I have following code:
class Circle
constructor: (@center, @radius, @color) ->
@Red: (@center, @radius) ->
new @ center, radius, 'red'
class Point
constructor: (@x, @y) ->
I can create red circle like this: red_circle = Circle.Red(new Point(0,0), 10)
But following code doesn't work:
obj = Circle.Red
red_circle = obj(new Point(0,0), 10)
What am I doing wrong?
Circle.Red(...) sets this (@) to Circle; so new @ = new Circle.
obj(...) does not set this, so new @ is invoking new on something else (depending on the context).
You can fix this by binding: obj = Circle.Red.bind(Circle)
When invoked as obj(), there's no context to the call; meaning this inside the function is not Circle, but rather likely window. You need to bind the context to preserve it:
obj = Circle.Red.bind Circle
