@Nullable
 private static PsiType getInferredTypes(
     GrReferenceExpressionImpl refExpr, @Nullable PsiElement resolved) {
   final GrExpression qualifier = refExpr.getQualifier();
   if (qualifier == null && !(resolved instanceof PsiClass)) {
     return TypeInferenceHelper.getCurrentContext().getVariableType(refExpr);
   } else if (qualifier != null) {
     // map access
     PsiType qType = qualifier.getType();
     if (qType instanceof PsiClassType && !(qType instanceof GrMapType)) {
       PsiClassType.ClassResolveResult qResult = ((PsiClassType) qType).resolveGenerics();
       PsiClass clazz = qResult.getElement();
       if (clazz != null) {
         PsiClass mapClass =
             JavaPsiFacade.getInstance(refExpr.getProject())
                 .findClass(CommonClassNames.JAVA_UTIL_MAP, refExpr.getResolveScope());
         if (mapClass != null && mapClass.getTypeParameters().length == 2) {
           PsiSubstitutor substitutor =
               TypeConversionUtil.getClassSubstitutor(mapClass, clazz, qResult.getSubstitutor());
           if (substitutor != null) {
             return TypeConversionUtil.erasure(
                 substitutor.substitute(mapClass.getTypeParameters()[1]));
           }
         }
       }
     }
   }
   return null;
 }
 public void visitAssignmentExpression(GrAssignmentExpression expression) {
   GrExpression rValue = expression.getRValue();
   GrExpression lValue = expression.getLValue();
   if (myExpression.equals(rValue)) {
     PsiType lType = lValue.getNominalType();
     if (lType != null) {
       myResult = new TypeConstraint[] {SubtypeConstraint.create(lType)};
     } else if (lValue instanceof GrReferenceExpression) {
       GroovyResolveResult result = ((GrReferenceExpression) lValue).advancedResolve();
       PsiElement resolved = result.getElement();
       if (resolved instanceof GrVariable) {
         PsiType type = ((GrVariable) resolved).getTypeGroovy();
         if (type != null) {
           myResult =
               new TypeConstraint[] {
                 SubtypeConstraint.create(result.getSubstitutor().substitute(type))
               };
         }
       }
     }
   } else if (myExpression.equals(lValue)) {
     if (rValue != null) {
       PsiType rType = rValue.getType();
       if (rType != null) {
         myResult = new TypeConstraint[] {SupertypeConstraint.create(rType)};
       }
     }
   }
 }
    @Override
    public void visitBinaryExpression(GrBinaryExpression expression) {
      final IElementType type = expression.getOperationTokenType();
      final GrExpression left = expression.getLeftOperand();
      final GrExpression right = expression.getRightOperand();

      if (type == mREGEX_FIND || type == mREGEX_MATCH) {
        final PsiClassType string =
            TypesUtil.createType(CommonClassNames.JAVA_LANG_STRING, expression);
        myResult = createSimpleSubTypeResult(string);
        return;
      }

      final GrExpression other = myExpression == left ? right : left;
      final PsiType otherType = other != null ? other.getType() : null;

      if (otherType == null) return;

      if (type == mPLUS && otherType.equalsToText(CommonClassNames.JAVA_LANG_STRING)) {
        final PsiClassType obj = TypesUtil.getJavaLangObject(expression);
        myResult = createSimpleSubTypeResult(obj);
        return;
      }

      myResult = createSimpleSubTypeResult(otherType);
    }
 @Nullable
 private static PsiType getNominalTypeNoRecursion(@NotNull final GrExpression expression) {
   if (expression instanceof GrNewExpression) {
     return expression.getType();
   } else if (expression instanceof GrReferenceExpression
       && ((GrReferenceExpression) expression).getQualifier() == null) {
     return getTypeByRef((GrReferenceExpression) expression);
   }
   return null;
 }
    @Override
    public void visitCaseLabel(GrCaseLabel caseLabel) {
      final PsiElement parent = caseLabel.getParent().getParent();
      assert parent instanceof GrSwitchStatement : parent + " of class " + parent.getClass();
      final GrExpression condition = ((GrSwitchStatement) parent).getCondition();
      if (condition == null) return;

      final PsiType type = condition.getType();
      if (type == null) return;

      myResult = new TypeConstraint[] {SubtypeConstraint.create(type)};
    }
    @Override
    public void visitSwitchStatement(GrSwitchStatement switchStatement) {
      final GrCaseSection[] sections = switchStatement.getCaseSections();
      List<PsiType> types = new ArrayList<PsiType>(sections.length);
      for (GrCaseSection section : sections) {
        final GrExpression value = section.getCaseLabel().getValue();
        final PsiType type = value != null ? value.getType() : null;
        if (type != null) types.add(type);
      }

      final PsiType upperBoundNullable =
          TypesUtil.getLeastUpperBoundNullable(types, switchStatement.getManager());
      if (upperBoundNullable == null) return;

      myResult = new TypeConstraint[] {SubtypeConstraint.create(upperBoundNullable)};
    }
  private boolean isDefinitelyKeyOfMap() {
    final GrExpression qualifier = ResolveUtil.getSelfOrWithQualifier(this);
    if (qualifier == null) return false;
    if (qualifier
        instanceof
        GrReferenceExpression) { // key in 'java.util.Map.key' is not access to map, it is access to
      // static property of field
      final PsiElement resolved = ((GrReferenceExpression) qualifier).resolve();
      if (resolved instanceof PsiClass) return false;
    }

    final PsiType type = qualifier.getType();
    if (type == null) return false;

    if (!InheritanceUtil.isInheritor(type, CommonClassNames.JAVA_UTIL_MAP)) return false;

