X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=b33279352a9a6b61c4cfd4bfa3e29629c3670e6f;hp=d25260450ef90d7ae0ad6466d69edc00026ff283;hb=888e9ccbab5f458a727c16da9d9291fd8951d909;hpb=0516ea34996c86664928ef948013b749876b87ec

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index d252604..b332793 100644
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -35,7 +35,8 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     ////////////////////////////////////////////////////////////////////////////////
 
-    public Topology noFollow() { return null; }
+    public Element noFollow = null;
+    public final Topology noFollow() { return noFollow==null ? null : noFollow.toAtom(); }
 
     Topology toAtom() {
         if (elements.length!=1) throw new RuntimeException("cannot invoke toAtom() on a Sequence with " + elements.length + " elements: " + this);
@@ -61,8 +62,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         this.firstp = new Position(0);
     }
 
-    void reachable(HashSet<Position> h) { firstp().reachable(h); }
-
     Forest epsilonForm() { return firstp().rewrite(null); }
 
     protected abstract <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args);
@@ -73,12 +72,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
     public class Position {
 
-        void reachable(HashSet<Position> h) {
-            if (h.contains(this)) return;
-            h.add(this);
-            if (element() != null) element().reachable(h);
-        }
-
                 final int      pos;
         private final Position next;
                 final Forest[] holder;