Changes

$seq input as item()+, $f action as function(item()* , item()) as item()*

$pred predicate as function(item()*)as xs:boolean, $f action as function(item()*)as item()*, $start zero as item()*

|Applies the predicate function {{Code|$predpredicate}} to {{Code|$startzero}}. If the result is {{Code|false}}, {{Code|$faction}} is invoked with the start value – or, subsequently, with the result of this function – until the predicate function returns {{Code|true()}}.

$seq input as item()*, $start zero as item()*, $f action as function(item()* , item()) as item()*

declare function hof:scan-left($seqinput, $acc, $faction) { if(empty($seqinput)) then $acc else (

hof:scan-left(tail($seqinput), $faction($acc, head($seqinput)), $faction)

$seq input as item()*, $pred predicate as function(item())

|The function returns items of <code>$seqinput</code> as long as the predicate <code>$predpredicate</code> is satisfied. It is equivalent to:

declare function hof:take-while($seqinput, $predpredicate) { if(empty($seqinput) or not($predpredicate(head($seqinput)))) then () else ( head($seqinput), hof:take-while(tail($seqinput), $predpredicate)

$seq input as item()* $pred predicate as function(item()*)as xs:boolean

|The function skips all items of <code>$seqinput</code> until the predicate <code>$predpredicate</code> is not satisfied anymore. It is equivalent to:

declare function hof:drop-while($seqinput, $predpredicate) { if($predpredicate(head($seqinput))) then ( hof:drop-while(tail($seqinput), $predpredicate)

$seqinput

$seq input as item()* $sort-key as function(item()) as item() $k as xs:integer

|Returns the {{Code|$k}} items in {{Code|$seqinput}} that are greatest when sorted by the result of {{Code|$fkey}} applied to the item. The function is a much more efficient implementation of the following scheme:

(for $x item in $seqinput order by $sort-key($xitem) descending return $xitem

$seq input as item()* $lt comparator as function(item() , item()) as xs:boolean $k as xs:integer

|Returns the {{Code|$k}} items in {{Code|$seqinput}} that are greatest when sorted in the order of the ''less-than'' predicate {{Code|$ltcomparator}}. The function is a general version of {{CodeFunction||hof:top-k-by($seq, $sort-key, $k)}}.

$expr input as item()*

|Returns its argument unchanged. This function isn’t useful on its own, but can be used as an argument to other higher-order functions.

$expr input as item()*, $ignored ignore as item()*

|Returns its first argument unchanged and ignores the second. This function isn’t useful on its own, but can be used as argument to other higher-order functions, e.g. , when a function combining two values is expected and one only wants to retain the left one.