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 65f3dc3..5c399cc 100644 (file)
--- a/src/edu/berkeley/sbp/Parser.java
+++ b/src/edu/berkeley/sbp/Parser.java
@@ -185,6 +185,7 @@ public abstract class Parser<T extends Token, R> {
             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 boolean             hasReductions(Token t)      { return t==null ? eofReductions.size()>0 : reductions.has(t); }
             public Iterable<Reduction> getEofReductions()          { return eofReductions; }
             public Iterator<Position>  iterator()                  { return hs.iterator(); }
 
@@ -311,49 +312,45 @@ public abstract class Parser<T extends Token, R> {
             }
             public String toString() { return "[reduce " + position + "]"; }
 
-            public Forest reduce(GSS.Phase.Node parent) {
-                if (numPop==0) return finish(parent, zero(), parent.phase());
-                return reduce(parent, numPop-1, null, parent.phase());
+            private Forest zero = null;
+            public Forest zero() {
+                if (zero != null) return zero;
+                if (numPop > 0) throw new Error();
+                return zero = position.rewrite(null);
             }
 
-            public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild) {
+            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;
                 holder[pos] = parent.pending();
-                Forest rex = null;
                 if (pos==0) {
-                    if (rex==null) {
-                        System.arraycopy(holder, 0, position.holder, 0, holder.length);
-                        rex = position.rewrite(parent.phase().getLocation());
-                    }
+                    System.arraycopy(holder, 0, position.holder, 0, holder.length);
+                    finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
+                } else {
+                    reduce(onlychild, pos-1, parent.phase());
                 }
-                return reduce(onlychild, pos-1, rex, parent.phase());
-            }
-
-            private Forest zero = null;
-            public Forest zero() {
-                if (zero != null) return zero;
-                if (numPop > 0) throw new Error();
-                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 target) {
-                if (pos<0) return finish(parent, rex, target);
+            private void reduce(GSS.Phase.Node parent, int pos, GSS.Phase target) {
                 holder[pos] = parent.pending();
-                if (pos==0 && rex==null) {
+                if (pos==0) {
                     System.arraycopy(holder, 0, position.holder, 0, holder.length);
-                    rex = position.rewrite(target.getLocation());
+                    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);
                 }
-                for(GSS.Phase.Node child : parent.parents())
-                    reduce(child, pos-1, rex, target);
-                return rex;
             }
-            private Forest finish(GSS.Phase.Node parent, Forest result, GSS.Phase target) {
+            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());
-                return result;
             }
         }
     }