This looks great, but the edit feature is not actually something you can't have in IRB. Both my own utility_belt gem from 2007 and another person's sketches gem from 2009 enabled the same functionality.

I think Pry is great, I wrote a little console with it recently for a simple back-end app, and the edit feature looks like your most advanced option for this kind of thing. But for the sake of accuracy, it's not actually 100% brand new functionality. A lot of people have been doing that in IRB for a long time.