From 475743c156fc5b02e79cd787b3176f5fa1877f83 Mon Sep 17 00:00:00 2001
From: adam <adam@megacz.com>
Date: Mon, 30 Jan 2006 02:33:36 -0500
Subject: [PATCH] checkpoint

darcs-hash:20060130073336-5007d-4ec1424159f3c6a89e15c20a415e9dfec5f48f68.gz
---
 src/edu/berkeley/sbp/misc/MetaGrammar.java |  158 ++++++++++++++--------------
 tests/meta.g                               |   10 +-
 2 files changed, 83 insertions(+), 85 deletions(-)

diff --git a/src/edu/berkeley/sbp/misc/MetaGrammar.java b/src/edu/berkeley/sbp/misc/MetaGrammar.java
index b1de3b1..e983a3d 100644
--- a/src/edu/berkeley/sbp/misc/MetaGrammar.java
+++ b/src/edu/berkeley/sbp/misc/MetaGrammar.java
@@ -125,6 +125,7 @@ public class MetaGrammar extends StringWalker {
         else if ("?".equals(head))   return Repeat.maybe((Element)walk(tree.child(0)));
         else if ("!".equals(head))   { Element e = (Element)walk(tree.child(0)); dropAll.add(e); return e; }
         else if ("&".equals(head))   return ((Sequence)walk(tree,0)).and(sequence(walk(tree, 1), true));
+        else if ("and".equals(head)) return ((Sequence)walk(tree,0)).and(sequence(walk(tree, 1), true));
         else if ("&~".equals(head))  return ((Sequence)walk(tree,0)).not(sequence(walk(tree, 1), true));
         else if ("epsilon".equals(head)) return Union.epsilon;
         else if ("()".equals(head)) return Union.epsilon;
@@ -151,8 +152,10 @@ public class MetaGrammar extends StringWalker {
         else if ("/".equals(head)) return ((PreSequence)walk(tree, 0)).sparse((Element)walk(tree, 1));
         else if ("~".equals(head)) return new Hack(new Atom.Invert(new Atom.Infer((Element)walk(tree, 0))));
         else if ("ps".equals(head)) return new PreSequence((Object[])walk(tree,0), null);
-        else if (":".equals(head)) return new PreSequence(new Object[] { walk(tree, 1) }, convertLabel(string(tree.child(0)))).buildUnion();
-        else if ("::".equals(head)) {
+        else if (":".equals(head)) {
+            String s = string(tree.child(0));
+            return new Keep("_".equals(s)?walk(tree,1):new PreSequence(new Object[] { walk(tree, 1) }, convertLabel(s)).buildUnion());
+        } else if ("::".equals(head)) {
             PreSequence p = (PreSequence)walk(tree, 1);
             p.tag = convertLabel(string(tree.child(0)));
             return p;
@@ -260,12 +263,19 @@ public class MetaGrammar extends StringWalker {
             HashSet<Sequence> set = new HashSet<Sequence>();
             Element[] o2 = o==null ? new Element[0] : new Element[o.length];
             int nonDrop = 0;
-            int keeping = -1;
+            boolean keeping = false;
             if (o != null) {
                 int j = 0;
                 for(int i=0; i<o.length; i++) {
                     Object oi = o[i];
-                    if (oi instanceof Keep)    { keeping = j; oi = ((Keep)oi).o; }
+                    if (oi instanceof Keep)    {
+                        if (!keeping) { for(int k=0; k<i; k++) drops[k]=true; }
+                        drops[i] = false;
+                        keeping = true;
+                        oi = ((Keep)oi).o;
+                    } else {
+                        if (keeping) drops[i] = true;
+                    }
                     if (oi==SELF)                    o2[j] = u.new Subset("(("+u+"))", set);
                     else                             o2[j] = (Element)oi;
 
@@ -284,14 +294,10 @@ public class MetaGrammar extends StringWalker {
             else if (tag!=null) ret = Sequence.rewritingSequence(tag, expansion, drops);
             else {
                 int idx = -1;
-                if (keeping != -1) {
-                    idx = keeping;
-                } else {
-                    for(int i=0; i<expansion.length; i++)
-                        if (!drops[i])
-                            if (idx==-1) idx = i;
-                            else throw new Error("multiple non-dropped elements in sequence: " + Sequence.drop(expansion,false));
-                }
+                for(int i=0; i<expansion.length; i++)
+                    if (!drops[i])
+                        if (idx==-1) idx = i;
+                        else throw new Error("multiple non-dropped elements in sequence: " + Sequence.drop(expansion,false));
                 if (idx != -1) ret = Sequence.singleton(expansion, idx);
                 else           ret = Sequence.drop(expansion, false);
             }
@@ -468,23 +474,26 @@ public class MetaGrammar extends StringWalker {
 
 
 
