nanoc snippet for calculating "true" page parents

gistfile1.rb

def output_parent(page)
    nil == page and return nil
    page[:x_parent] and return page[:x_parent]
    (page.identifier == '/' or page.binary? or page[:is_hidden]) and return page[:x_parent] = nil
    
    path = page.path.gsub(/[^\/]*$/,'')
    
    @items.sort_by{ |i| i.path.count('/') }.reverse.each do |i|
        (i == page or i.binary? or i[:is_hidden]) and next
        if path =~ /^#{i.path.gsub(/[^\/]+$/,'')}/
            return page[:x_parent] = i
        end
    end
    raise "error finding parent" # should never reach this point
end

def output_children(page)
    nil == page and return []
    page[:x_children] and return page[:x_children]
    page.binary? and return page[:x_children] = nil
    return page[:x_children] = @items.select { |i| output_parent(i) == page }
end