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  1. OMG Issue

OCL25 — Recommendations re ptc/2005-06-06

  • Key: OCL25-134
  • Legacy Issue Number: 10439
  • Status: open  
  • Source: NIST ( Peter Denno)
  • 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.

  • Reported: OCL 2.0 — Thu, 2 Nov 2006 05:00 GMT
  • Updated: Thu, 8 Oct 2015 14:12 GMT