InterConnect: Server Side Swift for Java Developers

InterConnect2017

6190: Server-Side Swift: An Introduction for Java EE Developers

Chris BaileySTSM, Technical Architect Java, Node.js and Swift at IBM

Stephan Knitelius, Senior ConsultantFaktor Zhen AG

Swift ProgrammingSafe | Expressive | Fast

Hello World

Swift: Hello World

print("Hello, world!")

Swift: Hello World

print("Hello, world!")

> swift main.swift

Swift: Hello World

print("Hello, world!")

> swift main.swift > main

Swift: Hello World

print("Hello, world!")

> swift main.swift > main "Hello, world!"

Swift: Hello World

let event = ”InterConnect"

print("Hello, \(event)”)

Swift: Hello World

let event = ”InterConnect"

print("Hello, \(event)”)

> swift main.swift

Swift: Hello World

let event = ”InterConnect"

print("Hello, \(event)”)

> swift main.swift > main "Hello, InterConnect"

Swift: Hello World

let event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

Swift: Hello World

let event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

> swift main.swift

Swift: Hello World

let event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

> swift main.swift error: cannot assign to value: 'event' is a 'let' constant

Swift: Hello World

let event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

Swift: Hello World

let event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

Swift: Hello World

var event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

Swift: Hello World

var event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

> swift main.swift

Swift: Hello World

var event = "InterConnect" event = "Somewhere else" print("Hello, \(event)”)

> swift main.swift > main "Hello, Somewhere else"

Swift: Hello World

Functions

func addInts(a: Int, b: Int) -> Int { return a + b }

Swift: Functions

func addInts(a: Int, b: Int) -> Int { return a + b }

addInts(a: 1, b: 3)

Swift: Functions

func addInts(_ a: Int, _ b: Int) -> Int { return a + b }

Swift: Functions

func addInts(_ a: Int, _ b: Int) -> Int { return a + b }

addInts(1, 3)

Swift: Functions

func move(from start: Point, to end: Point) -> Bool { /* code */ }

Swift: Functions

func move(from start: Point, to end: Point) -> Bool { /* code */ }

move(from: a, to: b)

Swift: Functions

func minAndMax(numbers: Int...) -> (min: Int, max: Int) {

}

Swift: Functions and Tuples

func minAndMax(numbers: Int...) -> (min: Int, max: Int) { var min = numbers[0] var max = numbers[0] for number in numbers { if number > max { max = number } else if number < min { min = number } } return (min, max) }

Swift: Functions and Tuples

func minAndMax(numbers: Int...) -> (min: Int, max: Int) { var min = numbers[0] var max = numbers[0] for number in numbers { if number > max { max = number } else if number < min { min = number } } return (min, max) }

let result = minAndMax(1, 2, 3, 4, 5)

Swift: Functions: Varargs and Tuples

func minAndMax(numbers: Int...) -> (min: Int, max: Int) { var min = numbers[0] var max = numbers[0] for number in numbers { if number > max { max = number } else if number < min { min = number } } return (min, max) }

let result = minAndMax(1, 2, 3, 4, 5) print(result.min) print(result.max)

Swift: Functions: Varargs and Tuples

Control Flow

let expenseCosts = [34.4, 30.99, 250.0]

var sum: Double = 0

for expense in expenseCosts { sum += expense }

print("total cost is \(sum)")

Swift: Loops and Iterators

let flavour = "Vanilla"

switch flavour { case "Chocolate": print("Quite nice") case "Strawberry", "Rum'n'raisin": print("Very nice") case let str where str.hasPrefix("Mint"): print("UGH!!!, I hate \(str)") default: print("No opinion about this") }

Swift: Switch Statements

let flavour = "Vanilla"

switch flavour { case "Chocolate": print("Quite nice") case "Strawberry", "Rum'n'raisin": print("Very nice") case let str where str.hasPrefix("Mint"): print("UGH!!!, I hate \(str)") default: print("No opinion about this") }

> swiftc main.swift > main

Swift: Switch Statements

let flavour = "Vanilla"

switch flavour { case "Chocolate": print("Quite nice") case "Strawberry", "Rum'n'raisin": print("Very nice") case let str where str.hasPrefix("Mint"): print("UGH!!!, I hate \(str)") default: print("No opinion about this") }

