From 98ae7592861f7e7d3bf5744b5db84ffdefc6011d Mon Sep 17 00:00:00 2001
From: adam <adam@megacz.com>
Date: Wed, 28 Jun 2006 18:06:21 -0400
Subject: [PATCH] checkpoint

darcs-hash:20060628220621-5007d-27e1a175e71388d653724107e519e96753fe3b6c.gz
---
 Makefile                                   |    4 +-
 src/edu/berkeley/sbp/misc/Demo.java        |  321 +++++++++++++++++++++++++++-
 src/edu/berkeley/sbp/misc/MetaGrammar.java |   94 ++++----
 3 files changed, 366 insertions(+), 53 deletions(-)

diff --git a/Makefile b/Makefile
index 8cf95ac..c9da038 100644
--- a/Makefile
+++ b/Makefile
@@ -8,8 +8,8 @@ tibdoc: edu.berkeley.sbp.jar
 
 demo: edu.berkeley.sbp.jar
 	$(java) -cp $< edu.berkeley.sbp.misc.Demo \
-		tests/demo.g \
-		tests/demo.in
+		tests/meta.g \
+		tests/meta.g
 
 regress:
 	make boot
diff --git a/src/edu/berkeley/sbp/misc/Demo.java b/src/edu/berkeley/sbp/misc/Demo.java
index 4e0dc1b..02482fa 100644
--- a/src/edu/berkeley/sbp/misc/Demo.java
+++ b/src/edu/berkeley/sbp/misc/Demo.java
@@ -3,19 +3,320 @@ import edu.berkeley.sbp.util.*;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.chr.*;
 import java.util.*;
+import java.lang.annotation.*;
+import java.lang.reflect.*;
 import java.io.*;
 
 public class Demo {
     public static void main(String[] s) throws Exception {
-        /*
-        Tree<String> gram = new CharParser(MetaGrammar.make()).parse(new FileInputStream(s[0])).expand1();
-        MetaGrammar g = (MetaGrammar)new MetaGrammar().walk(gram);
-        Union meta = g.done();
-        //Tree<String> out = new CharParser(meta).parse(new FileInputStream(s[1])).expand1();
-        Forest<String> out = new CharParser(meta).parse(new FileInputStream(s[1]));
-        GraphViz gv = new GraphViz();
-        out.toGraphViz(gv);
-        gv.dump(new PrintWriter(new OutputStreamWriter(System.out)));
-        */
+        Tree<String> res = new CharParser(MetaGrammar.make()).parse(new FileInputStream(s[0])).expand1();
+        
+        MetaGrammar.Meta m =
+            new ReflectiveMeta(MG.class,
+                               new Class[] {
+                                   MG.Grammar.class,
+                                   MG.NonTerminal.class,
+                                   MG.Range.class,
+                                   MG.El.class,
+                                   MG.Seq.class,
+                                   MG.NonTerminalReference.class,
+                                   MG.StringLiteral.class,
+                                   MG.Epsilon.class,
+                                   MG.Tree.class,
+                                   MG.CharClass.class
+                               });
+        MetaGrammar.Meta.MetaGrammarFile mgf = m.new MetaGrammarFile(res);
+        MetaGrammar.BuildContext bc = new MetaGrammar.BuildContext(mgf);
+        Union meta = mgf.get("s").build(bc);
+
+        System.err.println("parsing " + s[1]);
+        res = new CharParser(meta).parse(new FileInputStream(s[1])).expand1();
+
+        System.out.println(res);
+    }
+
+    public static class ReflectiveMeta extends MetaGrammar.Meta {
+        private final Class _cl;
+        private final Class[] _inner;
+        public ReflectiveMeta(Class c, Class[] inner) {
+            this._cl = c;
+            this._inner = inner;
+        }
+        private boolean match(Method m, String s) { return match(m.getAnnotation(tag.class), null, s); }
+        private boolean match(tag t, Class c, String s) {
+            if (t==null) return false;
+            if (t.value().equals(s)) return true;
+            if (c != null && t.equals("") && c.getSimpleName().equals(s)) return true;
+            return false;
+        }
+        private boolean match(nonterminal t, Class c, String s) {
+            if (t==null) return false;
