org.eclipse.xtext.xbase.XReturnExpression Java Examples

@Check
public void checkInvalidReturnExpression(XExpression expression) {
	final EReference contFeature = (EReference) expression.eContainingFeature();
	final Map<EReference, EarlyExitKind> map = getDisallowedEarlyExitReferences();
	if (map.containsKey(contFeature)) {
		EarlyExitKind exitKind = map.get(contFeature);
		List<XExpression> returns = newArrayList();
		collectExits(expression, returns);
		for (XExpression expr : returns) {
			if (expr instanceof XReturnExpression && (exitKind == EarlyExitKind.RETURN || exitKind == EarlyExitKind.BOTH)) {
				error("A return expression is not allowed in this context.", expr, null, IssueCodes.INVALID_EARLY_EXIT);
			}
			if (expr instanceof XThrowExpression && (exitKind == EarlyExitKind.THROW || exitKind == EarlyExitKind.BOTH)) {
				error("A throw expression is not allowed in this context.", expr, null, IssueCodes.INVALID_EARLY_EXIT);
			}
		}
	}
}
 

protected void checkValidReturn(XReturnExpression object, ITypeComputationState state) {
	// if the expectation comes from a method's return type
	// then it is legal, thus we must check if the return is
	// contained in a throw expression
	if (hasThrowableExpectation(state) &&
			EcoreUtil2.getContainerOfType(object, XThrowExpression.class) != null) {
		state.addDiagnostic(new EObjectDiagnosticImpl(
				Severity.ERROR,
				IssueCodes.INVALID_RETURN,
				"Invalid return inside throw.",
				object,
				null,
				-1,
				new String[] { 
				}));
	}
}
 

protected void checkValidReturnExpression(XExpression returnValue, ITypeComputationState expressionState) {
	ITypeComputationResult result = expressionState.computeTypes(returnValue);
	LightweightTypeReference actualType = result.getActualExpressionType();
	int conformanceFlags = result.getConformanceFlags();
	if (actualType.isPrimitiveVoid() && (conformanceFlags & ConformanceFlags.NO_IMPLICIT_RETURN) != 0) {
		String message = "Invalid return's expression.";
		if (returnValue instanceof XReturnExpression) {
			// when the return's expression is directory a return
			// we provide a more detailed error
			message = "Return cannot be nested.";
		}
		expressionState.addDiagnostic(new EObjectDiagnosticImpl(
				Severity.ERROR,
				IssueCodes.INVALID_RETURN,
				message,
				returnValue,
				null,
				-1,
				new String[] { 
				}));
	}
}
 

@Test public void testReturnTypeInConstructor_02() throws Exception {
	XtendConstructor constructor = constructor(
			"new() {\n" + 
			"	return ''.toString\n" + 
			"}\n", false);
	XBlockExpression body = (XBlockExpression) constructor.getExpression();
	assertEquals("void", getExpectedType(body).getIdentifier());
	assertEquals("void", getExpectedReturnType(body).getIdentifier());
	XReturnExpression returnExpression = (XReturnExpression) body.getExpressions().get(0);
	XMemberFeatureCall toString = (XMemberFeatureCall) returnExpression.getExpression();
	assertEquals("void", getExpectedType(toString).getIdentifier());
	assertEquals("void", getExpectedReturnType(toString).getIdentifier());
}
 

protected void _format(final XReturnExpression expr, final FormattableDocument format) {
  final Procedure1<FormattingDataInit> _function = (FormattingDataInit it) -> {
    it.oneSpace();
  };
  Function1<? super FormattableDocument, ? extends Iterable<FormattingData>> _prepend = this._formattingDataFactory.prepend(this._nodeModelAccess.nodeForEObject(expr.getExpression()), _function);
  format.operator_add(_prepend);
  this.format(expr.getExpression(), format);
}
 

