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.CHRStatement;
  61 import org.simantics.scl.compiler.elaboration.expressions.block.ConstraintStatement;
  62 import org.simantics.scl.compiler.elaboration.expressions.block.GuardStatement;
  63 import org.simantics.scl.compiler.elaboration.expressions.block.IncludeStatement;
  64 import org.simantics.scl.compiler.elaboration.expressions.block.LetStatement;
  65 import org.simantics.scl.compiler.elaboration.expressions.block.RuleStatement;
  66 import org.simantics.scl.compiler.elaboration.expressions.block.Statement;
  67 import org.simantics.scl.compiler.elaboration.expressions.list.ListAssignment;
  68 import org.simantics.scl.compiler.elaboration.expressions.list.ListGenerator;
  69 import org.simantics.scl.compiler.elaboration.expressions.list.ListGuard;
  70 import org.simantics.scl.compiler.elaboration.expressions.list.ListQualifier;
  71 import org.simantics.scl.compiler.elaboration.expressions.list.ListSeq;
  72 import org.simantics.scl.compiler.elaboration.expressions.list.ListThen;
  73 import org.simantics.scl.compiler.elaboration.expressions.records.FieldAssignment;
  74 import org.simantics.scl.compiler.elaboration.java.Builtins;
  75 import org.simantics.scl.compiler.elaboration.query.QAlternative;
  76 import org.simantics.scl.compiler.elaboration.query.QConjunction;
  77 import org.simantics.scl.compiler.elaboration.query.QDisjunction;
  78 import org.simantics.scl.compiler.elaboration.query.QNegation;
  79 import org.simantics.scl.compiler.elaboration.query.Query;
  80 import org.simantics.scl.compiler.elaboration.query.pre.QPreBinds;
  81 import org.simantics.scl.compiler.elaboration.query.pre.QPreEquals;
  82 import org.simantics.scl.compiler.elaboration.query.pre.QPreGuard;
  83 import org.simantics.scl.compiler.errors.Locations;
  84 import org.simantics.scl.compiler.internal.header.ModuleHeader;
  85 import org.simantics.scl.compiler.internal.parsing.Symbol;
  86 import org.simantics.scl.compiler.internal.parsing.Token;
  87 import org.simantics.scl.compiler.internal.parsing.declarations.ConstructorAst;
  88 import org.simantics.scl.compiler.internal.parsing.declarations.DAnnotationAst;
  89 import org.simantics.scl.compiler.internal.parsing.declarations.DClassAst;
  90 import org.simantics.scl.compiler.internal.parsing.declarations.DDataAst;
  91 import org.simantics.scl.compiler.internal.parsing.declarations.DDerivingInstanceAst;
  92 import org.simantics.scl.compiler.internal.parsing.declarations.DDocumentationAst;
  93 import org.simantics.scl.compiler.internal.parsing.declarations.DEffectAst;
  94 import org.simantics.scl.compiler.internal.parsing.declarations.DFixityAst;
  95 import org.simantics.scl.compiler.internal.parsing.declarations.DImportJavaAst;
  96 import org.simantics.scl.compiler.internal.parsing.declarations.DInstanceAst;
  97 import org.simantics.scl.compiler.internal.parsing.declarations.DMappingRelationAst;
  98 import org.simantics.scl.compiler.internal.parsing.declarations.DRelationAst;
  99 import org.simantics.scl.compiler.internal.parsing.declarations.DRuleAst;
 100 import org.simantics.scl.compiler.internal.parsing.declarations.DRulesetAst;
 101 import org.simantics.scl.compiler.internal.parsing.declarations.DTypeAst;
 102 import org.simantics.scl.compiler.internal.parsing.declarations.DValueAst;
 103 import org.simantics.scl.compiler.internal.parsing.declarations.DValueTypeAst;
 104 import org.simantics.scl.compiler.internal.parsing.declarations.DeclarationAst;
 105 import org.simantics.scl.compiler.internal.parsing.declarations.FieldDescription;
 106 import org.simantics.scl.compiler.internal.parsing.declarations.FundepAst;
 107 import org.simantics.scl.compiler.internal.parsing.exceptions.SCLSyntaxErrorException;
 108 import org.simantics.scl.compiler.internal.parsing.types.TApplyAst;
 109 import org.simantics.scl.compiler.internal.parsing.types.TEffectAst;
 110 import org.simantics.scl.compiler.internal.parsing.types.TForAllAst;
 111 import org.simantics.scl.compiler.internal.parsing.types.TFunctionAst;
 112 import org.simantics.scl.compiler.internal.parsing.types.TListAst;
 113 import org.simantics.scl.compiler.internal.parsing.types.TPredAst;
 114 import org.simantics.scl.compiler.internal.parsing.types.TTupleAst;
 115 import org.simantics.scl.compiler.internal.parsing.types.TVarAst;
 116 import org.simantics.scl.compiler.internal.parsing.types.TypeAst;
 117 import org.simantics.scl.compiler.module.ImportDeclaration;
 118 import org.simantics.scl.compiler.types.Types;
 119
 120
 121 public class SCLParserImpl extends SCLParser {
 122
 123     private final SCLPostLexer lexer;
 124     private SCLParserOptions options;
 125     private CompilationContext context;
 126
 127     public SCLParserImpl(Reader reader) {
 128         this.lexer = new SCLPostLexer(reader);
 129     }
 130
 131     public void setCompilationContext(CompilationContext context) {
 132         this.context = context;
 133         lexer.setCompilationContext(context);
 134     }
 135
 136     public void setParserOptions(SCLParserOptions options) {
 137         this.options = options;
 138         lexer.setParserOptions(options);
 139     }
 140
 141     public boolean isEmpty() throws Exception {
 142         return lexer.peekToken().id == SCLTerminals.EOF;
 143     }
 144
 145     @Override
 146     protected Token nextToken() {
 147         try {
 148             Token token = lexer.nextToken();
 149             /*System.out.println("TOKEN " + token.text + " (" + TERMINAL_NAMES[token.id] + ")" +
 150                     " ["
 151                     + Locations.beginOf(token.location) + ".."
