src/edu/berkeley/sbp/misc/MetaGrammar.java

   1 package edu.berkeley.sbp.misc;
   2 import edu.berkeley.sbp.util.*;
   3 import edu.berkeley.sbp.*;
   4 import edu.berkeley.sbp.chr.*;
   5 import java.util.*;
   6 import java.io.*;
   7
   8 public class MetaGrammar extends StringWalker {
   9
  10     public static Union make() throws Exception { return make(MetaGrammarTree.meta, "s"); }
  11     public static Union make(Tree<String> tree, String nt) throws Exception {
  12         Meta.MetaGrammarFile mgf = new Meta().new MetaGrammarFile(tree);
  13         BuildContext bc = new BuildContext(mgf);
  14         return mgf.get(nt).build(bc);
  15     }
  16
  17     ////////////////////////////////////////////////////////////////////////////////
  18
  19     private static Element  set(Range.Set r) { return CharRange.set(r); }
  20     private static Element  string(String s) { return CharRange.string(s); }
  21     /*private*/ static Atom infer(Element e)  { return infer((Topology<Character>)Atom.toAtom(e)); }
  22     /*private*/ static Atom infer(Topology<Character> t) { return new CharRange(new CharTopology(t)); }
  23
  24     private MetaGrammar() { }
  25
  26     public static String string(Iterable<Tree<String>> children) {
  27         String ret = "";
  28         for(Tree<String> t : children) ret += string(t);
  29         return ret;
  30     }
  31     public static String string(Tree<String> tree) {
  32         String ret = "";
  33         if (tree.head()!=null) ret += tree.head();
  34         ret += string(tree.children());
  35         return ret;
  36     }
  37
  38     public static class BuildContext extends HashMap<String,Union> {
  39         private final Meta.MetaGrammarFile mgf;
  40         public Meta.NonTerminal currentNonTerminal;
  41         public BuildContext(Meta.MetaGrammarFile mgf) { this.mgf = mgf; }
  42         public Union build(String s) {
  43             Union ret = get(s);
  44             if (ret != null) return ret;
  45             Meta.NonTerminal mnt = mgf.get(s);
  46             if (mnt==null) throw new Error("undeclared nonterminal \""+s+"\"");
  47             return mnt.build(this);
  48         }
  49     }
  50
  51     public static class Meta {
  52         public Object repeatTag() { return null; }
  53         public Sequence tryResolveTag(String s, String nonTerminalName, Element[] els, Object[] labels, boolean [] drops) {
  54             //return resolveTag(s, nonTerminalName, els, labels, drops);
  55             return null;
  56         }
  57         public Sequence resolveTag(String s, String nonTerminalName, Element[] els, Object[] labels, boolean [] drops) {
  58             return Sequence.rewritingSequence(s, els, labels, drops);
  59         }
  60         public class MetaGrammarFile extends HashMap<String,NonTerminal> {
  61             public MetaGrammarFile(Tree<String> tree) {
  62                 if (!tree.head().equals("grammar")) throw new Error();
  63                 for(Tree<String> nt : tree.child(0))
  64                     add(new NonTerminal(nt));
  65             }
  66             private void add(NonTerminal mnt) {
  67                 if (this.get(mnt.name)!=null) throw new Error("duplicate definition of nonterminal \""+mnt.name+"\"");
  68                 this.put(mnt.name, mnt);
  69             }
  70             public String toString() {
  71                 String ret = "";
  72                 for(NonTerminal mnt : this.values()) ret += mnt + "\n";
  73                 return ret;
  74             }
  75         }
  76         public class NonTerminal {
  77             public String    name;
  78             public MetaUnion rhs;
  79             public NonTerminal(Tree<String> tree) {
  80                 name = string(tree.child(0));
  81                 rhs = rhs(tree.child(1));
  82             }
  83             public String toString() { return name + " = " + rhs; }
  84             public Union build(BuildContext bc) {
  85                 NonTerminal ont = bc.currentNonTerminal;
  86                 bc.currentNonTerminal = this;
  87                 try {
  88                     return rhs.build(bc, name);
  89                 } finally {
  90                     bc.currentNonTerminal = ont;
  91                 }
  92             }
  93         }
  94         public MetaUnion rhs(Tree<String> t) {
  95             return t.numChildren()==1
  96                 ? new MetaUnion(t.child(0), false)
  97                 : new MetaUnion(t, true);
  98         }
  99         public class MetaUnion implements MetaSequence {
 100             public boolean prioritized;
 101             public MetaSequence[] sequences;
 102             public Sequence buildSequence(BuildContext bc) {
 103                 return Sequence.singleton(new Element[] { buildAnon(bc) }, 0);
 104             }
 105             public Union buildAnon(BuildContext bc) {
 106                 String s = "";
