Douglas Hill •

TIL about the ContactProvider framework on iOS (not Mac). Sounds like a way to build an end-to-end encrypted replacement for iCloud/CardDAV contacts sync if you can get your head around the difference between ContactItemEnumerating and ContactItemEnumerator.

protocol ContactItemEnumerating: A protocol to provide enumerators for collections of contact items. protocol ContactItemEnumerator: A protocol to provide enumerations of all contact items and changed contact items.