[roenxi]

Clojure is marketed as a very fast language (bunch of clever optimisation gets done because data structures are immutable). If the gains were from switching to Java they'd probably have said so less ambiguously.

Surely what they mean is they've rewritten it to be faster, and switched to Java at the same time because they want to open up the contributor pool.

[0815test]

BTW, if anyone's looking for another language that stresses immutability on the JVM, you might want to check out Frege, a Haskell-like language with some "tweaks" that make it work well in that environment. https://github.com/Frege/frege

And as a sibling comment mentions, the announcement does clearly state that a rather extensive rewrite was done, including switching to a new architecture, with likely performance improvements coming from that - it's nowhere close to a pure Java vs. Clojure comparison.

[fiddlerwoaroof]

My impression is that Eta is a better choice, if only because it is compatible with a wider variety of Haskell libraries.

https://eta-lang.org/

[0815test]

Eta is a better choice, if you care about Haskell compatibility in the strictest sense. Frege doesn't really pursue this, but the flip side is that it optimizes for working as smoothly as possible with the JVM ecosystem.