- From: Arnold, Curt <Curt.Arnold@hyprotech.com>
- Date: Wed, 8 Dec 1999 11:35:24 -0700
- To: "'www-xml-schema-comments@w3.org'" <www-xml-schema-comments@w3.org>
- Cc: "'xml-dev@ic.ac.uk'" <xml-dev@ic.ac.uk>
Sorry about the duplicate (or near duplicate) Part 1 messages. I'm not really sure how that happened. This part makes some simple modifications that greatly simplify specifying the lexical represention of data types that have several forms. Here are some productions that would be difficult to enforce without the suggested modifications.: NameTest from XPath: NameTest ::= '*' | NCName ':' '*' | QName NCName from XML Namespaces: 4] NCName ::= (Letter | '_') (NCNameChar) The SVG path data datatype (datatype of the d attribute) <path d="M 100 100 L 140 100 L 120 140 z"/> Proposal: After reviewing the current datatypes doc, I'm a little confused with what happened with the previous lexicalRepresentation element. The interpretation of pattern and lexical are not adequately discussed. I'm moving more things around than I thought that I would need to, but here goes. Here are what I think would be reasonable renderings of the previous production patterns. <datatype name="nameTest"> <basetype name="string"/> <!-- this is using the lexical element to represent all legal string encodings of nameTest for a string to be a valid nameTest one of the exclosed patterns must match and must conform to the lexical representation of the base type --> <lexical> <!-- could be just an asterisk --> <pattern>\*</pattern> <!-- matching this pattern means that it matches the namespaceWildcard datatype and the default pattern of ".*" --> <pattern datatype="namespaceWildcard"/> <pattern datatype="qname"/> </lexical> </datatype> <datatype name="namespaceWildcardFragments"> <basetype name="string"/> <lexical> <pattern datatype="ncname"/> <pattern>:</pattern> <pattern>\*</pattern> </lexical> </datatype> </datatype name="namespaceWildcard"> <basetype name="namespaceWildcardFragments"/> <list minOccur="3" maxOccur="3"/> <!-- regex constraint on entire list, making sure that the last two characters are :* -> <lexical><pattern>.*:\*</pattern></lexical> </datatype> <datatype name="qnameFragments"> <lexical> <pattern datatype="ncname"/> <pattern>:</pattern> </lexical> </datatype> <datatype name="qname"> <basetype name="qnameFragments"/> <list minOccur="1" maxOccur="3"/> <lexical> <!-- matches any two character or longer string that doesn't have an initial or final colon --> <pattern>[^:].*[^:]</pattern> <!-- matches any non-colon single character string --> <pattern>[^:]</pattern> </lexical> </datatype> <datatype name="ncname"> <basetype name="nmtoken"/> <!-- disallow colon from nmtoken --> <lexical><pattern>[^:]*</pattern> </datatype> <!-- SVG example --> <datatype name="svgcoord"> <basetype name="real"/> <list minOccur="2" maxOccur="2"/> </datatype> <datatype name="moveCommandFragment"> <basetype name="string"/> <lexical> <pattern>[Mm]</pattern> <pattern datatype="svgcoord"/> </lexical> </datatype> <datatype name="moveCommand"> <basetype name="moveCommandFragment"/> <list minOccur="2"/> <lexical> <pattern>[Mm][^Mm]*</pattern> </lexical> </datatype> ... omited for other SVG productions <datatype name="pathdataItem"> <basetype name="string"/> <lexical> <pattern datatype="moveCommand"/> <pattern datatype="curvetoCommand"/> <pattern datatype="smoothCommand"/> <pattern datatype="arcCommand"/> ... </lexical> </datatype> <datatype name="pathdata"> <basetype="pathdataItem"/> <list/> </datatype> <attribute name="d" datatype="pathdata"/>
Received on Wednesday, 8 December 1999 13:38:06 UTC