Re: 'Image for composite types

[Georg Bauhaus <rm.dash-bauhaus@futureapps.de>]

Adam Beneschan schrieb:
> On May 27, 3:20 pm, Martin <martin.do...@btopenworld.com> wrote:
>> Is it just me that gets fed up with the lack of 'Image on composite
>> types?
>>
>> I'm thinking in particular of when I'm testing / debugging and usually
>> end up writing lots of 'Put_Line' code for each and every record. And
>> then having to maintain them.


> A lot more thought would have to go into this to make it a real
> language feature.

Maybe a simple standardized package will do, as follows.
Alluding to SNOBOL-4's &TRACE mechanism, Perl's
Data::Dumper, (SML/NJ compiler access in user programs?),
and ASIS:  Since an Ada compiler knows the internal represenation
for every type, it can instantiate a simple tracing procedure.

This assumes that a stupid implementation defined subprogram
is enough for testing / debugging.

package Mypack is

   type T is private;

private

   type T is record
      U: Unbounded_String;
      T: Time;
   end record;

   pragma Convention(ASIS, T);
	-- if it is necessary to annouce this to
	-- the compiler for tracing

end Mypack;



with Compiler; -- a portable/language defined spec
with Mylog;    -- here is where I want the data images

pragma Tracing (On);

package body Mypack is

   procedure Put_T is
      new Compiler.Trace (Data => T,
                          Stream => Mylog.Stderr);

end Mypack;