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 SCLPostLexer getLexer() {
 133         return lexer;
 134     }
 135
 136     public void setCompilationContext(CompilationContext context) {
 137         this.context = context;
 138         lexer.setCompilationContext(context);
 139     }
 140
 141     public void setParserOptions(SCLParserOptions options) {
 142         this.options = options;
 143         lexer.setParserOptions(options);
 144     }
 145
 146     public boolean isEmpty() throws Exception {
 147         return lexer.peekToken().id == SCLTerminals.EOF;
 148     }
 149
 150     @Override
 151     protected Token nextToken() {
 152         try {
 153             Token token = lexer.nextToken();
 154             /*System.out.println("TOKEN " + token.text + " (" + TERMINAL_NAMES[token.id] + ")" +
 155                     " ["
 156                     + Locations.beginOf(token.location) + ".."
 157                     + Locations.endOf(token.location) + "]");*/
 158             return token;
 159         } catch(Exception e) {
 160             if(e instanceof RuntimeException)
 161                 throw (RuntimeException)e;
 162             else
 163                 throw new RuntimeException(e);
 164         }
 165     }
 166
 167     @Override
 168     protected Object reduceDeclarations() {
 169         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2);
 170         for(int i=1;i<length();i+=2)
 171             declarations.add((DeclarationAst)get(i));
 172         return declarations;
 173     }
 174
 175     @Override
 176     protected Object reduceModule() {
 177         ArrayList<DeclarationAst> declarations = new ArrayList<DeclarationAst>(length()/2+1);
 178         for(int i=0;i<length();i+=2) {
 179             DeclarationAst declaration = (DeclarationAst)get(i);
 180             if(declaration == null)
 181                 continue;
 182             declarations.add(declaration);
 183         }
 184         return declarations;
 185     }
 186
 187     @Override
 188     protected Object reduceModuleHeader() {
 189         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
 190         for(int i=0;i<fields.length;++i)
 191             fields[i] = (FieldAssignment)get(2+i*2);
 192         context.header = ModuleHeader.process(context.errorLog, fields);
 193         return null;
 194     }
 195
 196     @Override
 197     protected Object reduceLocalTypeAnnotation() {
 198         if(length() == 1)
 199             return get(0);
 200         return new ETypeAnnotation((Expression)get(0), (TypeAst)get(2));
 201     }
 202
 203     @Override
 204     protected Object reduceTypeAnnotation() {
 205         EVar[] names = new EVar[length()/2];
 206         for(int i=0;i<names.length;++i)
 207             names[i] = (EVar)get(i*2);
 208         return new DValueTypeAst(
 209                 names,
 210                 (TypeAst)get(length()-1)
 211                 );
 212     }
 213
 214     @Override
 215     protected Object reduceValueDefinition() {
 216         Expression rhs = (Expression)get(1);
 217         return new DValueAst((Expression)get(0), rhs);
 218     }
 219
 220     @Override
 221     protected Object reduceDataDefinition() {
 222         int i=2;
 223         ArrayList<String> parameters = new ArrayList<String>();
 224         while(i < length()) {
 225             Token token = (Token)get(i++);
 226             if(token.id != SCLTerminals.ID)
 227                 break;
 228             parameters.add(token.text);
 229         }
 230         ArrayList<ConstructorAst> constructors = new ArrayList<ConstructorAst>();
 231         for(;i < length();i+=2)
 232             constructors.add((ConstructorAst)get(i));
 233         return new DDataAst(
 234                 ((Token)get(1)).text,
 235                 parameters.toArray(new String[parameters.size()]),
 236                 constructors.toArray(new ConstructorAst[constructors.size()]),
 237                 new String[0]
 238                 );
 239     }
 240
 241     @Override
 242     protected Object reduceTypeDefinition() {
 243         int i=2;
 244         ArrayList<String> parameters = new ArrayList<String>();
 245         while(true) {
 246             Token token = (Token)get(i++);
 247             if(token.id != SCLTerminals.ID)
 248                 break;
 249             parameters.add(token.text);
 250         }
 251         return new DTypeAst(
 252                 ((Token)get(1)).text,
 253                 parameters.toArray(new String[parameters.size()]),
 254                 (TypeAst)get(i)
 255                 );
 256     }
 257
 258     @SuppressWarnings("unchecked")
 259     @Override
 260     protected Object reduceClassDefinition() {
 261         int i=1;
 262         ArrayList<TypeAst> context;
 263         if(get(i) instanceof Token)
 264             context = new ArrayList<TypeAst>(0);
 265         else
 266             context = (ArrayList<TypeAst>)get(i++);
