Author here: there is a reason why "programmable configuration language" is a fairly new term. Most of the time, when people want a programmable configuration

Author here: there is a reason why "programmable configuration language" is a fairly new term. Most of the time, when people want a programmable configuration they use whatever language they are already programming in. So, for example, if you are writing a program in Scala you might write the program's configuration in Scala, too. For example, this is how Scala's SBT works: the SBT configuration is written in Scala However, there are some down-sides with writing your configuration within a language like Scala (or any other mainstream language). For example, your program "configuration" can hang, crash, throw exceptions, or destroy your system if it is running with sufficiently elevated privileges. Dhall has none of those problems. Similarly, you can go overboard and use excessive abstraction in other languages, which is inappropriate for a configuration file (which needs to be easy to read and understand). Dhall also avoids this issue by supporting automatic simplification of configuration files to remove abstraction, imports, and indirection (which is made possible by the fact that Dhall is not Turing complete) I'll try to rework the documentation to answer this sort of question better and also incorporate some of the other excellent replies to your question