[
Lists Home |
Date Index |
Thread Index
]
Bob Foster <bob@objfac.com> writes:
> I'm a bit puzzled by this. I can see why he can't have a
> minOccurs/maxOccurs on the group item as specified but why not on the
> choice nested in the group. This looks legal to me and I am curious
> what processors do not accept it.
On balance the reasoning the XML Schema WG went with was roughly this:
1) Named model groups will be most useful if different references to
them can have different min/max values;
2) Allowing min/max on both references _and_ on the top level group
in the named group definition, e.g.
. . .
<xs:group ref="myGroup" minOccurs="1" maxOccurs="10"/>
. . .
<xs:group name="myGroup">
<xs:choice minOccurs="2" maxOccurs="4">
. . .
</xs:choice>
</xs:group>
would be _very_ confusing and difficult to explain;
3) So we rule out min/max on the top group in a named model group defn.
Note also that
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="e1"/>
<xs:element name="e2"/>
<xs:element name="e3"/>
</xs:choice>
means something _quite_ different from
<xs:choice>
<xs:element name="e1" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="e2" minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="e3" minOccurs="0" maxOccurs="unbounded"/>
</xs:choice>
For example, the first allows e1 e2 e1
The second does not.
ht
--
Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
Half-time member of W3C Team
2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
URL: http://www.ltg.ed.ac.uk/~ht/
[mail really from me _always_ has this .sig -- mail without it is forged spam]
|
