X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FParser.java;h=65f3dc3e9e3f17b80be3d03950ffc9d22ddc0901;hp=f087a05e0ea93e48d909ed04fc2e562bb7f725fd;hb=b0ec1efcb13eceb539f9cd033a0d2908fc2be27a;hpb=e4f373b56b1cdc2c086c0b86e5ec45bad784df0e

diff --git a/src/edu/berkeley/sbp/Parser.java b/src/edu/berkeley/sbp/Parser.java
index f087a05..65f3dc3 100644
--- a/src/edu/berkeley/sbp/Parser.java
+++ b/src/edu/berkeley/sbp/Parser.java
@@ -311,14 +311,15 @@ 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;
+            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();
+                holder[pos] = parent.pending();
                 Forest rex = null;
                 if (pos==0) {
                     if (rex==null) {
@@ -326,7 +327,7 @@ public abstract class Parser<T extends Token, R> {
                         rex = position.rewrite(parent.phase().getLocation());
                     }
                 }
-                return reduce(onlychild, pos-1, rex, null, parent.phase());
+                return reduce(onlychild, pos-1, rex, parent.phase());
             }
 
             private Forest zero = null;
@@ -337,31 +338,23 @@ public abstract class Parser<T extends Token, R> {
             }
 
             // 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())
+                    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;
+            }
         }
     }