Issue 1492:  Alignment with UML Constraints (boca-rtf)
Source:  (, )
Nature:  Revision
Severity: 
Summary: Summary: Aligment with UML—Constraints
 
 Stated as only a general issue at this point:  The model for expressions and constraints could probably be 
 better aligned with UML, understanding, however, that UML does not rigorously model expressions the way 
 BOCA does.  Nevertheless, UML has a Constraint meta-type with very clear associations with other meta-
 type elements.  BOCA could probably come very, very close to that, while preserving its expression meta-
 model.
 
 However, the BOCA expression language may not be powerful enough to state the kinds of constraints 
 required by a precise contract for a type.  For example, see issues 18, 25, and 48 for cases where the 
 expression language may not support  the expression of certain required constraints. 
 
 Therefore, it may be wise to allow OCL expressions as an optional expression form.and to provide a meta-
 model for it.  The BOCA submitters have already done quite a bit of work in this area and OCL was in and 
 out of various versions of BOCA.  Proper alignment with UML would require subtyping UML to provide a 
 rigorous meta-model for OCL, so that OCL constraints can appear in tractable form in UML metadata.  The 
 BOCA OCL meta-model would be as isomorphic as possible with the UML OCL meta-model, while 
 incorporating the CORBA data types.
 
 Recommendation: Close study of this issue, with input from OADTF and BOCA RTF.
 

Resolution: 
Revised Text:   The model for expressions and constraints could probably be 
Actions taken:
June 3, 1998: received issue
Discussion: 

End of Annotations:=====
*ISSUE 63*

Aligment with UML-Constraints

Stated as only a general issue at this point:  The model for
expressions and constraints could probably be better aligned with UML,
understanding, however, that UML does not rigorously model expressions
the way BOCA does.  Nevertheless, UML has a Constraint meta-type with
very clear associations with other meta-type elements.  BOCA could
probably come very, very close to that, while preserving its
expression meta-model.

However, the BOCA expression language may not be powerful enough to
state the kinds of constraints required by a precise contract for a
type.  For example, see issues 18, 25, and 48 for cases where the
expression language may not support  the expression of certain
required constraints. 

Therefore, it may be wise to allow OCL expressions as an optional
expression form.and to provide a meta-model for it.  The BOCA
submitters have already done quite a bit of work in this area and OCL
was in and out of various versions of BOCA.  Proper alignment with UML
would require subtyping UML to provide a rigorous meta-model for OCL,
so that OCL constraints can appear in tractable form in UML metadata.
The BOCA OCL meta-model would be as isomorphic as possible with the
UML OCL meta-model, while incorporating the CORBA data types.

Recommendation: Close study of this issue, with input from OADTF and
BOCA RTF.