I've seen (and still use to a small extent) a templating language like that. The real exciting thing is the documentation! There is none, so you scrape through

I've seen (and still use to a small extent) a templating language like that. The real exciting thing is the documentation! There is none, so you scrape through the existing codebase to find one that is doing the sort of thing you want to do and copy it Doesn't help that the interpreter for it was not written in a language we use and it is stuck on a particular version due to some bytecode libraries we don't have the source to