In F#, delegates are reference types. It allows us to call the function as an object. It is a feature of this language. It gives an advantage over the other functional programming languages.
type Deligate() =
static member mul(a : int, b : int) = a * b
member x.Mul(a : int, b : int) = a * b
type Multiply = delegate of (int * int) -> int
let getIt (d : Multiply) (a : int) (b: int) =
d.Invoke(a, b)
let d : Multiply = new Multiply( Deligate.mul )
for (a, b) in [(5, 8) ] do
printfn "%d * %d = %d" a b (getIt d a b)
