plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/internal/javascript/ti/TypeInferencerVisitor.java

/*******************************************************************************
 * Copyright (c) 2010 xored software, Inc.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.internal.javascript.ti;

import static org.eclipse.dltk.javascript.typeinfo.ITypeNames.BOOLEAN;
import static org.eclipse.dltk.javascript.typeinfo.ITypeNames.NUMBER;
import static org.eclipse.dltk.javascript.typeinfo.ITypeNames.OBJECT;
import static org.eclipse.dltk.javascript.typeinfo.ITypeNames.STRING;

import java.io.StringReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Stack;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.eclipse.dltk.ast.ASTNode;
import org.eclipse.dltk.compiler.problem.IProblemCategory;
import org.eclipse.dltk.compiler.problem.IProblemIdentifier;
import org.eclipse.dltk.internal.javascript.validation.JavaScriptValidations;
import org.eclipse.dltk.internal.javascript.validation.ValidationMessages;
import org.eclipse.dltk.javascript.ast.ArrayInitializer;
import org.eclipse.dltk.javascript.ast.AsteriskExpression;
import org.eclipse.dltk.javascript.ast.BinaryOperation;
import org.eclipse.dltk.javascript.ast.BooleanLiteral;
import org.eclipse.dltk.javascript.ast.BreakStatement;
import org.eclipse.dltk.javascript.ast.CallExpression;
import org.eclipse.dltk.javascript.ast.CaseClause;
import org.eclipse.dltk.javascript.ast.CatchClause;
import org.eclipse.dltk.javascript.ast.CommaExpression;
import org.eclipse.dltk.javascript.ast.ConditionalOperator;
import org.eclipse.dltk.javascript.ast.ConstStatement;
import org.eclipse.dltk.javascript.ast.ContinueStatement;
import org.eclipse.dltk.javascript.ast.DecimalLiteral;
import org.eclipse.dltk.javascript.ast.DefaultXmlNamespaceStatement;
import org.eclipse.dltk.javascript.ast.DoWhileStatement;
import org.eclipse.dltk.javascript.ast.EmptyExpression;
import org.eclipse.dltk.javascript.ast.EmptyStatement;
import org.eclipse.dltk.javascript.ast.Expression;
import org.eclipse.dltk.javascript.ast.ForEachInStatement;
import org.eclipse.dltk.javascript.ast.ForInStatement;
import org.eclipse.dltk.javascript.ast.ForStatement;
import org.eclipse.dltk.javascript.ast.FunctionStatement;
import org.eclipse.dltk.javascript.ast.GetAllChildrenExpression;
import org.eclipse.dltk.javascript.ast.GetArrayItemExpression;
import org.eclipse.dltk.javascript.ast.GetLocalNameExpression;
import org.eclipse.dltk.javascript.ast.Identifier;
import org.eclipse.dltk.javascript.ast.IfStatement;
import org.eclipse.dltk.javascript.ast.JSDeclaration;
import org.eclipse.dltk.javascript.ast.JSScope;
import org.eclipse.dltk.javascript.ast.LabelledStatement;
import org.eclipse.dltk.javascript.ast.NewExpression;
import org.eclipse.dltk.javascript.ast.NullExpression;
import org.eclipse.dltk.javascript.ast.ObjectInitializer;
import org.eclipse.dltk.javascript.ast.ObjectInitializerPart;
import org.eclipse.dltk.javascript.ast.ParenthesizedExpression;
import org.eclipse.dltk.javascript.ast.PropertyExpression;
import org.eclipse.dltk.javascript.ast.PropertyInitializer;
import org.eclipse.dltk.javascript.ast.RegExpLiteral;
import org.eclipse.dltk.javascript.ast.ReturnStatement;
import org.eclipse.dltk.javascript.ast.Script;
import org.eclipse.dltk.javascript.ast.Statement;
import org.eclipse.dltk.javascript.ast.StatementBlock;
import org.eclipse.dltk.javascript.ast.StringLiteral;
import org.eclipse.dltk.javascript.ast.SwitchComponent;
import org.eclipse.dltk.javascript.ast.SwitchStatement;
import org.eclipse.dltk.javascript.ast.ThisExpression;
import org.eclipse.dltk.javascript.ast.ThrowStatement;
import org.eclipse.dltk.javascript.ast.TryStatement;
import org.eclipse.dltk.javascript.ast.UnaryOperation;
import org.eclipse.dltk.javascript.ast.VariableDeclaration;
import org.eclipse.dltk.javascript.ast.VariableStatement;
import org.eclipse.dltk.javascript.ast.VoidExpression;
import org.eclipse.dltk.javascript.ast.WhileStatement;
import org.eclipse.dltk.javascript.ast.WithStatement;
import org.eclipse.dltk.javascript.ast.XmlAttributeIdentifier;
import org.eclipse.dltk.javascript.ast.XmlExpressionFragment;
import org.eclipse.dltk.javascript.ast.XmlFragment;
import org.eclipse.dltk.javascript.ast.XmlLiteral;
import org.eclipse.dltk.javascript.ast.XmlTextFragment;
import org.eclipse.dltk.javascript.ast.YieldOperator;
import org.eclipse.dltk.javascript.core.JavaScriptProblems;
import org.eclipse.dltk.javascript.parser.JSParser;
import org.eclipse.dltk.javascript.parser.PropertyExpressionUtils;
import org.eclipse.dltk.javascript.typeinference.IAssignProtection;
import org.eclipse.dltk.javascript.typeinference.IValueCollection;
import org.eclipse.dltk.javascript.typeinference.IValueReference;
import org.eclipse.dltk.javascript.typeinference.ReferenceKind;
import org.eclipse.dltk.javascript.typeinference.ReferenceLocation;
import org.eclipse.dltk.javascript.typeinfo.IMemberEvaluator;
import org.eclipse.dltk.javascript.typeinfo.IModelBuilder;
import org.eclipse.dltk.javascript.typeinfo.IModelBuilder.IParameter;
import org.eclipse.dltk.javascript.typeinfo.IModelBuilder.IVariable;
import org.eclipse.dltk.javascript.typeinfo.IModelBuilderExtension;
import org.eclipse.dltk.javascript.typeinfo.IRAnyType;
import org.eclipse.dltk.javascript.typeinfo.IRArrayType;
import org.eclipse.dltk.javascript.typeinfo.IRClassType;
import org.eclipse.dltk.javascript.typeinfo.IRMapType;
import org.eclipse.dltk.javascript.typeinfo.IRNoneType;
import org.eclipse.dltk.javascript.typeinfo.IRSimpleType;
import org.eclipse.dltk.javascript.typeinfo.IRType;
import org.eclipse.dltk.javascript.typeinfo.IRVariable;
import org.eclipse.dltk.javascript.typeinfo.ITypeNames;
import org.eclipse.dltk.javascript.typeinfo.ITypeSystem;
import org.eclipse.dltk.javascript.typeinfo.JSTypeSet;
import org.eclipse.dltk.javascript.typeinfo.RModelBuilder;
import org.eclipse.dltk.javascript.typeinfo.ReferenceSource;
import org.eclipse.dltk.javascript.typeinfo.TypeInfoManager;
import org.eclipse.dltk.javascript.typeinfo.TypeMode;
import org.eclipse.dltk.javascript.typeinfo.TypeUtil;
import org.eclipse.dltk.javascript.typeinfo.model.ArrayType;
import org.eclipse.dltk.javascript.typeinfo.model.FunctionType;
import org.eclipse.dltk.javascript.typeinfo.model.GenericMethod;
import org.eclipse.dltk.javascript.typeinfo.model.JSType;
import org.eclipse.dltk.javascript.typeinfo.model.MapType;
import org.eclipse.dltk.javascript.typeinfo.model.Method;
import org.eclipse.dltk.javascript.typeinfo.model.Parameter;
import org.eclipse.dltk.javascript.typeinfo.model.ParameterizedType;
import org.eclipse.dltk.javascript.typeinfo.model.SimpleType;
import org.eclipse.dltk.javascript.typeinfo.model.Type;
import org.eclipse.dltk.javascript.typeinfo.model.TypeInfoModelFactory;
import org.eclipse.dltk.javascript.typeinfo.model.TypeKind;
import org.eclipse.dltk.javascript.typeinfo.model.TypeVariable;
import org.eclipse.dltk.javascript.typeinfo.model.TypeVariableClassType;
import org.eclipse.dltk.javascript.typeinfo.model.TypeVariableReference;
import org.eclipse.dltk.javascript.typeinfo.model.UnionType;
import org.eclipse.dltk.javascript.typeinfo.model.util.TypeInfoModelSwitch;
import org.eclipse.emf.ecore.EObject;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

