diff --git a/j2k/GenerateJKTreeVisitor.kts b/j2k/GenerateJKTreeVisitorAndTransformer.kts
similarity index 53%
rename from j2k/GenerateJKTreeVisitor.kts
rename to j2k/GenerateJKTreeVisitorAndTransformer.kts
index be4740d648e..8cb6b0d2512 100644
--- a/j2k/GenerateJKTreeVisitor.kts
+++ b/j2k/GenerateJKTreeVisitorAndTransformer.kts
@@ -35,6 +35,8 @@ import java.io.File
 
 val JK_ROOT = File("./j2k/newSrc/org/jetbrains/kotlin/j2k/tree")
 
+val JK_OUT_ROOT = File(JK_ROOT, "visitors")
+
 val JK_KT_FILE = File(JK_ROOT, "k.kt")
 val JK_JAVA_FILE = File(JK_ROOT, "j.kt")
 val JK_COMMON_FILE = File(JK_ROOT, "jk.kt")
@@ -58,15 +60,17 @@ fun String.safeVarName() = when (this) {
     else -> this
 }
 
-fun genVisitors(interfaceData: List<InterfaceData>, visitorName: String, extends: String = "") {
+fun genVisitors(interfaceData: List<InterfaceData>, visitorName: String, transformerName: String, visitorExtends: String? = null, transformerExtends: String? = null) {
 
-    val outFile = File(JK_ROOT, "$visitorName.kt")
+    val pkg = "package org.jetbrains.kotlin.j2k.tree.visitors"
 
-    outFile.writeText(buildString {
-        appendln("package org.jetbrains.kotlin.j2k.tree")
+    File(JK_OUT_ROOT, "$visitorName.kt").writeText(buildString {
+        appendln(pkg)
         appendln()
-        val extends = if (extends.isNotBlank()) ": $extends<R, D>" else ""
-        appendln("interface $visitorName<R, D> $extends {")
+        appendln("import org.jetbrains.kotlin.j2k.tree.*")
+        appendln()
+        val extends = visitorExtends?.let { " : $it<R, D>" } ?: ""
+        appendln("interface $visitorName<R, D>$extends {")
         interfaceData.joinTo(this, separator = "\n") { (name, ext) ->
             val nameWithoutPrefix = name.removePrefix("JK")
             val argName = nameWithoutPrefix.decapitalize().safeVarName()
@@ -79,12 +83,13 @@ fun genVisitors(interfaceData: List<InterfaceData>, visitorName: String, extends
         appendln("}")
     })
 
-    val outVoidFile = File(JK_ROOT, "${visitorName}Void.kt")
 
-    outVoidFile.writeText(buildString {
-        appendln("package org.jetbrains.kotlin.j2k.tree")
+    File(JK_OUT_ROOT, "${visitorName}Void.kt").writeText(buildString {
+        appendln(pkg)
         appendln()
-        val extends = if (extends.isNotBlank()) ", ${extends}Void" else ""
+        appendln("import org.jetbrains.kotlin.j2k.tree.*")
+        appendln()
+        val extends = visitorExtends?.let { ", ${it}Void" } ?: ""
 
         appendln("interface ${visitorName}Void : $visitorName<Unit, Nothing?>$extends {")
         interfaceData.joinTo(this, separator = "\n") { (name, ext) ->
@@ -100,17 +105,54 @@ fun genVisitors(interfaceData: List<InterfaceData>, visitorName: String, extends
         appendln()
         appendln("}")
     })
+
+    File(JK_OUT_ROOT, "$transformerName.kt").writeText(buildString {
+        appendln(pkg)
+        appendln()
+        appendln("import org.jetbrains.kotlin.j2k.tree.*")
+        appendln()
+        val extends = transformerExtends?.let { " : $it<D>" } ?: ""
+
+        appendln("interface $transformerName<D>$extends {")
+
+        interfaceData.joinTo(this, separator = "\n") { (name, ext) ->
+            val nameWithoutPrefix = name.removePrefix("JK")
+            val argName = nameWithoutPrefix.decapitalize().safeVarName()
+            val generifyCall = if (name != "JKElement") "= transform${ext!!.removePrefix("JK")}($argName, data)" else ""
+            """
+            |    fun transform$nameWithoutPrefix($argName: $name, data: D): JKElement $generifyCall
+            """.trimMargin()
+        }
+        appendln()
+        appendln("}")
+    })
+
+
+    File(JK_OUT_ROOT, "${transformerName}Void.kt").writeText(buildString {
+        appendln(pkg)
+        appendln()
+        appendln("import org.jetbrains.kotlin.j2k.tree.*")
+        appendln()
+        val extends = transformerExtends?.let { ", ${it}Void" } ?: ""
+
+        appendln("interface ${transformerName}Void : $transformerName<Nothing?>$extends {")
+        interfaceData.joinTo(this, separator = "\n") { (name, ext) ->
+            val nameWithoutPrefix = name.removePrefix("JK")
+            val argName = nameWithoutPrefix.decapitalize().safeVarName()
+            val arg = "$argName: $name"
+            val generifyCall = if (name != "JKElement") "= transform${ext!!.removePrefix("JK")}($argName, null)" else ": JKElement"
+            """
+            |    fun transform$nameWithoutPrefix($arg) $generifyCall
+            |    override fun transform$nameWithoutPrefix($arg, data: Nothing?) = transform$nameWithoutPrefix($argName)
+            """.trimMargin()
+        }
+        appendln()
+        appendln("}")
+    })
 }
 
