Re: 3.7.4. The link element (Spec Review)

On Fri, 9 May 2008, Julian Reschke wrote:
> Ian Hickson wrote:
> > > "The type of link indicated (the relationship) is given by the value 
> > > of the rel attribute, which must be present, and must have a value 
> > > that is an unordered set of space-separated tokens."
> > > 
> > > This reads funny; how can a single instance of a set be unordered? 
> > > Unordered with respect to what ordering? (yes, I understand what it 
> > > is intended to say, but then please just state that the ordering 
> > > doesn't carry any semantics).
> > 
> > What should I call the type, if not "unordered set of space-separated 
> > tokens"?
> 
> You could call it a "set of tokens", and then go on saying that ordering 
> is irrelevant. (isn't that always the case for sets, anyway?)

I need a single term for the purposes of cross-referencing. I don't 
understand why "set of space-separated tokens whose ordering is 
irrelevant" is any better than "unordered set of space-separated tokens".

And no; the spec has ordered sets as a concept. Possibly we should rename 
them to something else. :-)


> > > "Two categories of links can be created using the link element."
> > > 
> > > I think other reviewers commented on this earlier. The way this 
> > > distinction is introduced is a bit confusing and may not be needed 
> > > at all.
> > 
> > Could you elaborate on what exactly is confusing? I'm not sure how to 
> > improve it, because I don't really know what is wrong.
> 
> I wrote this a long time ago.
> 
> Looking at it right now, I guess I was (and still am) confused because 
> of the distinction between "links to external resources" and "hyperlink 
> links".
> 
> What is it good for?

The key difference is that hyperlinks are presented to the user, and links 
to external resources are not.


> > > "One element can create multiple links (of which some might be 
> > > external resource links and some might be hyperlinks). "
> > > 
> > > How?
> > 
> > I've tried to clarify this; is it clear enough now?
> 
> So it's because of multiple rel values?

Yes.


> > > If the HTML WG thinks that support for the "Link" header, defined in 
> > > RFC2068 and dropped from RFC2616, should be mandatory in HTML5 UAs, 
> > > then I strongly recommend raising this issue on 
> > > <mailto:ietf-http-wg@w3.org>, so that the header gets considered for 
> > > re-inclusion into RFC2616bis.
> > 
> > Could I ask you to do these honours? It would be great to have someone 
> > who can coordinate with the HTTP WG.
> 
> I'm much more active in the HTTP WG, so it would probably look a bit 
> funny if I would try to make a statement on behalf of the HTML WG over 
> there :-).

I just meant in the same way as you raised XHR issues on the HTTP list. As 
you say, you're more active in the HTTP WG than I am, it would be really 
helpful for someone active in the HTTP WG to be the one to raise this.

Cheers,
-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Wednesday, 28 May 2008 12:14:14 UTC