 267         String name = ((Token)get(i++)).text;
 268         ArrayList<String> parameters = new ArrayList<String>();
 269         while(i < length()) {
 270             Token token = (Token)get(i);
 271             if(token.id != SCLTerminals.ID)
 272                 break;
 273             parameters.add(token.text);
 274             ++i;
 275         }
 276         ArrayList<DeclarationAst> declarations = null;
 277         FundepAst[] fundeps = FundepAst.EMPTY_ARRAY;
 278         while(i < length()) {
 279             Token token = (Token)get(i++);
 280             if(token.id == SCLTerminals.WHERE) {
 281                 declarations = (ArrayList<DeclarationAst>)get(i++);
 282             }
 283             else if(token.id == SCLTerminals.BAR) {
 284                 fundeps = (FundepAst[])get(i++);
 285             }
 286             else
 287                 throw new InternalCompilerError();
 288         }
 289         return new DClassAst(context, name,
 290                 parameters.toArray(new String[parameters.size()]),
 291                 fundeps,
 292                 declarations);
 293     }
 294
 295     @Override
 296     protected Object reduceFundep() {
 297         String[] from = new String[length()-2];
 298         for(int i=0;i<from.length;++i)
 299             from[i] = ((Token)get(i)).text;
 300         String to = ((Token)get(length()-1)).text;
 301         return new FundepAst(from, to);
 302     }
 303
 304     @Override
 305     protected Object reduceFundeps() {
 306         FundepAst[] fundeps = new FundepAst[(length()+1)/2];
 307         for(int i=0;i<fundeps.length;++i)
 308             fundeps[i] = (FundepAst)get(i*2);
 309         return fundeps;
 310     }
 311
 312     @SuppressWarnings("unchecked")
 313     @Override
 314     protected Object reduceInstanceDefinition() {
 315         int i=1;
 316         ArrayList<TypeAst> context;
 317         if(get(i) instanceof Token)
 318             context = new ArrayList<TypeAst>(0);
 319         else
 320             context = (ArrayList<TypeAst>)get(i++);
 321         Token nameToken = (Token)get(i++);
 322         EVar name = new EVar(nameToken);
 323         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 324         while(i < length()) {
 325             Object symbol = get(i++);
 326             if(symbol instanceof Token)
 327                 break;
 328             parameters.add((TypeAst)symbol);
 329         }
 330         ArrayList<DeclarationAst> declarations = null;
 331         if(i < length())
 332             declarations = (ArrayList<DeclarationAst>)get(i);
 333         return new DInstanceAst(context, name,
 334                 parameters.toArray(new TypeAst[parameters.size()]),
 335                 declarations);
 336     }
 337
 338     @SuppressWarnings("unchecked")
 339     @Override
 340     protected Object reduceDerivingInstanceDefinition() {
 341         int i=2;
 342         ArrayList<TypeAst> context;
 343         if(get(i) instanceof Token)
 344             context = new ArrayList<TypeAst>(0);
 345         else
 346             context = (ArrayList<TypeAst>)get(i++);
 347         Token nameToken = (Token)get(i++);
 348         EVar name = new EVar(nameToken);
 349         ArrayList<TypeAst> parameters = new ArrayList<TypeAst>();
 350         while(i < length()) {
 351             Object symbol = get(i++);
 352             parameters.add((TypeAst)symbol);
 353         }
 354         return new DDerivingInstanceAst(context, name,
 355                 parameters.toArray(new TypeAst[parameters.size()]));
 356     }
 357
 358     @Override
 359     protected Object reduceDocumentationString() {
 360         return new DDocumentationAst(((Token)get(1)).text);
 361     }
 362
 363     @Override
 364     protected Object reduceAnnotation() {
 365         ArrayList<Expression> parameters = new ArrayList<Expression>(length()-1);
 366         for(int i=1;i<length();++i)
 367             parameters.add((Expression)get(i));
 368         return new DAnnotationAst((Token)get(0), parameters);
 369     }
 370
 371     @Override
 372     protected Object reducePrecedenceDefinition() {
 373         EVar[] symbols = new EVar[length()/2];
 374         for(int i=0;i<symbols.length;++i)
 375             symbols[i] = (EVar)get(2*i + 2);
 376         Associativity associativity;
 377         Token token = (Token)get(0);
 378         if(token.text.equals("infixl"))
 379             associativity = Associativity.LEFT;
 380         else if(token.text.equals("infixr"))
 381             associativity = Associativity.RIGHT;
 382         else
 383             associativity = Associativity.NONASSOC;
 384         return new DFixityAst(
 385                 new Precedence(
 386                         Integer.parseInt(((Token)get(1)).text),
 387                         associativity),
 388                         symbols);
 389     }
 390
 391     @Override
 392     protected Object reduceImport() {
 393         // (AS ID)? importSpec?
