Functional SC: Introduction to F#

Introduction to F#

July 19th, 2016 extremely technical, Fsharp

With a pre-recorded presentation, we explore the unique features that F# offers to functional developers: functions, composition, piping, discriminated unions, active patterns and computation expressions.

Followup and Q&A is by domain expert Andre Dublin who elaborates on the details and demonstrates the F# IDE's type discrimination features.

This presentation is technical and intended for developers and students.

presentation example code:

let add a b = a + b
let increment = add 1

// infers that a and b are ints
let f a b = a + b

// auto generalization because a and b are generic and must implement the comparision interface
let max a b = if a > b then a else b
max 1 2
max "A" "B"
let makeTuple a b = (a, b)

type PersonA = {
    Name : string
    Age : int
}

let person = {
  Name = "Andre"
  Age = 35
}

//type PersonB = {
//  Name : string
//  Age : int
//}

let updatePersonAge person =
  { person with Age = 35 }

let updatePersonName person =
  { person with Name = "Andre Dublin" }

//let newPerson = updatePersonAge person 36
//let newPersonB = updatePersonName newPerson "Andre Dublin"

// super simple example of function composition
let updatePerson = updatePersonAge >> updatePersonName
let newPerson = updatePerson person

// using an either monad to represent good or bad state
// see http://fsharpforfunandprofit.com/rop/
// see https://github.com/fsprojects/Chessie
// see https://github.com/swlaschin/Railway-Oriented-Programming-Example
type Result<'TEntity> =
  | Success of 'TEntity
  | Failure of string