Re: [xml-dev] what's missing in XML? What's coming?

[John Cowan <cowan@mercury.ccil.org>]

David Lee scripsit:

> 1) A Standard (or well adopted convention) for Serialized XDM so that
> programs may exchange XDM in addition to XML
> 
> 2) Better support for XDM in XQuery and XSLT to allow the input 'document'
> to be any XDM value, and corresponding support in the implementations to
> portably read such data (see #1)
> 
> 3) Adoption of the JSON Data model into XDM so that XPath/XSLT/XQuery/Schema
> can be directly used on JSON data
> 
> 4) A standard/convention for JSON / XDM conversions  to allow #1 as  both
> input and output.

I think these can be all achieved with an upward-compatible extension to
JSON, adding new syntax to represent the types of XDM 3.0, since that
already has sequences and mappings.  The obvious extension is to allow
an Element Node to be represented using the syntax of an XML element:

	{"foo" = <element/>, "bar" = <simple>element</simple>}

	[<this/>, <that>, <the><other/></the>]

The same story for Comment and PI nodes:

	[<!-- here's a comment node -->, <?here is a PI/>]

Typed literals can be done as in Turtle or SPARQL:

	{"value" = "32767"^^xsd:short}

Attribute and Namespace nodes can be done thus:

	{"this" = @this = "thisval", "that" = @xmlns:foo =
	"http://example"}

Lastly, a Document node might look like a sequence preceded by the word
"document":

	document [<!-- prolog comment -->, <root/>, <!-- epilog -->]

-- 
A mosquito cried out in his pain,               John Cowan
"A chemist has poisoned my brain!"              http://www.ccil.org/~cowan
        The cause of his sorrow                 cowan@ccil.org
        Was para-dichloro-
Diphenyltrichloroethane.                                (aka DDT)