xml-dev - Re: Unnecessary well-formedness constraint

[Rob Lugt <roblugt@bigfoot.com>]

I agree, %Fred; has no special meaning outside of the DTD and therefore
the constraint is misleading.

On a related point I would like to question why 'PEReference' appears in the
grammar at all.  By including it in a few odd places it gives the impression
that these few places are the only places where PE references are allowed.
They are, of course, permitted almost anywhere in the DTD (apart from the
handful of exclusions described in XML 1.0, 2.8).

This point certainly caught me out when I first started looking at the XML
grammar.

Regards
Rob Lugt
ElCel Technology

----- Original Message -----
From: "Elliotte Rusty Harold" <elharo@metalab.unc.edu>
To: "xml-dev" <xml-dev@xml.org>
Sent: Thursday, October 12, 2000 8:37 PM
Subject: Unnecessary well-formedness constraint


> Section 4-1 of the XML 1.0 second edition spec states:
>
>
> Well-Formedness Constraint: In DTD
> Parameter-entity references may only appear in the DTD.
>
>
> The Annotated XML spec notes that:
>
> This constraint is not actually wrong, but it is rather misleading.
> Suppose I have a parameter entity named Fred, then if the string %Fred;
> appears somewhere in the document, outside of the DTD, that's not an
> error as this suggests; it's just the string %Fred;.
>
> So my question is why is this constraint here at all? What is its
> effect? If we removed it form the spec (say in the third edition) would
> this in any way change which document are considered to be well-formed
> or valid? Would removing it give parsers any leeway they don't have now?
> Right now this seems like an unnecessary statement to me.
>
> --
> +-----------------------+------------------------+-------------------+
> | Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
> +-----------------------+------------------------+-------------------+
> |               Java I/O (O'Reilly & Associates, 1999)               |
> |            http://metalab.unc.edu/javafaq/books/javaio/            |
> |   http://www.amazon.com/exec/obidos/ISBN=1565924851/cafeaulaitA/   |
> +----------------------------------+---------------------------------+
> |  Read Cafe au Lait for Java News:  http://metalab.unc.edu/javafaq/ |
> |  Read Cafe con Leche for XML News: http://metalab.unc.edu/xml/     |
> +----------------------------------+---------------------------------+
>
>