This document summarizes Phillip Trelford's presentation on F# on the desktop. It discusses F# user groups in London and testimonials from companies using F# for games, risk management, and software. It also covers desktop programming with F# using UI libraries, data access, visualization, and type providers. Examples are given for spreadsheets, mobile development, and cross-platform frameworks. Resources for learning F# are provided at the end.

1. F# ON THE DESKTOP
Phillip Trelford
Birmingham FP Meetup,
2015

2. F#UNCTIONAL LONDONERS
Founded Feb 2010
990+ Members
Meets every 2 weeks
Topics include
 Machine Learning
 Finance
 Games
 Web
http://meetup.com/fsharplondon

3. F#
Statically Typed
Functional First
Object Oriented
Open Source
Cross Platform
.Net language
In Xamarin & Visual Studio

4. TESTIMONIALS
Phillip Trelford
Birmingham FP Meetup,
2015

5. GAMESYS
..our social slots games which by now serve
over 700,000 unique playersand 150,000,000
requests per day at peaks of several thousand
requests per second.
The F# solution offers us an order of magnitude
increase in productivity....

6. LONDON ASSET MANAGEMENT
COMPANY
We have set up a complete risk
management system that combines
several data sources, presents them in a
… WPF user interface, and does a LOT of
calculation behind the scenes.
When the calculation requires a proper
algorithm (i.e. anything that is more
complex than a simple for loop), our
choice has been F#.

7. HALO 3 & 4
Halo 3 – Matchmaking Halo 4 – Dispatcher frontend

8. DESKTOP
Phillip Trelford
Birmingham FP Meetup,
2015

9. DESKTOPS

10. UI LIBRARIES
Native
XAML (WPF, Windows Store)
WinForms
DirectX (MonoGame, SharpDX,
etc.)
Excel (ExcelDNA, FCell)
Browser
ASP.Net MVC
Suave
NancyFX
WebSharper/FunScript (F# to JS)
.. or host your Web app as a Native app via
Node.js…

11. ANATOMY OF A DESKTOP APP
Data extraction
 Database / Web services
 Configuration files
Data manipulation
 Domain models
 Business rules
Visualization
 Forms/Grids
 Charts

12. F# DATA
Phillip Trelford
Birmingham FP Meetup,
2015

13. TYPE PROVIDERS: JSON
open FSharp.Data
type Person = JsonProvider<""" { "name":"Name", "age":64 } """>
let thomas = Person.Parse(""" { "name":"Thomas", "age":12 } """)
person.Age

14. SQL TYPE PROVIDER

15. WORLD BANK DATA WITH
FUNSCRIPT

16. GRIDS, FORMS & BUTTONS
Phillip Trelford
Birmingham FP Meetup,
2015

17. WINFORMS
open System.IO
open System.Windows.Forms
[<System.STAThread>]
do let form = new Form()
let grid = new DataGridView()
grid.Dock <- DockStyle.Fill
form.Controls.Add(grid)
form.Load.Add(fun _ ->
let files = Directory.GetFiles(".")
grid.DataSource <- [|for file in files -> FileInfo(file)|]
)
Application.Run(form)

18. XAML/WPF

19. F# FOR SPREADSHEETS
Phillip Trelford
Birmingham FP Meetup,
2015

20. FCELL = F# IN EXCEL

21. CELLZ: UNITS IN CELLS
type formula =
| Neg of formula
| Exp of formula * formula
| ArithmeticOp of
formula * arithmetic * formula
| LogicalOp of
formula * logical * formula
| Num of UnitValue
| Ref of int * int
| Range of int * int * int * int
| Fun of string * formula list

22. CROSS PLATFORM F#

23. MONO XWT
Windows + WPF
Windows + Gtk
Linux + Gtk
Mac + Gtk
Mac + Cocoa

24. MOBILE
Xamarin Studio
 iOS
 Android
 Windows mobile
JS
 PhoneGap
 Apache Cordova

25. EXAMPLE APPS
Learn on the Go | WP Pissed off Owls| iOS Pool | WebGL

26. http://tinyurl.com/funbasi
c
FUN BASIC - WINDOWS
STORE APP

27. RESOURCES
Phillip Trelford
Birmingham FP Meetup,
2015

28. F# Software
Foundation
http://www.fsharp.org
software stacks
trainings teaching F# user groups snippets
mac and linux cross-platform books and
tutorials
F# community open-source
MonoDevelop
contributions research support
consultancy mailing list

29. F# KOANS
//---------------------------------------------------------------
// About Let
//
// The let keyword is one of the most fundamental parts of F#.
// You'll use it in almost every line of F# code you write, so
// let's get to know it well! (no pun intended)
//---------------------------------------------------------------
[<Koan(Sort = 2)>]
module ``about let`` =
[<Koan>]
let LetBindsANameToAValue() =
let x = 50
AssertEquality x __

30. TRYFSHARP.ORG

31. BUY THE BOOK

32. QUESTIONS?
Twitter
 @ptrelford
Blog
 http://trelford.com/blog
F# Koans:
 http://tinyurl.com/fsharpkoans