X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;fp=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;h=353e2561d83d06986c7f7bdb9e45778250ab02e2;hp=bdaedca81f52d6967d3033d1c1fc4137cb1e800b;hb=972303162555284f8066047d3caead8df139afd4;hpb=c042bb0dcce5d64f09b2788b2dfb722145162d2b

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index bdaedca..353e256 100644
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -158,6 +158,14 @@ public abstract class Forest<NodeType> implements GraphViz.ToGraphViz {
         
         void gather(HashSet<Forest<NodeType>> ht) {
             touched();
+
+            // FIXME: do something more sensible here
+            if (ht.contains(this)) {
+                System.err.println("WARNING: grammar produced a circular forest\n" + this);
+                //throw new Error("grammar produced a circular forest:\n" + this);
+                return;
+            }
+
             ht.add(this);
             for(Forest<NodeType> f : hp) f.gather(ht);
         }