 107                 for(int i=0; i<sequences.length; i++)
 108                     s += (i>0?"\n                "+(prioritized?">":"|")+" ":"")+sequences[i].buildSequence(bc);
 109                 return build(bc, s);
 110             }
 111             public Union build(BuildContext bc, String name) {
 112                 Union u = bc.get(name);
 113                 if (u != null) return u;
 114                 u = new Union(name);
 115                 bc.put(name, u);
 116                 HashSet<Sequence> seqs = new HashSet<Sequence>();
 117                 for(MetaSequence s : sequences) {
 118                     Sequence seq = s.buildSequence(bc);
 119                     if (seq != null) {
 120                         Sequence oseq = seq;
 121                         if (prioritized)
 122                             for(Sequence seqprev : seqs)
 123                                 seq = seq.not(seqprev);
 124                         u.add(seq);
 125                         seqs.add(seq);
 126                     }
 127                 }
 128                 return u;
 129             }
 130             public MetaUnion(Tree<String> t, boolean prioritized) {
 131                 this.prioritized = prioritized;
 132                 int i = 0;
 133                 this.sequences = new MetaSequence[t.numChildren()];
 134                 for(Tree<String> tt : t)
 135                     sequences[i++] = prioritized
 136                         ? new MetaUnion(tt, false)
 137                         : makeMetaSequence(tt);
 138             }
 139             public String toString() {
 140                 String ret = "\n     ";
 141                 for(int i=0; i<sequences.length; i++) {
 142                     ret += sequences[i];
 143                     if (i<sequences.length-1)
 144                         ret += (prioritized ? "\n    > " : "\n    | ");
 145                 }
 146                 return ret;
 147             }
 148         }
 149
 150         public interface MetaSequence {
 151             public abstract Sequence buildSequence(BuildContext bc);
 152         }
 153
 154         public MetaSequence makeMetaSequence(Tree<String> t) {
 155             if ("psx".equals(t.head())) return makeConjunct(t.child(0));
 156             if (t.head().equals("&"))  return new MetaAnd(makeMetaSequence(t.child(0)), makeConjunct(t.child(1)), false);
 157             if (t.head().equals("&~")) return new MetaAnd(makeMetaSequence(t.child(0)), makeConjunct(t.child(1)), true);
 158             return null;
 159         }
 160
 161         public class MetaAnd implements MetaSequence {
 162             boolean not;
 163             MetaSequence left;
 164             MetaSequence right;
 165             public Sequence buildSequence(BuildContext bc) {
 166                 Union u = new Union(toString());
 167                 Sequence ret = left.buildSequence(bc);
 168                 Sequence rs = right.buildSequence(bc);
 169                 rs.lame = true;
 170                 if (not) ret = ret.not(rs);
 171                 else     ret = ret.and(rs);
 172                 u.add(rs);
 173                 u.add(ret);
 174                 return Sequence.singleton(u);
 175             }
 176             public MetaAnd(MetaSequence left, MetaSequence right, boolean not) {
 177                 this.left = left;
 178                 this.right = right;
 179                 this.not = not;
 180             }
 181             public String toString() { return left + " &"+(not?"~":"")+" "+right; }
 182         }
 183
 184         public class Conjunct implements MetaSequence {
 185             public boolean negated = false;
 186             public MetaClause[] elements;
 187             public HashMap<MetaClause,String> labelMap = new HashMap<MetaClause,String>();
 188             public MetaClause followedBy = null;
 189             public String tag;
 190             public MetaClause separator;
 191             public void addNamedClause(String name, MetaClause mc) {
 192                 labelMap.put(mc, name);
 193             }
 194             public Sequence buildSequence(BuildContext bc) {
 195                 Element[] els = new Element[elements.length + (separator==null?0:(elements.length-1))];
 196                 boolean[] drops = new boolean[elements.length + (separator==null?0:(elements.length-1))];
 197                 Object[] labels = new Object[els.length];
 198                 boolean unwrap = false;
 199                 boolean dropAll = false;
 200                 if (tag!=null && tag.equals("[]")) unwrap = true;
 201                 if (tag!=null && "()".equals(tag)) dropAll=true;
 202
 203                 NonTerminal old = bc.currentNonTerminal;
 204                 bc.currentNonTerminal = null;
 205                 for(int i=0; i<elements.length; i++) {
 206                     int j = separator==null ? i : i*2;
 207                     els[j] = elements[i].build(bc);
