[Prev][Next][Index][Thread]

Re: Relationship types



Jon Bosak wrote:
> 
> Assume that some syntax has been specified for labeling the
> relationship between link ends.  

Hmm.  Application language.

> Consider the following incomplete
> list of relationship types, lifted directly from existing proposals
> for HTML standardization:
> 
>    PARENT

Is-a

>    CHILD

Has-a

>    PREVIOUS

goto

>    NEXT

goto

>    IMPLIES

This one is neat.  It can be a pure arc, but in practice it 
is goto or gosub parameter.
 
> Is it possible to agree on a basic list of such types?

No unless you intend as HTML did, to define an application 
language.
 
> Is it useful to agree on a basic list of such types?

Utility is a characteristic of the domain of the requirements.
 
> If such a list were defined, would it be better to restrict the labels
> that could be applied to a relationship to the choices on the list, or
> would it be better to allow additional labels not on the list to be
> applied on an ad hoc basis?

No application language based on SGML contructs has succeeded in 
restricting the addition of tags or attibutes to the language unless 
it is a *dead* language.  That is why most SGML applications
interoperate 
at the level of portable, validatible files.

Has the DTD crept back into XML in a meaningful way?

len


Follow-Ups: References: