extern(C++, ns)

[Jason Jeffory via Digitalmars-d]

On Friday, 8 January 2016 at 13:50:56 UTC, Walter Bright wrote:
> On 1/8/2016 12:11 AM, Jacob Carlborg wrote:
>> Walter, should "ns.a()" work in the above example?
>
> No:
>
> 1. first "ns.a" looks up "ns". Finds it in the current module, 
> "main.ns".
> 2. Looks "a" up in "main.ns". "a" is not there. Error.
>
> "a()" works because:
>
> 1. Look up "a" in current module. Doesn't find it.
> 2. Look up "a" in import "foo".
>    1. doesn't find it. Look in imported scope "foo.ns". finds 
> it.
> 3. Look up "a" in import "bar".
>    1. doesn't find it. Look in imported scope "bar.ns". Doesn't 
> find it.
>
> Found only one "a" in the imports. We have da winnah!
>
> I think name lookup rules are straightforward in D. I explain 
> them over and over, for years, and nobody but me understands 
> them. I find it very frustrating.

Lol, that either tells you that you've got it wrong or that your 
just too smart!

How bout this, add compiler functionality where one can 
contribute patches to dmd, and then experimentally use them?

If Manu has such capabilities, he could check his "theory" about 
quite easily(his code would just work)... at leas then everyone 
would know what the real issue is.

As much time that has been wasted arguing over this stuff, the 
feature and fix could have been implemented already.

e.g.,
dmd ... -expermental-nsmodule ....




Not that it matters, my own personal logic tells me that 
namespace resolution should be consistent with D module name 
resolution. To treat all namespaces sort of coming from a global 
chunk of symbols just seems wrong. The whole point in the first 
place was to get around that. Reverting back to C like scope 
resolution for something that was suppose to get away from it 
doesn't make sense logically.

Basically there are two choices,

D Namespaces are module bound(moduleA.ns2 is different than 
moduleB.ns2) or they are not(moduleA.ns2 is the same as 
moduleB.ns2).

How bout this for a solution?

Create a new namespace keyword, _namspace or inline namespace or 
whatever, it behaves one way and the other behaves the other 
way?? This way, everyone wins!!!! Who cares about people that 
"might abuse" something... that's trying to solve a problem that 
doesn't exist yet. If people want to shoot themselves in the 
foot, let them, they will learn, and like everything else, one 
will become deprecated over time, it's nothing new.

It's like trying to prevent people from walking because someone 
once fell in a man-hole. 99.9% of people are good at walking. 
Punish them for the edge case? Maybe the issue is the man hole 
instead?

I imagine it would be easier to write a utility that parses the 
C++ code and does some magic to make it work in D than getting D 
to support something that it already does differently.