E2 to E1 SHTOLO test files

Jochen Haenisch Jochen.Haenisch at epmtech.jotne.com
Wed May 8 04:02:29 EDT 2002 

Hi guys,

we do not have a problem with one language identifier per schema. If we
agree on this, may we suggest to have this identifier between SCHEMA and
END_SCHEMA, probably as one of the first statements - not outside, as
currently proposed?!

Best regards, Jochen.
____________________________________________________________
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; mobile: Int + 47
922 60 274
N-0607 Oslo				Fax: Int + 47 23 17 17 01  
Norway					Web:  http://www.epmtech.jotne.com

> -----Original Message-----
> From:	Wilson, Peter R [SMTP:peter.r.wilson at boeing.com]
> Sent:	8. mai 2002 00:39
> To:	'Phil.Spiby at eurostep.com'; Jochen Haenisch; Wilson, Peter R
> Cc:	Hans Karsten Dahl; wg11 at steptools.com; Hendrix, Thomas E; Arne Tøn
> Subject:	RE: E2 to E1 SHTOLO test files
> 
> All,
> 
>     Just to jump in again, I think the situation we have is a bit more
> complex than Phil likes to think of it.
> 
>     I know that I originally mentioned files, but that is not the basic
> point. We have to deal with a collection of schemas, whether they are in
> one
> file or multiple files.
> 
>     STEP has a collection of schemas, most (all?) of which are Ed1.
> Modules
> are planning on using Ed2, and I am also producing Ed1 IRs
> leading to an Ed2 AP (hopefully using modules).
> 
>     We can parse each schema seperately, but unless the schema is
> completely
> self-contained there will be unidentified references. Generally speaking,
> it
> will be necessary at some point to handle multiple schemas with no
> guarantee
> that they will all be Ed1 or all Ed2; more likely in future the guarantee
> is
> that they will be mix of Ed1 and Ed2.
> 
>     We do have to check that a schema corresponds to Ed1 or Ed2 as
> appropriate, and that a mix of Ed1 and Ed2 schemas do form a complete
> model.
> We either have to parse and `link' and link a collection
> of Ed1 and Ed2 schemas, or we have to seperately parse a collection of Ed1
> schemas and a collection of Ed2 schemas and then link the two collections.
> 
>     Any future Shtolo process will have to handle Ed1 and Ed2
> simultaneously. 
> 
>     We must not force parser vendors into a parse and then link process,
> the
> LRM must let them be free to decide how they can best deal with an Ed1/Ed2
> collection.
> 
>     Granted Ed1 schemas can be parsed by an Ed2 parser, but the reverse is
> not true. A parser must know what it is expected to parse. If Ed3 does
> miraculously appear then the situation will be worse than it is now, as
> since it plans on getting rid of SET it means that an Ed3 parser will not
> be
> able to parse Ed1 or Ed2.
> 
>     Better fix the problem now. The EXPRESS Committee has had enough
> bitter
> experiences in not fixing something that was bad.
> 
>     Ed suggested that either the language_version_id goes with "all the
> schemas you need" or "each schema seperately". My answer is that it has to
> be "each schema seperately".
> 
> Peter W.
> 
> Dr Peter R. Wilson
> Boeing Commercial Airplanes
> PO Box 3707, MS 6H-AF, Seattle, WA 98124-2207
> (Package Delivery: MS 6H-AF, 1601 E. Valley Frontage Road, Renton, WA
> 98055)
> Tel: (425) 237-3506, Fax: (425) 237-3428
> Email: peter.r.wilson at boeing.com
> --------------------------------
> Any opinions expressed above are personal;
> they shall not be construed as representative of any organisation.
> --------------------------------
>  
> 
> > -----Original Message-----
> > From: Phil Spiby [mailto:Phil.Spiby at eurostep.com]
> > Sent: Tuesday, May 07, 2002 2:17 PM
> > To: Jochen Haenisch; 'Wilson, Peter R'
> > Cc: Hans Karsten Dahl; wg11 at steptools.com; Hendrix, Thomas E; Arne Tøn
> > Subject: RE: E2 to E1 SHTOLO test files
> > 
> > 
> > Folks,
> > 
> > I remember the discussion with Peter etc. but my 
> > understanding was that
> > there was no change agreed to the DAM.
> > 
> > My personal understanding of this situation, which is open to 
> > dispute, is
> > the following:
> > EXPRESS has deliberately avoided the use of the term file, since to
> > acknowledge files, we then need a means of defining 
> > relationships between
> > files, like #include etc.
> > The concept of file is probably wrong if you are considering 
> > an interactive
> > development environment (this was an aims of some of the 
> > original EXPRESS
> > committee).
> > The way we tried to get around this was to introduce the idea 
> > that some
