gerrit.simantics Code Review - simantics/platform.git/blob

   1 package org.simantics.scl.compiler.internal.parsing.parser;
   2
   3 import java.io.Reader;
   4 import java.util.ArrayList;
   5 import java.util.Arrays;
   6 import java.util.List;
   7
   8 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
   9 import org.simantics.scl.compiler.common.precedence.Associativity;
  10 import org.simantics.scl.compiler.common.precedence.Precedence;
  11 import org.simantics.scl.compiler.constants.CharacterConstant;
  12 import org.simantics.scl.compiler.constants.StringConstant;
  13 import org.simantics.scl.compiler.elaboration.equation.EqBasic;
  14 import org.simantics.scl.compiler.elaboration.equation.EqGuard;
  15 import org.simantics.scl.compiler.elaboration.equation.Equation;
  16 import org.simantics.scl.compiler.elaboration.expressions.Case;
  17 import org.simantics.scl.compiler.elaboration.expressions.EApply;
  18 import org.simantics.scl.compiler.elaboration.expressions.EAsPattern;
  19 import org.simantics.scl.compiler.elaboration.expressions.EBinary;
  20 import org.simantics.scl.compiler.elaboration.expressions.EBinaryRightSide;
  21 import org.simantics.scl.compiler.elaboration.expressions.EBlock;
  22 import org.simantics.scl.compiler.elaboration.expressions.EConstant;
  23 import org.simantics.scl.compiler.elaboration.expressions.EEnforce;
  24 import org.simantics.scl.compiler.elaboration.expressions.EEntityTypeAnnotation;
  25 import org.simantics.scl.compiler.elaboration.expressions.EEquations;
  26 import org.simantics.scl.compiler.elaboration.expressions.EFieldAccess;
  27 import org.simantics.scl.compiler.elaboration.expressions.EIf;
  28 import org.simantics.scl.compiler.elaboration.expressions.EIntegerLiteral;
  29 import org.simantics.scl.compiler.elaboration.expressions.ELambda;
  30 import org.simantics.scl.compiler.elaboration.expressions.EListComprehension;
  31 import org.simantics.scl.compiler.elaboration.expressions.EListLiteral;
  32 import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
  33 import org.simantics.scl.compiler.elaboration.expressions.EMatch;
  34 import org.simantics.scl.compiler.elaboration.expressions.ERange;
  35 import org.simantics.scl.compiler.elaboration.expressions.ERealLiteral;
  36 import org.simantics.scl.compiler.elaboration.expressions.ERecord;
  37 import org.simantics.scl.compiler.elaboration.expressions.ESelect;
  38 import org.simantics.scl.compiler.elaboration.expressions.ESimpleLambda;
  39 import org.simantics.scl.compiler.elaboration.expressions.EStringLiteral;
  40 import org.simantics.scl.compiler.elaboration.expressions.ETransformation;
  41 import org.simantics.scl.compiler.elaboration.expressions.ETypeAnnotation;
  42 import org.simantics.scl.compiler.elaboration.expressions.EVar;
  43 import org.simantics.scl.compiler.elaboration.expressions.EVariable;
  44 import org.simantics.scl.compiler.elaboration.expressions.EViewPattern;
  45 import org.simantics.scl.compiler.elaboration.expressions.Expression;
  46 import org.simantics.scl.compiler.elaboration.expressions.GuardedExpression;
  47 import org.simantics.scl.compiler.elaboration.expressions.GuardedExpressionGroup;
  48 import org.simantics.scl.compiler.elaboration.expressions.Variable;
  49 import org.simantics.scl.compiler.elaboration.expressions.accessor.ExpressionAccessor;
  50 import org.simantics.scl.compiler.elaboration.expressions.accessor.FieldAccessor;
  51 import org.simantics.scl.compiler.elaboration.expressions.accessor.IdAccessor;
  52 import org.simantics.scl.compiler.elaboration.expressions.accessor.StringAccessor;
  53 import org.simantics.scl.compiler.elaboration.expressions.block.BindStatement;
  54 import org.simantics.scl.compiler.elaboration.expressions.block.CHRStatement;
  55 import org.simantics.scl.compiler.elaboration.expressions.block.ConstraintStatement;
  56 import org.simantics.scl.compiler.elaboration.expressions.block.GuardStatement;
  57 import org.simantics.scl.compiler.elaboration.expressions.block.LetStatement;
  58 import org.simantics.scl.compiler.elaboration.expressions.block.RuleStatement;
  59 import org.simantics.scl.compiler.elaboration.expressions.block.Statement;
  60 import org.simantics.scl.compiler.elaboration.expressions.list.ListAssignment;
  61 import org.simantics.scl.compiler.elaboration.expressions.list.ListGenerator;
  62 import org.simantics.scl.compiler.elaboration.expressions.list.ListGuard;
  63 import org.simantics.scl.compiler.elaboration.expressions.list.ListQualifier;
  64 import org.simantics.scl.compiler.elaboration.expressions.list.ListSeq;
  65 import org.simantics.scl.compiler.elaboration.expressions.list.ListThen;
  66 import org.simantics.scl.compiler.elaboration.expressions.records.FieldAssignment;
  67 import org.simantics.scl.compiler.elaboration.java.Builtins;
  68 import org.simantics.scl.compiler.elaboration.query.QAlternative;
  69 import org.simantics.scl.compiler.elaboration.query.QConjunction;
  70 import org.simantics.scl.compiler.elaboration.query.QDisjunction;
  71 import org.simantics.scl.compiler.elaboration.query.QNegation;
  72 import org.simantics.scl.compiler.elaboration.query.Query;
  73 import org.simantics.scl.compiler.elaboration.query.pre.QPreBinds;
  74 import org.simantics.scl.compiler.elaboration.query.pre.QPreEquals;
  75 import org.simantics.scl.compiler.elaboration.query.pre.QPreGuard;
  76 import org.simantics.scl.compiler.errors.Locations;
  77 import org.simantics.scl.compiler.internal.parsing.Symbol;
  78 import org.simantics.scl.compiler.internal.parsing.Token;
  79 import org.simantics.scl.compiler.internal.parsing.declarations.ConstructorAst;
  80 import org.simantics.scl.compiler.internal.parsing.declarations.DAnnotationAst;
  81 import org.simantics.scl.compiler.internal.parsing.declarations.DClassAst;
  82 import org.simantics.scl.compiler.internal.parsing.declarations.DDataAst;
  83 import org.simantics.scl.compiler.internal.parsing.declarations.DDerivingInstanceAst;
