A swift 4 KeyPath journey

Introduction to KeyPaths in swift 4 and some insights on what we can build with them. Meetup presentation on 07/09/2017.
https://www.meetup.com/The-Munich-iOS-Developers-Meetup/events/242585670/

Follow-up Article soon - http://elm4ward.github.io

Transcript

1. \Pen.pineapple.apple.pen A Swift 4 KeyPath Journey including el duderino, erased types, & a thinking cat Pikotaro - PPAP Elmar Kretzer - @elmkretzer
2. KeyWhat? new Swift 4 feature w/ more than 10 yrs Obj-C xp [dude setValue:@"lebowski" forKey:@"lastname"]; The Big Lebowski © Copyright Gramercy Pictures
3. the basics AnyKeyPath PartialKeyPath<Root> KeyPath<Root, Value> WritableKeyPath<Root, Value>
4. like a getter A) straight forward B) wrapped in function C) by KeyPath
5. like a setter A) straight forward B) wrapped in function C) by KeyPath
6. chain’em
7. any special tricks? https://www.instagram.com/corgnelius/ actually cool
8. supports type inferrence Generic Typealias for some optional something from a list of somethings Actually, something is an Int
9. supports optionals Chained optional properties - but only read
10. supports appending 1. KeyPath from Dictionary<String,Int> to Dictionary<String,Int>.Keys 2. KeyPath from Dictionary<String, Int>.Keys to Int 3. Compose both
11. A single expression that defines types and logic. so what?
12. ... so let’s assume two distinct types & we want to map from one to the other and back again. Read & Write with same Expression...
13. LIVE CODING
14. Thanks for listening Follow-Up article including gists on: http://elm4ward.github.io/ Twitter: @elmkretzer