fully-homomorphic-encryption VS libaco

Secure computing. This includes Fully Homomorphic Encryption AKA FHE, of which there is a language/compiler which just got released and Google's older FHE compiler. FHE is probably more "compiler" than "type system", e.g. Google's compiler works on C++. Also Security Type Systems which include Oblivious data structures and Oblivious ADTs.

I don't have any advice for you, but I do work on homomorphic encryption at Google and we have an FHE compiler project [1] (though it is likely going to change a lot in the coming year). I happen to have a math PhD, so the transition to this field was not a huge stretch, but before that I worked in supply chain optimization for data centers, and just decided this was too exciting to pass up.

[1]: https://github.com/google/fully-homomorphic-encryption/issue...

+1, and some compilers already exist to do that for you. See, e.g., Google's compiler (which I work on). https://github.com/google/fully-homomorphic-encryption

Once the tools are written, you should be able to take a program written in some language foo and transpile it to a FHE version of foo. See Google's C++ to FHE-C++ transpiler. Thus, you can test/debug your application without FHE before transpiling to something that is FHE.

Coroutines, async/await and general multicore support in the type system. Most languages by now either have some variant of async / await (JavaScript, Kotlin, Swift, Rust) or super-lightweight threads (Go, Elixir, Java via Project Loom), or they just have Monads which supersede coroutines entirely (Haskell, Scala). It's at the point where some say a language isn't suitable for production if it doesn't have good multicore support (also see Rust speeding through getting async/await even though they already have Send + Sync). Even Python and C++ have coroutines now, and of course there is a coroutine library for C which uses macros and low-level magic.