  84 import org.simantics.scl.compiler.internal.parsing.declarations.DDocumentationAst;
  85 import org.simantics.scl.compiler.internal.parsing.declarations.DEffectAst;
  86 import org.simantics.scl.compiler.internal.parsing.declarations.DFixityAst;
  87 import org.simantics.scl.compiler.internal.parsing.declarations.DImportJavaAst;
  88 import org.simantics.scl.compiler.internal.parsing.declarations.DInstanceAst;
  89 import org.simantics.scl.compiler.internal.parsing.declarations.DMappingRelationAst;
  90 import org.simantics.scl.compiler.internal.parsing.declarations.DModuleHeader;
  91 import org.simantics.scl.compiler.internal.parsing.declarations.DRelationAst;
  92 import org.simantics.scl.compiler.internal.parsing.declarations.DRuleAst;
  93 import org.simantics.scl.compiler.internal.parsing.declarations.DTypeAst;
  94 import org.simantics.scl.compiler.internal.parsing.declarations.DValueAst;
  95 import org.simantics.scl.compiler.internal.parsing.declarations.DValueTypeAst;
  96 import org.simantics.scl.compiler.internal.parsing.declarations.DeclarationAst;
  97 import org.simantics.scl.compiler.internal.parsing.declarations.FieldDescription;
  98 import org.simantics.scl.compiler.internal.parsing.declarations.FundepAst;
  99 import org.simantics.scl.compiler.internal.parsing.exceptions.SCLSyntaxErrorException;
 100 import org.simantics.scl.compiler.internal.parsing.types.TApplyAst;
 101 import org.simantics.scl.compiler.internal.parsing.types.TEffectAst;
 102 import org.simantics.scl.compiler.internal.parsing.types.TForAllAst;
 103 import org.simantics.scl.compiler.internal.parsing.types.TFunctionAst;
 104 import org.simantics.scl.compiler.internal.parsing.types.TListAst;
 105 import org.simantics.scl.compiler.internal.parsing.types.TPredAst;
 106 import org.simantics.scl.compiler.internal.parsing.types.TTupleAst;
 107 import org.simantics.scl.compiler.internal.parsing.types.TVarAst;
 108 import org.simantics.scl.compiler.internal.parsing.types.TypeAst;
 109 import org.simantics.scl.compiler.module.ImportDeclaration;
 110 import org.simantics.scl.compiler.types.Types;
 111
 112
 113 public class SCLParserImpl extends SCLParser {
 114
 115     private final SCLPostLexer lexer;
 116     private SCLParserOptions options;
 117
 118     public SCLParserImpl(Reader reader) {
 119         lexer = new SCLPostLexer(reader);
 120     }
 121
 122     public void setParserOptions(SCLParserOptions options) {
 123         this.options = options;
 124         lexer.setParserOptions(options);
 125     }
 126
 127     public boolean isEmpty() throws Exception {
 128         return lexer.peekToken().id == SCLTerminals.EOF;
 129     }
 130
 131     @Override
 132     protected Token nextToken() {
 133         try {
 134             Token token = lexer.nextToken();
 135             /*System.out.println("TOKEN " + token.text + " (" + TERMINAL_NAMES[token.id] + ")" +
 136                     " ["
 137                     + Locations.beginOf(token.location) + ".."
 138                     + Locations.endOf(token.location) + "]");*/
 139             return token;
 140         } catch(Exception e) {
 141             if(e instanceof RuntimeException)
 142                 throw (RuntimeException)e;
 143             else
 144                 throw new RuntimeException(e);
 145         }
 146     }
 147
 148     @Override
 149     protected Object reduceDeclarations() {
 150         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2);
 151         for(int i=1;i<length();i+=2)
 152             declarations.add((DeclarationAst)get(i));
 153         return declarations;
 154     }
 155
 156     @Override
 157     protected Object reduceModule() {
 158         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2+1);
 159         for(int i=0;i<length();i+=2) {
 160             DeclarationAst declaration = (DeclarationAst)get(i);
 161             if(declaration == null)
 162                 throw new NullPointerException();
 163             declarations.add(declaration);
 164         }
 165         return declarations;
 166     }
 167
 168     @Override
 169     protected Object reduceModuleHeader() {
 170         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
 171         for(int i=0;i<fields.length;++i)
 172             fields[i] = (FieldAssignment)get(2+i*2);
 173         return new DModuleHeader(fields);
 174     }
 175
 176     @Override
 177     protected Object reduceLocalTypeAnnotation() {
 178         if(length() == 1)
 179             return get(0);
 180         return new ETypeAnnotation((Expression)get(0), (TypeAst)get(2));
 181     }
 182
 183     @Override
 184     protected Object reduceTypeAnnotation() {
 185         EVar[] names = new EVar[length()/2];
 186         for(int i=0;i<names.length;++i)
 187             names[i] = (EVar)get(i*2);
 188         return new DValueTypeAst(
 189                 names,
 190                 (TypeAst)get(length()-1)
 191                 );
 192     }
 193
 194     @Override
 195     protected Object reduceValueDefinition() {
 196         Expression rhs = (Expression)get(1);
 197         return new DValueAst((Expression)get(0), rhs);
 198     }
 199
 200     @Override
 201     protected Object reduceDataDefinition() {
 202         int i=2;
 203         ArrayList<String> parameters = new ArrayList<String>();
 204         while(i < length()) {
 205             Token token = (Token)get(i++);
 206             if(token.id != SCLTerminals.ID)
 207                 break;
 208             parameters.add(token.text);
 209         }
 210         ArrayList<ConstructorAst> constructors = new ArrayList<ConstructorAst>();
 211         for(;i < length();i+=2)
 212             constructors.add((ConstructorAst)get(i));
 213         return new DDataAst(
 214                 ((Token)get(1)).text,
 215                 parameters.toArray(new String[parameters.size()]),
 216                 constructors.toArray(new ConstructorAst[constructors.size()]),
 217                 new String[0]
 218                 );
