SassMeister-input.scss

// ----
// Sass (v3.3.7)
// Compass (v1.0.0.alpha.18)
// ----

// Prototypal inheritance in Sass
// Disclaimer: might be totally contrived and useless...
// “It’s not about the destination, but the journey.”

// New operator
// Creates an instance of an objet that has a constructor function.
@function new($constructor, $args...) {
  @if function-exists($constructor) {
    @return call($constructor, $args...);
  }
  @return ();
}

// Get the prototype of `$object`.
@function prototype($object) {
  @return map-get($object, __proto__);
}

// Set the prototype of `$object`.
@function setPrototypeOf($object, $constructor, $args...) {
  $callee: new($constructor, $args...);

  $prototype: (
    __proto__: map-merge(
      (constructor: $constructor),
      $callee
  ));
  
  @return map-merge(map-merge($object, $prototype), $callee);
}

// Test whether `$prototype` is prototype of `$object`.
@function isPrototypeOf($prototype, $object) {
  @return $prototype == map-get(prototype($object), constructor);
}

// Get property `$property` of `$object`.
@function property($object, $property) {
  @return map-get(map-remove($object, methods), $property);
}

// Test whether `$property` is a direct property of `$object`.
@function hasOwnProperty($property, $object) {
  @return map-has-key($object, $property)
          and not 
          map-has-key(map-get($object, __proto__), $property);
}

// Call method `$method` of `$object`.
@function method($object, $method) {
  $args: ();
  $props: map-get(map-get($object, methods), $method);
  
  @each $prop in $props {
    $args: append($args, property($object, $prop), comma);
  }
  
  @return call($method, $args...);
}



// A constructor.
@function Person($name) {
  $this: (
    kind: "person",
    name: $name
  );
  
  @return $this;
}

// A new object with `Person` as prototype.
@function Employee($name, $title) {
  $this: (
    title: $title,
    methods: (
      greet: (name, title),
      foo: ()
    )
  );
  
  $this: setPrototypeOf($this, Person, $name);
  
  @return $this;
}

// A method.
@function greet($name, $title) {
  @return "Hi I'm #{$name}, working as a #{$title}";
}



// Test
Sass {
  $zack: new(Employee, "zack", "developer");
  
  zack: inspect($zack);
  
  isPrototypeOf_Person: isPrototypeOf(Person, $zack);
  
  hasOwnProperty_kind: hasOwnProperty(kind, $zack);
  
  title: property($zack, title);
  
  greet: method($zack, greet);
  
}

SassMeister-output.css

Sass {
  zack: (title: "developer", methods: ((greet: (name, title), foo: ())), __proto__: ((constructor: Person, kind: "person", name: "zack")), kind: "person", name: "zack");
  isPrototypeOf_Person: true;
  hasOwnProperty_kind: false;
  title: "developer";
  greet: "Hi I'm zack, working as a developer";
}