Re: Ada Streams usage (was Escape Sequences in Strings)

[Brian Orpin <abuse@borpin.co.uk>]

On Sun, 19 Nov 2000 13:33:51 -0500, Marin David Condic
<mcondic.nospam@acm.org> wrote:

>Marin David Condic wrote:
>
>> I'll see what I can do to trim down a small example and post it here.

<snip>
>    type My_Stream_Type is new Ada.Streams.Root_Stream_Type with record
>        --
>        --  This is where you would retain information about I/O buffers,
>        --  I/O ports, etc. so that Read and Write can know where to
>        --  retreive or send their data. A simple case might be a big ring
>        --  buffer with Write attaching to the end and Read pulling stuff
>        --  off from the beginning. Not really useful, but it makes the
>        --  point.
>        --
>        null ;
>    end record ;

Can't see how information on the IO buffers goes in here.

>    procedure Read (
>        Stream  : in out My_Stream_Type ;
>        Item    :    out Ada.Streams.Stream_Element_Array ;
>        Last    :    out Ada.Streams.Stream_Element_Offset) is
>        --
>        --  This is called automagically from the background as things
>        --  are being converted by Something'Read.
>        --
>    begin
>        --
>        --  Normally, you'd do something to access a low-level I/O
>        --  device or use some other means to get hold of raw bytes
>        --  from some source at this point in the code. Here we
>        --  just fill it with zeros as a not too useful example.
>        --
>        for X in Item'Range loop
>            Item (X) := 0 ;
>        end loop ;
>        Last    := Item'Last ;
>    end Read ;

It is the bit about getting the raw bytes that interested me.  I was
hoping that Streams did a bit more but obviously not.

I just can't believe that someone hasn't done this and made it available.
It is such a common problem.  Ho Hum I suppose I will need to find the
time to do it.

-- 
Brian Orpin    BAE SYSTEMS, Edinburgh
"If you really know C++, there isn't much you can't do with it, though it may 
not always be what you intended!"  Tucker Taft 1998