Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Swift 3 - From Expert to Beginner
Search
Wei Wang
July 21, 2016
Programming
2
210
Swift 3 - From Expert to Beginner
A speech for changes in Swift 3.
Wei Wang
July 21, 2016
Tweet
Share
More Decks by Wei Wang
See All by Wei Wang
網路之難,難於上青天 - iPlayground 2019
onevcat
11
4.9k
GMTC 2019 - 在分歧中发展,2019 我们能用 Swift 做什么
onevcat
0
930
从 Swift 到机器学习
onevcat
2
950
iOS Dev - The Dark Side
onevcat
0
120
面向协议编程与 Cocoa 的邂逅
onevcat
14
4.7k
如何打造一个让人愉快的框架
onevcat
4
22k
JSPatch Introduction
onevcat
0
180
Objective-C Runtime Swizzle
onevcat
0
180
Unity Memory
onevcat
0
130
Other Decks in Programming
See All in Programming
WebDriver BiDiとは何なのか
yotahada3
1
140
ペアーズでの、Langfuseを中心とした評価ドリブンなリリースサイクルのご紹介
fukubaka0825
2
300
2,500万ユーザーを支えるSREチームの6年間のスクラムのカイゼン
honmarkhunt
6
5.1k
Amazon S3 TablesとAmazon S3 Metadataを触ってみた / 20250201-jawsug-tochigi-s3tables-s3metadata
kasacchiful
0
100
SpringBoot3.4の構造化ログ #kanjava
irof
2
970
iOSエンジニアから始める visionOS アプリ開発
nao_randd
3
120
Grafana Cloudとソラカメ
devoc
0
140
定理証明プラットフォーム lapisla.net
abap34
1
1.7k
AIの力でお手軽Chrome拡張機能作り
taiseiue
0
170
Amazon Q Developer Proで効率化するAPI開発入門
seike460
PRO
0
110
社内フレームワークとその依存性解決 / in-house framework and its dependency management
vvakame
1
550
Honoとフロントエンドの 型安全性について
yodaka
4
250
Featured
See All Featured
The Illustrated Children's Guide to Kubernetes
chrisshort
48
49k
Building an army of robots
kneath
302
45k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
12
950
The Art of Delivering Value - GDevCon NA Keynote
reverentgeek
10
1.3k
Code Review Best Practice
trishagee
66
17k
Measuring & Analyzing Core Web Vitals
bluesmoon
6
240
A Modern Web Designer's Workflow
chriscoyier
693
190k
How to Ace a Technical Interview
jacobian
276
23k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
27
1.9k
Automating Front-end Workflow
addyosmani
1367
200k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
20
2.4k
Building Applications with DynamoDB
mza
93
6.2k
Transcript
SP TF JP20028 - onevcat Wei Wang 1
Recently 2
Swift From Beginner to Expert JP20028 - onevcat, Nov 2014
3
Swift 3 From Expert to Beginner JP20028 - onevcat, Jul
2016 4
Open + Evolution 5
Swift Evolution Repo1 SE-XXXX New Site: https://apple.github.io/ swift-evolution/ 1 https://github.com/apple/swift-evolution
6
7
Important proposals & Broken APIs 8
SE-0023 API Design Guidelines And SE-0006 Apply API Guidelines to
the Standard Library SE-0005 Better Translation of Objective-C APIs Into Swift SE-0033 Import Objective-C Constants as Swift Types 9
Problems of Current Cocoa APIs • Disordered • Verbose &
Duplicated • For Objective-C. Not Swifty 10
Clarity let text = "Hello world" text.stringByAppendingString(", Swift2") 11
Clarity public func stringByAppendingString(aString: String) -> String 12
Clarity public func stringByAppendingString(aString: String) -> String 13
Clarity public func appending(_ aString: String) -> String 14
Clarity // Swift 2 text.stringByAppendingString(", Swift2") // Swift 3 text.appending(",
Swift3") 15
More Examples // Swift 2 let color = UIColor.blackColor() let
app = UIApplication.sharedApplication() // Swift 3 let color = UIColor.black() // view.backGroundColor = .black() <- Type Infer let app = UIApplication.shared 16
More Examples var array = [1, 2, 3, 4] //Swift
2 array.removeAtIndex(1) // Swift 3 array.remove(at: 1) 17
More Examples let text = "abcde" // Swift 2 text.stringByReplacingOccurrencesOfString(
"abc", withString: "123") // Swift 3 text.replacingOccurrences( of: "abc", with: "123") 18
Exception // Remove KVO observer // Swift 2 app.removeObserver(self, forKeyPath:
"valueKey") // Swift 3 app.removeObserver(self, forKeyPath: "valueKey") // Why not? app.remove(observer: self, for: "valueKey") 19
Exception func removeObserver( _ observer: NSObject, forKeyPath keyPath: String )
When NSObject, Any, AnyObject, Int, String included in method signature: • Declaration is fine. • But using is not so clear. 20
From Swift 2 To 3 Get to be used to
new APIs With Swift migrator Difficulty: ! 21
SE-0088 Modernize libdispatch for Swift 3 naming conventions 22
// Swift 2 let queue = dispatch_queue_create( "my.queue", DISPATCH_QUEUE_CONCURRENT) dispatch_async(queue)
{ doHeavyWork() dispatch_async(dispatch_get_main_queue(), { updateUI() }) } dispatch_after( dispatch_time( DISPATCH_TIME_NOW, Int64(3500 * NSEC_PER_SEC)), dispatch_get_main_queue()) { call() } 23
// Swift 3 let queue = DispatchQueue( label: "my.queue", attributes:
.concurrent) queue.async { doHeavyWork() DispatchQueue.main.async { updateUI() } } let time = DispatchTime.now() + 3.5 DispatchQueue.main.after(when: time) { call() } // Also for group, semaphore, IO etc. 24
