> It's not an accident that the talk/article is about Clojure
On the other hand, I'm surprised that the optimizations in question don't happen automatically for Clojure programs. Surely the underlying JVM is capable of constant propagation and folding? Maybe it's the let-from-let optimization that actually gets the 10% speedup.
Oh, you do say it in the article: "However, for the maximum reach, we want our game to run in the web browsers." I missed that, thanks.
But even so, JavaScript compilers aren't stupid. No need to do this for me of course, but if you got around to measuring the performance impact of the two optimizations separately, I'd be interested in that. (And the ClojureScript developers might be interested too.)
On the other hand, I'm surprised that the optimizations in question don't happen automatically for Clojure programs. Surely the underlying JVM is capable of constant propagation and folding? Maybe it's the let-from-let optimization that actually gets the 10% speedup.