Re: [apps-discuss] JSON Schema considered harmful

[SM <[e-mail]>]

Hi Tim,

[Cc to IAB.  Please drop it if the thread is willfully wild.]

At 09:53 20-09-2012, Tim Bray wrote:
>I gave a preso at IETF70 in Vancouver a few years ago which is 
>advertised as being XML-centric, but has (I think) useful things to 
>say about plain-text/binary/ASN.1/JSON/XML, and discusses about the 
>proper place of schemas: http://www.ietf.org/proceedings/70/slides/xmltut-0.pdf

I found the presentation informative.

>I believe:
>- ASN.1 has been bypassed by history and has truly horrible tooling. 
>Just don't go there.
>- If you're interchanging documents, use XML; if (much more common) 
>you're interchanging data structures, use JSON.
>- Do not use multiple syntaxes for the same protocol. Pick one of 
>XML or JSON and stick with it.
>- The most important thing in defining a protocol is good clean 
>comprehensible human-readable prose.
>- All the protocols I've ever seen have important constraints that 
>can't be expressed usefully in declarative schema languages.
>- Therefore, the next most important thing is an automated 
>validator/test-suite.
>- A schema is a nice-to-have.
>- If you're in XML and want schema-ware, use RelaxNG. For an 
>example, see RFC4287.
>- If your protocol is JSON, investment in a validator/test-suite has 
>much higher ROI than chasing schema unicorns.

It might help to have a discussion of the above as part of an IAB document.

Regards,
-sm