24501 2014-02-05 03:02:28 +0000 In General streamability, the maximum cardinality rule is ambiguous 2014-02-14 17:35:40 +0000 1 1 1 Unclassified XPath / XQuery / XSLT XSLT 3.0 Last Call drafts PC Windows NT CLOSED FIXED P2 normal --- 1 abel.braaksma mike abel.online cmsmcq innovimax+w3c public-qt-comments oldest_to_newest 99733 0 abel.braaksma 2014-02-05 03:02:28 +0000 Under 19.8.1 General Rules for Streamability (http://www.w3.org/TR/xslt-30/#general-streamability-rules), item 2.d.iii, we say the following: "If the posture of o is crawling and C is a function call of a function whose signature indicates a return type with a maximum cardinality of one (for example a call on head or exactly-one), then striding and the adjusted sweep of o." This rule can only be applicable to built-in functions, or potentially extension functions of which the processor knows how they can be applied. For stylesheet functions, passing a node to a function without atomizing it is not allowed. I think it is best if we simply list the group of "functions with cardinality one" to avoid confusion. 99755 1 innovimax+w3c 2014-02-05 08:27:13 +0000 function of maximum cardinality of one are function for which each call to ($x1, $x2, ...$xn) satisfies zero-or-one(f($x1, $x2, ...,$xn)) 99769 2 mike 2014-02-05 11:18:56 +0000 I think the rules do work as written, though the reason why is quite subtle. If a call to a user-defined function allows nodes, then the argument that allows nodes will have a type-determined usage of navigation; under 1(b)(iii)(B) in the GSR it will therefore have an adjusted sweep of free-ranging. Rule 2(b) therefore applies and takes precedence over 2(d)(iii). I would not be averse to a note in 2(d)(iii) that points this out. 100280 3 abel.online 2014-02-11 14:12:32 +0000 We probably need to apply this rule to both a function call and a dynamic function call, or does "function call" already entails dynamic function calls? Not sure about production rules here. 100281 4 cmsmcq 2014-02-11 14:48:17 +0000 We discussed this in Prague. The functions with arguments of usage = transmission that fall under the rule in 2(d)(iii) are: exactly-one(), head(), zero-or-one(). (Others are transmissional but have cardinality gt 1.) There was resistance to listing these in normative prose, but a note saying something like "at the time this spec was first published, the functions in question were: ..." would be OK. It might also be helpful to be more explicit about invariants known to be true when 2(d)(iii) applies: - We know we're talking about a built-in or extension function, and not a stylesheet function (stylesheet function arguments have type determined usage and don't reach this point). - We know that the operand usage is transmission. - We know it's not a dynamic function call but a static one. 100599 5 mike 2014-02-14 17:35:40 +0000 I have added a note explaining that these are the only three functions to which this rule applies (at present), and explaining why.