static IEnumerable<T> WhereNotNull<T>(this IEnumerable<T> enumeration)
    where T : class

Parameters

Type	Name	Description
IEnumerable<T>	enumeration

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T