From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,740e91341085efe3
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news3.google.com!news.glorb.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.comcast.com!news.comcast.com.POSTED!not-for-mail
NNTP-Posting-Date: Thu, 07 Apr 2005 23:43:33 -0500
From: tmoran@acm.org
Newsgroups: comp.lang.ada
Subject: Re: Some help for a C++ guy
References: <1112912062.146885.324110@o13g2000cwo.googlegroups.com>
X-Newsreader: Tom's custom newsreader
Message-ID: <dYidnVI1vrZrlsvfRVn-1w@comcast.com>
Date: Thu, 07 Apr 2005 23:43:34 -0500
NNTP-Posting-Host: 67.161.24.234
X-Trace: 
 sv3-wQchm3yJ8oEYYUw/APvSms+MtxK3Yq9Ojm4VHqlXdQFoliVBGoT30Q52d6FT8yF+r274xPUDE/QECgh!clHwL+BNNMs6NiznydHPEkKS32mwKWKFW1Vd+Tda4OtUU3Q5UDi8PQu7ppAiAA==
X-Complaints-To: abuse@comcast.net
X-DMCA-Complaints-To: dmca@comcast.net
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint
 properly
X-Postfilter: 1.3.31
Xref: g2news1.google.com comp.lang.ada:10328
Date: 2005-04-07T23:43:34-05:00
List-Id: <comp.lang.ada>

>generic
>package Message_Handler is
>   procedure Message_Callback (Status : in M1553.IO_Status_T);
>...
>   function Num_Message_Callbacks return OS_Types.Unsigned_Word;
>...
>  Data_Buf_Ptr : constant M1553.Data_Buf_VPtr_T := new M1553.Data_Buf;
>  Stat_Buf_Ptr : constant M1553.Status_Buf_VPtr_T := new M1553.Status_Buf_T;
>...
>Then in the implementation code, there's stuff like:
>
>   package Message_0_Handler is new Message_Handler;
>   package Message_5_Handler is new Message_Handler;
>...
>I don't much like this. It's cumbersome even for a couple of messages,
>let alone when we grow to 20 or more, because we have duplicated code
>for each registration.
>
>What I'd like is to have some sort of array of the messages. That way
>for errors. I guess I'm thinking an OO approach, as long as the various
>members could be passed as arguments to the registration routines.
  Since the generic has no parameters, what you're getting is in effect
a single body of code, with separate data for each instantiation, and
you call
  Message_0_Handler.Message_Callbacks (Status);
instead of
  Message_Handler.Message_Callbacks (Message_0, Status);

So you could just drop the "generic" and put the package's local data
into a record:

 package Message_Handler is

    type Message_State_Type is private;

    procedure Message_Callback (State  : in Message_State_Type;
                                Status : in M1553.IO_Status_T);
 ...
    function Num_Message_Callbacks (State  : in Message_State_Type)
    return OS_Types.Unsigned_Word;
 ...
    -- make Data_Buf_Ptr readable, but not writeable
    function Data_Buf_Ptr (State  : in Message_State_Type)
    return M1553.Data_Buf_VPtr_T;

    function Stat_Buf_Ptr (State  : in Message_State_Type)
    return M1553.Status_Buf_VPtr_T;
 ...

Then you could have
    Message_List : array(0 .. 5) of Message_State_Type;
and call
    Message_Handler.Message_Callback (Message_List(0), Status);
    etc
That seems the most vanilla change, and you can probably change all
your source code by a simple macro in your editor.
Or am I missing something?