Provides more extension methods for the enumerable types More...

Static Public Member Functions
static IReadOnlyDictionary< K, V >	ToReadOnlyDictionary< K, V > (this IEnumerable< KeyValuePair< K, V >> enumerable)
	Creates a new read-only dictionary from the key value pairs More...

static HashSet< TResult >	ToHashSet< T, TResult > (this IEnumerable< T > enumerable, Func< T, TResult > selector)
	Creates a new HashSet<T> from the elements in the specified enumerable More...

static List< TResult >	ToList< T, TResult > (this IEnumerable< T > enumerable, Func< T, TResult > selector)
	Creates a new IList<T> from the projected elements in the specified enumerable More...

static TResult[]	ToArray< T, TResult > (this IEnumerable< T > enumerable, Func< T, TResult > selector)
	Creates a new array from the projected elements in the specified enumerable More...

static ImmutableArray< TResult >	ToImmutableArray< T, TResult > (this IEnumerable< T > enumerable, Func< T, TResult > selector)
	Creates a new immutable array from the projected elements in the specified enumerable More...

static bool	IsNullOrEmpty< T > (this IEnumerable< T > enumerable)
	Returns true if the specified enumerable is null or has no elements More...

static T	Median< T > (this IEnumerable< T > enumerable)
	Gets the median value in the collection More...

static TProperty	Median< T, TProperty > (this IEnumerable< T > collection, Func< T, TProperty > selector)
	Gets the median value in the collection More...

static int	BinarySearch< TItem, TSearch > (this IList< TItem > list, TSearch value, Func< TSearch, TItem, int > comparer)
	Performs a binary search on the specified collection. More...

static int	BinarySearch< TItem > (this IList< TItem > list, TItem value)
	Performs a binary search on the specified collection. More...

static int	BinarySearch< TItem > (this IList< TItem > list, TItem value, IComparer< TItem > comparer)
	Performs a binary search on the specified collection. More...

static IEnumerable< T >	Memoize< T > (this IEnumerable< T > enumerable)
	Wraps the specified enumerable such that it will only be enumerated once More...

static IEnumerable< T >	Range< T > (T start, T end, Func< T, T > incrementer, bool includeEndPoint=false)
	Produces the an enumerable of the range of values between start and end using the specified incrementing function More...

static IEnumerable< IEnumerable< T > >	GroupAdjacentBy< T > (this IEnumerable< T > enumerable, Func< T, T, bool > grouper)
	Groups adjacent elements of the enumerale using the specified grouper function More...

static bool	AreDifferent< T > (this ISet< T > left, ISet< T > right)
	Determines if there are any differences between the left and right collections. This method uses sets to improve performance and also uses lazy evaluation so if a difference is found, true is immediately returned and evaluation is halted. More...

static IEnumerable< T >	AsEnumerable< T > (this IEnumerator< T > enumerator)
	Converts an IEnumerator<T> to an IEnumerable<T> More...

static V	GetValueOrDefault< K, V > (this IDictionary< K, V > dictionary, K key, V defaultValue=default(V))
	Gets the value associated with the specified key or provided default value if key is not found. More...

static void	DoForEach< T > (this IEnumerable< T > source, Action< T > action)
	Performs an action for each element in collection source More...

Detailed Description

Provides more extension methods for the enumerable types

Definition at line 27 of file LinqExtensions.cs.

Member Function Documentation

◆ ToReadOnlyDictionary< K, V >()

static IReadOnlyDictionary<K, V> QuantConnect.Util.LinqExtensions.ToReadOnlyDictionary< K, V > ( this IEnumerable< KeyValuePair< K, V >> enumerable )

static

Creates a new read-only dictionary from the key value pairs

Template Parameters

K	The key type
V	The value type

Parameters

enumerable The IEnumerable of KeyValuePair instances to convert to a dictionary

Returns: A read-only dictionary holding the same data as the enumerable

Definition at line 36 of file LinqExtensions.cs.

◆ ToHashSet< T, TResult >()

static HashSet<TResult> QuantConnect.Util.LinqExtensions.ToHashSet< T, TResult >	(	this IEnumerable< T >	enumerable,
		Func< T, TResult >	selector
	)

static

Creates a new HashSet<T> from the elements in the specified enumerable

Template Parameters

T	The item type of the source enumerable
TResult	The type of the items in the output HashSet<T>

Parameters

enumerable	The items to be placed into the enumerable
selector	Selects items from the enumerable to be placed into the HashSet<T>

Returns: A new HashSet<T> containing the items in the enumerable

Definition at line 49 of file LinqExtensions.cs.

