Issue 1680:  Use of lexical components (notif_service-rtf)
Source:  (, )
Nature:  Revision
Severity: 
Summary: Summary: Firstly, due to the use of lexical components such as "and", "or",
 "not", etc., the grammar is not context free. A backslash (I assume the
 syntactic category <CompEsc> is a backslash) is used to distinguish
 runtime variables from symbol names, and this is enough to ensure that
 any symbol subsequent to "\" is treated as an <Ident>.
 
 However, the <CompDot> lexical category doesn"t provide for an escaped
 <Ident>. However, I believe the following is legal IDL:
 
 struct A {
     long and;
 };
 
 This leads to a situation where a constraint such as:
 
 $.A.and == 34
 
 must be regarded as syntactically incorrect for the grammar to remain
 context free.
 
 I believe that the issue can be resolved without ambiguity by extending
 <CompDot> to allow a backslash followed by a <CompIdent>.
 

Resolution: 
Revised Text: 
Actions taken:
July 15, 1998: received issue
February 23, 1999: closed issue
Discussion: 

End of Annotations:=====
Return-Path: <briggs@dstc.edu.au>
Date: Wed, 15 Jul 1998 10:24:56 +1000
From: briggs <briggs@dstc.edu.au>
Organization: DSTC Pty Ltd
To: issues@omg.org
CC: notification@dstc.edu.au, briggs@dstc.edu.au
Subject: Notification Service Issues

Hello everyone,

I'd like to raise some issues concerning the Notification Service
constraint language.

Firstly, due to the use of lexical components such as "and", "or",
"not", etc., the grammar is not context free. A backslash (I assume
the
syntactic category <CompEsc> is a backslash) is used to distinguish
runtime variables from symbol names, and this is enough to ensure that
any symbol subsequent to '\' is treated as an <Ident>.

However, the <CompDot> lexical category doesn't provide for an escaped
<Ident>. However, I believe the following is legal IDL:

struct A {
    long and;
};

This leads to a situation where a constraint such as:

$.A.and == 34

must be regarded as syntactically incorrect for the grammar to remain
context free.

I believe that the issue can be resolved without ambiguity by
extending
<CompDot> to allow a backslash followed by a <CompIdent>.

<CompDot> := \ <CompIdent> | <CompIdent> | _length | _d | _type_id |
_repos_id

The above example would then become:

$.A.\and == 34