graph :: Digraph :: num_arcs
var g = new HashDigraph[Int] g.add_arc(0, 1) assert g.num_arcs == 1 g.add_arc(0, 1) assert g.num_arcs == 1 g.add_arc(2, 3) assert g.num_arcs == 2
# The number of arcs in this graph. # # ~~~ # var g = new HashDigraph[Int] # g.add_arc(0, 1) # assert g.num_arcs == 1 # g.add_arc(0, 1) # assert g.num_arcs == 1 # g.add_arc(2, 3) # assert g.num_arcs == 2 # ~~~ fun num_arcs: Int is abstract
redef fun num_arcs do return number_of_arcs end