-// JKVisitor<R,D> + Void
-genVisitors(JK_COMMON_FILE.interfaceNames(), "JKVisitor")
-genVisitors(JK_JAVA_FILE.interfaceNames(), "JKJavaVisitor", "JKVisitor")
-genVisitors(JK_KT_FILE.interfaceNames(), "JKKtVisitor", "JKVisitor")
-
-/*   JKKtVisitor<R,D> : JKVisitor<R,D> + Void
-    JKJavaVisitor<R,D> : JKVisitor<R,D> + Void
- */
-
-//val visitNames =
+genVisitors(JK_COMMON_FILE.interfaceNames(), "JKVisitor", "JKTransformer")
+genVisitors(JK_JAVA_FILE.interfaceNames(), "JKJavaVisitor", "JKJavaTransformer", "JKVisitor", "JKTransformer")
+genVisitors(JK_KT_FILE.interfaceNames(), "JKKtVisitor", "JKKtTransformer", "JKVisitor", "JKTransformer")
 
 
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/DebugTreePrinter.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/DebugTreePrinter.kt
index 06b4e829c16..f0826e84cf8 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/DebugTreePrinter.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/DebugTreePrinter.kt
@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.j2k.tree
 
+import org.jetbrains.kotlin.j2k.tree.visitors.JKJavaKtVisitorVoid
 import org.jetbrains.kotlin.utils.Printer
 
 private class DebugTreePrinter : JKJavaKtVisitorVoid {
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaKtVisitorVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaKtVisitorVoid.kt
deleted file mode 100644
index 50fb4f562e6..00000000000
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaKtVisitorVoid.kt
+++ /dev/null
@@ -1,3 +0,0 @@
-package org.jetbrains.kotlin.j2k.tree
-
-interface JKJavaKtVisitorVoid : JKJavaKtVisitor<Unit, Nothing?>, JKJavaVisitorVoid, JKKtVisitorVoid
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/j.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/j.kt
index 1f4b096eb39..ea660979ba0 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/j.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/j.kt
@@ -17,6 +17,8 @@
 package org.jetbrains.kotlin.j2k.tree.impl
 
 import org.jetbrains.kotlin.j2k.tree.*
+import org.jetbrains.kotlin.j2k.tree.visitors.JKJavaVisitor
+import org.jetbrains.kotlin.j2k.tree.visitors.JKVisitor
 
 class JKJavaFieldImpl(override var type: JKTypeIdentifier,
                       override var name: JKNameIdentifier,
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/jk.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/jk.kt
index f872675085a..ba545059295 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/jk.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/impl/jk.kt
@@ -17,11 +17,17 @@
 package org.jetbrains.kotlin.j2k.tree.impl
 
 import org.jetbrains.kotlin.j2k.tree.*
+import org.jetbrains.kotlin.j2k.tree.visitors.JKTransformer
+import org.jetbrains.kotlin.j2k.tree.visitors.JKVisitor
 
 abstract class JKElementBase : JKElement {
     override fun <R, D> accept(visitor: JKVisitor<R, D>, data: D): R = visitor.visitElement(this, data)
 
     override fun <D> acceptChildren(visitor: JKVisitor<Unit, D>, data: D) {}
+
+    override fun <D> transform(transformer: JKTransformer<D>, data: D): JKElement = transformer.transformElement(this, data)
+
+    override fun <D> transformChildren(transformer: JKTransformer<D>, data: D) {}
 }
 
