X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FParser.java;h=fac14b0e78e251ff76b6f12254eb9b17cae4fce4;hp=6f1098e779a418237495c20a215257123dcba860;hb=9ded11559a1b6f817e99355b1c9e2c88042e91d4;hpb=72cc02d0f08922a98b9f2139e814b6c33b275a43

diff --git a/src/edu/berkeley/sbp/Parser.java b/src/edu/berkeley/sbp/Parser.java
index 6f1098e..fac14b0 100644
--- 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 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 //////////////////////////////////////////////////////////////////////////////
 
             /**
@@ -310,13 +335,6 @@ public abstract class Parser<T extends Token, R> {
                 this.holder = new Forest[numPop];
             }
             public String toString() { return "[reduce " + position + "]"; }
-            public Forest reduce(Forest f, GSS.Phase.Node parent, GSS.Phase.Node onlychild, GSS.Phase target, Forest rex) {
-                holder[numPop-1] = f;
-                return reduce(parent, numPop-2, rex, onlychild, target);                
-            }
-            public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild, GSS.Phase target, Forest rex) {
-                return reduce(parent, numPop-1, rex, onlychild, target);
-            }
 
             private Forest zero = null;
             public Forest zero() {
@@ -325,25 +343,43 @@ public abstract class Parser<T extends Token, R> {
                 return zero = position.rewrite(null);
             }
 
-            // FIXME: this could be more elegant and/or cleaner and/or somewhere else
-            private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, GSS.Phase.Node onlychild, GSS.Phase target) {
-                if (pos>=0) holder[pos] = parent.pending();
-                if (pos<=0 && rex==null) {
+            public void reduce(GSS.Phase.Node parent) {
+                if (numPop==0) finish(parent, zero(), parent.phase());
+                else           reduce(parent, numPop-1, parent.phase());
+            }
+
+            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);
-                    rex = position.rewrite(target.getLocation());
+                    finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
+                } else {
+                    reduce(onlychild, pos-1, parent.phase());
                 }
-                if (pos >=0) {
-                    if (onlychild != null)
-                        reduce(onlychild, pos-1, rex, null, target);
-                    else 
-                        for(GSS.Phase.Node child : parent.parents())
-                            reduce(child, pos-1, rex, null, target);
+                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 {
-                    State state = parent.state.gotoSetNonTerminals.get(position.owner());
-                    if (state!=null)
-                        target.newNode(parent, rex, state, numPop<=0, parent.phase);
+                    for(GSS.Phase.Node child : parent.parents()) reduce(child, pos-1, target);
                 }
-                return rex;
+                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);
             }
         }
     }