I think Dhall is good at pushing forward some ideas, but honestly I feel like Skylark (Python but not turing complete) just feels like the right way forward. Being able to specify dynamic functionality in a configuration file, when paired with a good configuration API, really makes stuff straightforward IMO. Gunicorn is the best example of this.
We have all of these tools that try to propose declarative configuration, then run into the fact that people really do want dynamic systems with some abstraction capabilities, and then have to overlay that into their systems.
I feel increasing alone in this position but I absolutely hate those Python-like languages.
They look like Python, and they occasionally act like Python. But occasionally they don't, and the mask of looking like Python obscures those times. Then you never really know which Python facilities you have and which ones you don't.
We have all of these tools that try to propose declarative configuration, then run into the fact that people really do want dynamic systems with some abstraction capabilities, and then have to overlay that into their systems.