![More Code! //F# #light open System let a = 2 Console.WriteLine a //C# using System; namespace ConsoleApplication1 { class Program { static int a() { return 2; } static void Main( string [] args) { Console .WriteLine(a); } } }](https://image.slidesharecdn.com/fsharpleonbrevised-1222325849179385-8/85/F-Eye-for-the-C-Guy-44-320.jpg)
F# Eye for the C# Guy
- 1. F# Eye for the C# guy Leon Bambrick, secretGeek.net
- 2. F#... Do not be afraid.
- 3. hello
- 4. I’m F #
- 6. functional
- 7. Purely functional… Avoid Side- Effects!
- 8. Purely functional… Avoid Mutation!
- 9. Purely functional… No Variables! Only Functions!
- 10. Purely functional… Same input -> Same output!
- 11. No Shared State Purely functional…
- 12. Why learn F#?
- 13. Do More With Less “ If I was using F# I’d be done by now” Why learn F#?
- 14. Do More With Less “ If I was using F# I’d be done by now” See where C# and VB.net are headed Why learn F#?
- 15. Do More With Less “ If I was using F# I’d be done by now” See where C# and VB.net are headed “ Learn one new language every year” (or two) Why learn F#?
- 16. Moore’s Law Keeps Going! Why learn F#?
- 17. But computers are not getting faster Why learn F#?
- 18. Data Grows Quickly But # of Dimensions Grows much faster! And semi-structured data outgrowing structured Entropy Increasing Complexity is through the roof!
- 19. “ Software gets slower faster than hardware gets faster” --Wirth’s Law
- 21. Some stuff is now cheap! Ram Disk Cores Some stuff remains expensive! Time Concurrency Locking Computer Economics is Changing
- 22. Some stuff is now cheap! Ram Disk Cores Some stuff remains expensive! Time Concurrency Locking Computer Economics is Changing
- 23. Some stuff is now cheap! Ram Disk Cores Some stuff remains expensive! Time Concurrency Locking Computer Economics is Changing
- 24. Some stuff is now cheap! Ram Disk Cores Some stuff remains expensive! Real Time Concurrency Locking Computer Economics is Changing
- 25. This tips the balance toward higher abstractions
- 26. Some Applications of F# “ Computationally intensive” work Map/Reduce over internets Financial Analysis Advertising Analysis SQL Data Mining XNA Games Development Web tools, Compile F# to Javascript
- 27. Think About Game Programming
- 28. Game Programming Involves… 3D Animation Rendering Shading Simulation (e.g. physics) Collision Detection AI Opponents
- 29. Genealogy of F # … Theorem proving and ISWIM
- 30. Genealogy of F # … Theorem proving and ISWIM begat: ML “Meta Language”
- 31. Genealogy of F # … Theorem proving and ISWIM begat: ML “Meta Language”, which begat: CAML
- 32. Genealogy of F # … Theorem proving and ISWIM begat: ML “Meta Language”, which begat: CAML, which in turn begat OCaml Oh!
- 33. Genealogy of F # … Theorem proving and ISWIM begat: ML “Meta Language”, which begat: CAML, which in turn begat OCaml, which in turn begat F# ... a sort of OCaml.net (plus more) Oh!
- 34. WTF # ? First official functional language on .net
- 35. WTF # ? First official functional language on .net Deep support thanks to Generics
- 36. WTF # ? First official functional language on .net Deep support thanks to Generics Assimilated by dev-div
- 37. WTF # ? First official functional language on .net Deep support thanks to Generics Assimilated by dev-div Will ship in VS.next
- 38. Code! Finally!
- 39. Code! //F# let a = 2
- 40. Code! //F# let a = 2 The ‘let’ keyword represents a binding between a value and an expression tree.
- 41. Code! //F# let a = 2 The ‘let’ blah blah blahblah blah blahblah blahblah blah blah blah blah blah blah.
- 42. Code! //F# let a = 2 //C# int a = 2 ≠
- 43. Code! //F# let a = 2 //C# //a function! static int a() { return 2; } More like
- 44. More Code! //F# #light open System let a = 2 Console.WriteLine a //C# using System; namespace ConsoleApplication1 { class Program { static int a() { return 2; } static void Main( string [] args) { Console .WriteLine(a); } } }
- 45. More Code! //F# #light open System let a = 2 Console.WriteLine a More Noise Than Signal!
- 46. More Code! //F# #light open System let a = 2 Console.WriteLine a Looks Weakly typed? Maybe Dynamic?
