RE: [xml-dev] Defining an XML vocabulary: specify syntax, semantics, and

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

Excellent discussion!  I am still assimilating all that has said, but
let me summarize some of the discussion:


PURPOSE OF AN XML VOCABULARY

Encode behavior: each element has an associated behavior.  An element
is an instruction.  The data within an element may be considered to be
a parameter for the instruction.  An application that understands the
XML vocabulary will "execute each instruction."

    Example: the XSLT specification defines an XML vocabulary.
    Each element in the vocabulary is assigned a specific
    behavior. That is, the specification describes how an  
    XSLT application (processor) should behave for each element. 


Encode data: there is no behavior associated with the elements.  The
elements are simply containers for data.  Each application is free to
process the elements in any fashion.

    Example: I may define a "Book XML Vocabulary" without any 
    mandate on how an application should process a document 
    that uses the vocabulary.


This ability to encode both behavior and data reasonably directly is
one of the things that makes XML powerful.  


XML VOCABULARY SPECIFICATION

When you create an XML vocabulary, you should write a document that
defines the elements.

If the purpose of the XML vocabulary is to encode behavior then your
document should define:

    - the syntax of each element
    - the semantics of each element
    - the behavior of each element

If the purpose of the XML vocabulary is to encode data then your
document should define:

    - the syntax of each element
    - the semantics of each element


Please let me know of errors in this summary.

/Roger