#include C headers in D code

[Atila Neves]

On Monday, 9 April 2018 at 18:15:33 UTC, kinke wrote:
> On Monday, 9 April 2018 at 11:03:48 UTC, Atila Neves wrote:
>> Here's my blog post about my project that allows directly 
>> #including C headers in D*
>>
>> https://atilanevesoncode.wordpress.com/2018/04/09/include-c-headers-in-d-code/
>
> Certainly interesting. Is there a good reason why you didn't 
> look into Calypso though? It's restricted to LDC, okay, but its 
> approach of fusioning C++ and D parts at the AST and LLVM-IR 
> level seems far more promising to me - no need to translate the 
> C(++) parts to D and let the underlying D compiler parse & 
> analyze all that generated code again. And Calypso's C++ 
> support is apparently mature enough to interface with Qt5 (!)...

This whole idea came about because a couple of years ago I was in 
a team that was responsible for legacy code written in C which 
had no tests. To write tests, we needed both to write the tests 
themselves and some fakes/mocks/doubles for the code that we 
depended on - essentially a whole operating system. I wasn't 
going to write that in C, since life is too short for that.

I wanted to write it in D, and even tried running dstep on one of 
the dependency headers we had - to no avail. Manual conversion 
was out of the question - too many headers, all them as coupled 
together as possible. So I sighed and started writing some C++14. 
I hated to admit it, but that mess of headers was only really 
usable from C or C++ (Objective C wasn't in the running). I still 
feel bad I picked C++ over D, but it was the right choice.

Why not Calypso? It's a hard enough task to convince a team of C 
programmers who don't know C++ that C++ was a better choice than 
C. It's a herculean task to convince them of D, a language they 
know even less and that they've never heard about (the first 
question is always "but which companies are using D?").

If you add to all that "No, really, it's ok, there's this project 
that forked one of the compilers. No, it's not the reference 
compiler. There's just this bit of non-standard syntax to learn 
that's neither C nor D", then the chances of convincing any 
"normal" engineer are 0.

C++ got popular because it lowered the barrier of adoption to 0. 
I want that for D.  Because of psychological reasons, I don't 
think Calypso is the way to do it, however much it's succeeded 
technically. And the whole point of dpp is convince the average 
coder and their managers.