> > mechanism would enable either an environment or a collection 
> > of files to be
> > dealt with as a complete unit, and that this complete unit 
> > would obey the
> > rules of the Syntax and allow a scope for schema names to 
> > exist within.
> > Although much of these concepts were removed in the run-up to
> > standardisation in 1994 we still have some legacies in the 
> > standard with
> > keywords such as MODEL and END_MODEL, and the Note under 10.3.13.
> > 
> > It is my belief that this schema aggregation should all obey the same
> > language syntax, and this is why I think the syntax conforms 
> > to a single
> > language version. If we consider the now almost dead Edition3 
> > then Peter's
> > proposal would allow some schemas to correspond to Edition 1, some to
> > edition2 and perhaps some to edition3, i.e. different schemas 
> > would have to
> > be conformance checked against different standards ISO 
> > 10303-11 for editions
> > 1 and 2 and ISO 20303 for edition 3!.
> > 
> > I understand that Peter wants this so that he can easily concatenate a
> > number of files together then parse the result, and I have 
> > some sympathy for
> > this approach. But I feel that if any one schema is to be 
> > parsed against
> > edition two then the whole collection should be parsed at that level.
> > Edition two is, by design and SC4 ruling, upwardly compatible 
> > with edition
> > one!
> > 
> > Phil
> > 
> > > -----Original Message-----
> > > From: owner-wg11 at steptools.com [mailto:owner-wg11 at steptools.com]On
> > > Behalf Of Jochen Haenisch
> > > Sent: Tuesday, May 07, 2002 5:24 PM
> > > To: 'Wilson, Peter R'
> > > Cc: Hans Karsten Dahl; 'wg11 at steptools.com'; Hendrix, 
> > Thomas E; Arne Tøn
> > > Subject: RE: E2 to E1 SHTOLO test files
> > >
> > >
> > > Peter,
> > >
> > > your proposal may well make sense! I just referred to what 
> > I think is
> > > specified in the DAM so far. It will probably be quite 
> > common to generate
> > > longforms out of mixes of e1 and e2 shortforms.
> > >
> > > However, do you think that it is necessary to include 
> > schemas according to
> > > different Express versions in the same file? Should it not 
> > be enough to
> > > specify the language identifier once only in the top of a file?
> > >
> > > Agreed, the LRM does not relate the production term 
> > "syntax" to files. We
> > > should probably be more explicit in e2?!? There seems to be 
> > a source for
> > > misunderstandings.
> > >
> > > I do not think that there is anything related in the issues 
> > resolutions.
> > >
> > > Best regards, Jochen.
> > > ____________________________________________________________
> > > 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;
> > > mobile: Int + 47
> > > 922 60 274
> > > N-0607 Oslo				Fax: Int + 47 23 17 17 01
> > > Norway					Web:
> > > http://www.epmtech.jotne.com
> > >
> > > > -----Original Message-----
> > > > From:	Wilson, Peter R [SMTP:peter.r.wilson at boeing.com]
> > > > Sent:	7. mai 2002 17:55
> > > > To:	'Jochen Haenisch'
> > > > Cc:	'wg11 at steptools.com'; Hendrix, Thomas E; Wilson, Peter R
> > > > Subject:	RE: E2 to E1 SHTOLO test files
> > > >
> > > > Jochen,
> > > >
> > > >     I had a discussion at Myrtle Beach with Phil Spiby on the
> > > question of
> > > > putting the language_version_id before each schema. As far as I
> > > remember,
> > > > Phil said that the assumption was that the entire EXPRESS 
> > model would be
> > > > in
> > > > a single file and that the language_version_id applied to 
> > the file. In
> > > > other
> > > > words, the syntax production applies to a file. The IR53 
> > model is in
> > > > several
> > > > files, and hence the multiple occurrences of the
> > > language_version_id. The
> > > > LRM makes no mention of file(s) containing EXPRESS code.
> > > >
> > > >     What happens if a model is partly Edition 1 (e.g., 
> > the traditional
> > > > IRs)
> > > > and partly Edition 2 (e.g., new IRs like 52 and 53)?
> > > >
> > > >     I think that a language_version_id should be 
> > associable with an
> > > > individual schema, not just with this unexplained concept 
> > of a file. If
> > > > you
> > > > like, change the syntax production to read:
> > > > syntax = [ language_version_id ] schema_decl { 
> > [language_version_id ]
> > > > schema_decl } .
> > > >
> > > > Regards
> > > > Peter W.
> > > >
> > > > PS. I have not yet had a chance to look at Phil's latest list
> > > of issues to
> > > > see if this is in there or not.
> > > >
> >

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