← Back to context

Comment by zzzcpan

10 years ago

They are not exactly equivalent though. It is not possible to completely abstract away state changes with objects. You always end up with at least two calls that you have to keep track of.

8 comments

zzzcpan

Reply
tel  10 years ago

I'm not sure that I would agree here. Do you have a simple example?

  • zzzcpan  10 years ago 

      foo.DoSomething()
  ... // remember not to return 
      // without foo.Done() called
      // (EDITed for clarity: 
      // foo is the state, that changes,
      // so you have to keep track of 
      // its changes)
  foo.Done()

    vs

      DoSomething (func(){
     ... // don't have to remember 
         // a thing, no side-effects, 
         // equivalent of .Done() is
         // called afterwards for you
  })

    EDIT2: exact behavior is not the point, keeping track of things is.

    • tel  10 years ago

      That doesn't seem to have anything to do with objects versus closures. In both cases the right answers is absolutely to pass a function to DoSomething be it a function or a method.

      If you're considering a language deficient of functions then we can take advantage exactly of the idea that objects can embed functions by having a "callable" thing.

          foo#doSomething (object
      method call : unit -> unit =
        ...
    end)

      1 reply →

    • Sanddancer  10 years ago

      Classes don't need to have mutable state. I've written several rather useful classes that were completely immutable after initialization. As such, there are no things to keep track of. No side-effects, nothing like that, a snapshot in time of whatever values I need to pass elsewhere.