CS2 Discussion: Features: Getters / Setters

[coffeescriptbot]

From @CliffS on 2017-05-05 09:50

I have been following the discussions on getters/setters and I totally understand and concur with the reasoning behind not allowing the standard ES6 syntax in CS2.

However, the solution given in the draft manual is, IMO, both unclear and against the general philosophy of CS which is to make things less verbose and easier to use. I am constantly pushing CS as a more concise way of writing JS and having to write the following is simply counter-intuitive.

class  screen

  width: 1200
  ratio: 16/9

  Object.defineProperty @, 'height',
    get: ->
      this.width / this.ratio
    set: (val) ->
      this.width = val / this.ratio

What about introducing a new syntax? Something on the lines of:

class screen

  width: 1200
  ratio: 16/9

  |get| width: ->
      this.width / this.ratio
  |set| width: (val) ->
      this.width = val / this.ratio

Thoughts?

[coffeescriptbot]

From @GeoffreyBooth on 2017-05-05 14:21

Getters and setters weren't rejected because we couldn't come up with a workable syntax. They were rejected because it's a language feature that's discouraged. The note in the docs isn't to say "this is how you should do getters and setters in CoffeeScript," it's to say that we discourage them but if you insist you can use them using this verbose syntax.

[coffeescriptbot]

From @joeldrapper on 2017-05-06

@GeoffreyBooth Why are they discouraged?

[coffeescriptbot]

From @GeoffreyBooth on 2017-05-06

See coffeescript6/discuss#17

[coffeescriptbot]

From @joeldrapper on 2017-05-06

Thanks @GeoffreyBooth, I’ll take a look at that thread.

I think they can be implemented quite easily with class methods if people want to use them. Something like this could work.

class BaseObject
  @get: (name, fun) ->
    Object.defineProperty @::, name,
      get: ->
        fun()

  @set: (name, fun) ->
    Object.defineProperty @::, name,
      set: (value) ->
        fun value

Edit: I found a much better way to do this.