 394         int pos = 0;
 395         String importKeyword = ((Token)get(pos++)).text; // (IMPORT | INCLUDE)
 396         ++pos; // BEGIN_STRING
 397         String moduleName = ((Token)get(pos++)).text; // END_STRING
 398         String localName = "";
 399         if(pos < length()) {
 400             Object temp = get(pos);
 401             if(temp instanceof Token) {
 402                 Token token = (Token)temp;
 403                 if(token.id == SCLTerminals.AS) {
 404                     ++pos; // AS
 405                     localName = ((Token)get(pos++)).text; // ID
 406                 }
 407             }
 408         }
 409         ImportDeclaration.ImportSpec spec = ImportDeclaration.DEFAULT_SPEC;
 410         if(pos < length())
 411             spec = (ImportDeclaration.ImportSpec)get(pos++);
 412         return new ImportDeclaration(moduleName, localName,
 413                         importKeyword.equals("include"),
 414                         spec);
 415     }
 416
 417     @Override
 418     protected Object reduceJustImport() {
 419         return get(0);
 420     }
 421
 422     @SuppressWarnings("unchecked")
 423     @Override
 424     protected Object reduceImportJava() {
 425         return new DImportJavaAst(((Token)get(2)).text, (ArrayList<DeclarationAst>)get(4));
 426     }
 427
 428     @Override
 429     protected Object reduceEffectDefinition() {
 430         return new DEffectAst(
 431                 ((Token)get(1)).text,
 432                 ((Token)get(3)).text,
 433                 ((Token)get(5)).text);
 434     }
 435
 436     @Override
 437     protected Object reduceVarId() {
 438         return new EVar((Token)get(0));
 439     }
 440
 441     @Override
 442     protected Object reduceEscapedSymbol() {
 443         return new EVar((Token)get(0));
 444     }
 445
 446     @Override
 447     protected Object reduceTupleTypeConstructor() {
 448         return new TVarAst(Types.tupleConstructor(length()-1).name);
 449     }
 450
 451     @Override
 452     protected Object reduceArrow() {
 453         int i=length()-1;
 454         TypeAst result = (TypeAst)get(i);
 455         i-=2;
 456         while(i >= 0) {
 457             if( ((Token)get(i+1)).text.equals("=>") )
 458                 result = new TPredAst((TypeAst)get(i), result);
 459             else
 460                 result = new TFunctionAst((TypeAst)get(i), result);
 461             i-=2;
 462         }
 463         return result;
 464     }
 465
 466     @Override
 467     protected Object reduceBinary() {
 468         if(length() == 1)
 469             return get(0);
 470         int i=0;
 471         EVar negation = null;
 472         if(get(i) instanceof Token) {
 473             Token token = (Token)get(i++);
 474             negation = new EVar(token);
 475         }
 476         EBinary binary = new EBinary((Expression)get(i++), negation);
 477         while(i < length()) {
 478             EVar operator = (EVar)get(i++);
 479             Expression right = (Expression)get(i++);
 480             binary.rights.add(new EBinaryRightSide(operator, right));
 481         }
 482         return binary;
 483     }
 484
 485     @Override
 486     protected Object reduceSimpleRhs() {
 487         if(length() == 2)
 488             return get(1);
 489         else {
 490             EBlock block = (EBlock)get(3);
 491             Expression expression = (Expression)get(1);
 492             block.addStatement(new GuardStatement(expression));
 493             block.location = Locations.location(Locations.beginOf(expression.location), Locations.endOf(block.location));
 494             return block;
 495         }
 496     }
 497
 498     private GuardedExpressionGroup reduceGuardedExpressionGroup(int length) {
 499         GuardedExpression[] expressions = new GuardedExpression[length];
 500         for(int i=0;i<expressions.length;++i) {
 501             expressions[i] = (GuardedExpression)get(i);
 502         }
 503         return new GuardedExpressionGroup(expressions);
 504     }
 505
 506     @Override
 507     protected Object reduceGuardedRhs() {
 508         int length = length();
 509         if(length > 2 && get(length-2) instanceof Token) {
 510             EBlock block = (EBlock)get(length-1);
 511             block.addStatement(new GuardStatement(reduceGuardedExpressionGroup(length-2)));
 512             block.location = Locations.NO_LOCATION;
 513             return block;
 514         }
 515         else
 516             return reduceGuardedExpressionGroup(length);
 517     }
 518
 519     @Override
 520     protected Object reduceStatements() {
 521         EBlock block = new EBlock();
 522         if(length() > 2)
 523             for(int i=1;i<length();i+=2)
 524                 block.addStatement((Statement)get(i));
 525         return block;
 526     }
 527
 528     @Override
 529     protected Object reduceConstructor() {
 530         int idPos;
 531         for(idPos=0;idPos<length();idPos+=2)
 532             if(((Token)get(idPos)).id == SCLTerminals.ID)
 533                 break;
 534         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
 535         for(int i=0;i<idPos/2;++i)
 536             annotations[i] = new DAnnotationAst((Token)get(i*2),
 537                     Arrays.asList((Expression)get(i*2+1)));
 538         TypeAst[] parameters = new TypeAst[length()-idPos-1];
 539         for(int i=0;i<parameters.length;++i)
 540             parameters[i] = (TypeAst)get(i+idPos+1);
 541         return new ConstructorAst(annotations, (Token)get(idPos), parameters, null);
 542     }
 543
 544     @Override
 545     protected Object reduceContext() {
 546         ArrayList<TypeAst> result = new ArrayList<TypeAst>(length()/2-1);
