Java 类org.antlr.v4.runtime.tree.RuleNode 实例源码

private void enterParseTree(ParseTree tree){
    int cc = tree.getChildCount();
    for(int i=0;i<cc;i++){
        ParseTree c = tree.getChild(i);
        if(c instanceof RuleNode){
            enterParseTree(c);
        }else if (c instanceof TerminalNode){
            Token t = ((TerminalNode)c).getSymbol();
            index2token.put(tokenCounter, t);
            token2tree.put(t, c);
            tokenCounter ++;
        }else{
            System.err.println("unknown node:" + c);
        }
    }
}

@SuppressWarnings("unchecked")
@Override
public Object visitChildren(final RuleNode node) {

    final int n = node.getChildCount();

    for (int i = 0; i < n; i++) {
        final ParseTree c = node.getChild(i);
        c.accept(this);

    }
    final String textToFind = node.getText();
    if (StringUtils.containsIgnoreCase(textToFind, tempText)
            || StringUtils.containsIgnoreCase(tempText, textToFind)) {
        nodes.add(new ParsedNode(node));
    }
    return null;

}

protected void interpretVariable(ParseTree tree) {
    String          varName  = null;
    Set<PQLTask>    varValue = null;

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i);

        if(child instanceof RuleNode) {
               int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

               switch (ruleIndex) {
                case PQLParser.RULE_varName:
                    varName = interpretName(child);
                    break;
                case PQLParser.RULE_setOfTasks:
                    varValue = interpretSetOfTasks(child);
                    break;
               }
           }
       }

    this.variables.put(varName,varValue);
}

protected void interpretAttribute(ParseTree tree) {
    ParseTree child = tree.getChild(0); 

    if (child instanceof RuleNode) {
           int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

           switch (ruleIndex) {
            case PQLParser.RULE_universe :
                this.attributes.add(new PQLAttribute());
                break;
            case PQLParser.RULE_attributeName :
                this.attributes.add(new PQLAttribute(this.interpretString(child)));
                break;
           }
       }
}

protected void interpretLocation(ParseTree tree) {  
    ParseTree child = tree.getChild(0); 

    if (child instanceof RuleNode) {
           int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

           switch (ruleIndex) {
            case PQLParser.RULE_universe :
                this.locations.add(new PQLLocation());
                break;
            case PQLParser.RULE_locationPath :
                this.locations.add(new PQLLocation(this.interpretString(child)));
                break;
           }
       }
}

protected boolean interpretPredicate(ParseTree tree) {
    if (tree==null) return true; // WHERE clause is not specified for this query!

    boolean result = false;

    ParseTree child = tree.getChild(0); 
    int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

    switch (ruleIndex) {
        case PQLParser.RULE_proposition:
            result = interpretProposition(child);
            break;
        case PQLParser.RULE_conjunction:
            result = interpretConjunction(child);
            break;
        case PQLParser.RULE_disjunction:
            result = interpretDisjunction(child);
            break;
        case PQLParser.RULE_logicalTest:
            result = interpretLogicalTest(child);
            break;
    }

    return result;
}

protected boolean interpretSetComparison(ParseTree tree) {      
    Set<PQLTask> A = interpretSetOfTasks(tree.getChild(0));
    Set<PQLTask> B = interpretSetOfTasks(tree.getChild(2));

    ParseTree child = tree.getChild(1).getChild(0);
    int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

    switch (ruleIndex) {
        case PQLParser.RULE_identical:
            return A.equals(B) ? true : false;
        case PQLParser.RULE_different:
            return A.equals(B) ? false : true;
        case PQLParser.RULE_overlapsWith:
            for (PQLTask task : A) 
                if (B.contains(task)) return true;

            return false;
        case PQLParser.RULE_subsetOf:
            return B.containsAll(A) ? true : false;
        case PQLParser.RULE_properSubsetOf:
            return B.containsAll(A) && !A.equals(B) ? true : false;
    }

    return false;
}

protected PQLTask interpretTask(ParseTree tree) {
    String label = "";
    double similarity = 1.0;

