using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		string pattern = @"\\.|\.+|\w+|[^\w\s]";
        string input = @"hello world.";

        foreach (Match m in Regex.Matches(input, pattern, RegexOptions.Singleline))
        {
            Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
        }
	}
}