// Object consists of zero or more
// slots and optionally code
type Objekt =
  { mutable Code : Objekt option
    mutable Slots : Slot list }

// A slot has name and contents;
// Some slots are parents
and Slot =
  { Name : string
    Contents : Objekt
    IsParent : bool }

"""Data object with name"""
(| book = 'Alice in Wonderland' |)

"""Method with  some code"""
( self name printLine )

"""Data object with parent
 slot and a 'speak' method"""
(| parent* = cat
   name = 'Cheshire Cat'
   speak = (
     self sound printLine
   )
|)

"""Data access or method call"""
cheshire name
cheshire speak

type Person =
  { mutable Name : string
    mutable Book : string option }

let setName n p =
  p.Name <- n
let setBook b p =
  p.Book <- Some b

let x = { Name = "Bill"; k = None }
x |> setName "William"
x |> setBook "Alice in Wonderland"

match x with
| { Book = Some book } ->
  printfn "%s likes %s" x.Name book
| _ ->
  printfn "%s is sad :-(" x.Name