protected Collection<IEarlyExitComputer.ExitPoint> exitPoints(final XExpression expression) {
  if (expression instanceof XDoWhileExpression) {
    return _exitPoints((XDoWhileExpression)expression);
  } else if (expression instanceof XWhileExpression) {
    return _exitPoints((XWhileExpression)expression);
  } else if (expression instanceof XAbstractFeatureCall) {
    return _exitPoints((XAbstractFeatureCall)expression);
  } else if (expression instanceof XBasicForLoopExpression) {
    return _exitPoints((XBasicForLoopExpression)expression);
  } else if (expression instanceof XBlockExpression) {
    return _exitPoints((XBlockExpression)expression);
  } else if (expression instanceof XConstructorCall) {
    return _exitPoints((XConstructorCall)expression);
  } else if (expression instanceof XForLoopExpression) {
    return _exitPoints((XForLoopExpression)expression);
  } else if (expression instanceof XIfExpression) {
    return _exitPoints((XIfExpression)expression);
  } else if (expression instanceof XReturnExpression) {
    return _exitPoints((XReturnExpression)expression);
  } else if (expression instanceof XSwitchExpression) {
    return _exitPoints((XSwitchExpression)expression);
  } else if (expression instanceof XSynchronizedExpression) {
    return _exitPoints((XSynchronizedExpression)expression);
  } else if (expression instanceof XThrowExpression) {
    return _exitPoints((XThrowExpression)expression);
  } else if (expression instanceof XTryCatchFinallyExpression) {
    return _exitPoints((XTryCatchFinallyExpression)expression);
  } else if (expression instanceof XVariableDeclaration) {
    return _exitPoints((XVariableDeclaration)expression);
  } else if (expression != null) {
    return _exitPoints(expression);
  } else {
    throw new IllegalArgumentException("Unhandled parameter types: " +
      Arrays.<Object>asList(expression).toString());
  }
}
 

public boolean hasReturnExpression(final XExpression expression) {
  boolean _switchResult = false;
  boolean _matched = false;
  if (expression instanceof XReturnExpression) {
    _matched=true;
    _switchResult = true;
  }
  if (!_matched) {
    if (expression instanceof XThrowExpression) {
      _matched=true;
      _switchResult = true;
    }
  }
  if (!_matched) {
    if (expression instanceof XClosure) {
      _matched=true;
      _switchResult = false;
    }
  }
  if (!_matched) {
    final Function1<EObject, Boolean> _function = (EObject content) -> {
      boolean _switchResult_1 = false;
      boolean _matched_1 = false;
      if (content instanceof XExpression) {
        _matched_1=true;
        _switchResult_1 = this.hasReturnExpression(((XExpression)content));
      }
      if (!_matched_1) {
        _switchResult_1 = false;
      }
      return Boolean.valueOf(_switchResult_1);
    };
    _switchResult = IterableExtensions.<EObject>exists(expression.eContents(), _function);
  }
  return _switchResult;
}
 

protected void _format(final XReturnExpression expr, @Extension final IFormattableDocument format) {
  final Procedure1<IHiddenRegionFormatter> _function = (IHiddenRegionFormatter it) -> {
    it.oneSpace();
  };
  format.<XExpression>prepend(expr.getExpression(), _function);
  format.<XExpression>format(expr.getExpression());
}
 

@Test public void testReturnExpressionInBlock_1() throws Exception {
	XBlockExpression block = (XBlockExpression) expression(
		"{ return 1 2 }");
	assertEquals(2, block.getExpressions().size());
	assertTrue(block.getExpressions().get(0) instanceof XReturnExpression);
	XReturnExpression returnExpression = (XReturnExpression) block.getExpressions().get(0);
	assertTrue(returnExpression.getExpression() instanceof XNumberLiteral);
}
 

@Test public void testReturnExpressionInBlock_2() throws Exception {
	XBlockExpression block = (XBlockExpression) expression(
		"{ return }");
	assertEquals(1, block.getExpressions().size());
	assertTrue(block.getExpressions().get(0) instanceof XReturnExpression);
	XReturnExpression returnExpression = (XReturnExpression) block.getExpressions().get(0);
	assertNull(returnExpression.getExpression());
}
 

@Test public void testReturnExpressionInBlock_3() throws Exception {
	XBlockExpression block = (XBlockExpression) expression(
		"{ return; 1 2 }");
	assertEquals(3, block.getExpressions().size());
	assertTrue(block.getExpressions().get(0) instanceof XReturnExpression);
	XReturnExpression returnExpression = (XReturnExpression) block.getExpressions().get(0);
	assertNull(returnExpression.getExpression());
}
 

