Links that refer to a range of text, not just a point.

davis@willow.tc.cornell.edu (Jim Davis)
Date: Wed, 24 Jun 92 12:00:50 EDT
From: davis@willow.tc.cornell.edu (Jim Davis)
Message-id: <9206241600.AA13167@willow.tc.cornell.edu>
To: www-talk@nxoc01.cern.ch
Subject: Links that refer to a range of text, not just a point.
In my last piece of mail (I hope they arrive in order) I tried to
generalize replacement and expansion links.  But this way of
describing links presupposes that links have a range in the source
document.  You need this (or is this obvious?) e.g. because you must
know whether an annotation applies to the entire document, a section,
or just one word.  Likewise for replacements, you need to know how
much to replace.

But as far as I know, in most (all?) hypertext systems, the origin and
destination of links are points.  Certainly this is true in WWW, e.g.
The destination of a link is a position in a document, never a section
of a document.  On the other hand, in some sense WWW's Anchors do label
a region of the origin, since the anchor has an explicit beginning
and end.

But then this raises another issue: does WWW allow anchors within
anchors?  I think not - in which case I could not use WWW anchors to
both label a paragraph (e.g. for attaching an annotation) and a word
within it (e.g. for definition).  This worries me quite a bit.  Nor
can I attach multiple links to the same point (e.g. definitions of a
word in multiple languages).