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i);

        if (child instanceof RuleNode) {
            int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

               switch (ruleIndex) {
                case PQLParser.RULE_approximate:
                    similarity = labelMngr.getDefaultLabelSimilarityThreshold();
                    break;
                case PQLParser.RULE_label:
                    label = this.interpretLabel(child);
                    break;
                case PQLParser.RULE_similarity:
                    similarity = this.interpretSimilarity(child);
                    break;
               }
           }
       }

    return new PQLTask(label, similarity);
}

protected PQLTrace interpretInsertTrace(ParseTree tree) {
    PQLTrace trace = new PQLTrace();

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i).getChild(0); //getting a task or '*'

        if(child instanceof RuleNode) {
            int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

            if (ruleIndex == PQLParser.RULE_task) { //is task 
                trace.addTask(this.interpretTask(child));
            }
            else { // is '*'
                trace.addTask(this.interpretTraceUniverse());
                trace.setHasAsterisk(true);
            } 
        }
    }

    return trace;

}

protected boolean interpretParentheses(ParseTree tree) {
    ParseTree child = tree.getChild(1); 
    int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

    switch (ruleIndex) {
        case PQLParser.RULE_proposition:
            return interpretProposition(child);
        case PQLParser.RULE_conjunction:
            return interpretConjunction(child);
        case PQLParser.RULE_disjunction:
            return interpretDisjunction(child);
        case PQLParser.RULE_logicalTest:
            return interpretLogicalTest(child);
    }

    return false;
}

protected boolean interpretLogicalTest(ParseTree tree) {
    ParseTree child = tree.getChild(0); 
    int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

    switch (ruleIndex) {
        case PQLParser.RULE_isTrue:
            return interpretLogicalTest(child,true,true);
        case PQLParser.RULE_isNotTrue:
            return interpretLogicalTest(child,false,true);
        case PQLParser.RULE_isFalse:
            return interpretLogicalTest(child,true,false);
        case PQLParser.RULE_isNotFalse:
            return interpretLogicalTest(child,false,false);
    }

    return false;
}

protected Set<PQLTask> interpretSetOfTasks(ParseTree tree) {        
    ParseTree child = tree.getChild(0); 
    int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

    switch (ruleIndex) {
        case PQLParser.RULE_tasks:
            return interpretTasks(child);
        case PQLParser.RULE_union:
            return interpretUnion(child);
        case PQLParser.RULE_difference:
            return interpretDifference(child);
        case PQLParser.RULE_intersection:
            return interpretIntersection(child);
    }

    return new HashSet<PQLTask>();
}

protected Set<PQLTask> interpretTasks(ParseTree tree) {
    ParseTree child = tree.getChild(0);

    if (child instanceof RuleNode) {
        int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

        switch (ruleIndex) {
            case PQLParser.RULE_varName:
                return this.interpretVarNameSetOfTasks(child);
            case PQLParser.RULE_setOfAllTasks:
                return this.interpretSetOfAllTasks(child);
            case PQLParser.RULE_setOfTasksLiteral:
                return interpretSetOfTasksLiteral(child);
            case PQLParser.RULE_setOfTasksConstruction:
                return interpretSetOfTasksConstruction(child);
            case PQLParser.RULE_setOfTasksParentheses:
                return interpretSetOfTasksParentheses(child);
        }   
    }

    return new HashSet<PQLTask>();
}

protected Set<PQLTask> interpretSetOfTasksConstruction(ParseTree tree) {
    ParseTree child = tree.getChild(0);

    if (child instanceof RuleNode) {
        int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

        switch (ruleIndex) {
            case PQLParser.RULE_unaryPredicateConstruction:
                return interpretUnaryPredicateConstruction(child);
            case PQLParser.RULE_binaryPredicateConstruction:
                return interpretBinaryPredicateConstruction(child);
        }   
    }

    return new HashSet<PQLTask>();
}

protected Set<PQLTask> interpretSetOfTasksLiteral(ParseTree tree) {
    Set<PQLTask> result = new HashSet<PQLTask>();