 
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/jk.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/jk.kt
index b5b3842672b..09d86e7b425 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/jk.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/jk.kt
@@ -16,11 +16,18 @@
 
 package org.jetbrains.kotlin.j2k.tree
 
+import org.jetbrains.kotlin.j2k.tree.visitors.JKTransformer
+import org.jetbrains.kotlin.j2k.tree.visitors.JKVisitor
+
 
 interface JKElement {
     fun <R, D> accept(visitor: JKVisitor<R, D>, data: D): R
 
     fun <D> acceptChildren(visitor: JKVisitor<Unit, D>, data: D)
+
+    fun <D> transform(transformer: JKTransformer<D>, data: D): JKElement
+
+    fun <D> transformChildren(transformer: JKTransformer<D>, data: D)
 }
 
 interface JKClass : JKDeclaration {
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtTransformer.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtTransformer.kt
new file mode 100644
index 00000000000..4f0e5b9147d
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtTransformer.kt
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+interface JKJavaKtTransformer<D> : JKJavaTransformer<D>, JKKtTransformer<D>
\ No newline at end of file
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtTransformerVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtTransformerVoid.kt
new file mode 100644
index 00000000000..a5a759d881a
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtTransformerVoid.kt
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+interface JKJavaKtTransformerVoid : JKJavaKtTransformer<Nothing?>, JKJavaTransformerVoid, JKKtTransformerVoid
\ No newline at end of file
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaKtVisitor.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtVisitor.kt
similarity index 61%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaKtVisitor.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtVisitor.kt
index 952b33e26d3..9b806e505e1 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaKtVisitor.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtVisitor.kt
@@ -1,3 +1,3 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
 
 interface JKJavaKtVisitor<R, D> : JKJavaVisitor<R, D>, JKKtVisitor<R, D>
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtVisitorVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtVisitorVoid.kt
new file mode 100644
index 00000000000..066a98bdeb3
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaKtVisitorVoid.kt
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+interface JKJavaKtVisitorVoid : JKJavaKtVisitor<Unit, Nothing?>, JKJavaVisitorVoid, JKKtVisitorVoid
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaTransformer.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaTransformer.kt
new file mode 100644
index 00000000000..ea42473c0db
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaTransformer.kt
@@ -0,0 +1,14 @@
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKJavaTransformer<D> : JKTransformer<D> {
+    fun transformJavaField(javaField: JKJavaField, data: D): JKElement = transformDeclaration(javaField, data)
+    fun transformJavaMethod(javaMethod: JKJavaMethod, data: D): JKElement = transformDeclaration(javaMethod, data)
+    fun transformJavaForLoop(javaForLoop: JKJavaForLoop, data: D): JKElement = transformLoop(javaForLoop, data)
+    fun transformJavaAssignmentExpression(javaAssignmentExpression: JKJavaAssignmentExpression, data: D): JKElement = transformExpression(javaAssignmentExpression, data)
+    fun transformJavaCall(javaCall: JKJavaCall, data: D): JKElement = transformCall(javaCall, data)
+    fun transformJavaTypeIdentifier(javaTypeIdentifier: JKJavaTypeIdentifier, data: D): JKElement = transformTypeIdentifier(javaTypeIdentifier, data)
+    fun transformJavaStringLiteralExpression(javaStringLiteralExpression: JKJavaStringLiteralExpression, data: D): JKElement = transformLiteralExpression(javaStringLiteralExpression, data)
+    fun transformJavaAccessModifier(javaAccessModifier: JKJavaAccessModifier, data: D): JKElement = transformAccessModifier(javaAccessModifier, data)
+}
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaTransformerVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaTransformerVoid.kt
new file mode 100644
index 00000000000..b6e59b49b74
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaTransformerVoid.kt
@@ -0,0 +1,22 @@
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKJavaTransformerVoid : JKJavaTransformer<Nothing?>, JKTransformerVoid {
+    fun transformJavaField(javaField: JKJavaField) = transformDeclaration(javaField, null)
+    override fun transformJavaField(javaField: JKJavaField, data: Nothing?) = transformJavaField(javaField)
+    fun transformJavaMethod(javaMethod: JKJavaMethod) = transformDeclaration(javaMethod, null)
+    override fun transformJavaMethod(javaMethod: JKJavaMethod, data: Nothing?) = transformJavaMethod(javaMethod)
+    fun transformJavaForLoop(javaForLoop: JKJavaForLoop) = transformLoop(javaForLoop, null)
+    override fun transformJavaForLoop(javaForLoop: JKJavaForLoop, data: Nothing?) = transformJavaForLoop(javaForLoop)
+    fun transformJavaAssignmentExpression(javaAssignmentExpression: JKJavaAssignmentExpression) = transformExpression(javaAssignmentExpression, null)
+    override fun transformJavaAssignmentExpression(javaAssignmentExpression: JKJavaAssignmentExpression, data: Nothing?) = transformJavaAssignmentExpression(javaAssignmentExpression)
+    fun transformJavaCall(javaCall: JKJavaCall) = transformCall(javaCall, null)
+    override fun transformJavaCall(javaCall: JKJavaCall, data: Nothing?) = transformJavaCall(javaCall)
+    fun transformJavaTypeIdentifier(javaTypeIdentifier: JKJavaTypeIdentifier) = transformTypeIdentifier(javaTypeIdentifier, null)
+    override fun transformJavaTypeIdentifier(javaTypeIdentifier: JKJavaTypeIdentifier, data: Nothing?) = transformJavaTypeIdentifier(javaTypeIdentifier)
+    fun transformJavaStringLiteralExpression(javaStringLiteralExpression: JKJavaStringLiteralExpression) = transformLiteralExpression(javaStringLiteralExpression, null)
+    override fun transformJavaStringLiteralExpression(javaStringLiteralExpression: JKJavaStringLiteralExpression, data: Nothing?) = transformJavaStringLiteralExpression(javaStringLiteralExpression)
+    fun transformJavaAccessModifier(javaAccessModifier: JKJavaAccessModifier) = transformAccessModifier(javaAccessModifier, null)
+    override fun transformJavaAccessModifier(javaAccessModifier: JKJavaAccessModifier, data: Nothing?) = transformJavaAccessModifier(javaAccessModifier)
+}
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaVisitor.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaVisitor.kt
similarity index 92%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaVisitor.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaVisitor.kt
index 5a574445d95..1342ac4a3cf 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaVisitor.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaVisitor.kt
@@ -1,4 +1,6 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
 
