Re: [xml-dev] Designing an XML Vocabulary: The First Two Questions

[Jonathan Robie <jonathan.robie@redhat.com>]

Costello, Roger L. wrote:
> Hi Folks,
>
> Based on our recent discussions, I have arrived at "The First Two
> Questions."  Comments welcome.  /Roger
>
>
> THE FIRST TWO QUESTIONS
>
> 1. Is the purpose of the XML vocabulary to encode behavior or to encode
> data?
>   

This is a little like the document/data distinction that some people try 
to make. On a broad intuitive level it makes sense for some 
applications, but there is a lot of gray. Consider the following:

Ant files - do they describe dependencies, or should we think of them as 
instructions for a build process?
XProc - see above.
XML Schema - does it describe a schema, or does it describe how 
validation and PSVI construction should be done?
Stock transactions - is the message a command, or data that is being 
transferred?

To me, the distinction between data and behavior is not that clear cut.

> 2. Is the purpose of the XML vocabulary to markup one specific kind of
> data, or to markup multiple diverse kinds of data?
>   

Again, I find this fuzzy.

I assume you would see HTML or DocBook as vocabularies designed for 
"multiple diverse kinds of data", or are they two vocabularies each 
designed for one specific kind of data, web pages and technical 
documentation respectively?

> (a) Creating a new XML vocabulary is a last resort.  Use an existing
> one if possible.
>   

I disagree. A lot of this boils down to how comfortable you are writing 
XML vocabularies, whether you prefer vocabularies designed for specific 
needs, how you create the markup, etc.

Jonathan