@Test
public void testFeatureCallVarArgument_04() {
  ExpectationTestingTypeComputer _typeComputer = this.getTypeComputer();
  final Function1<XExpression, Boolean> _function = (XExpression it) -> {
    return Boolean.valueOf((it instanceof XReturnExpression));
  };
  _typeComputer.setPredicate(_function);
  this.expects("new foo.ClassWithGenericMethod().genericMethod(return null)").types("Unbound[T]").finalizedAs("Object");
}
 

/**
 * @param isReferenced unused in this context but necessary for dispatch signature 
 */
protected void _toJavaStatement(XReturnExpression expr, ITreeAppendable b, boolean isReferenced) {
	if (expr.getExpression()!=null) {
		internalToJavaStatement(expr.getExpression(), b, true);
		b.newLine().append("return ");
		LightweightTypeReference returnTypeToCompile = findRealReturnType(expr);
		internalToConvertedExpression(expr.getExpression(), b, returnTypeToCompile);
		b.append(";");
	} else {
		b.newLine().append("return;");
	}
}
 

@Override
protected void internalToConvertedExpression(XExpression obj, ITreeAppendable appendable) {
	if (obj instanceof XBlockExpression) {
		_toJavaExpression((XBlockExpression) obj, appendable);
	} else if (obj instanceof XCastedExpression) {
		_toJavaExpression((XCastedExpression) obj, appendable);
	} else if (obj instanceof XClosure) {
		_toJavaExpression((XClosure) obj, appendable);
	} else if (obj instanceof XAnnotation) {
		_toJavaExpression((XAnnotation) obj, appendable);
	} else if (obj instanceof XConstructorCall) {
		_toJavaExpression((XConstructorCall) obj, appendable);
	} else if (obj instanceof XIfExpression) {
		_toJavaExpression((XIfExpression) obj, appendable);
	} else if (obj instanceof XInstanceOfExpression) {
		_toJavaExpression((XInstanceOfExpression) obj, appendable);
	} else if (obj instanceof XSwitchExpression) {
		_toJavaExpression((XSwitchExpression) obj, appendable);
	} else if (obj instanceof XTryCatchFinallyExpression) {
		_toJavaExpression((XTryCatchFinallyExpression) obj, appendable);
	} else if (obj instanceof XListLiteral) {
		_toJavaExpression((XListLiteral) obj, appendable);
	} else if (obj instanceof XSetLiteral) {
		_toJavaExpression((XSetLiteral) obj, appendable);
	} else if (obj instanceof XSynchronizedExpression) {
		_toJavaExpression((XSynchronizedExpression) obj, appendable);
	} else if (obj instanceof XReturnExpression) {
		_toJavaExpression((XReturnExpression) obj, appendable);
	} else if (obj instanceof XThrowExpression) {
		_toJavaExpression((XThrowExpression) obj, appendable);
	} else {
		super.internalToConvertedExpression(obj, appendable);
	}
}
 

@Check
public void checkNoReturnsInCreateExtensions(XtendFunction func) {
	if (func.getCreateExtensionInfo() == null)
		return;
	List<XReturnExpression> found = newArrayList();
	collectReturnExpressions(func.getCreateExtensionInfo().getCreateExpression(), found);
	for (XReturnExpression xReturnExpression : found) {
		error("Return is not allowed in creation expression", xReturnExpression, null, INVALID_EARLY_EXIT);
	}
}
 

protected void _computeTypes(XReturnExpression object, ITypeComputationState state) {
	XExpression returnValue = object.getExpression();
	ITypeComputationState expressionState = state.withReturnExpectation();

	checkValidReturn(object, state);
	
	LightweightTypeReference primitiveVoid = getPrimitiveVoid(state);
	if (returnValue != null) {
		checkValidReturnExpression(returnValue, expressionState);
		state.acceptActualType(primitiveVoid, ConformanceFlags.NO_IMPLICIT_RETURN);
	} else {
		state.acceptActualType(primitiveVoid, ConformanceFlags.EXPLICIT_VOID_RETURN);
		state.acceptActualType(primitiveVoid, ConformanceFlags.NO_IMPLICIT_RETURN);
	}
}
 

protected void collectReturnExpressions(EObject expr, List<XReturnExpression> found) {
	if (expr instanceof XReturnExpression) {
		found.add((XReturnExpression) expr);
	} else if (expr instanceof XClosure) {
		return;
	}
	for (EObject child : expr.eContents()) {
		collectReturnExpressions(child, found);
	}
}
 

protected void collectExits(EObject expr, List<XExpression> found) {
	if (expr instanceof XReturnExpression) {
		found.add((XExpression) expr);
	} else if (expr instanceof XThrowExpression) {
		found.add((XExpression) expr);
	} else if (expr instanceof XClosure) {
		return;
	}
	for (EObject child : expr.eContents()) {
		collectExits(child, found);
	}
}
 

