At the end of that spectrum (moving away from values and towards types) are languages like Coq, where you have only types, no values, and it's the compiler that

At the end of that spectrum (moving away from values and towards types) are languages like Coq, where you have only types, no values, and it's the compiler that derives the implementation/values from the types you define. Like Haskell Servant[1], where you define your API as a type, and then you can derive functions from that type to query the API, because the type itself contains all the information necessary. Pretty fascinating stuff. [1] http://haskell-servant.readthedocs.io/en/stable/tutorial/ApiType.html http://haskell-servant.readthedocs.io/en/stable/tutorial/Api...