Building Android and iOS Apps in F#

F# talk given for Chicago Mobile .NET developers meetup September 25, 2014 at Microsoft Chicago

Transcript

1. Building Android and iOS Apps in F# Bernard Hsu @BernardShoe Founder, All Good People LLC www.letsthinkabout.us (Android, iOS) |> F# |> Xamarin
2. John Backus, October 1956 Credit: http://backreaction.blogspot.com/2007/04/fortran-at-50-inventor-john-backus.html
3. John Backus, 1957 + = <3
5. From LSODE Pack Alan C Hindmarsh 10/23/1978
6. August 1978 http://bit.ly/backus_fun
7. http://bit.ly/backus_fun
8. Lisp, 1959
9. Functional languages attract me because of their simplicity even when solving complex tasks…. A good functional program is like a beautiful poem: you see the pieces of a ‘solution’ come together. -Don Syme, Creator F# https://www.simple-talk.com/opinion/geek-of-the- week/don-syme-geek-of-the-week/
10. http://www.tiobe.com/index.php/c ontent/paperinfo/tpci/index.html
11. The Tao of Functional Programming 1.Immutable Data 2. Function Composition 3. Pattern Matching 4. Lazy Evaluation |> http://bit.ly/backus_fun
12. 1. Immutable Data • No variables, only values • No imperative constructs • For, While loops • No mutable Arrays • No mutable Objects • No mutable strings http://bit.ly/backus_fun
13. 1. Immutable Data Imperative Functional Snippets from http://blogs.msdn.com/b/doriancorompt/archive/2012/01/08/1-recursion-where-are-my-for-while-loops.aspx
14. 1. Immutable Data Imperative Functional
15. The Tao of Functional Programming 1. Immutable Data 2.Function Composition 3. Pattern Matching 4. Lazy Evaluation |>
16. 2. Function Composition Pipe-Forward Operator |> numbers Seq. map square Seq.sum |> |> F# |> (i <3)
17. 2. Function Composition Function Currying
18. The Tao of Functional Programming 1. Immutable Data 2. Function Composition 3.Pattern Matching 4. Lazy Evaluation |>
19. 3. Pattern Matching Switch – Case statements on steroids
20. 3. Pattern Matching
21. The Tao of Functional Programming 1. Immutable Data 2. Function Composition 3. Pattern Matching 4.Lazy Evaluation |>
22. 4. Lazy Evaluation let x = Lazy<int>.Create(fun () -> printfn "Evaluating x..."; 10) let y = lazy(printfn "Evaluating y..."; x.Value + x.Value)
23. Demos • F# Data • http://api.worldbank.org/countries/us/indicators/SP.POP.TOTL?date=2013
24. Demos • Game of Life • http://www.letsthinkabout.us/post/android-game-of-life • http://www.emergentmind.com/game-of-life
25. F# Xamarin • Tools are ready • But not up to C#-par • iOS and Android are OO • Cannot write “pure” functional code • Good for use in Model
26. Building Android and iOS Apps in F# Bernard Hsu @BernardShoe Founder, All Good People LLC www.letsthinkabout.us (Android, iOS) |> |> F# Xamarin