import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Override
protected void internalToConvertedExpression(XExpression obj, ITreeAppendable appendable) {
	if (obj instanceof XStringLiteral) {
		_toJavaExpression((XStringLiteral) obj, appendable);
	} else if (obj instanceof XNumberLiteral) {
		_toJavaExpression((XNumberLiteral) obj, appendable);
	} else if (obj instanceof XNullLiteral) {
		_toJavaExpression((XNullLiteral) obj, appendable);
	} else if (obj instanceof XBooleanLiteral) {
		_toJavaExpression((XBooleanLiteral) obj, appendable);
	} else if (obj instanceof XTypeLiteral) {
		_toJavaExpression((XTypeLiteral) obj, appendable);
	} else {
		super.internalToConvertedExpression(obj, appendable);
	}
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Override
protected void doInternalToJavaStatement(XExpression obj, ITreeAppendable appendable, boolean isReferenced) {
	if (obj instanceof XStringLiteral) {
		_toJavaStatement((XStringLiteral) obj, appendable, isReferenced);
	} else if (obj instanceof XNumberLiteral) {
		_toJavaStatement((XNumberLiteral) obj, appendable, isReferenced);
	} else if (obj instanceof XNullLiteral) {
		_toJavaStatement((XNullLiteral) obj, appendable, isReferenced);
	} else if (obj instanceof XBooleanLiteral) {
		_toJavaStatement((XBooleanLiteral) obj, appendable, isReferenced);
	} else if (obj instanceof XTypeLiteral) {
		_toJavaStatement((XTypeLiteral) obj, appendable, isReferenced);
	} else {
		super.doInternalToJavaStatement(obj, appendable, isReferenced);
	}
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
protected void appendImmutableCollectionExpression(XCollectionLiteral literal,
		ITreeAppendable b, String collectionsMethod, Class<?> guavaHelper, String guavaHelperMethod) {
	LightweightTypeReference collectionElementType = getCollectionElementType(literal);
	b.append(Collections.class);
	b.append(".<").append(collectionElementType).append(">").append(collectionsMethod).append("(");
	b.append(guavaHelper).append(".<").append(collectionElementType).append(">").append(guavaHelperMethod).append("(");
	boolean isFirst = true;
	for(XExpression element: literal.getElements())  {
		if(!isFirst)
			b.append(", ");
		isFirst = false;
		if(element instanceof XNullLiteral) {
			b.append("(").append(collectionElementType).append(")");
		}
		internalToJavaExpression(element, b);
	}
	b.append("))");
	return;
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Test
public void testChildrenAddEntryForParent() {
  try {
    this.resolver.setTypeComputer(this);
    final XExpression expression = this.expression("{ null }");
    this.resolver.initializeFrom(expression);
    final PublicResolvedTypes resolution = new PublicResolvedTypes(this.resolver);
    final AnyTypeReference any = resolution.getReferenceOwner().newAnyTypeReference();
    IFeatureScopeSession _newSession = this.resolver.getBatchScopeProvider().newSession(expression.eResource());
    new ExpressionBasedRootTypeComputationState(resolution, _newSession, expression, any).computeTypes();
    Assert.assertEquals(any.toString(), resolution.getActualType(expression).toString());
    EObject _head = IterableExtensions.<EObject>head(expression.eContents());
    Assert.assertEquals(any.toString(), resolution.getActualType(((XNullLiteral) _head)).toString());
  } catch (Throwable _e) {
    throw Exceptions.sneakyThrow(_e);
  }
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
/**
 * @return whether the expression itself (not its children) possibly causes a side-effect
 */
public boolean hasSideEffects(XExpression expr) {
	if (expr instanceof XClosure
		|| expr instanceof XStringLiteral
		|| expr instanceof XTypeLiteral
		|| expr instanceof XBooleanLiteral
		|| expr instanceof XNumberLiteral
		|| expr instanceof XNullLiteral
		|| expr instanceof XAnnotation
		)
		return false;
	if(expr instanceof XCollectionLiteral) {
		for(XExpression element: ((XCollectionLiteral)expr).getElements()) {
			if(hasSideEffects(element))
				return true;
		}
		return false;
	}
	if (expr instanceof XAbstractFeatureCall) {
		XAbstractFeatureCall featureCall = (XAbstractFeatureCall) expr;
		return hasSideEffects(featureCall, true);
	}
	if (expr instanceof XConstructorCall) {
