The funny thing about managed code is that sometimes people forget that just because we offer an easy/convenient way to do things if you're doing a quick RAD application doesn't mean that the RAD way is in fact the right way.  In fact, the good old fashioned way is very likely still available and may be an excellent choice.   So that brings us to Performance Quiz #3.

The question:  Characterize the difference in space and speed between RadParser and ClassicParser, consider the given test input to be typical.

I'll post an analysis in a few days.  Don't peek at the feedback until you're done with your own work :)

--------- radparser.cs ---------------

using System;
using System.IO;

class RadParser
{
    static void Main(String[] args)
    {
        StreamReader stream = new StreamReader(args[0]);

        String line;
        Char[] delims = { ' ', '\t' };
        int sum = 0;

        while ((line = stream.ReadLine()) != null)
        {
            String[] fields = line.Split(delims);

            foreach (String field in fields)
            {
                sum += Int32.Parse(field);
            }
        }

        Console.WriteLine("The total of the ints is: {0,8:n0}", sum);
    }
}

---- testfile.txt (2500 lines of this)
234 2348 -7295 27 52932 -2352 2352 252532 1 34 452 52 345 2 245 4525


--------- classicparser.cs ---------------

using System;
using System.IO;

class ClassicParser
{
    static void Main(String[] args)
    {
        FileStream fs = new FileStream(args[0], FileMode.Open, FileAccess.Read);
        Byte[] bytes = new Byte[4096];

        int sum = 0;
        int tmp = 0;
        bool negative = false;
        bool digits = false;

        for (;;)
        {
            int count = fs.Read(bytes, 0, bytes.Length);

            if (count <= 0)
            {
                if (negative)
                    sum -= tmp;
                else
                    sum += tmp;
                break;
            }

            for (int i = 0; i < count; i++)
            {
                switch ((char)bytes[i])
                {

                case ' ': case '\t': case '\r': case '\n':
                    if (negative)
                        sum -= tmp;
                    else
                        sum += tmp;

                    negative = false;
                    digits = false;
                    tmp = 0;
                    break;

                case '-':
                    if (negative)
                        throw new FormatException("two negatives");

                    if (digits)
                        throw new FormatException("negative after digits");

                    negative = true;
                    break;

                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                    digits = true;
                    tmp = tmp*10 + bytes[i] - (Byte)'0';
                    break;

                default:
                    throw new FormatException("invalid character");
                }
            }
        }

        Console.WriteLine("The total of the ints is: {0,8:n0}", sum);
    }
}