 547         for(int i=1;i<length()-2;i+=2)
 548             result.add((TypeAst)get(i));
 549         return result;
 550     }
 551
 552     @Override
 553     protected Object reduceTypeVar() {
 554         return new TVarAst(((Token)get(0)).text);
 555     }
 556
 557     @Override
 558     protected Object reduceTupleType() {
 559         if(length() == 2)
 560             return new TTupleAst(TypeAst.EMPTY_ARRAY);
 561         if(length() == 3) {
 562             Symbol sym = (Symbol)get(1);
 563             sym.location = Locations.NO_LOCATION;
 564             return sym;
 565         }
 566         int dim = length()/2;
 567         TypeAst[] parameters = new TypeAst[dim];
 568         for(int i=0;i<dim;++i)
 569             parameters[i] = (TypeAst)get(i*2+1);
 570         return new TTupleAst(parameters);
 571     }
 572
 573     @Override
 574     protected Object reduceListType() {
 575         return new TListAst((TypeAst)get(1));
 576     }
 577
 578     @Override
 579     protected Object reduceListTypeConstructor() {
 580         return new TVarAst("[]");
 581     }
 582
 583     @Override
 584     protected Object reduceTupleConstructor() {
 585         return new EVar(Types.tupleConstructor(length()-1).name);
 586     }
 587
 588     @Override
 589     protected Object reduceVar() {
 590         return get(0);
 591     }
 592
 593     @Override
 594     protected Object reduceBlank() {
 595         return new EVar(((Token)get(0)).location, "_");
 596     }
 597
 598     @Override
 599     protected Object reduceInteger() {
 600         return new EIntegerLiteral(((Token)get(0)).text);
 601     }
 602
 603     @Override
 604     protected Object reduceFloat() {
 605         return new ERealLiteral(((Token)get(0)).text);
 606     }
 607
 608     @Override
 609     protected Object reduceString() {
 610         return get(0);
 611     }
 612
 613     @Override
 614     protected Object reduceChar() {
 615         String text = ((Token)get(0)).text;
 616         char c = text.charAt(text.length()-2);
 617         if(text.length() == 4) {
 618             switch(c) {
 619             case 'n': c = '\n'; break;
 620             case 't': c = '\t'; break;
 621             case 'b': c = '\b'; break;
 622             case 'f': c = '\f'; break;
 623             case 'r': c = '\r'; break;
 624             }
 625         }
 626         return new ELiteral(new CharacterConstant(c));
 627     }
 628
 629     @Override
 630     protected Object reduceTuple() {
 631         if(length() == 2)
 632             return new EConstant(Builtins.TUPLE_CONSTRUCTORS[0]);
 633         if(length() == 3) {
 634             Symbol sym = (Symbol)get(1);
 635             sym.location = Locations.NO_LOCATION;
 636             return sym;
 637         }
 638         int dim = length()/2;
 639         Expression[] parameters = new Expression[dim];
 640         for(int i=0;i<dim;++i)
 641             parameters[i] = (Expression)get(i*2+1);
 642         EConstant tupleConstructor = new EConstant(Builtins.TUPLE_CONSTRUCTORS[dim]);
 643         tupleConstructor.location = Locations.location(
 644                 Locations.beginOf(((Token)get(0)).location),
 645                 Locations.endOf(((Token)get(length()-1)).location));
 646         return new EApply(tupleConstructor, parameters);
 647     }
 648
 649     public static Expression rightSection(EVar op, Expression e) {
 650         long loc = Locations.combine(op.location, e.location);
 651         Variable var = new Variable("rightSectionTemp");
 652         return new ESimpleLambda(loc, var,
 653                 new EApply(loc, op, new EVariable(loc, var), e));
 654     }
 655
 656     @Override
 657     protected Object reduceRightSection() {
 658         Variable var = new Variable("rightSectionTemp");
 659         long loc = Locations.combine(((Token)get(0)).location, ((Token)get(length()-1)).location);
 660         EVar symbol = (EVar)get(1);
 661         return new ESimpleLambda(var,
 662                 new EApply(loc, symbol,
 663                         new EVariable(loc, var), (Expression)get(2)));
 664     }
 665
 666     @Override
 667     protected Object reduceLeftSection() {
 668         return new EApply((EVar)get(2), (Expression)get(1));
 669     }
 670
 671     @Override
 672     protected Object reduceListLiteral() {
 673         if(length() == 2)
 674             return new EListLiteral(Expression.EMPTY_ARRAY);
 675         int dim = length()/2;
 676         Expression[] components = new Expression[dim];
 677         for(int i=0;i<dim;++i)
 678             components[i] = (Expression)get(i*2+1);
 679         return new EListLiteral(components);
 680     }
 681
 682     @Override
 683     protected Object reduceRange() {
 684         return new ERange(
 685                 (Expression)get(1),
 686                 (Expression)get(3)
 687                 );
 688     }
 689
 690     @Override
 691     protected Object reduceListComprehension() {
 692         ListQualifier qualifier = (ListQualifier)get(3);
 693         for(int i=5;i<length();i+=2) {
 694             ListQualifier right = (ListQualifier)get(i);
 695             if(right instanceof ListThen) {
 696                 ((ListThen) right).setLeft(qualifier);
 697                 qualifier = right;
 698             }
 699             else
 700                 qualifier = new ListSeq(qualifier, right);
 701         }
 702         return new EListComprehension((Expression)get(1), qualifier);
 703     }
 704
 705     @Override
 706     protected Object reduceAs() {
 707         Token id = (Token)get(0);
 708         return new EAsPattern(new EVar(id.location, id.text), (Expression)get(2));
 709     }
 710
 711     @Override
 712     protected Object reduceGuardedExpEq() {
