Issue 4700: Multiplicity be optional for non-navigable association ends. (mof-rtf) Source: International Business Machines (Dr. Stephen Brodsky, Ph.D, sbrodsky(at)us.ibm.com) Nature: Uncategorized Issue Severity: Summary: If an association end is not navigable, specification of its Multiplicity should not be required. There is no practical use for this information and it does not make sense to require information that is not used. Proposed Resolution: Make Multiplicity optional in the MOF model. Resolution: Revised Text: Actions taken: November 12, 2001: received issue Discussion: End of Annotations:===== Importance: Normal Subject: [mof-rtf] Multiplicity should be optional for non-navigable association ends To: mof-rtf@omg.org, issues@omg.org X-Mailer: Lotus Notes Release 5.0.4a July 24, 2000 Message-ID: From: "Stephen Brodsky" Date: Mon, 12 Nov 2001 08:11:39 -0800 X-MIMETrack: Serialize by Router on D03NM039/03/M/IBM(Release 5.0.8 |June 18, 2001) at 11/12/2001 09:09:29 AM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-UIDL: ?):e9"bod9k]dd96>Je9 Dear MOF RTF, Issue: Multiplicity be optional for non-navigable association ends. Summary: If an association end is not navigable, specification of its Multiplicity should not be required. There is no practical use for this information and it does not make sense to require information that is not used. Proposed Resolution: Make Multiplicity optional in the MOF model. Thanks, -Steve Stephen A. Brodsky, Ph.D. Software Architect, STSM Notes Address: Stephen Brodsky/Santa Teresa/IBM@IBMUS Internet Address: sbrodsky@us.ibm.com Phone: 408.463.5659 From: "Martin Matula" To: , , "Stephen Brodsky" References: Subject: Re: [mof-rtf] Multiplicity should be optional for non-navigable association ends Date: Mon, 12 Nov 2001 19:12:09 +0100 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Content-Type: text/plain; charset="iso-8859-1" X-UIDL: ZEB!!6[cd9~DDe9W%+!! Hi Steve, I think that the multiplicity on both association is useful even if one of the association ends is not navigable. Multiplicity of non-navigable end expresses, from how many objects you can navigate to the same object (how many objects can point to the same object). E.g. if you have association Extends (like in Java), where supertype is navigable and subtype is not navigable (so you can get only from subtype to its supertype and not vice versa), the multiplicity of subtype still counts (e.g. if you would set it to 1..1, you would not be able to set the same supertype for any two classes - that would mean that each class would need to have a different supertype, however having multiplicity 1..n means, that any number of classes can point to the same class as their superclass). Martin ----- Original Message ----- From: "Stephen Brodsky" To: ; Sent: Monday, November 12, 2001 5:11 PM Subject: [mof-rtf] Multiplicity should be optional for non-navigable association ends > Dear MOF RTF, > > Issue: Multiplicity be optional for non-navigable association >ends. > > Summary: If an association end is not navigable, specification of >its > Multiplicity should not be required. There is no practical use for >this > information and it does not make sense to require information that >is not > used. > > Proposed Resolution: Make Multiplicity optional in the MOF model. > > Thanks, > > -Steve > > Stephen A. Brodsky, Ph.D. > Software Architect, STSM > Notes Address: Stephen Brodsky/Santa Teresa/IBM@IBMUS > Internet Address: sbrodsky@us.ibm.com > Phone: 408.463.5659 > X-Mailer: exmh version 2.2 06/23/2000 with nmh-1.0.4 To: "Stephen Brodsky" cc: mof-rtf@omg.org, crawley@dstc.edu.au Subject: Re: [mof-rtf] Multiplicity should be optional for non-navigable association ends In-Reply-To: Message from "Stephen Brodsky" of "Mon, 12 Nov 2001 08:11:39 PST." Mime-Version: 1.0 Date: Tue, 13 Nov 2001 09:49:24 +1000 From: Stephen Crawley X-Scanned-By: MIMEDefang 1.0 (http://www.roaringpenguin.com/mimedefang/) Content-Type: text/plain; charset=us-ascii X-UIDL: >!n!!,~;e9>C4!!AH_d9 Steve, The multiplicity on an AssociationEnd constrains the number of objects that may linked to an object matching this end. This applies whether the AssociationEnd is navigable or not, and whether or not there are any References. Refer to Section 4.9.2.1 for a precise specification of what the multiplicities on AssociationEnds mean. In particular, look at item 6. which defines a "well-formed state" for an Association instance. >>MY<< proposed resolution: close with no change to the specification. -- Steve Importance: Normal X-Mailer: Lotus Notes Release 5.0.4a July 24, 2000 MIME-Version: 1.0 Subject: Re: [mof-rtf] Multiplicity should be optional for non-navigable association ends To: Message-ID: From: "Stephen Brodsky" Date: Tue, 13 Nov 2001 15:24:44 -0800 X-MIMETrack: Serialize by Router on D03NM039/03/M/IBM(Release 5.0.8 |June 18, 2001) at 11/13/2001 04:34:22 PM Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by emerald.omg.org id fADNRWK09052 Content-Type: text/plain; charset=iso-8859-1 X-UIDL: p$1!!@,9e9g3`!!)VX!! Martin, In the cases where there is something interesting, it is fine to set the multiplicity as before. I think these cases will be rare and so it should not be required for the common cases where the model does not contain information. A multiplicity for the Multiplicity of 0..1 handles both situations. Thanks, -Steve Stephen A. Brodsky, Ph.D. Software Architect, STSM Notes Address: Stephen Brodsky/Santa Teresa/IBM@IBMUS Internet Address: sbrodsky@us.ibm.com Phone: 408.463.5659 To: , , Stephen Brodsky/Santa Teresa/IBM@IBMUS cc: Subject: Re: [mof-rtf] Multiplicity should be optional for non-navigable association ends Hi Steve, I think that the multiplicity on both association is useful even if one of the association ends is not navigable. Multiplicity of non-navigable end expresses, from how many objects you can navigate to the same object (how many objects can point to the same object). E.g. if you have association Extends (like in Java), where supertype is navigable and subtype is not navigable (so you can get only from subtype to its supertype and not vice versa), the multiplicity of subtype still counts (e.g. if you would set it to 1..1, you would not be able to set the same supertype for any two classes - that would mean that each class would need to have a different supertype, however having multiplicity 1..n means, that any number of classes can point to the same class as their superclass). Martin ----- Original Message ----- From: "Stephen Brodsky" To: ; Sent: Monday, November 12, 2001 5:11 PM Subject: [mof-rtf] Multiplicity should be optional for non-navigable association ends > Dear MOF RTF, > > Issue: Multiplicity be optional for non-navigable association >ends. > > Summary: If an association end is not navigable, specification of >its > Multiplicity should not be required. There is no practical use for >this > information and it does not make sense to require information that >is not > used. > > Proposed Resolution: Make Multiplicity optional in the MOF model. > > Thanks, > > -Steve > > Stephen A. Brodsky, Ph.D. > Software Architect, STSM > Notes Address: Stephen Brodsky/Santa Teresa/IBM@IBMUS > Internet Address: sbrodsky@us.ibm.com > Phone: 408.463.5659 >