 interface JKJavaVisitor<R, D> : JKVisitor<R, D> {
     fun visitJavaField(javaField: JKJavaField, data: D): R = visitDeclaration(javaField, data)
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaVisitorVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaVisitorVoid.kt
similarity index 95%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaVisitorVoid.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaVisitorVoid.kt
index 915e9673c8f..e865e8982b2 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKJavaVisitorVoid.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKJavaVisitorVoid.kt
@@ -1,4 +1,6 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
 
 interface JKJavaVisitorVoid : JKJavaVisitor<Unit, Nothing?>, JKVisitorVoid {
     fun visitJavaField(javaField: JKJavaField) = visitDeclaration(javaField, null)
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtTransformer.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtTransformer.kt
new file mode 100644
index 00000000000..b1dae407caa
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtTransformer.kt
@@ -0,0 +1,11 @@
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKKtTransformer<D> : JKTransformer<D> {
+    fun transformKtFun(ktFun: JKKtFun, data: D): JKElement = transformDeclaration(ktFun, data)
+    fun transformKtConstructor(ktConstructor: JKKtConstructor, data: D): JKElement = transformDeclaration(ktConstructor, data)
+    fun transformKtPrimaryConstructor(ktPrimaryConstructor: JKKtPrimaryConstructor, data: D): JKElement = transformKtConstructor(ktPrimaryConstructor, data)
+    fun transformKtAssignmentStatement(ktAssignmentStatement: JKKtAssignmentStatement, data: D): JKElement = transformStatement(ktAssignmentStatement, data)
+    fun transformKtCall(ktCall: JKKtCall, data: D): JKElement = transformCall(ktCall, data)
+}
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtTransformerVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtTransformerVoid.kt
new file mode 100644
index 00000000000..06e61d65785
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtTransformerVoid.kt
@@ -0,0 +1,16 @@
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKKtTransformerVoid : JKKtTransformer<Nothing?>, JKTransformerVoid {
+    fun transformKtFun(ktFun: JKKtFun) = transformDeclaration(ktFun, null)
+    override fun transformKtFun(ktFun: JKKtFun, data: Nothing?) = transformKtFun(ktFun)
+    fun transformKtConstructor(ktConstructor: JKKtConstructor) = transformDeclaration(ktConstructor, null)
+    override fun transformKtConstructor(ktConstructor: JKKtConstructor, data: Nothing?) = transformKtConstructor(ktConstructor)
+    fun transformKtPrimaryConstructor(ktPrimaryConstructor: JKKtPrimaryConstructor) = transformKtConstructor(ktPrimaryConstructor, null)
+    override fun transformKtPrimaryConstructor(ktPrimaryConstructor: JKKtPrimaryConstructor, data: Nothing?) = transformKtPrimaryConstructor(ktPrimaryConstructor)
+    fun transformKtAssignmentStatement(ktAssignmentStatement: JKKtAssignmentStatement) = transformStatement(ktAssignmentStatement, null)
+    override fun transformKtAssignmentStatement(ktAssignmentStatement: JKKtAssignmentStatement, data: Nothing?) = transformKtAssignmentStatement(ktAssignmentStatement)
+    fun transformKtCall(ktCall: JKKtCall) = transformCall(ktCall, null)
+    override fun transformKtCall(ktCall: JKKtCall, data: Nothing?) = transformKtCall(ktCall)
+}
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKKtVisitor.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtVisitor.kt
similarity index 87%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKKtVisitor.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtVisitor.kt
index 3af1744681e..eb6fead5284 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKKtVisitor.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtVisitor.kt
@@ -1,4 +1,6 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
 
