schema ambiguity in core and matches

["Tom Comerford" <tom@supratext.com>]

Element references in the following three element definitions are syntactically ambiguous within the XML schema language:

 

element definition for xlf:group

references:

                mda:metadata

                slr:data

                val:validation

 

element definition for xlf:unit

references:

                mtc:matches

                gls:glossary

                mda:metadata

                res:resourceData

                slr:data

                val:validation

 

element definition for mtc:match

references:

                xlf:originalData

                mda:metadata

 

Each element reference is optional in the given context. In all three element definitions these references are followed by <xs:any>, which allows any element from any namespace, including any of the referenced elements. This redundancy is explicable; the element references show implementers how those elements can be used. It’s also exemplary, by which I mean to suggest that they could as easily be shown in examples and/or in the prose descriptions of how the respective elements can be used.

 

The reason that they SHOULD be in the documentation, and MUST NOT be in the schema, is this: A validating parser cannot unambiguously determine whether any occurrence of the referenced element satisfies the explicit reference, or the wild-card <xs:any> token. Thus, strict validation of the schema fails.

 

 

 

Tom Comerford
tom@supratext.com

+1 856 787 9090

 

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