An interesting candidate in the other end of the spectrum is Dhall, https://dhall-lang.org https://dhall-lang.org. If I was working in one of the languages wi

An interesting candidate in the other end of the spectrum is Dhall, https://dhall-lang.org https://dhall-lang.org. If I was working in one of the languages with current implementations I would no doubt try it out. Edit: I will also add that dhall will export to YAML/JSON etc, however I'm not a fan on intermediary config file processing.