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  1. OMG Issue

CORBA34 — Keyword Identifiers(03)

  • Key: CORBA34-393
  • Legacy Issue Number: 1312
  • Status: open  
  • Source: Anonymous
  • Summary:

    Summary: The Objects By Value (OBV) Specification (orbos/98-01-18) introduced
    the concept of "keyword identifiers" in an effort to avoid breaking
    existing IDL specifications. It specifies that a keyword identifier
    is a word that is treated as a keyword only when used in a keyword
    context, and is otherwise treated as a regular identifier.
    3) It allows IDL specifications that, while not unparseable, are
    highly ambiguous, especially to a human reader. For example, Jeff
    recently posted answers on how the following is to be parsed, but
    there is no way that someone reading the OBV spec would be able to
    figure out the rules he gave:

    interface public

    { ... };
    interface custom { ... }

    ;
    value safe

    { ... };

    value foo : safe { ... }

    ; // Is this legal or an error?
    value foo2 : safe safe

    { ... }

    ; // What about this?
    value foo3

    { public x; // Is this legal or an error? public public y; // What about this? custom value(); // Is this a valid operation or a syntax error? }

    ;

    While all of these constructs can all be parsed using the appropriate
    number of look-ahead tokens (by the way, the grammar is not LALR(1)
    as the OBV Spec suggests), it is hard to read and even harder to
    parse correctly. Many IDL compilers still fail to properly implement
    the name lookup rules in the existing CORBA specification, and adding
    keyword identifiers will only make that situation much worse.

  • Reported: CORBA 2.2 — Fri, 8 May 1998 04:00 GMT
  • Updated: Tue, 8 Oct 2019 18:02 GMT