X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FParser.java;h=d258b7870675bbd35e722d42be0c4ef456e516f6;hp=f087a05e0ea93e48d909ed04fc2e562bb7f725fd;hb=f13be78d4291906d2f4c7588567cb114f0cc3b54;hpb=e4f373b56b1cdc2c086c0b86e5ec45bad784df0e

diff --git a/src/edu/berkeley/sbp/Parser.java b/src/edu/berkeley/sbp/Parser.java
index f087a05..d258b78 100644
--- a/src/edu/berkeley/sbp/Parser.java
+++ b/src/edu/berkeley/sbp/Parser.java
@@ -311,57 +311,49 @@ public abstract class Parser<T extends Token, R> {
             }
             public String toString() { return "[reduce " + position + "]"; }
 
-            public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild, Forest rex) {
-                Forest ret = reduce(parent, numPop-1, rex, onlychild, parent.phase());
-                return ret;
+            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) {
+                if (numPop==0) return finish(parent, zero(), parent.phase());
+                return reduce(parent, numPop-1, null, parent.phase());
             }
 
             public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild) {
+                if (numPop<=0) throw new Error("called wrong form of reduce()");
                 int pos = numPop-1;
-                if (pos>=0) holder[pos] = parent.pending();
-                Forest rex = null;
+                holder[pos] = parent.pending();
                 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);
+                    return finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
                 }
-                return reduce(onlychild, pos-1, rex, 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);
+                return reduce(onlychild, pos-1, null, parent.phase());
             }
 
             // 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) {
-                    if (rex==null) {
-                        System.arraycopy(holder, 0, position.holder, 0, holder.length);
-                        rex = position.rewrite(target.getLocation());
-                    }
-                    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);
-                } else 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);
-                } else {
-                    State state = parent.state.gotoSetNonTerminals.get(position.owner());
-                    if (state!=null)
-                        target.newNode(parent, rex, state, numPop<=0, parent.phase());
+            private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, GSS.Phase target) {
+                if (pos<0) return finish(parent, rex, target);
+                holder[pos] = parent.pending();
+                if (pos==0 && rex==null) {
+                    System.arraycopy(holder, 0, position.holder, 0, holder.length);
+                    rex = position.rewrite(target.getLocation());
                 }
+                for(GSS.Phase.Node child : parent.parents())
+                    //if (pos==0) finish(parent, rex, target);
+                    //else
+                    reduce(child, pos-1, rex, target);
                 return rex;
             }
+            private Forest 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;
+            }
         }
     }