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.compilation.CompilationContext;
  12 import org.simantics.scl.compiler.constants.CharacterConstant;
  13 import org.simantics.scl.compiler.constants.StringConstant;
  14 import org.simantics.scl.compiler.elaboration.chr.ast.CHRAstAtom;
  15 import org.simantics.scl.compiler.elaboration.chr.ast.CHRAstBinds;
  16 import org.simantics.scl.compiler.elaboration.chr.ast.CHRAstConjunction;
  17 import org.simantics.scl.compiler.elaboration.chr.ast.CHRAstEquals;
  18 import org.simantics.scl.compiler.elaboration.chr.ast.CHRAstQuery;
  19 import org.simantics.scl.compiler.elaboration.equation.EqBasic;
  20 import org.simantics.scl.compiler.elaboration.equation.EqGuard;
  21 import org.simantics.scl.compiler.elaboration.equation.Equation;
  22 import org.simantics.scl.compiler.elaboration.expressions.Case;
  23 import org.simantics.scl.compiler.elaboration.expressions.EApply;
  24 import org.simantics.scl.compiler.elaboration.expressions.EAsPattern;
  25 import org.simantics.scl.compiler.elaboration.expressions.EBinary;
  26 import org.simantics.scl.compiler.elaboration.expressions.EBinaryRightSide;
  27 import org.simantics.scl.compiler.elaboration.expressions.EBlock;
  28 import org.simantics.scl.compiler.elaboration.expressions.EConstant;
  29 import org.simantics.scl.compiler.elaboration.expressions.EEnforce;
  30 import org.simantics.scl.compiler.elaboration.expressions.EEquations;
  31 import org.simantics.scl.compiler.elaboration.expressions.EFieldAccess;
  32 import org.simantics.scl.compiler.elaboration.expressions.EIf;
  33 import org.simantics.scl.compiler.elaboration.expressions.EIntegerLiteral;
  34 import org.simantics.scl.compiler.elaboration.expressions.ELambda;
  35 import org.simantics.scl.compiler.elaboration.expressions.EListComprehension;
  36 import org.simantics.scl.compiler.elaboration.expressions.EListLiteral;
  37 import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
  38 import org.simantics.scl.compiler.elaboration.expressions.EMatch;
  39 import org.simantics.scl.compiler.elaboration.expressions.EPreCHRSelect;
  40 import org.simantics.scl.compiler.elaboration.expressions.ERange;
  41 import org.simantics.scl.compiler.elaboration.expressions.ERealLiteral;
  42 import org.simantics.scl.compiler.elaboration.expressions.ERecord;
  43 import org.simantics.scl.compiler.elaboration.expressions.ESelect;
  44 import org.simantics.scl.compiler.elaboration.expressions.ESimpleLambda;
  45 import org.simantics.scl.compiler.elaboration.expressions.EStringLiteral;
  46 import org.simantics.scl.compiler.elaboration.expressions.ETransformation;
  47 import org.simantics.scl.compiler.elaboration.expressions.ETypeAnnotation;
  48 import org.simantics.scl.compiler.elaboration.expressions.EVar;
  49 import org.simantics.scl.compiler.elaboration.expressions.EVariable;
  50 import org.simantics.scl.compiler.elaboration.expressions.EViewPattern;
  51 import org.simantics.scl.compiler.elaboration.expressions.Expression;
  52 import org.simantics.scl.compiler.elaboration.expressions.GuardedExpression;
  53 import org.simantics.scl.compiler.elaboration.expressions.GuardedExpressionGroup;
  54 import org.simantics.scl.compiler.elaboration.expressions.Variable;
  55 import org.simantics.scl.compiler.elaboration.expressions.accessor.ExpressionAccessor;
  56 import org.simantics.scl.compiler.elaboration.expressions.accessor.FieldAccessor;
  57 import org.simantics.scl.compiler.elaboration.expressions.accessor.IdAccessor;
  58 import org.simantics.scl.compiler.elaboration.expressions.accessor.StringAccessor;
  59 import org.simantics.scl.compiler.elaboration.expressions.block.BindStatement;
  60 import org.simantics.scl.compiler.elaboration.expressions.block.BlockType;
  61 import org.simantics.scl.compiler.elaboration.expressions.block.CHRStatement;
  62 import org.simantics.scl.compiler.elaboration.expressions.block.ConstraintStatement;
  63 import org.simantics.scl.compiler.elaboration.expressions.block.GuardStatement;
  64 import org.simantics.scl.compiler.elaboration.expressions.block.IncludeStatement;
  65 import org.simantics.scl.compiler.elaboration.expressions.block.LetStatement;
  66 import org.simantics.scl.compiler.elaboration.expressions.block.RuleStatement;
  67 import org.simantics.scl.compiler.elaboration.expressions.block.Statement;
  68 import org.simantics.scl.compiler.elaboration.expressions.list.ListAssignment;
  69 import org.simantics.scl.compiler.elaboration.expressions.list.ListGenerator;
  70 import org.simantics.scl.compiler.elaboration.expressions.list.ListGuard;
  71 import org.simantics.scl.compiler.elaboration.expressions.list.ListQualifier;
  72 import org.simantics.scl.compiler.elaboration.expressions.list.ListSeq;
  73 import org.simantics.scl.compiler.elaboration.expressions.list.ListThen;
  74 import org.simantics.scl.compiler.elaboration.expressions.records.FieldAssignment;
  75 import org.simantics.scl.compiler.elaboration.java.Builtins;
  76 import org.simantics.scl.compiler.elaboration.query.QAlternative;
  77 import org.simantics.scl.compiler.elaboration.query.QConjunction;
  78 import org.simantics.scl.compiler.elaboration.query.QDisjunction;
  79 import org.simantics.scl.compiler.elaboration.query.QNegation;
  80 import org.simantics.scl.compiler.elaboration.query.Query;
  81 import org.simantics.scl.compiler.elaboration.query.pre.QPreBinds;
  82 import org.simantics.scl.compiler.elaboration.query.pre.QPreEquals;
  83 import org.simantics.scl.compiler.elaboration.query.pre.QPreGuard;
  84 import org.simantics.scl.compiler.errors.Locations;
  85 import org.simantics.scl.compiler.internal.header.ModuleHeader;
  86 import org.simantics.scl.compiler.internal.parsing.Symbol;
  87 import org.simantics.scl.compiler.internal.parsing.Token;
  88 import org.simantics.scl.compiler.internal.parsing.declarations.ConstructorAst;
  89 import org.simantics.scl.compiler.internal.parsing.declarations.DAnnotationAst;
  90 import org.simantics.scl.compiler.internal.parsing.declarations.DClassAst;
  91 import org.simantics.scl.compiler.internal.parsing.declarations.DDataAst;