/**
 * Checks that return expressions do not occur in check implementations.
 *
 * @param expression
 *          the expression
 */
@Check
public void checkReturnExpressions(final XReturnExpression expression) {
  if (expression.getExpression() != null) {
    error(Messages.CheckJavaValidator_NO_RETURN_IN_CHECK_IMPL, XbasePackage.Literals.XRETURN_EXPRESSION__EXPRESSION, IssueCodes.RETURN_IN_IMPL);
  }
}
 

@Check
public void checkReturn(XReturnExpression expr) {
	XExpression returnedExpression = expr.getExpression();
	IResolvedTypes resolvedTypes = typeResolver.resolveTypes(expr);
	LightweightTypeReference expectedReturnType = resolvedTypes.getExpectedReturnType(expr);
	if (expectedReturnType == null) {
		return;
	}
	if (expectedReturnType.isPrimitiveVoid()) {
		if (returnedExpression != null)
			error("Void functions cannot return a value.", expr, null,
					ValidationMessageAcceptor.INSIGNIFICANT_INDEX, INVALID_RETURN);
	} else {
		if (returnedExpression == null)
			error("The function must return a result of type " + expectedReturnType.getHumanReadableName() + ".", expr, null,
					ValidationMessageAcceptor.INSIGNIFICANT_INDEX, INVALID_RETURN);
		else {
			LightweightTypeReference expressionType = getActualType(returnedExpression);
			if (expressionType.isPrimitiveVoid()) {
				error("Incompatible types. Expected " + getNameOfTypes(expectedReturnType) + " but was "
						+ canonicalName(expressionType), returnedExpression, null,
						ValidationMessageAcceptor.INSIGNIFICANT_INDEX, INCOMPATIBLE_TYPES);
			}
		}

	}
}
 

private static XExpression filterSingleOperation(XExpression expression) {
	XExpression content = expression;
	while (content instanceof XBlockExpression) {
		final XBlockExpression blockExpr = (XBlockExpression) content;
		if (blockExpr.getExpressions().size() == 1) {
			content = blockExpr.getExpressions().get(0);
		} else {
			content = null;
		}
	}
	if (content instanceof XReturnExpression) {
		content = ((XReturnExpression) content).getExpression();
	}
	return content;
}
 

