Performance, Consistency, Expressiveness, Safety

• Renamings:
  • Some memory management functions have been renamed to be more consistent with the overall terminology.
  • The type Observable.Update has been renamed to Observable.Message.
• Non-optional generic types: Variables and messengers do no longer add implicit optionals to their generic value and message types. This makes it possible to create variables with non-optional values and the code is more explicit and consistent.
  • You can still initialize variables and messengers without argument, when you choose to make their value or message type optional.
• Dedicated observer pools: All observables now maintain their own dedicated pool of observers. This improves many aspects:
  • All observables get highest performance
  • The whole API is more consistent
  • Custom observable implementations are more expressive and customizable
  • Memory management is easier as all observables, when they die, stop their observations
• Meaningful custom observables: Custom observables now adopt the CustomObservable protocol. And they provide a Messenger<Message> instead of the latestUpdate.
  • As long as Swift can't infer the type, you'll also have to specify the associated Message type.
• Consistent variables:
  • The operators on string- and number variables now work on all combinations of optional and non-optional generic and main types. For instance, string concatenation via + works on all pairs of String, String?, Var<String>, Var<String?>, Var<String>? and Var<String?>?.
  • All variables with values of type String, Int, Float and Double also have a non-optional property that is named after the value type (string, int ...).