From ffbe617c8624986d366321578b70fe9adb72f722 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 31 Mar 2013 21:28:40 +0200
Subject: [PATCH] LazyGraph.is_dag_full, with several starting vertices

---
 lazyGraph.ml  | 7 +++++++
 lazyGraph.mli | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/lazyGraph.ml b/lazyGraph.ml
index 4fb9246b..c54f86d6 100644
--- a/lazyGraph.ml
+++ b/lazyGraph.ml
@@ -444,6 +444,13 @@ let is_dag graph v =
       | _ -> true)
     (Full.dfs_full graph (Gen.singleton v))
 
+let is_dag_full graph vs =
+  Gen.for_all
+    (function
+      | Full.MeetEdge (_, _, _, Full.EdgeBackward) -> false
+      | _ -> true)
+    (Full.dfs_full graph vs)
+
 (** Reverse the path *)
 let rev_path p =
   let rec rev acc p = match p with
diff --git a/lazyGraph.mli b/lazyGraph.mli
index b5d3a18c..21ebada1 100644
--- a/lazyGraph.mli
+++ b/lazyGraph.mli
@@ -161,6 +161,9 @@ val is_dag : ('id, _, _) t -> 'id -> bool
   (** Is the subgraph explorable from the given vertex, a Directed
       Acyclic Graph? *)
 
+val is_dag_full : ('id, _, _) t -> 'id Gen.t -> bool
+  (** Is the Graph reachable from the given vertices, a DAG? See {! is_dag} *)
+
 val rev_path : ('id, 'e) path -> ('id, 'e) path
   (** Reverse the path *)