Re: Return unconstrained types in ZFP

["Rego, P." <pvrego@gmail.com>]

> Another alternative is to use a procedure:
>       procedure Get 
>          (Port      : in USART_Port_Type; 
>           Data      :    out String_U8; 
>           Data_Last :    out Unsigned_8);
> Then the user must allocate space for Data:
> declare
>    Data      : String_U8 (1 .. Size);
>    Data_Last : Unsigned_8;
> begin
>    Get (Port, Data, Data_Last);
>    ... use Data
> end;
> This way, you don't need to implement the runtime code.
> It is more of a burden for the user, but that's the point of ZFP; it's
> easier to implement, harder to use.

Stephe, you made a very good suggestion. So I don't need to implement the rt code, at least for now (I'm sure I will miss RAM if I do it now). Thanks!

> Is "Size" a maximum here, or is the result expected to be exactly Size
> bytes long?

At first I would put the Size to set the exact size of the output String_U8, but if the user allocate it first, it fits the idea well. 

So, I used something like

   procedure Get
     (Port : in USART_Port_Type;
      Data : out String_U8);
...
   procedure Get 
     (Port : in USART_Port_Type;
      Data : out String_U8) is
   begin
      for Index in 1 .. Data'Length loop
         Data (Unsigned_8 (Index)) := Get (Port);
      end loop;
   exception
      when others => null; -- no need for this now
   end Get;
 
Thanks again Stephe, Rolf, Luke and Shark8.