- From: Michael Hausenblas <michael.hausenblas@deri.org>
- Date: Fri, 31 Jul 2009 09:59:38 +0100
- To: Ian Hickson <ian@hixie.ch>, Manu Sporny <msporny@digitalbazaar.com>
- CC: HTML WG <public-html@w3.org>, RDFa TF list <public-rdf-in-xhtml-tf@w3.org>
Ian, >>> For example, the use of prefixes >> >> If I understand you correctly, the use of prefixes is a "personal >> preferences based on design philosophy" disagreement that you have as >> you have yet to produce a technical problem with the use of prefixes. >> How does that feature break UAs? > > I don't understand what you mean by "break UAs". > > Prefixes are widely documented to be an antipattern in language design. > For example, see this e-mail: > > http://lists.w3.org/Archives/Member/w3c-archive/2009Jul/0125.html > > ...where I give a quite detailed analysis of why prefixes are a feature of > poor language design. With my RDFa TF and DERI AC Rep hat off I must say I don't understand this. I indeed took a look at the provided references (interesting) but fail to see the deeper problem. Let me step back. I'm not talking about prefixes/XMLNS now, but about namespaces in the sense of [1]. In my understanding *every* 'decentralised' language (be it a programming language such as Java or a markup language such as XML-based things) needs a mechanism to unambiguously assign global names to locally defined items. This is the context necessary to deal with the decentralised aspect: everyone's free to come up with a 'System' class, e.g., in Java - and you put it in your package, say. org.deri.commons.System, and hence both machines and humans know, which System class you mean. Same holds true for XML, RDF, etc. - this is IMO not poor language design, this is very clever. Can you please enlighten me what I've been missing? Maybe you're addressing a different issue as I'm thinking of, but I'd really like to understand this ... Cheers, Michael [1] http://en.wikipedia.org/wiki/Namespace -- Dr. Michael Hausenblas LiDRC - Linked Data Research Centre DERI - Digital Enterprise Research Institute NUIG - National University of Ireland, Galway Ireland, Europe Tel. +353 91 495730 http://linkeddata.deri.ie/ http://sw-app.org/about.html > From: Ian Hickson <ian@hixie.ch> > Date: Fri, 31 Jul 2009 08:23:24 +0000 (UTC) > To: Manu Sporny <msporny@digitalbazaar.com> > Cc: HTML WG <public-html@w3.org>, RDFa TF list <public-rdf-in-xhtml-tf@w3.org> > Subject: Re: Publishing a new draft (HTML5+RDFa) > Resent-From: RDFa TF list <public-rdf-in-xhtml-tf@w3.org> > Resent-Date: Fri, 31 Jul 2009 08:24:10 +0000 > > On Fri, 31 Jul 2009, Manu Sporny wrote: >>> >>> The reason microdata is in HTML5 and RDFa is not is that RDFa has >>> fundamental technical problems >> >> As has been stated numerous times, what you are claiming to be >> "technical problems" are, in fact, "personal preferences based on design >> philosophy". > > By "technical problems" I mean problems with the design, as opposed to > editorial problems. They're primarily usability issues, which are to some > extent subjective. I make no apology for having an opinion on what makes a > usable language; it's my job to have such an opinion. > > Generally speaking, my position on this topic is a straightforward one: > simpler is better. > > RDFa fails at being "simple" in a number of ways which I detailed in my > last e-mail. I consider these problems to be serious. > > >> There was a very long set of discussions that we've had that resulted in >> every demonstrable technical issue that HTML5+RDFa has, being recorded >> here: >> >> http://rdfa.info/wiki/rdfa-in-html-issues >> >> We asked that others, including you, modify the wiki page to document >> real technical problems. > > It's not my job to maintain your issues list. > > >>> For example, the use of prefixes >> >> If I understand you correctly, the use of prefixes is a "personal >> preferences based on design philosophy" disagreement that you have as >> you have yet to produce a technical problem with the use of prefixes. >> How does that feature break UAs? > > I don't understand what you mean by "break UAs". > > Prefixes are widely documented to be an antipattern in language design. > For example, see this e-mail: > > http://lists.w3.org/Archives/Member/w3c-archive/2009Jul/0125.html > > ...where I give a quite detailed analysis of why prefixes are a feature of > poor language design. > > >>> the exclusive use of URIs for identifiers >> >> Again, if I understand you correctly, the use of "URIs-as-identifiers" >> is a "personal preferences based on design philosophy" disagreement that >> you have as you have been unable to produce a technical problem with the >> use of "URIs-as-identifiers". How does that feature break UAs? > > Exclusively using URIs for identifiers is bad language design because URIs > are a poor form of identifier for many things. This is why few languages > use them as such -- for example, programming language usually use simple > tokens as identifiers. URIs are good for identifying resources with a > scheme, host, and path, but not for verbs or predicates. Using URIs for > features which they aren't suitable for doesn't break UAs, it hurts > _authors_, which is a far worse problem. > > >>> the use of rev="", the use of rel="" in a manner incompatible >>> with the rest of HTML >> >> What is the "technical problem" here? How is this breaking UAs? > > rev="" has been shown to be poorly understood by authors. > > The problems with rel="" have been discussed to death by Julian and > others, and I won't go into them here. > > >>> the overly complicated processing model >> >> Again, does this break UAs? > > It makes the language bad. That's a much bigger problem. > > >> We have more than 7 RDFa processor implementations now, so the issue >> isn't developer-oriented. > > Did you see the number of problems Google had with its RDFa documentation? > That's a sign. > > >> If you mean that it's overly-complicated for authors, then it might be >> -- but the same amorphous claim could be made for large swaths of HTML5, >> SVG and Javascript. > > It _has_ been made of SVG, yes. If you have specific part of HTML5 that > are too complex for authors, let me know, I'll fix them. I can't speak for > JavaScript, I'm not directly involved in that work. > > >> So, what exactly is the "technical problem" with the processing model? > > It's incredibly complicated. > > >>> the presence of features that aren't necessary (such as per-value data >>> typing) >> >> Again, your personal preference. There are some that would like to be >> able to assign types to data. How is this a "technical problem"? > > What is the use case for per-value data types? > > >>> the ability to include multiple name-value pairs per element. >> >> Personal preference - what "technical problem" does this create in UAs? > > It makes the language incomprehensible for authors. > > > Complexity for authors is one of my most important concerns in HTML5's > development. You can dismiss this concern as being a "personal preference" > if you like. Meanwhile, microdata is solving the same problems with orders > of magnitude less complexity. > > -- > Ian Hickson U+1047E )\._.,--....,'``. fL > http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. > Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.' >
Received on Friday, 31 July 2009 09:00:32 UTC