lists.cs

using System;
using System.Collections.Generic;
using System.Linq;
					
public static class Program
{
	
	public static void Main()
	{		
		Enumerable.Range(0, 9)
			.Squeeze(2)
			.GenerateSuccessivePairs()
			.ToList()
			.ForEach(Console.WriteLine);

		Console.WriteLine();
	}
	
}

public static class ExtensionMethods 
{
	// this method given an enumerable list, will try to truncate the left and right sides equally
	// ie given [4, 5, 6, 7] with a Squeeze of 1, it will return [5, 6], obviously this can not handle
	// large arrays because it scans to the end first
	public static IEnumerable<T> Squeeze<T>(this IEnumerable<T> source, int count) 
	{		
		return source.TruncateLeft(count).TruncateRight(count);
	}
	
	public static IEnumerable<T> TruncateLeft<T>(this IEnumerable<T> source, int count) 
	{
		return source.Skip(count);
	}
	
	public static IEnumerable<T> TruncateRight<T>(this IEnumerable<T> source, int count) 
	{
		var totalToTake = source.Count() - count;
		
		return totalToTake <= 0 
			? Enumerable.Empty<T>()
			: source.Take(totalToTake);
	}
	
	// given an enumerable, it will return a tuple representing the current item 
	// and the one after
	public static IEnumerable<Tuple<T,T>> GenerateSuccessivePairs<T>(this IEnumerable<T> source) 
	{
		return
			source.Zip(source.Skip(1), (a, b) => Tuple.Create(a, b));
	}
	
}