Method WindowLeft

WindowLeft<TSource, TResult>(IEnumerable<TSource>, int, ReadOnlySpanFunc<TSource, TResult>)

Creates a right-aligned sliding window over the source sequence of a given size.

Declaration

public static IEnumerable<TResult> WindowLeft<TSource, TResult>(this IEnumerable<TSource> source, int size, SuperEnumerable.ReadOnlySpanFunc<TSource, TResult> selector)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The sequence over which to create the sliding window.
int	size	Size of the sliding window.
SuperEnumerable.ReadOnlySpanFunc<TSource, TResult>	selector	A transform function to apply to each window.

Returns

Type	Description
IEnumerable<TResult>	A sequence representing each sliding window.

Type Parameters

Name	Description
TSource	The type of the elements of source.
TResult	The type of the value return by selector.

Remarks

A window can contain fewer elements than size, especially as it slides over the start of the sequence.

In this overload of WindowLeft, a single array of length size is allocated as a buffer for all subsequences.

This operator uses deferred execution and streams its results.

Exceptions

Type	Condition
ArgumentNullException	source or selector is null.
ArgumentOutOfRangeException	size is below 1.

WindowLeft<TSource, TResult>(IEnumerable<TSource>, TSource[], ReadOnlySpanFunc<TSource, TResult>)

Creates a right-aligned sliding window over the source sequence of a given size.

Declaration

public static IEnumerable<TResult> WindowLeft<TSource, TResult>(this IEnumerable<TSource> source, TSource[] array, SuperEnumerable.ReadOnlySpanFunc<TSource, TResult> selector)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The sequence over which to create the sliding window.
TSource[]	array	An array to use as a buffer for each subsequence.
SuperEnumerable.ReadOnlySpanFunc<TSource, TResult>	selector	A transform function to apply to each window.

Returns

Type	Description
IEnumerable<TResult>	A sequence representing each sliding window.

Type Parameters

Name	Description
TSource	The type of the elements of source.
TResult	The type of the value return by selector.

Remarks

A window can contain fewer elements than array.Length, especially as it slides over the start of the sequence.

In this overload of WindowLeft, array is used as a common buffer for all subsequences.

This operator uses deferred execution and streams its results.

Exceptions

Type	Condition
ArgumentNullException	source, selector, or array is null.

WindowLeft<TSource, TResult>(IEnumerable<TSource>, TSource[], int, ReadOnlySpanFunc<TSource, TResult>)

Creates a right-aligned sliding window over the source sequence of a given size.

Declaration

public static IEnumerable<TResult> WindowLeft<TSource, TResult>(this IEnumerable<TSource> source, TSource[] array, int size, SuperEnumerable.ReadOnlySpanFunc<TSource, TResult> selector)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The sequence over which to create the sliding window.
TSource[]	array	An array to use as a buffer for each subsequence.
int	size	Size of the sliding window.
SuperEnumerable.ReadOnlySpanFunc<TSource, TResult>	selector	A transform function to apply to each window.

Returns

Type	Description
IEnumerable<TResult>	A sequence representing each sliding window.

Type Parameters

Name	Description
TSource	The type of the elements of source.
TResult	The type of the value return by selector.

Remarks

A window can contain fewer elements than size, especially as it slides over the start of the sequence.

In this overload of WindowLeft, array is used as a common buffer for all subsequences.
This overload is provided to ease usage of common buffers, such as those rented from ArrayPool<T>, which may return an array larger than requested.

This operator uses deferred execution and streams its results.

Exceptions

Type	Condition
ArgumentNullException	source, selector, or array is null.
ArgumentOutOfRangeException	size is below 1 or above array.Length.

WindowLeft<TSource>(IEnumerable<TSource>, int)

Creates a left-aligned sliding window of a given size over the source sequence.

Declaration

public static IEnumerable<IList<TSource>> WindowLeft<TSource>(this IEnumerable<TSource> source, int size)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The sequence over which to create the sliding window.
int	size	Size of the sliding window.

Returns

Type	Description
IEnumerable<IList<TSource>>	A sequence representing each sliding window.

Type Parameters

Name	Description
TSource	The type of the elements of source.

Remarks

A window can contain fewer elements than size, especially as it slides over the end of the sequence.

This operator uses deferred execution and streams its results.

Examples

The following code example demonstrates how to generate a sliding window over a sequence using WindowLeft.

var sequence = Enumerable.Range(1, 10);

// Get a sliding window over the sequence
var result = sequence.WindowLeft(3);

Console.WriteLine(
    "[" + Environment.NewLine + 
    string.Join(
        ", " + Environment.NewLine,
        result.Select(c => "   [" + string.Join(", ", c) + "]")) +
    Environment.NewLine + "]");

// This code produces the following output:
// [
//    [1, 2, 3],
//    [2, 3, 4],
//    [3, 4, 5],
//    [4, 5, 6],
//    [5, 6, 7],
//    [6, 7, 8],
//    [7, 8, 9],
//    [8, 9, 10],
//    [9, 10],
//    [10]
// ]

Exceptions

Type	Condition
ArgumentNullException	source is null.
ArgumentOutOfRangeException	size is below 1.