F# 101

Short introduction to F#.
1. https://github.com/mat3u/kata-fsharp-template - Empty F# solution with NUnit and FAKE
2. https://github.com/MSledzinski/args-parser-fskata - Kata Args Solution (by Marek Śledziński)
3. https://gist.github.com/mat3u/d864d371fe168db36ffe - Sample Game Of Life implementation

Links:

1. http://fsharpforfunandprofit.com
2. http://fsharp.org

Transcript

1. F# Marek Śledziński Mateusz Stasch
2. Marek Śledziński @Marol_sl https://github.com/MSledzinski
3. Mateusz Stasch @mattstasch http://mattstasch.net
4. Functional programming?
6. „But, why F#?” Unknown
7. F# is a mature, open source, cross-platform, functional-first programming language. It empowers users and organizations to tackle complex computing problems with simple, maintainable and robust code.
8. http://dungpa.github.io/fsharp-cheatsheet/ Google -> „fsharp cheatsheet” -> 1st result
9. Immutability & Data Types let a = 5 a = 6 // Error let mutable b = 5 b <- 6 let p = („str”, 5) type Book = { Title: string; Author: Author } let lotr = {Title = „Lord of the Rings”; Author = „J.R.R. Tolkien”} let silm = {lotr with Title = „Silmarilion”}
10. Higher-order function let squares = List.map (fun n -> n * n) [1 .. 100]
11. Higher-order function let squares = List.map (fun n -> n * n) [1 .. 100] let squares = [1 .. 100] |> List.map (fun n -> n * n)
12. Higher-order function let squares = List.map (fun n -> n * n) [1 .. 100] let double a = a + a let doubles = [1 .. 100] |> List.map double let squares = [1 .. 100] |> List.map (fun n -> n * n)
13. Currying let sum a b = a + b
14. Currying let sum a b = a + b (int, int) -> int
15. Currying let sum a b = a + b (int, int) -> int int -> int -> int
16. λ Calculus let f = fun x -> fun y -> x + y let g x y = x + y
17. Partial application let sum a b = a + b let inc = sum 1 inc 5 // 6
18. let rec factorial n = match n with | 0 -> 1 | n -> (factorial (n - 1)) * n Pattern Matching
19. let rec inc list = match list with | [] -> 1 | x::xs -> (x + 1)::(inc xs) Pattern Matching cont.
20. let abs a = match a with | a when a < 0 -> a * -1 | a -> a Pattern Matching cont.
21. let x::xs = [1;2;3] let (x,y) = point let (x,_) = point Pattern Matching cont.
22. let rec factorial n = match n with | 0 -> 1 | n -> (factorial (n - 1)) * n Reccurency & tail call optimization
23. let factorial n = let rec factorial’ n acc match n with | 0 -> acc | n -> factorial’ (n - 1) (n * acc) factorial’ n 1 Reccurency & tail call optimization
24. let factorial n = let rec factorial’ n acc match n with | 0 -> acc | n -> factorial’ (n - 1) (n * acc) factorial’ n 1 Reccurency & tail call optimization
25. open NUnit.Framework open Game [<Test>] let ``Should die if alone`` () = let world = [Cell (0, 0)] let next = step world Assert.IsTrue(next.IsEmpty) Smooth integration with .NET Framework
26. 1.Kata Game Of Life 2.Kata Args
27. 1. Any live cell with fewer than two live neighbours dies, as if caused by underpopulation. 2. Any live cell with more than three live neighbours dies, as if by overcrowding. 3. Any live cell with two or three live neighbours lives on to the next generation. 4. Any dead cell with exactly three live neighbours becomes a live cell.
29. http://www.codingdojo.org/cgi-bin/index.pl?KataArgs https://github.com/MSledzinski/args-parser-fskata.git
30. Hints Pattern matching for list: match my_list with | [] -> … | x::tail -> … | x::y::tail -> … Records and creating new using previous: type Book = { Title: string; Author: Author } let lotr = {Title = „Lord of the Rings”; Author = „J.R.R. Tolkien”} let silm = {lotr with Title = „Silmarilion”} Tail call optimization :)
31. https://github.com/mat3u/kata-fsharp-template http://goo.gl/7j8vQw
32.  http://fsharpforfunandprofit.com/  http://fsharp.org  https://github.com/ChrisMarinos/FSharpKoans