 152                     + Locations.endOf(token.location) + "]");*/
 153             return token;
 154         } catch(Exception e) {
 155             if(e instanceof RuntimeException)
 156                 throw (RuntimeException)e;
 157             else
 158                 throw new RuntimeException(e);
 159         }
 160     }
 161
 162     @Override
 163     protected Object reduceDeclarations() {
 164         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2);
 165         for(int i=1;i<length();i+=2)
 166             declarations.add((DeclarationAst)get(i));
 167         return declarations;
 168     }
 169
 170     @Override
 171     protected Object reduceModule() {
 172         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2+1);
 173         for(int i=0;i<length();i+=2) {
 174             DeclarationAst declaration = (DeclarationAst)get(i);
 175             if(declaration == null)
 176                 continue;
 177             declarations.add(declaration);
 178         }
 179         return declarations;
 180     }
 181
 182     @Override
 183     protected Object reduceModuleHeader() {
 184         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
 185         for(int i=0;i<fields.length;++i)
 186             fields[i] = (FieldAssignment)get(2+i*2);
 187         context.header = ModuleHeader.process(context.errorLog, fields);
 188         return null;
 189     }
 190
 191     @Override
 192     protected Object reduceLocalTypeAnnotation() {
 193         if(length() == 1)
 194             return get(0);
 195         return new ETypeAnnotation((Expression)get(0), (TypeAst)get(2));
 196     }
 197
 198     @Override
 199     protected Object reduceTypeAnnotation() {
 200         EVar[] names = new EVar[length()/2];
 201         for(int i=0;i<names.length;++i)
 202             names[i] = (EVar)get(i*2);
 203         return new DValueTypeAst(
 204                 names,
 205                 (TypeAst)get(length()-1)
 206                 );
 207     }
 208
 209     @Override
 210     protected Object reduceValueDefinition() {
 211         Expression rhs = (Expression)get(1);
 212         return new DValueAst((Expression)get(0), rhs);
 213     }
 214
 215     @Override
 216     protected Object reduceDataDefinition() {
 217         int i=2;
 218         ArrayList<String> parameters = new ArrayList<String>();
 219         while(i < length()) {
 220             Token token = (Token)get(i++);
 221             if(token.id != SCLTerminals.ID)
 222                 break;
 223             parameters.add(token.text);
 224         }
 225         ArrayList<ConstructorAst> constructors = new ArrayList<ConstructorAst>();
 226         for(;i < length();i+=2)
 227             constructors.add((ConstructorAst)get(i));
 228         return new DDataAst(
 229                 ((Token)get(1)).text,
 230                 parameters.toArray(new String[parameters.size()]),
 231                 constructors.toArray(new ConstructorAst[constructors.size()]),
 232                 new String[0]
 233                 );
 234     }
 235
 236     @Override
 237     protected Object reduceTypeDefinition() {
 238         int i=2;
 239         ArrayList<String> parameters = new ArrayList<String>();
 240         while(true) {
 241             Token token = (Token)get(i++);
 242             if(token.id != SCLTerminals.ID)
 243                 break;
 244             parameters.add(token.text);
 245         }
 246         return new DTypeAst(
 247                 ((Token)get(1)).text,
 248                 parameters.toArray(new String[parameters.size()]),
 249                 (TypeAst)get(i)
 250                 );
 251     }
 252
 253     @SuppressWarnings("unchecked")
 254     @Override
 255     protected Object reduceClassDefinition() {
 256         int i=1;
 257         ArrayList<TypeAst> context;
 258         if(get(i) instanceof Token)
 259             context = new ArrayList<TypeAst>(0);
 260         else
 261             context = (ArrayList<TypeAst>)get(i++);
 262         String name = ((Token)get(i++)).text;
 263         ArrayList<String> parameters = new ArrayList<String>();
 264         while(i < length()) {
 265             Token token = (Token)get(i);
 266             if(token.id != SCLTerminals.ID)
 267                 break;
 268             parameters.add(token.text);
 269             ++i;
 270         }
 271         ArrayList<DeclarationAst> declarations = null;
 272         FundepAst[] fundeps = FundepAst.EMPTY_ARRAY;
 273         while(i < length()) {
 274             Token token = (Token)get(i++);
 275             if(token.id == SCLTerminals.WHERE) {
 276                 declarations = (ArrayList<DeclarationAst>)get(i++);
 277             }
 278             else if(token.id == SCLTerminals.BAR) {
 279                 fundeps = (FundepAst[])get(i++);
 280             }
 281             else
 282                 throw new InternalCompilerError();
 283         }
 284         return new DClassAst(context, name,
 285                 parameters.toArray(new String[parameters.size()]),
 286                 fundeps,
 287                 declarations);
 288     }
 289
 290     @Override
 291     protected Object reduceFundep() {
 292         String[] from = new String[length()-2];
 293         for(int i=0;i<from.length;++i)
 294             from[i] = ((Token)get(i)).text;
 295         String to = ((Token)get(length()-1)).text;
 296         return new FundepAst(from, to);
 297     }
 298
 299     @Override
 300     protected Object reduceFundeps() {
 301         FundepAst[] fundeps = new FundepAst[(length()+1)/2];
 302         for(int i=0;i<fundeps.length;++i)
 303             fundeps[i] = (FundepAst)get(i*2);
 304         return fundeps;
 305     }
 306
 307     @SuppressWarnings("unchecked")
 308     @Override
 309     protected Object reduceInstanceDefinition() {
 310         int i=1;
 311         ArrayList<TypeAst> context;
 312         if(get(i) instanceof Token)
 313             context = new ArrayList<TypeAst>(0);
 314         else
 315             context = (ArrayList<TypeAst>)get(i++);
 316         Token nameToken = (Token)get(i++);
 317         EVar name = new EVar(nameToken);
