D/Objective-C, extern (Objective-C)

[Paulo Pinto]

On Monday, 24 June 2013 at 22:39:13 UTC, Steven Schveighoffer 
wrote:
> On Mon, 24 Jun 2013 18:10:19 -0400, bearophile 
> <bearophileHUGS at lycos.com> wrote:
>
>> Jacob Carlborg:
>>
>>> I don't think it adds much complexity. If you don't use 
>>> extern (Objective-C) you don't need to learn it.
>>
>> D books must be bigger, D programmers must read those parts of 
>> the books, the error messages become more complex (because you 
>> can hit by mistake the unwanted syntax, or because the 
>> compiler recovering of errors must consider more 
>> possibilities), the compiler gets a little larger. Thinking 
>> that some new syntax has no costs is very wrong.
>
> I think this is largely false.  In order for the new syntax to 
> be valid, you must use extern(Objective-C).  That would be 
> quite an accident.
>
> Consider that I have never dealt with the COM compatibility (or 
> frankly, even the extern(C++) compatibility) part of D 
> whatsoever.  Because I've never implemented IUnknown, or used 
> extern(C++).
>
> These features that are enabled by specific syntax are not 
> extra complexity for D.
>
> Note that TDPL makes no mention of IUnknown or COM 
> compatibility, yet I have never seen a post on D.learn asking 
> questions about this feature set unless they were actually 
> looking to write COM code.  In other words, no accidental 
> enabling (I have seen questions as to why interfaces are not 
> Objects, and I grudgingly have to point to the incorrect belief 
> that COM objects cannot be discerned from normal D objects at 
> compile time).
>

This will surely change if we ever want to target WinRT with D, 
as it is COM based and might be the future Windows default API in 
the long term.

I am quite curious to see the presentations of this week BUILD 
2012, to see what changes Microsoft might be briging to WinRT.

--
Paulo