Not only GCD... // Swift 2 func rotationAround(offset: CGPoint, angle:
CGFloat, transform: CGAffineTransform = CGAffineTransformIdentity) -> CGAffineTransform { var result = CGAffineTransformTranslate(transform, offset.x, offset.y) result = CGAffineTransformRotate(result, angle) return CGAffineTransformTranslate(result, -offset.x, -offset.y) } 25
// Swift 2 func rotationAround(offset: CGPoint, angle: CGFloat, transform: CGAffineTransform
= CGAffineTransformIdentity) -> CGAffineTransform { var result = CGAffineTransformTranslate(transform, offset.x, offset.y) result = CGAffineTransformRotate(result, angle) return CGAffineTransformTranslate(result, -offset.x, -offset.y) } // Swift 3 func rotationAround(offset: CGPoint, angle: CGFloat, transform: CGAffineTransform = .identity) -> CGAffineTransform { return transform.translateBy(x: offset.x, y: offset.y) .rotate(angle) .translateBy(x: -offset.x, y: -offset.y) } 26
// Swift 2 func trace(in context: CGContext, path: CGPath) {
let red = CGColorCreateGenericRGB(1, 0, 0, 1) CGContextSaveGState(context) CGContextAddPath(context, path) CGContextSetStrokeColorWithColor(context, red) CGContextStrokePath(context) CGContextRestoreGState(context) } // Swift 3 func trace(in context: CGContext, path: CGPath) { let red = CGColor.red context.saveGState() context.addPath(path) context.setStrokeColor(red) context.strokePath() context.restoreGState() } 27
Imported by Compiler from C No Runtime Overhead 28
From Swift 2 To 3 Just forget the legacy C
Difficulty: ! 29
SE-0069 Mutability and Foundation Value Types SE-0086 Drop NS Prefix
in Swift Foundation 30
Value Type is Good 31
Value Type is Good • Immutability • Less State •
Performance 32
Struct • String • Array Class • NSURL • NSDate
• NSData 33
Swift 3 All NS prefix removed: • NSURL → URL
• NSDate → Date • NSData → Data • etc. From Class to Struct. Not an NSObject anymore. 34
public struct URL : ReferenceConvertible, CustomStringConvertible, Equatable { public typealias
ReferenceType = NSURL //... } • Reference type underneath • Value Semantic • Copy-on-Write 35
Still be a class: • NSNotificationCenter → NotificationCenter • NSUserDefaults
→ UserDefaults • etc. 36
From Swift 2 To 3 No NS prefix needed Difficulty:
! 37
SE-0046 Establish consistent label behavior across all parameters including first
labels 38
Swift 2 The first label is omitted by default. func
foo(a: T, b: U, c: V) { } foo(a, b: b, c: c) 39
Swift 3 You need to write the first label by
default: func foo(a: T, b: U, c: V) { } foo(a: a, b: b, c: c) 40
Swift 3 Back compatibility Your current API will be imported
as: func foo(_ a: T, b: U, c: V) { } But you should consider in Swift 3 way and give it a fix. 41
SE-0004 Remove the ++ and -- operators 42
let a = ++x // Plus self (x), then use
let b = x++ // Use, then plus let c = --x // Minus, then use let d = x-- // Use, then minus 43
let a = ++x // Plus self (x), then use
let b = x++ // Use, then plus let c = --x // Minus, then use let d = x-- // Use, then minus var i = 0 if shouldCount { i++ } 44
let a = ++x // Plus self (x), then use
let b = x++ // Use, then plus let c = --x // Minus, then use let d = x-- // Use, then minus (i++)+(++i)+(++i)+(i++)+(i++) = ? // Good luck! 45
From Swift 2 To 3 Stop using ++ and --
Use += instead var i = 0 if shouldCount { i += 1 } Difficulty: ! 46
SE-0025 Scoped Access Level 47
Swift 2 public internal private ← current file 48
Swift 3 public internal fileprivate ← current file private 49
Swift 3 public internal fileprivate private ← current scope 50
// Sample.swift struct MyStruct { private var name: String? func
sayHello() { print("How are you?") } private func damnIt() { print("Damn you!") } // Cannot use `sayMorning` } extention MyStruct { // Cannot use `damnIt` and `name` private func sayMorning() { print("Morning!") sayHello() } } 51
From Swift 2 To 3 Rename private to fileprivate Use
private when really needed Difficulty: ! 52
SE-0047 Defaulting non-Void functions so they warn on unused results
53
In Swift 2 @warn_unused_result(mutable_variant="sortInPlace") public func sort() -> [Self.Generator.Element] 54
In Swift 3 @discardableResult func youCanIgnoreTheReturnValue() -> Int From Swift
2 To 3 Use @discardableResult according to compile warning. Difficulty: ! 55
Bad News 56
• Full of breaking changes • From beginner to expert,
again • Third party support 57
Good News 58
Xcode 8 contains both Swift 2.3 and Swift 3 59
Is it worth upgrading to Swift 3? 60
It depends. 61
Thanks 62