 713         Expression[] guards = new Expression[length()/2-1];
 714         for(int i=0;i<guards.length;++i)
 715             guards[i] = (Expression)get(i*2+1);
 716         return new GuardedExpression(guards, (Expression)get(length()-1));
 717     }
 718
 719     @Override
 720     protected Object reduceLambda() {
 721         Expression[] patterns = new Expression[length()-3];
 722         for(int i=0;i<patterns.length;++i)
 723             patterns[i] = (Expression)get(i+1);
 724         Case case_ = new Case(patterns, (Expression)get(length()-1));
 725         case_.setLhs(Locations.combine(patterns[0].location, patterns[patterns.length-1].location));
 726         return new ELambda(case_);
 727     }
 728
 729     @Override
 730     protected Object reduceLambdaMatch() {
 731         Case[] cases = new Case[length()/2-1];
 732         for(int i=0;i<cases.length;++i)
 733             cases[i] = (Case)get(i*2+2);
 734         return new ELambda(cases);
 735     }
 736
 737     @Override
 738     protected Object reduceLet() {
 739         EBlock block = (EBlock)get(1);
 740         Expression expression = (Expression)get(3);
 741         block.addStatement(new GuardStatement(expression));
 742         Token letToken = (Token)get(0);
 743         block.location = Locations.location(
 744                 Locations.beginOf(letToken.location),
 745                 Locations.endOf(expression.location));
 746         return block;
 747     }
 748
 749     @Override
 750     protected Object reduceIf() {
 751         return new EIf(
 752                 (Expression)get(1),
 753                 (Expression)get(3),
 754                 length() == 6 ? (Expression)get(5) : null);
 755     }
 756
 757     @Override
 758     protected Object reduceMatch() {
 759         Case[] cases = new Case[length()/2-2];
 760         for(int i=0;i<cases.length;++i)
 761             cases[i] = (Case)get(i*2+4);
 762         return new EMatch((Expression)get(1), cases);
 763     }
 764
 765     @Override
 766     protected Object reduceDo() {
 767         EBlock block = (EBlock)get(1);
 768         Token doToken = (Token)get(0);
 769         switch(doToken.text) {
 770         case "mdo":
 771             block.setBlockType(BlockType.Monad);
 772             break;
 773         case "edo":
 774             block.setBlockType(BlockType.MonadE);
 775             break;
 776         }
 777         block.location = Locations.location(Locations.beginOf(doToken.location), Locations.endOf(block.location));
 778         return block;
 779     }
 780
 781     @Override
 782     protected Object reduceSelect() {
 783         return new ESelect(((Token)get(0)).id, (Expression)get(1), new QConjunction((Query[])get(3)));
 784     }
 785
 786     @Override
 787     protected Object reduceEnforce() {
 788         return new EEnforce(new QConjunction((Query[])get(1)));
 789     }
 790
 791     @Override
 792     protected Object reduceApply() {
 793         if(length() == 1)
 794             return get(0);
 795         Expression[] parameters = new Expression[length()-1];
 796         for(int i=0;i<parameters.length;++i)
 797             parameters[i] = (Expression)get(i+1);
 798         return new EApply((Expression)get(0), parameters);
 799     }
 800
 801     @Override
 802     protected Object reduceSymbol() {
 803         return new EVar(((Token)get(0)).text);
 804     }
 805
 806     @Override
 807     protected Object reduceEscapedId() {
 808         return new EVar(((Token)get(0)).text);
 809     }
 810
 811     @Override
 812     protected Object reduceMinus() {
 813         return new EVar(((Token)get(0)).text);
 814     }
 815
 816     @Override
 817     protected Object reduceLess() {
 818         return new EVar(((Token)get(0)).text);
 819     }
 820
 821     @Override
 822     protected Object reduceGreater() {
 823         return new EVar(((Token)get(0)).text);
 824     }
 825
 826     @Override
 827     protected Object reduceDot() {
 828         return new EVar(((Token)get(0)).text);
 829     }
 830
 831     @Override
 832     protected Object reduceCase() {
 833         return new Case((Expression)get(0), (Expression)get(1));
 834     }
 835
 836     @Override
 837     protected Object reduceGuardQualifier() {
 838         return new ListGuard((Expression)get(0));
 839     }
 840
 841     @Override
 842     protected Object reduceLetQualifier() {
 843         return new ListAssignment((Expression)get(0), (Expression)get(2));
 844     }
 845
 846     @Override
 847     protected Object reduceBindQualifier() {
 848         return new ListGenerator((Expression)get(0), (Expression)get(2));
 849     }
 850
 851     @Override
 852     protected Object reduceThenQualifier() {
 853         return new ListThen((Expression)get(1), length()==4 ? (Expression)get(3) : null);
 854     }
 855
 856     @Override
 857     protected Object reduceGuardStatement() {
 858         return new GuardStatement((Expression)get(0));
 859     }
 860
 861     @Override
 862     protected Object reduceLetStatement() {
 863         return new LetStatement((Expression)get(0), (Expression)get(1));
 864     }
 865
 866     @Override
 867     protected Object reduceBindStatement() {
 868         return new BindStatement((Expression)get(0), (Expression)get(2));
 869     }
 870
 871     @Override
 872     protected Object reduceSimpleCaseRhs() {
 873         return get(1);
 874     }
 875
 876     @Override
 877     protected Object reduceGuardedCaseRhs() {
 878         GuardedExpression[] expressions = new GuardedExpression[length()];
 879         for(int i=0;i<expressions.length;++i)
 880             expressions[i] = (GuardedExpression)get(i);
 881         return new GuardedExpressionGroup(expressions);
