On Tue, Dec 2, 2014 at 12:01 PM, Tom Hacohen <tom.haco...@samsung.com> wrote:
> On 29/11/14 00:53, Chris Marshall wrote: > > On Fri, Nov 28, 2014 at 11:01 AM, Tom Hacohen <tom.haco...@samsung.com> > wrote: > >> On 28/11/14 13:36, Chris Marshall wrote: > >>> On Nov 28, 2014 4:12 AM, "Tom Hacohen" <tom.haco...@samsung.com> > wrote: > >>>> > >>>> On 28/11/14 10:05, Tom Hacohen wrote: > >>>>> On 25/11/14 21:58, Chris Marshall wrote: > >>>>>> I would like to support perl5 roles which are also known as traits: > >>>>>> > >>>>>> http://scg.unibe.ch/archive/papers/Scha03aTraits.pdf > >>>>>> > >>>>>> >From the positive experience with roles in perl5 modern OO > >>>>>> developments, there is reason to believe that their support in > >>>>>> EO might be equally useful and maybe an improvement over > >>>>>> the mixin functionality. > >>>>>> > >>>>> > >>>>> Thanks, will read into that. > >>>>> > >>>>> Will reply to the rest of your emails in a second. > >>>> > >>>> I don't see how they are different from mixins with 0 associated data. > >>>> They just seem like a more restricted version of mixins. > >>> > >>> The main difference is that they get composed into the class as they > are > >>> applied so there is no further MRO or inheritance. This gives the good > >>> parts of multiple inheritance without the pathologies. > >> > >> OK, so they are a way to add methods to a class directly? Interesting. > >> Though I don't see the benefits over mixins. They integrate well into > >> the MRO and let you do a bit more (have data) that we actually use > >> (though could refactor to avoid). > > > > Here are a couple of pages that give some explanation > > of roles in perl5 and the comparison of roles versus > > interfaces, mixins, and traits in some other languages. > > > > http://search.cpan.org/~ether/Moose-2.1402/lib/Moose/Manual/Roles.pod > > > http://radar.oreilly.com/2014/01/horizontal-reuse-an-alternative-to-inheritance.html > > > > For the purposes of the Perl Data Language, the use of > > roles, method modifiers (before, around, after other methods), > > together with the ability to apply roles to objects form the > > basis for the PDL3 JIT support in the works. > > > > I skimmed over the links, and I still don't see the benefit. A mixin > could provide the pull_plough without any issues, and everything will > work as expected. > Furthermore, in the first link it's explicitly said that "Moose roles > are similar to mixins or interfaces in other languages.", so even there > they don't say anything about them being better. > > I need an example (preferably a real life use case) of something I can't > do, or can it's much harder to do, without roles. > > Understood. Once I can get eo/eina/eolian working I plan to determine where on the spectrum perl "roles" fit relative to the EO "interfaces" and "mixins". From what I can tell, there is a bit of variation in exactly what is meant and how the implementations work. If I can accomplish my goals withEO mixins as-is, great. If I determine that something more is needed for my PDL application, I'll provide some use cases supporting that need and investigate options for implementation. It would probably amount to a new enum for roles and code to handle them. I spent a number of hours on Saturday working to edit out the non-eo/eina/eolian parts of the src/Makefile.am and the configure.ac but when I was getting close, I deleted one too many things and ended up with a configure file that would not execute so I'm back to square one on that. --Chris ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
