render not inferred return/parameter type of function literals as ???

instead of DONT_CARE / CANT_INFER

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ClosureExpressionsTypingVisitor.java

@@ -39,6 +39,7 @@ import java.util.List;
 import static org.jetbrains.jet.lang.diagnostics.Errors.*;
 import static org.jetbrains.jet.lang.resolve.BindingContext.*;
 import static org.jetbrains.jet.lang.types.TypeUtils.NO_EXPECTED_TYPE;
+import static org.jetbrains.jet.lang.types.expressions.ExpressionTypingUtils.CANNOT_BE_INFERRED;
 
 public class ClosureExpressionsTypingVisitor extends ExpressionTypingVisitor {
     protected ClosureExpressionsTypingVisitor(@NotNull ExpressionTypingInternals facade) {
@@ -224,7 +225,7 @@ public class ClosureExpressionsTypingVisitor extends ExpressionTypingVisitor {
                 type = expectedType;
             }
             else {
-                type = ErrorUtils.createErrorType("Cannot be inferred");
+                type = CANNOT_BE_INFERRED;
             }
         }
         return context.expressionTypingServices.getDescriptorResolver().resolveValueParameterDescriptor(
@@ -255,7 +256,7 @@ public class ClosureExpressionsTypingVisitor extends ExpressionTypingVisitor {
                 return KotlinBuiltIns.getInstance().getUnitType();
             }
         }
-        return returnType == null ? ErrorUtils.createErrorType("<return type>") : returnType;
+        return returnType == null ? CANNOT_BE_INFERRED : returnType;
     }
 
     @Nullable

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/ExpressionTypingUtils.java

@@ -62,6 +62,8 @@ public class ExpressionTypingUtils {
     private ExpressionTypingUtils() {
     }
 
+    public static final JetType CANNOT_BE_INFERRED = ErrorUtils.createErrorType("Cannot be inferred");
+
     @Nullable
     protected static ExpressionReceiver getExpressionReceiver(@NotNull JetExpression expression, @Nullable JetType type) {
         if (type == null) return null;

compiler/frontend/src/org/jetbrains/jet/renderer/DescriptorRendererImpl.java

@@ -25,11 +25,11 @@ import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.descriptors.annotations.Annotated;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
-import org.jetbrains.jet.lang.resolve.calls.CallResolverUtil;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.FqNameUnsafe;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lang.types.*;
+import org.jetbrains.jet.lang.types.expressions.ExpressionTypingUtils;
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 import org.jetbrains.jet.lexer.JetKeywordToken;
 import org.jetbrains.jet.lexer.JetTokens;
@@ -194,12 +194,9 @@ public class DescriptorRendererImpl implements DescriptorRenderer {
     }
 
     private String renderTypeWithoutEscape(@NotNull JetType type) {
-        if (type == CallResolverUtil.DONT_CARE || type == CallResolverUtil.CANT_INFER) {
+        if (type == ExpressionTypingUtils.CANNOT_BE_INFERRED) {
             return "???";
         }
-        else if (type == CallResolverUtil.PLACEHOLDER_FUNCTION_TYPE) {
-            return "??? " + arrow() + " ???";
-        }
         else if (ErrorUtils.isErrorType(type)) {
             return type.toString();
         }

idea/testData/diagnosticMessage/functionPlaceholder1.html

@@ -36,7 +36,7 @@ cannot be applied to</td>
 <td align="right" style="white-space:nowrap;">
 <font color=red>
 <b>
-??? &rarr; ???</b>
+() &rarr; ???</b>
 </font>
 </td>
 <td style="white-space:nowrap;">

idea/testData/diagnosticMessage/functionPlaceholder3.html

@@ -36,7 +36,7 @@ cannot be applied to</td>
 <td align="right" style="white-space:nowrap;">
 <font color=red>
 <b>
-(jet.Int) &rarr; ???</b>
+(jet.Int) &rarr; jet.Int</b>
 </font>
 </td>
 <td style="white-space:nowrap;">