Given an enumeration such as MPMusicShuffleMode, which has 4 cases, what's the best way *cycle* through them?

[tera]

@Hacksaw

Yeah, the ergonomic here are key to me. What I really want is a universal way to find out the cases, which is also available to the LSP server, so that I can easily construct a switch if I need to control the ordering, or do it automatically if I don't care.

So you are doing this en masse not just for one or three types? What exactly is your app doing?

Ideally we could add CaseIterable on Obj-C imported types, but there must be a (good?) reason it is currently impossible.

@Hacksaw

Even better would be for the result to be a compiled constant or a linked list, so the O(n) could be short circuited somehow.

I'm rather curious what you app is doing. If O(n) behaviour is a potential concern, that means either N is big, or next is called frequently, (or both); what is it you are using "cycling through enums" for?

One possible solution - during the first call next may iterate through all items in O(n) time and construct "array of next elements", so the subsequent next calls work in O(1) time.

@Hacksaw

I'm curious about the realtime issue you don't mention.

See this thread.