Re: Generic child units with Gnat

[dweller@Starbase.NeoSoft.COM (David Weller)]

In article <3l5q2n$6le@unix.sbu.ac.uk>,
Fintan Culwin  <fintan@sbu.ac.uk> wrote:
>[supplied source deleted]
>Where is the library level ??
>What have I got wrong ??
>How does one instantiate generic children in gnat??
>help !!
>
>Private e-mail preferred & I will sumarise later ...
>
I'm posting publicly, since I think a lot of folks would like to know
this (and to prevent your mailbox from getting flooded... :-)

There were only two small problems:
1) generic package instantiations go inside that package declaration,
not before
2) Your child instantion syntax was a little off
3) your filenaming convention was slightly off (to my knowledge, GNAT
still requires a specific manner to naming child units)

(*Ahem*  I'm sure Norm Cohen will point out that I now qualify as the other
half of those "three types of people" :-)

Instead of going into gory details, I'm posting the corrected source
below.  It was pretty easy to fix.

-- File: complexnumbers.ads
generic
   type FloatType is digits <>;
package ComplexNumbers is
   procedure foo( Dummy : in FloatType);
end ComplexNumbers;

--File: complexnumbers.adb
package body ComplexNumbers is
   procedure foo( Dummy : in FloatType) is
   begin -- foo
      null;
   end foo;
end ComplexNumbers;

--File: complexnumbers-polar.ads
generic
package ComplexNumbers.Polar is
   procedure bar( Dummy : in FloatType);
end ComplexNumbers.Polar;

--File: complexnumbers-polar.adb
package body ComplexNumbers.Polar is
   procedure bar( Dummy : in FloatType) is
   begin -- bar
      null;
   end bar;
end ComplexNumbers.Polar;

--Filename foobar.adb
with ComplexNumbers.Polar; -- auto visibility to parent
procedure FooBar is
   package RealComplexNumbers is new ComplexNumbers( Float);
   package PolarRealComplexNumbers is new RealComplexNumbers.Polar;
begin -- FooBar
  null;
end FooBar;


-- 
      Frustrated with C, C++, Pascal, Fortran?  Ada95 _might_ be for you!
	  For all sorts of interesting Ada95 tidbits, run the command:
"finger dweller@starbase.neosoft.com | more" (or e-mail with "finger" as subj.)
		if u cn rd ths, u r gd enuf to chg to Ada   :-)