gistfile1.rb

# setup:
def setup_graph
  g = Pacer.tg
  person = g.create_vertex type: 'person' 
  print '.'
  1000.times { g.create_vertex type: 'person' }
  print '.'
  g.v.each { |v| v.add_edges_to :friend, g.v.random(rand(100)) }
  print '.'
  1000.times { g.create_vertex :type => 'product' }
  print '.'
  g.v(type: 'person').each { |person| g.v(type: 'product').random(rand(100)).each { |prod| prod.add_edges_to :rated, person, weight: rand(5) } }
  puts '.'
  [g, person]
end


groups = person.in(:rated).out(:rated).is_not(person).uniq.group.values_route(:default) { |friend| friend.in_e(:rated).lookahead { |e| e.out_v.out(:rated).is(person) }[:weight] }

# this is a special version of reduce, specifically for group routes:
groups.reduce(0, :values) { |r, v| r + v }

# or you can turn the route into a regular array of results, but then you have to use regular enumerable methods:
groups.to_a.each { |g| g.set_values(:sum, g.values.sum) }.sort_by { |g| -g.values(:sum) }.map { |g| [g.key[:name], g.values(:sum) }