As a favor for a friend, I wrote a mini-"compiler" that translated detailed specs for story game scenes into code. I had never done anything similar (my background is more on the Math/Stats side) but I figured hey, what the hell.

There were only a few types of possible scenes, so my first approach was to create a data structure for each type of scene that had a method converting it to code. However, this broke badly with conditional/branching paths that could potentially have arbitrary levels of nesting.

So my next approach was to create multiple passes using some simple recursive data structures "Parseables" where conditional branches could contain other Parseables (including other conditional branches) as well as multiple passes (Text -> Parseable -> Printable -> Code instead of Text -> Screen -> Code.) This worked quite nicely.

Had I realized this was a compiler, I could have probably read some tutorials and not had to do everything from scratch. This would probably have resulted in better engineering, but been a lot less fun.

My amateurish code, if anyone is curious: https://github.com/Satvik/spec-compiler