+            if (t.value().equals(s)) return true;
+            if (c != null && t.equals("") && c.getSimpleName().equals(s)) return true;
+            return false;
+        }
+        private boolean match(Class c, String s, String nonTerminalName) {
+            if (match((tag)c.getAnnotation(tag.class), c, s)) return true;
+            if (match((nonterminal)c.getAnnotation(nonterminal.class), c, nonTerminalName)) return true;
+            return false;
+        }
+        public boolean match(Constructor con, String s, String nonTerminalName) {
+            Class c = con.getDeclaringClass();
+            if (match((tag)con.getAnnotation(tag.class), null, s)) return true;
+            if (match((nonterminal)con.getAnnotation(nonterminal.class), c, s)) return true;
+            return false;
+        }
+        public Sequence resolveTag(String tag, String nonTerminalName, Element[] els, Object[] labels, boolean[] drops) {
+            Production p = new Production(tag, nonTerminalName, els, labels, drops);
+            for(Method m : _cl.getMethods())
+                if (new TargetMethod(m).isCompatible(p))
+                    return Sequence.rewritingSequence(m, els, labels, drops);
+            for(Class c : _inner)
+                for(Constructor con : c.getConstructors())
+                    if (new TargetConstructor(con).isCompatible(p))
+                        return Sequence.rewritingSequence(con, els, labels, drops);
+            for(Class c : _inner)
+                if (new TargetClass(c).isCompatible(p))
+                    return Sequence.rewritingSequence(c, els, labels, drops);
+            throw new RuntimeException("could not find a Java method/class/ctor matching tag \""+tag+"\", nonterminal \""+nonTerminalName+"\"");
+        }
     }
+    /*
+    public static Object makeFlattener(final Method m, final Element[] els, final Object[] labels, final boolean[] drops) {
+        return new Reducer() {
+                public Object reduce(Tree t) {
+                    Object[] o = new Object[m.getParameterTypes()];
+                    int j = 0;
+                    for(int i=0; i<els.length; i++)
+                }
+            };
+    }
+    */
+
+    
+    /**
+     *  Constructors, classes, and methods with this attribute will
+     *  match every production of the nonterminal called "value()"
+     *  that is arg-compatible.  If value() is undefined, then the
+     *  class/constructor/method name is used.
+     */ 
+    @Retention(RetentionPolicy.RUNTIME) public static @interface nonterminal { String value() default ""; }
+
+    /**
+     *  Constructors, classes, and methods with this attribute will
+     *  match every tree tagged with "value()" that is arg-compatible.
+     *  If value() is undefined, then the class/constructor/method
+     *  name is used.
+     */ 
+    @Retention(RetentionPolicy.RUNTIME) public static @interface tag         { String value() default ""; }
+
+    /**
+     *  If any parameter to a method or field in a class has a named
+     *  arg-tag, that parameter/field matches the child of the tree
+     *  which either has that label or else is a reference to a
+     *  nonterminal with the corresponding name.
+     *  
+     *  The remaining non-named arg-tags match the remaining children
+     *  of the tree in sequential order.
+     *
+     *  If any arg-tagged parameters/fields remain, the match fails.
+     *  If there were no arg-tagged parameters-fields, it is as if all
+     *  of them were non-named and arg-tagged.
+     *
+     *  A method/constructor is arg-compatible if all of its arguments
+     *  are arg-compatible.
+     *
+     *  A class is arg-compatible if all of its fields are
+     *  arg-compatible, or if one of its constructors is arg-compatible.
