lib/graph: add MutableDigraph::add_graph

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/graph/digraph.nit b/lib/graph/digraph.nit
index 7ddb5a8..e6af185 100644 (file)
--- a/lib/graph/digraph.nit
+++ b/lib/graph/digraph.nit
@@ -796,6 +796,33 @@ abstract class MutableDigraph[V: Object]
        do
                for a in arcs do add_arc(a[0], a[1])
        end
+
+       # Add all vertices and arcs from the `other` graph.
+       #
+       # ~~~
+       # var g1 = new HashDigraph[Int]
+       # var arcs1 = [[0,1], [1,2]]
+       # g1.add_arcs(arcs1)
+       # g1.add_arcs(arcs1)
+       # g1.add_vertex(3)
+       # var g2 = new HashDigraph[Int]
+       # var arcs2 = [[0,1], [1,4]]
+       # g2.add_arcs(arcs2)
+       # g2.add_vertex(5)
+       # g2.add_graph(g1)
+       # assert g2.vertices.has_exactly([0, 1, 2, 3, 4, 5])
+       # var arcs3 = [[0,1], [1,2], [1,4]]
+       # assert g2.arcs.has_exactly(arcs3)
+       # ~~~
+       fun add_graph(other: Digraph[V])
+       do
+               for v in other.vertices do
+                       add_vertex(v)
+                       for w in other.successors(v) do
+                               add_arc(v, w)
+                       end
+               end
+       end
 end
 # A directed graph represented by hash maps
 class HashDigraph[V: Object]