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FunctX XQuery Functions

functx:sequence-type

The sequence type that represents a sequence of nodes or values

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Description

The functx:sequence-type function checks the types and/or node kinds of one or more items ($items) and returns a sequence type that matches $items. This is useful for debugging and testing the composition of a sequence.

Arguments and Return Type

NameTypeDescription
$items item()* the items whose sequence type you want to determine
return value xs:string

XQuery Function Declaration

See XSLT definition.
declare namespace functx = "http://www.functx.com";
declare function functx:sequence-type
  ( $items as item()* )  as xs:string {

concat(
  if (empty($items))
  then 'empty-sequence()'
  else if (every $val in $items
           satisfies $val instance of xs:anyAtomicType)
  then if (count(distinct-values(functx:atomic-type($items)))
           > 1)
  then 'xs:anyAtomicType'
  else functx:atomic-type($items[1])
  else if (some $val in $items
           satisfies $val instance of xs:anyAtomicType)
  then 'item()'
  else if (count(distinct-values(functx:node-kind($items))) > 1)
  then 'node()'
  else concat(functx:node-kind($items[1]),'()')
  ,
  if (count($items) > 1)
  then '+' else '')
   } ;

Examples

let $in-xml :=
<in-xml>
  <a att1="y">x</a>
  <b att1="x">x</b>
  <!-- comment -->
</in-xml>
return
XQuery ExampleResultsExplanation
functx:sequence-type(2)
xs:integer
functx:sequence-type(('abc','def'))
xs:string+
functx:sequence-type(('abc',2))
xs:anyAtomicType+
functx:sequence-type( () )
empty-sequence()
functx:sequence-type($in-xml/*[1])
element()
functx:sequence-type($in-xml/*)
element()+
functx:sequence-type($in-xml/*/@*)
attribute()+
functx:sequence-type($in-xml/*/text())
text()+
functx:sequence-type($in-xml/comment())
comment()
functx:sequence-type($in-xml/node())
node()+
generic because there is a combination of node kinds (element and comment)
functx:sequence-type(($in-xml/*,'2'))
item()+
even more generic because there is a combination of nodes and an atomic value

Depends On

functx:node-kindThe XML node kind (element, attribute, text, etc.)
functx:atomic-typeThe built-in type of an atomic value

History

Published OnLast UpdatedContributor(s)
2007-08-082007-08-08Priscilla Walmsley, Datypic, pwalmsley@datypic.com, http://www.datypic.com
Datypic XQuery Services

Recommended Reading:

XQuery