    final String canonicalText = type.getCanonicalText();
    if (canonicalText.startsWith("java.")) return true;
    if (GroovyCommonClassNames.GROOVY_UTIL_CONFIG_OBJECT.equals(canonicalText)) return false;
    if (canonicalText.startsWith("groovy.")) return true;

    return false;
  }
    @Nullable
    public PsiType fun(GrReferenceExpressionImpl refExpr) {
      PsiType result = GrReassignedLocalVarsChecker.checkReassignedVar(refExpr, true);
      if (result != null) return result;

      if (GrUnresolvedAccessInspection.isClassReference(refExpr)) {
        GrExpression qualifier = refExpr.getQualifier();
        LOG.assertTrue(qualifier != null);
        return TypesUtil.createJavaLangClassType(
            qualifier.getType(), refExpr.getProject(), refExpr.getResolveScope());
      }

      final PsiElement resolved = refExpr.resolve();
      final PsiType inferred = getInferredTypes(refExpr, resolved);
      final PsiType nominal = refExpr.getNominalType();
      if (inferred == null || PsiType.NULL.equals(inferred)) {
        if (nominal == null) {
          // inside nested closure we could still try to infer from variable initializer. Not sound,
          // but makes sense
          if (resolved instanceof GrVariable) {
            LOG.assertTrue(resolved.isValid());
            return ((GrVariable) resolved).getTypeGroovy();
          }
        }

        return nominal;
      }

      if (nominal == null) return inferred;
      if (!TypeConversionUtil.isAssignable(TypeConversionUtil.erasure(nominal), inferred, false)) {
        if (resolved instanceof GrVariable
            && ((GrVariable) resolved).getTypeElementGroovy() != null) {
          return nominal;
        }
      }
      return inferred;
    }
  private static boolean shouldHighlightAsUnresolved(
      @NotNull GrReferenceExpression referenceExpression) {
    if (GrHighlightUtil.isDeclarationAssignment(referenceExpression)) return false;

    GrExpression qualifier = referenceExpression.getQualifier();
    if (qualifier != null && qualifier.getType() == null && !isRefToPackage(qualifier))
      return false;

    if (qualifier != null
        && referenceExpression.getDotTokenType() == GroovyTokenTypes.mMEMBER_POINTER
        && referenceExpression.multiResolve(false).length > 0) {
      return false;
    }

    if (!GroovyUnresolvedHighlightFilter.shouldHighlight(referenceExpression)) return false;

    CollectConsumer<PomTarget> consumer = new CollectConsumer<PomTarget>();
    for (PomDeclarationSearcher searcher : PomDeclarationSearcher.EP_NAME.getExtensions()) {
      searcher.findDeclarationsAt(referenceExpression, 0, consumer);
      if (!consumer.getResult().isEmpty()) return false;
    }

    return true;
  }
  @Nullable
  private PsiType getNominalTypeInner(PsiElement resolved) {
    if (resolved == null && !"class".equals(getReferenceName())) {
      resolved = resolve();
    }

    if (resolved instanceof PsiClass) {
      final PsiElementFactory factory = JavaPsiFacade.getInstance(getProject()).getElementFactory();
      if (PsiUtil.isInstanceThisRef(this)) {
        final PsiClassType categoryType = GdkMethodUtil.getCategoryType((PsiClass) resolved);
        if (categoryType != null) {
          return categoryType;
        } else {
          return factory.createType((PsiClass) resolved);
        }
      }
      if (getParent() instanceof GrReferenceExpression || PsiUtil.isSuperReference(this)) {
        return factory.createType((PsiClass) resolved);
      } else {
        return TypesUtil.createJavaLangClassType(
            factory.createType((PsiClass) resolved), getProject(), getResolveScope());
      }
    }

    if (resolved instanceof GrVariable) {
      return ((GrVariable) resolved).getDeclaredType();
    }

    if (resolved instanceof PsiVariable) {
      return ((PsiVariable) resolved).getType();
    }

    if (resolved instanceof PsiMethod) {
      PsiMethod method = (PsiMethod) resolved;
      if (PropertyUtil.isSimplePropertySetter(method)
          && !method.getName().equals(getReferenceName())) {
        return method.getParameterList().getParameters()[0].getType();
      }

      // 'class' property with explicit generic
      PsiClass containingClass = method.getContainingClass();
      if (containingClass != null
          && CommonClassNames.JAVA_LANG_OBJECT.equals(containingClass.getQualifiedName())
          && "getClass".equals(method.getName())) {
        return TypesUtil.createJavaLangClassType(
            GrReferenceResolveUtil.getQualifierType(this), getProject(), getResolveScope());
      }

      return PsiUtil.getSmartReturnType(method);
    }

    if (resolved instanceof GrReferenceExpression) {
      PsiElement parent = resolved.getParent();
      if (parent instanceof GrAssignmentExpression) {
        GrAssignmentExpression assignment = (GrAssignmentExpression) parent;
        if (resolved.equals(assignment.getLValue())) {
          GrExpression rValue = assignment.getRValue();
          if (rValue != null) {
            PsiType rType = rValue.getType();
            if (rType != null) {
              return rType;
            }
          }
        }
      }
    }

    if (resolved == null) {
      final PsiType fromClassRef = getTypeFromClassRef(this);
      if (fromClassRef != null) {
        return fromClassRef;
      }

      final PsiType fromMapAccess = getTypeFromMapAccess(this);
      if (fromMapAccess != null) {
        return fromMapAccess;
      }

      final PsiType fromSpreadOperator = getTypeFromSpreadOperator(this);
      if (fromSpreadOperator != null) {
        return fromSpreadOperator;
      }
    }

    return null;
  }