DIP26: properties defined

[Dmitry Olshansky]

09-Feb-2013 07:13, Michel Fortin пишет:
> On 2013-02-08 23:53:30 +0000, Robert <jfanatiker at gmx.at> said:
>
>> Ok. Here finally it is:
>>
>> http://wiki.dlang.org/DIP26
>
> This is pretty much exactly how I think properties should work. There's
> two possible benefits you may to have overlooked…
>
> One benefit of the "@property T foo;" syntax that does the boilerplate
> code for you over using a plain variable: the getter and setter
> generated are virtual in a class, so a derived class can override them.
> Doesn't work with a plain variable.
>
> Another possible benefit that we could have is the ability to use the
> default getter but to provide your own setter implementation by just
> declaring it:
>
>      @property int a;
>      @property void a(int value) { __a = value; refresh(); }
>

Yes, I too had thoughts along the same lines.

Though just writing some setters by hand and then adding:

mixin TrivialProperties!(_a, _b, _c);

should be doable. But it would be still an ugly boilerplate.

> Much cleaner than this:
>
>      private int _a;
>      @property int a() { return _a; }
>      @property void a(int value) { _a = value; refresh(); }
>
> It's really great to not have to write boilerplate functions when
> default behaviour is perfectly fine. I've been using Objective-C for a
> while now and the recent changes where it automatically synthesize a
> variable, a getter, and a setter when declaring a property (unless you
> provide your own) are truly delightful.
>


-- 
Dmitry Olshansky