 219     }
 220
 221     @Override
 222     protected Object reduceTypeDefinition() {
 223         int i=2;
 224         ArrayList<String> parameters = new ArrayList<String>();
 225         while(true) {
 226             Token token = (Token)get(i++);
 227             if(token.id != SCLTerminals.ID)
 228                 break;
 229             parameters.add(token.text);
 230         }
 231         return new DTypeAst(
 232                 ((Token)get(1)).text,
 233                 parameters.toArray(new String[parameters.size()]),
 234                 (TypeAst)get(i)
 235                 );
 236     }
 237
 238     @SuppressWarnings("unchecked")
 239     @Override
 240     protected Object reduceClassDefinition() {
 241         int i=1;
 242         ArrayList<TypeAst> context;
 243         if(get(i) instanceof Token)
 244             context = new ArrayList<TypeAst>(0);
 245         else
 246             context = (ArrayList<TypeAst>)get(i++);
 247         String name = ((Token)get(i++)).text;
 248         ArrayList<String> parameters = new ArrayList<String>();
 249         while(i < length()) {
 250             Token token = (Token)get(i);
 251             if(token.id != SCLTerminals.ID)
 252                 break;
 253             parameters.add(token.text);
 254             ++i;
 255         }
 256         ArrayList<DeclarationAst> declarations = null;
 257         FundepAst[] fundeps = FundepAst.EMPTY_ARRAY;
 258         while(i < length()) {
 259             Token token = (Token)get(i++);
 260             if(token.id == SCLTerminals.WHERE) {
 261                 declarations = (ArrayList<DeclarationAst>)get(i++);
 262             }
 263             else if(token.id == SCLTerminals.BAR) {
 264                 fundeps = (FundepAst[])get(i++);
 265             }
 266             else
 267                 throw new InternalCompilerError();
 268         }
 269         return new DClassAst(context, name,
 270                 parameters.toArray(new String[parameters.size()]),
 271                 fundeps,
 272                 declarations);
 273     }
 274
 275     @Override
 276     protected Object reduceFundep() {
 277         String[] from = new String[length()-2];
 278         for(int i=0;i<from.length;++i)
 279             from[i] = ((Token)get(i)).text;
 280         String to = ((Token)get(length()-1)).text;
 281         return new FundepAst(from, to);
 282     }
 283
 284     @Override
 285     protected Object reduceFundeps() {
 286         FundepAst[] fundeps = new FundepAst[(length()+1)/2];
 287         for(int i=0;i<fundeps.length;++i)
 288             fundeps[i] = (FundepAst)get(i*2);
 289         return fundeps;
 290     }
 291
 292     @SuppressWarnings("unchecked")
 293     @Override
 294     protected Object reduceInstanceDefinition() {
 295         int i=1;
 296         ArrayList<TypeAst> context;
 297         if(get(i) instanceof Token)
 298             context = new ArrayList<TypeAst>(0);
 299         else
 300             context = (ArrayList<TypeAst>)get(i++);
 301         Token nameToken = (Token)get(i++);
 302         EVar name = new EVar(nameToken.location, nameToken.text);
 303         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 304         while(i < length()) {
 305             Object symbol = get(i++);
 306             if(symbol instanceof Token)
 307                 break;
 308             parameters.add((TypeAst)symbol);
 309         }
 310         ArrayList<DeclarationAst> declarations = null;
 311         if(i < length())
 312             declarations = (ArrayList<DeclarationAst>)get(i);
 313         return new DInstanceAst(context, name,
 314                 parameters.toArray(new TypeAst[parameters.size()]),
 315                 declarations);
 316     }
 317
 318     @SuppressWarnings("unchecked")
 319     @Override
 320     protected Object reduceDerivingInstanceDefinition() {
 321         int i=2;
 322         ArrayList<TypeAst> context;
 323         if(get(i) instanceof Token)
 324             context = new ArrayList<TypeAst>(0);
 325         else
 326             context = (ArrayList<TypeAst>)get(i++);
 327         Token nameToken = (Token)get(i++);
 328         EVar name = new EVar(nameToken.location, nameToken.text);
 329         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 330         while(i < length()) {
 331             Object symbol = get(i++);
 332             parameters.add((TypeAst)symbol);
 333         }
 334         return new DDerivingInstanceAst(context, name,
 335                 parameters.toArray(new TypeAst[parameters.size()]));
 336     }
 337
 338     @Override
 339     protected Object reduceDocumentationString() {
 340         return new DDocumentationAst(((Token)get(1)).text);
 341     }
 342
 343     @Override
 344     protected Object reduceAnnotation() {
 345         ArrayList<Expression> parameters = new ArrayList<Expression>(length()-1);
 346         for(int i=1;i<length();++i)
 347             parameters.add((Expression)get(i));
 348         return new DAnnotationAst((Token)get(0), parameters);
 349     }
 350
 351     @Override
 352     protected Object reducePrecedenceDefinition() {
 353         EVar[] symbols = new EVar[length()/2];
 354         for(int i=0;i<symbols.length;++i)
 355             symbols[i] = (EVar)get(2*i + 2);
 356         Associativity associativity;
 357         Token token = (Token)get(0);
 358         if(token.text.equals("infixl"))
 359             associativity = Associativity.LEFT;
 360         else if(token.text.equals("infixr"))
 361             associativity = Associativity.RIGHT;
 362         else
 363             associativity = Associativity.NONASSOC;
 364         return new DFixityAst(
 365                 new Precedence(
 366                         Integer.parseInt(((Token)get(1)).text),
 367                         associativity),
 368                         symbols);
 369     }
 370
 371     @Override
 372     protected Object reduceImport() {
 373         // (AS ID)? importSpec?
