On: Why GitHub used Haskell for Semantic

[_bxg1]

Does it have trap-doors for optimization like Clojure's transient data structures?

[weavie → _bxg1]

There is unsafePerformIO, but it's generally considered a really bad idea unless you really know what you are doing, and even then it is probably a bad idea. It is useful for debugging though and putting trace statements in.