Swift 3.0

Swift 3.0 Preview 1 Released!

JUNE 13, 2016Ted Kremenek Ted Kremenek

We are very pleased to announce Developer Preview 1 of Swift 3.0!

As described in the Swift 3.0 Release Process, developer previews (i.e., “seeds” or “betas”) provide qualified builds of Swift 3 that are more stable than just grabbing the latest snapshot of master (i.e., tip-of-trunk development). Developer previews capture Swift 3 as a work-in-progress and should not be considered the final version of Swift 3 unless otherwise stated.

Implemented Swift Evolution Proposals

The following Swift Evolution proposals are newly implemented in Swift 3.0 Preview 1:

SE-0002: Removing currying func declaration syntax

SE-0003: Removing var from 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 Unmanaged to use UnsafePointer

SE-0019: Swift Testing

SE-0023: API Design Guidelines

SE-0028: Modernizing Swift’s Debugging Identifiers (__FILE__, etc)

SE-0029: Remove implicit tuple splat behavior from function applications

SE-0031: Adjusting inout Declarations for Type Decoration

SE-0032: Add first(where:) method to SequenceType

SE-0033: Import Objective-C Constants as Swift Types

SE-0034: Disambiguating Line Control Statements from Debugging Identifiers

SE-0037: Clarify interaction between comments & operators

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-0053: Remove explicit use of let from Function Parameters

SE-0054: Abolish ImplicitlyUnwrappedOptional type

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-0061: Add Generic Result and Error Handling to autoreleasepool()

SE-0062: Referencing Objective-C key-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-0069: Mutability and Foundation Value Types

SE-0070: Make Optional Requirements Objective-C-only

SE-0071: Allow (most) keywords in member references

SE-0085: Package Manager Command Names

SE-0094: Add sequence(first:next:) and sequence(state:next:) to the stdlib

Downloads

Apple (Xcode)

Swift 3.0 Preview 1 is available for free as part of Xcode 8 beta 1.

Linux (Ubuntu 14.04 and Ubuntu 15.10)

Official binaries for Ubuntu 14.04 and Ubuntu 15.10 are available for download on Swift.org.

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.

Foundation and Linux (Core Libraries)

Not all of the NS prefix removal changes have propagated to the Core Libraries implementation of Foundation APIs. This should be resolved in a future beta.

Migrating to Swift 3

Swift 3 is a source-breaking release over Swift 2.2.1. It contains many syntactic refinements and improvements, but also a huge number of changes for how Objective-C APIs import into Swift due to SE-0005. Please consult the migration guide for guidance and tips for migrating to Swift 3.

北京时间6月14日，苹果开源语言的高级经理Ted Kremenek在Swift官方博客上发布了一篇题为“Swift 3.0 Preview 1 Released!”的文章，介绍了Swift 3.0的第一个开发者预览版：

正如Swift 3.0发布流程中提到的那样，新的3.0开发者预览版（包括seed或beta版）提供了合格的Swift 3 build包，而不仅是抓取master分支（即tip-of-trunk开发）上的最新快照，这种方式所提供的Swift库更为稳定。

目前Swift 3的所有开发者预览版都还处于开发阶段，若非特别注明，都不是Swift 3的最终版。

下面列出了本次在Swift 3.0开发者预览版第一版中所实现的Swift改进提案，此前为大家关注的几项变动也在其中：

SE-0002: 删除currying func声明语法

SE-0003: 函数参数中不再使用var关键字

SE-0004: 删除++与–操作符

SE-0005: 将Objective-C的API更好地接入Swift中

SE-0006: 将API指南应用于标准库中

SE-0007: 移除了C语言风格的for循环（条件与增量下）

SE-0008: 为可选序列增加一个Lazy flatMap

SE-0019: Swift测试

SE-0023: API设计指南

SE-0028: 更新Swift的debug标识符（如__FILE__等）

SE-0048: 泛型类型别名

SE-0049: 将声明式@noescape与@autoclosure改为类型属性

其他变更还有：