Re: [xml-dev] Is the set of languages expressible using XML asuperset of

One consideration might be schemaless JSON versus schema-driven XML. It is a matter of convention, since XML can be written without a schema and JSON with a schema, but the conventions put pressure on XML to have a schema and JSON to not have one. The unique particle constraint, for example, would reduce the number of valid XML possibilities if the XML has a schema.

Another limitation which might be different between XML and JSON is the evolution of the document over time. Changes to the XML over time, especially if there is a need for backwards or forwards compatibility, might be differently constrained compared to JSON. Cardinality is a typical change area and neither are good with this but if a schema is included in the XML case it might increase the divergence from JSON capabilities. Growth and extension points: neither are great here either. XML schemas guide designers to build in extension points so that you can have a complex type which allows additional elements to be added over time. A key differentiator is attributes in XML which cannot be extended. XML which includes attributes can only extend an attribute to turn it from leaf to branch if it is changed from attribute to element so that it can have children.

On Sun, 23 Jan 2022 at 23:15, Roger L Costello <costello@mitre.org> wrote:

Hi Folks,

An XML language can be created to express Bookstores. Another to express network router data. Another for census data. And so forth.

The set of XML languages that has already been created is vast and diverse.

How big is the set of possible XML languages?

How big is the set of possible JSON languages?

Is the set of possible XML languages a superset of the set of possible JSON languages? If yes, would you give an example of an XML language for which there is no possible JSON language?

/Roger

_______________________________________________________________________

XML-DEV is a publicly archived, unmoderated list hosted by OASIS
to support XML implementation and development. To minimize
spam in the archives, you must subscribe before posting.

[Un]Subscribe/change address: http://www.oasis-open.org/mlmanage/
Or unsubscribe: xml-dev-unsubscribe@lists.xml.org
subscribe: xml-dev-subscribe@lists.xml.org
List archive: http://lists.xml.org/archives/xml-dev/
List Guidelines: http://www.oasis-open.org/maillists/guidelines.php