- From: James Clark <jjc@jclark.com>
- Date: Fri, 17 Oct 2008 10:04:58 +0700
- To: xml-editor@w3.org
- Message-ID: <9e93ab770810162004r367835c8pa3adb112b822ce6f@mail.gmail.com>
I know this is rather late in the day, but I haven't been following XML specifications much recently. I would like to draw your attention to a couple of points about http://www.w3.org/TR/2008/PER-xml-20080205/ that you might not have considered: First, it still includes the definition: [Definition: A *Name* is a token beginning with a letter or one of a few > punctuation characters, and continuing with letters, digits, hyphens, > underscores, colons, or full stops, together known as name characters.] which is clearly not appropriate given the new definition of name. Second, and much more importantly, XML Namespaces 1.0 defines NCNameStartChar in terms of the XML 1.0 Letter production, which is still defined in the 5th edition as it was in the 4th Edition. This implies that, upon publication of XML 1.0 5th Edition, conformance to XML Namespaces 1.0 will require the first character of names to follow the 4th edition rules and the following characters to follow the 5th edition rules! Since most specs and parsers these days require documents to conform to both XML 1.0 and XML Namespaces 1.0, the net result in practice of the 5th edition will be that names in documents cannot take advantage of the 5th editions's expanded character repertoire. (Of course, using XML Namespaces 1.1 is not an option, because that references XML 1.1.) This second point seems to me to be illustrative of a more fundamental problem with the 5th edition. Whilst in theory people writing specs that reference XML 1.0 should have given careful consideration to whether to use a dated or a non-dated reference, and should have consistently used one or the other with a full appreciation of the potential consequences of this, in practice I do not believe this has happened. Before you guys dreamed up the 5th edition, I don't think anybody would have anticipated that the possibility of a change to the fundamental philosophy behind the selection of allowed name characters in XML without changing the version number. The result is that many specs that reference XML 1.0 aren't prepared for such a change. When you look at XML 1.0 by itself, I think there's a good case that the benefits of the 5th edition are greater than its costs, but when you consider the impact on XML 1.0 together with the whole universe of specs that are built on top of XML 1.0, I think the scales clearly tip the other way. My suggestion would be to do an XML 1.2 that changes XML 1.0 only by making the proposed 5th edition change to names, do a Namespaces 1.2 that references XML 1.2, and then deprecate XML 1.1 and XML Namespaces 1.1. I know that XML 1.1 didn't get much uptake, but I think that is partly because it also included many other changes, whose usefulness was not nearly as clear. James
Received on Friday, 17 October 2008 03:05:34 UTC