 374         int pos = 0;
 375         String importKeyword = ((Token)get(pos++)).text; // (IMPORT | INCLUDE)
 376         ++pos; // BEGIN_STRING
 377         String moduleName = ((Token)get(pos++)).text; // END_STRING
 378         String localName = "";
 379         if(pos < length()) {
 380             Object temp = get(pos);
 381             if(temp instanceof Token) {
 382                 Token token = (Token)temp;
 383                 if(token.id == SCLTerminals.AS) {
 384                     ++pos; // AS
 385                     localName = ((Token)get(pos++)).text; // ID
 386                 }
 387             }
 388         }
 389         ImportDeclaration.ImportSpec spec = ImportDeclaration.DEFAULT_SPEC;
 390         if(pos < length())
 391             spec = (ImportDeclaration.ImportSpec)get(pos++);
 392         return new ImportDeclaration(moduleName, localName,
 393                         importKeyword.equals("include"),
 394                         spec);
 395     }
 396
 397     @Override
 398     protected Object reduceJustImport() {
 399         return get(0);
 400     }
 401
 402     @SuppressWarnings("unchecked")
 403     @Override
 404     protected Object reduceImportJava() {
 405         return new DImportJavaAst(((Token)get(2)).text, (ArrayList<DeclarationAst>)get(4));
 406     }
 407
 408     @Override
 409     protected Object reduceEffectDefinition() {
 410         return new DEffectAst(
 411                 ((Token)get(1)).text,
 412                 ((Token)get(3)).text,
 413                 ((Token)get(5)).text);
 414     }
 415
 416     @Override
 417     protected Object reduceVarId() {
 418         return new EVar(((Token)get(0)).text);
 419     }
 420
 421     @Override
 422     protected Object reduceEscapedSymbol() {
 423         return new EVar(((Token)get(0)).text);
 424     }
 425
 426     @Override
 427     protected Object reduceTupleTypeConstructor() {
 428         return new TVarAst(Types.tupleConstructor(length()-1).name);
 429     }
 430
 431     @Override
 432     protected Object reduceArrow() {
 433         int i=length()-1;
 434         TypeAst result = (TypeAst)get(i);
 435         i-=2;
 436         while(i >= 0) {
 437             if( ((Token)get(i+1)).text.equals("=>") )
 438                 result = new TPredAst((TypeAst)get(i), result);
 439             else
 440                 result = new TFunctionAst((TypeAst)get(i), result);
 441             i-=2;
 442         }
 443         return result;
 444     }
 445
 446     @Override
 447     protected Object reduceBinary() {
 448         if(length() == 1)
 449             return get(0);
 450         int i=0;
 451         EVar negation = null;
 452         if(get(i) instanceof Token) {
 453             Token token = (Token)get(i++);
 454             negation = new EVar(token.location, token.text);
 455         }
 456         EBinary binary = new EBinary((Expression)get(i++), negation);
 457         while(i < length()) {
 458             EVar operator = (EVar)get(i++);
 459             Expression right = (Expression)get(i++);
 460             binary.rights.add(new EBinaryRightSide(operator, right));
 461         }
 462         return binary;
 463     }
 464
 465     @Override
 466     protected Object reduceSimpleRhs() {
 467         if(length() == 2)
 468             return get(1);
 469         else {
 470             EBlock block = (EBlock)get(3);
 471             Expression expression = (Expression)get(1);
 472             block.addStatement(new GuardStatement(expression));
 473             block.location = Locations.location(Locations.beginOf(expression.location), Locations.endOf(block.location));
 474             return block;
 475         }
 476     }
 477
 478     private GuardedExpressionGroup reduceGuardedExpressionGroup(int length) {
 479         GuardedExpression[] expressions = new GuardedExpression[length];
 480         for(int i=0;i<expressions.length;++i) {
 481             expressions[i] = (GuardedExpression)get(i);
 482         }
 483         return new GuardedExpressionGroup(expressions);
 484     }
 485
 486     @Override
 487     protected Object reduceGuardedRhs() {
 488         int length = length();
 489         if(length > 2 && get(length-2) instanceof Token) {
 490             EBlock block = (EBlock)get(length-1);
 491             block.addStatement(new GuardStatement(reduceGuardedExpressionGroup(length-2)));
 492             block.location = Locations.NO_LOCATION;
 493             return block;
 494         }
 495         else
 496             return reduceGuardedExpressionGroup(length);
 497     }
 498
 499     @Override
 500     protected Object reduceStatements() {
 501         EBlock block = new EBlock();
 502         if(length() > 2)
 503             for(int i=1;i<length();i+=2)
 504                 block.addStatement((Statement)get(i));
 505         return block;
 506     }
 507
 508     @Override
 509     protected Object reduceConstructor() {
 510         int idPos;
 511         for(idPos=0;idPos<length();idPos+=2)
 512             if(((Token)get(idPos)).id == SCLTerminals.ID)
 513                 break;
 514         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
 515         for(int i=0;i<idPos/2;++i)
 516             annotations[i] = new DAnnotationAst((Token)get(i*2),
 517                     Arrays.asList((Expression)get(i*2+1)));
 518         TypeAst[] parameters = new TypeAst[length()-idPos-1];
 519         for(int i=0;i<parameters.length;++i)
 520             parameters[i] = (TypeAst)get(i+idPos+1);
 521         return new ConstructorAst(annotations, ((Token)get(idPos)).text, parameters, null);
 522     }
 523
 524     @Override
 525     protected Object reduceContext() {
 526         ArrayList<TypeAst> result = new ArrayList<TypeAst>(length()/2-1);
 527         for(int i=1;i<length()-2;i+=2)
 528             result.add((TypeAst)get(i));
 529         return result;
 530     }
 531
 532     @Override
 533     protected Object reduceTypeVar() {
 534         return new TVarAst(((Token)get(0)).text);
 535     }
 536
 537     @Override
 538     protected Object reduceTupleType() {
 539         if(length() == 2)
 540             return new TTupleAst(TypeAst.EMPTY_ARRAY);
 541         if(length() == 3) {
 542             Symbol sym = (Symbol)get(1);
 543             sym.location = Locations.NO_LOCATION;
 544             return sym;
 545         }
 546         int dim = length()/2;
 547         TypeAst[] parameters = new TypeAst[dim];
 548         for(int i=0;i<dim;++i)
 549             parameters[i] = (TypeAst)get(i*2+1);
 550         return new TTupleAst(parameters);