+     *
+     */
+    @Retention(RetentionPolicy.RUNTIME) public static @interface arg         { String value() default ""; }
+
+    public static class Production {
+        public String tag;
+        public String nonTerminal;
+        public Object[] labels;
+        public boolean[] drops;
+        public Element[] elements;
+        public int count = 0;
+        public Production(String tag, String nonTerminal, Element[] elements, Object[] labels, boolean[] drops) {
+            this.tag = tag;
+            this.elements = elements; // FIXME: use this
+            this.nonTerminal = nonTerminal;
+            this.labels = labels;
+            this.drops = drops;
+            for(int i=0; i<drops.length; i++)
+                if (!drops[i])
+                    count++;
+        }
+    }
+
+    public static abstract class Target {
+        public abstract String getName();
+        public abstract tag getTag();
+        public abstract nonterminal getNonTerminal();
+        public abstract boolean buildSequence(Production p);
+        public boolean isCompatible(Production p) {
+            tag t = getTag();
+            if (t != null &&
+                (t.value().equals(p.tag) ||
+                 (t.value().equals("") && p.tag.equals(getName()))))
+                return buildSequence(p);
+
+            nonterminal n = getNonTerminal();
+            if (n != null &&
+                (n.value().equals(p.nonTerminal) ||
+                 (n.value().equals("") && p.nonTerminal.equals(getName()))))
+                return buildSequence(p);
+
+            return false;
+        }
+        public int[] buildSequence(Production p, String[] names, arg[] argtags) {
+            int argTagged = 0;
+            for(int i=0; i<argtags.length; i++)
+                if (argtags[i] != null)
+                    argTagged++;
+
+            // FIXME: can be smarter here
+            if (names.length==p.count) {
+                int[] ret = new int[p.count];
+                for(int i=0; i<p.count; i++) ret[i] = i;
+                return ret;
+            } else if (argTagged==p.count) {
+                int[] ret = new int[argTagged];
+                int j = 0;
+                for(int i=0; i<argtags.length; i++)
+                    if (argtags[i]!=null)
+                        ret[j++] = i;
+                return ret;
+            } else {
+                return null;
+            }
+        }
+    }
+    public static class TargetClass extends Target {
+        public final Class _class;
+        public TargetClass(Class _class) { this._class = _class; }
+        public String getName() { return _class.getSimpleName(); }
+        public tag getTag() { return (tag)_class.getAnnotation(tag.class); }
+        public nonterminal getNonTerminal() { return (nonterminal)_class.getAnnotation(nonterminal.class); }
+        public boolean buildSequence(Production p) {
+            Field[]  f       = _class.getDeclaredFields();
+            String[] names   = new String[f.length];
+            arg[]    argtags = new arg[f.length];
+            for(int i=0; i<f.length; i++) {
+                names[i]   = f[i].getName();
+                argtags[i] = f[i].getAnnotation(arg.class);
+            }
+            int[] ret = buildSequence(p, names, argtags);
+            if (ret!=null) return true;
+            for(Constructor c : _class.getConstructors())
+                if (new TargetConstructor(c).buildSequence(p))
+                    return true;
+            return false;
+        }
+    }
+    public static class TargetConstructor extends Target {
+        public final Constructor _ctor;
+        public TargetConstructor(Constructor _ctor) { this._ctor = _ctor; }
+        public String getName() { return _ctor.getName(); }
+        public tag getTag() { return (tag)_ctor.getAnnotation(tag.class); }
+        public nonterminal getNonTerminal() { return (nonterminal)_ctor.getAnnotation(nonterminal.class); }
+        public boolean buildSequence(Production p) {
+            Annotation[][] annotations = _ctor.getParameterAnnotations();
+            int len = annotations.length;
+            int ofs = 0;
+            String name = _ctor.getDeclaringClass().getName();
+            if (name.indexOf('$') > name.lastIndexOf('.')) {
+                len--;
+                ofs++;
+            }
+            String[] names   = new String[len];
