Alexis,

All of these points actually work in favour of XML - comments inline:

On Wed, May 13, 2009 at 4:50 PM, Alexis Richardson <alexis.richardson@gmail.com> wrote:
My 2c on this one:

* I worry that allowing users to extend the core on the wire protocol
by having something as extensible as XML, will lead them to do so in
ways that break interop

I think we all [need to] accept that users must be able to extend the protocol and in order to do so safely XML offers namespaces (among other things) - in fact we need to do the same ourselves unless we're expecting to deliver everything (billing, SLAs, monitoring, etc.) at the same time in one bundle. Most alternatives (including JSON) put everyone in a room together and still expect to be able to work out who farted when things go wrong.
 
* I want something where it is really totally bogglingly obvious when
the data deviates from the allowed format

Tightly specified XML is trivial to burn into any one of a number of schema formats (e.g. RELAX NG) and then you've got on- and off-line validators which can tell you exactly which line was broken and why. This is marvellous for debugging and was used extensively to beat the reference implementation into compliance with Atom 1.0, without having to rely on talking to another implementation which may or may not be right. Most alternatives (including JSON) have no such functionality... at least not yet.
 
I note that eg HTTP has a very narrow core for interop, but people
have come up with lots of ways to extend its usefulness by convention
eg AtomPub

You realise of course that this works because HTTP adds a small amount of structure to an arbitrary/opaque data channel? Atom does the same, just adding the bare minimum of XML structure in the process...

Sam
 
On Wed, May 13, 2009 at 3:42 PM, Richard Davies
<richard.davies@elastichosts.com> wrote:
> Decision 4: For the core wire format(s), is XML or JSON the better syntax
> ('angle brackets vs. curly brackets')
> a) XML
> b) JSON
>
> Important*: This is an independent decision from decision 3 on meta-model
>
> Perspective of myself and Alexis: No strong view. We lean towards JSON,
> since it feels easier to make a tight specification and hence to easier to
> guarantee interoperability. Tightly specified use of XML might be equally
> good.
> _______________________________________________
> occi-wg mailing list
> occi-wg@ogf.org
> http://www.ogf.org/mailman/listinfo/occi-wg
>
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