Re: Re-Marketing Ada (was "With and use")

[Warren Gay <ve3wwg@cogeco.ca>]

"Chad R. Meiners" wrote:

> "Warren W. Gay VE3WWG" <ve3wwg@cogeco.ca> wrote in message
> news:PPrvb.1623$NB4.26040@news20.bellglobal.com...
>
> > The one problem that I constantly have to hand craft a solution
> > to is the interfacing with C components on different platforms.
> > A value in a C header file for FreeBSD may or may not be the
> > same as the same on a Linux host. That same value (or type
> > size) may differ again on a Linux/Alpha host for another.
>
> Instead of a hint file, perhaps a better reproach would be a to have an api
> specification which declares the types and subroutines that you want to
> appear in the thin binding, and where in the C header file to get there
> definition?  This way you can guarantee the resulting thin binding will have
> a consistent interface despite the changing representations.

OK, I think were on similar wavelengths here. So instead of using
a hints file, specify what you hope to get out of the header file.

Well, I suppose this works very well for the API functions, structures,
types etc. One area where this falls down perhaps is for macro
constants (imagine trying to specify all the error code constants
from something like errno.h). But I suppose you could do the
following:

  - Choose all or nothing folded macro constant definitions
  - Choose all including or all except according to a set of
    regular expressions matching the macro name. For
    example, you could specify:

    Defines include "HAVE_.*"

    to grab those macros out of the MySQL my_config.h file.

Actually, the more I think about your idea, the more I like it. It has the
additional advantage that you only expose yourself to areas that are
important to your application. IOW, there is a much greater chance
of success on all platforms, if you stick to only what you need,
rather than everything and the kitchen sink. I like that idea.

Maybe you should be writing this tool? ;-)

--
Warren W. Gay VE3WWG
http://home.cogeco.ca/~ve3wwg
[Remove the nospam from the email address: blame the worms]