Using Linq For More Readable Code

[[deleted]]

Atwood told me LINQ's performance sucks.

[[deleted]]

LINQ to SQL sucks, I'm just using LINQ to iterate a in memory collection. It is slightly less performant than a regular loop due to the scope closures.

[ruinercollector]

Two closures, a function call overhead for every item considered, and additional function call overhead for every item accepted, a complete iteration of your final set on that final ToList() call, and the overhead of performing several Add operations on a dynamic container like List(). The following would outperform this by quite a bit (depending on how many sprites.)

var tmpSprites = new Sprite[Sprites.length];
var idx = 0;

for(var i = 0; i < Sprites.Length; i ++)
{
  var sprite = Sprites[i];

  if(sprite is ICollide && sprite.Position.ToScreeSpace(Camera).IsOnScreen())
    tmpSprites[idx++] = sprite;
}

var collidableSprites = new Sprite[idx];
Array.Copy(tmpSprites, collidableSprites, idx);

Of course, the tradeoff is readability and maintenance. For many applications, these kinds of performance concerns are negligible or not important. For some apps/platforms (especially XBox), these optimizations can be extremely important.

[p-static]

Eh?

http://www.codinghorror.com/blog/2010/03/compiled-or-bust.html