X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=ac34264b3a527fe16c9fb6790ab802e4aab2840d;hb=3473141880127c6aa52d094d51739e5eb67f1703;hp=d8f39fd860301538c3eee496144f19564f9ad6e6;hpb=aeae43c3255b14e4ba65e0171b87c48bbf953c31;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index d8f39fd..ac34264 100644
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -87,7 +87,7 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     // Position //////////////////////////////////////////////////////////////////////////////
 
     /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
-    public class Position {
+    public class Position implements IntegerMappable {
 
         private Forest zero = null;
         public Forest zero() {
@@ -151,8 +151,10 @@ public abstract class Sequence extends Element implements Iterable<Element> {
             ret.append("}>");
             return ret.toString();
         }
+        private final int idx = master_position_idx++;
+        public int toInt() { return idx; }
     }
-
+    private static int master_position_idx = 0;
 
     // toString //////////////////////////////////////////////////////////////////////////////