+
+
+
         // DO NOT EDIT STUFF BELOW: IT IS AUTOMATICALLY GENERATED
 new edu.berkeley.sbp.Tree(null, "gram", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "grammar", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "=", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })}),
-        new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "::", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "g", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, ":", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "g", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "r", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "a", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { })}),
-        new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})}),
         new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "G", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "r", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "a", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "a", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "r", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, "r", new edu.berkeley.sbp.Tree[] { })})})}),
         new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})})})})})})}),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})})})})})}),
         new edu.berkeley.sbp.Tree(null, "=", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "G", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "r", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "a", new edu.berkeley.sbp.Tree[] { }),
@@ -538,15 +547,14 @@ new edu.berkeley.sbp.Tree(null, "gram", new edu.berkeley.sbp.Tree[] { new edu.be
         new edu.berkeley.sbp.Tree(null, "=", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "R", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "H", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { })}),
-        new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "+/", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "(", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "+/", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "C", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "o", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "j", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "+/", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "(", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "+/", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "q", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "t", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})}),
         new edu.berkeley.sbp.Tree(null, "(", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})}),
         new edu.berkeley.sbp.Tree(null, "literal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "|", new edu.berkeley.sbp.Tree[] { })})}),
@@ -557,62 +565,6 @@ new edu.berkeley.sbp.Tree(null, "gram", new edu.berkeley.sbp.Tree[] { new edu.be
         new edu.berkeley.sbp.Tree(null, "literal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, ">", new edu.berkeley.sbp.Tree[] { })})}),
         new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})})})})})})})})})})})})})}),
-        new edu.berkeley.sbp.Tree(null, "=", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "C", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "o", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "j", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "t", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })}),
-        new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "q", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})})})})}),
-        new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "/", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "q", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})}),
-        new edu.berkeley.sbp.Tree(null, "^", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "&", new edu.berkeley.sbp.Tree[] { })})}),
-        new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "E", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "l", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "t", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})}),
-        new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})}),
-        new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "/", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "q", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})}),
-        new edu.berkeley.sbp.Tree(null, "^", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "&", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "~", new edu.berkeley.sbp.Tree[] { })})}),
-        new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "E", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "l", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "t", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})}),
-        new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})})})})}),
         new edu.berkeley.sbp.Tree(null, "=", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "E", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "l", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
@@ -724,7 +676,50 @@ new edu.berkeley.sbp.Tree(null, "gram", new edu.berkeley.sbp.Tree[] { new edu.be
         new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
-        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})})})})})})})})}),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})})})})})}),
+        new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "q", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})}),
+        new edu.berkeley.sbp.Tree(null, "^", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "&", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})}),
+        new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "E", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "l", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "t", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})})}),
+        new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "S", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "q", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "u", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})}),
+        new edu.berkeley.sbp.Tree(null, "^", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "&", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "~", new edu.berkeley.sbp.Tree[] { })})}),
+        new edu.berkeley.sbp.Tree(null, "!", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "w", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})}),
+        new edu.berkeley.sbp.Tree(null, "nonTerminal", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "E", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "l", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "m", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "n", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "t", new edu.berkeley.sbp.Tree[] { }),
+        new edu.berkeley.sbp.Tree(null, "s", new edu.berkeley.sbp.Tree[] { })})})})})})})})}),
         new edu.berkeley.sbp.Tree(null, "=", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "e", new edu.berkeley.sbp.Tree[] { }),
         new edu.berkeley.sbp.Tree(null, "c", new edu.berkeley.sbp.Tree[] { })}),
         new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "psx", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "ps", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "~", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "[", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, null, new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "range", new edu.berkeley.sbp.Tree[] { new edu.berkeley.sbp.Tree(null, "-", new edu.berkeley.sbp.Tree[] { })}),
@@ -1125,3 +1120,6 @@ new edu.berkeley.sbp.Tree(null, "gram", new edu.berkeley.sbp.Tree[] { new edu.be
 
 
 
+
+
+
diff --git a/tests/meta.g b/tests/meta.g
index e81e67c..cc33104 100644
--- a/tests/meta.g
+++ b/tests/meta.g
@@ -1,19 +1,19 @@
-s             =  gram::    !ws Grammar ws
+s             =  ws gram:Grammar ws
 Grammar       =  grammar:: NonTerminal +/ ws
 NonTerminal   =            word  !wp ^"=" !wp RHS
         
-RHS           =  (Conjuncts +/ (!ws "|" !ws)) +/ (!ws ">" !ws)
+RHS           =  (Sequence +/ (!ws "|" !ws)) +/ (!ws ">" !ws)
 
-Conjuncts     =  Sequence
-              |  Sequence ^"&"  Elements  /ws
-              |  Sequence ^"&~" Elements  /ws
 Elements      =  e*/ws
 
 PreSequence   = ps::  Elements
               |       PreSequence !wp ^"/"  !ws e
               |       PreSequence     ^"->"     e /ws
               |       (Quoted|word)   ^"::" PreSequence /ws
+
 Sequence      = psx:: PreSequence
+              |       Sequence !ws ^"&"  !ws Elements
+              |       Sequence !ws ^"&~" !ws Elements
 
 ec            = ~[\-\]\\]
               | escaped
-- 
1.7.10.4