		XConstructorCall constrCall = (XConstructorCall) expr;
		return findPureAnnotation(constrCall.getConstructor()) == null;
	}
	return true;
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Override
protected boolean isVariableDeclarationRequired(XExpression expr, ITreeAppendable b, boolean recursive) {
	if (expr instanceof XBooleanLiteral
		|| expr instanceof XStringLiteral
		|| expr instanceof XNumberLiteral
		|| expr instanceof XTypeLiteral
		|| expr instanceof XClosure
		|| expr instanceof XNullLiteral)
		return false;
	return super.isVariableDeclarationRequired(expr,b, recursive);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
public EvaluationResult internalEvaluate(final XExpression it, final EvaluationContext context) {
  if (it instanceof XBinaryOperation) {
    return _internalEvaluate((XBinaryOperation)it, context);
  } else if (it instanceof XUnaryOperation) {
    return _internalEvaluate((XUnaryOperation)it, context);
  } else if (it instanceof XAbstractFeatureCall) {
    return _internalEvaluate((XAbstractFeatureCall)it, context);
  } else if (it instanceof XBooleanLiteral) {
    return _internalEvaluate((XBooleanLiteral)it, context);
  } else if (it instanceof XCastedExpression) {
    return _internalEvaluate((XCastedExpression)it, context);
  } else if (it instanceof XNullLiteral) {
    return _internalEvaluate((XNullLiteral)it, context);
  } else if (it instanceof XNumberLiteral) {
    return _internalEvaluate((XNumberLiteral)it, context);
  } else if (it instanceof XStringLiteral) {
    return _internalEvaluate((XStringLiteral)it, context);
  } else if (it instanceof XTypeLiteral) {
    return _internalEvaluate((XTypeLiteral)it, context);
  } else if (it != null) {
    return _internalEvaluate(it, context);
  } else if (it == null) {
    return _internalEvaluate((Void)null, context);
  } else {
    throw new IllegalArgumentException("Unhandled parameter types: " +
      Arrays.<Object>asList(it, context).toString());
  }
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Override
public void computeTypes(final XExpression expression, final ITypeComputationState state) {
  try {
    Assert.assertTrue("state is instanceof ExpressionTypeComputationState", (state instanceof ExpressionTypeComputationState));
    final LightweightTypeReference expectedType = IterableExtensions.head(state.getExpectations()).getExpectedType();
    if ((expression instanceof XNullLiteral)) {
      final ExpressionTypeComputationState casted = ((ExpressionTypeComputationState) state);
      final ResolvedTypes resolution = this._reflectExtensions.<ResolvedTypes>get(casted, "resolvedTypes");
      final ResolvedTypes parentResolution = this._reflectExtensions.<ResolvedTypes>get(this._reflectExtensions.<ExpressionTypeComputationState>get(casted, "parent"), "resolvedTypes");
      EObject _eContainer = ((XNullLiteral)expression).eContainer();
      Assert.assertNull(parentResolution.getActualType(((XExpression) _eContainer)));
      state.acceptActualType(expectedType);
      Assert.assertNull(parentResolution.getActualType(expression));
      Assert.assertEquals(expectedType.getIdentifier(), resolution.getActualType(expression).getIdentifier());
      EObject _eContainer_1 = ((XNullLiteral)expression).eContainer();
      Assert.assertNull(parentResolution.getActualType(((XExpression) _eContainer_1)));
    } else {
      Assert.assertTrue((expression instanceof XBlockExpression));
      EObject _head = IterableExtensions.<EObject>head(expression.eContents());
      final XNullLiteral nullLiteral = ((XNullLiteral) _head);
      state.computeTypes(nullLiteral);
      final ResolvedTypes resolution_1 = this._reflectExtensions.<ResolvedTypes>get(state, "resolvedTypes");
      Assert.assertEquals(expectedType.getIdentifier(), resolution_1.getActualType(nullLiteral).getIdentifier());
    }
  } catch (Throwable _e) {
    throw Exceptions.sneakyThrow(_e);
  }
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
protected <T extends Object> void genericTestInitializeSafely(final Function3<? super EObject, ? super String, ? super Procedure1<? super T>, ? extends EObject> create) {
  final XNullLiteral expr = XbaseFactory.eINSTANCE.createXNullLiteral();
  final Wrapper<Boolean> initialized = new Wrapper<Boolean>(Boolean.valueOf(false));
