SLAX

version 1.1;            /* All scripts start with "version" */

param $name = "Poe";    /* Script parameters with default values */

var $favorites := {     /* ":=" avoids RTFs */
    <name hidden="yes"> "Spillane";
    <name> "Doyle";     /* Creates elements and attributes */
    <name> "Poe";
}

match / {               /* A match template */
    <out> {
        /* Parameters are passed by name to templates */
        call test($elt = "author", $name);
    }
}

template test ($name, $elt = "default") {
    for $this ($favorites/name) {
        if ($name == $this && not($this/@hidden)) {
            element $elt {
                copy-of .//author[name/last == $this];
            }
        } else if ($name == $this) {
            message "Hidden: " _ $name;
        }
    }
}