 318         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 319         while(i < length()) {
 320             Object symbol = get(i++);
 321             if(symbol instanceof Token)
 322                 break;
 323             parameters.add((TypeAst)symbol);
 324         }
 325         ArrayList<DeclarationAst> declarations = null;
 326         if(i < length())
 327             declarations = (ArrayList<DeclarationAst>)get(i);
 328         return new DInstanceAst(context, name,
 329                 parameters.toArray(new TypeAst[parameters.size()]),
 330                 declarations);
 331     }
 332
 333     @SuppressWarnings("unchecked")
 334     @Override
 335     protected Object reduceDerivingInstanceDefinition() {
 336         int i=2;
 337         ArrayList<TypeAst> context;
 338         if(get(i) instanceof Token)
 339             context = new ArrayList<TypeAst>(0);
 340         else
 341             context = (ArrayList<TypeAst>)get(i++);
 342         Token nameToken = (Token)get(i++);
 343         EVar name = new EVar(nameToken);
 344         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 345         while(i < length()) {
 346             Object symbol = get(i++);
 347             parameters.add((TypeAst)symbol);
 348         }
 349         return new DDerivingInstanceAst(context, name,
 350                 parameters.toArray(new TypeAst[parameters.size()]));
 351     }
 352
 353     @Override
 354     protected Object reduceDocumentationString() {
 355         return new DDocumentationAst(((Token)get(1)).text);
 356     }
 357
 358     @Override
 359     protected Object reduceAnnotation() {
 360         ArrayList<Expression> parameters = new ArrayList<Expression>(length()-1);
 361         for(int i=1;i<length();++i)
 362             parameters.add((Expression)get(i));
 363         return new DAnnotationAst((Token)get(0), parameters);
 364     }
 365
 366     @Override
 367     protected Object reducePrecedenceDefinition() {
 368         EVar[] symbols = new EVar[length()/2];
 369         for(int i=0;i<symbols.length;++i)
 370             symbols[i] = (EVar)get(2*i + 2);
 371         Associativity associativity;
 372         Token token = (Token)get(0);
 373         if(token.text.equals("infixl"))
 374             associativity = Associativity.LEFT;
 375         else if(token.text.equals("infixr"))
 376             associativity = Associativity.RIGHT;
 377         else
 378             associativity = Associativity.NONASSOC;
 379         return new DFixityAst(
 380                 new Precedence(
 381                         Integer.parseInt(((Token)get(1)).text),
 382                         associativity),
 383                         symbols);
 384     }
 385
 386     @Override
 387     protected Object reduceImport() {
 388         // (AS ID)? importSpec?
 389         int pos = 0;
 390         String importKeyword = ((Token)get(pos++)).text; // (IMPORT | INCLUDE)
 391         ++pos; // BEGIN_STRING
 392         String moduleName = ((Token)get(pos++)).text; // END_STRING
 393         String localName = "";
 394         if(pos < length()) {
 395             Object temp = get(pos);
 396             if(temp instanceof Token) {
 397                 Token token = (Token)temp;
 398                 if(token.id == SCLTerminals.AS) {
 399                     ++pos; // AS
 400                     localName = ((Token)get(pos++)).text; // ID
 401                 }
 402             }
 403         }
 404         ImportDeclaration.ImportSpec spec = ImportDeclaration.DEFAULT_SPEC;
 405         if(pos < length())
 406             spec = (ImportDeclaration.ImportSpec)get(pos++);
 407         return new ImportDeclaration(moduleName, localName,
 408                         importKeyword.equals("include"),
 409                         spec);
 410     }
 411
 412     @Override
 413     protected Object reduceJustImport() {
 414         return get(0);
 415     }
 416
 417     @SuppressWarnings("unchecked")
 418     @Override
 419     protected Object reduceImportJava() {
 420         return new DImportJavaAst(((Token)get(2)).text, (ArrayList<DeclarationAst>)get(4));
 421     }
 422
 423     @Override
 424     protected Object reduceEffectDefinition() {
 425         return new DEffectAst(
 426                 ((Token)get(1)).text,
 427                 ((Token)get(3)).text,
 428                 ((Token)get(5)).text);
 429     }
 430
 431     @Override
 432     protected Object reduceVarId() {
 433         return new EVar((Token)get(0));
 434     }
 435
 436     @Override
 437     protected Object reduceEscapedSymbol() {
 438         return new EVar((Token)get(0));
 439     }
 440
 441     @Override
 442     protected Object reduceTupleTypeConstructor() {
 443         return new TVarAst(Types.tupleConstructor(length()-1).name);
 444     }
 445
 446     @Override
 447     protected Object reduceArrow() {
 448         int i=length()-1;
 449         TypeAst result = (TypeAst)get(i);
 450         i-=2;
 451         while(i >= 0) {
 452             if( ((Token)get(i+1)).text.equals("=>") )
 453                 result = new TPredAst((TypeAst)get(i), result);
 454             else
 455                 result = new TFunctionAst((TypeAst)get(i), result);
 456             i-=2;
 457         }
 458         return result;
 459     }
 460
 461     @Override
 462     protected Object reduceBinary() {
 463         if(length() == 1)
 464             return get(0);
 465         int i=0;
 466         EVar negation = null;
 467         if(get(i) instanceof Token) {
 468             Token token = (Token)get(i++);
 469             negation = new EVar(token);
 470         }
 471         EBinary binary = new EBinary((Expression)get(i++), negation);
 472         while(i < length()) {
 473             EVar operator = (EVar)get(i++);
 474             Expression right = (Expression)get(i++);
 475             binary.rights.add(new EBinaryRightSide(operator, right));
 476         }
 477         return binary;
 478     }
 479
 480     @Override
 481     protected Object reduceSimpleRhs() {
 482         if(length() == 2)
 483             return get(1);
 484         else {