  92 import org.simantics.scl.compiler.internal.parsing.declarations.DDerivingInstanceAst;
  93 import org.simantics.scl.compiler.internal.parsing.declarations.DDocumentationAst;
  94 import org.simantics.scl.compiler.internal.parsing.declarations.DEffectAst;
  95 import org.simantics.scl.compiler.internal.parsing.declarations.DFixityAst;
  96 import org.simantics.scl.compiler.internal.parsing.declarations.DImportJavaAst;
  97 import org.simantics.scl.compiler.internal.parsing.declarations.DInstanceAst;
  98 import org.simantics.scl.compiler.internal.parsing.declarations.DMappingRelationAst;
  99 import org.simantics.scl.compiler.internal.parsing.declarations.DRelationAst;
 100 import org.simantics.scl.compiler.internal.parsing.declarations.DRuleAst;
 101 import org.simantics.scl.compiler.internal.parsing.declarations.DRulesetAst;
 102 import org.simantics.scl.compiler.internal.parsing.declarations.DTypeAst;
 103 import org.simantics.scl.compiler.internal.parsing.declarations.DValueAst;
 104 import org.simantics.scl.compiler.internal.parsing.declarations.DValueTypeAst;
 105 import org.simantics.scl.compiler.internal.parsing.declarations.DeclarationAst;
 106 import org.simantics.scl.compiler.internal.parsing.declarations.FieldDescription;
 107 import org.simantics.scl.compiler.internal.parsing.declarations.FundepAst;
 108 import org.simantics.scl.compiler.internal.parsing.exceptions.SCLSyntaxErrorException;
 109 import org.simantics.scl.compiler.internal.parsing.types.TApplyAst;
 110 import org.simantics.scl.compiler.internal.parsing.types.TEffectAst;
 111 import org.simantics.scl.compiler.internal.parsing.types.TForAllAst;
 112 import org.simantics.scl.compiler.internal.parsing.types.TFunctionAst;
 113 import org.simantics.scl.compiler.internal.parsing.types.TListAst;
 114 import org.simantics.scl.compiler.internal.parsing.types.TPredAst;
 115 import org.simantics.scl.compiler.internal.parsing.types.TTupleAst;
 116 import org.simantics.scl.compiler.internal.parsing.types.TVarAst;
 117 import org.simantics.scl.compiler.internal.parsing.types.TypeAst;
 118 import org.simantics.scl.compiler.module.ImportDeclaration;
 119 import org.simantics.scl.compiler.types.Types;
 120
 121
 122 public class SCLParserImpl extends SCLParser {
 123
 124     private final SCLPostLexer lexer;
 125     private SCLParserOptions options;
 126     private CompilationContext context;
 127
 128     public SCLParserImpl(Reader reader) {
 129         this.lexer = new SCLPostLexer(reader);
 130     }
 131
 132     public void setCompilationContext(CompilationContext context) {
 133         this.context = context;
 134         lexer.setCompilationContext(context);
 135     }
 136
 137     public void setParserOptions(SCLParserOptions options) {
 138         this.options = options;
 139         lexer.setParserOptions(options);
 140     }
 141
 142     public boolean isEmpty() throws Exception {
 143         return lexer.peekToken().id == SCLTerminals.EOF;
 144     }
 145
 146     @Override
 147     protected Token nextToken() {
 148         try {
 149             Token token = lexer.nextToken();
 150             /*System.out.println("TOKEN " + token.text + " (" + TERMINAL_NAMES[token.id] + ")" +
 151                     " ["
 152                     + Locations.beginOf(token.location) + ".."
 153                     + Locations.endOf(token.location) + "]");*/
 154             return token;
 155         } catch(Exception e) {
 156             if(e instanceof RuntimeException)
 157                 throw (RuntimeException)e;
 158             else
 159                 throw new RuntimeException(e);
 160         }
 161     }
 162
 163     @Override
 164     protected Object reduceDeclarations() {
 165         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2);
 166         for(int i=1;i<length();i+=2)
 167             declarations.add((DeclarationAst)get(i));
 168         return declarations;
 169     }
 170
 171     @Override
 172     protected Object reduceModule() {
 173         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2+1);
 174         for(int i=0;i<length();i+=2) {
 175             DeclarationAst declaration = (DeclarationAst)get(i);
 176             if(declaration == null)
 177                 continue;
 178             declarations.add(declaration);
 179         }
 180         return declarations;
 181     }
 182
 183     @Override
 184     protected Object reduceModuleHeader() {
 185         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
 186         for(int i=0;i<fields.length;++i)
 187             fields[i] = (FieldAssignment)get(2+i*2);
 188         context.header = ModuleHeader.process(context.errorLog, fields);
 189         return null;
 190     }
 191
 192     @Override
 193     protected Object reduceLocalTypeAnnotation() {
 194         if(length() == 1)
 195             return get(0);
 196         return new ETypeAnnotation((Expression)get(0), (TypeAst)get(2));
 197     }
 198
 199     @Override
 200     protected Object reduceTypeAnnotation() {
 201         EVar[] names = new EVar[length()/2];
 202         for(int i=0;i<names.length;++i)
 203             names[i] = (EVar)get(i*2);
 204         return new DValueTypeAst(
 205                 names,
 206                 (TypeAst)get(length()-1)
 207                 );
 208     }
 209
 210     @Override
 211     protected Object reduceValueDefinition() {
 212         Expression rhs = (Expression)get(1);
 213         return new DValueAst((Expression)get(0), rhs);
 214     }
 215
 216     @Override
 217     protected Object reduceDataDefinition() {
 218         int i=2;
 219         ArrayList<String> parameters = new ArrayList<String>();
 220         while(i < length()) {
 221             Token token = (Token)get(i++);
 222             if(token.id != SCLTerminals.ID)
 223                 break;
 224             parameters.add(token.text);
 225         }
 226         ArrayList<ConstructorAst> constructors = new ArrayList<ConstructorAst>();
 227         for(;i < length();i+=2)
 228             constructors.add((ConstructorAst)get(i));
 229         return new DDataAst(
 230                 ((Token)get(1)).text,
