XQuery/Sequences Module

Motivation You want to perform a function on a sequence. You can one of the following functions: map, fold or filter. Method Here is the structure of these three functions. sequences:map($func as function, $seqA as item()*, $seqB as item()*) as item()* sequences:fold($func as function, $seq as item()*, $start as item()) sequences:filter($func as function, $seq as item()*) as item()* Each of them takes an XQuery function as the first argument. Map The map function applies the function item $f to every item from the sequence $seq in turn, returning the concatenation of the resulting sequences in order. W3C Page on Map Fold Filter