Re: Variant records..

[ganesh.ramasivan@gdcanada.com (Ganesh Ramasivan)]

Preben Randhol <randhol+valid_for_reply_from_news@pvv.org> wrote in message news:<slrnc318ga.3ja.randhol+valid_for_reply_from_news@k-083152.nt.ntnu.no>...
> On 2004-02-15, Ganesh Ramasivan <ganesh.ramasivan@gdcanada.com> wrote:
> > In the following example, how would i forbid the user of data type Foo
> > from specifying the following:
> >
> > John : Foo(Vehicle => MAN, Power => AUTOMATIC);
> >
> > ie. is there a way to restrict the user from specifying certain types
> > as variants?
> 
> I guess this is homework? If it is why don't you simply try to do this
> and see what happens?

Okay.. I should probably have been a bit more realistic.. I am new to
ada but this is no homework assignment.

type RADAR_TYPE_CHOICE is (RADAR_A, RADAR_B, RADAR_C);
    
type RADAR_A_COMMAND_CHOICE is (RADAR_A_STATE,
                                RADAR_A_MODE,
                                RADAR_A_DISPLAY_RANGE_SELECT);
                                      
type RADAR_B_COMMAND_CHOICE is (RADAR_B_STATE,
                                RADAR_B_MODE,
                                RADAR_B_DISPLAY_RANGE_SELECT);

type RADAR_C_COMMAND_CHOICE is (RADAR_C_STATE,
                                RADAR_C_MODE,
                                RADAR_C_DISPLAY_RANGE_SELECT);

type RADAR_CHOICE(RADAR_TYPE : RADAR_TYPE_CHOICE :=
RADAR_TYPE_CHOICE'FIRST) is
      record   
        case RADAR_TYPE is
    	  when  RADAR_A =>
            null;
    	  when  RADAR_B  =>
            null;
    	  when  RADAR_C =>
            null;            
        end case;
      end record;

How would I specify a variant record which will only allow me to
select RADAR_A for the RADAR_TYPE_CHOICE and RADAR_A_STATE for the
command choice but not RADAR_C_STATE?