Interpreters are allowed, native code execution (including JIT) is not.
Additionally, if you submit an application with an interpreter to the App Store, you will get declined if you make it easy for your users to download arbitrary scripts / code and execute it in your interpreter.
"3.3.2 An Application may not download or install executable code. Interpreted code may only be used in an Application if all scripts, code and interpreters are packaged in the Application and not downloaded. The only exception to the foregoing is scripts and code downloaded and run by Apple’s built-in WebKit framework."
Exporting, however is ok.
Additionally, it's not expressed explicitly but user-created scripts are also allowed.
We were forced to remove email sharing of projects in Codea in 2011.
It seems like more and more apps are being allowed to include downloadable scripts. I wonder if there is some unwritten change of policy for coding apps. Interesting to see that Editorial includes this (and it looks like an amazing app).
I've been using vim on iOS through Prompt[1] for a while and it's been perfectly usable without an external keyboard (I'm using an iPhone anyway). If your device is jailbroken you can use SSH to localhost and hack away. Note: I have not yet tried tmux over Prompt so I can't say whether it's a good idea or not. Nor have I tried emacs.
Is it possible to detect when a bluetooth keyboard is not attached? Seems like it would make sense to do so and provide an onscreen panel with :, ESC, and maybe some user-settable keys.
http://www.macstories.net/stories/editorial-for-ipad-review/
http://www.macdrifter.com/2013/08/editorial-for-ipad-a-landm...