Immutability code for informatorbloggen

program.cs

public static void Main(string[] args)
{
  string[] input = {"Ramy", "Gregory", "Willstrop", 
                         "Matthew", "El Shorbagy", "Drakenberg", "Hult", "Friberg"};
    
  var players = new ImmutableList<SquashPlayer>();
  var rnd = new Random();

	var writer = new Thread( () => {
        int i = 1;
        foreach(string name in input)
        {
          var player = new SquashPlayer(name, i++);
          players = players.Add(player); //tilldelning är en atomär operation
          Thread.Sleep(rnd.Next(1000));
	}
	});
	
   var reader = new Thread( () => {
        for(int i = 0; i < 1000000; i++)
        {
          int rankingSum = 0;
	  var playersRef = players; //läser en ögonblicksbild av en omutbar lista
	  int count = players.Count;
	  foreach(var player in playersRef) rankingSum += player.Ranking;
	  Debug.Assert((1 + count)/2.0*count == rankingSum);
        }
     });
	
	writer.Start();
	reader.Start();
	writer.Join();
	reader.Join();
}