 231                 parameters.toArray(new String[parameters.size()]),
 232                 constructors.toArray(new ConstructorAst[constructors.size()]),
 233                 new String[0]
 234                 );
 235     }
 236
 237     @Override
 238     protected Object reduceTypeDefinition() {
 239         int i=2;
 240         ArrayList<String> parameters = new ArrayList<String>();
 241         while(true) {
 242             Token token = (Token)get(i++);
 243             if(token.id != SCLTerminals.ID)
 244                 break;
 245             parameters.add(token.text);
 246         }
 247         return new DTypeAst(
 248                 ((Token)get(1)).text,
 249                 parameters.toArray(new String[parameters.size()]),
 250                 (TypeAst)get(i)
 251                 );
 252     }
 253
 254     @SuppressWarnings("unchecked")
 255     @Override
 256     protected Object reduceClassDefinition() {
 257         int i=1;
 258         ArrayList<TypeAst> context;
 259         if(get(i) instanceof Token)
 260             context = new ArrayList<TypeAst>(0);
 261         else
 262             context = (ArrayList<TypeAst>)get(i++);
 263         String name = ((Token)get(i++)).text;
 264         ArrayList<String> parameters = new ArrayList<String>();
 265         while(i < length()) {
 266             Token token = (Token)get(i);
 267             if(token.id != SCLTerminals.ID)
 268                 break;
 269             parameters.add(token.text);
 270             ++i;
 271         }
 272         ArrayList<DeclarationAst> declarations = null;
 273         FundepAst[] fundeps = FundepAst.EMPTY_ARRAY;
 274         while(i < length()) {
 275             Token token = (Token)get(i++);
 276             if(token.id == SCLTerminals.WHERE) {
 277                 declarations = (ArrayList<DeclarationAst>)get(i++);
 278             }
 279             else if(token.id == SCLTerminals.BAR) {
 280                 fundeps = (FundepAst[])get(i++);
 281             }
 282             else
 283                 throw new InternalCompilerError();
 284         }
 285         return new DClassAst(context, name,
 286                 parameters.toArray(new String[parameters.size()]),
 287                 fundeps,
 288                 declarations);
 289     }
 290
 291     @Override
 292     protected Object reduceFundep() {
 293         String[] from = new String[length()-2];
 294         for(int i=0;i<from.length;++i)
 295             from[i] = ((Token)get(i)).text;
 296         String to = ((Token)get(length()-1)).text;
 297         return new FundepAst(from, to);
 298     }
 299
 300     @Override
 301     protected Object reduceFundeps() {
 302         FundepAst[] fundeps = new FundepAst[(length()+1)/2];
 303         for(int i=0;i<fundeps.length;++i)
 304             fundeps[i] = (FundepAst)get(i*2);
 305         return fundeps;
 306     }
 307
 308     @SuppressWarnings("unchecked")
 309     @Override
 310     protected Object reduceInstanceDefinition() {
 311         int i=1;
 312         ArrayList<TypeAst> context;
 313         if(get(i) instanceof Token)
 314             context = new ArrayList<TypeAst>(0);
 315         else
 316             context = (ArrayList<TypeAst>)get(i++);
 317         Token nameToken = (Token)get(i++);
 318         EVar name = new EVar(nameToken);
 319         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 320         while(i < length()) {
 321             Object symbol = get(i++);
 322             if(symbol instanceof Token)
 323                 break;
 324             parameters.add((TypeAst)symbol);
 325         }
 326         ArrayList<DeclarationAst> declarations = null;
 327         if(i < length())
 328             declarations = (ArrayList<DeclarationAst>)get(i);
 329         return new DInstanceAst(context, name,
 330                 parameters.toArray(new TypeAst[parameters.size()]),
 331                 declarations);
 332     }
 333
 334     @SuppressWarnings("unchecked")
 335     @Override
 336     protected Object reduceDerivingInstanceDefinition() {
 337         int i=2;
 338         ArrayList<TypeAst> context;
 339         if(get(i) instanceof Token)
 340             context = new ArrayList<TypeAst>(0);
 341         else
 342             context = (ArrayList<TypeAst>)get(i++);
 343         Token nameToken = (Token)get(i++);
 344         EVar name = new EVar(nameToken);
 345         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 346         while(i < length()) {
 347             Object symbol = get(i++);
 348             parameters.add((TypeAst)symbol);
 349         }
 350         return new DDerivingInstanceAst(context, name,
 351                 parameters.toArray(new TypeAst[parameters.size()]));
 352     }
 353
 354     @Override
 355     protected Object reduceDocumentationString() {
 356         return new DDocumentationAst(((Token)get(1)).text);
 357     }
 358
 359     @Override
 360     protected Object reduceAnnotation() {
 361         ArrayList<Expression> parameters = new ArrayList<Expression>(length()-1);
 362         for(int i=1;i<length();++i)
 363             parameters.add((Expression)get(i));
 364         return new DAnnotationAst((Token)get(0), parameters);
 365     }
 366
 367     @Override
 368     protected Object reducePrecedenceDefinition() {
 369         EVar[] symbols = new EVar[length()/2];
 370         for(int i=0;i<symbols.length;++i)
 371             symbols[i] = (EVar)get(2*i + 2);
 372         Associativity associativity;
 373         Token token = (Token)get(0);
 374         if(token.text.equals("infixl"))
 375             associativity = Associativity.LEFT;
 376         else if(token.text.equals("infixr"))
 377             associativity = Associativity.RIGHT;
 378         else
 379             associativity = Associativity.NONASSOC;
 380         return new DFixityAst(
 381                 new Precedence(
 382                         Integer.parseInt(((Token)get(1)).text),
 383                         associativity),
 384                         symbols);
 385     }
 386
 387     @Override
 388     protected Object reduceImport() {
 389         // (AS ID)? importSpec?
