type OrderSide =
| Buy
| Sell
type OrderType =
| Market
| Limit
type Order (side:OrderSide, type:OrderType, p:float) =
// Members
member this.Type = type
member this.Price = price
// Properties
let mutable _side = side
member this.Side
with get() = _side
and set(side) = _side <- side
// Functions
member this.toogleOrderSide() = _side <- this.toogleOrderSide _side
member private this.toogleOrderSide (side:OrderSide) =
match _side with
| Buy -> Sell
| Sell -> Buy
// Operator overloading
static member (~-) (order:Order) =
Order(order.toogleOrderSide(order.Side), order.Type, order.Price)
// create instance
let order = Order(Buy, Limit, 45.50)
module Animals
[<AbstractClass>]
type Animal (name: string) =
member this.Name
with get() = name
type Giraffe (name) =
inherit Animal(name)
type Wolf (name) =
inherit Animal(name)
type IAnimal =
abstract member Name : string
with get
type Giraffe (name) =
interface IAnimal with
member this.Name
with get() = name
type Wolf (name) =
interface IAnimal with
member this.Name
with get() = name
let animal = giraffe :> Animal
let downcastGetName (animal : Animal) =
match animal with
| :? Giraffe as giraffe -> giraffe.Name
| :? Wolf as wolf -> wolf.Name
| _ -> String.Empty
