The CAPI Manifesto

[Timon Gehr]

On 10/22/2011 04:33 AM, Walter Bright wrote:
> On 10/21/2011 4:32 PM, Fawzi Mohamed wrote:
>>
>> On Oct 21, 2011, at 4:20 PM, Fawzi Mohamed wrote:
>>
>>> The main problem with this approach is how to support different
>>> versions of
>>> a library, or of OS. It quickly becomes difficult to support anything
>>> but
>>> the latest, or a fixed version. It works beautifully for mature libs.
>
> Since github has excellent support for branches, I don't see why this is
> a major problem.
>
>
>>> I still cannot avoid thinking that a C frontend automatically
>>> generating D
>>> modules with the help of recipes would be a better way. It will need
>>> some
>>> manual intervention for "difficult" cases, mainly giving manual
>>> translation
>>> of some macros, but it should be small.
>>
>> … and it seems that in the time I was offline others came up with the
>> same
>> idea...
>
> It's an old idea. The trouble is, as always, the C preprocessor. I'm
> currently converting the openssl .h files, and they are a zoo of
> metaprogramming using C preprocessor macros.
>
> People are going to demand perfect translation if it is automatic.
>
> The only way to do it is to work with the preprocessed output of the .h
> file, and just forget about the preprocessor.

Another way is to replace the preprocessor with CTFE and string mixins. 
I think that could be automated quite easily. (modulo the possibility of 
some extremely heavy abuse on the C side that could make the other parts 
of the translation a lot harder of course)