XQuery 4.0

This article is part of the XQuery Portal. It provides a summary of the most important features of the XPath and XQuery Functions and Operators 4.0 W3C Editor's Draft.

Otherwise operator

$a otherwise $b

… is equivalent to …

if(exists($a)) then $a else $b

Braced if, optional else

if($a) { $b } else { $c }

if($a) { if($b) { $c } }

Arrow map operator

"The cat sat on the mat"
=> tokenize()
=!> concat(".")
=!> upper-case()
=> string-join(" ")

Numeric literals

1_048_576

0xFC00

0b111000

Abbreviated function syntax

let $inc := fn($n) { $n + 1 } return $inc(99)

… is equivalent to …

let $inc := function($n) { $n + 1 } return $inc(99)

Focus functions (arity-one)

let $inc := fn { . + 1 } return $inc(99)

fn:filter($integers, fn { . > 5 })

fn:iterate-while($number, fn { . < 100 }, fn { . * . })

Maps

20 new map functions have been added in XPath and XQuery Functions and Operators 4.0, namely

• fn:atomic-equal
• map:build
• map:contains
• map:entries
• map:entry
• map:filter
• map:find
• map:for-each
• map:get
• map:keys
• map:merge
• map:of-pairs
• map:pair
• map:pairs
• map:put
• map:remove
• map:replace
• map:size
• map:substitute
• map:values

Map functions are described in Map Module.

Arrays

30 new array functions have been added in XPath and XQuery Functions and Operators 4.0, namely

• array:append
• array:build
• array:empty
• array:exists
• array:filter
• array:flatten
• array:fold-left
• array:fold-right
• array:foot
• array:for-each
• array:for-each-pair
• array:get
• array:head
• array:index-where
• array:insert-before
• array:join
• array:members
• array:of-members
• array:put
• array:remove
• array:replace
• array:reverse
• array:size
• array:slice
• array:sort
• array:split
• array:subarray
• array:tail
• array:trunk
• array:values

Array functions are described in Array Module.

Changelog

Version 11.0

• Added otherwise operator