A node-set is converted to a string by returning the
concatenation of the string-value of each of the children of the node in
the node-set that is first in document order. If the node-set is empty, an
empty string is returned.
# File lib/rexml/functions.rb, line 158
def Functions::string_value( o )
rv = ""
o.children.each { |e|
if e.node_type == :text
rv << e.to_s
elsif e.node_type == :element
rv << string_value( e )
end
}
rv
end