That sounds to me like the definition of living hell. Writing prose on a touchscreen is bad already, I can't imagine how bad it must be to write actual code on one. It's not an iPad(OS) problem, it's a form factor/peripheral problem.
I've found prose is much more painful (by orders of magnitude really) than code (provided the keyboard has symbol/modifier keys and works well with your editor.) that's why I thought it wouldn't work.