+            arg[]    argtags = new arg[len];
+            for(int i=0; i<names.length; i++)
+                for(Annotation a : annotations[i+ofs])
+                    if (a instanceof arg)
+                        argtags[i+ofs] = (arg)a;
+            int[] ret = buildSequence(p, names, argtags);
+            if (ret!=null) return true;
+            return false;
+        }
+    }
+    public static class TargetMethod extends Target {
+        public final Method _method;
+        public TargetMethod(Method _method) { this._method = _method; }
+        public String getName() { return _method.getName(); }
+        public tag getTag() { return (tag)_method.getAnnotation(tag.class); }
+        public nonterminal getNonTerminal() { return (nonterminal)_method.getAnnotation(nonterminal.class); }
+        public boolean buildSequence(Production p) {
+            Annotation[][] annotations = _method.getParameterAnnotations();
+            String[] names   = new String[annotations.length];
+            arg[]    argtags = new arg[annotations.length];
+            for(int i=0; i<names.length; i++)
+                for(Annotation a : annotations[i])
+                    if (a instanceof arg)
+                        argtags[i] = (arg)a;
+            int[] ret = buildSequence(p, names, argtags);
+            if (ret!=null) return true;
+            return false;
+        }
+    }
+
+    public class MG {
+        public @tag void grammar(Grammar g) { }
+        public @nonterminal void Grammar(NonTerminal[] n) { }
+        public @nonterminal class Grammar {
+            public @arg("NonTerminal") NonTerminal[] nonterminals;
+        }
+        public @nonterminal class NonTerminal {
+            public @arg("Word") String  name;
+            public @arg("RHS")  Seq[][] sequences;
+        }
+
+        public @tag void range(char c) { }
+        public @nonterminal class Range {
+            public @tag("range") Range(char only) { first = only; last = only; }
+            public @arg char first;
+            public @arg char last;
+        }
+        public class El { }
+        public abstract @nonterminal("Sequence") class Seq { }
+        public @tag("&")   Seq and(Sequence s,    Element[] elements) { return null; }
+        public @tag("&~")  Seq andnot(Sequence s, Element[] elements) { return null; }
+        public @tag        Seq ps(Element[] elements) { return null; }
+        public @tag("::")  Seq tag(String tagname, Seq seq) { return null; }
+        public @tag(":")   void colon(String s, Element e) { }
+        public @tag(")")   void close(String foo) { }
+        public @tag("/")   Seq slash(Seq s, Element e) { return null; }
+        public @tag("->")  Seq arrow(Seq s, Element e) { return null; }
+
+        public @tag("nonTerminal") class NonTerminalReference { public @arg String nonTerminal; }
+        public @tag("literal")     class StringLiteral        { public @arg String string; }
+        public @tag("()")          class Epsilon              { }
+        public @tag("{")           class Tree                 { @arg Seq body; }
+        public @tag("[")           class CharClass            { public CharClass(Range[] ranges) { } }
+
+        public @tag("++")  void plusmax(El e) { }
+        public @tag("+")   void plus(El e) { }
+        public @tag("++/") void plusmaxfollow(El e, El sep) { }
+        public @tag("+/")  void plusfollow(El e, El sep) { }
+        public @tag("**")  void starmax(El e) { }
+        public @tag("*")   void star(El e) { }
+        public @tag("**/") void starmaxfollow(El e, El sep) { }
+        public @tag("*/")  void starfollow(El e, El sep) { }
+        public @tag("!")   void bang(El e) { }
+        public @tag("?")   void question(El e) { }
+        public @tag("^")   void caret(String s) { }
+        public @tag("~")   void tilde(El e) { }
+        public @tag("^^")  void doublecaret(El e) { }
+        public @tag("(")   void subexpression(Seq[][] rhs) { }
+
+        public @nonterminal("Word")    String word(String s) { return null; }
+        public @nonterminal("Quoted")  String quoted(String s) { return null; }
+        public @nonterminal("escaped") String c(char c) { return null; }
+        public @tag("\"\"")            String emptystring() { return null; }
+        public @tag("\r")              String lf() { return null; }
+        public @tag("\n")              String cr() { return null; }
+    }
+
 }
