- From: Eric van der Vlist <vdv@dyomedea.com>
- Date: Wed, 14 Nov 2001 07:39:33 +0100
- To: Eddie Robertsson <eddie@allette.com.au>
- Cc: xmlschema-dev@w3.org
Eddie Robertsson wrote: > Eric van der Vlist wrote: > > >>Just wondering how a recursive group such as: >> >> <xs:group name="group"> >> <xs:sequence> >> <xs:element name="foo"> >> <xs:complexType> >> <xs:group ref="group" minOccurs="0"/> >> </xs:complexType> >> </xs:element> >> <xs:element name="bar" type="xs:token"/> >> </xs:sequence> >> </xs:group> >> >>may be redefine without confusion between the <xs:group ref="group"/> >>meaning "extension", the <xs:group ref="group" minOccurs="0"/> meaning >>"bogus extension" the <xs:group ref="group" minOccurs="0"/> meaning >>"reference" ??? >> > > Jeez Eric, with a sentence like that I think you just qualified to be writing > specs yourself ;-) :) > > Anyway, isn't this already covered in the spec: > > "6 Within the [children], for each <group> the appropriate case among the > following must be true: > 6.1 If it has a <group> among its contents at some level the ·actual value· > of whose ref [attribute] is the same as the ·actual value· of its own name > attribute plus target namespace, then all of the following must be true: > 6.1.1 It must have exactly one such group. > ..." > > It seems that 6.1.1 prohibits a redefinition of your above example since it > would have to groups among its contents at some level where the ref attribute > is the same as its own name. Yes, this is exactly what I meant by "confusion"! The fact to use a reference to extend a group is ambiguous and overlaps with the "normal" semantic of group references. IMO, a clean derivation method should be provided for groups... Thanks Eric > -- Rendez-vous ą Paris pour le Forum XML. http://www.technoforum.fr/Pages/forumXML01/index.html ------------------------------------------------------------------------ Eric van der Vlist http://xmlfr.org http://dyomedea.com http://xsltunit.org http://4xt.org http://examplotron.org ------------------------------------------------------------------------
Received on Wednesday, 14 November 2001 01:39:38 UTC