[noelwelsh]

Good article. Not much to add to it, other than I think more people should look at modal type systems like found in Scala 3 and OxCaml. If you want safe arena allocation they are a lot more ergonomic than Rust's approach.

[debugnik]

I'm familiar with OxCaml, but in what sense does Scala have modalities?

[noelwelsh]

Scala's capture checking [1] is a modal type system.

[1]: https://docs.scala-lang.org/scala3/reference/experimental/cc...