 390         int pos = 0;
 391         String importKeyword = ((Token)get(pos++)).text; // (IMPORT | INCLUDE)
 392         ++pos; // BEGIN_STRING
 393         String moduleName = ((Token)get(pos++)).text; // END_STRING
 394         String localName = "";
 395         if(pos < length()) {
 396             Object temp = get(pos);
 397             if(temp instanceof Token) {
 398                 Token token = (Token)temp;
 399                 if(token.id == SCLTerminals.AS) {
 400                     ++pos; // AS
 401                     localName = ((Token)get(pos++)).text; // ID
 402                 }
 403             }
 404         }
 405         ImportDeclaration.ImportSpec spec = ImportDeclaration.DEFAULT_SPEC;
 406         if(pos < length())
 407             spec = (ImportDeclaration.ImportSpec)get(pos++);
 408         return new ImportDeclaration(moduleName, localName,
 409                         importKeyword.equals("include"),
 410                         spec);
 411     }
 412
 413     @Override
 414     protected Object reduceJustImport() {
 415         return get(0);
 416     }
 417
 418     @SuppressWarnings("unchecked")
 419     @Override
 420     protected Object reduceImportJava() {
 421         return new DImportJavaAst(((Token)get(2)).text, (ArrayList<DeclarationAst>)get(4));
 422     }
 423
 424     @Override
 425     protected Object reduceEffectDefinition() {
 426         return new DEffectAst(
 427                 ((Token)get(1)).text,
 428                 ((Token)get(3)).text,
 429                 ((Token)get(5)).text);
 430     }
 431
 432     @Override
 433     protected Object reduceVarId() {
 434         return new EVar((Token)get(0));
 435     }
 436
 437     @Override
 438     protected Object reduceEscapedSymbol() {
 439         return new EVar((Token)get(0));
 440     }
 441
 442     @Override
 443     protected Object reduceTupleTypeConstructor() {
 444         return new TVarAst(Types.tupleConstructor(length()-1).name);
 445     }
 446
 447     @Override
 448     protected Object reduceArrow() {
 449         int i=length()-1;
 450         TypeAst result = (TypeAst)get(i);
 451         i-=2;
 452         while(i >= 0) {
 453             if( ((Token)get(i+1)).text.equals("=>") )
 454                 result = new TPredAst((TypeAst)get(i), result);
 455             else
 456                 result = new TFunctionAst((TypeAst)get(i), result);
 457             i-=2;
 458         }
 459         return result;
 460     }
 461
 462     @Override
 463     protected Object reduceBinary() {
 464         if(length() == 1)
 465             return get(0);
 466         int i=0;
 467         EVar negation = null;
 468         if(get(i) instanceof Token) {
 469             Token token = (Token)get(i++);
 470             negation = new EVar(token);
 471         }
 472         EBinary binary = new EBinary((Expression)get(i++), negation);
 473         while(i < length()) {
 474             EVar operator = (EVar)get(i++);
 475             Expression right = (Expression)get(i++);
 476             binary.rights.add(new EBinaryRightSide(operator, right));
 477         }
 478         return binary;
 479     }
 480
 481     @Override
 482     protected Object reduceSimpleRhs() {
 483         if(length() == 2)
 484             return get(1);
 485         else {
 486             EBlock block = (EBlock)get(3);
 487             Expression expression = (Expression)get(1);
 488             block.addStatement(new GuardStatement(expression));
 489             block.location = Locations.location(Locations.beginOf(expression.location), Locations.endOf(block.location));
 490             return block;
 491         }
 492     }
 493
 494     private GuardedExpressionGroup reduceGuardedExpressionGroup(int length) {
 495         GuardedExpression[] expressions = new GuardedExpression[length];
 496         for(int i=0;i<expressions.length;++i) {
 497             expressions[i] = (GuardedExpression)get(i);
 498         }
 499         return new GuardedExpressionGroup(expressions);
 500     }
 501
 502     @Override
 503     protected Object reduceGuardedRhs() {
 504         int length = length();
 505         if(length > 2 && get(length-2) instanceof Token) {
 506             EBlock block = (EBlock)get(length-1);
 507             block.addStatement(new GuardStatement(reduceGuardedExpressionGroup(length-2)));
 508             block.location = Locations.NO_LOCATION;
 509             return block;
 510         }
 511         else
 512             return reduceGuardedExpressionGroup(length);
 513     }
 514
 515     @Override
 516     protected Object reduceStatements() {
 517         EBlock block = new EBlock();
 518         if(length() > 2)
 519             for(int i=1;i<length();i+=2)
 520                 block.addStatement((Statement)get(i));
 521         return block;
 522     }
 523
 524     @Override
 525     protected Object reduceConstructor() {
 526         int idPos;
 527         for(idPos=0;idPos<length();idPos+=2)
 528             if(((Token)get(idPos)).id == SCLTerminals.ID)
 529                 break;
 530         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
 531         for(int i=0;i<idPos/2;++i)
 532             annotations[i] = new DAnnotationAst((Token)get(i*2),
 533                     Arrays.asList((Expression)get(i*2+1)));
 534         TypeAst[] parameters = new TypeAst[length()-idPos-1];
 535         for(int i=0;i<parameters.length;++i)
 536             parameters[i] = (TypeAst)get(i+idPos+1);
 537         return new ConstructorAst(annotations, (Token)get(idPos), parameters, null);
 538     }
 539
 540     @Override
 541     protected Object reduceContext() {
 542         ArrayList<TypeAst> result = new ArrayList<TypeAst>(length()/2-1);
 543         for(int i=1;i<length()-2;i+=2)
 544             result.add((TypeAst)get(i));
 545         return result;
 546     }
 547
 548     @Override
 549     protected Object reduceTypeVar() {
 550         return new TVarAst(((Token)get(0)).text);
 551     }
 552
 553     @Override
 554     protected Object reduceTupleType() {
 555         if(length() == 2)
 556             return new TTupleAst(TypeAst.EMPTY_ARRAY);
 557         if(length() == 3) {
 558             Symbol sym = (Symbol)get(1);
 559             sym.location = Locations.NO_LOCATION;
 560             return sym;
 561         }
 562         int dim = length()/2;
 563         TypeAst[] parameters = new TypeAst[dim];
 564         for(int i=0;i<dim;++i)
 565             parameters[i] = (TypeAst)get(i*2+1);
 566         return new TTupleAst(parameters);
 567     }
 568
 569     @Override
 570     protected Object reduceListType() {
 571         return new TListAst((TypeAst)get(1));
 572     }
 573
 574     @Override
 575     protected Object reduceListTypeConstructor() {
 576         return new TVarAst("[]");
 577     }
 578