public class TypeInferencerVisitor extends TypeInferencerVisitorBase {

	public TypeInferencerVisitor(ITypeInferenceContext context) {
		super(context);
	}

	private final Stack<Branching> branchings = new Stack<Branching>();

	private class Branching {
		public void end() {
			branchings.remove(this);
		}
	}

	protected Branching branching() {
		final Branching branching = new Branching();
		branchings.add(branching);
		return branching;
	}

	public ReferenceSource getSource() {
		final ReferenceSource source = context.getSource();
		return source != null ? source : ReferenceSource.UNKNOWN;
	}

	protected void assign(IValueReference dest, IValueReference src) {
		IRType destType = JavaScriptValidations.typeOf(dest);
		if (destType != null && isXML(destType)) {
			IRType srcType = JavaScriptValidations.typeOf(src);
			if (srcType != null && !isXML(srcType))
				return;
		}
		if (branchings.isEmpty()) {
			dest.setValue(src);
		} else {
			dest.addValue(src, false);
		}
	}

	private static boolean isXML(IRType srcType) {
		return (srcType instanceof IRSimpleType)
				&& (ITypeNames.XML.equals(srcType.getName()) || ITypeNames.XMLLIST
						.equals(srcType.getName()));
	}

	@Override
	public IValueReference visitArrayInitializer(ArrayInitializer node) {
		final JSTypeSet types = JSTypeSet.create();
		for (ASTNode astNode : node.getItems()) {
			if (astNode instanceof StringLiteral) {
				types.add(JSTypeSet.ref(STRING));
			} else if (astNode instanceof DecimalLiteral) {
				types.add(JSTypeSet.ref(NUMBER));
			} else if (astNode instanceof BooleanLiteral) {
				types.add(JSTypeSet.ref(BOOLEAN));
			} else if (astNode instanceof NullExpression
					|| astNode instanceof EmptyExpression) {
				// ignore
			} else {
				final IValueReference child = visit(astNode);
				if (child != null && child.exists()) {
					types.addAll(JavaScriptValidations.getTypes(child));
				}
				// TODO (alex) else add(Obect) ?
			}
		}
		if (types.size() == 1) {
			return context.getFactory().create(peekContext(),
					JSTypeSet.arrayOf(types.getFirst()));
		} else {
			// TODO (alex) if not empty then evaluate common base type.
			return context.getFactory().createArray(peekContext());
		}
	}

	@Override
	public IValueReference visitAsteriskExpression(AsteriskExpression node) {
		return context.getFactory().createXMLList(peekContext());
	}

	@Override
	public IValueReference visitBinaryOperation(BinaryOperation node) {
		final IValueReference left = visit(node.getLeftExpression());
		final int op = node.getOperation();
		if (JSParser.ASSIGN == op) {
			if (left != null) {
				for (IModelBuilder modelBuilder : context.getModelBuilders()) {
					if (modelBuilder instanceof IModelBuilderExtension) {
						((IModelBuilderExtension) modelBuilder)
								.processAssignment(node.getLeftExpression(),
										left);
					}
				}
			}
			if (left != null && left.exists()) {
				left.setAttribute(IReferenceAttributes.RESOLVING, Boolean.TRUE);
				final IValueReference r;
				try {
					r = visit(node.getRightExpression());
				} finally {
					left.setAttribute(IReferenceAttributes.RESOLVING, null);
				}
				return visitAssign(left, r, node);
			} else {
				return visitAssign(left, visit(node.getRightExpression()), node);
			}
		}
		final IValueReference right = visit(node.getRightExpression());
		if (left == null && right instanceof ConstantValue) {
			return right;
		} else if (op == JSParser.LAND) {
			return coalesce(right, left);
		} else if (op == JSParser.GT || op == JSParser.GTE || op == JSParser.LT
				|| op == JSParser.LTE || op == JSParser.NSAME
				|| op == JSParser.SAME || op == JSParser.NEQ
				|| op == JSParser.EQ) {
			return context.getFactory().createBoolean(peekContext());
		} else if (isNumber(left) && isNumber(right)) {
			return context.getFactory().createNumber(peekContext());
		} else if (op == JSParser.ADD) {
			if (isString(left) || isString(right)) {
				return context.getFactory().createString(peekContext());
			}
			return left;
		} else if (JSParser.INSTANCEOF == op) {
			return context.getFactory().createBoolean(peekContext());
		} else if (JSParser.LOR == op) {
			final JSTypeSet typeSet = JSTypeSet.create();
			if (left != null) {
				typeSet.addAll(left.getDeclaredTypes());
				typeSet.addAll(left.getTypes());
			}
			if (right != null) {
				typeSet.addAll(right.getDeclaredTypes());
				typeSet.addAll(right.getTypes());
			}
			return new ConstantValue(typeSet);
		} else {
			// TODO handle other operations
			return null;
		}
	}