◆ ToList< T, TResult >()

static List<TResult> QuantConnect.Util.LinqExtensions.ToList< T, TResult >	(	this IEnumerable< T >	enumerable,
		Func< T, TResult >	selector
	)

static

Creates a new IList<T> from the projected elements in the specified enumerable

Template Parameters

T	The item type of the source enumerable
TResult	The type of the items in the output List<T>

Parameters

enumerable	The items to be placed into the list
selector	Selects items from the enumerable to be placed into the List<T>

Returns: A new List<T> containing the items in the enumerable

Definition at line 62 of file LinqExtensions.cs.

◆ ToArray< T, TResult >()

static TResult [] QuantConnect.Util.LinqExtensions.ToArray< T, TResult >	(	this IEnumerable< T >	enumerable,
		Func< T, TResult >	selector
	)

static

Creates a new array from the projected elements in the specified enumerable

Template Parameters

T	The item type of the source enumerable
TResult	The type of the items in the output array

Parameters

enumerable	The items to be placed into the array
selector	Selects items from the enumerable to be placed into the array

Returns: A new array containing the items in the enumerable

Definition at line 75 of file LinqExtensions.cs.

◆ ToImmutableArray< T, TResult >()

static ImmutableArray<TResult> QuantConnect.Util.LinqExtensions.ToImmutableArray< T, TResult >	(	this IEnumerable< T >	enumerable,
		Func< T, TResult >	selector
	)

static

Creates a new immutable array from the projected elements in the specified enumerable

Template Parameters

T	The item type of the source enumerable
TResult	The type of the items in the output array

Parameters

enumerable	The items to be placed into the array
selector	Selects items from the enumerable to be placed into the array

Returns: A new array containing the items in the enumerable

Definition at line 88 of file LinqExtensions.cs.

◆ IsNullOrEmpty< T >()

static bool QuantConnect.Util.LinqExtensions.IsNullOrEmpty< T > ( this IEnumerable< T > enumerable )

static

Returns true if the specified enumerable is null or has no elements

Template Parameters

T	The enumerable's item type

Parameters

enumerable The enumerable to check for a value

Returns: True if the enumerable has elements, false otherwise

Definition at line 99 of file LinqExtensions.cs.

◆ Median< T >()

static T QuantConnect.Util.LinqExtensions.Median< T > ( this IEnumerable< T > enumerable )

static

Gets the median value in the collection

Template Parameters

T	The item type in the collection

Parameters

enumerable The enumerable of items to search

Returns: The median value, throws InvalidOperationException if no items are present

Definition at line 110 of file LinqExtensions.cs.

◆ Median< T, TProperty >()

static TProperty QuantConnect.Util.LinqExtensions.Median< T, TProperty >	(	this IEnumerable< T >	collection,
		Func< T, TProperty >	selector
	)

static

Gets the median value in the collection

Template Parameters

T	The item type in the collection
TProperty	The type of the value selected

Parameters

collection	The collection of items to search
selector	Function used to select a value from collection items

Returns: The median value, throws InvalidOperationException if no items are present

Definition at line 124 of file LinqExtensions.cs.

◆ BinarySearch< TItem, TSearch >()

static int QuantConnect.Util.LinqExtensions.BinarySearch< TItem, TSearch >	(	this IList< TItem >	list,
		TSearch	value,
		Func< TSearch, TItem, int >	comparer
	)

static

Performs a binary search on the specified collection.

Template Parameters

TItem	The type of the item.
TSearch	The type of the searched item.

Parameters

list	The list to be searched.
value	The value to search for.
comparer	The comparer that is used to compare the value with the list items.

Returns: The index of the item if found, otherwise the bitwise complement where the value should be per MSDN specs

Definition at line 138 of file LinqExtensions.cs.

◆ BinarySearch< TItem >() [1/2]

static int QuantConnect.Util.LinqExtensions.BinarySearch< TItem >	(	this IList< TItem >	list,
		TItem	value
	)

static

Performs a binary search on the specified collection.

Template Parameters

TItem The type of the item.

Parameters

list	The list to be searched.
value	The value to search for.

Returns: The index of the item if found, otherwise the bitwise complement where the value should be per MSDN specs

Definition at line 180 of file LinqExtensions.cs.

◆ BinarySearch< TItem >() [2/2]

static int QuantConnect.Util.LinqExtensions.BinarySearch< TItem >	(	this IList< TItem >	list,
		TItem	value,
		IComparer< TItem >	comparer
	)

static

Performs a binary search on the specified collection.

Template Parameters

TItem The type of the item.

Parameters

list	The list to be searched.
value	The value to search for.
comparer	The comparer that is used to compare the value with the list items.

