Precompiled libraries in D

[Jacob Carlborg]

On 2012-11-20 22:58, Matthew Caron wrote:
> Apologies if this is a "generic D" question, but I can't find an answer
> in any of the D documentation, and folks on this list are quite helpful.

This is a fairly generic D question which would have fit better in the 
digitalmars.D newsgroup. But I'll answer it here anyway :)

> The precompiled-library-and-header paradigm is very common in C. Is
> there a similar one in D? I've used wxd, which is a port of wxWidgets to
> D, and it builds a static .a library, which gets you half there, but
> there is no equivalent header file that gets included - just the wx.d
> file. Basically, if I'm linking against a D library, from where does the
> user-readable documentation for that library come? Is it incumbent upon
> the provider to provide Doxygen-style documentation?

The precompiled-library-and-header paradigm can be used in D as well. 
It's just not that common. In D there is, what's called, D interface 
files (.di) in stead of header files. You can do any of

* Just use the source together with a pre-compiled library (should 
probably be renamed to .di in that case)
* Manually create di files
* Automatically generate di files with the -H flag (I don't know if GDC 
uses the same flag for this)

Generating documentation from ddoc (similar to Doxygen) comments is 
preferred to do, but not many libraries do that. You can use the -D flag 
to do that, if the library do have ddoc comments.

> (This came out of a lunchtime discussion at work - the statement was
> made that "at least the C headers keep you honest. You can't use it
> without something that a human can read". Not technically true, but the
> point is well taken. While complete source code availability doesn't
> matter for many cases (purely open source or purely internal
> commercial), it does matter when you have a company writing a library to
> be used by a client and they want a binary library + an API definition
> exposed via a header file).
>
> Thanks in advance.

See above.

-- 
/Jacob Carlborg