# HG changeset patch
# User blanchet
# Date 1355152804 -3600
# Node ID b00823a7445056191b9a65e9030158a0f5bd3e08
# Parent  52ec07a7f30489499920e545f94a8c8c6fd11340# Parent  75e00ff42870551870c9727a663ebad19d9dacb7
merge

diff -r 52ec07a7f304 -r b00823a74450 src/Pure/General/graph.scala
--- a/src/Pure/General/graph.scala	Mon Dec 10 13:33:06 2012 +0100
+++ b/src/Pure/General/graph.scala	Mon Dec 10 16:20:04 2012 +0100
@@ -224,17 +224,16 @@
 
   /* transitive closure and reduction */
 
-  def transitive_closure: Graph[Key, A] =
+  private def transitive_step(z: Key): Graph[Key, A] =
   {
+    val (preds, succs) = get_entry(z)._2
     var graph = this
-    for {
-      (_, (_, (preds, succs))) <- this.entries
-      x <- preds
-      y <- succs
-    } graph = graph.add_edge(x, y)
+    for (x <- preds; y <- succs) graph = graph.add_edge(x, y)
     graph
   }
 
+  def transitive_closure: Graph[Key, A] = (this /: keys)(_.transitive_step(_))
+
   def transitive_reduction_acyclic: Graph[Key, A] =
   {
     val trans = this.transitive_closure