Re: anchor awareness (was Re: Richer & richer semantics?)

At 11:04 AM 12/23/96 -0800, Terry Allen wrote:

>So if we say that "anchor" means "what Hytime calls an anchor" 
>we will probably find it necessary to come up with a term 
>to describe what "anchor" presently means to many people.  It is 
>useful to have a term for anchors-the-author-provided-in-case-
>anyone-wants-to-link-to-them.  

How about "element with an ID"?

>Now is <a href="http://www.textuality.com/sgml-erb/mprdv.html">foo</a>
>a Hytime-anchor 

Which thing are you referring to?  There are two anchors here: the A
element itself and the object or objects addressed by the value of the HREF
attribute.  The A element is always an anchor because it is a contextual
link and therefore one of its own anchors.  I assume you mean the thing
addressed by the value of the HREF attribute.

The object addressed is an anchor as long as it exists (remembering that
URLs, in particular, refer to locations and not objects, so the anchor is
whatever object happens to be at that location--meaning that as long as
*something* is at that location it will be the other anchor of the above
link--this is where the subtle distinction between locations and names
raised in the URL/URN discussion comes into play--in SGML it's the
difference between addressing an entity only by system identifier and
addressing it initially by public identifier, or addressing a book by ISBN
or by physical location on the shelf.)

> - if Tim's server is down?  

Yes, assuming the object still exists at the specified address.

> - if Tim removes the document?

No, assuming he doesn't put anything else at the same location.

> - if the URL were misspelled? 

Depends on whether or not the URL still addresses something.  If it does,
that thing is the anchor.  If not, there's no anchor and you have a broken
link in this case.

>And if byte range 1001--2001 in that document can be addressed, is that 
>byte range (not distinguished by anything in the document itself) an 
>anchor?

Yes, if it is actually addressed by a hyperlink.

Cheers,

E.
--
W. Eliot Kimber (eliot@isogen.com) 
Senior SGML Consulting Engineer, Highland Consulting
2200 North Lamar Street, Suite 230, Dallas, Texas 75202
+1-214-953-0004 +1-214-953-3152 fax
http://www.isogen.com (work) http://www.drmacro.com (home)
"Rats in the morning, rats in the afternoon...if they don't go away, I'll be
re-educated soon..."                 --Austin Lounge Lizards, "1984 Blues"

Received on Monday, 23 December 1996 15:03:55 UTC