15807 2012-01-31 11:13:18 +0000 [XP30] 3.16.3 Cast - {variety}simple? 2012-02-15 09:15:16 +0000 1 1 1 Unclassified XPath / XQuery / XSLT XPath 3.0 Member-only Editors Drafts PC Windows NT RESOLVED FIXED https://www.w3.org/XML/Group/qtspecs/specifications/xquery-30/html/xquery-30.html#id-cast P2 normal --- 1 tim jonathan.robie jim.melton mike public-qt-comments oldest_to_newest 63395 0 tim 2012-01-31 11:13:18 +0000 The XQuery 3.0 specification states in 3.16.3 Cast "The SimpleTypeName must be the name of a type defined in the in-scope schema types, and the {variety} of the type must be simple." However, XML Schema states: "{variety} One of {atomic, list, union}. Required for all Simple Type Definitions except ·anySimpleType·, in which it is absent." i.e. {variety} doesn't include 'simple'. This also appears in 3.16.4 Castable and the appendix entry for err:XQST0052 63396 1 tim 2012-01-31 12:05:20 +0000 Also in this section, the EBNF rule [169] is reproduced, although it is not referenced in [94] or [164]. Does this indicate an error? [94] CastExpr ::= UnaryExpr ( "cast" "as" SingleType )? [164] SingleType ::= SimpleTypeName "?"? [169] AtomicOrUnionType ::= EQName 63761 2 mike 2012-02-06 16:47:29 +0000 It should say 'The SimpleTypeName must be the name of a *generalized atomic type* defined in the in-scope schema types, that is, either an atomic type or a *restricted union type*'. (Did we really end up deciding to call this class of union types "restricted union types"? I remember there was a lot of confusion about using this term for union types that do not incorporate a restriction.) 63762 3 mike 2012-02-06 16:54:57 +0000 Actually, 5(d) makes it clear that we allow casting from string/untypedAtomic to any simple type whatsoever. So (a) my comment 2 is wrong, and (b) the presence of the production AtomicOrUnionType in this section is an anachronism. We also allow casting from an instance of one of the member types of a union to the union type, and from a value that is castable to one of the member types of a union to the union type. These cases should probably be included in the list of cases in rule 5. 64082 4 jonathan.robie 2012-02-14 13:11:53 +0000 Changing to XPath 3.0, since it affects both specs. 64134 5 jonathan.robie 2012-02-15 09:15:16 +0000 (In reply to comment #0) > The XQuery 3.0 specification states in 3.16.3 Cast > > "The SimpleTypeName must be the name of a type defined in the in-scope schema > types, and the {variety} of the type must be simple." We will change "and the {variety} of the type must be simple" to "and the type must be simple". Also, we need to add these two cases to the list of allowable casts: * We allow casting from one of the members of a union to a union type. * We allow casting from a value to a union type if you can cast to any member of the union. We will also remove production 169 from that section.