Hi, I’m Ole. I’m a developer from Berlin and co-author of Advanced Swift. Here, I mainly write about Swift and app development on Apple platforms. More about me.

1. Making illegal states unrepresentable

   One of the biggest advantages of a strong type system is that carefully chosen types can make illegal states unrepresentable in your programs. Many Cocoa APIs don’t take full advantage of this because they aren’t optimized for Swift. More >

   March 26, 2018

2. How to make a copy of a Core Data SQLite database

   Making a copy of a SQLite database file while it is being used by Core Data is not safe, and the official Core Data API to do this isn’t easy to use, either. More >

   March 23, 2018

3. A helper for working with temporary files in Swift

   I wrote a small Swift helper to make working with temporary files easier. More >

   March 22, 2018

4. XCTKVOExpectation for native Swift key paths

   I wrote a variant of XCTKVOExpectation that works with native Swift key paths. More >

   February 28, 2018

5. A better NSManagedObjectContext​.performAndWait

   I show an overload of the NSManaged​Object​Context​.perform​Block​And​Wait(_:) method that returns the block’s return value to the caller and supports rethrows. More >

   February 19, 2018