29890 2016-10-03 09:55:08 +0000 [SER31] Arrays in sequence normalization 2016-10-07 13:28:03 +0000 1 1 1 Unclassified XPath / XQuery / XSLT Serialization 3.1 Candidate Recommendation PC Windows NT RESOLVED FIXED P2 normal --- 1 tim cmsmcq andrew_coleman public-qt-comments oldest_to_newest 127625 0 tim 2016-10-03 09:55:08 +0000 Consider document { [1] } The content expression of a document node constructor is processed in exactly the same way as an enclosed expression in the content of a direct element constructor, as described in Step 1e of 3.9.1.3 Content. In XQ31 3.9.1.3 Content, point 1.e.i. we read: "Each array returned by the enclosed expression is flattened by calling the function array:flatten() before the steps that follow." So this is equivalent to document { 1 } which can be serialized. Now compare with [1] In SER31, 2 Sequence Normalization, we read: "Where the process of converting the input sequence to a normalized sequence indicates that a value MUST be cast to xs:string, that operation is defined in Section 19.1.1 Casting to xs:string and xs:untypedAtomic FO31 of [XQuery and XPath Functions and Operators 3.1]. Where a step in the sequence normalization process indicates that a node should be copied, the copy is performed in the same way as an XSLT xsl:copy-of instruction that has a validation attribute whose value is preserve and has a select attribute whose effective value is the node, as described in Section 11.9.2 Deep Copy XT30 of [XSL Transformations (XSLT) Version 3.0], or equivalently in the same way as an XQuery content expression as described in Step 1e of Section 3.9.1.3 Content XQ31 of [XQuery 3.1: An XML Query Language], where the construction mode is preserve." This refers to Step 1e, but this is only invoked when copying nodes, not function items. So it would appear that [1] cannot be serialized, because the array flattening doesn't occur. If I'm correct, I think this marks the first time that serialization of document { E } and E behave differently under serialization (other than in error code). Was this intentional? 127700 1 andrew_coleman 2016-10-07 13:28:03 +0000 At the meeting on 2016-10-04, the WG agreed to resolve this by adding the sentence "Each item in the sequence that is an array is flattened by calling the function array:flatten() before being copied." to the end of section 2 (Sequence Normalization) bullet 1. Action A-656-02 was opened to track this