	private static IValueReference coalesce(IValueReference v1,
			IValueReference v2) {
		return v1 != null ? v1 : v2;
	}

	private boolean isNumber(IValueReference ref) {
		if (ref != null) {
			final IRType numType = JSTypeSet.ref(NUMBER);
			if (ref.getTypes().contains(numType))
				return true;
			if (numType.equals(ref.getDeclaredType()))
				return true;
		}
		return false;
	}

	private boolean isString(IValueReference ref) {
		if (ref != null) {
			final IRType strType = JSTypeSet.ref(STRING);
			if (ref.getTypes().contains(strType))
				return true;
			if (strType.equals(ref.getDeclaredType()))
				return true;
		}
		return false;
	}

	protected IValueReference visitAssign(IValueReference left,
			IValueReference right, BinaryOperation node) {
		if (left != null) {
			if (node.getLeftExpression() instanceof PropertyExpression) {
				final PropertyExpression property = (PropertyExpression) node
						.getLeftExpression();
				if (property.getObject() instanceof ThisExpression
						&& property.getProperty() instanceof Identifier
						&& !left.exists()) {
					if (isFunctionDeclaration(property))
						left.setKind(ReferenceKind.FUNCTION);
					else
						left.setKind(ReferenceKind.FIELD);
					left.setLocation(ReferenceLocation.create(getSource(),
							property.sourceStart(), property.sourceEnd(),
							property.getProperty().sourceStart(), property
									.getProperty().sourceEnd()));
				}
			}
			if (IValueReference.ARRAY_OP.equals(left.getName())
					&& node.getLeftExpression() instanceof GetArrayItemExpression) {
				GetArrayItemExpression arrayItemExpression = (GetArrayItemExpression) node
						.getLeftExpression();
				IValueReference namedChild = extractNamedChild(
						left.getParent(), arrayItemExpression.getIndex());
				if (namedChild != null) {
					assign(namedChild, right);
				} else {
					assign(left, right);
				}
			} else {
				if (!hasUnknowParentFunctionCall(left))
					assign(left, right);
			}
		}
		return right;
	}

	private boolean hasUnknowParentFunctionCall(IValueReference reference) {
		IValueReference parent = reference.getParent();
		while (parent != null) {
			if (parent.getName().equals(IValueReference.FUNCTION_OP)
					&& !parent.exists())
				return true;
			parent = parent.getParent();
		}
		return false;
	}

	@Override
	public IValueReference visitBooleanLiteral(BooleanLiteral node) {
		return context.getFactory().createBoolean(peekContext());
	}

	@Override
	public IValueReference visitBreakStatement(BreakStatement node) {
		return null;
	}

	@Override
	public IValueReference visitCallExpression(CallExpression node) {
		final IValueReference reference = visit(node.getExpression());
		final List<ASTNode> args = node.getArguments();
		final IValueReference[] arguments = new IValueReference[args.size()];
		for (int i = 0; i < args.size(); ++i) {
			arguments[i] = visit(args.get(i));
		}
		if (reference != null) {
			final List<Method> methods = JavaScriptValidations.extractElements(
					reference, Method.class);
			if (methods != null && methods.size() == 1) {
				if (methods.get(0) instanceof GenericMethod) {
					final GenericMethod method = (GenericMethod) methods.get(0);
					final JSTypeSet type = evaluateGenericCall(method,
							arguments);
					if (type != null) {
						return new ConstantValue(type);
					}
				} else {
					final ITypeSystem typeSystem = getTypeSystemOf(reference);
					final IRType type = JSTypeSet.normalize(typeSystem, methods
							.get(0).getType());
					if (type != null) {
						return new ConstantValue(type);
					} else {
						return null;
					}
				}
			}
			return reference.getChild(IValueReference.FUNCTION_OP);
		} else {
			return null;
		}
	}

	private ITypeSystem getTypeSystemOf(IValueReference reference) {
		final Object value = reference
				.getAttribute(IReferenceAttributes.TYPE_SYSTEM);
		if (value != null) {
			return (ITypeSystem) value;
		}
		return getContext();
	}

	protected JSTypeSet evaluateGenericCall(GenericMethod method,
			IValueReference[] arguments) {
		final JSTypeSet[] argTypes = new JSTypeSet[arguments.length];
		for (int i = 0; i < arguments.length; ++i) {
			argTypes[i] = arguments[i].getDeclaredTypes();
			if (argTypes[i].isEmpty()) {
				argTypes[i] = arguments[i].getTypes();
			}
		}
		// TODO (alex) can be pre-evaluated in GenericParameter objects.
		final boolean genericParams[] = new boolean[method.getParameters()
				.size()];
		for (int i = 0; i < method.getParameters().size(); ++i) {
			genericParams[i] = isGenericType(method.getParameters().get(i)
					.getType());
		}
		final Map<TypeVariable, JSTypeSet> captures = new HashMap<TypeVariable, JSTypeSet>();
		for (TypeVariable variable : method.getTypeParameters()) {
			captures.put(variable, JSTypeSet.create());
		}
		for (int i = 0; i < argTypes.length; ++i) {
			final int index = i < method.getParameters().size() ? i : method
					.getParameters().size() - 1;
			final Parameter parameter = method.getParameters().get(index);
			if (genericParams[index]) {
				final Capture capture = capture(parameter.getType(),
						argTypes[i]);
				if (capture != null) {
					final JSTypeSet captured = captures.get(capture.variable);
					if (captured != null) {
						captured.addAll(capture.types);
					}
				}
			} else {
				// TODO (alex) check parameter compatibility
			}
		}
		if (method.getType() != null) {
			return evaluateReturnType(method.getType(), captures);
		} else {
			return null;
		}
	}

	private JSTypeSet evaluateReturnType(JSType type,
			Map<TypeVariable, JSTypeSet> captures) {
		if (type instanceof TypeVariableReference) {
			final TypeVariable variable = ((TypeVariableReference) type)
					.getVariable();
			return normalizeCapture(captures.get(variable));
		} else if (type instanceof ArrayType) {
			final JSType itemType = ((ArrayType) type).getItemType();
			return JSTypeSet.singleton(JSTypeSet.arrayOf(evaluateReturnType(
					itemType, captures).toRType()));
		} else if (type instanceof ParameterizedType) {
			List<IRType> params = new ArrayList<IRType>();
			final ParameterizedType parameterized = (ParameterizedType) type;
			for (JSType param : parameterized.getActualTypeArguments()) {
				params.add(evaluateReturnType(param, captures).toRType());
			}
			return JSTypeSet.singleton(JSTypeSet.ref(getContext().parameterize(
					parameterized.getTarget(), params)));
		} else if (type instanceof SimpleType) {
			return JSTypeSet.create(JSTypeSet.normalize(getContext(), type));
		} else {
			return JSTypeSet.emptySet();
		}
	}

