I think this suggestion comes from what Unix shells do, albeit I'd say that auto-complete there works rather different from how it usually works in GUI applicat

I think this suggestion comes from what Unix shells do, albeit I'd say that auto-complete there works rather different from how it usually works in GUI applications, browsers, and web applications. It's a model that's useful for some (I personally can't stand it exactly because it amends the input in unpredictable ways, but others get annoyed when a shell doesn't provide it like they're used to), but unless talking on HN it's probably a minority of users that like and prefer it.