Re: [xml-dev] Is the set of languages expressible using XML asuperset of the set of languages expressible using JSON?
It is always possible to model anything by adding a layer of interpretation. So you can say that an XML element X is an array by deeming all X elements so. And you can say that a JSON string field with name "comment" is a comment by deeming it so.
But that is just cheating, it avoids the question of what is intrinsic without any extra layer of interpretation.
So here is an XML document for which there is no JSON equivalent, without conjuring up a magic extra layer of interpretation:
<z>
<!-- Hi -->
<x>Hi</x>
<y>Hi</>
</z>
The XML has a comment and elements x and y, and x and y have the same intrinsic role or status or information type as each other but not the comment.
If you wanted to make XML more markuppy (rather than more data-typey) you would increase the number of delimiters that tags can use, and so distinguish (pre-classify) more roles/status/lifecycle structures. For example define tags as only
< symbol* [^<]* symbol* >
to allow more than just start and end tags, PIs, Comnents, declarations etc.
Rick
Regards
Rick
