Introduction to FSharp

1. www.dotnet.lv

2. Valdis Iljuconoks Technical Fellow, Software Architect Microsoft MVP Geta AS, Viiar Consulting [email protected] http://dotnet.lv/blogs/vi @ tech_fellow

3. F#

4. what is it?

5. x = x + 1

6. First official functional programming language on .Net

7. why?

8. do more with less see where C# and VB.NET are headed learn new language every year

9. functional object-oriented imperative

10. Theorem proving ISWIM (1966) ML CAML OCAML F#

11. ‘let’ binding

12. let a = 2

13. let a = 2 int a = 2 ≠ // F# // C#

14. let a = 2 static int a() { return 2; } // F# // C#

15. Immutable by default let a = 2 let a = 3 error: FS0037 Duplicate definition of value ‘a’

16. Strong Static Weak Dynamic

17. functions

18. let sqr x = x * x > val sqr : int -> int sqr 5 > val it: int = 25 parameter signature result data type

19. demo sum of sqr of t

20. high order functions A higher-order function is a function that takes another function as a parameter, or a function that returns another function as a value, or a function which does both .

21. let sqr x : float = x * x let mply a b : float = a * b let mplyPI a = mply a 3.14159 let cylinderVolume radius length = mplyPI length * sqr radius

22. demo function pipelining (|>)

23. demo function composition (>>)

24. discriminated unions

25. type NullableInt = | Value of int | Nothing of unit match x with | Value -> ... | Nothing -> ...

26. interoperability

27. demo .Net interoperability

28. First official functional programming language on .Net

29. ?

30. Valdis Iljuconoks Technical Fellow, Software Architect Microsoft MVP Geta AS, Viiar Consulting [email protected] http://dotnet.lv/blogs/vi @ tech_fellow

31. www.dotnet.lv