 882     }
 883
 884     @Override
 885     protected Object reduceGuardedExpArrow() {
 886         Expression[] guards = new Expression[length()/2-1];
 887         for(int i=0;i<guards.length;++i)
 888             guards[i] = (Expression)get(i*2+1);
 889         return new GuardedExpression(guards, (Expression)get(length()-1));
 890     }
 891
 892     @Override
 893     protected Object reduceEffect() {
 894         ArrayList<TypeAst> effects = new ArrayList<TypeAst>(length()/2-1);
 895         for(int i=1;i<length()-1;i+=2) {
 896             Token token = (Token)get(i);
 897             TVarAst ast = new TVarAst(token.text);
 898             ast.location = token.location;
 899             effects.add(ast);
 900         }
 901         return new TEffectAst(effects, (TypeAst)get(length()-1));
 902     }
 903
 904     @Override
 905     protected Object reduceJustEtype() {
 906         return get(0);
 907     }
 908
 909     @Override
 910     protected Object reduceForAll() {
 911         String[] vars = new String[length()-3];
 912         for(int i=0;i<vars.length;++i)
 913             vars[i] = ((Token)get(i+1)).text;
 914         return new TForAllAst(vars, (TypeAst)get(length()-1));
 915     }
 916
 917     @Override
 918     protected Object reduceApplyType() {
 919         TypeAst[] parameters = new TypeAst[length()-1];
 920         for(int i=0;i<parameters.length;++i)
 921             parameters[i] = (TypeAst)get(i+1);
 922         return new TApplyAst((TypeAst)get(0), parameters);
 923     }
 924
 925     @SuppressWarnings("unchecked")
 926     @Override
 927     protected void postReduce(Object reduced) {
 928         if(!(reduced instanceof Symbol))
 929             return;
 930         Symbol sym = (Symbol)reduced;
 931         if(sym.location != Locations.NO_LOCATION || length() == 0)
 932             return;
 933         Object first = get(0);
 934         if(!(first instanceof Symbol)) {
 935             if(first instanceof List) {
 936                 List<Object> ll = (List<Object>)first;
 937                 first = ll.get(0);
 938             }
 939             else {
 940                 Object[] ll = (Object[])first;
 941                 if(ll.length > 0)
 942                     first = ll[0];
 943                 else
 944                     first = get(1);
 945             }
 946         }
 947         Object last = get(length()-1);
 948         if(!(last instanceof Symbol)) {
 949             if(last instanceof List) {
 950                 List<Object> ll = (List<Object>)last;
 951                 last = ll.get(ll.size()-1);
 952             }
 953             else {
 954                 Object[] ll = (Object[])last;
 955                 if(ll.length > 0)
 956                     last = ll[ll.length-1];
 957                 else
 958                     last = get(length()-2);
 959             }
 960         }
 961         sym.location = (((Symbol)first).location & 0xffffffff00000000L)
 962                 | (((Symbol)last).location & 0xffffffffL);
 963         /*for(int i=0;i<length();++i) {
 964             Object obj = get(i);
 965             System.out.print(obj.getClass().getSimpleName());
 966             if(obj instanceof Token) {
 967                 Token t = (Token)obj;
 968                 System.out.print("(" + t.text + ")");
 969             }
 970             if(obj instanceof Symbol) {
 971                 Symbol s = (Symbol)obj;
 972                 System.out.print("["+ Locations.beginOf(s.location) + "-" + Locations.endOf(s.location) + "]");
 973             }
 974             System.out.print(" ");
 975         }
 976         System.out.println("-> " + reduced.getClass().getSimpleName() + " " +
 977                 Locations.beginOf(sym.location) + "-" + Locations.endOf(sym.location));*/
 978     }
 979
 980     @Override
 981     protected RuntimeException syntaxError(Token token, String description) {
 982         throw new SCLSyntaxErrorException(token.location, description);
 983     }
 984
 985     @Override
 986     protected Object reduceIdAccessor() {
 987         return new IdAccessor('.', ((Token)get(0)).text);
 988     }
 989
 990     @Override
 991     protected Object reduceStringAccessor() {
 992         return new StringAccessor('.', ((Token)get(1)).text);
 993     }
 994
 995     @Override
 996     protected Object reduceExpAccessor() {
 997         return new ExpressionAccessor('.', (Expression)get(1));
 998     }
 999
1000     @Override
1001     protected Object reduceFieldAccess() {
1002         if(length() == 1)
1003             return get(0);
1004         Expression result = (Expression)get(0);
1005         for(int i=2;i<length();i+=2) {
1006             FieldAccessor accessor = (FieldAccessor)get(i);
1007             accessor.accessSeparator = ((Token)get(i-1)).text.charAt(0);
1008             result = new EFieldAccess(result, accessor);
1009         }
1010         return result;
1011     }
1012
1013     @Override
1014     protected Object reduceQueryBlock() {
1015         if(length() == 2)
1016             return Query.EMPTY_ARRAY;
1017         Query[] queries = new Query[length()/2];
1018         for(int i=0;i<queries.length;++i)
1019             queries[i] = (Query)get(2*i+1);
1020         return queries;
1021     }
1022
1023     @Override
1024     protected Object reduceGuardQuery() {
1025         return new QPreGuard((Expression)get(0));
1026     }
1027
1028     @Override
1029     protected Object reduceEqualsQuery() {
1030         return new QPreEquals((Expression)get(0), (Expression)get(2));
1031     }
1032
1033     @Override
1034     protected Object reduceBindQuery() {
1035         return new QPreBinds((Expression)get(0), (Expression)get(2));
1036     }
1037
1038     @Override
