XQuery (1st edition) Examples: A Closer Look at Types

Table 11-1. Examples of effective Boolean value

Table 11-2. Examples of generic sequence types

Example	Explanation
`node()*`	A sequence of one or more nodes, or the empty sequence
`item()?`	One item (a node or an atomic value) or the empty sequence
`xs:anyAtomicType+`	A sequence of one or more atomic values (of any type)

Table 11-3. Examples of sequence types based on type name

Example	Explanation
`xs:integer`	One atomic value of type `xs:integer` (or any type derived by restriction from `xs:integer`)
`xs:integer?`	One atomic value of type `xs:integer` (or any type derived by restriction from `xs:integer`), or the empty sequence
`prod:NameType*`	A sequence of one or more atomic values of type `prod:NameType`, or the empty sequence

Table 11-4. Examples of instance of expressions

Example	Explanation
`3 instance of xs:integer`	`true`
`3 instance of xs:decimal`	`true`, because `xs:integer` is derived by restriction from `xs:decimal`
`<x>{3}</x> instance of xs:integer`	`false`, because the element node `x` is untyped, even though it happens to contain an integer
`<x>{3}</x> instance of element()`	`true`
`<x>{3}</x> instance of node()`	`true`
`<x>{3}</x> instance of item()`	`true`
`(3, 4, 5) instance of xs:integer`	`false`
`(3, 4, 5) instance of xs:integer*`	`true`
`xs:float(3) instance of xs:double`	`false`

Table 11-5. Examples of casting to xs:string and xs:untypedAtomic

Chapter 11: A closer look at types