Re: Nontrivial examples of C interface with Ada

[Julian Day <julianday.spam@trap.geocities.com>]

Julian Day wrote:

> I hit on a similar issue a couple of years ago and 'dreamed' up what I
> thought was quite a cute situation at the time.

Oops, that should be solution, not situation...

>
>
> pacakge Ada.Text_IO.C_Interface is
>     type File_Descriptor_Type is new Interfaces.C.Int;    -- or similar
>     function Associate (FD : File_Descriptor_Type) return
>        Ada.Text_IO.File_Type;
> end Ada.Text_IO.C_Interface;
>
> Since this is a child of Ada.Text_IO, it can fill out an appropriate
> File_Type, and 'regular' Text_IO will then just work!
>

(Before I get torn apart)

I think there were two fundemental problems as I remember.

    1. On the compiler I was using, the implementation of File_Type had been
hidden in Text_IO using

private
    type XXX;    -- I can't remember the name.
    type File_Type is access XXX;

    2. I did not have the body of Ada.Text_IO, to have a look at the
implementation of XXX on the compiler I was using.

Julian