These days, using a statically typed language for configuration makes a lot of sense. You get stronger typing and with type inference not necessarily a lot more verbosity.
Kotlin and kotlin script seems to work reasonably well for Gradle. Gradle unfortunately has a bit of groovy legacy, which makes it a bit convoluted for some things. But Kotlin DSLs are quite nice for configuring things and it removes a lot of ambiguity when your editor can tell you a property doesn't exist or that a list instead of a string is expected. or help you autocomplete things that are allowed.
Basically the ultimate in configuration languages is something that has a minimal syntax but provides enough structure for tooling to help you validate things, provide autocomplete and other help, etc. There are now several languages emerging that have both static typing and some level of support for internal DSLs. Ruby sort of pioneered a lot of configuration DSLs back in the day but since it was dynamically typed, tool support for these DSLs was a lot harder. With languages like Kotlin, Swift, C#, Rust, etc. you get enough expressiveness that you can do similar internal DSLs but with the advantage of more robust tooling support.
Agreed, but the best combination is type-safe and non-turing complete, ideally with restricted effects. [Dhall](https://github.com/dhall-lang/dhall-lang) gets this so right that I'm increasingly shocked that people never seem to have heard of it.
This is a good example of a structured approach, with the caveat that there are multiple phases.
With gradle, there's three big phases: initialization, configuration, then execution. (See https://docs.gradle.org/current/userguide/build_lifecycle.ht...). I'd think you'd need to do something similar with any structured configuration DSL - have distinct phases where you may "init, plan, apply", etc.
This, it's a pretty complex problem to have. But that complexity may be worth it as part of a "developer productivity engineering" effort, where you're really looking to use data to minimize the time between a configuration change, and the time it's applied in a runtime environment. Doing that is a hard problem.
The only thing I don't like with Kotlin is the lack of a decent syntax for list and map literals. Unfortunately it seems to have resolved in a dead end as far as implementation into the language goes. It's still a nice language but quite awkward and ugly in the context of expressing a lot of literal data.
Kotlin and kotlin script seems to work reasonably well for Gradle. Gradle unfortunately has a bit of groovy legacy, which makes it a bit convoluted for some things. But Kotlin DSLs are quite nice for configuring things and it removes a lot of ambiguity when your editor can tell you a property doesn't exist or that a list instead of a string is expected. or help you autocomplete things that are allowed.
Basically the ultimate in configuration languages is something that has a minimal syntax but provides enough structure for tooling to help you validate things, provide autocomplete and other help, etc. There are now several languages emerging that have both static typing and some level of support for internal DSLs. Ruby sort of pioneered a lot of configuration DSLs back in the day but since it was dynamically typed, tool support for these DSLs was a lot harder. With languages like Kotlin, Swift, C#, Rust, etc. you get enough expressiveness that you can do similar internal DSLs but with the advantage of more robust tooling support.