The new version of Swift 3, dubbed Swift 3 in the official documentation, includes the following changes: • Swift 3.1.0 introduces support for Swift 4 and 5 • Swift 3 introduces a new “Forkable” class for working with nested lists, collections, and structs.
Swift 3 also adds a new type for structs called a “shared object” that’s just a pointer to another shared object.
Shared objects can contain references to other objects.
These references can then be referenced by other objects in a shared object, making Swift more expressive and easier to reason about.
• Swift 4.0 has two new methods: “set” and “remove”.
The former is a new way of working with strings, which lets you copy, delete, or modify the contents of a string.
The latter is a more powerful method that removes an existing string.
These two new APIs are supported in Swift 4, along with other language features.
• “ListView” has two major changes: The ListView class can now include “compose” as an attribute to add or remove items in a collection.
This is a feature that’s been available in the standard library since Swift 3 and Swift 4 introduced the compose operator.
Compose items can be used to add new items to a collection and remove items from it.
• The “Swift for iOS” SDK now supports the Apple SDK for Swift 3 for developers, as well as the Swift 3 compiler.
The SDK supports Swift 3 versions 4.2.0 and up.
• Improvements to the Swift for iOS SDK for developers.
The iOS SDK includes Swift 3 support and includes additional Swift 3 features like: • Improved support for the Apple Watch’s vibration control and support for audio-in-waiting (AIF).
• Improved Swift 3 compatibility with the iPhone SDK.
• A new, optional “Swim for macOS” SDK, which includes Swift 4 support.
The macOS SDK includes support for both Swift 3 on macOS and Swift 3 only on macOS.
• Additional Swift 3 API support for iOS devices.
• Improved error reporting in Swift for macOS.
These improvements will roll out over time.
• Other new Swift 3 APIs, including: • The new “swift” type and type family, which supports generics and the creation of generic classes.
Swift 4 introduces the “type family”, which supports generic classes that are used to create classes with an associated type.
Swift for Mac also introduces the Swift family, a new class that is a superset of the type family that is available on macOS platforms.
• Type inference for Swift types, which allows Swift to infer types of arbitrary complexity.
• New methods for creating Swift types using types from existing Swift APIs.
• In Swift 4 for Mac, a compiler error message when a Swift type cannot be constructed.
Swift now understands the following common errors: • An invalid type or property name.
• An error in a type definition.
• Error code that cannot be interpreted as an error.
• Typing a type name with the wrong type qualifier.
• Writing a type that cannot have a type parameter.
• Invalid type parameter or a type field name.
These are the types of errors that Swift for Swift users are more likely to encounter.
Swift has a variety of error messages to help users understand these types of messages.
These errors will be more prominent in the next major release of Swift, which is slated for a December 2018 release.
The next major Swift release will be Swift 4 (or Swift 5).