X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FUnion.java;h=9ac5e612065e9e6e2032f7dc59498fcaa2517197;hp=1d4841ff718c4aaf272a0bf83902218605458fde;hb=7fbee73b4dd985cb5b217ed297710c00fd9d7004;hpb=2f167f63aff4b6da4d82669faf2c7ada4c93be4b

diff --git a/src/edu/berkeley/sbp/Union.java b/src/edu/berkeley/sbp/Union.java
index 1d4841f..9ac5e61 100644
--- a/src/edu/berkeley/sbp/Union.java
+++ b/src/edu/berkeley/sbp/Union.java
@@ -15,8 +15,19 @@ public class Union extends Element implements Iterable<Sequence> {
     private final List<Sequence> alternatives = new ArrayList<Sequence>();
 
     public Iterator<Sequence> iterator() { return alternatives.iterator(); }
+    public boolean contains(Sequence s) { return alternatives.contains(s); }
 
-    void reachable(HashSet<Sequence.Position> h) { for(Sequence s : alternatives) s.reachable(h); }
+    Topology toAtom() {
+        if (alternatives.size()==0) throw new RuntimeException("cannot build an Atom from a Union with no productions");
+        Topology ret = null;
+        for(Sequence s : this) {
+            Topology a = s.toAtom();
+            if (ret==null) ret = a;
+            else           ret = ret.union(a);
+        }
+        if (ret==null) throw new RuntimeException("confusion on " + this);
+        return ret;
+    }
 
     /** adds an alternative */
     public void add(Sequence s) { alternatives.add(s); }