Ok, I also forgot to tell my own opinion. If you as something for itâs model (or some other thing), you get it. Now itâs up to you if you want to modify it or not. The idea behind encapsulation rules is that you donât force someone to rely on your internal data. So to allow someone add thing to your list you implement #add: method that takes one item and adds it to internal collection. But this doesnât mean that you lock that collection from being modified when you return it. If someone wantâs to write bad code he will do it anyway. One thing that you shouldnât do is to enforce bad practices. But this question was really to gain knowledge from experienced computer scientists/engineers. Cheers Uko On 13 May 2014, at 15:47, David Astels <dastels@icloud.com> wrote:
Well, an issue of good OO design or not. Returning a mutable collection breaks encapsulation. My initial question is whether the collection is simply a detail of the implementation or part of the external interface you want to expose. If the former, hide the collection and expose operations that provide whatâs truly needed. If the latter, then you might need immutable collections.
Java devs arenât crazy⦠they just tend not to understand OO very well.
Dave
On May 13, 2014, at 8:28 AM, Esteban A. Maringolo <emaringolo@gmail.com> wrote:
I think it is more an issue of design.
If your Invoice has a collection of "Items", you shouldn't manipulate the collection directly and instead use accessor/operator methods.
I wouldn't restrict having the option of direct manipulation of the collection, but it is a nice thing to have covered by some LINT rules. :)
Regards,
Esteban A. Maringolo
2014-05-13 6:53 GMT-03:00 Yuriy Tymchuk <yuriy.tymchuk@me.com>:
Hi,
sorry if there was already this question, but I couldnât find it anywhere.
Iâm looking in the OO-design concerns and it seams that Java guys are crazy about returning the collection that is used for state of an objects. The only acceptable option is returning it in the immutable wrapper. As far as I know, pharo does not have immutable collections (except from intervals and symbols). Are we missing something important, or there is a philosophy behind the building blocks we have now, and the design we come up while using them.
Cheers. Uko