  final Procedure1<T> _function = (T it) -> {
    initialized.set(Boolean.valueOf(true));
    throw new RuntimeException();
  };
  final EObject element = create.apply(expr, "foo", _function);
  Assert.assertTrue((initialized.get()).booleanValue());
  Assert.assertNotNull(element);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Deprecated
protected void sequence_XNullLiteral(EObject context, XNullLiteral semanticObject) {
	sequence_XNullLiteral(createContext(context, semanticObject), semanticObject);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
@Override
public void computeTypes(XExpression expression, ITypeComputationState state) {
	if (expression instanceof XAssignment) {
		_computeTypes((XAssignment)expression, state);
	} else if (expression instanceof XAbstractFeatureCall) {
		_computeTypes((XAbstractFeatureCall)expression, state);
	} else if (expression instanceof XDoWhileExpression) {
		_computeTypes((XDoWhileExpression)expression, state);
	} else if (expression instanceof XWhileExpression) {
		_computeTypes((XWhileExpression)expression, state);
	} else if (expression instanceof XBlockExpression) {
		_computeTypes((XBlockExpression)expression, state);
	} else if (expression instanceof XBooleanLiteral) {
		_computeTypes((XBooleanLiteral)expression, state);
	} else if (expression instanceof XCastedExpression) {
		_computeTypes((XCastedExpression)expression, state);
	} else if (expression instanceof XClosure) {
		_computeTypes((XClosure)expression, state);
	} else if (expression instanceof XConstructorCall) {
		_computeTypes((XConstructorCall)expression, state);
	} else if (expression instanceof XForLoopExpression) {
		_computeTypes((XForLoopExpression)expression, state);
	} else if (expression instanceof XBasicForLoopExpression) {
		_computeTypes((XBasicForLoopExpression)expression, state);
	} else if (expression instanceof XIfExpression) {
		_computeTypes((XIfExpression)expression, state);
	} else if (expression instanceof XInstanceOfExpression) {
		_computeTypes((XInstanceOfExpression)expression, state);
	} else if (expression instanceof XNumberLiteral) {
		_computeTypes((XNumberLiteral)expression, state);
	} else if (expression instanceof XNullLiteral) {
		_computeTypes((XNullLiteral)expression, state);
	} else if (expression instanceof XReturnExpression) {
		_computeTypes((XReturnExpression)expression, state);
	} else if (expression instanceof XStringLiteral) {
		_computeTypes((XStringLiteral)expression, state);
	} else if (expression instanceof XSwitchExpression) {
		_computeTypes((XSwitchExpression)expression, state);
	} else if (expression instanceof XThrowExpression) {
		_computeTypes((XThrowExpression)expression, state);
	} else if (expression instanceof XTryCatchFinallyExpression) {
		_computeTypes((XTryCatchFinallyExpression)expression, state);
	} else if (expression instanceof XTypeLiteral) {
		_computeTypes((XTypeLiteral)expression, state);
	} else if (expression instanceof XVariableDeclaration) {
		_computeTypes((XVariableDeclaration)expression, state);
	} else if (expression instanceof XListLiteral) {
		_computeTypes((XListLiteral)expression, state);
	} else if (expression instanceof XSetLiteral) {
		_computeTypes((XSetLiteral)expression, state);
	} else if (expression instanceof XSynchronizedExpression) {
		_computeTypes((XSynchronizedExpression)expression, state);
	} else {
		throw new UnsupportedOperationException("Missing type computation for expression type: " + expression.eClass().getName() + " / " + state);
	}
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
/**
 * @param object used for dispatching
 */
protected void _computeTypes(XNullLiteral object, ITypeComputationState state) {
	state.acceptActualType(state.getReferenceOwner().newAnyTypeReference());
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
/**
 * This is for backwards compatibility < 2.3RC2 due to change in the naming strategy for sequencer methods
 */
@Deprecated
protected void sequence_XExpression(EObject context, XNullLiteral semanticObject) {
	super.sequence_XNullLiteral(context, semanticObject);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
/**
 * @param expr the expression. Used by the dispatch strategy.