 579     @Override
 580     protected Object reduceTupleConstructor() {
 581         return new EVar(Types.tupleConstructor(length()-1).name);
 582     }
 583
 584     @Override
 585     protected Object reduceVar() {
 586         return get(0);
 587     }
 588
 589     @Override
 590     protected Object reduceBlank() {
 591         return new EVar(((Token)get(0)).location, "_");
 592     }
 593
 594     @Override
 595     protected Object reduceInteger() {
 596         return new EIntegerLiteral(((Token)get(0)).text);
 597     }
 598
 599     @Override
 600     protected Object reduceFloat() {
 601         return new ERealLiteral(((Token)get(0)).text);
 602     }
 603
 604     @Override
 605     protected Object reduceString() {
 606         return get(0);
 607     }
 608
 609     @Override
 610     protected Object reduceChar() {
 611         String text = ((Token)get(0)).text;
 612         char c = text.charAt(text.length()-2);
 613         if(text.length() == 4) {
 614             switch(c) {
 615             case 'n': c = '\n'; break;
 616             case 't': c = '\t'; break;
 617             case 'b': c = '\b'; break;
 618             case 'f': c = '\f'; break;
 619             case 'r': c = '\r'; break;
 620             }
 621         }
 622         return new ELiteral(new CharacterConstant(c));
 623     }
 624
 625     @Override
 626     protected Object reduceTuple() {
 627         if(length() == 2)
 628             return new EConstant(Builtins.TUPLE_CONSTRUCTORS[0]);
 629         if(length() == 3) {
 630             Symbol sym = (Symbol)get(1);
 631             sym.location = Locations.NO_LOCATION;
 632             return sym;
 633         }
 634         int dim = length()/2;
 635         Expression[] parameters = new Expression[dim];
 636         for(int i=0;i<dim;++i)
 637             parameters[i] = (Expression)get(i*2+1);
 638         EConstant tupleConstructor = new EConstant(Builtins.TUPLE_CONSTRUCTORS[dim]);
 639         tupleConstructor.location = Locations.location(
 640                 Locations.beginOf(((Token)get(0)).location),
 641                 Locations.endOf(((Token)get(length()-1)).location));
 642         return new EApply(tupleConstructor, parameters);
 643     }
 644
 645     public static Expression rightSection(EVar op, Expression e) {
 646         long loc = Locations.combine(op.location, e.location);
 647         Variable var = new Variable("rightSectionTemp");
 648         return new ESimpleLambda(loc, var,
 649                 new EApply(loc, op, new EVariable(loc, var), e));
 650     }
 651
 652     @Override
 653     protected Object reduceRightSection() {
 654         Variable var = new Variable("rightSectionTemp");
 655         long loc = Locations.combine(((Token)get(0)).location, ((Token)get(length()-1)).location);
 656         EVar symbol = (EVar)get(1);
 657         return new ESimpleLambda(var,
 658                 new EApply(loc, symbol,
 659                         new EVariable(loc, var), (Expression)get(2)));
 660     }
 661
 662     @Override
 663     protected Object reduceLeftSection() {
 664         return new EApply((EVar)get(2), (Expression)get(1));
 665     }
 666
 667     @Override
 668     protected Object reduceListLiteral() {
 669         if(length() == 2)
 670             return new EListLiteral(Expression.EMPTY_ARRAY);
 671         int dim = length()/2;
 672         Expression[] components = new Expression[dim];
 673         for(int i=0;i<dim;++i)
 674             components[i] = (Expression)get(i*2+1);
 675         return new EListLiteral(components);
 676     }
 677
 678     @Override
 679     protected Object reduceRange() {
 680         return new ERange(
 681                 (Expression)get(1),
 682                 (Expression)get(3)
 683                 );
 684     }
 685
 686     @Override
 687     protected Object reduceListComprehension() {
 688         ListQualifier qualifier = (ListQualifier)get(3);
 689         for(int i=5;i<length();i+=2) {
 690             ListQualifier right = (ListQualifier)get(i);
 691             if(right instanceof ListThen) {
 692                 ((ListThen) right).setLeft(qualifier);
 693                 qualifier = right;
 694             }
 695             else
 696                 qualifier = new ListSeq(qualifier, right);
 697         }
 698         return new EListComprehension((Expression)get(1), qualifier);
 699     }
 700
 701     @Override
 702     protected Object reduceAs() {
 703         Token id = (Token)get(0);
 704         return new EAsPattern(new EVar(id.location, id.text), (Expression)get(2));
 705     }
 706
 707     @Override
 708     protected Object reduceGuardedExpEq() {
 709         Expression[] guards = new Expression[length()/2-1];
 710         for(int i=0;i<guards.length;++i)
 711             guards[i] = (Expression)get(i*2+1);
 712         return new GuardedExpression(guards, (Expression)get(length()-1));
 713     }
 714
 715     @Override
 716     protected Object reduceLambda() {
 717         Expression[] patterns = new Expression[length()-3];
 718         for(int i=0;i<patterns.length;++i)
 719             patterns[i] = (Expression)get(i+1);
 720         Case case_ = new Case(patterns, (Expression)get(length()-1));
 721         case_.setLhs(Locations.combine(patterns[0].location, patterns[patterns.length-1].location));
 722         return new ELambda(case_);
 723     }
 724
 725     @Override
 726     protected Object reduceLambdaMatch() {
 727         Case[] cases = new Case[length()/2-1];
 728         for(int i=0;i<cases.length;++i)
 729             cases[i] = (Case)get(i*2+2);
 730         return new ELambda(cases);
 731     }
 732
 733     @Override
 734     protected Object reduceLet() {
 735         EBlock block = (EBlock)get(1);
 736         Expression expression = (Expression)get(3);
 737         block.addStatement(new GuardStatement(expression));
 738         Token letToken = (Token)get(0);
 739         block.location = Locations.location(
 740                 Locations.beginOf(letToken.location),
 741                 Locations.endOf(expression.location));
 742         return block;
 743     }
 744
 745     @Override
 746     protected Object reduceIf() {
 747         return new EIf(
 748                 (Expression)get(1),
 749                 (Expression)get(3),
 750                 length() == 6 ? (Expression)get(5) : null);
 751     }
 752
 753     @Override
 754     protected Object reduceMatch() {
 755         Case[] cases = new Case[length()/2-2];
 756         for(int i=0;i<cases.length;++i)
 757             cases[i] = (Case)get(i*2+4);
 758         return new EMatch((Expression)get(1), cases);
 759     }
 760
 761     @Override
 762     protected Object reduceDo() {
 763         EBlock block = (EBlock)get(1);
 764         Token doToken = (Token)get(0);
 765         switch(doToken.text) {
