Swift - Pushing technology limits

Why Swift is Awesome!!!

Transcript

1. Kostiantyn Koval 1 Rocketfarm.no
2. Swift - Pushing technology limits
3. How should look Modern Language?
4. Clean and Clear
5. Programs must be written for people to read, and only incidentally for machines to execute 1 Harold Abelson
6. .global _start .text _start: # write(1, message, 13) mov $1, %rax mov $1, %rdi mov $message, %rsi mov $13, %rdx syscall message: .ascii "Hello, world\n" mov rax, 1 mov rdi, 1 mov rsi, message mov rdx, 13 syscall
8. int compare(const void * a, const void * b) { if ( *(uint32_t*)a < *(uint32_t*)b ) { return -1; } if ( *(uint32_t*)a > *(uint32_t*)b ) { return 1; } return 0; }
9. !
10. @interface Person : NSObject @property (nonatomic) NSString* name; @property (nonatomic) NSInteger age; @end @implementation Person - (instancetype)initWith:(NSString *)name age:(NSInteger)age { self = [super init]; if (self) return nil; _name = name; _age = age; return self; } @end @implementation TestPerson - (void)test { NSArray *people = @[ [[Person alloc] initWith:@"Sam" age:10], [[Person alloc] initWith:@"Sara" age:24], [[Person alloc] initWith:@"Ola" age:42], [[Person alloc] initWith:@"Jon" age:19]]; NSArray *kids = [people filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"age < 18"]]; NSMutableArray *names = [NSMutableArray new]; for (Person *person in people) { [names addObject:person.name.lowercaseString]; } } @end
11. !
12. struct Person { let name: String let age: Int } let people = [ Person(name: "Sam", age: 10), Person(name: "Sara", age: 24), Person(name: "Ola", age: 42), Person(name: "Jon", age: 19)] let kids = people.filter { person in person.age < 18 } let names = people.map { $0.name.lowercaseString }
13. !
14. 60% Less Code 13 Lines Vs 34 Lines
15. Less Code Less Bugs Less money
16. Type inference var age = 19 var name = "Sara" var isEmpty = name.isEmpty VS var age: Int = 19 var name: String = "Sara" var isEmpty: Bool = name.isEmpty
17. No Semicolons ; var age = 19
18. Other 4 Closures 4 Default initializers 4 Default parameters 4 Subscripts 4 Operators
19. //Closures let numbers = [1, 2, 3, 4] numbers.map {$0 + 10} // Subscripts let num2 = numbers[2] //Operators infix operator <<< { } func <<< (a: Vector, b: Vector) -> Vector { return Vector(x: a.x + b.x, y: a.y + b.y) }
20. Smart
21. Features Rich
22. Features Reach 4 Functional Programming 4 OOP 4 Generic Purpose 4 Value types 4 Tuples 4 Optionals 4 ...
23. Safe
24. Safe 4 Types 4 Type casting 4 tUpos 4 Existing Methods 4 Correct instructions - Exception
26. Error Handling func readFromFile(file: String) -> (result: String?, error: NSError?) { return ("file Content", nil) } let result = readFromFile("file.txt") if result.error != nil { println("handle error") }
27. Optionals
28. Optionals 4 Represent absence of a value 4 Safe Nil handling [NullPointerException] 4 Nil value for Value type, Int: 0, -1, NSnotFound, IntMax
29. '?' Type String != String? Int != Int? func person(name: String) -> Person func person(name: String, age: Int?) -> Person person("Elvis", age: nil) person(nil, age: 27) //Error
30. Optionals Is a Box that could store a value inside or could be empty You can interact with the value only throw Box API
31. Safe var person: Person? = people.find("Elvis") // 1 - Unwrapping `!` if person != nil { println("found \(person!)") } //2 - Optional binding if let person = person { println("found \(person)") } else { println("found found") }
32. Multithreading
33. Multithreading 4 Immutable value type 4 explicit 'self' capturing processAsync(var people: [Peope]) -> [Peope] { // ... Run Async people.remove(...) return people } var people: [People] //Async code processAsync(people) processAsync(people) processAsync(people)
34. Fast
35. Fast 18 Times > Objetive-C 2,9 Times > C
36. Let's make better mistakes tomorrow
37. Thanks! QA?? ! Twitter - @KostiaKoval GitHub - /KostiaKoval Kostiantyn Koval - Rocketfarm.no