 485             EBlock block = (EBlock)get(3);
 486             Expression expression = (Expression)get(1);
 487             block.addStatement(new GuardStatement(expression));
 488             block.location = Locations.location(Locations.beginOf(expression.location), Locations.endOf(block.location));
 489             return block;
 490         }
 491     }
 492
 493     private GuardedExpressionGroup reduceGuardedExpressionGroup(int length) {
 494         GuardedExpression[] expressions = new GuardedExpression[length];
 495         for(int i=0;i<expressions.length;++i) {
 496             expressions[i] = (GuardedExpression)get(i);
 497         }
 498         return new GuardedExpressionGroup(expressions);
 499     }
 500
 501     @Override
 502     protected Object reduceGuardedRhs() {
 503         int length = length();
 504         if(length > 2 && get(length-2) instanceof Token) {
 505             EBlock block = (EBlock)get(length-1);
 506             block.addStatement(new GuardStatement(reduceGuardedExpressionGroup(length-2)));
 507             block.location = Locations.NO_LOCATION;
 508             return block;
 509         }
 510         else
 511             return reduceGuardedExpressionGroup(length);
 512     }
 513
 514     @Override
 515     protected Object reduceStatements() {
 516         EBlock block = new EBlock();
 517         if(length() > 2)
 518             for(int i=1;i<length();i+=2)
 519                 block.addStatement((Statement)get(i));
 520         return block;
 521     }
 522
 523     @Override
 524     protected Object reduceConstructor() {
 525         int idPos;
 526         for(idPos=0;idPos<length();idPos+=2)
 527             if(((Token)get(idPos)).id == SCLTerminals.ID)
 528                 break;
 529         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
 530         for(int i=0;i<idPos/2;++i)
 531             annotations[i] = new DAnnotationAst((Token)get(i*2),
 532                     Arrays.asList((Expression)get(i*2+1)));
 533         TypeAst[] parameters = new TypeAst[length()-idPos-1];
 534         for(int i=0;i<parameters.length;++i)
 535             parameters[i] = (TypeAst)get(i+idPos+1);
 536         return new ConstructorAst(annotations, (Token)get(idPos), parameters, null);
 537     }
 538
 539     @Override
 540     protected Object reduceContext() {
 541         ArrayList<TypeAst> result = new ArrayList<TypeAst>(length()/2-1);
 542         for(int i=1;i<length()-2;i+=2)
 543             result.add((TypeAst)get(i));
 544         return result;
 545     }
 546
 547     @Override
 548     protected Object reduceTypeVar() {
 549         return new TVarAst(((Token)get(0)).text);
 550     }
 551
 552     @Override
 553     protected Object reduceTupleType() {
 554         if(length() == 2)
 555             return new TTupleAst(TypeAst.EMPTY_ARRAY);
 556         if(length() == 3) {
 557             Symbol sym = (Symbol)get(1);
 558             sym.location = Locations.NO_LOCATION;
 559             return sym;
 560         }
 561         int dim = length()/2;
 562         TypeAst[] parameters = new TypeAst[dim];
 563         for(int i=0;i<dim;++i)
 564             parameters[i] = (TypeAst)get(i*2+1);
 565         return new TTupleAst(parameters);
 566     }
 567
 568     @Override
 569     protected Object reduceListType() {
 570         return new TListAst((TypeAst)get(1));
 571     }
 572
 573     @Override
 574     protected Object reduceListTypeConstructor() {
 575         return new TVarAst("[]");
 576     }
 577
 578     @Override
 579     protected Object reduceTupleConstructor() {
 580         return new EVar(Types.tupleConstructor(length()-1).name);
 581     }
 582
 583     @Override
 584     protected Object reduceVar() {
 585         return get(0);
 586     }
 587
 588     @Override
 589     protected Object reduceBlank() {
 590         return new EVar(((Token)get(0)).location, "_");
 591     }
 592
 593     @Override
 594     protected Object reduceInteger() {
 595         return new EIntegerLiteral(((Token)get(0)).text);
 596     }
 597
 598     @Override
 599     protected Object reduceFloat() {
 600         return new ERealLiteral(((Token)get(0)).text);
 601     }
 602
 603     @Override
 604     protected Object reduceString() {
 605         return get(0);
 606     }
 607
 608     @Override
 609     protected Object reduceChar() {
 610         String text = ((Token)get(0)).text;
 611         char c = text.charAt(text.length()-2);
 612         if(text.length() == 4) {
 613             switch(c) {
 614             case 'n': c = '\n'; break;
 615             case 't': c = '\t'; break;
 616             case 'b': c = '\b'; break;
 617             case 'f': c = '\f'; break;
 618             case 'r': c = '\r'; break;
 619             }
 620         }
 621         return new ELiteral(new CharacterConstant(c));
 622     }
 623
 624     @Override
 625     protected Object reduceTuple() {
 626         if(length() == 2)
 627             return new EConstant(Builtins.TUPLE_CONSTRUCTORS[0]);
 628         if(length() == 3) {
 629             Symbol sym = (Symbol)get(1);
 630             sym.location = Locations.NO_LOCATION;
 631             return sym;
 632         }
 633         int dim = length()/2;
 634         Expression[] parameters = new Expression[dim];
 635         for(int i=0;i<dim;++i)
 636             parameters[i] = (Expression)get(i*2+1);
 637         EConstant tupleConstructor = new EConstant(Builtins.TUPLE_CONSTRUCTORS[dim]);
 638         tupleConstructor.location = Locations.location(
 639                 Locations.beginOf(((Token)get(0)).location),
 640                 Locations.endOf(((Token)get(length()-1)).location));
 641         return new EApply(tupleConstructor, parameters);
 642     }
 643
 644     public static Expression rightSection(EVar op, Expression e) {
 645         long loc = Locations.combine(op.location, e.location);
 646         Variable var = new Variable("rightSectionTemp");
 647         return new ESimpleLambda(loc, var,
 648                 new EApply(loc, op, new EVariable(loc, var), e));
 649     }
 650
 651     @Override
 652     protected Object reduceRightSection() {
