Issue 10439: Recommendations re ptc/2005-06-06                                                                                                                                                                       (ocl2-rtf)
Source: NIST (Mr. Peter Denno, peter.denno@nist.gov)
Nature: Uncategorized Issue
Severity: 
Summary: Recommendation: The specification would be better were it to additionally 
describe a practical grammar useful to tool implementors and persons trying 
to understand what constitutes legal OCL syntax. Of course, we all know that 
even practical OCL grammars are permissive of strings that aren't meaningful 
(for example, 7->isEmpty() is typically legal) but more can be done than is 
expressed by the current description. I am not suggesting that you replace 
the current method of description, but that you add (perhaps only as an 
informative, non-normative appendix) a conventional grammar. The spec, after 
all, is supposed to serve the purposes of implementors. 


There are published papers describing practical grammars for OCL, or I can 
supply you with one, if you'd like. 


PS By "practical grammar" I mean one that limits the look-ahead to a finite 
number wherever possible. It is, of course, the use of OclExpression in the 
RHS of so many productions that runs up against the infinite look-ahead 
problem, and makes the published grammar unusable by implementors.
Resolution: 
Revised Text: 
Actions taken:
November 2, 2006: received issue
Discussion: 

End of Annotations:=====
s is issue # 10439

Recommendations re ptc/2005-06-06

Recommendation: The specification would be better were it to additionally 
describe a practical grammar useful to tool implementors and persons trying 
to understand what constitutes legal OCL syntax. Of course, we all know that 
even practical OCL grammars are permissive of strings that aren't meaningful 
(for example, 7->isEmpty() is typically legal) but more can be done than is 
expressed by the current description. I am not suggesting that you replace 
the current method of description, but that you add (perhaps only as an 
informative, non-normative appendix) a conventional grammar. The spec, after 
all, is supposed to serve the purposes of implementors. 


There are published papers describing practical grammars for OCL, or I can 
supply you with one, if you'd like. 


PS By "practical grammar" I mean one that limits the look-ahead to a finite 
number wherever possible. It is, of course, the use of OclExpression in the 
RHS of so many productions that runs up against the infinite look-ahead 
problem, and makes the published grammar unusable by implementors.