F# example

type MyUnion =
| First of int
| Second of double

type MyRecord = {
    A: int
    B: double
    C: MyUnion
}

let test (a: MyRecord) (b: int) =
  let c: double = 1.0
  ()

let test a = async {
    return a;
}
let test a = foobar {
    return a;
}

// Mass, grams.
[<Measure>] type g
// Mass, kilograms.
[<Measure>] type kg

[<DllImport("kernel32", SetLastError=true)>]


let func : HttpFunc = handler (Some >> Task.FromResult)

type Base1() =
    abstract member F : unit -> unit
    default u.F() =
        printfn "F Base1"

type Derived1() =
    inherit Base1()
    override u.F() =
        printfn "F Derived1"

let d1 : Derived1 = Derived1()

let base1 = d1 :> Base1
let derived1 = base1 :?> Derived1

type PersonName =
    | FirstOnly of string
    | LastOnly of string
    | FirstLast of string * string

type Shape =
    | Rectangle of height : float * width : float
    | Circle of radius : float

type MyInterface =
   abstract member Add: int -> int -> int
   abstract member Pi : float

exception Error1 of string
exception Error2 of string * int