better tracking of locations in GSS

darcs-hash:20070420032010-5007d-0a6156137472587ef81326d97c66a8514d4e67d6.gz

diff --git a/src/edu/berkeley/sbp/GSS.java b/src/edu/berkeley/sbp/GSS.java
index 3c6beac..a726297 100644 (file)
--- a/src/edu/berkeley/sbp/GSS.java
+++ b/src/edu/berkeley/sbp/GSS.java
@@ -52,7 +52,6 @@ class GSS {
         private Phase prev;
         private Input.Location location;
         private Input.Location nextLocation;
-        private Input.Location prevLocation;
         
         private Forest forest;
 
@@ -62,13 +61,12 @@ class GSS {
             newNode(primordealResult, startState, true);
         }
         public Phase(Phase prev, Forest forest) throws ParseFailed, IOException {
-            this.prevLocation = input.getLocation();
-            this.token = (Tok)input.next();
             this.location = input.getLocation();
+            this.token = (Tok)input.next();
+            this.nextLocation = input.getLocation();
             this.prev = prev;
             this.forest = forest;
             this.pos = prev==null ? 0 : prev.pos+1;
-            this.nextLocation = input.getLocation();
             if (prev != null) prev.shift(this, forest);
             numReductions = 0;
 
@@ -112,9 +110,7 @@ class GSS {
             return true;
         }
 
-        public Input.Location getPrevLocation() { return prevLocation; }
         public Input.Location getLocation() { return location; }
-        public Input.Region getRegion() { return prevLocation.createRegion(location); }
         public Input.Location getNextLocation() { return nextLocation; }
         public boolean        isFrontier() { return hash!=null; }
 
@@ -126,8 +122,7 @@ class GSS {
                 IntPairMap<Node> h = prev.hash;
                 prev.hash = null;
                 prev.performed = null;
-                for(Node n : h)
-                    n.check();
+                for(Node n : h) n.check();
             }
             numOldNodes = hash.size();
             for(Node n : hash.values()) {
@@ -161,6 +156,10 @@ class GSS {
             for(Node n : hash) n.check();
         }
 
+        Input.Region getRegionFromThisToNext() {
+            return getLocation().createRegion(getNextLocation());
+        }
+
         void newNodeFromReduction(Result result, State state, Position reduction) {
             int pos = result.phase().pos;
             Sequence owner = reduction.owner();