 766         case "mdo":
 767             block.setBlockType(BlockType.Monad);
 768             break;
 769         case "edo":
 770             block.setBlockType(BlockType.MonadE);
 771             break;
 772         }
 773         block.location = Locations.location(Locations.beginOf(doToken.location), Locations.endOf(block.location));
 774         return block;
 775     }
 776
 777     @Override
 778     protected Object reduceSelect() {
 779         return new ESelect(((Token)get(0)).id, (Expression)get(1), new QConjunction((Query[])get(3)));
 780     }
 781
 782     @Override
 783     protected Object reduceEnforce() {
 784         return new EEnforce(new QConjunction((Query[])get(1)));
 785     }
 786
 787     @Override
 788     protected Object reduceApply() {
 789         if(length() == 1)
 790             return get(0);
 791         Expression[] parameters = new Expression[length()-1];
 792         for(int i=0;i<parameters.length;++i)
 793             parameters[i] = (Expression)get(i+1);
 794         return new EApply((Expression)get(0), parameters);
 795     }
 796
 797     @Override
 798     protected Object reduceSymbol() {
 799         return new EVar(((Token)get(0)).text);
 800     }
 801
 802     @Override
 803     protected Object reduceEscapedId() {
 804         return new EVar(((Token)get(0)).text);
 805     }
 806
 807     @Override
 808     protected Object reduceMinus() {
 809         return new EVar(((Token)get(0)).text);
 810     }
 811
 812     @Override
 813     protected Object reduceLess() {
 814         return new EVar(((Token)get(0)).text);
 815     }
 816
 817     @Override
 818     protected Object reduceGreater() {
 819         return new EVar(((Token)get(0)).text);
 820     }
 821
 822     @Override
 823     protected Object reduceDot() {
 824         return new EVar(((Token)get(0)).text);
 825     }
 826
 827     @Override
 828     protected Object reduceCase() {
 829         return new Case((Expression)get(0), (Expression)get(1));
 830     }
 831
 832     @Override
 833     protected Object reduceGuardQualifier() {
 834         return new ListGuard((Expression)get(0));
 835     }
 836
 837     @Override
 838     protected Object reduceLetQualifier() {
 839         return new ListAssignment((Expression)get(0), (Expression)get(2));
 840     }
 841
 842     @Override
 843     protected Object reduceBindQualifier() {
 844         return new ListGenerator((Expression)get(0), (Expression)get(2));
 845     }
 846
 847     @Override
 848     protected Object reduceThenQualifier() {
 849         return new ListThen((Expression)get(1), length()==4 ? (Expression)get(3) : null);
 850     }
 851
 852     @Override
 853     protected Object reduceGuardStatement() {
 854         return new GuardStatement((Expression)get(0));
 855     }
 856
 857     @Override
 858     protected Object reduceLetStatement() {
 859         return new LetStatement((Expression)get(0), (Expression)get(1));
 860     }
 861
 862     @Override
 863     protected Object reduceBindStatement() {
 864         return new BindStatement((Expression)get(0), (Expression)get(2));
 865     }
 866
 867     @Override
 868     protected Object reduceSimpleCaseRhs() {
 869         return get(1);
 870     }
 871
 872     @Override
 873     protected Object reduceGuardedCaseRhs() {
 874         GuardedExpression[] expressions = new GuardedExpression[length()];
 875         for(int i=0;i<expressions.length;++i)
 876             expressions[i] = (GuardedExpression)get(i);
 877         return new GuardedExpressionGroup(expressions);
 878     }
 879
 880     @Override
 881     protected Object reduceGuardedExpArrow() {
 882         Expression[] guards = new Expression[length()/2-1];
 883         for(int i=0;i<guards.length;++i)
 884             guards[i] = (Expression)get(i*2+1);
 885         return new GuardedExpression(guards, (Expression)get(length()-1));
 886     }
 887
 888     @Override
 889     protected Object reduceEffect() {
 890         ArrayList<TypeAst> effects = new ArrayList<TypeAst>(length()/2-1);
 891         for(int i=1;i<length()-1;i+=2) {
 892             Token token = (Token)get(i);
 893             TVarAst ast = new TVarAst(token.text);
 894             ast.location = token.location;
 895             effects.add(ast);
 896         }
 897         return new TEffectAst(effects, (TypeAst)get(length()-1));
 898     }
 899
 900     @Override
 901     protected Object reduceJustEtype() {
 902         return get(0);
 903     }
 904
 905     @Override
 906     protected Object reduceForAll() {
 907         String[] vars = new String[length()-3];
 908         for(int i=0;i<vars.length;++i)
 909             vars[i] = ((Token)get(i+1)).text;
 910         return new TForAllAst(vars, (TypeAst)get(length()-1));
 911     }
 912
 913     @Override
 914     protected Object reduceApplyType() {
 915         TypeAst[] parameters = new TypeAst[length()-1];
 916         for(int i=0;i<parameters.length;++i)
 917             parameters[i] = (TypeAst)get(i+1);
 918         return new TApplyAst((TypeAst)get(0), parameters);
 919     }
 920
 921     @SuppressWarnings("unchecked")
 922     @Override
 923     protected void postReduce(Object reduced) {
 924         if(!(reduced instanceof Symbol))
 925             return;
 926         Symbol sym = (Symbol)reduced;
 927         if(sym.location != Locations.NO_LOCATION || length() == 0)
 928             return;
 929         Object first = get(0);
 930         if(!(first instanceof Symbol)) {
 931             if(first instanceof List) {
 932                 List<Object> ll = (List<Object>)first;
 933                 first = ll.get(0);
 934             }
 935             else {
 936                 Object[] ll = (Object[])first;
 937                 if(ll.length > 0)
 938                     first = ll[0];
 939                 else
 940                     first = get(1);
 941             }
 942         }
 943         Object last = get(length()-1);
 944         if(!(last instanceof Symbol)) {
 945             if(last instanceof List) {
 946                 List<Object> ll = (List<Object>)last;
 947                 last = ll.get(ll.size()-1);
 948             }
 949             else {
 950                 Object[] ll = (Object[])last;
 951                 if(ll.length > 0)
 952                     last = ll[ll.length-1];
 953                 else
 954                     last = get(length()-2);
 955             }
 956         }
 957         sym.location = (((Symbol)first).location & 0xffffffff00000000L)
 958                 | (((Symbol)last).location & 0xffffffffL);
 959         /*for(int i=0;i<length();++i) {
 960             Object obj = get(i);
 961             System.out.print(obj.getClass().getSimpleName());
 962             if(obj instanceof Token) {
 963                 Token t = (Token)obj;
