On 2.1 I cannot agree with you, because if you're using return for clarity, you're circumventing the compiler, which is then unable to do proper inference, not

On 2.1 I cannot agree with you, because if you're using return for clarity, you're circumventing the compiler, which is then unable to do proper inference, not to mention it has gotchas, because as I was saying, most people do not know how return works, and besides, if you need return for clarity, you're doing it wrong and I challenge you to show me a piece of code that is clearer with it. On 2.9/2.14, as somebody that suffered from servers crashing due to enormous load and that had to profile the shit out of everything, I usually find such arguments against persistent data structures to be bullshit, and if you think it matters that much for your problems, you probably picked the wrong language and possibly the wrong platform. And NO, there is no conflict with 3.4. On destructive updates again, there is a fine line between interesting and boring, plus I don't really have time to write a book. But thanks for the feedback, I'll add more details. On 4.1, I really hope you're making a difference between concurrency and parallelism, right? I don't need to back that claim up, just as I don't need to prove that the sky is blue. And as I was telling somebody else, concurrency is not something to take advantage of, but rather something one has to suffer from. On Java's "broken concurrency model", actually I find Java to be quite sane, because at least it has a memory model that works well cross platform and that is generic enough to support all kinds of abstractions built on top, like a sane Future with C#-like async, or light weight threads (Quasar), or extremely efficient queues (LMAX Disruptor), or Erlang-style Actors (Akka), or reactive streams (Rx), or parallel collections (Scala), or STM that works (Scala-STM) or CSP or Agents or what have you. And because there is no silver bullet, all of these abstractions are useful to have in your toolbox. And surely a platform built for a certain abstraction (eg Erlang) will be better than a library, but also find that to be very limiting. Again I challenge you to give me an example of a platform that handles concurrency better than Java. Related to my list, I wasn't the one that posted it BTW, not trying to impose my will on anybody, take from it what you will.