Re: Mixed vs. element content (Was Re: RS/RE, again (sorry))

> From: "W. Eliot Kimber" <eliot@isogen.com>
> . . .
> There are two levels of abstraction that we usually work with: 
> 1. The immediate result of parsing.  
> 2. The result of applying application-specific semantics to the
>    results of parsing.
> Abstraction (1) is what HyTime and DSSSL call the "SGML document grove" or
> the "pGrove" (for parse grove).  What can occur in this grove is completely
> defined by the SGML property set (published in the DSSSL standard and soon
> to be published again in the HyTime TC) and reflects simply applying the
> SGML parsing rules to the input document.  It is roughly equivalent to
> "ESIS" except that the grove may be more complete and you have a formal way
> to say what you want to be in the grove (the "grove plan").
> Abstraction (2) is what HyTime calls the "extended SGML document grove", or
> "epGrove".  This is a new grove with HyTime-specific semantics applied.  It
> uses the same propery set as the first but may either suppress or remove
> some things or may modify the content to reflect HyTime-specific semantics.
> Any application is free to create it's own extended document grove.  XML
> processors will, presumably, provide their own XML-specific extended
> document groves to reflect XML-specific semantics (for example, that
> whitespace is collapsed when the -xml-space attribute is in effect).
> . . .
> Any location addressing applied against XML documents would, presumably, be
> applied against the XML epGrove (or possibly a location-method-specific
> grove derived from the epGrove), not against the pGrove.
> . . .

In terms of Eliot's enlightening discussion, I would state my feelings
as follows:  I would like to define well-formed XML so that the pGrove
for any well-formed XML is equivalent to the epGrove against which we
apply our location addressing.  I'd like to avoid introducing an
application-specific epGrove in between well-formed XML and addressing
into that well-formed XML document.