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Date: 3 Jun 93 14:44:34 GMT
From: jeffe@midway.uchicago.edu  (Jeff Etrick)
Subject: Representation clauses
Message-ID: <257@sphinx.CSS.GOV>
List-Id: <comp.lang.ada>

Dear Netters,

  I have inherited a program that has been around for a while and the
users have a fair number of files generated from it. With the recent
upgrade of my compiler the binary output files are no longer compatible. In
looking over the code I have noticed the former programmers did not use
any representation clauses for their output records. I have since been
working on adding these to the current system. My problem is I have a
variant record I see no way of putting a representation clause on.

  subtype Small_Natural is NATURAL range 0..300;

  type String_Record (Max_Length : Small_Natural := Small_Natural'Last)
  is record
    Length : Small_Natural := 0;
    Name   : String(1..Max_Length) := (others => ' ');
  end record;
  
  type Catalog
  is record
    File_Name : String_Record;
    File_Description : String_Record;
  end record;

  Since I have been going in and changing things anyway my question is what
is the  best way to change the above so I am not bit again due to version
or a compiler change?

  One idea I was thinking about was writing an Integer(the length) followed
by a fixed length string, Internally the code would still use the variant
records with only the reading and writing of file routines changing.


Thanks for any advice,

Jeff
jeffe@osiris.css.gov