The `@experimental` experiment

Things are still mostly pretty quiet on the Dotty-repo front, with folks focused on readying Scala 3 for release. But there are some fun bits still happening in the background.

One of those is this PR from a couple of days ago, which is getting some active discussion. It would add a new @experimental annotation, basically lifting the notion of “experimental” features up into language-space, rather than being hardcoded in the compiler.

IMO this is a great idea, at least in principle — it extends Scala’s usual “no magic” ethos into yet another aspect of the language. They’re still discussing whether to make it available to userland code for the use of library authors; personally, I hope they do so, since it’s a generally-useful concept.

Regardless, at this late stage I think it’s very unlikely that this will show up in 3.0 — it isn’t strictly necessary, and enhancements need to be looked at with a pretty acid eye right now. But hopefully it will show up in a near-future release. Check it out…