Type of the links in `graph`

Property definitions

	# Type of the links in `graph`
	type L: Link

lib/a_star/a_star.nit:337,2--338,13

	redef type L: WeightedLink

lib/a_star/a_star.nit:381,2--27

	redef type L: PositionedLink

lib/a_star/tests/test_a_star.nit:276,2--29