W3C home > Mailing lists > Public > w3c-sgml-wg@w3.org > December 1996

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

From: Steven R. Newcomb <srn@techno.com>
Date: Mon, 23 Dec 1996 15:14:49 -0500
Message-Id: <199612232014.PAA02015@bruno.techno.com>
To: w3c-sgml-wg@www10.w3.org
> Hytime-anchor is one way to view the matter.  But to many in our target
> audience, <a name=foo> </a> is an anchor whether or not it's pointed to, 
> and it isn't a Hytime-anchor unless it is pointed to.  
> 
> 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.  

I originally wanted to call such anchors "potential anchors" but I
gave that up because everything, and every imaginable combination of
everything, is potentially an anchor.  The question hasn't come up
since, but I still think it's a valid constructional idea in general
and it's certainly an essential idea in the context of needing to
generalize starting from ordinary HTML practice.  How about
"anticipated anchor" or "author-anticipated anchor"?

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

>  - if Tim's server is down?  

Yes, because whether the server is up or down does not change the
HTML-defined semantic that this is a link which is also one of its own
anchors.  (This question seems a lot like asking whether a falling tree
makes noise if nobody hears it.  Epistemology, anyone?)

>  - if Tim removes the document?

Yes, because no matter where the document may or may not be, the HTML
semantic remains that this is a link which is also one of its own
anchors.  (The falling tree problem applies here too.)

>  - if the URL were misspelled? 

Yes, because no matter where the address leads or doesn't lead, the HTML
semantic remains that this is a link which is also one of its own
anchors.

Now let's talk about the anchor status of mprdv.html.

Assuming our application knows about the element

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

, is the file mprdv.html on Tim's server a Hytime-anchor

>  - if Tim's server is down?  

Yes.  (Too bad we can't get to it, though.  It's an offline anchor
for the moment.)

>  - if Tim removes the document?

No, because, since it is addressed in terms of its location, if there
is nothing at that location, there is nothing to confer anchor status
upon.  Wherever Tim has moved the document to, it is no longer having
anchor status conferred upon it by this link, because the address used
by this link doesn't actually refer to the document any more.

>  - if the URL were misspelled? 

No, because, since it is addressed in terms of its location, if there
is nothing at that location, there is nothing to confer anchor status
upon.  Anchor status can be conferred only upon the objects that are
actually addressed by the link.  "A miss is as good as a mile."

> 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 those bytes are the anchor of a link, and no if they're not.
The fact that they are addressed is irrelevant unless the addressing
mechanism is used by a link to confer anchor status upon those bytes.

--Steve

             Steven R. Newcomb   President
         voice +1 716 271 0796   TechnoTeacher, Inc.
           fax +1 716 271 0129   (courier: 23-2 Clover Park,
      Internet: srn@techno.com    Rochester NY 14618)
           FTP: ftp.techno.com   P.O. Box 23795
    WWW: http://www.techno.com   Rochester, NY 14692-3795 USA
Received on Monday, 23 December 1996 15:13:19 EST

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