Utility Module

This XQuery Module contains some utility and helper functions.

With Version 11, many functions have been removed in favor of new features of XQuery 4:

BaseX 10	XQuery 4
util:array-members	array:members
util:array-values	array:values
util:chars	fn:characters
util:duplicates	fn:duplicate-values
util:init	fn:trunk
util:intersperse	fn:intersperse
util:item	fn:items-at
util:last	fn:foot
util:map-entries	map:entries
util:map-values	map:values
util:or	$expr1 otherwise $expr2
util:replicate	fn:replicate

Conventions

All functions and errors in this module and errors are assigned to the http://basex.org/modules/util namespace, which is statically bound to the util prefix.

Conditions and Ranges

util:if

Signature	util:if( $condition as item()*, $then as item()*, $else as item()* := () ) as item()*
Summary	Alternative writing for the if/then/else expression: If the effective boolean value of $condition is true, the $then branch will be evaluated. Otherwise, $else will be evaluated. If the third argument is omitted, an empty sequence will be returned.
Examples	util:if(true(), 123, 456) returns 123. util:if(0, 'wrong!') returns an empty sequence.

util:count-within

Signature	util:count-within( $sequence as item()*, $min as xs:integer, $max as xs:integer := () ) as xs:boolean
Summary	Checks if the specified $sequence has at least $min and, optionally, at most $max items. Equivalent to: let $count := count($sequence) return $count >= $min and $count <= $max
Examples	util:count-within(('a', 'b', 'c'), 2) returns true. util:count-within((1 to 1000000000)[. < 10], 3, 6) returns true.

util:range

Signature	util:range( $sequence as item()*, $first as xs:double, $last as xs:double ) as item()*
Summary	Returns items from $sequence, starting at position $first and ending at $last. Equivalent to: subsequence($sequence, $first, $last - $first + 1)
Examples	util:range(//item, 11, 20) returns all path results from (if available) position 11 to 20.

Node Functions

util:ddo

Signature	util:ddo( $nodes as node()* ) as node()*
Summary	Returns nodes in distinct document order: duplicate nodes will be removed, and the remaining nodes will be returned in document order. As results of path expressions are brought into distinct document order before they are returned, the function is equivalent to: $nodes/self::node()

util:root

Signature	util:root( $nodes as node()* ) as document-node()*
Summary	Returns the document nodes of the specified $nodes. The path expression /abc is internally represented as util:root(.)/abc. Equivalent to: util:ddo($x ! /)

util:strip-namespaces

Signature	util:strip-namespaces( $node as node(), $prefixes as xs:string* := () ) as node()
Summary	Removes namespaces with the specified $prefixes from the supplied $node. An empty string can be supplied to remove the default namespace. If no prefixes are specified, all namespaces will be removed.
Examples	Remove all namespaces from an element and its descendants: util:strip-namespaces(<xml xmlns='uri' xmlns:prefix='uri2' prefix:name='value'><prefix:child/></xml>) (: yields :) <xml name='value'><child/></xml> Remove all default namespaces: <xml xmlns='uri1'><child xmlns='uri2'/></xml> => util:strip-namespaces('')

Errors

Code	Description
negative	The specified number is negative.

Changelog

Version 11.0

• Removed: util:array-members, util:array-values, util:chars, util:duplicates, util:init, util:intersperse, util:item, util:last, util:map-entries, util:map-values, util:replicate

Version 9.7

• Added: util:strip-namespaces
• Updated: util:count-within: Renamed from util:within.

Version 9.5

• Added: util:intersperse, util:within, util:duplicates, util:array-members, util:array-values, util:map-entries, util:map-values
• Updated: util:replicate: Third argument added.

Version 9.4

• Added: util:root

Version 9.3

• Added: util:ddo

Version 9.2

• Added: util:chars, util:init
• Updated: util:item, util:last, util:range renamed (before: util:item-at, util:item-range, util:last-from)

Version 9.1

• Added: util:if, util:or

Version 9.0

• Added: util:replicate

The Module was introduced with Version 8.5.