Were it Haskell related, well, could be up on HN for days ;-)
Maybe Dotty will bring some excitement back to Scala, these days it's just bashed upon endlessly, which is unfortunate. Personally I love Scala, warts and all, it's a wonderful language that often draws criticism without admitting any of its myriad strengths.
Inferring loose immutability constraints on a function would be interesting. You could implement it in the compiler, perhaps something like an annotation on a method that declares all inputs must consist of only final/immutable values, enforced all the way down the chain.
This is more of a JVM gripe, but as long as we're talking about Go, I'd love to see actual VM-level coroutine support. It'd make async code in Scala a lot easier to both author and debug.
Actually, thinking about it, why not just make it illegal to modify arguments, full stop? It's perhaps the worst software practice I can think of.
I think Oracle is going to wait a long time until they add that to Java, and it's not going into the JVM before it's going into Java, unfortunately. Well, there is a limited number of instructions in the JVM, so using them on things that are unproven might be a very bad idea.
I guess for Java devs new to Scala that might seem a viable approach at first...so yes, maybe forcing the user to be explicit in the same way that the `var` keyword is required to stray into mutable territory would be a good thing -- certainly wouldn't bother those that use immutable constructs 99% of the time.
Plus, HN definitely has its fair share of "the only thing written in Haskell is Haskell" commenters.
I'm not anti-Scala—I develop in it every day and think it's a great language. But bashing a strawman like that isn't going to win anyone over.
re: language flamewars, interesting, perhaps you've noticed some of the FP heavies laying into Scala here on HN, Reddit and Twitter. I'd say the flaming by an overwhelming majority is coming from the other side of the fence.
These days, it's best just to read all of the comments, including any that have been grayed out. A lot of the time they're perfectly legitimate. It's just unfortunate that they're harder to read.
I agree, sometimes heavily downvoted comments reflect the truth of things more than those comments that are upvoted via, say, sycophantic pandering.
A nice HN addition would be to toggle comment color; that way one could view greyed out comments in isolation relative to upvoted comments and vice-versa.