1039     protected Object reduceCompositeQuery() {
1040         Query[] queries = (Query[])get(1);
1041         switch(((Token)get(0)).text.charAt(1)) {
1042         case '&': return new QConjunction(queries);
1043         case '|': return new QDisjunction(queries);
1044         case '!': return new QNegation(new QConjunction(queries));
1045         case '?': return new QAlternative(queries);
1046         default: throw new InternalCompilerError();
1047         }
1048     }
1049
1050     @Override
1051     protected Object reduceRuleStatement() {
1052         return new RuleStatement((Expression)get(0), new QConjunction((Query[])get(2)));
1053     }
1054
1055     @Override
1056     protected Object reduceHashedId() {
1057         return new EVar("#" + ((Token)get(1)).text);
1058     }
1059
1060     @Override
1061     protected Object reduceStringLiteral() {
1062         int expCount = length()/3;
1063         if(expCount == 0)
1064             return new ELiteral(new StringConstant(((Token)get(1)).text));
1065         else {
1066             String[] strings = new String[expCount+1];
1067             Expression[] expressions = new Expression[expCount];
1068             for(int i=0;i<expCount;++i) {
1069                 strings[i] = ((Token)get(i*3+1)).text;
1070                 expressions[i] = (Expression)get(i*3+2);
1071             }
1072             strings[expCount] = ((Token)get(expCount*3+1)).text;
1073             return new EStringLiteral(strings, expressions);
1074         }
1075     }
1076
1077     @Override
1078     protected Object reduceOneCommand() {
1079         return null;
1080     }
1081
1082     @Override
1083     protected Object reduceManyCommands() {
1084         return null;
1085     }
1086
1087     @Override
1088     protected Object reduceStatementCommand() {
1089         // to be extended in subclasses
1090         return null;
1091     }
1092
1093     @Override
1094     protected Object reduceImportCommand() {
1095         // to be extended in subclasses
1096         return null;
1097     }
1098
1099     @Override
1100     protected Object reduceImportValueItem() {
1101         return new EVar(((Token)get(0)).text);
1102     }
1103
1104     @Override
1105     protected Object reduceImportHiding() {
1106         EVar[] values = new EVar[(length()-2)/2];
1107         for(int i=0;i<values.length;++i)
1108             values[i] = (EVar)get(i*2+2);
1109         return new ImportDeclaration.ImportSpec(true, values);
1110     }
1111
1112     @Override
1113     protected Object reduceImportShowing() {
1114         EVar[] values = new EVar[(length()-1)/2];
1115         for(int i=0;i<values.length;++i)
1116             values[i] = (EVar)get(i*2+1);
1117         return new ImportDeclaration.ImportSpec(false, values);
1118     }
1119
1120     @Override
1121     protected Object reduceRuleDeclarations() {
1122         ArrayList<Object> declarations = new ArrayList<Object>(length()/2);
1123         for(int i=1;i<length();i+=2)
1124             declarations.add((Object)get(i));
1125         return declarations;
1126     }
1127
1128     private static final String[] EMPTY_STRING_ARRAY = new String[0];
1129
1130     @SuppressWarnings("unchecked")
1131     @Override
1132     protected Object reduceRuleDefinition() {
1133         String[] extendsNames = EMPTY_STRING_ARRAY;
1134         if(length() >= 6) {
1135             int extendsCount = (length() - 4) / 2;
1136             extendsNames = new String[extendsCount];
1137             for(int i=0;i<extendsCount;++i)
1138                 extendsNames[i] = ((Token)get(3+i*2)).text;
1139         }
1140
1141         DRuleAst rule = new DRuleAst(
1142                 ((Token)get(0)).id == SCLTerminals.ABSTRACT_RULE,
1143                 ((Token)get(1)).text,
1144                 extendsNames);
1145
1146         ArrayList<Object> ruleDeclarations = (ArrayList<Object>)get(length()-1);
1147         ArrayList<Query> section = null;
1148         for(Object decl : ruleDeclarations) {
1149             if(decl instanceof DAnnotationAst) {
1150                 DAnnotationAst annotation = (DAnnotationAst)decl;
1151                 section = rule.getSection(annotation.id.text.substring(1));
1152             }
1153             else if(decl instanceof Query) {
1154                 if(section == null)
1155                     section = rule.getSection("when");
1156                 section.add((Query)decl);
1157             }
1158             else
1159                 throw new InternalCompilerError();
1160         }
1161         return rule;
1162     }
1163
1164     @Override
1165     protected Object reduceQueryRuleDeclaration() {
1166         return get(0);
1167     }
1168
1169     @Override
1170     protected Object reduceMappingRelationDefinition() {
1171         TypeAst[] types = new TypeAst[length()-2];
1172         for(int i=0;i<types.length;++i)
1173             types[i] = (TypeAst)get(i+2);
1174         return new DMappingRelationAst(
1175                 ((Token)get(1)).text,
1176                 types);
1177     }
1178
1179     @Override
1180     protected Object reduceTransformation() {
1181         return new ETransformation(
1182                 ((Token)get(1)).text,
1183                 new QConjunction((Query[])get(3))
1184                 );
1185     }
1186
1187     @SuppressWarnings("unchecked")
1188     @Override
1189     protected Object reduceRelationDefinition() {
1190         return new DRelationAst((Expression)get(0),
1191                 ((ArrayList<Object>)get(2)).toArray());
1192     }
1193
1194     @Override
1195     protected Object reduceRecord() {
1196         FieldAssignment[] fields = new FieldAssignment[length()/2-1];
1197         for(int i=0;i<fields.length;++i)
