Re: [apps-discuss] JSON Schema considered harmful

[Dave Crocker <[e-mail]>]

On 9/20/2012 1:05 PM, Mark Nottingham wrote:
>
> On 20/09/2012, at 9:53 AM, Tim Bray <[e-mail]> wrote:
>
>> 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.
>
> +1; somebody please give this a BCP#.


In its current form, perhaps not.

On the other hand, something along this lines could provide exremely 
useful pedagogy in doing specifications work.

It would, of course, need rather more verbose discussion/justification 
of its guidance.

That is, something that says what the characteristics are of the better 
formal notation choices are and what the characteristics of the less 
better ones are.  Then describes the better choices and their enticing 
features, perhaps in terms of tradeoffs.

Then meta-points, such as "choose exactly one".  Etc.

d/

-- 
  Dave Crocker
  Brandenburg InternetWorking
  bbiw.net