	private JSTypeSet normalizeCapture(JSTypeSet types) {
		return types;
	}

	private static class Capture {
		final TypeVariable variable;
		final JSTypeSet types;

		public Capture(TypeVariable variable, JSTypeSet types) {
			this.variable = variable;
			this.types = types;
		}
	}

	private Capture capture(JSType paramType, JSTypeSet argTypes) {
		if (paramType instanceof TypeVariableReference) {
			return new Capture(
					((TypeVariableReference) paramType).getVariable(), argTypes);
		} else if (paramType instanceof TypeVariableClassType) {
			final JSTypeSet result = JSTypeSet.create();
			for (IRType type : argTypes) {
				if (type instanceof IRClassType) {
					result.add(((IRClassType) type).toItemType());
				}
			}
			return new Capture(
					((TypeVariableClassType) paramType).getVariable(), result);
		} else {
			// TODO alex other type expressions
			return null;
		}
	}

	private static final TypeInfoModelSwitch<Boolean> GENERIC_TYPE_EXPRESSION = new TypeInfoModelSwitch<Boolean>() {
		@Override
		public Boolean doSwitch(EObject theEObject) {
			return theEObject != null ? super.doSwitch(theEObject) : null;
		}

		@Override
		public Boolean caseJSType(JSType object) {
			return Boolean.FALSE;
		}

		@Override
		public Boolean caseTypeVariableReference(TypeVariableReference object) {
			return Boolean.TRUE;
		}

		public Boolean caseTypeVariableClassType(TypeVariableClassType object) {
			return Boolean.TRUE;
		}

		@Override
		public Boolean caseArrayType(ArrayType object) {
			return doSwitch(object.getItemType());
		}

		@Override
		public Boolean caseMapType(MapType object) {
			final Boolean result = doSwitch(object.getKeyType());
			if (result == Boolean.TRUE) {
				return result;
			}
			return doSwitch(object.getValueType());
		}

		@Override
		public Boolean caseUnionType(UnionType object) {
			for (JSType type : object.getTargets()) {
				final Boolean result = doSwitch(type);
				if (result == Boolean.TRUE) {
					return result;
				}
			}
			return Boolean.FALSE;
		}

		@Override
		public Boolean caseFunctionType(FunctionType object) {
			for (Parameter parameter : object.getParameters()) {
				final Boolean result = doSwitch(parameter.getType());
				if (result == Boolean.TRUE) {
					return result;
				}
			}
			return doSwitch(object.getReturnType());
		}
	};

	private boolean isGenericType(JSType type) {
		if (type != null) {
			final Boolean result = GENERIC_TYPE_EXPRESSION.doSwitch(type);
			return result != null && result.booleanValue();
		}
		return false;
	}

	@Override
	public IValueReference visitCommaExpression(CommaExpression node) {
		return visit(node.getItems());
	}

	@Override
	public IValueReference visitConditionalOperator(ConditionalOperator node) {
		visit(node.getCondition());
		return merge(visit(node.getTrueValue()), visit(node.getFalseValue()));
	}

	protected static final IAssignProtection PROTECT_CONST = new IAssignProtection() {
		public IProblemIdentifier problemId() {
			return JavaScriptProblems.REASSIGNMENT_OF_CONSTANT;
		}

		public String problemMessage() {
			return ValidationMessages.ReassignmentOfConstant;
		}
	};

	@Override
	public IValueReference visitConstDeclaration(ConstStatement node) {
		final IValueCollection context = peekContext();
		for (VariableDeclaration declaration : node.getVariables()) {
			IValueReference constant = createVariable(context, declaration);
			if (constant != null)
				constant.setAttribute(IAssignProtection.ATTRIBUTE,
						PROTECT_CONST);
		}
		return null;
	}

	protected IValueReference createVariable(IValueCollection context,
			VariableDeclaration declaration) {
		final Identifier identifier = declaration.getIdentifier();
		final String varName = identifier.getName();
		final IValueReference reference = context.createChild(varName);
		final JSVariable variable = new JSVariable();
		variable.setName(declaration.getVariableName());
		if (declaration.getParent() instanceof VariableStatement) {
			for (IModelBuilder extension : this.context.getModelBuilders()) {
				extension.processVariable(declaration, variable, reporter,
						getTypeChecker());
			}
		}
		reference.setAttribute(IReferenceAttributes.VARIABLE, variable);

		reference.setKind(inFunction() ? ReferenceKind.LOCAL
				: ReferenceKind.GLOBAL);
		reference.setLocation(ReferenceLocation.create(getSource(),
				declaration.sourceStart(), declaration.sourceEnd(),
				identifier.sourceStart(), identifier.sourceEnd()));
		initializeVariable(reference, declaration, variable);

		// declared type setting must be done after the initialize else the
		// IMemberEvaluator.valueOf() call will be reverted for types that do
		// return a collection
		final IRVariable rvar = RModelBuilder.create(getContext(), variable);
		reference.setAttribute(IReferenceAttributes.R_VARIABLE, rvar);
		if (rvar.getType() != null) {
			setIRType(reference, rvar.getType(), true);
		}

		return reference;
	}

	protected void initializeVariable(final IValueReference reference,
			VariableDeclaration declaration, IVariable variable) {
		if (declaration.getInitializer() != null) {
			final IValueReference assignment;
			reference
					.setAttribute(IReferenceAttributes.RESOLVING, Boolean.TRUE);
			try {
				assignment = visit(declaration.getInitializer());
			} finally {
				reference.setAttribute(IReferenceAttributes.RESOLVING, null);
			}
			if (assignment != null) {
				assign(reference, assignment);
				if (assignment.getKind() == ReferenceKind.FUNCTION
						&& reference.getAttribute(IReferenceAttributes.METHOD) != null)
					reference.setKind(ReferenceKind.FUNCTION);
			}
		}
	}

	@Override
	public IValueReference visitContinueStatement(ContinueStatement node) {
		return null;
	}

	@Override
	public IValueReference visitDecimalLiteral(DecimalLiteral node) {
		return context.getFactory().createNumber(peekContext());
	}