> swiftc main.swift > main "No opinion about this"

Swift: Switch Statements

let flavour = "Mint Chocolate"

switch flavour { case "Chocolate": print("Quite nice") case "Strawberry", "Rum'n'raisin": print("Very nice") case let str where str.hasPrefix("Mint"): print("UGH!!!, I hate \(str)") default: print("No opinion about this") }

Swift: Switch Statements

let flavour = "Mint Chocolate"

switch flavour { case "Chocolate": print("Quite nice") case "Strawberry", "Rum'n'raisin": print("Very nice") case let str where str.hasPrefix("Mint"): print("UGH!!!, I hate \(str)") default: print("No opinion about this") }

> swiftc main.swift > main

Swift: Switch Statements

let flavour = "Mint Chocolate"

switch flavour { case "Chocolate": print("Quite nice") case "Strawberry", "Rum'n'raisin": print("Very nice") case let str where str.hasPrefix("Mint"): print("UGH!!!, I hate \(str)") default: print("No opinion about this") }

> swiftc main.swift > main "UGH!!!, I hate Mint Chocolate"

Swift: Switch Statements

let numbers = [1, 2, 3]

numbers.map({ (number: Int) -> Int in return number * 5 }) // [5, 10, 15]

numbers.map({ number in number * 5 })

numbers.map { $0 * 5 }

Swift: Closures

Data Types

class Square {

var area: Double = 0

init(sideLength: Double) { self.sideLength = sideLength } var sideLength: Double { get { return sqrt(area) } set { area = newValue * newValue } } }

Swift: Classes

struct Point { var x: Int var y: Int func description() -> String { return "x=\(x), y=\(y)" } }

var coord = Point(x: 2, y: 4)

var newCoord = coord coord.x = 4

print(coord.description()) // x=4, y=4 print(newCoord.description()) // x=2, y=4

Swift: Structs

enum ApprovalStatus { case PendingOn(String) case Denied case Approved(String) }

var status = ApprovalStatus.PendingOn("Joe Bloggs")

status = .Approved("13213-4341321-2")

switch status { case .PendingOn(let approver): print("Request pending on approval from \(approver)") case .Denied: print("Request DENIED") case .Approved(let code): print("Request approved - auth code \(code)") }

Swift: Enums

Concurrency

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

import Dispatch

let serialQueue = DispatchQueue(label: "serial queue")

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

import Dispatch

let serialQueue = DispatchQueue(label: "serial queue")

serialQueue.async { print("run on serial queue") } serialQueue.asyncAfter(deadline: .now() + DispatchTimeInterval.seconds(1)) { print("run on serial queue") }

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

import Dispatch

let concurrentQueue = DispatchQueue(label: "concurrent queue", attributes: .concurrent)

concurrentQueue.async { print("run on concurrent queue") }

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

import Dispatch

let queue = DispatchQueue(label: "group queue", attributes: .concurrent) let group = DispatchGroup()

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

import Dispatch

let queue = DispatchQueue(label: "group queue", attributes: .concurrent) let group = DispatchGroup()

queue.async(group: group) { print("work 1") }

queue.async(group: group) { print("work 2") }

aqueue-FIFOputtaskintoqueuetoexecute

dequeuedtasksarebeingexecuted

inwai8ngSerial or Concurrent FIFO Queue

Waiting TasksTasks AddedTo Queue

Tasks RemovedFor Execution

import Dispatch

let queue = DispatchQueue(label: "group queue", attributes: .concurrent) let group = DispatchGroup()

queue.async(group: group) { print("work 1") }

queue.async(group: group) { print("work 2") }

group.notify(queue: queue) { print("all work completed") }

Swift ProgrammingSafe | Expressive | Fast

Swift ProgrammingSafe | Expressive | Fast

Swift @ IBM

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

SwiftJava

Swift @ IBM

func length(of string: String) -> Void { print(string.characters.count) }

var str: String? = nil

length(of: str)

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

SwiftJava

Swift @ IBM

func length(of string: String) -> Void { print(string.characters.count) }

var str: String? = nil

length(of: str)

> swiftc main.swift

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java

SwiftJava

Swift @ IBM

func length(of string: String) -> Void { print(string.characters.count) }

var str: String? = nil

length(of: str)

> swiftc main.swift

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java >

SwiftJava

Swift @ IBM

func length(of string: String) -> Void { print(string.characters.count) }

var str: String? = nil

length(of: str)

> swiftc main.swift > Error line 7: Value of optional type ‘String?’ not unwrapped; > did you mean to use ‘!’ or ‘?’?

