Key Path Expressions as Functions

[stephencelis]

@DevAndArtist

Furthermore you could use isFalse in not function related key-paths ( ! is there too, but it‘s similar to toggle visually far apart and hard to spot.)

Wouldn't it be nice if:

1. Enums had first-class support for key paths.
2. Bool were simply enum Bool { case true, false }

That's all you'd need for \.view.isEnabled.isFalse to be derived automatically ;)