 208                     labels[j] = labelMap.get(elements[i]);
 209                     drops[j] = elements[i].drop;
 210                     if (separator!=null && i<elements.length-1) {
 211                         els[j+1] = separator.build(bc);
 212                         drops[j+1] = true;
 213                     }
 214                 }
 215                 bc.currentNonTerminal = old;
 216
 217                 Sequence ret = null;
 218                 if (dropAll)     ret = Sequence.drop(els, false);
 219                 else if (unwrap) ret = Sequence.unwrap(els, repeatTag(), drops);
 220                 else if (tag!=null) {
 221                     ret = resolveTag(tag, bc.currentNonTerminal==null ? null : bc.currentNonTerminal.name, els, labels, drops);
 222                     System.err.println("resolvetag " + tag + " => " + ret);
 223                 } else {
 224                     ret = tryResolveTag(tag, bc.currentNonTerminal==null ? null : bc.currentNonTerminal.name, els, labels, drops);
 225                     if (ret==null) {
 226                         int idx = -1;
 227                         for(int i=0; i<els.length; i++)
 228                             if (!drops[i])
 229                                 if (idx==-1) idx = i;
 230                                 else throw new Error("multiple non-dropped elements in sequence: " + Sequence.drop(els,false));
 231                         if (idx != -1) ret = Sequence.singleton(els, idx);
 232                         else           ret = Sequence.drop(els, false);
 233                     }
 234                 }
 235                 if (this.followedBy != null)
 236                     ret.follow = infer(this.followedBy.build(bc));
 237                 return ret;
 238             }
 239             private Conjunct(Tree<String> t) {
 240                 elements = new MetaClause[t.numChildren()];
 241                 int i = 0; for(Tree<String> tt : t)
 242                     elements[i++] = makeMetaClause(tt, this);
 243             }
 244             public String toString() {
 245                 String ret = (tag==null ? "" : (tag+":: ")) + (negated ? "~" : "");
 246                 if (elements.length > 1) ret += "(";
 247                 for(MetaClause mc : elements) ret += (" " + mc + " ");
 248                 if (separator != null) ret += " /" + separator;
 249                 if (followedBy != null) ret += " -> " + followedBy;
 250                 if (elements.length > 1) ret += ")";
 251                 return ret;
 252             }
 253         }
 254             public Conjunct makeConjunct(Tree<String> t) {
 255                 //System.err.println("makeConjunct("+t+")");
 256                 if ("/".equals(t.head())) {
 257                     Conjunct ret = makeConjunct(t.child(0));
 258                     ret.separator = makeMetaClause(t.child(1), ret);
 259                     return ret;
 260                 }
 261                 if ("->".equals(t.head())) {
 262                     Conjunct ret = makeConjunct(t.child(0));
 263                     ret.followedBy = makeMetaClause(t.child(1), ret);
 264                     return ret;
 265                 }
 266                 if ("::".equals(t.head())) {
 267                     Conjunct ret = makeConjunct(t.child(1));
 268                     ret.tag = string(t.child(0));
 269                     return ret;
 270                 }
 271                 if ("ps".equals(t.head())) {
 272                     return new Conjunct(t.child(0));
 273                 }
 274                 return new Conjunct(t);
 275             }
 276
 277             public MetaClause makeMetaClause(Tree<String> t, Conjunct c) {
 278                 //System.err.println("MetaClause.makeMetaClause("+t+")");
 279                 if (t==null) return new Epsilon();
 280                 if (t.head()==null) return new Epsilon();
 281                 if (t.head().equals("{")) return new MetaTree(makeConjunct(t.child(0)));
 282                 if (t.head().equals("*")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, null, true, true);
 283                 if (t.head().equals("+")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, null, false, true);
 284                 if (t.head().equals("?")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, null, true, false);
 285                 if (t.head().equals("**")) return new MetaRepeat(makeMetaClause(t.child(0), c), true, null, true, true);
 286                 if (t.head().equals("++")) return new MetaRepeat(makeMetaClause(t.child(0), c), true, null, false, true);
 287                 if (t.head().equals("*/")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, makeMetaClause(t.child(1), c), true, true);
 288                 if (t.head().equals("+/")) return new MetaRepeat(makeMetaClause(t.child(0), c), false, makeMetaClause(t.child(1), c), false, true);
