X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FParser.java;h=1afa523124cdc0de855e0180db47a41bda410daf;hp=817aea6657b66b55d0397e168326a51a42d5102d;hb=8e38701ecbc92deab21c4c224052ae128b279738;hpb=145a9cab78330e3daad06a72e914895d32a1d621

diff --git a/src/edu/berkeley/sbp/Parser.java b/src/edu/berkeley/sbp/Parser.java
index 817aea6..1afa523 100644
--- a/src/edu/berkeley/sbp/Parser.java
+++ b/src/edu/berkeley/sbp/Parser.java
@@ -312,14 +312,14 @@ public abstract class Parser<T extends Token, R> {
             public String toString() { return "[reduce " + position + "]"; }
 
             public Forest reduce(GSS.Phase.Node parent) {
-                Forest rex = numPop==0 ? zero() : null;
-                Forest ret = reduce(parent, numPop-1, rex, null, parent.phase());
-                return ret;
+                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) {
@@ -327,7 +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;
@@ -338,31 +338,29 @@ 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) {
+            private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, 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);
+                    for(GSS.Phase.Node child : parent.parents())
+                        reduce(child, pos-1, rex, 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);
+                    for(GSS.Phase.Node child : parent.parents())
+                        reduce(child, pos-1, rex, target);
                 } else {
-                    State state = parent.state.gotoSetNonTerminals.get(position.owner());
-                    if (state!=null)
-                        target.newNode(parent, rex, state, numPop<=0, parent.phase());
+                    return finish(parent, 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;
+            }
         }
     }