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i);

        if(child instanceof RuleNode) {
            int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

            if (ruleIndex == PQLParser.RULE_task) {
                result.add(this.interpretTask(child));
            }
        }
    }

    return result;
}

protected Set<PQLTask> interpretUnion(ParseTree tree) {
    Set<PQLTask> result = new HashSet<PQLTask>();

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i);

        if(child instanceof RuleNode) {
               int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

               switch (ruleIndex) {
                case PQLParser.RULE_tasks:
                    result.addAll(interpretTasks(child));
                    break;
                case PQLParser.RULE_difference:
                    result.addAll(interpretDifference(child));
                    break;
                case PQLParser.RULE_intersection:
                    result.addAll(interpretIntersection(child));
                    break; 
               }
           }
       }

    return result;
}

protected Set<PQLTask> interpretIntersection(ParseTree tree) {
    Set<PQLTask> result = null;

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i);

        if(child instanceof RuleNode) {
               int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

               switch (ruleIndex) {
                case PQLParser.RULE_tasks:
                    if (result==null) result = this.interpretTasks(child);
                    else result.retainAll(this.interpretTasks(child));
                    break;
                case PQLParser.RULE_difference:
                    if (result==null) result = this.interpretDifference(child);
                    else result.retainAll(this.interpretDifference(child));
                    break;
               }
           }
       }

    return result;
}

protected Set<PQLTask> interpretDifference(ParseTree tree) {
    ParseTree child = tree.getChild(2);
    int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

    Set<PQLTask> set1 = this.interpretTasks(tree.getChild(0));
    Set<PQLTask> set2 = new HashSet<PQLTask>();

    switch (ruleIndex) {
        case PQLParser.RULE_tasks:
            set2 = interpretTasks(child);
            break;
        case PQLParser.RULE_difference:
            set2 = interpretDifference(child);
            break;
       }

    set1.removeAll(set2);

    return set1;
}

protected boolean interpretDisjunction(ParseTree tree) {
    boolean result = false;

    for (int i = 0; i < tree.getChildCount(); i++) {
        ParseTree child = tree.getChild(i);

        if(child instanceof RuleNode) {
               int ruleIndex = ((RuleNode)child).getRuleContext().getRuleIndex();

               switch (ruleIndex) {
                case PQLParser.RULE_proposition:
                    result |= interpretProposition(child);
                    break;
                case PQLParser.RULE_logicalTest:
                    result |= interpretLogicalTest(child);
                    break;
            }

               if (result==true) return result;
           }
       }

    return result;
}

public void testGetPropertyName() throws Exception {
    final String PROPERTY = "a('aa').b[1].c";

    // Should parse and result in the exact same property name
    Pair<Tree, CommonTokenStream> parsed = SupportParserHelper.parseEventProperty(PROPERTY);
    Tree propertyNameExprNode = parsed.getFirst().getChild(0);
    ASTUtil.dumpAST(propertyNameExprNode);
    String propertyName = ((RuleNode) propertyNameExprNode).getText();
    assertEquals(PROPERTY, propertyName);

    // Try AST with tokens separated, same property name
    parsed = SupportParserHelper.parseEventProperty("a(    'aa'   ). b [ 1 ] . c");
    propertyNameExprNode = parsed.getFirst().getChild(0);
    propertyName = ((RuleNode) propertyNameExprNode).getText();
    assertEquals(PROPERTY, propertyName);
}

public void walk(ParseTreeListener listener, ParseTree t) {
    if ( t instanceof ErrorNode) {
        listener.visitErrorNode((ErrorNode)t);
        return;
    }
    else if ( t instanceof TerminalNode) {
        listener.visitTerminal((TerminalNode)t);
        return;
    }
    RuleNode r = (RuleNode)t;
    enterRule(listener, r);
    int n = r.getChildCount();
    for (int i = 0; i<n; i++) {
        walk(listener, r.getChild(i));
    }
    exitRule(listener, r);

