Re: Closure for object pattern? A good idea?

Very clear thank you ! I can't wait to know these concept as I am discovering clojure with the 'Functionnal programming for OO programmer' book. Thank you again Le samedi 17 décembre 2016 18:53:31 UTC-5, James Reeves a écrit : > > On 17 December 2016 at 22:13, Rafo Ufoun

Re: Closure for object pattern? A good idea?

On 17 December 2016 at 22:13, Rafo Ufoun wrote: > I'm a real newbe to clojure and functionnal programming but reading your > answer raised a question : > > Where do you "store" the stopwatch object which you are passing to all > your functions ? > > I understand that

Re: Closure for object pattern? A good idea?

On Dec 10, 2016 1:47 AM, "Didier" wrote: I'm wondering what everyone thinks of using closures to mimic a simplistic object system in Clojure? I'm not sure what to think of it yet, but the idea is that you wrap object fields inside a closed function, and it returns a map of

Re: Closure for object pattern? A good idea?

I'm a real newbe to clojure and functionnal programming but reading your answer raised a question : Where do you "store" the stopwatch object which you are passing to all your functions ? I understand that mutability is not needed to develop the functions you described but all of them take

Re: Closure for object pattern? A good idea?

Let me add a couple of comments, both from a clojure perspective and from other languages. First, I have used this pattern in clojure and similar languages. I find it is often useful when I need to deal with multiple functions mutating the same state. In clojure, I used this to make little

Re: Closure for object pattern? A good idea?

Logan's point about being able to add new functions on a stopwatch is valid. That's often the argument to why protocols are better then classic OO. Though I still feel like in some scenarios, I think this is a good pattern, and can serve us better, the stopwatch being one good example. Nothing

Re: Closure for object pattern? A good idea?

You don't need mutability to represent a stopwatch. (defn start [stopwatch] (assoc stopwatch ::start-time (System/currentTimeMillis))) (defn elapsed-since-started [stopwatch] (- (System/currentTimeMillis) (::start-time stopwatch))) (defn stop [stopwatch] (-> stopwatch

Re: Closure for object pattern? A good idea?

I feel like you would be better off separating functions from the data they operate on here. In this case, you could represent the state of a stopwatch with a map containing the start time and the time elapsed, and have functions `stop`, `reset`, `start`, etc that take the stopwatch data

Closure for object pattern? A good idea?

I'm wondering what everyone thinks of using closures to mimic a simplistic object system in Clojure? I'm not sure what to think of it yet, but the idea is that you wrap object fields inside a closed function, and it returns a map of methods that operates over those fields. Here's an example of