	@Override
	public IValueReference visitDefaultXmlNamespace(
			DefaultXmlNamespaceStatement node) {
		visit(node.getValue());
		return null;
	}

	@Override
	public IValueReference visitDoWhileStatement(DoWhileStatement node) {
		visit(node.getCondition());
		visit(node.getBody());
		return null;
	}

	@Override
	public IValueReference visitEmptyExpression(EmptyExpression node) {
		return null;
	}

	@Override
	public IValueReference visitEmptyStatement(EmptyStatement node) {
		return null;
	}

	@Override
	public IValueReference visitForEachInStatement(ForEachInStatement node) {
		IValueReference itemReference = visit(node.getItem());
		IValueReference iteratorReference = visit(node.getIterator());
		JSTypeSet typeSet = JavaScriptValidations.getTypes(iteratorReference);
		if (!typeSet.isEmpty()) {
			IRType type = null;
			// try to get the best type, just take the first one, and if the the
			// latter just have Any or None types skip those.
			for (IRType irType : typeSet) {
				if (type == null) {
					type = irType;
				} else if (irType instanceof IRArrayType) {
					IRType itemType = ((IRArrayType) irType).getItemType();
					if (!(itemType instanceof IRNoneType || itemType instanceof IRAnyType)) {
						type = irType;
					}
				} else if (irType instanceof IRMapType) {
					IRType itemType = ((IRMapType) irType).getValueType();
					if (!(itemType instanceof IRNoneType || itemType instanceof IRAnyType)) {
						type = irType;
					}
				}
			}

			if (type instanceof IRArrayType
					&& JavaScriptValidations.typeOf(itemReference) == null) {
				final IRType itemType = ((IRArrayType) type).getItemType();
				setIRType(itemReference, itemType, true);
			} else if (type instanceof IRMapType
					&& JavaScriptValidations.typeOf(itemReference) == null) {
				final IRType itemType = ((IRMapType) type).getValueType();
				setIRType(itemReference, itemType, true);
			} else if (ITypeNames.XMLLIST.equals(type.getName())) {
				itemReference.setDeclaredType(JSTypeSet.ref(context
						.getType(ITypeNames.XML)));
			}
		}
		visit(node.getBody());
		return null;
	}

	@Override
	public IValueReference visitForInStatement(ForInStatement node) {
		final IValueReference item = visit(node.getItem());
		if (item != null) {
			assign(item, context.getFactory().createString(peekContext()));
		}
		visit(node.getIterator());
		visit(node.getBody());
		return null;
	}

	@Override
	public IValueReference visitForStatement(ForStatement node) {
		if (node.getInitial() != null)
			visit(node.getInitial());
		if (node.getCondition() != null)
			visit(node.getCondition());
		if (node.getStep() != null)
			visit(node.getStep());
		if (node.getBody() != null)
			visit(node.getBody());
		return null;
	}

	@Override
	public IValueReference visitFunctionStatement(FunctionStatement node) {
		final JSMethod method = generateJSMethod(node);
		final IValueCollection function = new FunctionValueCollection(
				peekContext(), method.getName(), node.isInlineBlock());

		for (IParameter parameter : method.getParameters()) {
			final IValueReference refArg = function.createChild(parameter
					.getName());
			refArg.setKind(ReferenceKind.ARGUMENT);
			setTypeImpl(refArg, parameter.getType());
			refArg.setLocation(parameter.getLocation());
		}
		final Identifier methodName = node.getName();
		final IValueReference result;
		if (isChildFunction(node)) {
			result = peekContext().createChild(method.getName());
		} else {
			result = new AnonymousValue();
		}
		result.setLocation(method.getLocation());
		result.setKind(ReferenceKind.FUNCTION);
		result.setDeclaredType(JSTypeSet.ref(context
				.getType(ITypeNames.FUNCTION)));
		result.setAttribute(IReferenceAttributes.METHOD, method);
		result.setAttribute(IReferenceAttributes.R_METHOD,
				RModelBuilder.create(getContext(), method));
		result.setAttribute(IReferenceAttributes.FUNCTION_SCOPE, function);
		result.setAttribute(IReferenceAttributes.RESOLVING, Boolean.TRUE);
		enterContext(function);
		Set<IProblemIdentifier> suppressed = null;
		try {
			if (reporter != null && !method.getSuppressedWarnings().isEmpty()) {
				suppressed = new HashSet<IProblemIdentifier>();
				for (IProblemCategory category : method.getSuppressedWarnings()) {
					suppressed.addAll(category.contents());
				}
				reporter.pushSuppressWarnings(suppressed);
			}
			visitFunctionBody(node);
		} finally {
			if (reporter != null && suppressed != null) {
				reporter.popSuppressWarnings();
			}
			leaveContext();
			result.setAttribute(IReferenceAttributes.RESOLVING, null);
		}
		final IValueReference returnValue = result
				.getChild(IValueReference.FUNCTION_OP);
		returnValue.addValue(function.getReturnValue(), true);
		setTypeImpl(returnValue, method.getType());
		return result;
	}

	/**
	 * @param node
	 * @param methodName
	 * @return
	 */
	protected static boolean isChildFunction(FunctionStatement node) {
		return node.getName() != null
				&& !(node.getParent() instanceof BinaryOperation)
				&& !(node.getParent() instanceof VariableDeclaration)
				&& !(node.getParent() instanceof PropertyInitializer)
				&& !(node.getParent() instanceof NewExpression);
	}

	/**
	 * @param node
	 * @return
	 */
	protected JSMethod generateJSMethod(FunctionStatement node) {
		final JSMethod method = new JSMethod(node, getSource());
		for (IModelBuilder extension : context.getModelBuilders()) {
			extension.processMethod(node, method, reporter, getTypeChecker());
		}
		return method;
	}

	public void visitFunctionBody(FunctionStatement node) {
		handleDeclarations(node);
		visit(node.getBody());
	}

	public void setType(IValueReference value, JSType type, boolean lazyEnabled) {
		setTypeImpl(value, type, lazyEnabled);
	}

	private void setTypeImpl(IValueReference value, JSType type) {
		setTypeImpl(value, type, true);
	}

	private void setTypeImpl(IValueReference value, JSType type,
			boolean lazyEnabled) {
		if (type == null) {
			return;
		}
		final IRType rt = JSTypeSet.normalize(getContext(), type);
		setIRType(value, rt, lazyEnabled);
	}