diff --git a/src/edu/berkeley/sbp/misc/MetaGrammar.java b/src/edu/berkeley/sbp/misc/MetaGrammar.java
index f5fff5d..3420ad5 100644
--- a/src/edu/berkeley/sbp/misc/MetaGrammar.java
+++ b/src/edu/berkeley/sbp/misc/MetaGrammar.java
@@ -39,42 +39,54 @@ public class MetaGrammar extends StringWalker {
 
     public static class BuildContext extends HashMap<String,Union> {
         private final Meta.MetaGrammarFile mgf;
+        public Meta.NonTerminal currentNonTerminal;
         public BuildContext(Meta.MetaGrammarFile mgf) { this.mgf = mgf; }
         public Union build(String s) {
             Union ret = get(s);
             if (ret != null) return ret;
-            Meta.MetaNonterminal mnt = mgf.get(s);
+            Meta.NonTerminal mnt = mgf.get(s);
             if (mnt==null) throw new Error("undeclared nonterminal \""+s+"\"");
             return mnt.build(this);
         }
     }
 
     public static class Meta {
-        public class MetaGrammarFile extends HashMap<String,MetaNonterminal> {
+        public Sequence resolveTag(String s, String nonTerminalName, Element[] els, Object[] labels, boolean [] drops) {
+            return Sequence.rewritingSequence(s, els, labels, drops);
+        }
+        public class MetaGrammarFile extends HashMap<String,NonTerminal> {
             public MetaGrammarFile(Tree<String> tree) {
                 if (!tree.head().equals("grammar")) throw new Error();
                 for(Tree<String> nt : tree.child(0))
-                    add(new MetaNonterminal(nt));
+                    add(new NonTerminal(nt));
             }
-            private void add(MetaNonterminal mnt) {
+            private void add(NonTerminal mnt) {
                 if (this.get(mnt.name)!=null) throw new Error("duplicate definition of nonterminal \""+mnt.name+"\"");
                 this.put(mnt.name, mnt);
             }
             public String toString() {
                 String ret = "";
-                for(MetaNonterminal mnt : this.values()) ret += mnt + "\n";
+                for(NonTerminal mnt : this.values()) ret += mnt + "\n";
                 return ret;
             }
         }
-        public class MetaNonterminal {
+        public class NonTerminal {
             public String    name;
             public MetaUnion rhs;
-            public MetaNonterminal(Tree<String> tree) {
+            public NonTerminal(Tree<String> tree) {
                 name = string(tree.child(0));
                 rhs = rhs(tree.child(1));
             }
             public String toString() { return name + " = " + rhs; }
-            public Union build(BuildContext bc) { return rhs.build(bc, name); }
+            public Union build(BuildContext bc) {
+                NonTerminal ont = bc.currentNonTerminal;
+                bc.currentNonTerminal = this;
+                try {
+                    return rhs.build(bc, name);
+                } finally {
+                    bc.currentNonTerminal = ont;
+                }
+            }
         }
         public MetaUnion rhs(Tree<String> t) {
             return t.numChildren()==1
@@ -137,9 +149,9 @@ public class MetaGrammar extends StringWalker {
         }
 
         public MetaSequence makeMetaSequence(Tree<String> t) {
-            if ("psx".equals(t.head())) return makeMetaConjunct(t.child(0));
-            if (t.head().equals("&"))  return new MetaAnd(makeMetaSequence(t.child(0)), makeMetaConjunct(t.child(1)), false);
-            if (t.head().equals("&~")) return new MetaAnd(makeMetaSequence(t.child(0)), makeMetaConjunct(t.child(1)), true);
+            if ("psx".equals(t.head())) return makeConjunct(t.child(0));
+            if (t.head().equals("&"))  return new MetaAnd(makeMetaSequence(t.child(0)), makeConjunct(t.child(1)), false);
+            if (t.head().equals("&~")) return new MetaAnd(makeMetaSequence(t.child(0)), makeConjunct(t.child(1)), true);
             return null;
         }
 
@@ -166,7 +178,7 @@ public class MetaGrammar extends StringWalker {
             public String toString() { return left + " &"+(not?"~":"")+" "+right; }
         }
 
-        public class MetaConjunct implements MetaSequence {
+        public class Conjunct implements MetaSequence {
             public boolean negated = false;
             public MetaClause[] elements;
             public HashMap<MetaClause,String> labelMap = new HashMap<MetaClause,String>();
