Believe it or not, you can alt-tab on an iPad now if you have a keyboard hooked up. https://www.subtraction.com/wp-content/uploads/2015/06/2015-...

And while iOS won't give you a local terminal, remote servers are in reach with a pretty nice SSH client: https://panic.com/prompt/

Text selection on a touchscreen still sucks compared to a mouse, unfortunately.

Still, if an IDE can hit most/all of your needs, I can see iOS working pretty well as a programming environment. Apple's Swift Playgrounds in iOS 10 feels like a first step toward them bringing Xcode over.