29963 2016-10-30 15:40:25 +0000 [FO31] Relation item type vs list types 2016-12-16 19:55:27 +0000 1 1 1 Unclassified XPath / XQuery / XSLT Functions and Operators 3.1 Candidate Recommendation PC Windows NT CLOSED FIXED P2 normal --- 1 abel.braaksma mike josh.spiegel public-qt-comments oldest_to_newest 127980 0 abel.braaksma 2016-10-30 15:40:25 +0000 (part of the series of issues on FO31 review) The section 1.6 on the type system does not make clear what the relation is between item and list types. In particular, the first diagram starts with item, and has xs:anyAtomicType as a descendant. The second diagram also has xs:anyAtomicType in it, with xs:anySimpleType as parent. You may deduce from this that item == xs:anySimpleType, or more indirectly, item is a parent (and therefore an instance of) list types, but I doubt that is the intent. I have to admit I am not sure how this could be drawn differently, perhaps a note that explains the relation between diagram 1 and 2 better? 127981 1 mike 2016-10-30 18:19:03 +0000 F+O merely copies these diagrams from the Data Model spec. There is no relation between item types and list types, other than the fact that both (unfortunately) use the same word "type" in their names. Item types fit into the hierarchy rooted at item(), which is defined in XDM, while list types fit into the hierarchy rooted at xs:anyType, which is defined in XSD. Comparing the two is a category error. We've made good progress in separating the concepts since XDM 1.0, which attempted to show both hierarchies on a single diagram. 127991 2 mike 2016-10-31 23:30:26 +0000 Reclassified as F+O 3.1. 128000 3 josh.spiegel 2016-11-01 15:35:05 +0000 The introduction sentence calls out that the type system comprises two distinct subsystems that both include primitive atomic types. Mike will try to restructure the section to help clarify this. I am closing the bug but feel free to reopen with suggestions on further clarifications that you think would be helpful. 128007 4 abel.braaksma 2016-11-01 16:11:15 +0000 Seems reasonable, tx.