Re: Record comparison special case

[keniwasa@my-deja.com]

In article <384a1027_2@news1.prserv.net>,
  "Matthew Heaney" <matthew_heaney@acm.org> wrote:
> In article <829bp3$oba$1@nnrp1.deja.com> , keniwasa@my-deja.com
wrote:
>
> > I have a record made up of records in which only small parts (a few
> > fields) are usually significant.
> >
> > The point is that I would like to compare two such records and
determine
> > whether the parts that both records consider to be significant are
the
> > same.  The easiest way I could see to handle this is to have an
> > "insignificant" value in every enumeration and have some
"insignificant"
> > coding for real values, but that's not an option since the types
cannot
> > be modified.
>
> What's wrong with simply redefining the equality operation of the
record
> type?
>
>   type RT is tagged record ... end record;
>
>   function "=" (L, R : RT) return Boolean;
>
> Now you can implement "=" so that just the "small parts" of the L and
R
> records are compared.

Is tagged part of Ada95?  I'm using Ada83.

The problem I had was that the "small parts" are not necessarily the
same for all records.  I also wanted to be able to merge records whose
"small parts" did not conflict and identify records whose "small
parts" did conflict.

>
> --
> Time and again the nation's courts have ruled that creationism, as a
> religious dogma, cannot be taught in science classes. Now,
creationists
> are advancing a new tactic: eliminating the teaching of evolution and
> other sciences that complement evolution, such as geology,
paleontology,
> and biological anthropology. By doing so, they are not only
endangering
> church-state separation but also seriously jeopardizing the science
> education of future generations.
>
> http://www.campusfreethought.org/sos/
>

Ken


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