 551     }
 552
 553     @Override
 554     protected Object reduceListType() {
 555         return new TListAst((TypeAst)get(1));
 556     }
 557
 558     @Override
 559     protected Object reduceListTypeConstructor() {
 560         return new TVarAst("[]");
 561     }
 562
 563     @Override
 564     protected Object reduceTupleConstructor() {
 565         return new EVar(Types.tupleConstructor(length()-1).name);
 566     }
 567
 568     @Override
 569     protected Object reduceVar() {
 570         return get(0);
 571     }
 572
 573     @Override
 574     protected Object reduceBlank() {
 575         return new EVar("_");
 576     }
 577
 578     @Override
 579     protected Object reduceInteger() {
 580         return new EIntegerLiteral(((Token)get(0)).text);
 581     }
 582
 583     @Override
 584     protected Object reduceFloat() {
 585         return new ERealLiteral(((Token)get(0)).text);
 586     }
 587
 588     @Override
 589     protected Object reduceString() {
 590         return get(0);
 591     }
 592
 593     @Override
 594     protected Object reduceChar() {
 595         String text = ((Token)get(0)).text;
 596         char c = text.charAt(text.length()-2);
 597         if(text.length() == 4) {
 598             switch(c) {
 599             case 'n': c = '\n'; break;
 600             case 't': c = '\t'; break;
 601             case 'b': c = '\b'; break;
 602             case 'f': c = '\f'; break;
 603             case 'r': c = '\r'; break;
 604             }
 605         }
 606         return new ELiteral(new CharacterConstant(c));
 607     }
 608
 609     @Override
 610     protected Object reduceTuple() {
 611         if(length() == 2)
 612             return new EConstant(Builtins.TUPLE_CONSTRUCTORS[0]);
 613         if(length() == 3) {
 614             Symbol sym = (Symbol)get(1);
 615             sym.location = Locations.NO_LOCATION;
 616             return sym;
 617         }
 618         int dim = length()/2;
 619         Expression[] parameters = new Expression[dim];
 620         for(int i=0;i<dim;++i)
 621             parameters[i] = (Expression)get(i*2+1);
 622         EConstant tupleConstructor = new EConstant(Builtins.TUPLE_CONSTRUCTORS[dim]);
 623         tupleConstructor.location = Locations.location(
 624                 Locations.beginOf(((Token)get(0)).location),
 625                 Locations.endOf(((Token)get(length()-1)).location));
 626         return new EApply(tupleConstructor, parameters);
 627     }
 628
 629     public static Expression rightSection(EVar op, Expression e) {
 630         long loc = Locations.combine(op.location, e.location);
 631         Variable var = new Variable("rightSectionTemp");
 632         return new ESimpleLambda(loc, var,
 633                 new EApply(loc, op, new EVariable(loc, var), e));
 634     }
 635
 636     @Override
 637     protected Object reduceRightSection() {
 638         Variable var = new Variable("rightSectionTemp");
 639         long loc = Locations.combine(((Token)get(0)).location, ((Token)get(length()-1)).location);
 640         EVar symbol = (EVar)get(1);
 641         return new ESimpleLambda(var,
 642                 new EApply(loc, symbol,
 643                         new EVariable(loc, var), (Expression)get(2)));
 644     }
 645
 646     @Override
 647     protected Object reduceLeftSection() {
 648         return new EApply((EVar)get(2), (Expression)get(1));
 649     }
 650
 651     @Override
 652     protected Object reduceListLiteral() {
 653         if(length() == 2)
 654             return new EListLiteral(Expression.EMPTY_ARRAY);
 655         int dim = length()/2;
 656         Expression[] components = new Expression[dim];
 657         for(int i=0;i<dim;++i)
 658             components[i] = (Expression)get(i*2+1);
 659         return new EListLiteral(components);
 660     }
 661
 662     @Override
 663     protected Object reduceRange() {
 664         return new ERange(
 665                 (Expression)get(1),
 666                 (Expression)get(3)
 667                 );
 668     }
 669
 670     @Override
 671     protected Object reduceListComprehension() {
 672         ListQualifier qualifier = (ListQualifier)get(3);
 673         for(int i=5;i<length();i+=2) {
 674             ListQualifier right = (ListQualifier)get(i);
 675             if(right instanceof ListThen) {
 676                 ((ListThen) right).setLeft(qualifier);
 677                 qualifier = right;
 678             }
 679             else
 680                 qualifier = new ListSeq(qualifier, right);
 681         }
 682         return new EListComprehension((Expression)get(1), qualifier);
 683     }
 684
 685     @Override
 686     protected Object reduceAs() {
 687         Token id = (Token)get(0);
 688         return new EAsPattern(new EVar(id.location, id.text), (Expression)get(2));
 689     }
 690
 691     @Override
 692     protected Object reduceGuardedExpEq() {
 693         Expression[] guards = new Expression[length()/2-1];
 694         for(int i=0;i<guards.length;++i)
 695             guards[i] = (Expression)get(i*2+1);
 696         return new GuardedExpression(guards, (Expression)get(length()-1));
 697     }
 698
 699     @Override
 700     protected Object reduceLambda() {
 701         Expression[] patterns = new Expression[length()-3];
 702         for(int i=0;i<patterns.length;++i)
 703             patterns[i] = (Expression)get(i+1);
 704         Case case_ = new Case(patterns, (Expression)get(length()-1));
 705         case_.setLhs(Locations.combine(patterns[0].location, patterns[patterns.length-1].location));
 706         return new ELambda(case_);
 707     }
 708
 709     @Override
 710     protected Object reduceLambdaMatch() {
 711         Case[] cases = new Case[length()/2-1];
 712         for(int i=0;i<cases.length;++i)
 713             cases[i] = (Case)get(i*2+2);
 714         return new ELambda(cases);
 715     }
 716
 717     @Override
 718     protected Object reduceLet() {
 719         EBlock block = (EBlock)get(1);
 720         Expression expression = (Expression)get(3);
 721         block.addStatement(new GuardStatement(expression));
 722         Token letToken = (Token)get(0);
 723         block.location = Locations.location(
 724                 Locations.beginOf(letToken.location),
 725                 Locations.endOf(expression.location));
 726         return block;
 727     }
 728
 729     @Override
 730     protected Object reduceIf() {
 731         return new EIf(
 732                 (Expression)get(1),
 733                 (Expression)get(3),
 734                 length() == 6 ? (Expression)get(5) : null);
