- From: Stephen Buxton <Stephen.Buxton@oracle.com>
- Date: 16 Feb 04 11:49:11
- To: public-qt-comments@w3.org
- Cc:
SECTION 2.6.6: must-understand extensions Making the pragma lexically an overloading of a comment is a good idea, because an implementation that has no pragmas can simplify their grammar to treat pragmas the same as comments (ie, don't distinguish them as separate lexical categories). The same does not apply to must-understand extensions. An implementation that has no must-understand extensions must still be on the look-out for them, because encountering a must-understand extension when you have none is a syntax error. For that reason, it seems like a bad idea to make the syntax for a must-understand extension be an overloading of the comment syntax. This means that a simple implementation with neither pragmas nor must-understand extensions can not treat anything beginning with (: as a comment. Instead it is still burdened with the need to detect "(:: extension" because that is not a comment, it is a must-understand extension (and, for that implementation, a syntax error). Some other way of denoting a must-understand extension would be preferable. Some ideas are MUExtensions ::= "{:" QName ExtensionContents* ":}" MUExtensions ::= "ext" "{" QName ExtensionContents* "}" - Steve B.
Received on Monday, 16 February 2004 14:49:13 UTC