How does one use Ada.Streams.Stream_IO?

How does one use Ada.Streams.Stream_IO?

[Matthew Kennedy]

Hello all,

OK, the solution to my multiple-record-types-from-the-one-file problem
is Ada.Streams.Stream_IO. However, I don't know how to instantiate(?) it
properly.

Does anyone have a simple example of how to do this?

Sources of examples I've already tried:

  * examples the come with GNAT for DOS
  * cs1code
  * cs2code
  * lovelace tutorial
  * ada tutor

  * books

But these have no mention of stream operations.

Thanks,
Matt

-- 
Matthew Kennedy
Student of Electronics Engineering
University of Southern Queensland, Australia
  "When will you realise your already there?" 
      - Marilyn Manson

Re: How does one use Ada.Streams.Stream_IO?

[Jon S Anthony]

In article <33DF3D90.155D@mail.connect.usq.edu.au> Matthew Kennedy <q9522772@mail.connect.usq.edu.au> writes:

> OK, the solution to my multiple-record-types-from-the-one-file problem
> is Ada.Streams.Stream_IO. However, I don't know how to instantiate(?) it
> properly.
> 
> Does anyone have a simple example of how to do this?
> 
> Sources of examples I've already tried:
> 
<...>
> 
> But these have no mention of stream operations.

Well, Barnes covers this in reasonable detail in 20.6 of _Programming
in Ada95"_.  Cohen covers this too - somewhere toward the end of the
book (I have Barnes handy, but not Cohen...)

/Jon
-- 
Jon Anthony
OMI, Belmont, MA 02178
617.484.3383
"Nightmares - Ha!  The way my life's been going lately,
 Who'd notice?"  -- Londo Mollari

Re: How does one use Ada.Streams.Stream_IO?

[Robert Dewar]

Matt asks

<<OK, the solution to my multiple-record-types-from-the-one-file problem
is Ada.Streams.Stream_IO. However, I don't know how to instantiate(?) it
properly.
>>


Well you won't get very far trying to instantiate Stream_IO, since it is
not a generic package! Just with it, and then use the subprograms much
as you would in the case of Text_IO, except that the actual stream
operations are typically done using the standard stream attributes,
e.g. x'Output (stream, item) to write and X'Input (Stream) to read.

Re: How does one use Ada.Streams.Stream_IO?

[Pascal Obry]

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Here is a small example :

with Ada.Streams.Stream_IO;

procedure Streams is

   use Ada;

   Max_Datas : constant := 100_000;
   type Datas is array (1 .. Max_Datas) of Integer;

   D : Datas := (1 | 2 | 4 | 6 | 8 => 50, others => 1);

   procedure Write_Stream is
      package Data_IO renames Ada.Streams.Stream_IO;
      F : Data_IO.File_Type;
   begin
      Data_IO.Create (F, Name => "tmp_s.data", Mode => Data_IO.Out_File);
      for I in D'Range loop
         Integer'Write (Data_IO.Stream (F), D(I));
      end loop;
      Data_IO.Close (F);
   end Write_Stream;

   procedure Write_Array_Stream is
      package Data_IO renames Ada.Streams.Stream_IO;
      F : Data_IO.File_Type;
   begin
      Data_IO.Create (F, Name => "tmp_a.data", Mode => Data_IO.Out_File);
      Datas'Write (Data_IO.Stream (F), D);
      Data_IO.Close (F);
   end Write_Array_Stream;

begin
    null;
end Streams;


Hope this helps,
Pascal.
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