 735     }
 736
 737     @Override
 738     protected Object reduceMatch() {
 739         Case[] cases = new Case[length()/2-2];
 740         for(int i=0;i<cases.length;++i)
 741             cases[i] = (Case)get(i*2+4);
 742         return new EMatch((Expression)get(1), cases);
 743     }
 744
 745     @Override
 746     protected Object reduceDo() {
 747         EBlock block = (EBlock)get(1);
 748         Token doToken = (Token)get(0);
 749         block.setMonadic( doToken.text.equals("mdo") );
 750         block.location = Locations.location(Locations.beginOf(doToken.location), Locations.endOf(block.location));
 751         return block;
 752     }
 753
 754     @Override
 755     protected Object reduceSelect() {
 756         return new ESelect(((Token)get(0)).id, (Expression)get(1), new QConjunction((Query[])get(3)));
 757     }
 758
 759     @Override
 760     protected Object reduceEnforce() {
 761         return new EEnforce(new QConjunction((Query[])get(1)));
 762     }
 763
 764     @Override
 765     protected Object reduceApply() {
 766         if(length() == 1)
 767             return get(0);
 768         Expression[] parameters = new Expression[length()-1];
 769         for(int i=0;i<parameters.length;++i)
 770             parameters[i] = (Expression)get(i+1);
 771         return new EApply((Expression)get(0), parameters);
 772     }
 773
 774     @Override
 775     protected Object reduceSymbol() {
 776         return new EVar(((Token)get(0)).text);
 777     }
 778
 779     @Override
 780     protected Object reduceEscapedId() {
 781         return new EVar(((Token)get(0)).text);
 782     }
 783
 784     @Override
 785     protected Object reduceMinus() {
 786         return new EVar(((Token)get(0)).text);
 787     }
 788
 789     @Override
 790     protected Object reduceLess() {
 791         return new EVar(((Token)get(0)).text);
 792     }
 793
 794     @Override
 795     protected Object reduceGreater() {
 796         return new EVar(((Token)get(0)).text);
 797     }
 798
 799     @Override
 800     protected Object reduceDot() {
 801         return new EVar(((Token)get(0)).text);
 802     }
 803
 804     @Override
 805     protected Object reduceCase() {
 806         return new Case((Expression)get(0), (Expression)get(1));
 807     }
 808
 809     @Override
 810     protected Object reduceGuardQualifier() {
 811         return new ListGuard((Expression)get(0));
 812     }
 813
 814     @Override
 815     protected Object reduceLetQualifier() {
 816         return new ListAssignment((Expression)get(0), (Expression)get(2));
 817     }
 818
 819     @Override
 820     protected Object reduceBindQualifier() {
 821         return new ListGenerator((Expression)get(0), (Expression)get(2));
 822     }
 823
 824     @Override
 825     protected Object reduceThenQualifier() {
 826         return new ListThen((Expression)get(1), length()==4 ? (Expression)get(3) : null);
 827     }
 828
 829     @Override
 830     protected Object reduceGuardStatement() {
 831         return new GuardStatement((Expression)get(0));
 832     }
 833
 834     @Override
 835     protected Object reduceLetStatement() {
 836         return new LetStatement((Expression)get(0), (Expression)get(1));
 837     }
 838
 839     @Override
 840     protected Object reduceBindStatement() {
 841         return new BindStatement((Expression)get(0), (Expression)get(2));
 842     }
 843
 844     @Override
 845     protected Object reduceSimpleCaseRhs() {
 846         return get(1);
 847     }
 848
 849     @Override
 850     protected Object reduceGuardedCaseRhs() {
 851         GuardedExpression[] expressions = new GuardedExpression[length()];
 852         for(int i=0;i<expressions.length;++i)
 853             expressions[i] = (GuardedExpression)get(i);
 854         return new GuardedExpressionGroup(expressions);
 855     }
 856
 857     @Override
 858     protected Object reduceGuardedExpArrow() {
 859         Expression[] guards = new Expression[length()/2-1];
 860         for(int i=0;i<guards.length;++i)
 861             guards[i] = (Expression)get(i*2+1);
 862         return new GuardedExpression(guards, (Expression)get(length()-1));
 863     }
 864
 865     @Override
 866     protected Object reduceEffect() {
 867         ArrayList<TypeAst> effects = new ArrayList<TypeAst>(length()/2-1);
 868         for(int i=1;i<length()-1;i+=2) {
 869             Token token = (Token)get(i);
 870             TVarAst ast = new TVarAst(token.text);
 871             ast.location = token.location;
 872             effects.add(ast);
 873         }
 874         return new TEffectAst(effects, (TypeAst)get(length()-1));
 875     }
 876
 877     @Override
 878     protected Object reduceJustEtype() {
 879         return get(0);
 880     }
 881
 882     @Override
 883     protected Object reduceForAll() {
 884         String[] vars = new String[length()-3];
 885         for(int i=0;i<vars.length;++i)
 886             vars[i] = ((Token)get(i+1)).text;
 887         return new TForAllAst(vars, (TypeAst)get(length()-1));
 888     }
 889
 890     @Override
 891     protected Object reduceApplyType() {
 892         TypeAst[] parameters = new TypeAst[length()-1];
 893         for(int i=0;i<parameters.length;++i)
 894             parameters[i] = (TypeAst)get(i+1);
 895         return new TApplyAst((TypeAst)get(0), parameters);
 896     }
 897
 898     @SuppressWarnings("unchecked")
 899     @Override
 900     protected void postReduce(Object reduced) {
 901         if(!(reduced instanceof Symbol))
 902             return;
 903         Symbol sym = (Symbol)reduced;
 904         if(sym.location != Locations.NO_LOCATION || length() == 0)
 905             return;
 906         Object first = get(0);
 907         if(!(first instanceof Symbol)) {
 908             if(first instanceof List) {
 909                 List<Object> ll = (List<Object>)first;
 910                 first = ll.get(0);
 911             }
 912             else {
 913                 Object[] ll = (Object[])first;
 914                 if(ll.length > 0)
 915                     first = ll[0];
 916                 else
 917                     first = get(1);
 918             }
 919         }
 920         Object last = get(length()-1);
 921         if(!(last instanceof Symbol)) {
 922             if(last instanceof List) {
 923                 List<Object> ll = (List<Object>)last;
 924                 last = ll.get(ll.size()-1);
 925             }
 926             else {
 927                 Object[] ll = (Object[])last;
 928                 if(ll.length > 0)
 929                     last = ll[ll.length-1];
