Presentation to MindTouch engineers: Intro to FSharp

A Functional Programming Tour using the F# programming language

Transcript

1. INTRO TO F# MindTouch Inc. César López-Natarén
2. WHAT IS F#? Functional and Object Oriented programming language Full support for .NET interoperability Statically typed Support to access other platforms like and through Type Providers Incubated at Microsoft Research, and now a full blown R Matlab open source project
3. ¿QUÉ? Why should I care?
4. CORRECTNESS We need to make sure our business rules are enforced as much as possible by the code Achived through static types, and type inference Concise syntax that avoids boilerplate
5. CONCISE SYNTAX // Creating values let number = 1 // Creating records type User = { Id: int; Name: string } // Type inference let john = { Id = 23; Name = "John D" }
6. GENERICS & TYPE INFERENCE // Type inference & correctness let big a = a > 1000 let bigf a = a > 1000.0 // Lets generalize let bigger a b = a > b let big' a = bigger a 1000 let bigf' a = bigger a 1000.0
7. FUNCTIONAL PROGRAMMING // Type inference let add a b = a + b // Partial application let adder a = add a let add20 = adder 20 // Invocation let twentyOne = add20 1 // Data flow [1 .. 10] |> List.filter (fun n -> n % 2 = 0) |> List.map add20
8. DISCRIMINATED UNIONS // Exhaustive pattern matching type Option<'a> = | Some of 'a | None let printKind something = match something with | Some x -> x.GetType().Name // Null prevention within F# declared types type Person(name : string) = member this.Name = name let printName (p : Person) = printfn "%s" p.Name printName (Person "Haskell Curry") printName null
9. IS IT OVER YET?
10. BENEFITS Being able to change the codebase with agility and confidence Generalized programming Static types without being verbose Using functional programming is easier
11. WTF? “Watch” pane on VS 2012 does not understand how to evaluate F# expressions VS 2012’s F# interactive defaults keybindings differ from Bash defaults Xamarin Studio’s F# interactive does not handle multi-line definitions
12. SKIPPED TOPICS Parallelism constructs Concurrency constructs Lazy sequences Computation Expressions Type providers Code Quotations Active Patterns OO and .NET interoperability
13. RESOURCES FSharp.Org FSharp For Fun And Profit Visual F# FSharp Code Snippets Twitter's #fsharp "F# in the Open Source World" by Don Syme
14. BOOKS by Don Syme et al. by Chris Smith by Tomas Petricek with Jon Skeet by Tomas Petricek and Phillip Trelford Expert F# 3.0 Programming F# 3.0 Real World Functional Programming F# Deep Dives
15. THANK YOU