	/**
	 * @param value
	 * @param type
	 * @param lazyEnabled
	 * @param rt
	 */
	private void setIRType(IValueReference value, final IRType rt,
			boolean lazyEnabled) {
		if (rt instanceof IRSimpleType) {
			final Type t = ((IRSimpleType) rt).getTarget();
			if (t.getKind() != TypeKind.UNKNOWN) {
				value.setDeclaredType(rt);
				if (value instanceof IValueProvider) {
					for (IMemberEvaluator evaluator : TypeInfoManager
							.getMemberEvaluators()) {
						final IValueCollection collection = evaluator.valueOf(
								context, t);
						if (collection != null) {
							if (collection instanceof IValueProvider) {
								((IValueProvider) value).getValue().addValue(
										((IValueProvider) collection)
												.getValue());
							}
						}
					}
				}
			} else if (lazyEnabled) {
				value.addValue(new LazyTypeReference(context, t.getName(),
						peekContext()), false);
			}
		} else {
			value.setDeclaredType(rt);
		}
	}

	@Override
	public IValueReference visitGetAllChildrenExpression(
			GetAllChildrenExpression node) {
		return context.getFactory().createXMLList(peekContext());
	}

	@Override
	public IValueReference visitGetArrayItemExpression(
			GetArrayItemExpression node) {
		final IValueReference array = visit(node.getArray());
		visit(node.getIndex());
		if (array != null) {
			// always just create the ARRAY_OP child (for code completion)
			IValueReference child = array.getChild(IValueReference.ARRAY_OP);
			IRType arrayType = null;
			if (array.getDeclaredType() != null) {
				arrayType = TypeUtil.extractArrayItemType(array
						.getDeclaredType());
			} else {
				JSTypeSet types = array.getTypes();
				if (types.size() > 0)
					arrayType = TypeUtil.extractArrayItemType(types.getFirst());
			}
			if (arrayType != null && child.getDeclaredType() == null) {
				setIRType(child, arrayType, true);
			}
			if (node.getIndex() instanceof StringLiteral) {
				IValueReference namedChild = extractNamedChild(array,
						node.getIndex());
				if (namedChild.exists()) {
					child = namedChild;
					if (arrayType != null && child.getDeclaredType() == null) {
						child.setDeclaredType(arrayType);
					}
				}
			}
			return child;
		}
		return null;
	}

	@Override
	public IValueReference visitGetLocalNameExpression(
			GetLocalNameExpression node) {
		return null;
	}

	@Override
	public IValueReference visitIdentifier(Identifier node) {
		return peekContext().getChild(node.getName());

	}

	private Boolean evaluateCondition(Expression condition) {
		if (condition instanceof BooleanLiteral) {
			return Boolean.valueOf(((BooleanLiteral) condition).getText());
		} else {
			return null;
		}
	}

	@Override
	public IValueReference visitIfStatement(IfStatement node) {
		visit(node.getCondition());
		visitIfStatements(node);
		return null;
	}

	protected void visitIfStatements(IfStatement node) {
		final List<Statement> statements = new ArrayList<Statement>(2);
		Statement onlyBranch = null;
		final Boolean condition = evaluateCondition(node.getCondition());
		if ((condition == null || condition.booleanValue())
				&& node.getThenStatement() != null) {
			statements.add(node.getThenStatement());
			if (condition != null && condition.booleanValue()) {
				onlyBranch = node.getThenStatement();
			}
		}
		if ((condition == null || !condition.booleanValue())
				&& node.getElseStatement() != null) {
			statements.add(node.getElseStatement());
			if (condition != null && !condition.booleanValue()) {
				onlyBranch = node.getElseStatement();
			}
		}
		if (!statements.isEmpty()) {
			if (statements.size() == 1) {
				if (statements.get(0) == onlyBranch) {
					visit(statements.get(0));
				} else {
					final Branching branching = branching();
					visit(statements.get(0));
					branching.end();
				}
			} else {
				final Branching branching = branching();
				final List<NestedValueCollection> collections = new ArrayList<NestedValueCollection>(
						statements.size());
				for (Statement statement : statements) {
					final NestedValueCollection nestedCollection = new NestedValueCollection(
							peekContext());
					enterContext(nestedCollection);
					visit(statement);
					leaveContext();
					collections.add(nestedCollection);
				}
				NestedValueCollection.mergeTo(peekContext(), collections);
				branching.end();
			}
		}
	}

	@Override
	public IValueReference visitLabelledStatement(LabelledStatement node) {
		if (node.getStatement() != null)
			visit(node.getStatement());
		return null;
	}

	protected static class AnonymousNewValue extends AnonymousValue {
		@Override
		public IValueReference getChild(String name) {
			if (name.equals(IValueReference.FUNCTION_OP))
				return this;
			return super.getChild(name);
		}
	}

	public static class VisitNewResult {
		IValueReference typeValue;
		IValueReference[] arguments;
		IValueReference value;

		public IValueReference getValue() {
			return value;
		}

		public IValueReference getTypeValue() {
			return typeValue;
		}

		public IValueReference[] getArguments() {
			return arguments;
		}
	}

	protected VisitNewResult visitNew(NewExpression node) {
		final VisitNewResult result = new VisitNewResult();
		Expression objectClass = node.getObjectClass();
		if (objectClass instanceof CallExpression) {
			final CallExpression call = (CallExpression) objectClass;
			result.arguments = new IValueReference[call.getArguments().size()];
			int index = 0;
			for (ASTNode argument : call.getArguments()) {
				result.arguments[index++] = visit(argument);
			}
			objectClass = call.getExpression();
		} else {
			result.arguments = new IValueReference[0];
		}
		result.typeValue = visit(objectClass);

