For those of you, who don't know, Who Tim Sweeney is?<p>Tim Sweeney is the founder of Epic Games and the person behind very famous Unreal game engines. John Carmack,Tim Sweeney have been some of my heroes from gaming world.<p><a href="http://en.wikipedia.org/wiki/Tim_Sweeney_%28game_developer%29" rel="nofollow">http://en.wikipedia.org/wiki/Tim_Sweeney_%28game_developer%2...</a>
<i>Purely Functional is the right default<p>Imperative constructs are vital features
that must be exposed through explicit
effects-typing constructs</i><p>This is precisely the argument Haskellers make every time someone complains about algorithms that are difficult to formulate functionally.
There's some further discussion of this over at LtU (<a href="http://lambda-the-ultimate.org/node/1277" rel="nofollow">http://lambda-the-ultimate.org/node/1277</a>)
This might be old, but it very excellently done. One thing I like about it is that the assertions an conclusions are backed up by 1) real-world experience 2) deep understanding of programming language issues.