SEDS for ISO 10303-11

[Jochen Haenisch]

Daivd,

yes, I do mean that this applies to more than NUMBER! Think of an example
with PERSON and subtypes MAN and WOMAN. That would make more sense.
If I am not mistaken, SDAI offers the required functionality in
is_instance_of/is_kind_of.

Regards, Jochen.

> -----Original Message-----
> From:	David Price [SMTP:david.price at eurostep.com]
> Sent:	29. november 2001 13:57
> To:	Jochen Haenisch
> Cc:	'WG11 exploder'; Hans Karsten Dahl
> Subject:	RE: SEDS for ISO 10303-11
> 
> Hi Jochen,
> 
> My two kroner...
> 
> I do agree NUMBER is a strange datatype but I'm not sure that means the
> relationship between it and a specialiation of it should be treated
> differently OR do you mean for this to apply to more than NUMBER?
> 
> > An implementation will nontheless keep track of the actual type of an
> > object. So, why not give the user the (necessary) possibility to
> > query this?
> 
> I'm not sure it's a good idea to assume this for all implementations.
> Functionally, NUMBER is treated like REAL in many of the 20s series parts
> so
> implementations may lose the distinction. However, I've not implemented
> this
> myself so will leave that issue to others.
> 
> Cheers,
> David
> 
> > -----Original Message-----
> > From: Jochen Haenisch [mailto:Jochen.Haenisch at epmtech.jotne.com]
> > Sent: 2001 November 29 12:24
> > To: 'david.price at eurostep.com'
> > Cc: 'WG11 exploder'; Hans Karsten Dahl
> > Subject: RE: SEDS for ISO 10303-11
> >
> >
> > David,
> >
> > no, the point is not to detect that a BAG is a SET based on the
> > characteristics of its population. This is beyond the limits, but not
> very
> > much. The point is to have a possibility to query which type of value
> has
> > intentionally been assigned to a parameter.
> >
> > Building on the previous example one could imagine the following
> > situation:
> >
> >  LOCAL
> >    x : NUMBER;
> >    y: REAL := 1.0;
> >    z: INTEGER := 2;
> >  END_LOCAL;
> >
> >  IF (...) THEN x:=y;
> >  ELSE x:=z;
> >  END_IF;
> >
> >  IF ('REAL' IN TYPEOF(x)) THEN ...; END_IF;
> >
> > Even though this may not be the most convincing real life example, I
> hope
> > you see the usefulness of TYPEOF returning the type of the value that
> has
> > been assigned to it. How else could one treat x differently based on the
> > type that it is carrying around?
> > An implementation will nontheless keep track of the actual type of an
> > object. So, why not give the user the (necessary) possibility to
> > query this?
> >
> > Best regards, Jochen.
> >
> > > -----Original Message-----
> > > From:	David Price [SMTP:david.price at eurostep.com]
> > > Sent:	29. november 2001 12:13
> > > To:	Jochen Haenisch
> > > Cc:	'WG11 exploder'
> > > Subject:	RE: SEDS for ISO 10303-11
> > >
> > > Jochen,
> > >
> > > I'm not sure I like the idea that the datatype of something
> > depends on its
> > > instantiated value. TYPEOF is a datatype, not data value,
> > function so I'm
> > > a
> > > bit confused. Can you elaborate on why you want this change? Is this
> > > example
> > > any different from x being declared as a BAG that happens to be
> > > instantiated
> > > with non-duplicate members and so you want TYPEOF to return SET?
> > >
> > > Hope my question makes sense. It's basically, how far would you expect
> > > this
> > > proposal to go?
> > >
> > > Cheers,
> > > David
> > >
> > > > -----Original Message-----
> > > > From: owner-wg11 at steptools.com [mailto:owner-wg11 at steptools.com]On
> > > > Behalf Of Jochen Haenisch
> > > > Sent: 2001 November 29 09:02
> > > > To: 'seds at cme.nist.gov'
> > > > Cc: 'WG11 exploder'
> > > > Subject: SEDS for ISO 10303-11
> > > >
> > > >
> > > > Please, consider the SEDS report that is included below.
> > > > Best regards, Jochen Haenisch.
> > > >
> > > >  <<SEDS_Express_20011129.txt>>
> > > >
> > > > ____________________________________________________________
> > > > Jochen Haenisch			E-mail:
> > > > Jochen.Haenisch at epmtech.jotne.com
> > > > EPM Technology AS		Home of the EXPRESS Data Manager
> > > > P.O Box 6629 Etterstad		Tel: Int + 47 23 17 17 26
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> > > >
> > > >