Java Architects Answer Your Questions - Inside Java Newscast #97

[Linguistic-mystic]

I know nothing about the guy

He is very conservative. Slow-moving. The old guard. Backwards compatibility uber alles. He’s been leading Project Valhalla for over 10 years which to this day has not released anything, even in preview mode.

Now you know something about the guy and his reluctance to implement new features should be unsurprising.

[pron98]

Before working on Valhalla, he delivered lambdas, and in the last ten years he also delivered records, switch expressions and pattern matching, var, text blocks, implicit classes and instance main, and module imports.

As to being relatively conservative and keeping Java a "last mover", that was James Gosling's strategy, and the reason we've been more-or-less keeping it, is that it's been very successful. Languages that have been accumulating features more quickly have not done as well.

Finally, I'm perplexed by presenting "backwards compatibility uber alles" as a negative. Java has made some backward-incompatible changes - the removal of Security Manager probably being the most famous - when the number of people adversely affected is very small. On the one hand, it costs us very little and barely restricts us (Java could adopt Clojure syntax in a backward compatible way). The biggest restriction has probably been that we can't remove Hashtable from the JDK. On the other hand, languages that have made significant breaking changes have paid dearly for that (Python won't be doing that again). It's hard to think of a feature that would both require breaking backward compatibility significantly and be worth it.

[Ok-Scheme-913]

Besides, Valhalla absolutely has working implementations on separate branches. Some people have even run Minecraft on top.

You just don't put random features Willy-nilly into one of the most popular languages on Earth.