⚠️ Breaking Changes Ahead ⚠️

Focus now builds with Xcode 9.0 and will be developed in Swift 4.0. While this required no changes to the public API, it means that Xcode 8 toolchains are no longer supported.

Focus now supports Swift 3.1

Focus now supports Swift 3.0 and Xcode 8 as well as the Swift Package Manager and a Linux build.

• Focus now supports Swift 2.2
• An implementation of Setter s has graciously been contributed by (@r-peck). Thanks!

Focus now supports watchOS and tvOS

• Monomorphic aliases for each type has been added in the form of Simple* structs.
• Updates operator definitions.

This release extracts the Lens Family into a number of protocols and protocol extensions to enable more general future versions of Focus.

Focus is an Optics library for Swift that includes Lenses, Prisms, Isos, and the underlying Indexed Monads and Comonads that make it all happen.

The Lens family is a useful way of describing first-class traversals, references, and relationships between data structures and their component parts. In Swift, this presents a fantastic opportunity to recast setters and getters of even mutable objects as immutable views.