Parser: allow names to be specified for class objects

compiler/frontend/src/org/jetbrains/kotlin/parsing/JetExpressionParsing.java

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.JetNodeType;
 import org.jetbrains.kotlin.JetNodeTypes;
 import org.jetbrains.kotlin.lexer.JetToken;
 import org.jetbrains.kotlin.lexer.JetTokens;
+import org.jetbrains.kotlin.parsing.JetParsing.NameParsingMode;
 
 import java.util.Arrays;
 import java.util.HashSet;
@@ -1318,7 +1319,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
                 return null;
             }
 
-            myJetParsing.parseObject(true, true);
+            myJetParsing.parseObject(NameParsingMode.REQUIRED, true);
             declType = OBJECT_DECLARATION;
         }
         return declType;
@@ -1826,7 +1827,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
     public void parseObjectLiteral() {
         PsiBuilder.Marker literal = mark();
         PsiBuilder.Marker declaration = mark();
-        myJetParsing.parseObject(false, false); // Body is not optional because of foo(object : A, B)
+        myJetParsing.parseObject(NameParsingMode.PROHIBITED, false); // Body is not optional because of foo(object : A, B)
         declaration.done(OBJECT_DECLARATION);
         literal.done(OBJECT_LITERAL);
     }

compiler/frontend/src/org/jetbrains/kotlin/parsing/JetParsing.java

@@ -376,7 +376,7 @@ public class JetParsing extends AbstractJetParsing {
             declType = parseTypeAlias();
         }
         else if (keywordToken == OBJECT_KEYWORD) {
-            parseObject(true, true);
+            parseObject(NameParsingMode.REQUIRED, true);
             declType = OBJECT_DECLARATION;
         }
 
@@ -551,6 +551,12 @@ public class JetParsing extends AbstractJetParsing {
         annotation.done(ANNOTATION_ENTRY);
     }
 
+    public enum NameParsingMode {
+        REQUIRED,
+        ALLOWED,
+        PROHIBITED;
+    }
+
     /*
      * class
      *   : modifiers ("class" | "trait") SimpleName
@@ -565,7 +571,7 @@ public class JetParsing extends AbstractJetParsing {
      *   : "object" SimpleName? ":" delegationSpecifier{","}? classBody?
      *   ;
      */
-    IElementType parseClassOrObject(final boolean object, boolean named, boolean optionalBody, boolean enumClass) {
+    IElementType parseClassOrObject(boolean object, NameParsingMode nameParsingMode, boolean optionalBody, boolean enumClass) {
         if (object) {
             assert _at(OBJECT_KEYWORD);
         }
@@ -574,15 +580,23 @@ public class JetParsing extends AbstractJetParsing {
         }
         advance(); // CLASS_KEYWORD, TRAIT_KEYWORD or OBJECT_KEYWORD
 
-        if (named) {
+        if (nameParsingMode == NameParsingMode.REQUIRED) {
             OptionalMarker marker = new OptionalMarker(object);
             expect(IDENTIFIER, "Name expected", CLASS_NAME_RECOVERY_SET);
             marker.done(OBJECT_DECLARATION_NAME);
         }
         else {
+            assert object : "Must be an object to be nameless";
             if (at(IDENTIFIER)) {
-                assert object : "Must be an object to be nameless";
+                if (nameParsingMode == NameParsingMode.PROHIBITED) {
-                errorAndAdvance("An object expression cannot bind a name");
+                    errorAndAdvance("An object expression cannot bind a name");
+                }
+                else {
+                    assert nameParsingMode == NameParsingMode.ALLOWED;
+                    PsiBuilder.Marker marker = mark();
+                    advance();
+                    marker.done(OBJECT_DECLARATION_NAME);
+                }
             }
         }
 
@@ -595,7 +609,7 @@ public class JetParsing extends AbstractJetParsing {
         boolean hasConstructorModifiers = parseModifierList(PRIMARY_CONSTRUCTOR_MODIFIER_LIST, REGULAR_ANNOTATIONS_ONLY_WITH_BRACKETS);
 
         // Some modifiers found, but no parentheses following: class has already ended, and we are looking at something else
-        if (hasConstructorModifiers && !atSet(LPAR, LBRACE, COLON) ) {
+        if (hasConstructorModifiers && !atSet(LPAR, LBRACE, COLON)) {
             beforeConstructorModifiers.rollbackTo();
             constructorModifiersMarker.drop();
             return object ? OBJECT_DECLARATION : CLASS;
@@ -616,7 +630,7 @@ public class JetParsing extends AbstractJetParsing {
         }
         constructorModifiersMarker.error("Constructors are not allowed for objects");
 
