Interface file

[Jan Johansson via Digitalmars-d]

On Wednesday, 30 September 2015 at 19:24:05 UTC, Jeremy DeHaan 
wrote:
> On Wednesday, 30 September 2015 at 17:51:50 UTC, Jan Johansson 
> wrote:
>> [...]
>
>
> Like Adam said, the real difference between a .d and a .di file 
> is that the .di file has all the guts removed and is just the 
> declarations.
>
> If using a .di file is really what you want, you could try 
> something like this?
>
> test.d:
> module test;
>
> interface IMyTest {
>    void Write(string message);
>  }
>
>
>  IMyTest createInstance() {
>     class MyTest : IMyTest {
>      void Write(string message) {
>          import std.stdio;
>          writeln(message);
>      }
>  }
>
>      return new MyTest;
>  }
>
> ---------------
>
> test.di:
>
> module test;
>
> interface IMyTest {
>    void Write(string message);
>  }
>
>
>  IMyTest createInstance();
>
> ---------------
>
> main.d:
>
> import test;
>
> void main() {
>     auto p = createInstance();
>     p.Write("Hello, World!");
> }
> --------------
>
> and then
>
> dmd test.d -lib -oftest
>
> and
>
> dmd main.d test.di test.a
>
>
> Also like Adam said, dmd can create these .di files for you so 
> you don't have to!
>
> (This is untested, but should work/be close to working)

Thanks Jeremy,

Do you spot a weakness in your proposed code snip? The 
declaration for interface is done in two separate files, both 
test.d and test.di. Scattered declarations has never been a good 
idea. I know that I can ask the DMD to do declaration files for 
me, but the use case for that is to speed up building of 
executable.

But is it that the separation of declaration and implementation 
was never the intention in the design of D?

//Jan