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- Date: Tue, 25 Jan 2011 20:43:53 +0000
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http://www.w3.org/Bugs/Public/show_bug.cgi?id=11095 --- Comment #3 from Jonathan Robie <jonathan.robie@redhat.com> 2011-01-25 20:43:52 UTC --- We already define the term Data Model Schema, which is currently used only for consistency constraints. We can expand the definition to include atomic types: * Definition: Data Model Schema [Definition: For a given node <add>or atomic value</add> in an XDM instance, the data model schema is defined as the schema from which the type annotation of that node was derived.] For a node <add>or atomic value</add> that was constructed by some process other than schema validation, the data model schema consists simply of the schema type definition that is represented by the type annotation <del>of the node</del>. We can then use this concept to extend derives-from() in SequenceType matching, saying that the Actual Type is a definition in the Data Model Schema, and the Expected Type is a definition in S: * SequenceType Matching The definition of SequenceType matching relies on a pseudo-function named derives-from( AT, ET ), which takes an actual simple or complex schema type AT <add>from a data model schema</add> and an expected simple or complex schema type ET <add="alt2">from S</add>, and either returns a boolean value or raises a type error [err:XPTY0004]. This function is defined as follows: # derives-from( AT, ET ) raises a type error [err:XPTY0004] if ET is not present in S. If AT is not present in S, derives-from( AT, ET ) returns derives-from(gcd(AT), ET), where gcd(AT) is the most specific base type of AT in the data model schema that is present in S. If we go this route, I would be inclined to require an error if the schemas in S are not consistent, instead of merely allowing one: * Composing S This determination is done by reference to a schema S (that is, a set of schema components). This schema S is the union of: 1. the in-scope schema definitions in the static context of the module. 2. potentially, the schema used for validating the instance document; whether a processor adds this schema to S is implementation-defined. 3. potentially, further schema components that have been made available to the processor in an implementation-defined way. A type error [err:XPTY0004] <del>may</del><add>must</add> be raised if this union does not constitute a valid schema (for example, if there are conflicts between types present in the static context and types used dynamically for validating instances.) -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug.
Received on Tuesday, 25 January 2011 20:43:55 UTC