Re: Endtag attributes
At 3:31 PM -0400 11/9/98, Anders W. Tell wrote: > >As a part of a small R&D project Im I trying to look into the issues >of elements vs. attributes and having attributes in endtags >(im know its outside current xml standard). > >But Im having trouble finding any work being presented around >pros and cons with endtag attributes. > >Is there anyone that could point me to research /papers/discussion on >the net ? >This would help me enormously. > >Im especially interested in arguments for having endtag arguments. There is a detailed discussion of the semantics and design of attributes vs. elements in my book "The SGML FAQ Book", that you may find helpful (along with discussions of nearly every other controversial question about SGML and XML). Common practice is that attributes represent information relevant to an element as a whole -- not to a tag. And in XML, tags aren't commonly considered first-class objects: they're a syntactic way of labelling the actual objects, namely elements; so giving them their own properties seems to me a bit out of keeping with the model. Given that, it would not fit to have different attributes on the end-tag than on the start-tag. On the other hand, having the same attributes on both ends would be redundant. One argument I have heard for them was that if you had them you might be able to parse backwards. But I have never found a good occasion to do that, and if in fact you can parse XML backwards otherwise, it hardly matters whether the parser finds the attributes first or last anyway. If you allow them, you have additional semantics to define (the syntax is obviously trivial), like what it means if you have the same name (with the same or different values) on both ends of an element, etc. etc. I don't know of an analogous precedent in other languages either (though perhaps there's one out there somewhere). Thus, I think you'll find little discussion in the literature. I've seen them show up in HTML as typos. Perhaps you could describe specifically what it is you think they would be useful for..... Steven_DeRose@B...; http://www.stg.brown.edu/~sjd Visiting Chief Scientist, Scholarly Technology Group, and Adjunct Associate Professor, Brown University; Chief Scientist, Inso Corporation xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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