 interface JKKtVisitor<R, D> : JKVisitor<R, D> {
     fun visitKtFun(ktFun: JKKtFun, data: D): R = visitDeclaration(ktFun, data)
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKKtVisitorVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtVisitorVoid.kt
similarity index 93%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKKtVisitorVoid.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtVisitorVoid.kt
index fc7af609b76..115f50c517c 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKKtVisitorVoid.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKKtVisitorVoid.kt
@@ -1,4 +1,6 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
 
 interface JKKtVisitorVoid : JKKtVisitor<Unit, Nothing?>, JKVisitorVoid {
     fun visitKtFun(ktFun: JKKtFun) = visitDeclaration(ktFun, null)
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKTransformer.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKTransformer.kt
new file mode 100644
index 00000000000..689133eac7a
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKTransformer.kt
@@ -0,0 +1,21 @@
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKTransformer<D> {
+    fun transformElement(element: JKElement, data: D): JKElement 
+    fun transformClass(klass: JKClass, data: D): JKElement = transformDeclaration(klass, data)
+    fun transformStatement(statement: JKStatement, data: D): JKElement = transformElement(statement, data)
+    fun transformExpression(expression: JKExpression, data: D): JKElement = transformStatement(expression, data)
+    fun transformLoop(loop: JKLoop, data: D): JKElement = transformStatement(loop, data)
+    fun transformDeclaration(declaration: JKDeclaration, data: D): JKElement = transformElement(declaration, data)
+    fun transformBlock(block: JKBlock, data: D): JKElement = transformElement(block, data)
+    fun transformCall(call: JKCall, data: D): JKElement = transformExpression(call, data)
+    fun transformIdentifier(identifier: JKIdentifier, data: D): JKElement = transformElement(identifier, data)
+    fun transformTypeIdentifier(typeIdentifier: JKTypeIdentifier, data: D): JKElement = transformIdentifier(typeIdentifier, data)
+    fun transformNameIdentifier(nameIdentifier: JKNameIdentifier, data: D): JKElement = transformIdentifier(nameIdentifier, data)
+    fun transformLiteralExpression(literalExpression: JKLiteralExpression, data: D): JKElement = transformExpression(literalExpression, data)
+    fun transformModifierList(modifierList: JKModifierList, data: D): JKElement = transformElement(modifierList, data)
+    fun transformModifier(modifier: JKModifier, data: D): JKElement = transformElement(modifier, data)
+    fun transformAccessModifier(accessModifier: JKAccessModifier, data: D): JKElement = transformModifier(accessModifier, data)
+}
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKTransformerVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKTransformerVoid.kt
new file mode 100644
index 00000000000..7c73369fbe1
--- /dev/null
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKTransformerVoid.kt
@@ -0,0 +1,36 @@
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKTransformerVoid : JKTransformer<Nothing?> {
+    fun transformElement(element: JKElement) : JKElement
+    override fun transformElement(element: JKElement, data: Nothing?) = transformElement(element)
+    fun transformClass(klass: JKClass) = transformDeclaration(klass, null)
+    override fun transformClass(klass: JKClass, data: Nothing?) = transformClass(klass)
+    fun transformStatement(statement: JKStatement) = transformElement(statement, null)
+    override fun transformStatement(statement: JKStatement, data: Nothing?) = transformStatement(statement)
+    fun transformExpression(expression: JKExpression) = transformStatement(expression, null)
+    override fun transformExpression(expression: JKExpression, data: Nothing?) = transformExpression(expression)
