A beginner's guide to extending Emacs
With that prelude out of the way, let's begin. Inside of emacs you can call up a list of potential completions by using the keyboard shortcut M-. (that’s "hit the meta key along with period", where "meta" is the Alt key for me). This applies in a wide variety of scenarios, like when completing class names or variables. If we want to ask emacs to hand us a list of potential references, then the system we want to hook into is this completions system. (This is the only time I'll assume we know wh