Swift 3.0 Released!
Swift 3.0, the first major release of Swift since it was open-sourced, is now officially released! Swift 3 is a huge release containing major improvements and refinements to the core language and Standard Library, major additions to the Linux port of Swift, and the first official release of the Swift Package Manager.
Language Changes
Swift 3.0 is a major language release. It is not source-compatible with Swift 2.2 and 2.3. It contains the following language changes that went through the Swift’s evolution process:
- SE-0002: Removing currying
funcdeclaration syntax - SE-0003: Removing
varfrom Function Parameters - SE-0004: Remove the
++and--operators - SE-0005: Better Translation of Objective-C APIs Into Swift
- SE-0006: Apply API Guidelines to the Standard Library
- SE-0007: Remove C-style for-loops with conditions and incrementers
- SE-0008: Add a Lazy flatMap for Sequences of Optionals
- SE-0016: Adding initializers to Int and UInt to convert from UnsafePointer and UnsafeMutablePointer
- SE-0017: Change
Unmanagedto useUnsafePointer - SE-0019: Swift Testing
- SE-0023: API Design Guidelines
- SE-0025: Scoped Access Level
- SE-0029: Remove implicit tuple splat behavior from function applications
- SE-0031: Adjusting inout Declarations for Type Decoration
- SE-0032: Add
first(where:)method toSequenceType - SE-0033: Import Objective-C Constants as Swift Types
- SE-0034: Disambiguating Line Control Statements from Debugging Identifiers
- SE-0035: Limiting
inoutcapture to@noescapecontexts - SE-0036: Requiring Leading Dot Prefixes for Enum Instance Member Implementations
- SE-0037: Clarify interaction between comments & operators
- SE-0038: Package Manager C Language Target Support
- SE-0039: Modernizing Playground Literals
- SE-0040: Replacing Equal Signs with Colons For Attribute Arguments
- SE-0043: Declare variables in ‘case’ labels with multiple patterns
- SE-0044: Import as Member
- SE-0046: Establish consistent label behavior across all parameters including first labels
- SE-0047: Defaulting non-Void functions so they warn on unused results
- SE-0048: Generic Type Aliases
- SE-0049: Move @noescape and @autoclosure to be type attributes
- SE-0052: Change IteratorType post-nil guarantee
- SE-0053: Remove explicit use of
letfrom Function Parameters - SE-0054: Abolish
ImplicitlyUnwrappedOptionaltype - SE-0055: Make unsafe pointer nullability explicit using Optional
- SE-0057: Importing Objective-C Lightweight Generics
- SE-0059: Update API Naming Guidelines and Rewrite Set APIs Accordingly
- SE-0060: Enforcing order of defaulted parameters
- SE-0061: Add Generic Result and Error Handling to autoreleasepool()
- SE-0062: Referencing Objective-C key-paths
- SE-0063: SwiftPM System Module Search Paths
- SE-0064: Referencing the Objective-C selector of property getters and setters
- SE-0065: A New Model For Collections and Indices
- SE-0066: Standardize function type argument syntax to require parentheses
- SE-0067: Enhanced Floating Point Protocols
- SE-0069: Mutability and Foundation Value Types
- SE-0070: Make Optional Requirements Objective-C-only
- SE-0071: Allow (most) keywords in member references
- SE-0072: Fully eliminate implicit bridging conversions from Swift
- SE-0076: Add overrides taking an UnsafePointer source to non-destructive copying methods on UnsafeMutablePointer
- SE-0077: Improved operator declarations
- SE-0081: Move
whereclause to end of declaration - SE-0085: Package Manager Command Names
- SE-0086: Drop NS Prefix in Swift Foundation
- SE-0088: Modernize libdispatch for Swift 3 naming conventions
- SE-0089: Renaming
String.init<T>(_: T) - SE-0091: Improving operator requirements in protocols
- SE-0092: Typealiases in protocols and protocol extensions
- SE-0093: Adding a public
baseproperty to slices - SE-0094: Add sequence(first:next:) and sequence(state:next:) to the stdlib
- SE-0095: Replace
protocol<P1,P2>syntax withP1 & P2syntax - SE-0096: Converting dynamicType from a property to an operator
- SE-0099: Restructuring Condition Clauses
- SE-0101: Reconfiguring
sizeofand related functions into a unifiedMemoryLayoutstruct - SE-0102: Remove
@noreturnattribute and introduce an emptyNevertype - SE-0103: Make non-escaping closures the default
- SE-0106: Add a
macOSAlias for theOSXPlatform Configuration Test - SE-0107: UnsafeRawPointer API
- SE-0109: Remove the
Booleanprotocol - SE-0111: Remove type system significance of function argument labels
- SE-0112: Improved NSError Bridging
- SE-0113: Add integral rounding functions to FloatingPoint
- SE-0114: Updating Buffer "Value" Names to "Header" Names
- SE-0115: Rename Literal Syntax Protocols
- SE-0116: Import Objective-C
idas SwiftAnytype - SE-0117: Allow distinguishing between public access and public overridability
- SE-0118: Closure Parameter Names and Labels
- SE-0120: Revise
partitionMethod Signature - SE-0121: Remove
OptionalComparison Operators - SE-0124:
Int.init(ObjectIdentifier)andUInt.init(ObjectIdentifier)should have abitPattern:label - SE-0125: Remove
NonObjectiveCBaseandisUniquelyReferenced - SE-0127: Cleaning up stdlib Pointer and Buffer Routines
- SE-0128: Change failable UnicodeScalar initializers to failable
- SE-0129: Package Manager Test Naming Conventions
- SE-0130: Replace repeating
CharacterandUnicodeScalarforms of String.init - SE-0131: Add
AnyHashableto the standard library - SE-0133: Rename
flatten()tojoined() - SE-0134: Rename two UTF8-related properties on String
- SE-0135: Package Manager Support for Differentiating Packages by Swift version
- SE-0136: Memory Layout of Values
- SE-0137: Avoiding Lock-In to Legacy Protocol Designs
Migrating to Swift 3
Swift 3 is a source-breaking release, largely due to the changes in SE-0005 and SE-0006. These changes not only impact the names of the Standard Library APIs, but also completely change how Objective-C APIs (particularly from Cocoa) import into Swift. Many of the changes are largely mechanical, but they can be numerous in a typical Swift project.
To help with moving to Swift 3, Xcode 8.0 contains a code migrator that can automatically handle many of the needed source changes. There is also a migration guide available to guide you through many of the changes — especially through the ones that are less mechanical and require more direct scrutiny.
Documentation
An updated version of The Swift Programming Language for Swift 3.0 is now available on Swift.org. It is also available for free on Apple’s iBooks store.
Platforms
Linux (Ubuntu 14.04 and Ubuntu 15.10)
The Linux port now includes the Swift Core Libraries and the Swift Package Manager.
Official binaries for Ubuntu 14.04 and Ubuntu 15.10 are available for download.
Apple (Xcode)
For development on Apple’s platforms, Swift 3.0 ships as part of Xcode 8.0.
Sources
Development on Swift 3.0 was tracked in the swift-3.0-branch on the following repositories on GitHub:
- swift
- swift-llvm
- swift-clang
- swift-lldb
- swift-cmark
- swift-corelibs-foundation
- swift-corelibs-libdispatch
- swift-corelibs-xctest
- swift-llbuild
- swift-package-manager
The tag swift-3.0-RELEASE designates the specific revisions in those repositories that make up the final version of Swift 3.0.
The swift-3.0-branch will remain open, but under the same release management process, to accumulate changes for a potential future bug-fix “dot” release.