dsshep

// In F# if we have a record and instance:
type RecordOne = {
      PropOne: string
      PropTwo: int
}

let recordOne = { PropOne = "PropOne"; PropTwo = 1 }

// it can then be updated as so:

dsshep

module Age = 
    type Age = private Age of int

    let create (age : int) : Age option = 
        if age < 0 then None else Some (Age age)

module Application = 

    let invalidAge = Age.create -1 // none
    let validAge = Age.create 10 // some