-        if (at(COLON) ) {
+        if (at(COLON)) {
             advance(); // COLON
             parseDelegationSpecifierList();
         }
@@ -643,11 +657,11 @@ public class JetParsing extends AbstractJetParsing {
     }
 
     IElementType parseClass(boolean enumClass) {
-        return parseClassOrObject(false, true, true, enumClass);
+        return parseClassOrObject(false, NameParsingMode.REQUIRED, true, enumClass);
     }
 
-    void parseObject(boolean named, boolean optionalBody) {
+    void parseObject(NameParsingMode nameParsingMode, boolean optionalBody) {
-        parseClassOrObject(true, named, optionalBody, false);
+        parseClassOrObject(true, nameParsingMode, optionalBody, false);
     }
 
     /*
@@ -803,7 +817,7 @@ public class JetParsing extends AbstractJetParsing {
             declType = parseTypeAlias();
         }
         else if (keywordToken == OBJECT_KEYWORD) {
-            parseObject(true, true);
+            parseObject(NameParsingMode.REQUIRED, true);
             declType = OBJECT_DECLARATION;
         }
         else if (keywordToken == LBRACE) {
@@ -872,7 +886,7 @@ public class JetParsing extends AbstractJetParsing {
         advance(); // CLASS_KEYWORD
 
         PsiBuilder.Marker objectDeclaration = mark();
-        parseObject(false, true);
+        parseObject(NameParsingMode.ALLOWED, true);
         closeDeclarationWithCommentBinders(objectDeclaration, OBJECT_DECLARATION, true);
         return CLASS_OBJECT;
     }

compiler/testData/psi/NamedClassObject.kt

@@ -0,0 +1,11 @@
+class A {
+    class object Default
+
+    class object B
+
+    class object C {}
+
+    class object
+
+    object C
+}

compiler/testData/psi/NamedClassObject.txt

@@ -0,0 +1,55 @@
+JetFile: NamedClassObject.kt
+  PACKAGE_DIRECTIVE
+    <empty list>
+  CLASS
+    PsiElement(class)('class')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('A')
+    PsiWhiteSpace(' ')
+    CLASS_BODY
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      CLASS_OBJECT
+        PsiElement(class)('class')
+        PsiWhiteSpace(' ')
+        OBJECT_DECLARATION
+          PsiElement(object)('object')
+          PsiWhiteSpace(' ')
+          OBJECT_DECLARATION_NAME
+            PsiElement(IDENTIFIER)('Default')
+      PsiWhiteSpace('\n\n    ')
+      CLASS_OBJECT
+        PsiElement(class)('class')
+        PsiWhiteSpace(' ')
+        OBJECT_DECLARATION
+          PsiElement(object)('object')
+          PsiWhiteSpace(' ')
+          OBJECT_DECLARATION_NAME
+            PsiElement(IDENTIFIER)('B')
+      PsiWhiteSpace('\n\n    ')
+      CLASS_OBJECT
+        PsiElement(class)('class')
+        PsiWhiteSpace(' ')
+        OBJECT_DECLARATION
+          PsiElement(object)('object')
+          PsiWhiteSpace(' ')
+          OBJECT_DECLARATION_NAME
+            PsiElement(IDENTIFIER)('C')
+          PsiWhiteSpace(' ')
+          CLASS_BODY
+            PsiElement(LBRACE)('{')
+            PsiElement(RBRACE)('}')
+      PsiWhiteSpace('\n\n    ')
+      CLASS_OBJECT
+        PsiElement(class)('class')
+        PsiWhiteSpace(' ')
+        OBJECT_DECLARATION
+          PsiElement(object)('object')
+      PsiWhiteSpace('\n\n    ')
+      OBJECT_DECLARATION
+        PsiElement(object)('object')
+        PsiWhiteSpace(' ')
+        OBJECT_DECLARATION_NAME
+          PsiElement(IDENTIFIER)('C')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')

compiler/tests/org/jetbrains/kotlin/parsing/JetParsingTestGenerated.java

@@ -370,6 +370,12 @@ public class JetParsingTestGenerated extends AbstractJetParsingTest {
             doParsingTest(fileName);
         }
 
+        @TestMetadata("NamedClassObject.kt")
+        public void testNamedClassObject() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/psi/NamedClassObject.kt");
+            doParsingTest(fileName);
+        }
+
         @TestMetadata("NestedComments.kt")
         public void testNestedComments() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/psi/NestedComments.kt");