}

@Override
public ParseTree visit(ParseTree node) {
    ParseTree result = null;

    if (!this.match) {
        if (matches(node, this.currentSelector)) {
            if (this.iterator.hasNext()) {
                this.currentSelector = this.iterator.next();
                result = super.visit(node);
            } else if (focusNode.equals(node)) {
                match = true;
            }
        } else if (node.getChildCount() > 0) {
            if (!this.match) {
                result = super.visitChildren((RuleNode) node);
            }
        }
    }
    return result;
}

public String visitChildren(RuleNode node) {
int n = node.getChildCount();
if (n > 1) {
    StringBuilder result = new StringBuilder();
    ParseTree child;
    String childResult;
    for (int i = 0; i < n; i++) {
    child = node.getChild(i);
    childResult = child.accept(this);
    if (childResult != null) {
        if (i > 0) {
        result.append(' ');
        }
        result.append(childResult);
    }
    }
    return result.toString();
} else {
    if (n == 1) {
    return node.getChild(0).accept(this);
    } else {
    return node.getText();
    }
}
   }

public List<String> visitChildren(RuleNode node) {
List<String> result = defaultResult();
List<String> childResult;
ParseTree child;
int n = node.getChildCount();
for (int i = 0; i < n; i++) {
    if (!shouldVisitNextChild(node, result)) {
    break;
    }

    child = node.getChild(i);
    childResult = child.accept(this);
    if (childResult != null) {
    if (result != null) {
        result.addAll(childResult);
    } else {
        result = childResult;
    }
    }
}
return result;
   }

@Override
@RuleDependencies({
    @RuleDependency(recognizer=GrammarParser.class, rule=GrammarParser.RULE_modeSpec, version=3, dependents=Dependents.PARENTS),
    @RuleDependency(recognizer=GrammarParser.class, rule=GrammarParser.RULE_ruleSpec, version=3, dependents=Dependents.PARENTS),
})
public Tuple2<? extends ParseTree, Integer> visitModeSpec(ModeSpecContext ctx) {
    // use the preceeding rule (if any), otherwise relative to mode
    for (int i = priorSiblings.size() - 2; i >= 0; i--) {
        ParseTree sibling = priorSiblings.get(i);
        if (!(sibling instanceof RuleNode)) {
            continue;
        }

        RuleContext context = ((RuleNode)sibling).getRuleContext();
        if (context.getRuleIndex() == GrammarParser.RULE_ruleSpec) {
            return Tuple.create(context, 0);
        }
    }

    return Tuple.create(ctx, getCodeStyle().getIndentSize());
}

public static Interval getSourceInterval(@NonNull ParseTree context) {
    Parameters.notNull("context", context);

    if (context instanceof TerminalNode) {
        TerminalNode terminalNode = (TerminalNode)context;
        Token token = terminalNode.getSymbol();
        return new Interval(token.getStartIndex(), token.getStopIndex());
    } else if (context instanceof RuleNode) {
        RuleNode ruleNode = (RuleNode)context;
        RuleContext ruleContext = ruleNode.getRuleContext();
        if (ruleContext instanceof ParserRuleContext) {
            return getSourceInterval((ParserRuleContext)ruleContext);
        } else {
            Token startSymbol = getStartSymbol(context);
            Token stopSymbol = getStopSymbol(context);
            if (startSymbol == null || stopSymbol == null) {
                return Interval.INVALID;
            }

            return new Interval(startSymbol.getStartIndex(), stopSymbol.getStopIndex());
        }
    } else {
        return Interval.INVALID;
    }
}

public static Token getStartSymbol(ParseTree context) {
    TerminalNode node = getStartNode(context);
    if (node != null) {
        return node.getSymbol();
    }

    if (!(context instanceof RuleNode)) {
        return null;
    }

    RuleContext ruleContext = ((RuleNode)context).getRuleContext();
    if (ruleContext instanceof ParserRuleContext) {
        return ((ParserRuleContext)ruleContext).getStart();
    }

    return null;
}

@CheckForNull
public static RuleNode findAncestor(@NonNull ParseTree tree, @NonNull BitSet ruleIndexes) {
    for (ParseTree current = tree; current != null; current = current.getParent()) {
        if (!(current instanceof RuleNode)) {
            continue;
        }

