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From: Stephen Leake on 20 Apr 2010 03:25
tonyg <tonythegair(a)googlemail.com> writes:

> I have some data coming in from a serial port which I want to convert
> to hexadecimal and display on the screen. I was wondering if anyone
> knows of a simple way to do this?

Just to chime in with my generic solution to this (from SAL
http://www.stephe-leake.org/ada/sal.html) :

pragma License (Modified_GPL);

generic
Width : Natural;
type Number_Type is mod <>;
function SAL.Generic_Hex_Image (Item : in Number_Type) return String;
-- Return a hexadecimal image of Item, padded with leading zeros to
-- Width. If Width is too small for Item, leading digits are silently
-- truncated.
pragma Pure (SAL.Generic_Hex_Image);

function SAL.Generic_Hex_Image (Item : in Number_Type) return String
is
Temp : Number_Type := Item;
Nibble : Number_Type;
Image : String (1 .. Width);
begin
for I in reverse Image'Range loop
Nibble := Temp mod 16;
Temp := Temp / 16;
if Nibble > 9 then
Image (I) := Character'Val (Character'Pos ('A') + Integer (Nibble) - 10);
else
Image (I) := Character'Val (Character'Pos ('0') + Integer (Nibble));
end if;
end loop;
return Image;
end SAL.Generic_Hex_Image;

--
-- Stephe
From: tonyg on 20 Apr 2010 05:00
On Apr 19, 9:50 pm, Ludovic Brenta <ludo...(a)ludovic-brenta.org> wrote:
> tonyg writes on comp.lang.ada:
>
> > Changed the hex function to
> > function To_Hex (E : in Ada.Streams.Stream_Element) return String
> > is
> >    -- Warning: not compiled and not tested...
> >    X : constant array (0 .. 15) of Character :=
>
> (1) I should have written:
>
>     X : constant array (Ada.Streams.Stream_Element range 0 .. 15) of Character :=
>
> >      ('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
> >       'C', 'D', 'E', 'F');
> >    Result : String (1 .. Ada.Streams.Stream_Element'Size / 4); -- 1 hex digits = 4 bits
> >    Working_Copy : Ada.Streams.Stream_Element := E;
> >    use type Ada.Streams.Stream_Element;
> >    First_Character : Natural := 0;
> >    Base : constant  := 16;
> > begin
> >    for K in reverse Result'First .. Result'Length loop
>
> (2) and this should be:
>
>      for K in reverse Result'Range loop
>
> >       Result (K) := X (integer(Working_Copy) mod integer (Base) );
>
> (3) and thanks to (1), this can come back to the simpler:
>
>        Result (K) := X (Working_Copy mod Base);
>
> >       Working_Copy := Working_Copy / Base;
> >       if Working_Copy = 0 then
> >          First_Character := K;
> >          exit;
> >       end if;
> >    end loop;
> >    return Result (First_Character .. Result'Last);
> > end To_Hex;
>
> > It still seems to be dropping a few zeros though and I'm stumped where
> > its going wrong
>
> I tested it with 42 and 0 and correctly got 2A and 0, so I don't know
> what you mean by that.
>
> Maybe the fact that the result has a variable width is a problem?  If
> so, here is a fixed-width variant which is actually a bit simpler:
>
> function To_Hex (E : in Ada.Streams.Stream_Element) return String is
>    X : constant array (Ada.Streams.Stream_Element range 0 .. 15)
>      of Character :=
>      ('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C',
>       'D', 'E', 'F');
>    Result : String
>      (1 .. Ada.Streams.Stream_Element'Size / 4) -- 1 hex digits = 4 bits
>      := (others => '0');
>    Working_Copy : Ada.Streams.Stream_Element := E;
>    use type Ada.Streams.Stream_Element;
>    Base : constant := 16;
> begin
>    for K in reverse Result'Range loop
>       Result (K) := X (Working_Copy mod Base);
>       Working_Copy := Working_Copy / Base;
>    end loop;
>    return Result;
> end To_Hex;
>
> and this yields 2A and 00 for my "test vector".
>
> --
> Ludovic Brent

Its the variable width I think.
From: Peter Hermann on 20 Apr 2010 05:25
tonyg <tonythegair(a)googlemail.com> wrote:
> Its the variable width I think.

http://en.wikipedia.org/wiki/Netiquette
and
http://tools.ietf.org/html/rfc1855
for postings, look for:
But do not include the entire original!

alternative: many CTRL-K
From: Warren on 20 Apr 2010 10:04
Adam Beneschan expounded in news:32ac71bf-cd1e-4068-a0a6-
9491b4750e8d(a)y38g2000prb.googlegroups.com:

...
>> Now if only I could find where the mayonnaise in the
>> fridge is..
>
> It got shoved in the back, behind that leftover chicken casserole
> that's been there way too long and needs to be thrown out.
>
> Hope this helps,
>
> -- Adam

Ew!

I guess it helps not to have preconceptions when looking
for stuff. I looked for a "white" jar of mayonnaise and of
course couldn't find it. This was because my wife bought
mayonnaise in a yellow plastic jar (recently), which I
mistook for mustard. She of course, had no trouble at
all finding it.

Warren
From: J-P. Rosen on 20 Apr 2010 10:46
Warren a �crit :

> I guess it helps not to have preconceptions when looking
> for stuff. I looked for a "white" jar of mayonnaise and of
> course couldn't find it. This was because my wife bought
> mayonnaise in a yellow plastic jar (recently), which I
> mistook for mustard. She of course, had no trouble at
> all finding it.
>
Now, you understand the importance of having unambiguous specifications
that match the implementation (back on topic) ;-)

--
---------------------------------------------------------
J-P. Rosen (rosen(a)adalog.fr)
Visit Adalog's web site at http://www.adalog.fr
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