New J2K: Render list of implemented correctly

j2k/newSrc/org/jetbrains/kotlin/j2k/NewCodeBuilder.kt

@@ -96,6 +96,20 @@ class NewCodeBuilder {
             )
         }
 
+        override fun visitInheritanceInfo(inheritanceInfo: JKInheritanceInfo) {
+            renderList(inheritanceInfo.inherit) { it.accept(this) }
+        }
+
+
+        private inline fun <T> renderList(list: List<T>, separator: String = ", ", renderElement: (T) -> Unit) {
+            val (head, tail) = list.headTail()
+            head?.let(renderElement) ?: return
+            tail?.forEach {
+                builder.append(separator)
+                renderElement(it)
+            }
+        }
+
         override fun visitClass(klass: JKClass) {
             klass.modifierList.accept(this)
             builder.append(" ")
@@ -104,7 +118,7 @@ class NewCodeBuilder {
             printer.printWithNoIndent(klass.name.value)
             if (klass.inheritance.inherit.isNotEmpty()) {
                 printer.printWithNoIndent(" : ")
-                klass.inheritance.inherit.forEach { it.accept(this) }
+                klass.inheritance.accept(this)
             }
 
             if (klass.declarationList.isNotEmpty()) {
@@ -377,4 +391,10 @@ class NewCodeBuilder {
         Visitor().also { root.accept(it) }
         return builder.toString()
     }
+}
+
+private inline fun <T> List<T>.headTail(): Pair<T?, List<T>?> {
+    val head = this.firstOrNull()
+    val tail = if (size <= 1) null else subList(1, size)
+    return head to tail
 }

j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/jk.kt

@@ -325,4 +325,6 @@ class JKLambdaExpressionImpl(parameters: List<JKParameter>, returnType: JKTypeEl
 
 class JKInheritanceInfoImpl(implements: List<JKTypeElement>) : JKInheritanceInfo, JKBranchElementBase() {
     override val inherit: List<JKTypeElement> by children(implements)
+
+    override fun <R, D> accept(visitor: JKVisitor<R, D>, data: D): R = visitor.visitInheritanceInfo(this, data)
 }

j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitor.kt

@@ -7,6 +7,7 @@ interface JKVisitor<out R, in D> {
     fun visitDeclaration(declaration: JKDeclaration, data: D): R = visitTreeElement(declaration, data)
     fun visitFile(file: JKFile, data: D): R = visitTreeElement(file, data)
     fun visitClass(klass: JKClass, data: D): R = visitDeclaration(klass, data)
+    fun visitInheritanceInfo(inheritanceInfo: JKInheritanceInfo, data: D): R = visitTreeElement(inheritanceInfo, data)
     fun visitMethod(method: JKMethod, data: D): R = visitDeclaration(method, data)
     fun visitField(field: JKField, data: D): R = visitDeclaration(field, data)
     fun visitLocalVariable(localVariable: JKLocalVariable, data: D): R = visitField(localVariable, data)

j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitorVoid.kt

@@ -11,6 +11,8 @@ interface JKVisitorVoid : JKVisitor<Unit, Nothing?> {
     override fun visitFile(file: JKFile, data: Nothing?) = visitFile(file)
     fun visitClass(klass: JKClass) = visitDeclaration(klass, null)
     override fun visitClass(klass: JKClass, data: Nothing?) = visitClass(klass)
+    fun visitInheritanceInfo(inheritanceInfo: JKInheritanceInfo) = visitTreeElement(inheritanceInfo, null)
+    override fun visitInheritanceInfo(inheritanceInfo: JKInheritanceInfo, data: Nothing?) = visitInheritanceInfo(inheritanceInfo)
     fun visitMethod(method: JKMethod) = visitDeclaration(method, null)
     override fun visitMethod(method: JKMethod, data: Nothing?) = visitMethod(method)
     fun visitField(field: JKField) = visitDeclaration(field, null)