 930                 else
 931                     last = get(length()-2);
 932             }
 933         }
 934         sym.location = (((Symbol)first).location & 0xffffffff00000000L)
 935                 | (((Symbol)last).location & 0xffffffffL);
 936         /*for(int i=0;i<length();++i) {
 937             Object obj = get(i);
 938             System.out.print(obj.getClass().getSimpleName());
 939             if(obj instanceof Token) {
 940                 Token t = (Token)obj;
 941                 System.out.print("(" + t.text + ")");
 942             }
 943             if(obj instanceof Symbol) {
 944                 Symbol s = (Symbol)obj;
 945                 System.out.print("["+ Locations.beginOf(s.location) + "-" + Locations.endOf(s.location) + "]");
 946             }
 947             System.out.print(" ");
 948         }
 949         System.out.println("-> " + reduced.getClass().getSimpleName() + " " +
 950                 Locations.beginOf(sym.location) + "-" + Locations.endOf(sym.location));*/
 951     }
 952
 953     @Override
 954     protected RuntimeException syntaxError(Token token, String description) {
 955         throw new SCLSyntaxErrorException(token.location, description);
 956     }
 957
 958     @Override
 959     protected Object reduceIdAccessor() {
 960         return new IdAccessor(((Token)get(0)).text);
 961     }
 962
 963     @Override
 964     protected Object reduceStringAccessor() {
 965         return new StringAccessor(((Token)get(1)).text);
 966     }
 967
 968     @Override
 969     protected Object reduceExpAccessor() {
 970         return new ExpressionAccessor((Expression)get(1));
 971     }
 972
 973     @Override
 974     protected Object reduceFieldAccess() {
 975         if(length() == 1)
 976             return get(0);
 977         FieldAccessor[] accessors = new FieldAccessor[length()/2];
 978         for(int i=0;i<accessors.length;++i) {
 979             FieldAccessor accessor = (FieldAccessor)get(i*2+2);
 980             accessor.accessSeparator = ((Token)get(i*2+1)).text.charAt(0);
 981             accessors[i] = accessor;
 982         }
 983         return new EFieldAccess((Expression)get(0), accessors);
 984     }
 985
 986     @Override
 987     protected Object reduceQueryBlock() {
 988         if(length() == 2)
 989             return Query.EMPTY_ARRAY;
 990         Query[] queries = new Query[length()/2];
 991         for(int i=0;i<queries.length;++i)
 992             queries[i] = (Query)get(2*i+1);
 993         return queries;
 994     }
 995
 996     @Override
 997     protected Object reduceGuardQuery() {
 998         return new QPreGuard((Expression)get(0));
 999     }
1000
1001     @Override
1002     protected Object reduceEqualsQuery() {
1003         return new QPreEquals((Expression)get(0), (Expression)get(2));
1004     }
1005
1006     @Override
1007     protected Object reduceBindQuery() {
1008         return new QPreBinds((Expression)get(0), (Expression)get(2));
1009     }
1010
1011     @Override
1012     protected Object reduceCompositeQuery() {
1013         Query[] queries = (Query[])get(1);
1014         switch(((Token)get(0)).text.charAt(1)) {
1015         case '&': return new QConjunction(queries);
1016         case '|': return new QDisjunction(queries);
1017         case '!': return new QNegation(new QConjunction(queries));
1018         case '?': return new QAlternative(queries);
1019         default: throw new InternalCompilerError();
1020         }
1021     }
1022
1023     @Override
1024     protected Object reduceRuleStatement() {
1025         return new RuleStatement((Expression)get(0), new QConjunction((Query[])get(2)));
1026     }
1027
1028     @Override
1029     protected Object reduceEntityTypeAnnotation() {
1030         return new EEntityTypeAnnotation((Expression)get(0), (Token)get(2),
1031                 length() > 3
1032                 ? new QConjunction((Query[])get(length()-1))
1033                 : null);
1034     }
1035
1036     @Override
1037     protected Object reduceHashedId() {
1038         return new EVar("#" + ((Token)get(1)).text);
1039     }
1040
1041     @Override
1042     protected Object reduceStringLiteral() {
1043         int expCount = length()/3;
1044         if(expCount == 0)
1045             return new ELiteral(new StringConstant(((Token)get(1)).text));
1046         else {
1047             String[] strings = new String[expCount+1];
1048             Expression[] expressions = new Expression[expCount];
1049             for(int i=0;i<expCount;++i) {
1050                 strings[i] = ((Token)get(i*3+1)).text;
1051                 expressions[i] = (Expression)get(i*3+2);
1052             }
1053             strings[expCount] = ((Token)get(expCount*3+1)).text;
1054             return new EStringLiteral(strings, expressions);
1055         }
1056     }
1057
1058     @Override
1059     protected Object reduceOneCommand() {
1060         return null;
1061     }
1062
1063     @Override
1064     protected Object reduceManyCommands() {
1065         return null;
1066     }
1067
1068     @Override
1069     protected Object reduceStatementCommand() {
1070         // to be extended in subclasses
1071         return null;
1072     }
1073
1074     @Override
1075     protected Object reduceImportCommand() {
1076         // to be extended in subclasses
1077         return null;
1078     }
1079
1080     @Override
1081     protected Object reduceImportValueItem() {
1082         return new EVar(((Token)get(0)).text);
1083     }
1084
1085     @Override
1086     protected Object reduceImportHiding() {
1087         EVar[] values = new EVar[(length()-2)/2];
1088         for(int i=0;i<values.length;++i)
1089             values[i] = (EVar)get(i*2+2);
1090         return new ImportDeclaration.ImportSpec(true, values);
1091     }
1092
1093     @Override
1094     protected Object reduceImportShowing() {
1095         EVar[] values = new EVar[(length()-1)/2];
1096         for(int i=0;i<values.length;++i)
1097             values[i] = (EVar)get(i*2+1);
1098         return new ImportDeclaration.ImportSpec(false, values);
1099     }
1100
1101     @Override
1102     protected Object reduceRuleDeclarations() {
1103         ArrayList<Object> declarations = new ArrayList<Object>(length()/2);
1104         for(int i=1;i<length();i+=2)
1105             declarations.add((Object)get(i));
1106         return declarations;
1107     }
1108
1109     private static final String[] EMPTY_STRING_ARRAY = new String[0];
1110
1111     @SuppressWarnings("unchecked")
1112     @Override
1113     protected Object reduceRuleDefinition() {
