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Re: Rescinding the request to the HTML WG to develop a polyglot guide

From: Henry S. Thompson <ht@inf.ed.ac.uk>
Date: Thu, 06 Dec 2012 14:03:55 +0000
To: Henri Sivonen <hsivonen@iki.fi>
Cc: "www-tag\@w3.org List" <www-tag@w3.org>
Message-ID: <f5bwqwv1dmc.fsf@calexico.inf.ed.ac.uk>
Henri Sivonen <hsivonen@iki.fi> writes:

> In March 2010, the following request from the TAG was conveyed to the HTML WG:
>
>>     The W3C TAG requests there should be in TR space a document
>>     which specifies how one can create a set of bits which can
>>     be served EITHER as text/html OR as application/xhtml+xml,
>>     which will work identically in a browser in both bases.
>>     (As Sam does on his web site.)
> http://lists.w3.org/Archives/Public/public-html/2010Mar/0703.html
>
> However, subsequently, the TAG requested the creation of an HTML–XML
> Task Force (of which I was a member) and the Task Force Report
> remarked “Another line of argument suggests that even under the most
> optimistic of projections, so tiny a fraction of the web will ever be
> written in Polyglot that there's no practical benefit to pursuing it
> as a general strategy for consuming documents from the web. If you
> want to consume HTML content, use an HTML parser that produces an
> XML-compatible DOM or event stream.”
> http://www.w3.org/TR/html-xml-tf-report/

So there's a line of argument that suggests polyglot is unlikely to be
useful.  That's a matter of opinion, and hence an empirical question
going forward.  My opinion is that it will be useful, and I fully
intend to use it for virtually everything I do.

> Considering that a Task Force created at the TAG’s request identified
> a non-polyglot-based approach of feeding HTML content into XML tooling
> and the alternative is more broadly applicable than polyglot, as it
> does not require the cooperation of the originator of the content,
> would the TAG, please, consider rescinding its earlier request to the
> HTML WG (quoted above) as having been obsoleted by later findings?

Different approaches work better in different situations.  The
Polyglot spec. [3] is an attempt at a statement of fact: _if_ you
produces what it defines as *polyglot markup*, _then_ the result will

 a) be conformant HTML5 per HTML5 [1a];
 b) be well-formed XML per XML 1.0 [2];
 c) be conformant XHTML5 per HTML5 [1b];
 c) produce nearly-identical DOMs when processed as XML or HTML per
    HTML5.

Its obvious utility will be to document either intent ("my toolchain
will produce polyglot as defined in [Polyglot]") or requirement
("Input to this process *must* be *polyglot markup* as defined in
[Polyglot]").  In either case it makes sense for the spec. itself to
consist largely of normative content, in the form of a definition of
polyglot markup, per case (2) of my previous message on the subject
[4].

There is no suggestion in [3] that anyone _should_ produce polyglot
markup, or that it is somehow preferrable to non-polyglot.  It exists
to meet a requirement -- the fact that you and some others, or even
many others, don't have that requirement doesn't mean that the
requirement doesn't exist.  As such it makes sense, on the usual
grounds of avoiding duplication of effort and promoting
interoperability with respect to a requirement on W3C technology, that
the W3C issue a Recommendation addressing that requirement.

REC-track requires Working Group consensus, in this case that the
definition is accurate, provides for wide review and implies an
ongoing obligation of maintenance.  Note that for _definitional_
specifications such as this one progressing to REC does _not_ require
implementation, since it is only referring specifications/documents
which may include implementable conformance requirements involving
the definition(s) provided.

ht

[1a] http://dev.w3.org/html5/spec/single-page.html#syntax
[1b] http://dev.w3.org/html5/spec/single-page.html#the-xhtml-syntax
[2] http://www.w3.org/TR/xml/
[3] http://www.w3.org/TR/html-polyglot/
[4] http://lists.w3.org/Archives/Public/www-tag/2012Dec/0035.html
-- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
                       URL: http://www.ltg.ed.ac.uk/~ht/
 [mail from me _always_ has a .sig like this -- mail without it is forged spam]
Received on Thursday, 6 December 2012 14:04:41 GMT

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