[cies]

https://dhall-lang.org/

Cool indeed. I wonder how you can supply it with types from the program that consumes the config.

My Gradle config is in Kotlin these days. Kotlin, besides being a full blown prog lang, has nice features for config specs (map/list literals, typed, eDSL syntax). Though it is an enormous dependency (way to big for a project that just needs a config file format).

[piaste]

The bigger Dhall type libraries are usually generated from OpenAPI specs - there is a core package that consumes them.

If your language has an OpenAPI library, you can create a hello-world web app that exposes your configuration object as an HTTP endpoint, and generate Dhall types from that.