		if (result.typeValue != null) {
			if (result.typeValue.getKind() == ReferenceKind.FUNCTION) {
				Object fs = result.typeValue
						.getAttribute(IReferenceAttributes.FUNCTION_SCOPE);
				if (fs instanceof IValueCollection
						&& ((IValueCollection) fs).getThis() != null) {
					result.value = new AnonymousNewValue();
					result.value.setValue(((IValueCollection) fs).getThis());
					result.value.setKind(ReferenceKind.TYPE);
					String className = PropertyExpressionUtils
							.getPath(objectClass);
					if (className != null) {
						Type type = TypeInfoModelFactory.eINSTANCE.createType();
						type.setSuperType(context.getKnownType(OBJECT, null));
						type.setKind(TypeKind.JAVASCRIPT);
						type.setName(className);
						result.value.setDeclaredType(JSTypeSet.ref(type));
					} else {
						result.value.setDeclaredType(JSTypeSet.ref(OBJECT));
					}
				}
			} else if (result.typeValue.exists()) {
				for (IRType type : result.typeValue.getDeclaredTypes()) {
					if (type instanceof IRClassType) {
						result.value = new AnonymousNewValue();
						result.value.setKind(ReferenceKind.TYPE);
						result.value.setDeclaredType(((IRClassType) type)
								.toItemType());
						return result;
					}
				}
				for (IRType type : result.typeValue.getTypes()) {
					if (type instanceof IRClassType) {
						result.value = new AnonymousNewValue();
						result.value.setKind(ReferenceKind.TYPE);
						result.value.setDeclaredType(((IRClassType) type)
								.toItemType());
						return result;
					}
				}
			}
		}
		if (result.value == null) {
			final String className = PropertyExpressionUtils
					.getPath(objectClass);
			IValueCollection contextValueCollection = peekContext();
			if (className != null) {
				Type knownType = context.getKnownType(className, TypeMode.CODE);
				if (knownType != null) {
					result.value = new AnonymousNewValue();
					result.value.setValue(context.getFactory().create(
							contextValueCollection, JSTypeSet.ref(knownType)));
					result.value.setKind(ReferenceKind.TYPE);
				} else {
					result.value = new LazyTypeReference(context, className,
							contextValueCollection);
				}
			} else {
				result.value = new AnonymousNewValue();
				result.value.setValue(context.getFactory().createObject(
						contextValueCollection));
			}
		}
		return result;
	}

	@Override
	public IValueReference visitNewExpression(NewExpression node) {
		return visitNew(node).getValue();
	}

	@Override
	public IValueReference visitNullExpression(NullExpression node) {
		return null;
	}

	@Override
	public IValueReference visitObjectInitializer(ObjectInitializer node) {
		final IValueReference result = new AnonymousValue();
		result.setDeclaredType(JSTypeSet.ref(OBJECT));
		for (ObjectInitializerPart part : node.getInitializers()) {
			if (part instanceof PropertyInitializer) {
				final PropertyInitializer pi = (PropertyInitializer) part;
				final IValueReference child = extractNamedChild(result,
						pi.getName());
				final IValueReference value = visit(pi.getValue());
				if (child != null) {
					child.setValue(value);
					child.setLocation(ReferenceLocation.create(getSource(), pi
							.getName().sourceStart(), pi.getName().sourceEnd()));
					if (child.getKind() == ReferenceKind.UNKNOWN) {
						child.setKind(ReferenceKind.FIELD);
					}
				}
			} else {
				// TODO handle get/set methods
			}
		}
		return result;
	}

	@Override
	public IValueReference visitParenthesizedExpression(
			ParenthesizedExpression node) {
		return visit(node.getExpression());
	}

	@Override
	public IValueReference visitPropertyExpression(PropertyExpression node) {
		final IValueReference object = visit(node.getObject());
		return extractNamedChild(object, node.getProperty());
	}

	protected IValueReference extractNamedChild(IValueReference parent,
			Expression name) {
		if (parent != null) {
			final String nameStr;
			if (name instanceof Identifier) {
				nameStr = ((Identifier) name).getName();
				IRType parentType = JavaScriptValidations.typeOf(parent);
				if (parentType != null && isXML(parentType)) {
					IValueReference child = parent.getChild(nameStr);
					if (child != null && child.getDeclaredType() == null) {
						child.setDeclaredType(JSTypeSet.ref(ITypeNames.XML));
						return child;
					}
				}
			} else if (name instanceof StringLiteral) {
				nameStr = ((StringLiteral) name).getValue();
			} else if (name instanceof XmlAttributeIdentifier) {
				if (((XmlAttributeIdentifier) name).getExpression() instanceof AsteriskExpression) {
					return visitAsteriskExpression((AsteriskExpression) ((XmlAttributeIdentifier) name)
							.getExpression());
				} else {
					nameStr = ((XmlAttributeIdentifier) name)
							.getAttributeName();
					IValueReference child = parent.getChild(nameStr);
					if (child != null && child.getDeclaredType() == null) {
						child.setDeclaredType(JSTypeSet.ref(ITypeNames.XML));
						return child;
					}
				}
			} else if (name instanceof AsteriskExpression) {
				return visitAsteriskExpression((AsteriskExpression) name);
			} else if (name instanceof ParenthesizedExpression) {
				visitParenthesizedExpression((ParenthesizedExpression) name);
				return parent;
			} else {
				return null;
			}
			return parent.getChild(nameStr);
		}
		return null;
	}

	@Override
	public IValueReference visitRegExpLiteral(RegExpLiteral node) {
		return context.getFactory().createRegExp(peekContext());
	}

	@Override
	public IValueReference visitReturnStatement(ReturnStatement node) {
		if (node.getValue() != null) {
			final IValueReference value = visit(node.getValue());
			if (value != null) {
				final IValueReference returnValue = peekContext()
						.getReturnValue();
				if (returnValue != null) {
					returnValue.addValue(value,
							!(value instanceof LazyTypeReference));
				}
			}
			return value;
		}
		return null;
	}

	@Override
	public IValueReference visitScript(Script node) {
		handleDeclarations(node);
		return visit(node.getStatements());
	}

	private void handleDeclarations(JSScope scope) {
		for (JSDeclaration declaration : scope.getDeclarations()) {
			if (declaration instanceof FunctionStatement) {

			} else if (declaration instanceof VariableDeclaration) {

			}
		}
	}

	@Override
	public IValueReference visitStatementBlock(StatementBlock node) {
		for (Statement statement : node.getStatements()) {
			visit(statement);
		}
		return null;
	}

	@Override
	public IValueReference visitStringLiteral(StringLiteral node) {
		return context.getFactory().createString(peekContext());
	}

	@Override
	public IValueReference visitSwitchStatement(SwitchStatement node) {
		if (node.getCondition() != null)
			visit(node.getCondition());
		for (SwitchComponent component : node.getCaseClauses()) {
			if (component instanceof CaseClause) {
				visit(((CaseClause) component).getCondition());
			}
			visit(component.getStatements());
		}
		return null;
	}

	@Override
	public IValueReference visitThisExpression(ThisExpression node) {
		return peekContext().getThis();
	}

	@Override
	public IValueReference visitThrowStatement(ThrowStatement node) {
		if (node.getException() != null)
			visit(node.getException());
		return null;
	}

	@Override
	public IValueReference visitTryStatement(TryStatement node) {
		visit(node.getBody());
		for (CatchClause catchClause : node.getCatches()) {
			final NestedValueCollection collection = new NestedValueCollection(
					peekContext());
			IValueReference exception = collection.createChild(catchClause
					.getException().getName());
			exception.setDeclaredType(JSTypeSet.ref(ITypeNames.ERROR));

			enterContext(collection);
			if (catchClause.getStatement() != null) {
				visit(catchClause.getStatement());
			}
			leaveContext();
		}
		if (node.getFinally() != null) {
			visit(node.getFinally().getStatement());
		}
		return null;
	}