@@ -198,7 +210,7 @@ public class MetaGrammar extends StringWalker {
                 if (dropAll)     ret = Sequence.drop(els, false);
                 else if (unwrap) ret = Sequence.unwrap(els, /*repeatTag FIXME*/null, drops);
                 else if (tag!=null) {
-                    ret = Sequence.rewritingSequence(tag, els, labels, drops);
+                    ret = resolveTag(tag, bc.currentNonTerminal==null ? null : bc.currentNonTerminal.name, els, labels, drops);
                 } else {
                     int idx = -1;
                     for(int i=0; i<els.length; i++)
@@ -212,7 +224,7 @@ public class MetaGrammar extends StringWalker {
                     ret.follow = infer(this.followedBy.build(bc));
                 return ret;
             }
-            private MetaConjunct(Tree<String> t) {
+            private Conjunct(Tree<String> t) {
                 elements = new MetaClause[t.numChildren()];
                 int i = 0; for(Tree<String> tt : t)
                     elements[i++] = makeMetaClause(tt, this);
@@ -227,33 +239,33 @@ public class MetaGrammar extends StringWalker {
                 return ret;
             }
         }
-            public MetaConjunct makeMetaConjunct(Tree<String> t) {
-                //System.err.println("makeMetaConjunct("+t+")");
+            public Conjunct makeConjunct(Tree<String> t) {
+                //System.err.println("makeConjunct("+t+")");
                 if ("/".equals(t.head())) {
-                    MetaConjunct ret = makeMetaConjunct(t.child(0));
+                    Conjunct ret = makeConjunct(t.child(0));
                     ret.separator = makeMetaClause(t.child(1), ret);
                     return ret;
                 }
                 if ("->".equals(t.head())) {
-                    MetaConjunct ret = makeMetaConjunct(t.child(0));
+                    Conjunct ret = makeConjunct(t.child(0));
                     ret.followedBy = makeMetaClause(t.child(1), ret);
                     return ret;
                 }
                 if ("::".equals(t.head())) {
-                    MetaConjunct ret = makeMetaConjunct(t.child(1));
+                    Conjunct ret = makeConjunct(t.child(1));
                     ret.tag = string(t.child(0));
                     return ret;
                 }
                 if ("ps".equals(t.head())) {
-                    return new MetaConjunct(t.child(0));
+                    return new Conjunct(t.child(0));
                 }
-                return new MetaConjunct(t);
+                return new Conjunct(t);
             }
 
-            public MetaClause makeMetaClause(Tree<String> t, MetaConjunct c) {
+            public MetaClause makeMetaClause(Tree<String> t, Conjunct c) {
                 //System.err.println("MetaClause.makeMetaClause("+t+")");
-                if (t==null) return new MetaEpsilon();
-                if (t.head()==null) return new MetaEpsilon();
+                if (t==null) return new Epsilon();
+                if (t.head()==null) return new Epsilon();
                 if (t.head().equals("{")) throw new Error("metatree: " + t);
                 if (t.head().equals("*")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, null, true, true);
                 if (t.head().equals("+")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, null, false, true);
@@ -264,15 +276,15 @@ public class MetaGrammar extends StringWalker {
                 if (t.head().equals("+/")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, makeMetaClause(t.child(1), c), false, true);
                 if (t.head().equals("**/")) return new MetaRepeat(makeMetaClause(t.child(0), c), true, makeMetaClause(t.child(1), c), true, true);
                 if (t.head().equals("++/")) return new MetaRepeat(makeMetaClause(t.child(0), c), true, makeMetaClause(t.child(1), c), false, true);
-                if (t.head().equals("()")) return new MetaEpsilon();
+                if (t.head().equals("()")) return new Epsilon();
                 if (t.head().equals("[")) return new MetaRange(t.child(0));
-                if (t.head().equals("literal")) return new MetaStringLiteral(t.child(0));
-                if (t.head().equals("nonTerminal")) return new MetaNonterminalReference(t.child(0));
-                if (t.head().equals(")")) return new MetaSelfReference();
-                if (t.head().equals("(")) return new MetaParens(t.child(0));