 653         Variable var = new Variable("rightSectionTemp");
 654         long loc = Locations.combine(((Token)get(0)).location, ((Token)get(length()-1)).location);
 655         EVar symbol = (EVar)get(1);
 656         return new ESimpleLambda(var,
 657                 new EApply(loc, symbol,
 658                         new EVariable(loc, var), (Expression)get(2)));
 659     }
 660
 661     @Override
 662     protected Object reduceLeftSection() {
 663         return new EApply((EVar)get(2), (Expression)get(1));
 664     }
 665
 666     @Override
 667     protected Object reduceListLiteral() {
 668         if(length() == 2)
 669             return new EListLiteral(Expression.EMPTY_ARRAY);
 670         int dim = length()/2;
 671         Expression[] components = new Expression[dim];
 672         for(int i=0;i<dim;++i)
 673             components[i] = (Expression)get(i*2+1);
 674         return new EListLiteral(components);
 675     }
 676
 677     @Override
 678     protected Object reduceRange() {
 679         return new ERange(
 680                 (Expression)get(1),
 681                 (Expression)get(3)
 682                 );
 683     }
 684
 685     @Override
 686     protected Object reduceListComprehension() {
 687         ListQualifier qualifier = (ListQualifier)get(3);
 688         for(int i=5;i<length();i+=2) {
 689             ListQualifier right = (ListQualifier)get(i);
 690             if(right instanceof ListThen) {
 691                 ((ListThen) right).setLeft(qualifier);
 692                 qualifier = right;
 693             }
 694             else
 695                 qualifier = new ListSeq(qualifier, right);
 696         }
 697         return new EListComprehension((Expression)get(1), qualifier);
 698     }
 699
 700     @Override
 701     protected Object reduceAs() {
 702         Token id = (Token)get(0);
 703         return new EAsPattern(new EVar(id.location, id.text), (Expression)get(2));
 704     }
 705
 706     @Override
 707     protected Object reduceGuardedExpEq() {
 708         Expression[] guards = new Expression[length()/2-1];
 709         for(int i=0;i<guards.length;++i)
 710             guards[i] = (Expression)get(i*2+1);
 711         return new GuardedExpression(guards, (Expression)get(length()-1));
 712     }
 713
 714     @Override
 715     protected Object reduceLambda() {
 716         Expression[] patterns = new Expression[length()-3];
 717         for(int i=0;i<patterns.length;++i)
 718             patterns[i] = (Expression)get(i+1);
 719         Case case_ = new Case(patterns, (Expression)get(length()-1));
 720         case_.setLhs(Locations.combine(patterns[0].location, patterns[patterns.length-1].location));
 721         return new ELambda(case_);
 722     }
 723
 724     @Override
 725     protected Object reduceLambdaMatch() {
 726         Case[] cases = new Case[length()/2-1];
 727         for(int i=0;i<cases.length;++i)
 728             cases[i] = (Case)get(i*2+2);
 729         return new ELambda(cases);
 730     }
 731
 732     @Override
 733     protected Object reduceLet() {
 734         EBlock block = (EBlock)get(1);
 735         Expression expression = (Expression)get(3);
 736         block.addStatement(new GuardStatement(expression));
 737         Token letToken = (Token)get(0);
 738         block.location = Locations.location(
 739                 Locations.beginOf(letToken.location),
 740                 Locations.endOf(expression.location));
 741         return block;
 742     }
 743
 744     @Override
 745     protected Object reduceIf() {
 746         return new EIf(
 747                 (Expression)get(1),
 748                 (Expression)get(3),
 749                 length() == 6 ? (Expression)get(5) : null);
 750     }
 751
 752     @Override
 753     protected Object reduceMatch() {
 754         Case[] cases = new Case[length()/2-2];
 755         for(int i=0;i<cases.length;++i)
 756             cases[i] = (Case)get(i*2+4);
 757         return new EMatch((Expression)get(1), cases);
 758     }
 759
 760     @Override
 761     protected Object reduceDo() {
 762         EBlock block = (EBlock)get(1);
 763         Token doToken = (Token)get(0);
 764         block.setMonadic( doToken.text.equals("mdo") );
 765         block.location = Locations.location(Locations.beginOf(doToken.location), Locations.endOf(block.location));
 766         return block;
 767     }
 768
 769     @Override
 770     protected Object reduceSelect() {
 771         return new ESelect(((Token)get(0)).id, (Expression)get(1), new QConjunction((Query[])get(3)));
 772     }
 773
 774     @Override
 775     protected Object reduceEnforce() {
 776         return new EEnforce(new QConjunction((Query[])get(1)));
 777     }
 778
 779     @Override
 780     protected Object reduceApply() {
 781         if(length() == 1)
 782             return get(0);
 783         Expression[] parameters = new Expression[length()-1];
 784         for(int i=0;i<parameters.length;++i)
 785             parameters[i] = (Expression)get(i+1);
 786         return new EApply((Expression)get(0), parameters);
 787     }
 788
 789     @Override
 790     protected Object reduceSymbol() {
 791         return new EVar(((Token)get(0)).text);
 792     }
 793
 794     @Override
 795     protected Object reduceEscapedId() {
 796         return new EVar(((Token)get(0)).text);
 797     }
 798
 799     @Override
 800     protected Object reduceMinus() {
 801         return new EVar(((Token)get(0)).text);
 802     }
 803
 804     @Override
 805     protected Object reduceLess() {
 806         return new EVar(((Token)get(0)).text);
 807     }
 808
 809     @Override
 810     protected Object reduceGreater() {
 811         return new EVar(((Token)get(0)).text);
 812     }
 813
 814     @Override
 815     protected Object reduceDot() {
 816         return new EVar(((Token)get(0)).text);
 817     }
 818
 819     @Override
 820     protected Object reduceCase() {
 821         return new Case((Expression)get(0), (Expression)get(1));
 822     }
 823
 824     @Override
 825     protected Object reduceGuardQualifier() {
 826         return new ListGuard((Expression)get(0));
