• From: David Carlisle <d.p.carlisle@g...>
• To: Tim Bray <tbray@t...>
• Date: Mon, 7 Nov 2016 18:39:43 +0000

On 6 November 2016 at 20:32, Tim Bray <tbray@t...> wrote:


>  and I have never encountered an XML document which
> actually declares &lt; or &amp;
>

hmm well...

https://www.w3.org/TR/1998/REC-xml-19980210.xml

line 21 of which is

<!ENTITY lt     "<">

Technically you are right of course that this document doesn't define
&lt; (and is well formed) despite that line not meeting the
requirements as specified in the same document, as that isn't a
definition of lt as it is ignored as lt is pre-defined (by definition
in XML or in the sgml declaration for sgml) but it always seemed a
good test case (and James Clark confirmed his understanding was that
it was well formed when I queried it at the time) sadly later edits of
the xml spec have rubbed off such nice self referential tests:-)

David

• References:
  • Double escaping
    • From: Tim Bray <tbray@t...>