1198             fields[i] = (FieldAssignment)get(2+i*2);
1199         return new ERecord(new EVar((Token)get(0)), fields);
1200     }
1201
1202     @Override
1203     protected Object reduceField() {
1204         return new FieldAssignment(((Token)get(0)).text, (Expression)get(2));
1205     }
1206
1207     @Override
1208     protected Object reduceFieldShorthand() {
1209         return new FieldAssignment(((Token)get(0)).text, null);
1210     }
1211
1212     @Override
1213     protected Object reduceRecordConstructor() {
1214         int idPos;
1215         for(idPos=0;idPos<length();idPos+=2)
1216             if(((Token)get(idPos)).id == SCLTerminals.ID)
1217                 break;
1218         DAnnotationAst[] annotations = idPos == 0 ? DAnnotationAst.EMPTY_ARRAY : new DAnnotationAst[idPos/2];
1219         for(int i=0;i<idPos/2;++i)
1220             annotations[i] = new DAnnotationAst((Token)get(i*2),
1221                     Arrays.asList((Expression)get(i*2+1)));
1222         TypeAst[] parameters = new TypeAst[(length()-idPos-1)/2];
1223         String[] fieldNames = new String[parameters.length];
1224         for(int i=0;i<parameters.length;++i) {
1225             FieldDescription fieldDesc = (FieldDescription)get(idPos+(i+1)*2);
1226             parameters[i] = fieldDesc.type;
1227             fieldNames[i] = fieldDesc.name;
1228         }
1229         return new ConstructorAst(annotations, (Token)get(idPos), parameters, fieldNames);
1230     }
1231
1232     @Override
1233     protected Object reduceFieldDescription() {
1234         return new FieldDescription(((Token)get(0)).text, (TypeAst)get(2));
1235     }
1236
1237     @Override
1238     protected Object reduceEq() {
1239         return (Expression)get(2);
1240     }
1241
1242     @Override
1243     protected Object reduceEquationBlock() {
1244         if(length() == 0)
1245             return new EEquations(Equation.EMPTY_ARRAY);
1246         Equation[] equations = new Equation[length()/2+1];
1247         for(int i=0;i<equations.length;++i)
1248             equations[i] = (Equation)get(2*i);
1249         return new EEquations(equations);
1250     }
1251
1252     @Override
1253     protected Object reduceGuardEquation() {
1254         return new EqGuard((Expression)get(0));
1255     }
1256
1257     @Override
1258     protected Object reduceBasicEquation() {
1259         return new EqBasic((Expression)get(0), (Expression)get(2));
1260     }
1261
1262     @Override
1263     protected Object reduceViewPattern() {
1264         return new EViewPattern((Expression)get(1), (Expression)get(3));
1265     }
1266
1267     @Override
1268     protected Object reduceConstraintStatement() {
1269         ConstructorAst constructor = (ConstructorAst)get(1);
1270         return new ConstraintStatement(constructor.name, constructor.parameters, constructor.fieldNames, constructor.annotations);
1271     }
1272
1273     /*
1274     @Override
1275     protected Object reduceWhen() {
1276         return new EWhen(
1277                 new QConjunction((Query[])get(1)),
1278                 (Expression)get(3));
1279     }*/
1280
1281     @Override
1282     protected Object reduceDummy() {
1283         throw new UnsupportedOperationException();
1284     }
1285
1286     @Override
1287     protected Object reduceRulesetDefinition() {
1288         Token name = (Token)get(1);
1289         EBlock block = (EBlock)get(3);
1290         return new DRulesetAst(name.text, block);
1291     }
1292
1293     @Override
1294     protected Object reduceLocalInclude() {
1295         Token name = (Token)get(1);
1296         Expression value = (Expression)get(2);
1297         return new IncludeStatement(name, value);
1298     }
1299
1300     /*@Override
1301     protected Object reduceConstraintSpec() {
1302         Expression[] expressions = new Expression[length()/2-1];
1303         for(int i=0;i<expressions.length;++i)
1304             expressions[i] = (Expression)get(2*i+1);
1305         return expressions;
1306     }*/
1307
1308     @Override
1309     protected Object reduceCHRSelect() {
1310         return new EPreCHRSelect((CHRAstQuery)get(3), (Expression)get(1));
1311     }
1312
1313     @Override
1314     protected Object reduceCHRAtom() {
1315         return CHRAstAtom.atom((Expression)get(0));
1316     }
1317
1318     @Override
1319     protected Object reduceCHREquals() {
1320         return new CHRAstEquals((Expression)get(0), (Expression)get(2));
1321     }
1322
1323     @Override
1324     protected Object reduceCHRBinds() {
1325         return new CHRAstBinds((Expression)get(0), (Expression)get(2));
1326     }
1327
1328     @Override
1329     protected Object reduceCHRConjunction() {
1330         CHRAstQuery[] conjuncts = new CHRAstQuery[(length()+1)/2];
1331         for(int i=0;i<conjuncts.length;++i)
1332             conjuncts[i] = (CHRAstQuery)get(i*2);
1333         return CHRAstConjunction.conjunction(conjuncts);
1334     }
1335
1336     @Override
1337     protected Object reduceVerboseCHRConjunction() {
1338         CHRAstQuery[] conjuncts = new CHRAstQuery[(length()-1)/2];
1339         for(int i=0;i<conjuncts.length;++i)
1340             conjuncts[i] = (CHRAstQuery)get(i*2+1);
1341         return CHRAstConjunction.conjunction(conjuncts);
1342     }
1343
1344     @Override
1345     protected Object reduceVerboseCHRStatement() {
1346         return new CHRStatement((CHRAstQuery)get(1), (CHRAstQuery)get(3));
1347     }
1348
1349     @Override
1350     protected Object reduceCHRStatement() {
1351         return new CHRStatement((CHRAstQuery)get(0), (CHRAstQuery)get(2));
1352     }
1353
1354     @Override
1355     protected Object reduceWildcard() {
1356         return new FieldAssignment(FieldAssignment.WILDCARD, null);
1357     }
1358
1359 }