+                if (t.head().equals("literal")) return new StringLiteral(t.child(0));
+                if (t.head().equals("nonTerminal")) return new NonTerminalReference(t.child(0));
+                if (t.head().equals(")")) return new SelfReference();
+                if (t.head().equals("(")) return new Parens(t.child(0));
                 if (t.head().equals("~")) return new MetaInvert(t.child(0), c);
                 if (t.head().equals("!")) { MetaClause mc = makeMetaClause(t.child(0), c); mc.drop = true; return mc; }
-                if (t.head().equals("^")) { c.tag = string(t.child(0)); return new MetaStringLiteral(t.child(0)); }
+                if (t.head().equals("^")) { c.tag = string(t.child(0)); return new StringLiteral(t.child(0)); }
                 if (t.head().equals("^^")) throw new Error("carets: " + t);
                 if (t.head().equals(":")) {
                     String name = string(t.child(0));
@@ -315,20 +327,20 @@ public class MetaGrammar extends StringWalker {
                         (separator==null?"":(" /"+separator));
                 }
             }
-        public class MetaEpsilon extends MetaClause {
+        public class Epsilon extends MetaClause {
             public String toString() { return "()"; }
             public Element build(BuildContext bc) { return Union.epsilon; }
         }
-            public class MetaParens extends MetaClause {
+            public class Parens extends MetaClause {
                 public MetaUnion body;
-                public MetaParens(Tree<String> t) { this.body = rhs(t); }
+                public Parens(Tree<String> t) { this.body = rhs(t); }
                 public String toString() { return "( " + body + " )"; }
                 public Element build(BuildContext bc) { return body.buildAnon(bc); }
             }
             /*
             public static class MetaTree extends MetaClause {
-                public MetaConjunct body;
-                public MetaTree(Tree<String> t) { this.body = makeMetaConjunct(t); }
+                public Conjunct body;
+                public MetaTree(Tree<String> t) { this.body = makeConjunct(t); }
                 public String toString() { return "{ " + body + " }"; }
                 public Element build(BuildContext bc) {
                     return new Union("{}");// body.buildSequence();
@@ -350,25 +362,25 @@ public class MetaGrammar extends StringWalker {
                     }
                 }
             }
-            public class MetaStringLiteral extends MetaClause {
+            public class StringLiteral extends MetaClause {
                 public String literal;
                 public Element build(BuildContext bc) { return string(literal); }
-                public MetaStringLiteral(Tree<String> literal) { this.literal = string(literal); this.drop = true; }
+                public StringLiteral(Tree<String> literal) { this.literal = string(literal); this.drop = true; }
                 public String toString() { return "\""+StringUtil.escapify(literal, "\"\r\n\\")+"\""; }
             }
-            public class MetaNonterminalReference extends MetaClause {
+            public class NonTerminalReference extends MetaClause {
                 public String name;
-                public MetaNonterminalReference(Tree<String> name) { this.name = string(name); }
+                public NonTerminalReference(Tree<String> name) { this.name = string(name); }
                 public Element build(BuildContext bc) { return bc.build(name); }
                 public String toString() { return name; } 
             }
-            public class MetaSelfReference extends MetaClause {
+            public class SelfReference extends MetaClause {
                 public String toString() { return "(*)"; } 
                 public Element build(BuildContext bc) { return new Union("(*)"); /* FIXME */ }
             }
             public class MetaInvert extends MetaClause {
                 public MetaClause element;
-                public MetaInvert(Tree<String> t, MetaConjunct c) { this.element = makeMetaClause(t, c); }
+                public MetaInvert(Tree<String> t, Conjunct c) { this.element = makeMetaClause(t, c); }
                 public String toString() { return "~"+element; }
                 public Element build(BuildContext bc) { return infer((Topology<Character>)Atom.toAtom(element.build(bc)).complement()); }
             }
-- 
1.7.10.4