Recursion and merging semantics are also necessary. I use Nix and Jsonnet a lot, but Nix is much more expressive for complex structures, but the tooling being

Recursion and merging semantics are also necessary. I use Nix and Jsonnet a lot, but Nix is much more expressive for complex structures, but the tooling being tightly coupled with the package manage make it impossible to adopt for common use cases.