        RuleNode ruleNode = (RuleNode)current;
        int ruleIndex = ruleNode.getRuleContext().getRuleIndex();
        if (ruleIndex < 0) {
            continue;
        }

        if (ruleIndexes.get(ruleIndex)) {
            return ruleNode;
        }
    }

    return null;
}

@CheckForNull
public static <ContextClass> ContextClass findAncestor(@NonNull ParseTree tree, @NonNull Class<ContextClass> nodeType) {
    for (ParseTree current = tree; current != null; current = current.getParent()) {
        if (!(current instanceof RuleNode)) {
            continue;
        }

        RuleNode ruleNode = (RuleNode)current;
        RuleContext ruleContext = ruleNode.getRuleContext();
        if (nodeType.isInstance(ruleContext)) {
            return nodeType.cast(ruleContext);
        }
    }

    return null;
}

private String getNodeText(@NotNull final Tree t, @Nullable final List<String> ruleNames) {
  if (ruleNames != null) {
    if (t instanceof RuleNode) {
      int ruleIndex = ((RuleNode) t).getRuleContext().getRuleIndex();
      String ruleName = ruleNames.get(ruleIndex);
      return ruleName;
    }
    else if (t instanceof ErrorNode) {
      return "<" + t.toString() + ">";
    }
    else if (t instanceof TerminalNode) {
      Token symbol = ((TerminalNode) t).getSymbol();
      if (symbol != null) {
        String s = symbol.getText();
        return "'" + s + "'";
      }
    }
  }
  // no recog for rule names
  Object payload = t.getPayload();
  if (payload instanceof Token) {
    return ((Token) payload).getText();
  }
  return t.getPayload().toString();
}

public static String getNodeText(Tree t, String[] ruleNames, String[] tokenNames) {
    if (ruleNames != null) {
        if (t instanceof RuleNode) {
            int ruleIndex = ((RuleNode) t).getRuleContext().getRuleIndex();
            return ruleNames[ruleIndex];
        } else if (t instanceof ErrorNode) {
            return t.toString();
        } else if (t instanceof TerminalNode) {
            Token symbol = ((TerminalNode) t).getSymbol();
            if (symbol != null) {
                return "'" + symbol.getText() + "'";
            }
        }
    }
    // no recog for rule names
    Object payload = t.getPayload();
    if (payload instanceof Token) {
        return ((Token) payload).getText();
    }
    return t.getPayload().toString();
}

@Override
public Integer visitChildren(RuleNode arg0) {
    int iHash = 1;
    boolean bVisit = false;

    for (int i = arg0.getChildCount() - 1; i >= 0; i--) {
        Integer iVisit = visit(arg0.getChild(i));

        // If the visit resulted no hash ignore the hash.
        if (iVisit != null) {
            iHash = iHash * PRIME + iVisit;
            bVisit = true;
        }
    }

    if (bVisit) {
        return iHash;
    } else {
        return defaultResult(); // No result.
    }
}

@Override
@RuleDependencies({
    @RuleDependency(recognizer=GrammarParser.class, rule=GrammarParser.RULE_modeSpec, version=3, dependents=Dependents.PARENTS),
    @RuleDependency(recognizer=GrammarParser.class, rule=GrammarParser.RULE_ruleSpec, version=3, dependents=Dependents.PARENTS),
})
public Tuple2<? extends ParseTree, Integer> visitModeSpec(ModeSpecContext ctx) {
    // use the preceeding rule (if any), otherwise relative to mode
    for (int i = priorSiblings.size() - 2; i >= 0; i--) {
        ParseTree sibling = priorSiblings.get(i);
        if (!(sibling instanceof RuleNode)) {
            continue;
        }

