Another thing to keep in mind is that with everything being immutable you end up with a pure language. Once that happens, the compiler starts being able to perf

Another thing to keep in mind is that with everything being immutable you end up with a pure language. Once that happens, the compiler starts being able to perform some really nice rewrites of your code really easily. The problem is that this is all or nothing - unless your language is actually pure you can't do this. See this blog post for more <https://donsbot.wordpress.com/2008/06/04/haskell-as-fast-as-c-working-at-a-high-altitude-for-low-level-performance/> https://donsbot.wordpress.com/2008/06/04/haskell-as-fast-as-...