 964                 System.out.print("(" + t.text + ")");
 965             }
 966             if(obj instanceof Symbol) {
 967                 Symbol s = (Symbol)obj;
 968                 System.out.print("["+ Locations.beginOf(s.location) + "-" + Locations.endOf(s.location) + "]");
 969             }
 970             System.out.print(" ");
 971         }
 972         System.out.println("-> " + reduced.getClass().getSimpleName() + " " +
 973                 Locations.beginOf(sym.location) + "-" + Locations.endOf(sym.location));*/
 974     }
 975
 976     @Override
 977     protected RuntimeException syntaxError(Token token, String description) {
 978         throw new SCLSyntaxErrorException(token.location, description);
 979     }
 980
 981     @Override
 982     protected Object reduceIdAccessor() {
 983         return new IdAccessor('.', ((Token)get(0)).text);
 984     }
 985
 986     @Override
 987     protected Object reduceStringAccessor() {
 988         return new StringAccessor('.', ((Token)get(1)).text);
 989     }
 990
 991     @Override
 992     protected Object reduceExpAccessor() {
 993         return new ExpressionAccessor('.', (Expression)get(1));
 994     }
 995
 996     @Override
 997     protected Object reduceFieldAccess() {
 998         if(length() == 1)
 999             return get(0);
1000         Expression result = (Expression)get(0);
1001         for(int i=2;i<length();i+=2) {
1002             FieldAccessor accessor = (FieldAccessor)get(i);
1003             accessor.accessSeparator = ((Token)get(i-1)).text.charAt(0);
1004             result = new EFieldAccess(result, accessor);
1005         }
1006         return result;
1007     }
1008
1009     @Override
1010     protected Object reduceQueryBlock() {
1011         if(length() == 2)
1012             return Query.EMPTY_ARRAY;
1013         Query[] queries = new Query[length()/2];
1014         for(int i=0;i<queries.length;++i)
1015             queries[i] = (Query)get(2*i+1);
1016         return queries;
1017     }
1018
1019     @Override
1020     protected Object reduceGuardQuery() {
1021         return new QPreGuard((Expression)get(0));
1022     }
1023
1024     @Override
1025     protected Object reduceEqualsQuery() {
1026         return new QPreEquals((Expression)get(0), (Expression)get(2));
1027     }
1028
1029     @Override
1030     protected Object reduceBindQuery() {
1031         return new QPreBinds((Expression)get(0), (Expression)get(2));
1032     }
1033
1034     @Override
1035     protected Object reduceCompositeQuery() {
1036         Query[] queries = (Query[])get(1);
1037         switch(((Token)get(0)).text.charAt(1)) {
1038         case '&': return new QConjunction(queries);
1039         case '|': return new QDisjunction(queries);
1040         case '!': return new QNegation(new QConjunction(queries));
1041         case '?': return new QAlternative(queries);
1042         default: throw new InternalCompilerError();
1043         }
1044     }
1045
1046     @Override
1047     protected Object reduceRuleStatement() {
1048         return new RuleStatement((Expression)get(0), new QConjunction((Query[])get(2)));
1049     }
1050
1051     @Override
1052     protected Object reduceHashedId() {
1053         return new EVar("#" + ((Token)get(1)).text);
1054     }
1055
1056     @Override
1057     protected Object reduceStringLiteral() {
1058         int expCount = length()/3;
1059         if(expCount == 0)
1060             return new ELiteral(new StringConstant(((Token)get(1)).text));
1061         else {
1062             String[] strings = new String[expCount+1];
1063             Expression[] expressions = new Expression[expCount];
1064             for(int i=0;i<expCount;++i) {
1065                 strings[i] = ((Token)get(i*3+1)).text;
1066                 expressions[i] = (Expression)get(i*3+2);
1067             }
1068             strings[expCount] = ((Token)get(expCount*3+1)).text;
1069             return new EStringLiteral(strings, expressions);
1070         }
1071     }
1072
1073     @Override
1074     protected Object reduceOneCommand() {
1075         return null;
1076     }
1077
1078     @Override
1079     protected Object reduceManyCommands() {
1080         return null;
1081     }
1082
1083     @Override
1084     protected Object reduceStatementCommand() {
1085         // to be extended in subclasses
1086         return null;
1087     }
1088
1089     @Override
1090     protected Object reduceImportCommand() {
1091         // to be extended in subclasses
1092         return null;
1093     }
1094
1095     @Override
1096     protected Object reduceImportValueItem() {
1097         return new EVar(((Token)get(0)).text);
1098     }
1099
1100     @Override
1101     protected Object reduceImportHiding() {
1102         EVar[] values = new EVar[(length()-2)/2];
1103         for(int i=0;i<values.length;++i)
1104             values[i] = (EVar)get(i*2+2);
1105         return new ImportDeclaration.ImportSpec(true, values);
1106     }
1107
1108     @Override
1109     protected Object reduceImportShowing() {
1110         EVar[] values = new EVar[(length()-1)/2];
1111         for(int i=0;i<values.length;++i)
1112             values[i] = (EVar)get(i*2+1);
1113         return new ImportDeclaration.ImportSpec(false, values);
1114     }
1115
1116     @Override
1117     protected Object reduceRuleDeclarations() {
1118         ArrayList<Object> declarations = new ArrayList<Object>(length()/2);
1119         for(int i=1;i<length();i+=2)
1120             declarations.add((Object)get(i));
1121         return declarations;
1122     }
1123
1124     private static final String[] EMPTY_STRING_ARRAY = new String[0];
1125
1126     @SuppressWarnings("unchecked")
1127     @Override
1128     protected Object reduceRuleDefinition() {
1129         String[] extendsNames = EMPTY_STRING_ARRAY;
1130         if(length() >= 6) {
1131             int extendsCount = (length() - 4) / 2;
1132             extendsNames = new String[extendsCount];
1133             for(int i=0;i<extendsCount;++i)
1134                 extendsNames[i] = ((Token)get(3+i*2)).text;
1135         }
1136
1137         DRuleAst rule = new DRuleAst(
1138                 ((Token)get(0)).id == SCLTerminals.ABSTRACT_RULE,
1139                 ((Token)get(1)).text,
1140                 extendsNames);
1141
1142         ArrayList<Object> ruleDeclarations = (ArrayList<Object>)get(length()-1);
1143         ArrayList<Query> section = null;
1144         for(Object decl : ruleDeclarations) {
1145             if(decl instanceof DAnnotationAst) {
1146                 DAnnotationAst annotation = (DAnnotationAst)decl;
1147                 section = rule.getSection(annotation.id.text.substring(1));
1148             }
1149             else if(decl instanceof Query) {
1150                 if(section == null)
1151                     section = rule.getSection("when");
