Re: Processing instructions

James Clark scripsit:

> a) normal applications, which act on the ESIS
> b) markup-sensitive applications, which act on the MSIS

I think (a) here can be divided into (a1), the content of the document,
and (a2), the embedded metadata.  PIs (and the DOCTYPE tag constitute
the latter.  They are not in the data model but are a bag on the side.

> Normal applications are everything else.  Such applications operate on
> a well-defined information set: ESIS in the SGML case or the MicroXML
> data model in the MicroXML case.  This information set is the minimum
> that the parser must provide the application.  But, more subtly,
> it's also the _maximum_ that such applications should act on.

I think that's too narrow a view, but perhaps it can be made consistent
with the "no PIs in the data model" idea: see below.

> For comments the situation is clear.  They are not part of the data
> model/ESIS.  A markup-sensitive application is expected to preserve
> them, and a normal application is expected to ignore them.

(Sidebar:  And yet they are in the XML Infoset and the XDM -- and I bet
nobody really remembers why.  Certainly I don't.)

> If PIs are not in the MicroXML data model, then that implies, in my
> view, that normal (non-markup sensitive) applications SHOULD NOT act
> on PIs.  But that is clearly not what we want. For example, we would
> want a browser to act on an xml-stylesheet PI.

Well, but a browser is an XML and HTML application, not a MicroXML
application.  Perhaps (and this would suffice for me) PIs ought to
be syntactically allowed but not addressed to MicroXML applications,
only to XML applications that are begin asked to process MicroXML.
I think that is readily reconcilable with your view of the data model.

-- 
John Cowan    http://ccil.org/~cowan    cowan@ccil.org
[T]here is a Darwinian explanation for the refusal to accept Darwin.
Given the very pessimistic conclusions about moral purpose to which his
theory drives us, and given the importance of a sense of moral purpose
in helping us cope with life, a refusal to believe Darwin's theory may
have important survival value. --Ian Johnston

Received on Thursday, 6 September 2012 05:51:20 UTC