 827     }
 828
 829     @Override
 830     protected Object reduceLetQualifier() {
 831         return new ListAssignment((Expression)get(0), (Expression)get(2));
 832     }
 833
 834     @Override
 835     protected Object reduceBindQualifier() {
 836         return new ListGenerator((Expression)get(0), (Expression)get(2));
 837     }
 838
 839     @Override
 840     protected Object reduceThenQualifier() {
 841         return new ListThen((Expression)get(1), length()==4 ? (Expression)get(3) : null);
 842     }
 843
 844     @Override
 845     protected Object reduceGuardStatement() {
 846         return new GuardStatement((Expression)get(0));
 847     }
 848
 849     @Override
 850     protected Object reduceLetStatement() {
 851         return new LetStatement((Expression)get(0), (Expression)get(1));
 852     }
 853
 854     @Override
 855     protected Object reduceBindStatement() {
 856         return new BindStatement((Expression)get(0), (Expression)get(2));
 857     }
 858
 859     @Override
 860     protected Object reduceSimpleCaseRhs() {
 861         return get(1);
 862     }
 863
 864     @Override
 865     protected Object reduceGuardedCaseRhs() {
 866         GuardedExpression[] expressions = new GuardedExpression[length()];
 867         for(int i=0;i<expressions.length;++i)
 868             expressions[i] = (GuardedExpression)get(i);
 869         return new GuardedExpressionGroup(expressions);
 870     }
 871
 872     @Override
 873     protected Object reduceGuardedExpArrow() {
 874         Expression[] guards = new Expression[length()/2-1];
 875         for(int i=0;i<guards.length;++i)
 876             guards[i] = (Expression)get(i*2+1);
 877         return new GuardedExpression(guards, (Expression)get(length()-1));
 878     }
 879
 880     @Override
 881     protected Object reduceEffect() {
 882         ArrayList<TypeAst> effects = new ArrayList<TypeAst>(length()/2-1);
 883         for(int i=1;i<length()-1;i+=2) {
 884             Token token = (Token)get(i);
 885             TVarAst ast = new TVarAst(token.text);
 886             ast.location = token.location;
 887             effects.add(ast);
 888         }
 889         return new TEffectAst(effects, (TypeAst)get(length()-1));
 890     }
 891
 892     @Override
 893     protected Object reduceJustEtype() {
 894         return get(0);
 895     }
 896
 897     @Override
 898     protected Object reduceForAll() {
 899         String[] vars = new String[length()-3];
 900         for(int i=0;i<vars.length;++i)
 901             vars[i] = ((Token)get(i+1)).text;
 902         return new TForAllAst(vars, (TypeAst)get(length()-1));
 903     }
 904
 905     @Override
 906     protected Object reduceApplyType() {
 907         TypeAst[] parameters = new TypeAst[length()-1];
 908         for(int i=0;i<parameters.length;++i)
 909             parameters[i] = (TypeAst)get(i+1);
 910         return new TApplyAst((TypeAst)get(0), parameters);
 911     }
 912
 913     @SuppressWarnings("unchecked")
 914     @Override
 915     protected void postReduce(Object reduced) {
 916         if(!(reduced instanceof Symbol))
 917             return;
 918         Symbol sym = (Symbol)reduced;
 919         if(sym.location != Locations.NO_LOCATION || length() == 0)
 920             return;
 921         Object first = get(0);
 922         if(!(first instanceof Symbol)) {
 923             if(first instanceof List) {
 924                 List<Object> ll = (List<Object>)first;
 925                 first = ll.get(0);
 926             }
 927             else {
 928                 Object[] ll = (Object[])first;
 929                 if(ll.length > 0)
 930                     first = ll[0];
 931                 else
 932                     first = get(1);
 933             }
 934         }
 935         Object last = get(length()-1);
 936         if(!(last instanceof Symbol)) {
 937             if(last instanceof List) {
 938                 List<Object> ll = (List<Object>)last;
 939                 last = ll.get(ll.size()-1);
 940             }
 941             else {
 942                 Object[] ll = (Object[])last;
 943                 if(ll.length > 0)
 944                     last = ll[ll.length-1];
 945                 else
 946                     last = get(length()-2);
 947             }
 948         }
 949         sym.location = (((Symbol)first).location & 0xffffffff00000000L)
 950                 | (((Symbol)last).location & 0xffffffffL);
 951         /*for(int i=0;i<length();++i) {
 952             Object obj = get(i);
 953             System.out.print(obj.getClass().getSimpleName());
 954             if(obj instanceof Token) {
 955                 Token t = (Token)obj;
 956                 System.out.print("(" + t.text + ")");
 957             }
 958             if(obj instanceof Symbol) {
 959                 Symbol s = (Symbol)obj;
 960                 System.out.print("["+ Locations.beginOf(s.location) + "-" + Locations.endOf(s.location) + "]");
 961             }
 962             System.out.print(" ");
 963         }
 964         System.out.println("-> " + reduced.getClass().getSimpleName() + " " +
 965                 Locations.beginOf(sym.location) + "-" + Locations.endOf(sym.location));*/
 966     }
 967
 968     @Override
 969     protected RuntimeException syntaxError(Token token, String description) {
 970         throw new SCLSyntaxErrorException(token.location, description);
 971     }
 972
 973     @Override
 974     protected Object reduceIdAccessor() {
 975         return new IdAccessor('.', ((Token)get(0)).text);
 976     }
 977
 978     @Override
 979     protected Object reduceStringAccessor() {
 980         return new StringAccessor('.', ((Token)get(1)).text);
 981     }
 982
 983     @Override
 984     protected Object reduceExpAccessor() {
 985         return new ExpressionAccessor('.', (Expression)get(1));
 986     }
 987
 988     @Override
 989     protected Object reduceFieldAccess() {
 990         if(length() == 1)
 991             return get(0);
 992         Expression result = (Expression)get(0);
 993         for(int i=2;i<length();i+=2) {
 994             FieldAccessor accessor = (FieldAccessor)get(i);
