1. F# Eye 4 the C# Guy Phillip Trelford @ptrelford http://trelford.com/blog

3. Thoughtworks Tech RadarJuly 2011

4. Visual F#

5. The F in F# standsfor FUN

6. Halo 3 with F# Skills

7. XBLA: Path to Go – F# AI

8. F# Strongly Typed Functional Object Orientated Open Source .Net language In Visual Studio

9. Functional Programming Pure Functions Higher Order Functions Pattern Matching

10. Pure Functions - Excel

11. Higher Order Functions F# Map/Reduce letmapf xs = seq { for x inxsdo yield f x } letreducefinititems = letmutablecurrent = init for item in items do current <- f current item current C# Map/Reduce publicstatic IEnumerable<R> Map<T, R> (thisIEnumerable<T> xs, Func<T, R> f) { foreach (var x in xs) yieldreturn f(x); } publicstatic R Reduce<T, R> (thisIEnumerable<T> xs, R init, Func<R, T, R> f) { varcurrent = init; foreach (var x in xs) current = f(current, x); return current; }

12. Pattern Matching F# match day with | 0 ->"Sunday" | 1 ->"Monday" | 2 ->"Tuesday" | 3 ->"Wednesday" | 4 ->"Thursday" | 5 ->"Friday" | 6 ->"Saturday" | _ –> invalidArg"Invalid day" C# switch (day) { case0: return"Sunday"; case1: return"Monday"; case2: return"Tuesday"; case3: return"Wednesday"; case4: return"Thursday"; case5: return"Friday"; case6: return"Saturday"; default: thrownew ArgumentException("day"); }

13. demos

14. Light Syntax F# type Person(name:string,age:int) = /// Full name memberperson.Name = name /// Age in years memberperson.Age = age C# publicclassPerson { public Person(string name, int age) { _name = name; _age = age; } privatereadonlystring _name; privatereadonlyint _age; ///<summary> /// Full name ///</summary> publicstring Name { get { return _name; } } ///<summary> /// Age in years ///</summary> publicint Age { get { return _age; } } }

15. Unit Testing toExplorative Testing F# NUnit openNUnit.Framework [<TestFixture>] moduleMathTest = [<Test>] let ``2 + 2 should equal 4`` () = Assert.AreEqual(2 + 2, 4) C# NUnit usingNUnit.Framework; [TestFixture] publicclassTest { [Test] publicvoid TwoPlusTwoShouldEqualFour() { Assert.AreEqual(2 + 2, 4); } }

16. Domain Model - POS typeCode = string type Name = string type Price = decimal type Product = Product of Code * Name * Price type Quantity = decimal typeSaleLineItem = Product * Quantity

17. F# 3.0 (Beta)Type Providers

18. Units of Measure

19. Units in Cells typearithmeticOp = Add | Sub | Mul | Div typelogicalOp = Eq| Lt | Gt | Le | Ge | Ne type formula = | Negof formula | Expof formula * formula | ArithmeticOpof formula * arithmeticOp * formula | LogicalOpof formula * logicalOp * formula | NumofUnitValue | Ref ofint * int | Range ofint * int * int * int | Fun of string * formula list

20. SUMMARY

21. TIOBE Index August 2011 - F# enters Top 20

22. F# Jobs

23. Meet the F#ersTwitter #fsharp

24. F# Books

25. @jbandi #chtd Quote from "future of .net" Have a look at F# for two days and you will find yourself two years ahead of your peer .netdevs. #fsharp

26. Q & A Links http://fsharp.net http://fssnip.net http://tryfsharp.org Contact @ptrelford phil@trelford.com http://trelford.com/blog