Re: Problem with packages

[Stephen Leake <stephen.leake@gsfc.nasa.gov>]

Sean kenny wrote:
> 
> can anyone tell us why this the following code won't compile
> we keep the following error message
> 
>  invalid prefix in selected component "working_hold"
> 
> on the indicated lines
> 
> hold_id is defined in the following package which compiles
> ok.

You've defined Hold_ID as a "limited private" type. This means client
packages (like gang) cannot access any elements of the type directly.

Either make the type not limited, or provide a function in package
foreman that gives you the access you need.

-- Stephe

> 
> WITH foreman;
> use foreman;
> 
> PACKAGE BODY gangs IS
> TASK body gang is
>   hold_state : work := more;
>   working_hold: hold_id;
> begin
>   foreman.request_work(working_hold);
>   WHILE hold_state = more loop
>   working_hold.next_container(hold_state);      <----
>   END loop;
> 
>   working_hold.complete;        <------
> end gang;
> 
> END gangs;
> 
> package foreman is
> 
> type work is (more, finished);
> type hold_id is limited private;
> 
> procedure request_work(this_hold : in out hold_id);
> private
> type hold;
> type hold_id is access hold;
> task type hold is
>  entry next_container(state : out work);
>  entry complete;
> end hold;
> end foreman;--
>