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