 289                 if (t.head().equals("**/")) return new MetaRepeat(makeMetaClause(t.child(0), c), true, makeMetaClause(t.child(1), c), true, true);
 290                 if (t.head().equals("++/")) return new MetaRepeat(makeMetaClause(t.child(0), c), true, makeMetaClause(t.child(1), c), false, true);
 291                 if (t.head().equals("()")) return new Epsilon();
 292                 if (t.head().equals("[")) return new MetaRange(t.child(0));
 293                 if (t.head().equals("literal")) return new StringLiteral(t.child(0));
 294                 if (t.head().equals("nonTerminal")) return new NonTerminalReference(t.child(0));
 295                 if (t.head().equals(")")) return new SelfReference();
 296                 if (t.head().equals("(")) return new Parens(t.child(0));
 297                 if (t.head().equals("~")) return new MetaInvert(t.child(0), c);
 298                 if (t.head().equals("!")) { MetaClause mc = makeMetaClause(t.child(0), c); mc.drop = true; return mc; }
 299                 if (t.head().equals("^")) { c.tag = string(t.child(0)); return new StringLiteral(t.child(0)); }
 300                 if (t.head().equals("^^")) throw new Error("carets: " + t);
 301                 if (t.head().equals(":")) {
 302                     String name = string(t.child(0));
 303                     MetaClause clause = makeMetaClause(t.child(1), c);
 304                     c.addNamedClause(name, clause);
 305                     return clause;
 306                 }
 307                 throw new Error("unknown: " + t);
 308             }
 309
 310         public abstract class MetaClause {
 311             public String label = null;
 312             public boolean drop = false;
 313             public boolean lift = false;
 314             public abstract Element build(BuildContext bc);
 315         }
 316             public class MetaRepeat extends MetaClause {
 317                 public MetaClause element, separator;
 318                 public boolean maximal, zero, many;
 319                 public Element build(BuildContext bc) {
 320                     return !maximal
 321                         ? (separator==null
 322                            ? Sequence.repeat(element.build(bc), zero, many, null, repeatTag())
 323                            : Sequence.repeat(element.build(bc), zero, many, separator.build(bc), repeatTag()))
 324                         : (separator==null
 325                            ? Sequence.repeatMaximal(infer(element.build(bc)), zero, many, repeatTag())
 326                            : Sequence.repeatMaximal(element.build(bc), zero, many, infer(separator.build(bc)), repeatTag()));
 327                 }
 328                 public MetaRepeat(MetaClause element, boolean maximal, MetaClause separator, boolean zero, boolean many) {
 329                     this.separator = separator;
 330                     this.element = element;
 331                     this.maximal = maximal;
 332                     this.zero = zero;
 333                     this.many = many;
 334                 }
 335                 public String toString() {
 336                     return element+
 337                         ((zero&&!many)?"?":zero?"*":"+")+
 338                         (!maximal?"":zero?"*":"+")+
 339                         (separator==null?"":(" /"+separator));
 340                 }
 341             }
 342         public class Epsilon extends MetaClause {
 343             public String toString() { return "()"; }
 344             public Element build(BuildContext bc) { return Union.epsilon; }
 345         }
 346             public class Parens extends MetaClause {
 347                 public MetaUnion body;
 348                 public Parens(Tree<String> t) { this.body = rhs(t); }
 349                 public String toString() { return "( " + body + " )"; }
 350                 public Element build(BuildContext bc) { return body.buildAnon(bc); }
 351             }
 352
 353             public class MetaTree extends MetaClause {
 354                 public Conjunct body;
 355                 public MetaTree(Conjunct c) { this.body = c; }
 356                 public String toString() { return "{ " + body + " }"; }
 357                 public Element build(BuildContext bc) {
 358                     Union u = new Union();
 359                     Union u2 = new Union();
 360                     Sequence seq = body.buildSequence(bc);
 361                     u2.add(seq);
 362                     u.add(Sequence.singleton(new Element[] { CharRange.leftBrace,
 363                                                              new NonTerminalReference("ws").build(bc),
 364                                                              u2,
 365                                                              new NonTerminalReference("ws").build(bc),
 366                                                              CharRange.rightBrace }
 367                                              , 2));
