MCE: my currrent status

[MURATA Makoto]

Dear colleagues,

I am trying to create the MCE processing model. I have
two new observations.

First, it appears that non-understood and non-ignorable
elements under ignorable elements appear to be fine.
This is because of the below sentence in the first
note in "10.1.1  Ignorable Attribute".

  By default, an ignored element is ignored in its entirety,
  including its attributes and its content.

This is reasonable since users are not forced to enumerate all
namespaces in ignored subtrees.

Second, I have been wondering why we need @MustUnderstand.
Even if we do not have this attribute, non-understood and non-ignorable
elements will cause mismatch errors.  But I now understand.  The
point is timing.  If we have @MustUnderstand, the MCE processor
will stop when it encounters this attribute.  But if we do not
have this attribute, the MCE processor will stop only when
it encounters non-understood and non-ignorable
elements.

This is again reasonable, especially because @MustUnderstand
at the root element can prevent applications from starting useless
attempts.  But our processing model has to use the
depth-first traversal for detecting errors.


Praying for the victims of the Japan Tohoku earthquake

Makoto