catchy phrase for this idiom?

Denis Koroskin 2korden at gmail.com
Thu Mar 12 13:19:07 PDT 2009


On Thu, 12 Mar 2009 23:11:49 +0300, Jarrett Billingsley <jarrett.billingsley at gmail.com> wrote:

> On Thu, Mar 12, 2009 at 9:33 AM, Andrei Alexandrescu
> <SeeWebsiteForEmail at erdani.org> wrote:
>> Hello,
>>
>>
>> I'm looking for a catchy phrase denoting this D idiom:
>>
>> template Blah(Stuff)
>> {
>>   alias ... Blah;
>> }
>>
>> i.e., defining inside a template a symbol of the same name as the  
>> template
>> itself. Then you can use Blah!(X, Y) to mean Blah!(X, Y).Blah.
>>
>> What would be a catchy, descriptive, and memorable phrase for this?
>
> ...Unnecessary?
>
> You know i have to be contrary :P but I have never found a use for
> multiple declarations inside a template _except_ when it's used as a
> mixin.  Most of the time, I declare exactly one symbol inside the
> template, and it's always the same name as the template.  Having to
> specify the name of the template over and over inside it is a blatant
> violation of DRY, easy to mess up (typos, changing the template name
> etc.) and is hard to diagnose when you do it wrong, since the compiler
> just has no idea what you're trying to do and you end up with all
> sorts of confusing errors about voids having no value.
>
> Allowing multiple declarations inside templates looks good in the
> spec, but honestly, I only ever use it for mixins.  My mixin templates
> are also never used as anything other than mixin templates, creating
> this sort of split between templates and mixins, even though they're
> represented by the same language structure.  Mixins are really more
> like a limited form of semihygenic AST macro, one which can only
> expand to declarations and not arbitrary code structures.
>
> If templates were limited to a single declaration - and mixins were
> either changed to a different "type" or replaced outright by macros -
> I'd be perfectly happy, and there'd be no need for Implicit Template
> Name Forwarding (do you see what I just did there ;) ).

Completely agree. That's why I proposed to separate templates and template mixins one from another:
http://www.digitalmars.com/d/archives/digitalmars/D/internal_local_template_memebers_78677.html#N78698



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