* Blocks writing of new files via accidental typos, etc, which the normal open("blah", "a") doesn't.
* Where files don't exist they should ideally be using `(buildpath/"dog").write` instead of open("blah", "a") already.
* It's a bit less cluttered looking if you need several writes to different files in the formula, IMO.
This is the (partially) documented public API for Homebrew.
The main class you should look at is the {Formula} class (and classes linked from there). That's the class that's used to create Homebrew formulae (i.e. package descriptions). Assume anything else you stumble upon is private.