@Override
public RefactoringStatus checkInitialConditions(final IProgressMonitor pm) throws CoreException,
		OperationCanceledException {
	StatusWrapper status = statusProvider.get();
	IResolvedTypes resolvedTypes = typeResolver.resolveTypes(firstExpression, new CancelIndicator() {
		@Override
		public boolean isCanceled() {
			return pm.isCanceled();
		}
	});
	try {
		Set<String> calledExternalFeatureNames = newHashSet();
		returnType = calculateReturnType(resolvedTypes);
		if (returnType != null && !equal("void", returnType.getIdentifier()))
			returnExpression = lastExpression;
		boolean isReturnAllowed = isEndOfOriginalMethod(); 
		for (EObject element : EcoreUtil2.eAllContents(originalMethod.getExpression())) {
			if (pm.isCanceled()) {
				throw new OperationCanceledException();
			}
			boolean isLocalExpression = EcoreUtil.isAncestor(expressions, element);
			if (element instanceof XFeatureCall) {
				XFeatureCall featureCall = (XFeatureCall) element;
				JvmIdentifiableElement feature = featureCall.getFeature();
				LightweightTypeReference featureType = resolvedTypes.getActualType(featureCall);
				boolean isLocalFeature = EcoreUtil.isAncestor(expressions, feature);
				if (!isLocalFeature && isLocalExpression) {
					// call-out
					if (feature instanceof JvmFormalParameter || feature instanceof XVariableDeclaration) {
						if (!calledExternalFeatureNames.contains(feature.getSimpleName())) {
							calledExternalFeatureNames.add(feature.getSimpleName());
							ParameterInfo parameterInfo = new ParameterInfo(featureType.getIdentifier(), 
									feature.getSimpleName(), 
									parameterInfos.size());
							parameterInfos.add(parameterInfo);
							parameter2type.put(parameterInfo, featureType);
						}
						externalFeatureCalls.put(feature.getSimpleName(), featureCall);
					}
				} else if (isLocalFeature && !isLocalExpression) {
					// call-in
					if (returnExpression != null) {
						status.add(RefactoringStatus.FATAL,
								"Ambiguous return value: Multiple local variables are accessed in subsequent code.");
						break;
					}
					returnExpression = featureCall;
					returnType = featureType;
				}
			} else if(isLocalExpression) {
				if(element instanceof XReturnExpression && !isReturnAllowed) {
					status.add(RefactoringStatus.FATAL,
						"Extracting method would break control flow due to return statements.");
					break;
				} else if (element instanceof JvmTypeReference) {
					JvmType type = ((JvmTypeReference) element).getType();
					if (type instanceof JvmTypeParameter) {
						JvmOperation operation = associations.getDirectlyInferredOperation(originalMethod);
						if (operation != null) {
							List<JvmTypeParameter> typeParameters = operation.getTypeParameters();
							if (typeParameters.contains(type)) 
								neededTypeParameters.add((JvmTypeParameter) type);
						}
					}
				} else if (element instanceof JvmFormalParameter)
					localFeatureNames.add(((JvmFormalParameter) element).getName());
				else if (element instanceof XVariableDeclaration)
					localFeatureNames.add(((XVariableDeclaration) element).getIdentifier());
			}
		}
	} catch (OperationCanceledException e) {
		throw e;
	} catch (Exception exc) {
		handleException(exc, status);
	}
	return status.getRefactoringStatus();
}
 

@Deprecated
protected void sequence_XReturnExpression(EObject context, XReturnExpression semanticObject) {
	sequence_XReturnExpression(createContext(context, semanticObject), semanticObject);
}
 

protected Collection<IEarlyExitComputer.ExitPoint> _exitPoints(final XReturnExpression expression) {
  IEarlyExitComputer.ExitPoint _exitPoint = new IEarlyExitComputer.ExitPoint(expression, false);
  return Collections.<IEarlyExitComputer.ExitPoint>singletonList(_exitPoint);
}
 

protected Object _doEvaluate(XReturnExpression returnExpr, IEvaluationContext context, CancelIndicator indicator) {
	Object returnValue = internalEvaluate(returnExpr.getExpression(), context, indicator);
	throw new ReturnValue(returnValue);
}
 

