Re: Ada Compiler Complaint ?

["Dale Pennington" <dalepenn@hiwaay.net>]

First, this is code that we are being given by a third party as a library.
Looking at the code segement it is being to used to dump a bit packed buffer
area. The procedure Y kinda looks like this (PS do not hit me on small
syntax errors, this is off the top of my head).

function To_Bit_Array is new
Unchecked_Conversion(System.Address,Bit_Array_Ptr);

procedure Y( buffer : System.Address ;
                       size : integer;
                       Outfile : <filetype, forgot name)
    A_Bit_Array : Bit_Array_Ptr;
    I : integer;
begin
    A_Bit_Array := To_Bit_Array(buffer);

    for I in 1..size*8 loop
       Bit_Io.Put(Outfile,A_Bit_Array(I),1);
    end loop

    ...
end Y;

Suitability aside, I really want to know why the compiler rejects the code.

Thanks
Dale Pennington

David C. Hoos, Sr. <david.c.hoos.sr@ada95.com> wrote in message
news:mailman.998993202.10206.comp.lang.ada@ada.eu.org...
> Since file IO can only be done in whole bytes, what
> was your intention in instantiating Integer_IO for
> your Bit type?  E.g., ion which bit of each byte would
> the data bit reside?
>
> Incidentally, the type bit would probably be better defined
> as mod 2 instead of range 0 .. 1.
>
> ----- Original Message -----
> From: "Dale Pennington" <dalepenn@hiwaay.net>
> Newsgroups: comp.lang.ada
> To: <comp.lang.ada@ada.eu.org>
> Sent: August 27, 2001 10:02 PM
> Subject: Ada Compiler Complaint ?
>
>
> > Folks, looks like my company news server is acting wierd, so I am also
> > posting from a home account. If this shows up twice, just ignore the
second
> > one.
> >
> > I have a chunk of code giving me an error I do not understand. The code
is :
> >
> > package X
> > ...
> > type Bit is range (0..1);
> > for Bit'Size use 1;
> >
> > type Bit_Array is array(1..20000) of Bit;
> > pragma Pack(Bit_Array);
> >
> > type Bit_Array_Ptr is access Bit_Array;
> >
> > package Bit_Io is new Ada.Text_Io.Integer_Io(Bit);
> >
> > ...
> >
> > procedure Y
> > ...
> > A_Bit_Array : Bit_Array_Ptr;
> > begin
> > ...
> > Bit_Io.Put(Outfile,A_Bit_Array(I),1);
> > ...
> > end Y;
> > ...
> > end package X;
> >
> > The compiler complains for the Bit_Io.Put instruction on the column
> > A_Bit_Array starts :
> > expected type "System.Unsigned_Types.Packed_Byte"
> > found type "Bit" defined at xxx.
> >
> > Where xxx is the line the type Bit is at.
> >
> > Anyone know why the compiler is complaining, and what I can do about it
?
> >
> > Thanks
> >
> > Dale Pennington
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > comp.lang.ada mailing list
> > comp.lang.ada@ada.eu.org
> > http://ada.eu.org/mailman/listinfo/comp.lang.ada
> >
>