Re(2): SVGLists of type DOMString

Jon,

In the previous note in this thread, you wrote:

"The DOM is defined using IDL, and IDL has a thing called an Object which
is the 
implicit base class upon which all other classes/interfaces inherit. At
least that is my 
understanding. Thus, from a DOM perspective and an IDL perspective,
DOMString 
does implicitly inherit from Object ... If my analysis is  wrong, then
please correct me"

I asked for some clarification around this point from the DOM Working
Group.  Joe 
Kesselman, one of the DOM2 authors, replied:

"
>>Do DOMString and the other DOM interfaces implicitly inherit from a
>
>fundamental base type Object?

There is no such implication. IDL has been used as a notational convention.
While that IDL could theoretically be compiled and used as a DOM binding,
that is not the primary intent. In fact,there was a proposal in OMG to
develop a serious IDL binding for the DOM which would be similar to but NOT
identical to the "abstract" interface descriptions published in the spec...
in exactly the same way that any other language-specific binding is similar
to the formal description.

In particular: DOMString is explicitly intended to be a placeholder for
whatever UCS-16 string type is most appropriate for that particular
language binding.  Note that we never specify an interface for DOMString."

Thus, DOMString does not derive from Object.  Further, the DOM2 spec does
not assume
an implicit fundamental type Object.   

To bring this back to the original point, the definition of
SVGTests::requiredFeatures in 
section 4.3 is based on an invalid assumption that DOMString inherits from
an implicit 
type Object.

S.

Received on Tuesday, 8 August 2000 16:52:45 UTC