+    fun transformLoop(loop: JKLoop) = transformStatement(loop, null)
+    override fun transformLoop(loop: JKLoop, data: Nothing?) = transformLoop(loop)
+    fun transformDeclaration(declaration: JKDeclaration) = transformElement(declaration, null)
+    override fun transformDeclaration(declaration: JKDeclaration, data: Nothing?) = transformDeclaration(declaration)
+    fun transformBlock(block: JKBlock) = transformElement(block, null)
+    override fun transformBlock(block: JKBlock, data: Nothing?) = transformBlock(block)
+    fun transformCall(call: JKCall) = transformExpression(call, null)
+    override fun transformCall(call: JKCall, data: Nothing?) = transformCall(call)
+    fun transformIdentifier(identifier: JKIdentifier) = transformElement(identifier, null)
+    override fun transformIdentifier(identifier: JKIdentifier, data: Nothing?) = transformIdentifier(identifier)
+    fun transformTypeIdentifier(typeIdentifier: JKTypeIdentifier) = transformIdentifier(typeIdentifier, null)
+    override fun transformTypeIdentifier(typeIdentifier: JKTypeIdentifier, data: Nothing?) = transformTypeIdentifier(typeIdentifier)
+    fun transformNameIdentifier(nameIdentifier: JKNameIdentifier) = transformIdentifier(nameIdentifier, null)
+    override fun transformNameIdentifier(nameIdentifier: JKNameIdentifier, data: Nothing?) = transformNameIdentifier(nameIdentifier)
+    fun transformLiteralExpression(literalExpression: JKLiteralExpression) = transformExpression(literalExpression, null)
+    override fun transformLiteralExpression(literalExpression: JKLiteralExpression, data: Nothing?) = transformLiteralExpression(literalExpression)
+    fun transformModifierList(modifierList: JKModifierList) = transformElement(modifierList, null)
+    override fun transformModifierList(modifierList: JKModifierList, data: Nothing?) = transformModifierList(modifierList)
+    fun transformModifier(modifier: JKModifier) = transformElement(modifier, null)
+    override fun transformModifier(modifier: JKModifier, data: Nothing?) = transformModifier(modifier)
+    fun transformAccessModifier(accessModifier: JKAccessModifier) = transformModifier(accessModifier, null)
+    override fun transformAccessModifier(accessModifier: JKAccessModifier, data: Nothing?) = transformAccessModifier(accessModifier)
+}
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitor.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitor.kt
similarity index 92%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitor.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitor.kt
index ea51f23b256..92ded4830c8 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitor.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitor.kt
@@ -1,6 +1,8 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
 
-interface JKVisitor<R, D>  {
+import org.jetbrains.kotlin.j2k.tree.*
+
+interface JKVisitor<R, D> {
     fun visitElement(element: JKElement, data: D): R 
     fun visitClass(klass: JKClass, data: D): R = visitDeclaration(klass, data)
     fun visitStatement(statement: JKStatement, data: D): R = visitElement(statement, data)
diff --git a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitorVoid.kt b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitorVoid.kt
similarity index 97%
rename from j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitorVoid.kt
rename to j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitorVoid.kt
index b91c1f70110..aaf8be931dc 100644
--- a/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/JKVisitorVoid.kt
+++ b/j2k/newSrc/org/jetbrains/kotlin/j2k/tree/visitors/JKVisitorVoid.kt
@@ -1,4 +1,6 @@
-package org.jetbrains.kotlin.j2k.tree
+package org.jetbrains.kotlin.j2k.tree.visitors
+
+import org.jetbrains.kotlin.j2k.tree.*
 
 interface JKVisitorVoid : JKVisitor<Unit, Nothing?> {
     fun visitElement(element: JKElement)