Re: Streams Quandry in Ada95 (SOLVED)

["Warren W. Gay VE3WWG" <ve3wwg@home.com>]

"Warren W. Gay VE3WWG" wrote:

> I just got an email from  Sergey Koshcheyev <serko84@hotmail.com> who I think
> has solved this riddle (to be confirmed tonight).  He says: "it looks that the problem
> is you're using Audio_Stream as both the package name and the type name, so the
> compiler is getting confused..."  I think he may be right.

He was right. When I renamed the package to Audio_Streams (plural), this removed
the confusion with the type:

type Audio_Stream is access all Audio_Stream_Type'Class;

With the original name conflict in place, the things I thought were legal to do, were not.
Being relatively new to Ada, I assumed that I was doing something that I shouldn't
be able to do. Once I renamed the package, as per Sergey's advice, I was then able
to do the things I thought you could do.  I defined :

    procedure Pump(In_Str, Out_Str: Audio_Stream)

as required.  To access derived primitives on Au_Stream, all I now need
to do is:

    Chans := Channels(In_Str.All);  -- Determine the # of input audio channels

To set the # of channels on the Out_Str, (for DSP_Stream) then:

    Set_Channels(Out_Str.All,Chans);  -- Configure DSP to use n channel output

The Read/Write on the stream now works as expected:

    Audio_I32'Read(In_Str,I);    -- Read 32 bit int

Life is good!  Thanks everybody.  Sergey wins the prize ;-)

This is the 2nd time I was burnt by the package name.  This time, I'll remember
the lesson.

--
Warren W. Gay VE3WWG
http://members.home.net/ve3wwg