SteveGilham

type OptionBuilder() =
    member self.Bind(input, operation) = Option.bind operation input
    member self.Delay (operation:(unit -> 'a option)) = operation ()
    member self.Return input = Some input
    member self.ReturnFrom (input : 'a option) = input
let option = OptionBuilder();;

SteveGilham

let result = option {
let! y = f x
let! z = g y
return! h z};;

SteveGilham

builder {let! pattern = expr
                        compound_expr }

SteveGilham

builder.Bind(expr, (fun pattern -> compound_expr))

SteveGilham

let ReturnAsync x = async { return x }
let (>>=!) m f = async { return Async.RunSynchronously(f(Async.RunSynchronously m)) }
let (>>!) m1 m2 = m1 >>=! fun () -> m2
let (>=>!) f g = fun x -> ((f x) >>=! g)
let ApplyAsync m1 m2 =
      m1 >>=! fun f ->
      m2 >>=! fun x ->
      ReturnAsync (f x)
let LiftAsync f = ApplyAsync (ReturnAsync f)
let SequenceAsync (l : _ list) =

SteveGilham

let Half_Adder x y = (XOR x y, AND x y);;

SteveGilham

let fst (a,b) = a;;
let snd (a,b) = b;;

SteveGilham

type  Point = { x: int; y: int; move: Point -> Point }
let rec makePoint vx vy = 
    let doMove p = makePoint (vx + p.x) (vy + p.y)
    { x = vx; y = vy; move = doMove };;

SteveGilham

let p = (makePoint 1 2).move(makePoint 2 3);; 

SteveGilham

{p with x = 6; y = 0 };;