 368                     //u.add(seq);
 369                     return u;
 370                 }
 371             }
 372
 373             public class MetaRange extends MetaClause {
 374                 Range.Set range = new Range.Set();
 375                 public String toString() { return range.toString(); }
 376                 public Element build(BuildContext bc) { return set(range); }
 377                 public MetaRange(Tree<String> t) {
 378                     for(Tree<String> tt : t) {
 379                         if (tt.head().equals("range")) {
 380                             range.add(tt.child(0).head().charAt(0));
 381                         } else if (tt.head().equals("-")) {
 382                             range.add(new Range(string(tt.child(0)).charAt(0),
 383                                                 string(tt.child(1)).charAt(0)));
 384                         }
 385                     }
 386                 }
 387             }
 388             public class StringLiteral extends MetaClause {
 389                 public String literal;
 390                 public Element build(BuildContext bc) { return string(literal); }
 391                 public StringLiteral(Tree<String> literal) { this.literal = string(literal); this.drop = true; }
 392                 public String toString() { return "\""+StringUtil.escapify(literal, "\"\r\n\\")+"\""; }
 393             }
 394             public class NonTerminalReference extends MetaClause {
 395                 public String name;
 396                 public NonTerminalReference(Tree<String> name) { this.name = string(name); }
 397                 public NonTerminalReference(String name) { this.name = name; }
 398                 public Element build(BuildContext bc) { return bc.build(name); }
 399                 public String toString() { return name; }
 400             }
 401             public class SelfReference extends MetaClause {
 402                 public String toString() { return "(*)"; }
 403                 public Element build(BuildContext bc) { return new Union("(*)"); /* FIXME */ }
 404             }
 405             public class MetaInvert extends MetaClause {
 406                 public MetaClause element;
 407                 public MetaInvert(Tree<String> t, Conjunct c) { this.element = makeMetaClause(t, c); }
 408                 public String toString() { return "~"+element; }
 409                 public Element build(BuildContext bc) { return infer((Topology<Character>)Atom.toAtom(element.build(bc)).complement()); }
 410             }
 411
 412     }
 413
 414     public static void main(String[] args) throws Exception {
 415         if (args.length != 2) {
 416             System.err.println("usage: java " + MetaGrammar.class.getName() + " grammarfile.g com.yourdomain.package.ClassName");
 417             System.exit(-1);
 418         }
 419         //StringBuffer sbs = new StringBuffer();
 420         //((MetaGrammar)new MetaGrammar().walk(meta)).nt.get("e").toString(sbs);
 421         //System.err.println(sbs);
 422         String className   = args[1].substring(args[1].lastIndexOf('.')+1);
 423         String packageName = args[1].substring(0, args[1].lastIndexOf('.'));
 424         String fileName    = packageName.replace('.', '/') + "/" + className + ".java";
 425
 426         BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(fileName)));
 427         StringBuffer out = new StringBuffer();
 428
 429         boolean skip = false;
 430         for(String s = br.readLine(); s != null; s = br.readLine()) {
 431             if (s.indexOf("DO NOT EDIT STUFF BELOW: IT IS AUTOMATICALLY GENERATED") != -1 && s.indexOf("\"")==-1) skip = true;
 432             if (s.indexOf("DO NOT EDIT STUFF ABOVE: IT IS AUTOMATICALLY GENERATED") != -1 && s.indexOf("\"")==-1) break;
 433             if (!skip) out.append(s+"\n");
 434         }
 435
 436         out.append("\n        // DO NOT EDIT STUFF BELOW: IT IS AUTOMATICALLY GENERATED\n");
 437         Tree<String> ts = new CharParser(MetaGrammar.make()).parse(new FileInputStream(args[0])).expand1();
 438
 439         //Forest<String> fs = new CharParser(make()).parse(new FileInputStream(args[0]));
 440         //System.out.println(fs.expand1());
 441
 442         //GraphViz gv = new GraphViz();
 443         //fs.toGraphViz(gv);
 444         //FileOutputStream fox = new FileOutputStream("out.dot");
 445         //gv.dump(fox);
 446         //fox.close();
 447
 448         ts.toJava(out);
 449         out.append("\n        // DO NOT EDIT STUFF ABOVE: IT IS AUTOMATICALLY GENERATED\n");
 450
 451         for(String s = br.readLine(); s != null; s = br.readLine()) out.append(s+"\n");
 452         br.close();
 453
 454         OutputStream os = new FileOutputStream(fileName);
 455         PrintWriter p = new PrintWriter(new OutputStreamWriter(os));
 456         p.println(out.toString());
 457         p.flush();
 458         os.close();
 459     }
 460
 461 }