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java >

SwiftJava

Swift @ IBM

func length(of string: String) -> Void { print(string.characters.count) }

var str: String? = nil

length(of: str)

> swiftc main.swift > Error line 7: Value of optional type ‘String?’ not unwrapped; > did you mean to use ‘!’ or ‘?’?

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java > java Test

SwiftJava

Swift @ IBM

func length(of string: String) -> Void { print(string.characters.count) }

var str: String? = nil

length(of: str)

> swiftc main.swift > Error line 7: Value of optional type ‘String?’ not unwrapped; > did you mean to use ‘!’ or ‘?’?

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java > java Test Exception in thread "main" java.lang.NullPointerException at Test.length(Test.java:5) at Test.main(Test.java:11)

SwiftJava

var optionalString: String? = nil

var string: String = optionalString

Swift: Structs

var optionalString: String? = nil

var string: String = optionalString

> swiftc main.swift

Swift: Structs

var optionalString: String? = nil

var string: String = optionalString

> swiftc main.swift error: value of optional type 'String?' not unwrapped; did you mean to use '!' or ‘?'? var string: String = optionalString ^

Swift: Structs

var optionalString: String? = nil

var string: String = optionalString!

Swift: Structs

var optionalString: String? = nil

var string: String = optionalString!

> swiftc main.swift

Swift: Structs

var optionalString: String? = nil

var string: String = optionalString!

> swiftc main.swift > main

Swift: Structs

var optionalString: String? = nil

var string: String = optionalString!

> swiftc main.swift > main fatal error: unexpectedly found nil while unwrapping an Optional value

Swift: Structs

var optionalString: String? = nil

guard var string: String = optionalString else { print(‘Error! Null string found’) }

Swift: Structs

var optionalString: String? = nil

guard var string: String = optionalString else { print(‘Error! Null string found’) }

> swiftc main.swift

Swift: Structs

var optionalString: String? = nil

guard var string: String = optionalString else { print(‘Error! Null string found’) }

> swiftc main.swift > main “Error! Null string found”

Swift: Structs

Swift ProgrammingSafe | Expressive | Fast

func move(from start: Point, to end: Point) -> Bool { /* code */ }

Swift: Functions

func move(from start: Point, to end: Point) -> Bool { /* code */ }

move(from: a, to: b)

Swift: Functions

Swift @ IBM

public class Test { private static void length (String string){ System.out.println(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

SwiftJava

Swift @ IBM

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

SwiftJava

Swift @ IBM

func length(of string: String) -> Int { return(string.characters.count) }

var str: String = ”MyString”

length(of: str)

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

SwiftJava

Swift @ IBM

func length(of string: String) -> Int { return(string.characters.count) }

var str: String = ”MyString”

length(of: str)

> swiftc main.swift

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java

SwiftJava

Swift @ IBM

func length(of string: String) -> Int { return(string.characters.count) }

var str: String = ”MyString”

length(of: str)

> swiftc main.swift

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java >

SwiftJava

Swift @ IBM

func length(of string: String) -> Int { return(string.characters.count) }

var str: String = ”MyString”

length(of: str)

> swiftc main.swift > Warning: result of call to ‘length(of:)’ is unused

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java >

SwiftJava

Swift @ IBM

@discardableResult func length(of string: String) -> Int { return(string.characters.count) }

var str: String = ”MyString”

length(of: str)

> swiftc main.swift

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java >

SwiftJava

Swift @ IBM

@discardableResult func length(of string: String) -> Int { return(string.characters.count) }

var str: String = ”MyString”

length(of: str)

> swiftc main.swift >

public class Test { private static int length (String string){ return(string.length()); } public static void main(String[] args){ String string = null; length(string); } }

> javac Test.java >

SwiftJava

Swift ProgrammingSafe | Expressive | Fast

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http://benchmarksgame.alioth.debian.org/u64q/performance.php?test=spectralnorm

Typed vs Untyped Performance

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Kitura + LibertyDemo

https://github.com/sknitelius/RacketenMessages-Swift https://github.com/sknitelius/RacketenMessages-Java

JSON Parsing

Persistence

94 1/17/17

GATEWAY

PUBLIC NETWORK CLOUD NETWORK

Client Devices Hosted Services

ROUTING PROXY

Micro-ServicesBackend For Frontend(BFF)

Questions?