- 47. F#?
- 48. F#
- 50. F# Yet Versatile
- 51. More Code! //F# #light open System let a = 2 Console.WriteLine a Type Inference
- 52. let a = 2 let a = 3 error: FS0037: Duplicate definition of value 'a' Immutable by default
- 53. let square x = x * x > val square : int -> int square 5 > val it : int = 25 simple function…
- 54. let square x = x * x > val square : int -> int square 5 > val it : int = 25 simple function… Parameter
- 55. let square x = x * x > val square : int -> int square 5 > val it : int = 25 simple function… “ Signature”
- 56. let square x = x * x > val square : int -> int square 5 > val it : int = 25 simple function… Types are “inferred”
- 57. Discriminated union types type NullableInt = | Value of int | Nothing of unit
- 58. Discriminated union types type NullableInt = | Value of int | Nothing of unit Wish C#/“O-O” had this.
- 59. Discriminated union types type NullableInt = | Value of int | Nothing of unit “ O-O” has discriminated union envy When the only tool you have is a hammer Everything looks like a nail
- 60. Discriminated union types type NullableInt = | Value of int | Nothing of unit “ O-O” has discriminated union envy When the only tool you have is a hammer Everything looks like a nail e.g. “Inheritance” ends up being used in places where it’s not a perfect fit…
- 61. Discriminated union types type NullableInt = | Value of int | Nothing of unit “ O-O” has discriminated union envy When the only tool you have is a hammer Everything looks like a nail e.g. “Inheritance” ends up being used in places where it’s not a perfect fit… ‘ Discriminated union types’ -- a better fit for some problems?
- 62. Another great tool is “pattern matching”
- 63. Another great tool is “pattern matching” “ Switch/Case” statements on steroids
- 64. Another great tool is “pattern matching” “ Switch/Case” statements on steroids “ method overloads” on crack
- 65. Discriminated unions example type Weapon = | Knife | Gun | Bomb
- 66. Pattern Matching type Weapon = | Knife | Gun | Bomb //block any weapon! let block w = match w with | Knife | Gun -> disarm w | _ -> difuse w block Gun block Knife block Bomb
- 67. Pattern Matching type Weapon = | Knife | Gun | Bomb //block any weapon let block w = match w with | Knife | Gun -> disarm w | _ -> difuse w block Gun block Knife block Bomb
- 68. Lazy is a virtue let lazy_square x = lazy ( print_endline “thinking...“ x * x ) let lazy_square_ten = lazy_square 10 //first time: “thinking…” Lazy.force (lazy_square_ten) //second time: no thinking, just result Lazy.force (lazy_square_ten)
- 69. Lazy is a virtue let lazy_square x = lazy ( print_endline “thinking...“ x * x ) let lazy_square_ten = lazy_square 10 //first time: “thinking…” Lazy.force (lazy_square_ten) //second time: no thinking, just result Lazy.force (lazy_square_ten)
- 70. Useful libraries Neat manual Awesome Samples
- 73. “ Empty” source file… 5 pages of help!
- 74. Make sure F# Interactive is running!
- 75. F# Interactive: It’s the bomb!
- 76. F# Interactive:
- 79. 8 Ways to Learn http://cs.hubfs.net Codeplex Fsharp Samples Books ML
- 80. Acknowledgements Cartman Einstein Dilbert Alan Turing Alonzo Church Godzilla Gears of war John Hughes, Why Functional Programming Matters, http://www.math.chalmers.se/~rjmh/Papers/whyfp.html Robert Pickering, Foundations of F#, http://www.apress.com/book/view/1590597575 Slava Akhmechet, Functional Programming For The Rest of Us, http://www.defmacro.org/ramblings/fp.html Steve Yegge, Execution In the Kingdom of Nouns, http://steve-yegge.blogspot.com/2006/03/execution-in-kingdom-of-nouns.html P. J. Landin, The Next 700 Programming Languages http://www.cs.utah.edu/~wilson/compilers/old/papers/p157-landin.pdf Tim Sweeney, The Next Mainstream Programming Language , http://www.st.cs.uni-sb.de/edu/seminare/2005/advanced-fp/docs/sweeny.pdf Tomas Petricek, F# Web Tools, Ajax Made Simple , http://www.codeplex.com/fswebtools Don Syme, http://blogs.msdn.com/dsyme
Editor's Notes
- #2: What’s this F# thing anyway?