[Cyberdog]

In practice, nobody is seriously writing Swift code (or any other code) on iOS devices. My meaning was I don't understand why this is an iOS app instead of a Mac app or even a web one (like IBM's Swift sandbox[1]).

That being said, I'm kind of impressed someone managed to get an app on the App Store that can do this. I know that Apple loosened its restrictions on code execution on iOS a while back, but as far as I am aware there's no way to compile Swift on ARM… did they write their own compiler/runtime or something?

1: https://developer.ibm.com/swift/2015/12/03/introducing-the-i...

[jonsen]

It is a learning tool. Handy to have on a mobile device. Learn while commuting for example.

[kazazes]

The lessons and exercises are limited in scope enough that they are entirely static. The work the app needs to do is limited to parsing, stylizing, checking (simple) syntax and matching user input to the task, not executing it. The lessons themselves are no more complex than a programming PPT presentation that looks prettier.

[Cyberdog]

All the more reason iOS is a bizarre platform for this, then.

[nilliams]

What's bizarre about it? Apple developers tend to own other Apple devices and are likely to want to learn Swift on the go.