Bluemix Mobile & Omni-Channel!BMO-6321: Patterns in Omni-Channel Cloud Application Development

Containers & Microservices!BMC-2173: Introduction to Docker Containers and Microservices

Visit the DevZone in the Concourse for open Hello World labs and Ask Me Anything booths!

Wednesday, 11:15 AM - 12:00 PM | South Pacific C | Session ID: 6321A

Tuesday, 4:45 PM - 5:30 PM | South Pacific A | Session ID: 2173A

Tuesday, 11:00 AM - 12:45 PM | DevZone Ask Me Anything # 2 | Session ID: 7087AAsk Me Anything: Bluemix Cloud-Native Development

Ask Me Anything: Server-Side Swift DevelopmentWednesday, 2:30 PM - 5:00 PM | DevZone Ask Me Anything # 6 | Session ID: 7088A

Node.js & LoopBackBAP-1117: Introduction to LoopBackNode.js Framework

Liberty & MicroservicesBAP - 5081: Microservices with IBM WebSphere Liberty:What, Why and When?

Wednesday, 11:15 AM - 12:00 PM | Islander F | Session ID: 1117A

Tuesday, 7:00 PM - 7:20 PM | Engagement Theater Booth #319 | Session ID: 5081A

1/17/17

Please noteIBM’s statements regarding its plans, directions, and intent are subject to change or withdrawal without notice at IBM’s sole discretion.

Information regarding potential future products is intended to outline our general product direction and it should not be relied on in making a purchasing decision.

The information mentioned regarding potential future products is not a commitment, promise, or legal obligation to deliver any material, code or functionality. Information about potential future products may not be incorporated into any contract.

The development, release, and timing of any future features or functionality described for our products remains at our sole discretion.

Performance is based on measurements and projections using standard IBM benchmarks in a controlled environment. The actual throughput or performance that any user will experience will vary depending upon many factors, including considerations such as the amount of multiprogramming inthe user’s job stream, the I/O configuration, the storage configuration, and the workload processed. Therefore, no assurance can be given that an individual user will achieve results similar to those stated here.

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Notices and disclaimersCopyright © 2017 by International Business Machines Corporation (IBM). No part of this document may be reproduced or transmitted in any form without written permission from IBM.

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Information in these presentations (including information relating to products that have not yet been announced by IBM) has been reviewed for accuracy as of the date of initial publication and could include unintentional technical or typographical errors. IBM shall have no responsibility to update this information. This document is distributed “as is” without any warranty, either express or implied. In no event shall IBM be liable for any damage arising from the use of this information, including but not limited to, loss of data, business interruption, loss of profit or loss of opportunity. IBM products and services are warranted according to the terms and conditions of the agreements under which they are provided.

IBM products are manufactured from new parts or new and used parts. In some cases, a product may not be new and may have been previously installed. Regardless, our warranty terms apply.”

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Performance data contained herein was generally obtained in a controlled, isolated environments. Customer examples are presented as illustrations of how those customers have used IBM products and the results they may have achieved. Actual performance, cost, savings or other results in other operating environments may vary.

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Notices and disclaimers continuedInformation concerning non-IBM products was obtained from the suppliers of those products, their published announcements or other publicly available sources. IBM has not tested those products in connection with this publication and cannot confirm the accuracy of performance, compatibility or any other claims related to non-IBM products. Questions on the capabilities of non-IBM products should be addressed to the suppliers of those products. IBM does not warrant the quality of any third-party products, or the ability of any such third-party products to interoperate with IBM’s products. IBM expressly disclaims all warranties, expressed or implied, including but not limited to, the implied warranties of merchantability and fitness for a particular, purpose.

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