Swift Thinking

I talk about operator overloading and easy type safe JSON parsing in Swift.

Transcript

2. KEITH SMILEY
3. SWIFT THINKING
4. ==(LHS: YOLO)
5. view1.al_left == view2.al_right
6. NSLayoutConstraint(item: view1, attribute: NSLayoutAttribute.Left, relatedBy: NSLayoutRelation.Equal, toItem: view2, attribute: NSLayoutAttribute.Right ...
7. operator infix .... {} @infix func .... (lhs: Int, rhs: Int) -> Range<Int> { return Range(start: Int(arc4random_uniform(UInt32(lhs))), end: Int(arc4random_uniform(UInt32(rhs)))) }
8. for i in 1....5 { println(i) } // Expected: 1 2 3 4 5 // Actual: 1 2 3
9. NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"\\w+" options:0 error:nil]; NSRange range = NSMakeRange(0, string.length) NSUInteger numberOfMatches = [regex numberOfMatchesInString:string options:0 range:range]; if (numberOfMatches > 0) { ... }
10. let regex = NSRegularExpression(pattern: "\\w+", options: nil, error: nil) let range = NSMakeRange(0, countElements(string)) let numberOfMatches = regex.numberOfMatchesInString(string, options: nil, range: range) if numberOfMatches > 0 { ... }
11. if string =~ "\\w+" { ... }
12. -- Haskell matches :: String -> Bool matches x = x =~ "\\w+" # Ruby if string =~ /\w+/ ... end # Shell script... if [[ $string =~ "\w+" ]]; then ... fi
14. // This ~= operator ensures that indexPath.row // is found in the range on the right. if 1...list.count ~= indexPath.row { ... } // Check to see if the key is contained in the array. if ["foo", "bar"] ~= key { ... }
15. date - 2.days() - 1.hour() + 5.minutes()
16. isEqualToString:
17. [thing1 isEqual:thing2];
18. thing1 == thing2
19. { "user": { "username": "Keith", "id": 1 } }
20. id JSON = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error]; NSDictionary *userDict = JSON[@"user"];
21. for (NSDictionary *userDict in JSON) { NSLog(@"%@", userDict[@"username"]); }
22. let JSON: AnyObject = NSJSONSerialization .JSONObjectWithData(data, options: nil, error: &error)
23. if let userDict = JSON as? NSDictionary { if let username = userDict.objectForKey("username") as? String { println(username) } }
24. if let users = JSON as? NSDictionary[] { for userDict in users { if let username = userDict.objectForKey("username") as? String { println(username) } } }
25. if let repos = githubJSON as? NSDictionary[] { for repoDict in repos { if let permissions = repoDict.objectForKey("permissions") as? NSDictionary { if let isAdmin = permissions.objectForKey("admin") as? Bool { if isAdmin { println("They are an admin!") } } } } }
26. if let isAdmin = repoDict["permissions"]?["admin"]?.bool! { if isAdmin { println("They are an admin!") } }
27. if let isAdmin = repoDict["permissions"]["admin"].bool { if isAdmin { println("They are an admin!") } }
28. type User struct { Username string `json:"username"` } var user User err = json.Unmarshal(JSON, &user)
29. data User = User { username :: String , userID :: Integer } deriving (Show) instance FromJSON User where parseJSON (Object j) = User <$> (j .: "username") <*> (j .:? "id") case decode JSON :: Maybe User of Just user -> print user Nothing -> error "Invalid JSON"
30. BEER