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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: maintenance of overriding subprograms
Date: 1997/09/07
Message-ID: <dewar.873631018@merv>#1/1
X-Deja-AN: 270502358
References: <340C2EA5.B9F@gsfc.nasa.gov> <340DCE1D.6C5F@bix.com>
Organization: New York University
Newsgroups: comp.lang.ada
Date: 1997-09-07T00:00:00+00:00
List-Id: <comp.lang.ada>


<<Clearly this error mode can occur without OO programming, but it's
likely to become substantially more common with heavy use of derived
types.>>

What would be more interesting is to hear from people who have actually
found this to be a problem ... often language experts sit around imagining
things that do not really happen, so the most useful input on errors is
input from people who actually run into them.

Certainly in the case of GNAT, both the compile time and runtime error handling
and in particular the choice of warnings that are needed are very much
conditioned by user experience in running into problems.

All the problems Tom Moran mentions can probably be significantly
ameliorated by some additional warning messages, but I would hesitate
to implement such warnings unless I heard from at least one user who
said they had run into trouble. So far, among the thousands of GNAT
users over several years of use, many of whom are not shy about making
suggestions for new messages and warnings :-) no one has commented that
this was a trouble spot.