Re: GNAT.Serial_Communications

[Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>]

On 04/15/2011 09:32 AM, tonyg wrote:
>        for count in
> 1..Ada.Streams.Stream_Element_Offset(The_String'Length) loop
>           Return_Value(count) :=
> character'pos(The_String(Integer(count)));

You assume that The_String'First = 1, which will not be the case if you pass a 
slice with a different lower bound. However, that will cause Constraint_Error 
(unless you have turned off this check), which does not seem to be the problem.

>        Return Return_Value(1..The_String'Length);

I see no reason for the slice.

You should be able to replace the body of String_To_Stream with a simple 
Unchecked_Conversion:

with Ada.Streams;
with Ada.Text_IO;
with Ada.Unchecked_Conversion;

procedure Stream_Convert is
    subtype String3 is String (1 .. 3);

    From : constant String3 := "abc";

    subtype Stream3 is Ada.Streams.Stream_Element_Array (1 .. From'Length);

    function To_Stream is new Ada.Unchecked_Conversion (Source => String3, 
Target => Stream3);

    To : Stream3;
begin -- Stream_Convert
    To := To_Stream (From);

    Output : for I in To'range loop
       Ada.Text_IO.Put (Item => To (I)'Img);
    end loop Output;
end Stream_Convert;

-- 
Jeff Carter
"Unix and C are the ultimate computer viruses."
Richard Gabriel
99