Re: Ada Compiler Complaint ?

["David C. Hoos" <david.c.hoos.sr@ada95.com>]

First let me apologize for misunderstanding your original post
and providing an erroneous response.

I was thinking you were writing binary data, when in fact you're
writing text.

At any rate, the following code compiles and links without error
or warning on Linux with gnat 3.12p, and produces the following
output:

10000010010000101100001000100010101000100110001011100010

So... from the incomplete code you supplied, and the lack of information
about the compiler and the platform being used, I am unable to intuit
what the problem might be.

with Ada.Text_IO;
with System;
package X is
   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 (Buffer  : System.Address;
                Size    : Integer;
                Outfile : Ada.Text_IO.File_Type);
end X;

with Ada.Unchecked_Conversion;
package body X is
   function To_Bit_Array is new
     Ada.Unchecked_Conversion (System.Address,Bit_Array_Ptr);
   procedure Y (Buffer  : System.Address;
                Size    : Integer;
                Outfile : Ada.Text_IO.File_Type) is
      A_Bit_Array : Bit_Array_Ptr;
   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;
end X;

with Ada.Text_IO;
with System;
with X;
procedure Test_X is
   File : Ada.Text_IO.File_Type;
   Data : String := "ABCDEFG";
   Buffer : System.Address := Data'Address;
begin
   Ada.Text_IO.Create (File, Ada.Text_IO.Out_File, "x.dat");
   X.Y (Buffer, Data'Length, File);
end Test_X;

----- Original Message -----
From: "Dale Pennington" <dalepenn@hiwaay.net>
Newsgroups: comp.lang.ada
To: <comp.lang.ada@ada.eu.org>
Sent: Tuesday, August 28, 2001 7:10 AM
Subject: Re: Ada Compiler Complaint ?


> 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
> > >
> >
>
>
>
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