[aidenn0]

Sorry, my reply, like throwaway's missed the main point of your original comment of "why not a GP programming language"

A configuration file is uniquely suited to a pure and lazy language.

Pure, because the all the advantages of a pure language remain, while none of the downsides; the result of evaluating the function is your configuration data. You don't need to do arbitrary I/O and ordering for generating configuration files.

Lazy because configuration files are naturally declarative, but you don't want to evaluate tons of things you have declared but then never used.