[webkit-dev] Pattern for singleton classes instance getters

Filip Pizlo fpizlo at apple.com
Wed Jan 28 20:46:19 PST 2015

> On Jan 28, 2015, at 8:44 PM, Michael Catanzaro <mcatanzaro at igalia.com> wrote:
> On Wed, Jan 28, 2015 at 8:11 PM, Maciej Stachowiak <mjs at apple.com> wrote:
>> Yet another possibility is finding a better name than ‘shared’ for the singleton pattern function, but I don’t have any better ideas. Class::getSingleton() is more explicit but the extra verbosity doesn’t seem helpful to me.
> I recommend Class::instance(), which is what I've seen used almost exclusively outside of WebKit. It's what Scott Meyers used, and it's very similar to the Gang of Four's choice of Class::Instance() and the Java pattern Class.INSTANCE.

I've seen this, also.  It's a good name.

> That said, Class::singleton() is very attractive too.


> I've never seen Class::shared() used anywhere except WebKit. The first time I saw this I had no clue what it was until I looked up the implementation.


> All of these can get quite annoying to type, especially when the name of the class is long. (Sometimes I will keep a reference to the instance in a local variable with a shorter name.) But I think they're easier to read than free functions, and we should optimize for reading code, not writing it. Not a big deal either way.
> _______________________________________________
> webkit-dev mailing list
> webkit-dev at lists.webkit.org
> https://lists.webkit.org/mailman/listinfo/webkit-dev

More information about the webkit-dev mailing list