1152                 section.add((Query)decl);
1153             }
1154             else
1155                 throw new InternalCompilerError();
1156         }
1157         return rule;
1158     }
1159
1160     @Override
1161     protected Object reduceQueryRuleDeclaration() {
1162         return get(0);
1163     }
1164
1165     @Override
1166     protected Object reduceMappingRelationDefinition() {
1167         TypeAst[] types = new TypeAst[length()-2];
1168         for(int i=0;i<types.length;++i)
1169             types[i] = (TypeAst)get(i+2);
1170         return new DMappingRelationAst(
1171                 ((Token)get(1)).text,
1172                 types);
1173     }
1174
1175     @Override
1176     protected Object reduceTransformation() {
1177         return new ETransformation(
1178                 ((Token)get(1)).text,
1179                 new QConjunction((Query[])get(3))
1180                 );
1181     }
1182
1183     @SuppressWarnings("unchecked")
1184     @Override
1185     protected Object reduceRelationDefinition() {
1186         return new DRelationAst((Expression)get(0),
1187                 ((ArrayList<Object>)get(2)).toArray());
1188     }
1189
1190     @Override
1191     protected Object reduceRecord() {
1192         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
1193         for(int i=0;i<fields.length;++i)
1194             fields[i] = (FieldAssignment)get(2+i*2);
1195         return new ERecord(new EVar((Token)get(0)), fields);
1196     }
1197
1198     @Override
1199     protected Object reduceField() {
1200         return new FieldAssignment(((Token)get(0)).text, (Expression)get(2));
1201     }
1202
1203     @Override
1204     protected Object reduceFieldShorthand() {
1205         return new FieldAssignment(((Token)get(0)).text, null);
1206     }
1207
1208     @Override
1209     protected Object reduceRecordConstructor() {
1210         int idPos;
1211         for(idPos=0;idPos<length();idPos+=2)
1212             if(((Token)get(idPos)).id == SCLTerminals.ID)
1213                 break;
1214         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
1215         for(int i=0;i<idPos/2;++i)
1216             annotations[i] = new DAnnotationAst((Token)get(i*2),
1217                     Arrays.asList((Expression)get(i*2+1)));
1218         TypeAst[] parameters = new TypeAst[(length()-idPos-1)/2];
1219         String[] fieldNames = new String[parameters.length];
1220         for(int i=0;i<parameters.length;++i) {
1221             FieldDescription fieldDesc = (FieldDescription)get(idPos+(i+1)*2);
1222             parameters[i] = fieldDesc.type;
1223             fieldNames[i] = fieldDesc.name;
1224         }
1225         return new ConstructorAst(annotations, (Token)get(idPos), parameters, fieldNames);
1226     }
1227
1228     @Override
1229     protected Object reduceFieldDescription() {
1230         return new FieldDescription(((Token)get(0)).text, (TypeAst)get(2));
1231     }
1232
1233     @Override
1234     protected Object reduceEq() {
1235         return (Expression)get(2);
1236     }
1237
1238     @Override
1239     protected Object reduceEquationBlock() {
1240         if(length() == 0)
1241             return new EEquations(Equation.EMPTY_ARRAY);
1242         Equation[] equations = new Equation[length()/2+1];
1243         for(int i=0;i<equations.length;++i)
1244             equations[i] = (Equation)get(2*i);
1245         return new EEquations(equations);
1246     }
1247
1248     @Override
1249     protected Object reduceGuardEquation() {
1250         return new EqGuard((Expression)get(0));
1251     }
1252
1253     @Override
1254     protected Object reduceBasicEquation() {
1255         return new EqBasic((Expression)get(0), (Expression)get(2));
1256     }
1257
1258     @Override
1259     protected Object reduceViewPattern() {
1260         return new EViewPattern((Expression)get(1), (Expression)get(3));
1261     }
1262
1263     @Override
1264     protected Object reduceConstraintStatement() {
1265         ConstructorAst constructor = (ConstructorAst)get(1);
1266         return new ConstraintStatement(constructor.name, constructor.parameters, constructor.fieldNames, constructor.annotations);
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 reduceDummy() {
1279         throw new UnsupportedOperationException();
1280     }
1281
1282     @Override
1283     protected Object reduceRulesetDefinition() {
1284         Token name = (Token)get(1);
1285         EBlock block = (EBlock)get(3);
1286         return new DRulesetAst(name.text, block);
1287     }
1288
1289     @Override
1290     protected Object reduceLocalInclude() {
1291         Token name = (Token)get(1);
1292         Expression value = (Expression)get(2);
1293         return new IncludeStatement(name, value);
1294     }
1295
1296     /*@Override
1297     protected Object reduceConstraintSpec() {
1298         Expression[] expressions = new Expression[length()/2-1];
1299         for(int i=0;i<expressions.length;++i)
1300             expressions[i] = (Expression)get(2*i+1);
1301         return expressions;
1302     }*/
1303
1304     @Override
1305     protected Object reduceCHRSelect() {
1306         return new EPreCHRSelect((CHRAstQuery)get(3), (Expression)get(1));
1307     }
1308
1309     @Override
1310     protected Object reduceCHRAtom() {
1311         return CHRAstAtom.atom((Expression)get(0));
1312     }
1313
1314     @Override
1315     protected Object reduceCHREquals() {
1316         return new CHRAstEquals((Expression)get(0), (Expression)get(2));
1317     }
1318
1319     @Override
1320     protected Object reduceCHRBinds() {
1321         return new CHRAstBinds((Expression)get(0), (Expression)get(2));
1322     }
1323
1324     @Override
1325     protected Object reduceCHRConjunction() {
1326         CHRAstQuery[] conjuncts = new CHRAstQuery[(length()+1)/2];
1327         for(int i=0;i<conjuncts.length;++i)
1328             conjuncts[i] = (CHRAstQuery)get(i*2);
1329         return CHRAstConjunction.conjunction(conjuncts);
1330     }
1331
1332     @Override
1333     protected Object reduceVerboseCHRConjunction() {
1334         CHRAstQuery[] conjuncts = new CHRAstQuery[(length()-1)/2];
1335         for(int i=0;i<conjuncts.length;++i)
1336             conjuncts[i] = (CHRAstQuery)get(i*2+1);
1337         return CHRAstConjunction.conjunction(conjuncts);
1338     }
1339
1340     @Override
1341     protected Object reduceVerboseCHRStatement() {
1342         return new CHRStatement((CHRAstQuery)get(1), (CHRAstQuery)get(3));
1343     }
1344
1345     @Override
1346     protected Object reduceCHRStatement() {
1347         return new CHRStatement((CHRAstQuery)get(0), (CHRAstQuery)get(2));
1348     }
1349
1350     @Override
1351     protected Object reduceWildcard() {
1352         return new FieldAssignment(FieldAssignment.WILDCARD, null);
1353     }
1354
1355 }