/**
 * don't call this directly. Always call evaluate() internalEvaluate()
 */
protected Object doEvaluate(XExpression expression, IEvaluationContext context, CancelIndicator indicator) {
	if (expression instanceof XAssignment) {
      return _doEvaluate((XAssignment)expression, context, indicator);
    } else if (expression instanceof XDoWhileExpression) {
      return _doEvaluate((XDoWhileExpression)expression, context, indicator);
    } else if (expression instanceof XMemberFeatureCall) {
      return _doEvaluate((XMemberFeatureCall)expression, context, indicator);
    } else if (expression instanceof XWhileExpression) {
      return _doEvaluate((XWhileExpression)expression, context, indicator);
    } else if (expression instanceof XFeatureCall) {
    	return _doEvaluate((XFeatureCall)expression, context, indicator);
    } else if (expression instanceof XAbstractFeatureCall) {
    	return _doEvaluate((XAbstractFeatureCall)expression, context, indicator);
    } else if (expression instanceof XBlockExpression) {
      return _doEvaluate((XBlockExpression)expression, context, indicator);
    } else if (expression instanceof XSynchronizedExpression) {
	  return _doEvaluate((XSynchronizedExpression)expression, context, indicator);
	} else if (expression instanceof XBooleanLiteral) {
      return _doEvaluate((XBooleanLiteral)expression, context, indicator);
    } else if (expression instanceof XCastedExpression) {
      return _doEvaluate((XCastedExpression)expression, context, indicator);
    } else if (expression instanceof XClosure) {
      return _doEvaluate((XClosure)expression, context, indicator);
    } else if (expression instanceof XConstructorCall) {
      return _doEvaluate((XConstructorCall)expression, context, indicator);
    } else if (expression instanceof XForLoopExpression) {
      return _doEvaluate((XForLoopExpression)expression, context, indicator);
    } else if (expression instanceof XBasicForLoopExpression) {
	  return _doEvaluate((XBasicForLoopExpression)expression, context, indicator);
	} else if (expression instanceof XIfExpression) {
      return _doEvaluate((XIfExpression)expression, context, indicator);
    } else if (expression instanceof XInstanceOfExpression) {
      return _doEvaluate((XInstanceOfExpression)expression, context, indicator);
    } else if (expression instanceof XNullLiteral) {
      return _doEvaluate((XNullLiteral)expression, context, indicator);
    } else if (expression instanceof XNumberLiteral) {
      return _doEvaluate((XNumberLiteral)expression, context, indicator);
    } else if (expression instanceof XReturnExpression) {
      return _doEvaluate((XReturnExpression)expression, context, indicator);
    } else if (expression instanceof XStringLiteral) {
      return _doEvaluate((XStringLiteral)expression, context, indicator);
    } else if (expression instanceof XSwitchExpression) {
      return _doEvaluate((XSwitchExpression)expression, context, indicator);
    } else if (expression instanceof XThrowExpression) {
      return _doEvaluate((XThrowExpression)expression, context, indicator);
    } else if (expression instanceof XTryCatchFinallyExpression) {
      return _doEvaluate((XTryCatchFinallyExpression)expression, context, indicator);
    } else if (expression instanceof XTypeLiteral) {
      return _doEvaluate((XTypeLiteral)expression, context, indicator);
    } else if (expression instanceof XVariableDeclaration) {
	      return _doEvaluate((XVariableDeclaration)expression, context, indicator);
    } else if (expression instanceof XListLiteral) {
	      return _doEvaluate((XListLiteral)expression, context, indicator);
    } else if (expression instanceof XSetLiteral) {
	      return _doEvaluate((XSetLiteral)expression, context, indicator);
    } else {
      throw new IllegalArgumentException("Unhandled parameter types: " +
        Arrays.<Object>asList(expression, context, indicator).toString());
    }
}
 

@Override
protected boolean isVariableDeclarationRequired(XExpression expr, ITreeAppendable b, boolean recursive) {
	if (expr instanceof XAnnotation) {
		return false;
	}
	if (expr instanceof XListLiteral) {
		return false;
	}
	if (expr instanceof XSetLiteral) {
		return false;
	}
	if (expr instanceof XCastedExpression) {
		return false;
	}
	if (expr instanceof XInstanceOfExpression) {
		return false;
	}
	if (expr instanceof XMemberFeatureCall && isVariableDeclarationRequired((XMemberFeatureCall) expr, b))
		return true;
	EObject container = expr.eContainer();
	if ((container instanceof XVariableDeclaration)
		|| (container instanceof XReturnExpression) 
		|| (container instanceof XThrowExpression)) {
		return false;
	}
	if (container instanceof XIfExpression) {
		XIfExpression ifExpression = (XIfExpression) container;
		if (ifExpression.getThen() == expr || ifExpression.getElse() == expr) {
			return false;
		}
	}
	if (container instanceof XCasePart) {
		XCasePart casePart = (XCasePart) container;
		if (casePart.getThen() == expr) {
			return false;
		}
	}
	if (container instanceof XSwitchExpression) {
		XSwitchExpression switchExpression = (XSwitchExpression) container;
		if (switchExpression.getDefault() == expr) {
			return false;
		}
	}
	if (container instanceof XBlockExpression) {
		List<XExpression> siblings = ((XBlockExpression) container).getExpressions();
		if (siblings.get(siblings.size() - 1) == expr) {
			return isVariableDeclarationRequired(getFeatureCall(expr), expr, b);
		}
	}
	if (container instanceof XClosure) {
		if (((XClosure) container).getExpression() == expr) {
			return false;
		}
	}
	if (expr instanceof XAssignment) {
		XAssignment a = (XAssignment) expr;
		for (XExpression arg : getActualArguments(a)) {
			if (isVariableDeclarationRequired(arg, b, recursive)) {
				return true;
			}
		}
	}
	return super.isVariableDeclarationRequired(expr, b, recursive);
}
 

protected void _toJavaExpression(XReturnExpression returnExpression, ITreeAppendable b) {
	b.append("/* error - couldn't compile nested return */");
}
 