 */
public void _toJavaExpression(XNullLiteral expr, ITreeAppendable b) {
	b.append("null");
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
public void _toJavaStatement(XNullLiteral expr, ITreeAppendable b, boolean isReferenced) {
	generateComment(expr, b, isReferenced);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
/**
 * 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());
    }
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
protected void _findImplicitReturns(final XNullLiteral expression, final ImplicitReturnFinder.Acceptor acceptor) {
  acceptor.accept(expression);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
public void findImplicitReturns(final XExpression expression, final ImplicitReturnFinder.Acceptor acceptor) {
  if (expression instanceof XAbstractFeatureCall) {
    _findImplicitReturns((XAbstractFeatureCall)expression, acceptor);
    return;
  } else if (expression instanceof XBlockExpression) {
    _findImplicitReturns((XBlockExpression)expression, acceptor);
    return;
  } else if (expression instanceof XBooleanLiteral) {
    _findImplicitReturns((XBooleanLiteral)expression, acceptor);
    return;
  } else if (expression instanceof XCastedExpression) {
    _findImplicitReturns((XCastedExpression)expression, acceptor);
    return;
  } else if (expression instanceof XClosure) {
    _findImplicitReturns((XClosure)expression, acceptor);
    return;
  } else if (expression instanceof XCollectionLiteral) {
    _findImplicitReturns((XCollectionLiteral)expression, acceptor);
    return;
  } else if (expression instanceof XConstructorCall) {
    _findImplicitReturns((XConstructorCall)expression, acceptor);
    return;
  } else if (expression instanceof XIfExpression) {
    _findImplicitReturns((XIfExpression)expression, acceptor);
    return;
  } else if (expression instanceof XInstanceOfExpression) {
    _findImplicitReturns((XInstanceOfExpression)expression, acceptor);
    return;
  } else if (expression instanceof XNullLiteral) {
    _findImplicitReturns((XNullLiteral)expression, acceptor);
    return;
  } else if (expression instanceof XNumberLiteral) {
    _findImplicitReturns((XNumberLiteral)expression, acceptor);
    return;
  } else if (expression instanceof XStringLiteral) {
    _findImplicitReturns((XStringLiteral)expression, acceptor);
    return;
  } else if (expression instanceof XSwitchExpression) {
    _findImplicitReturns((XSwitchExpression)expression, acceptor);
    return;
  } else if (expression instanceof XSynchronizedExpression) {
    _findImplicitReturns((XSynchronizedExpression)expression, acceptor);
    return;
  } else if (expression instanceof XTryCatchFinallyExpression) {
    _findImplicitReturns((XTryCatchFinallyExpression)expression, acceptor);
    return;
  } else if (expression instanceof XTypeLiteral) {
    _findImplicitReturns((XTypeLiteral)expression, acceptor);
    return;
  } else if (expression != null) {
    _findImplicitReturns(expression, acceptor);
    return;
  } else if (expression == null) {
    _findImplicitReturns((Void)null, acceptor);
    return;
  } else {
    throw new IllegalArgumentException("Unhandled parameter types: " +
      Arrays.<Object>asList(expression, acceptor).toString());
  }
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
protected EvaluationResult _internalEvaluate(final XNullLiteral it, final EvaluationContext context) {
  return new EvaluationResult(null, true);
}
 

import org.eclipse.xtext.xbase.XNullLiteral; //导入依赖的package包/类
/**
 * @param literal unused in this context but required for dispatching 
 * @param context unused in this context but required for dispatching
 * @param indicator unused in this context but required for dispatching
 */
protected Object _doEvaluate(XNullLiteral literal, IEvaluationContext context, CancelIndicator indicator) {
	return null;
}