using System;

using System.Collections.Generic;

using System.Text.RegularExpressions;

​

public class Program

{

    private static string[] Tokenize(string expression)

    {

        List<string> result = new List<string>();

        List<string> tokens = new List<string>();

​

        tokens.Add("(^\\()");// matches opening bracket

        tokens.Add("(^([\\d.\\d]+))"); // matches floating point numbers

        tokens.Add("(^[&|<=>!]+)"); // matches operators and other special characters

        tokens.Add("(^[\\w]+)"); // matches words and integers

        tokens.Add("(^[,])"); // matches ,

        tokens.Add("(^[\\)])"); // matches closing bracket

        tokens.Add("(?!\\+)(?:\"((?:\\\\\"|[^\"])*)\"?)"); // matches quoted string

​

        while (0 != expression.Length)

        {

            bool foundMatch = false;

​

            foreach (string token in tokens)

            {

                Match match = Regex.Match(expression, token);

                if (false == match.Success)

                {

                    continue;

                }

​

                result.Add(match.Groups[1].Value);

                expression = Regex.Replace(expression, token, "");

                foundMatch = true;

​

                expression = Regex.Replace(expression, @"\s*\+\s*", "");    // Remove concatenation

                break;

            }

​

            if (false == foundMatch)

            {

                break;

            }

        }

​

        return result.ToArray();

    }

    public static void Main()

    {

        string[]    res = Tokenize("H5 + \" is smaller than (\\\") \" + 10");

        foreach( string s in res )

        {

            Console.WriteLine(">" + s + "<");

        }

    }

}