Classes: Dak Tour

; Classes are less special in Dak than in JavaScript.

; Declarations look like:
(class Animal)

; Extends can be used for inheritance:
(class Dinosaur :extends Animal)

; Expressions look like:
(const TRex (class :extends Dinosaur))

; Instances are created using the constructor
; with a dot (.) suffix:
(const pet (TRex.))

; instanceof, or the alias isa? can be used like:
(prn "instanceof TRex =" (instanceof pet TRex))
(prn "isa? Dinosaur =" (isa? pet Dinosaur))

; Classes support using let and the fn family of builtins
; to define properties and methods.
(class Stego :extends Animal
  (let #name)

; Constructor functions are defined like a regular function.
  (fn constructor [name]
    (super)

; Private variables are automatically prefixed with this.
    (set #name name)

; An explicit return is required since otherwise the (set)
    ; above is used as the return value.
    (return))

; Async functions, as well as generators are supported.
  (fn@ greet []
    (prn #name "says hello.")))
@(.greet (Stego. "Barney"))