Returns: The index of the item if found, otherwise the bitwise complement where the value should be per MSDN specs

Definition at line 193 of file LinqExtensions.cs.

◆ Memoize< T >()

static IEnumerable<T> QuantConnect.Util.LinqExtensions.Memoize< T > ( this IEnumerable< T > enumerable )

static

Wraps the specified enumerable such that it will only be enumerated once

Template Parameters

T	The enumerable's element type

Parameters

enumerable The source enumerable to be wrapped

Returns: A new enumerable that can be enumerated multiple times without re-enumerating the source enumerable

Definition at line 204 of file LinqExtensions.cs.

◆ Range< T >()

static IEnumerable<T> QuantConnect.Util.LinqExtensions.Range< T >	(	T	start,
		T	end,
		Func< T, T >	incrementer,
		bool	includeEndPoint = `false`
	)

static

Produces the an enumerable of the range of values between start and end using the specified incrementing function

Template Parameters

T	The enumerable item type

Parameters

start	The start of the range
end	The end of the range, non-inclusive by default
incrementer	The incrementing function, with argument of the current item
includeEndPoint	True to emit the end point, false otherwise

Returns: An enumerable of the range of items between start and end

Type Constraints

T

:

IComparable

Definition at line 220 of file LinqExtensions.cs.

◆ GroupAdjacentBy< T >()

static IEnumerable<IEnumerable<T> > QuantConnect.Util.LinqExtensions.GroupAdjacentBy< T >	(	this IEnumerable< T >	enumerable,
		Func< T, T, bool >	grouper
	)

static

Groups adjacent elements of the enumerale using the specified grouper function

Template Parameters

T	The enumerable item type

Parameters

enumerable	The source enumerable to be grouped
grouper	A function that accepts the previous value and the next value and returns true if the next value belongs in the same group as the previous value, otherwise returns false

Returns: A new enumerable of the groups defined by grouper. These groups don't have a key and are only grouped by being emitted separately from this enumerable

Definition at line 251 of file LinqExtensions.cs.

◆ AreDifferent< T >()

static bool QuantConnect.Util.LinqExtensions.AreDifferent< T >	(	this ISet< T >	left,
		ISet< T >	right
	)

static

Determines if there are any differences between the left and right collections. This method uses sets to improve performance and also uses lazy evaluation so if a difference is found, true is immediately returned and evaluation is halted.

Template Parameters

T	The item type

Parameters

left	The left set
right	The right set

Returns: True if there are any differences between the two sets, false otherwise

Definition at line 286 of file LinqExtensions.cs.

◆ AsEnumerable< T >()

static IEnumerable<T> QuantConnect.Util.LinqExtensions.AsEnumerable< T > ( this IEnumerator< T > enumerator )

static

Converts an IEnumerator<T> to an IEnumerable<T>

Template Parameters

T	Collection element type

Parameters

enumerator The enumerator to convert to an enumerable

Returns: An enumerable wrapping the specified enumerator

Definition at line 301 of file LinqExtensions.cs.

◆ GetValueOrDefault< K, V >()

static V QuantConnect.Util.LinqExtensions.GetValueOrDefault< K, V >	(	this IDictionary< K, V >	dictionary,
		K	key,
		V	defaultValue = `default(V)`
	)

static

Gets the value associated with the specified key or provided default value if key is not found.

Template Parameters

K	The key type
V	The value type

Parameters

dictionary	The dictionary instance
key	Lookup key
defaultValue	Default value

Returns: Value associated with the specified key or default value

Definition at line 321 of file LinqExtensions.cs.

◆ DoForEach< T >()

static void QuantConnect.Util.LinqExtensions.DoForEach< T >	(	this IEnumerable< T >	source,
		Action< T >	action
	)

static

Performs an action for each element in collection source

Template Parameters

T

Parameters

source	Collection source
action	An action to perform

Definition at line 333 of file LinqExtensions.cs.

The documentation for this class was generated from the following file:

Common/Util/LinqExtensions.cs

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ ToReadOnlyDictionary< K, V >()

◆ ToHashSet< T, TResult >()

◆ ToList< T, TResult >()

◆ ToArray< T, TResult >()

◆ ToImmutableArray< T, TResult >()

◆ IsNullOrEmpty< T >()

◆ Median< T >()

◆ Median< T, TProperty >()

◆ BinarySearch< TItem, TSearch >()

◆ BinarySearch< TItem >() [1/2]

◆ BinarySearch< TItem >() [2/2]

◆ Memoize< T >()

◆ Range< T >()

◆ GroupAdjacentBy< T >()

◆ AreDifferent< T >()

◆ AsEnumerable< T >()

◆ GetValueOrDefault< K, V >()

◆ DoForEach< T >()