        RuleContext context = ((RuleNode)sibling).getRuleContext();
        if (context.getRuleIndex() == GrammarParser.RULE_ruleSpec) {
            return Tuple.create(context, 0);
        }
    }

    return Tuple.create(ctx, getCodeStyle().getIndentSize());
}

public static Interval getSourceInterval(@NonNull ParseTree context) {
    Parameters.notNull("context", context);

    if (context instanceof TerminalNode) {
        TerminalNode terminalNode = (TerminalNode)context;
        Token token = terminalNode.getSymbol();
        return new Interval(token.getStartIndex(), token.getStopIndex());
    } else if (context instanceof RuleNode) {
        RuleNode ruleNode = (RuleNode)context;
        RuleContext ruleContext = ruleNode.getRuleContext();
        if (ruleContext instanceof ParserRuleContext) {
            return getSourceInterval((ParserRuleContext)ruleContext);
        } else {
            Token startSymbol = getStartSymbol(context);
            Token stopSymbol = getStopSymbol(context);
            if (startSymbol == null || stopSymbol == null) {
                return Interval.INVALID;
            }

            return new Interval(startSymbol.getStartIndex(), stopSymbol.getStopIndex());
        }
    } else {
        return Interval.INVALID;
    }
}

public static Token getStartSymbol(ParseTree context) {
    TerminalNode node = getStartNode(context);
    if (node != null) {
        return node.getSymbol();
    }

    if (!(context instanceof RuleNode)) {
        return null;
    }

    RuleContext ruleContext = ((RuleNode)context).getRuleContext();
    if (ruleContext instanceof ParserRuleContext) {
        return ((ParserRuleContext)ruleContext).getStart();
    }

    return null;
}

@CheckForNull
public static RuleNode findAncestor(@NonNull ParseTree tree, @NonNull BitSet ruleIndexes) {
    for (ParseTree current = tree; current != null; current = current.getParent()) {
        if (!(current instanceof RuleNode)) {
            continue;
        }

        RuleNode ruleNode = (RuleNode)current;
        int ruleIndex = ruleNode.getRuleContext().getRuleIndex();
        if (ruleIndex < 0) {
            continue;
        }

        if (ruleIndexes.get(ruleIndex)) {
            return ruleNode;
        }
    }

    return null;
}

@CheckForNull
public static <ContextClass> ContextClass findAncestor(@NonNull ParseTree tree, @NonNull Class<ContextClass> nodeType) {
    for (ParseTree current = tree; current != null; current = current.getParent()) {
        if (!(current instanceof RuleNode)) {
            continue;
        }

        RuleNode ruleNode = (RuleNode)current;
        RuleContext ruleContext = ruleNode.getRuleContext();
        if (nodeType.isInstance(ruleContext)) {
            return nodeType.cast(ruleContext);
        }
    }

    return null;
}

public final SubPath propertyOrKey(String string) {
    checkNotNull(string);
    try {
        return newParser(string, true).parseProperty().accept(new PropertyPathBaseVisitor<SubPath>() {

            @Override
            public SubPath visitProperty(PropertyPathParser.PropertyContext ctx) {
                return new Property(PropertyPath.this, ctx.getText());
            }

            @Override
            protected boolean shouldVisitNextChild(RuleNode node, SubPath currentResult) {
                return currentResult == null;
            }

        });
    } catch (SilentParseException e) {
        return new Key(this, string);
    }
}

public String visitChildren(RuleNode node, List<Integer> withoutNodes) {
    if(node == null) return "";
    String result = this.defaultResult();
    int n = node.getChildCount();

    for(int i = 0; i < n && this.shouldVisitNextChild(node, result); ++i) {
        if(withoutNodes != null && withoutNodes.contains(i)) continue;
        ParseTree c = node.getChild(i);
        String childResult = c instanceof TerminalNode ? printTerminalNode((TerminalNode) c) : c.accept(this);
        result = this.aggregateResult(result, childResult);
    }

    return result;
}

public String visitWithoutTerminals(RuleNode node) {
    String result = this.defaultResult();
    int n = node.getChildCount();

    for(int i = 0; i < n && this.shouldVisitNextChild(node, result); ++i) {
        ParseTree c = node.getChild(i);
        if(c instanceof TerminalNode) continue;
        String childResult = c.accept(this);
        result = this.aggregateResult(result, childResult);
    }

    return result;
}