 995             accessor.accessSeparator = ((Token)get(i-1)).text.charAt(0);
 996             result = new EFieldAccess(result, accessor);
 997         }
 998         return result;
 999     }
1000
1001     @Override
1002     protected Object reduceQueryBlock() {
1003         if(length() == 2)
1004             return Query.EMPTY_ARRAY;
1005         Query[] queries = new Query[length()/2];
1006         for(int i=0;i<queries.length;++i)
1007             queries[i] = (Query)get(2*i+1);
1008         return queries;
1009     }
1010
1011     @Override
1012     protected Object reduceGuardQuery() {
1013         return new QPreGuard((Expression)get(0));
1014     }
1015
1016     @Override
1017     protected Object reduceEqualsQuery() {
1018         return new QPreEquals((Expression)get(0), (Expression)get(2));
1019     }
1020
1021     @Override
1022     protected Object reduceBindQuery() {
1023         return new QPreBinds((Expression)get(0), (Expression)get(2));
1024     }
1025
1026     @Override
1027     protected Object reduceCompositeQuery() {
1028         Query[] queries = (Query[])get(1);
1029         switch(((Token)get(0)).text.charAt(1)) {
1030         case '&': return new QConjunction(queries);
1031         case '|': return new QDisjunction(queries);
1032         case '!': return new QNegation(new QConjunction(queries));
1033         case '?': return new QAlternative(queries);
1034         default: throw new InternalCompilerError();
1035         }
1036     }
1037
1038     @Override
1039     protected Object reduceRuleStatement() {
1040         return new RuleStatement((Expression)get(0), new QConjunction((Query[])get(2)));
1041     }
1042
1043     @Override
1044     protected Object reduceHashedId() {
1045         return new EVar("#" + ((Token)get(1)).text);
1046     }
1047
1048     @Override
1049     protected Object reduceStringLiteral() {
1050         int expCount = length()/3;
1051         if(expCount == 0)
1052             return new ELiteral(new StringConstant(((Token)get(1)).text));
1053         else {
1054             String[] strings = new String[expCount+1];
1055             Expression[] expressions = new Expression[expCount];
1056             for(int i=0;i<expCount;++i) {
1057                 strings[i] = ((Token)get(i*3+1)).text;
1058                 expressions[i] = (Expression)get(i*3+2);
1059             }
1060             strings[expCount] = ((Token)get(expCount*3+1)).text;
1061             return new EStringLiteral(strings, expressions);
1062         }
1063     }
1064
1065     @Override
1066     protected Object reduceOneCommand() {
1067         return null;
1068     }
1069
1070     @Override
1071     protected Object reduceManyCommands() {
1072         return null;
1073     }
1074
1075     @Override
1076     protected Object reduceStatementCommand() {
1077         // to be extended in subclasses
1078         return null;
1079     }
1080
1081     @Override
1082     protected Object reduceImportCommand() {
1083         // to be extended in subclasses
1084         return null;
1085     }
1086
1087     @Override
1088     protected Object reduceImportValueItem() {
1089         return new EVar(((Token)get(0)).text);
1090     }
1091
1092     @Override
1093     protected Object reduceImportHiding() {
1094         EVar[] values = new EVar[(length()-2)/2];
1095         for(int i=0;i<values.length;++i)
1096             values[i] = (EVar)get(i*2+2);
1097         return new ImportDeclaration.ImportSpec(true, values);
1098     }
1099
1100     @Override
1101     protected Object reduceImportShowing() {
1102         EVar[] values = new EVar[(length()-1)/2];
1103         for(int i=0;i<values.length;++i)
1104             values[i] = (EVar)get(i*2+1);
1105         return new ImportDeclaration.ImportSpec(false, values);
1106     }
1107
1108     @Override
1109     protected Object reduceRuleDeclarations() {
1110         ArrayList<Object> declarations = new ArrayList<Object>(length()/2);
1111         for(int i=1;i<length();i+=2)
1112             declarations.add((Object)get(i));
1113         return declarations;
1114     }
1115
1116     private static final String[] EMPTY_STRING_ARRAY = new String[0];
1117
1118     @SuppressWarnings("unchecked")
1119     @Override
1120     protected Object reduceRuleDefinition() {
1121         String[] extendsNames = EMPTY_STRING_ARRAY;
1122         if(length() >= 6) {
1123             int extendsCount = (length() - 4) / 2;
1124             extendsNames = new String[extendsCount];
1125             for(int i=0;i<extendsCount;++i)
1126                 extendsNames[i] = ((Token)get(3+i*2)).text;
1127         }
1128
1129         DRuleAst rule = new DRuleAst(
1130                 ((Token)get(0)).id == SCLTerminals.ABSTRACT_RULE,
1131                 ((Token)get(1)).text,
1132                 extendsNames);
1133
1134         ArrayList<Object> ruleDeclarations = (ArrayList<Object>)get(length()-1);
1135         ArrayList<Query> section = null;
1136         for(Object decl : ruleDeclarations) {
1137             if(decl instanceof DAnnotationAst) {
1138                 DAnnotationAst annotation = (DAnnotationAst)decl;
1139                 section = rule.getSection(annotation.id.text.substring(1));
1140             }
1141             else if(decl instanceof Query) {
1142                 if(section == null)
1143                     section = rule.getSection("when");
1144                 section.add((Query)decl);
1145             }
1146             else
1147                 throw new InternalCompilerError();
1148         }
1149         return rule;
1150     }
1151
1152     @Override
1153     protected Object reduceQueryRuleDeclaration() {
1154         return get(0);
1155     }
1156
1157     @Override
1158     protected Object reduceMappingRelationDefinition() {
1159         TypeAst[] types = new TypeAst[length()-2];
1160         for(int i=0;i<types.length;++i)
1161             types[i] = (TypeAst)get(i+2);
1162         return new DMappingRelationAst(
1163                 ((Token)get(1)).text,
1164                 types);
1165     }
1166
1167     @Override
1168     protected Object reduceTransformation() {