@Override
protected void doInternalToJavaStatement(XExpression obj, ITreeAppendable appendable, boolean isReferenced) {
	if (obj instanceof XBlockExpression) {
		_toJavaStatement((XBlockExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XCastedExpression) {
		_toJavaStatement((XCastedExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XClosure) {
		_toJavaStatement((XClosure) obj, appendable, isReferenced);
	} else if (obj instanceof XConstructorCall) {
		_toJavaStatement((XConstructorCall) obj, appendable, isReferenced);
	} else if (obj instanceof XDoWhileExpression) {
		_toJavaStatement((XDoWhileExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XForLoopExpression) {
		_toJavaStatement((XForLoopExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XBasicForLoopExpression) {
		_toJavaStatement((XBasicForLoopExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XIfExpression) {
		_toJavaStatement((XIfExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XInstanceOfExpression) {
		_toJavaStatement((XInstanceOfExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XReturnExpression) {
		_toJavaStatement((XReturnExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XSwitchExpression) {
		_toJavaStatement((XSwitchExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XThrowExpression) {
		_toJavaStatement((XThrowExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XTryCatchFinallyExpression) {
		_toJavaStatement((XTryCatchFinallyExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XVariableDeclaration) {
		_toJavaStatement((XVariableDeclaration) obj, appendable, isReferenced);
	} else if (obj instanceof XWhileExpression) {
		_toJavaStatement((XWhileExpression) obj, appendable, isReferenced);
	} else if (obj instanceof XListLiteral) {
		_toJavaStatement((XListLiteral) obj, appendable, isReferenced);
	} else if (obj instanceof XSetLiteral) {
		_toJavaStatement((XSetLiteral) obj, appendable, isReferenced);
	} else if (obj instanceof XSynchronizedExpression) {
		_toJavaStatement((XSynchronizedExpression) obj, appendable, isReferenced);
	} else {
		super.doInternalToJavaStatement(obj, appendable, isReferenced);
	}
}
 

public boolean isDefiniteEarlyExit(XExpression expression) {
	// TODO further improvements
	if (expression instanceof XIfExpression) {
		XIfExpression ifExpression = (XIfExpression) expression;
		return isDefiniteEarlyExit(ifExpression.getThen()) && isDefiniteEarlyExit(ifExpression.getElse());
	} else if (expression instanceof XSwitchExpression) {
		XSwitchExpression switchExpression = (XSwitchExpression) expression;
		if (isDefiniteEarlyExit(switchExpression.getDefault())) {
			for(XCasePart caseExpression: switchExpression.getCases()) {
				if (!isDefiniteEarlyExit(caseExpression.getThen())) {
					return false;
				}
			}
			return true;
		}
		return false;
	} else if (expression instanceof XTryCatchFinallyExpression) {
		XTryCatchFinallyExpression tryExpression = (XTryCatchFinallyExpression) expression;
		if (isDefiniteEarlyExit(tryExpression.getFinallyExpression())) {
			return true;
		}
		if (isDefiniteEarlyExit(tryExpression.getExpression())) {
			for(XCatchClause catchClause: tryExpression.getCatchClauses()) {
				if (!isDefiniteEarlyExit(catchClause.getExpression())) {
					return false;
				}
			}
			return true;
		}
		return false;
	} else if (expression instanceof XBlockExpression) {
		List<XExpression> expressions = ((XBlockExpression) expression).getExpressions();
		for(int i = expressions.size() - 1; i >= 0; i--) {
			if (isDefiniteEarlyExit(expressions.get(i))) {
				return true;
			}
		}
	} else if (expression instanceof XSynchronizedExpression) {
		return isDefiniteEarlyExit(((XSynchronizedExpression) expression).getExpression());
	}
	return expression instanceof XReturnExpression || expression instanceof XThrowExpression;
}