Many IDEs are very mature on desktop such as Xcode, visual studio and eclipse(I am skeptical about eclipse). In the mobile world , it is still in initial stage. Some argue there is no point of coding on small screen mobile devices ?
There are lot of constraints but not limited to IDE
* Screen size is small
* No physical keyboard
* Slow processor
* Short Battery life
* Small storage
I agree there are limitations, but should these be the reasons of not having coding on mobile device ?
Sreen size is a problem but not fatal. Virtual keyword is even more difficult to solve. Some tried to reinvent virtual keyword without different layouts and typing prediction.
No matter how it is improved we can only use two fingers on virtual keyboard instead of ten fingers on full size physical keyboard.
Another issue is that there are too many lines of codes, if you try to view java source on iPad , it may not be enough for a function. But it could be an entire program in case of lisp.