1169         return new ETransformation(
1170                 ((Token)get(1)).text,
1171                 new QConjunction((Query[])get(3))
1172                 );
1173     }
1174
1175     @SuppressWarnings("unchecked")
1176     @Override
1177     protected Object reduceRelationDefinition() {
1178         return new DRelationAst((Expression)get(0),
1179                 ((ArrayList<Object>)get(2)).toArray());
1180     }
1181
1182     @Override
1183     protected Object reduceRecord() {
1184         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
1185         for(int i=0;i<fields.length;++i)
1186             fields[i] = (FieldAssignment)get(2+i*2);
1187         return new ERecord(new EVar((Token)get(0)), fields);
1188     }
1189
1190     @Override
1191     protected Object reduceField() {
1192         return new FieldAssignment(((Token)get(0)).text, (Expression)get(2));
1193     }
1194
1195     @Override
1196     protected Object reduceFieldShorthand() {
1197         return new FieldAssignment(((Token)get(0)).text, null);
1198     }
1199
1200     @Override
1201     protected Object reduceRecordConstructor() {
1202         int idPos;
1203         for(idPos=0;idPos<length();idPos+=2)
1204             if(((Token)get(idPos)).id == SCLTerminals.ID)
1205                 break;
1206         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
1207         for(int i=0;i<idPos/2;++i)
1208             annotations[i] = new DAnnotationAst((Token)get(i*2),
1209                     Arrays.asList((Expression)get(i*2+1)));
1210         TypeAst[] parameters = new TypeAst[(length()-idPos-1)/2];
1211         String[] fieldNames = new String[parameters.length];
1212         for(int i=0;i<parameters.length;++i) {
1213             FieldDescription fieldDesc = (FieldDescription)get(idPos+(i+1)*2);
1214             parameters[i] = fieldDesc.type;
1215             fieldNames[i] = fieldDesc.name;
1216         }
1217         return new ConstructorAst(annotations, (Token)get(idPos), parameters, fieldNames);
1218     }
1219
1220     @Override
1221     protected Object reduceFieldDescription() {
1222         return new FieldDescription(((Token)get(0)).text, (TypeAst)get(2));
1223     }
1224
1225     @Override
1226     protected Object reduceEq() {
1227         return (Expression)get(2);
1228     }
1229
1230     @Override
1231     protected Object reduceEquationBlock() {
1232         if(length() == 0)
1233             return new EEquations(Equation.EMPTY_ARRAY);
1234         Equation[] equations = new Equation[length()/2+1];
1235         for(int i=0;i<equations.length;++i)
1236             equations[i] = (Equation)get(2*i);
1237         return new EEquations(equations);
1238     }
1239
1240     @Override
1241     protected Object reduceGuardEquation() {
1242         return new EqGuard((Expression)get(0));
1243     }
1244
1245     @Override
1246     protected Object reduceBasicEquation() {
1247         return new EqBasic((Expression)get(0), (Expression)get(2));
1248     }
1249
1250     @Override
1251     protected Object reduceViewPattern() {
1252         return new EViewPattern((Expression)get(1), (Expression)get(3));
1253     }
1254
1255     @Override
1256     protected Object reduceConstraintStatement() {
1257         ConstructorAst constructor = (ConstructorAst)get(1);
1258         return new ConstraintStatement(constructor.name, constructor.parameters, constructor.fieldNames, constructor.annotations);
1259     }
1260
1261     /*
1262     @Override
1263     protected Object reduceWhen() {
1264         return new EWhen(
1265                 new QConjunction((Query[])get(1)),
1266                 (Expression)get(3));
1267     }*/
1268
1269     @Override
1270     protected Object reduceDummy() {
1271         throw new UnsupportedOperationException();
1272     }
1273
1274     @Override
1275     protected Object reduceRulesetDefinition() {
1276         Token name = (Token)get(1);
1277         EBlock block = (EBlock)get(3);
1278         return new DRulesetAst(name.text, block);
1279     }
1280
1281     @Override
1282     protected Object reduceLocalInclude() {
1283         Token name = (Token)get(1);
1284         Expression value = (Expression)get(2);
1285         return new IncludeStatement(name, value);
1286     }
1287
1288     /*@Override
1289     protected Object reduceConstraintSpec() {
1290         Expression[] expressions = new Expression[length()/2-1];
1291         for(int i=0;i<expressions.length;++i)
1292             expressions[i] = (Expression)get(2*i+1);
1293         return expressions;
1294     }*/
1295
1296     @Override
1297     protected Object reduceCHRSelect() {
1298         return new EPreCHRSelect((CHRAstQuery)get(3), (Expression)get(1));
1299     }
1300
1301     @Override
1302     protected Object reduceCHRAtom() {
1303         return CHRAstAtom.atom((Expression)get(0));
1304     }
1305
1306     @Override
1307     protected Object reduceCHREquals() {
1308         return new CHRAstEquals((Expression)get(0), (Expression)get(2));
1309     }
1310
1311     @Override
1312     protected Object reduceCHRBinds() {
1313         return new CHRAstBinds((Expression)get(0), (Expression)get(2));
1314     }
1315
1316     @Override
1317     protected Object reduceCHRConjunction() {
1318         CHRAstQuery[] conjuncts = new CHRAstQuery[(length()+1)/2];
1319         for(int i=0;i<conjuncts.length;++i)
1320             conjuncts[i] = (CHRAstQuery)get(i*2);
1321         return CHRAstConjunction.conjunction(conjuncts);
1322     }
1323
1324     @Override
1325     protected Object reduceVerboseCHRConjunction() {
1326         CHRAstQuery[] conjuncts = new CHRAstQuery[(length()-1)/2];
1327         for(int i=0;i<conjuncts.length;++i)
1328             conjuncts[i] = (CHRAstQuery)get(i*2+1);
1329         return CHRAstConjunction.conjunction(conjuncts);
1330     }
1331
1332     @Override
1333     protected Object reduceVerboseCHRStatement() {
1334         return new CHRStatement((CHRAstQuery)get(1), (CHRAstQuery)get(3));
1335     }
1336
1337     @Override
1338     protected Object reduceCHRStatement() {
1339         return new CHRStatement((CHRAstQuery)get(0), (CHRAstQuery)get(2));
1340     }
1341
1342 }