	@Override
	public IValueReference visitUnaryOperation(UnaryOperation node) {
		if (node.getOperation() == JSParser.NOT) {
			visit(node.getExpression());
			return context.getFactory().createBoolean(peekContext());
		} else if (node.getOperation() == JSParser.DELETE) {
			final IValueReference value = visit(node.getExpression());
			if (value != null) {
				value.delete();
			}
			return context.getFactory().createBoolean(peekContext());
		} else if (node.getOperation() == JSParser.TYPEOF) {
			visit(node.getExpression());
			return context.getFactory().createString(peekContext());
		} else if (node.getOperation() == JSParser.VOID) {
			visit(node.getExpression());
			return null;
		} else {
			return visit(node.getExpression());
		}
	}

	@Override
	public IValueReference visitVariableStatement(VariableStatement node) {
		final IValueCollection collection = peekContext();
		IValueReference result = null;
		for (VariableDeclaration declaration : node.getVariables()) {
			result = createVariable(collection, declaration);
		}
		return result;
	}

	@Override
	public IValueReference visitVoidExpression(VoidExpression node) {
		visit(node.getExpression());
		return null;
	}

	@Override
	public IValueReference visitWhileStatement(WhileStatement node) {
		if (node.getCondition() != null)
			visit(node.getCondition());
		if (node.getBody() != null)
			visit(node.getBody());
		return null;
	}

	@Override
	public IValueReference visitWithStatement(WithStatement node) {
		final IValueReference with = visit(node.getExpression());
		if (with != null) {
			final WithValueCollection withCollection = new WithValueCollection(
					peekContext(), with);
			enterContext(withCollection);
			visit(node.getStatement());
			leaveContext();
		} else {
			visit(node.getStatement());
		}
		return null;
	}

	private static final DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory
			.newInstance();
	private DocumentBuilder docBuilder;

	/**
	 * @return
	 * @throws ParserConfigurationException
	 */
	private DocumentBuilder getDocumentBuilder()
			throws ParserConfigurationException {
		if (docBuilder == null)
			docBuilder = docBuilderFactory.newDocumentBuilder();
		return docBuilder;
	}

	@Override
	public IValueReference visitXmlLiteral(XmlLiteral node) {
		IValueReference xmlValueReference = context.getFactory().createXML(
				peekContext());

		if (xmlValueReference instanceof IValueProvider) {
			IRType xmlType = JSTypeSet.ref(context.getKnownType(ITypeNames.XML,
					null));
			IValue xmlValue = ((IValueProvider) xmlValueReference).getValue();
			List<XmlFragment> fragments = node.getFragments();
			StringBuilder xml = new StringBuilder();
			for (XmlFragment xmlFragment : fragments) {
				if (xmlFragment instanceof XmlTextFragment) {
					String xmlText = ((XmlTextFragment) xmlFragment).getXml();
					if (xmlText.equals("<></>"))
						continue;
					if (xmlText.startsWith("<>") && xmlText.endsWith("</>")) {
						xmlText = "<xml>"
								+ xmlText.substring(2, xmlText.length() - 3)
								+ "</xml>";
					}
					xml.append(xmlText);
				} else if (xmlFragment instanceof XmlExpressionFragment) {
					Expression expression = ((XmlExpressionFragment) xmlFragment)
							.getExpression();
					visit(expression);
					if (xml.charAt(xml.length() - 1) == '<'
							|| xml.subSequence(xml.length() - 2, xml.length())
									.equals("</")) {
						if (expression instanceof Identifier) {
							xml.append(((Identifier) expression).getName());
						} else {
							xml.setLength(0);
							break;
						}
					} else
						xml.append("\"\" ");
				}
			}

			if (xml.length() > 0) {
				try {
					DocumentBuilder docBuilder = getDocumentBuilder();
					Document doc = docBuilder.parse(new InputSource(
							new StringReader(xml.toString())));
					NodeList nl = doc.getChildNodes();
					if (nl.getLength() == 1) {
						Node item = nl.item(0);
						NamedNodeMap attributes = item.getAttributes();
						for (int a = 0; a < attributes.getLength(); a++) {
							Node attribute = attributes.item(a);
							xmlValue.createChild("@" + attribute.getNodeName(),
									0);
						}
						createXmlChilds(xmlType, xmlValue, item.getChildNodes());
					} else {
						System.err.println("root should be 1 child?? " + xml);
					}
				} catch (Exception e) {
				}
			}
		}
		return xmlValueReference;
	}

	/**
	 * @param xmlType
	 * @param xmlValue
	 * @param nl
	 */
	private void createXmlChilds(IRType xmlType, IValue xmlValue, NodeList nl) {
		for (int i = 0; i < nl.getLength(); i++) {
			Node item = nl.item(i);
			if (item.getNodeType() == Node.TEXT_NODE) {
				String value = item.getNodeValue();
				if (value == null || "".equals(value.trim())) {
					continue;
				}
			}
			IValue nodeValue = xmlValue.createChild(item.getNodeName(), 0);
			nodeValue.setDeclaredType(xmlType);
			NamedNodeMap attributes = item.getAttributes();
			if (attributes != null) {
				for (int a = 0; a < attributes.getLength(); a++) {
					Node attribute = attributes.item(a);
					nodeValue.createChild("@" + attribute.getNodeName(), 0);
				}
			}
			createXmlChilds(xmlType, nodeValue, item.getChildNodes());
		}
	}

	@Override
	public IValueReference visitXmlPropertyIdentifier(
			XmlAttributeIdentifier node) {
		return context.getFactory().createXML(peekContext());
	}

	@Override
	public IValueReference visitYieldOperator(YieldOperator node) {
		final IValueReference value = visit(node.getExpression());
		if (value != null) {
			final IValueReference reference = peekContext().getReturnValue();
			if (reference != null) {
				reference.addValue(value, true);
			}
		}
		return null;
	}

	public static boolean isFunctionDeclaration(Expression expression) {
		PropertyExpression pe = null;
		if (expression instanceof PropertyExpression)
			pe = (PropertyExpression) expression;
		else if (expression.getParent() instanceof PropertyExpression)
			pe = (PropertyExpression) expression.getParent();
		if (pe != null && pe.getObject() instanceof ThisExpression
				&& pe.getParent() instanceof BinaryOperation) {
			return ((BinaryOperation) pe.getParent()).getRightExpression() instanceof FunctionStatement;
		}
		return false;
	}

}