Code completion for MacRuby/PyObjC/RubyMotion

Question

One of Xcode's most powerful features is it's Intellisense completion, which brings up a list of potential candidates as you type the name of a Foundation/Cocoa/UIKit API. I am very interested in MacRuby, PyObjC, or the more recent RubyMotion, however without code completion these tools seem like more trouble than they're worth.

Is there any code completion feature (not necessarily Intellisense) for any of the three technologies above, for any text editor (but preferably for Vim or Xcode)? Bonus points for an IDE solution which allows for building and running the application in a single command (like Xcode's Run button).

It's my understanding that Xcode 4 dropped support for MacRuby/PyObjC, so Intellisense is no longer available. Should I install Xcode 3 alongside Xcode 4 for the code completion? How is everyone else doing it (surely you guys use some form of code completion -- I can't believe anyone can remember all the classes in Foundation/Cocoa/UIKit)?

Answer 1

RubyMotion comes with vi ctag support. Run rake ctags to create them.

Answer 2

FWIW, there is a Code completion package for Sublime Text 2, which can also be installed via the package manager of the Sublime text.

And it seems to work rather well for me.