1114         String[] extendsNames = EMPTY_STRING_ARRAY;
1115         if(length() >= 6) {
1116             int extendsCount = (length() - 4) / 2;
1117             extendsNames = new String[extendsCount];
1118             for(int i=0;i<extendsCount;++i)
1119                 extendsNames[i] = ((Token)get(3+i*2)).text;
1120         }
1121
1122         DRuleAst rule = new DRuleAst(
1123                 ((Token)get(0)).id == SCLTerminals.ABSTRACT_RULE,
1124                 ((Token)get(1)).text,
1125                 extendsNames);
1126
1127         ArrayList<Object> ruleDeclarations = (ArrayList<Object>)get(length()-1);
1128         ArrayList<Query> section = null;
1129         for(Object decl : ruleDeclarations) {
1130             if(decl instanceof DAnnotationAst) {
1131                 DAnnotationAst annotation = (DAnnotationAst)decl;
1132                 section = rule.getSection(annotation.id.text.substring(1));
1133             }
1134             else if(decl instanceof Query) {
1135                 if(section == null)
1136                     section = rule.getSection("when");
1137                 section.add((Query)decl);
1138             }
1139             else
1140                 throw new InternalCompilerError();
1141         }
1142         return rule;
1143     }
1144
1145     @Override
1146     protected Object reduceQueryRuleDeclaration() {
1147         return get(0);
1148     }
1149
1150     @Override
1151     protected Object reduceMappingRelationDefinition() {
1152         TypeAst[] types = new TypeAst[length()-2];
1153         for(int i=0;i<types.length;++i)
1154             types[i] = (TypeAst)get(i+2);
1155         return new DMappingRelationAst(
1156                 ((Token)get(1)).text,
1157                 types);
1158     }
1159
1160     @Override
1161     protected Object reduceTransformation() {
1162         return new ETransformation(
1163                 ((Token)get(1)).text,
1164                 new QConjunction((Query[])get(3))
1165                 );
1166     }
1167
1168     @SuppressWarnings("unchecked")
1169     @Override
1170     protected Object reduceRelationDefinition() {
1171         return new DRelationAst((Expression)get(0),
1172                 ((ArrayList<Object>)get(2)).toArray());
1173     }
1174
1175     @Override
1176     protected Object reduceRecord() {
1177         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
1178         for(int i=0;i<fields.length;++i)
1179             fields[i] = (FieldAssignment)get(2+i*2);
1180         return new ERecord((Token)get(0), fields);
1181     }
1182
1183     @Override
1184     protected Object reduceField() {
1185         return new FieldAssignment(((Token)get(0)).text, (Expression)get(2));
1186     }
1187
1188     @Override
1189     protected Object reduceFieldShorthand() {
1190         return new FieldAssignment(((Token)get(0)).text, null);
1191     }
1192
1193     @Override
1194     protected Object reduceRecordConstructor() {
1195         int idPos;
1196         for(idPos=0;idPos<length();idPos+=2)
1197             if(((Token)get(idPos)).id == SCLTerminals.ID)
1198                 break;
1199         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
1200         for(int i=0;i<idPos/2;++i)
1201             annotations[i] = new DAnnotationAst((Token)get(i*2),
1202                     Arrays.asList((Expression)get(i*2+1)));
1203         TypeAst[] parameters = new TypeAst[(length()-idPos-1)/2];
1204         String[] fieldNames = new String[parameters.length];
1205         for(int i=0;i<parameters.length;++i) {
1206             FieldDescription fieldDesc = (FieldDescription)get(idPos+(i+1)*2);
1207             parameters[i] = fieldDesc.type;
1208             fieldNames[i] = fieldDesc.name;
1209         }
1210         return new ConstructorAst(annotations, ((Token)get(idPos)).text, parameters, fieldNames);
1211     }
1212
1213     @Override
1214     protected Object reduceFieldDescription() {
1215         return new FieldDescription(((Token)get(0)).text, (TypeAst)get(2));
1216     }
1217
1218     @Override
1219     protected Object reduceEq() {
1220         return (Expression)get(2);
1221     }
1222
1223     @Override
1224     protected Object reduceEquationBlock() {
1225         if(length() == 0)
1226             return new EEquations(Equation.EMPTY_ARRAY);
1227         Equation[] equations = new Equation[length()/2+1];
1228         for(int i=0;i<equations.length;++i)
1229             equations[i] = (Equation)get(2*i);
1230         return new EEquations(equations);
1231     }
1232
1233     @Override
1234     protected Object reduceGuardEquation() {
1235         return new EqGuard((Expression)get(0));
1236     }
1237
1238     @Override
1239     protected Object reduceBasicEquation() {
1240         return new EqBasic((Expression)get(0), (Expression)get(2));
1241     }
1242
1243     @Override
1244     protected Object reduceViewPattern() {
1245         return new EViewPattern((Expression)get(1), (Expression)get(3));
1246     }
1247
1248     @Override
1249     protected Object reduceCHRStatement() {
1250         return new CHRStatement((ListQualifier[])get(0), (ListQualifier[])get(2));
1251     }
1252
1253     @Override
1254     protected Object reduceConstraintStatement() {
1255         TypeAst[] parameterTypes = new TypeAst[length()-2];
1256         for(int i=0;i<parameterTypes.length;++i)
1257             parameterTypes[i] = (TypeAst)get(2+i);
1258         return new ConstraintStatement((Token)get(1), parameterTypes);
1259     }
1260
1261     @Override
1262     protected Object reduceCHRQuery() {
1263         ListQualifier[] query = new ListQualifier[(length()+1)/2];
1264         for(int i=0;i<query.length;++i)
1265             query[i] = (ListQualifier)get(i*2);
1266         return query;
1267     }
1268
1269     /*
1270     @Override
1271     protected Object reduceWhen() {
1272         return new EWhen(
1273                 new QConjunction((Query[])get(1)),
1274                 (Expression)get(3));
1275     }*/
1276
1277     @Override
1278     protected Object reduceVerboseCHRQuery() {
1279         ListQualifier[] query = new ListQualifier[(length()-1)/2];
1280         for(int i=0;i<query.length;++i)
1281             query[i] = (ListQualifier)get(i*2+1);
1282         return query;
1283     }
1284
1285     @Override
1286     protected Object reduceVerboseCHRStatement() {
1287         return new CHRStatement((ListQualifier[])get(1), (ListQualifier[])get(3));
1288     }
1289
1290     @Override
1291     protected Object reduceDummy() {
1292         throw new UnsupportedOperationException();
1293     }
1294
1295 }