Unused selects in SHTOLO

[Hendrix, Thomas E]

(Theoretical question only) Why not allow extensions that are unnamed,
that only extend the selected (enumerated) items.


Regards,
Tom

Thomas E. Hendrix
Phone: 206-544-5276
thomas.e.hendrix at boeing.com



-----Original Message-----
From: Ed Barkmeyer [mailto:edbark at nist.gov] 
Sent: Tuesday, October 14, 2003 5:18 AM
To: Rob Bodington
Cc: expressIF at tc184-sc4.org; wg11 at steptools.com
Subject: Re: Unused selects in SHTOLO


Rob is correct that the process of extending EXTENSIBLE SELECT types
produces 
artifact select types that have no use.  This may or may not also apply
to 
EXTENSIBLE ENUMERATION types.

I have no objection to the rule Rob intends, but I think we may want to
be a bit 
careful about the wording:

(1) The rule should include both SELECT types and ENUMERATION types, and
could 
in general apply to any data type that is created by a TYPE declaration
and has 
no "role" (is not the data type of any attribute) in the resulting
schema.  Any 
such data type need not be included in the long form schema, but:

(2) When a SELECT data type plays a role, every (interfaced) data type
in the 
select list of that select type also plays that role.

(3) When a defined data type is included in the long-form schema, its 
underlying-type must be included in the schema, even if it plays no
role.

-Ed

-- 
Edward J. Barkmeyer                       Email: edbark at nist.gov
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Mail Stop 8260          Tel: +1 301-975-3528
Gaithersburg, MD 20899-8260               FAX: +1 301-975-4694

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