checkpoint

[sbp.git] / src / edu / berkeley / sbp / Parser.java

diff --git a/src/edu/berkeley/sbp/Parser.java b/src/edu/berkeley/sbp/Parser.java
index 868b200..fac14b0 100644 (file)
--- a/src/edu/berkeley/sbp/Parser.java
+++ b/src/edu/berkeley/sbp/Parser.java
@@ -37,7 +37,7 @@ public abstract class Parser<T extends Token, R> {
         GSS gss = new GSS();
         Token.Location loc = input.getLocation();
         GSS.Phase current = gss.new Phase(null, input.next(), loc);
-        current.newNode(null, null, pt.start, true, null);
+        current.newNode(null, null, pt.start, true);
         for(;;) {
             loc = input.getLocation();
             GSS.Phase next = gss.new Phase(current, input.next(), loc);
@@ -128,12 +128,22 @@ public abstract class Parser<T extends Token, R> {
                     if (start0.contains(p.owner()) && p.next()==null)
                         state.accept = true;
 
-                    // FIXME: how does right-nullability interact with follow restrictions?
-                    // all right-nullable rules get a reduction [Johnstone 2000]
                     if (p.isRightNullable(cache)) {
                         Walk.Follow wf = new Walk.Follow(top.empty(), p.owner(), all_elements, cache);
                         Reduction red = new Reduction(p);
-                        state.reductions.put(wf.walk(p.owner()), red);
+
+                        Topology follow = wf.walk(p.owner());
+                        if (p.owner() instanceof Sequence.RewritingSequence &&
+                            (((Sequence.RewritingSequence)p.owner()).tag+"").equals("emailaddr")) {
+                            System.out.println("follow before: " + new edu.berkeley.sbp.misc.CharToken.CharRange(follow));
+                        }
+                        for(Position p2 = p; p2 != null && p2.element() != null; p2 = p2.next())
+                            follow = follow.intersect(new Walk.Follow(top.empty(), p2.element(), all_elements, cache).walk(p2.element()));
+                        if (p.owner() instanceof Sequence.RewritingSequence &&
+                            (((Sequence.RewritingSequence)p.owner()).tag+"").equals("emailaddr")) {
+                            System.out.println("follow after: " + new edu.berkeley.sbp.misc.CharToken.CharRange(follow));
+                        }
+                        state.reductions.put(follow, red);
                         if (wf.includesEof()) state.eofReductions.add(red);
                     }
 
@@ -142,6 +152,10 @@ public abstract class Parser<T extends Token, R> {
                     if (p.element() != null && p.element() instanceof Atom)
                         state.shifts.addAll(state.gotoSetTerminals.subset(((Atom)p.element())));
                 }
+            for(State state : all_states.values()) {
+                state.oreductions = state.reductions.optimize();
+                state.oshifts = state.shifts.optimize();
+            }
         }
 
         /** a single state in the LR table and the transitions possible from it */
@@ -179,15 +193,26 @@ public abstract class Parser<T extends Token, R> {
             private           TopologicalBag<Token,State>     shifts              = new TopologicalBag<Token,State>();
             private           boolean                         accept              = false;
 
+            private VisitableMap<Token,State> oshifts = null;
+            private VisitableMap<Token,Reduction> oreductions = null;
+
             // Interface Methods //////////////////////////////////////////////////////////////////////////////
 
-            public boolean             canShift(Token t)           { return shifts.contains(t); }
-            public Iterable<State>     getShifts(Token t)          { return shifts.get(t); }
             public boolean             isAccepting()               { return accept; }
-            public Iterable<Reduction> getReductions(Token t)      { return t==null ? eofReductions : reductions.get(t); }
-            public Iterable<Reduction> getEofReductions()          { return eofReductions; }
+
+            public boolean             canShift(Token t)           { return oshifts.contains(t); }
+            public boolean             canReduce(Token t)          { return t==null ? eofReductions.size()>0 : oreductions.contains(t); }
+
             public Iterator<Position>  iterator()                  { return hs.iterator(); }
 
+            public <B,C> void          invokeShifts(Token t, Invokable<State,B,C> irbc, B b, C c) {
+                oshifts.invoke(t, irbc, b, c);
+            }
+            public <B,C> void          invokeReductions(Token t, Invokable<Reduction,B,C> irbc, B b, C c) {
+                if (t==null) for(Reduction r : eofReductions) irbc.invoke(r, b, c);
+                else         oreductions.invoke(t, irbc, b, c);
+            }
+
             // Constructor //////////////////////////////////////////////////////////////////////////////
 
             /**
@@ -326,6 +351,7 @@ public abstract class Parser<T extends Token, R> {
             public void reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild) {
                 if (numPop<=0) throw new Error("called wrong form of reduce()");
                 int pos = numPop-1;
+                Forest old = holder[pos];
                 holder[pos] = parent.pending();
                 if (pos==0) {
                     System.arraycopy(holder, 0, position.holder, 0, holder.length);
@@ -333,23 +359,27 @@ public abstract class Parser<T extends Token, R> {
                 } else {
                     reduce(onlychild, pos-1, parent.phase());
                 }
+                holder[pos] = old;
             }
 
             // FIXME: this could be more elegant and/or cleaner and/or somewhere else
             private void reduce(GSS.Phase.Node parent, int pos, GSS.Phase target) {
+                Forest old = holder[pos];
                 holder[pos] = parent.pending();
                 if (pos==0) {
                     System.arraycopy(holder, 0, position.holder, 0, holder.length);
+                    for(int i=0; i<position.pos; i++) if (position.holder[i]==null) throw new Error("realbad");
                     Forest rex = position.rewrite(target.getLocation());
                     for(GSS.Phase.Node child : parent.parents()) finish(child, rex, target);
                 } else {
                     for(GSS.Phase.Node child : parent.parents()) reduce(child, pos-1, target);
                 }
+                holder[pos] = old;
             }
             private void finish(GSS.Phase.Node parent, Forest result, GSS.Phase target) {
                 State state = parent.state.gotoSetNonTerminals.get(position.owner());
                 if (state!=null)
-                    target.newNode(parent, result, state, numPop<=0, parent.phase());
+                    target.newNode(parent, result, state, numPop<=0);
             }
         }
     }