From f6178ad7dd2cb02e2c3dfa828fdbfba85de5a70d Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Mon, 13 Apr 2015 18:26:38 +0300
Subject: [PATCH] Introduce Function, KFunction interfaces and 'extension'
 annotation

---
 compiler/testData/builtin-classes.txt         |  4 ++
 core/builtins/src/kotlin/Annotations.kt       |  5 ++
 .../builtins/src/kotlin/ExtensionFunctions.kt | 46 +++++++++----------
 core/builtins/src/kotlin/Function.kt          | 22 +++++++++
 core/builtins/src/kotlin/Functions.kt         | 46 +++++++++----------
 .../src/kotlin/reflect/KExtensionFunction.kt  | 27 +++++++++++
 core/builtins/src/kotlin/reflect/KFunction.kt | 22 +++++++++
 .../src/kotlin/reflect/KMemberFunction.kt     | 26 +++++++++++
 .../reflect/KTopLevelExtensionFunction.kt     | 25 ++++++++++
 .../src/kotlin/reflect/KTopLevelFunction.kt   | 22 +++++++++
 .../kotlin/generators/builtins/functions.kt   | 17 +++++--
 j2k/src/org/jetbrains/kotlin/j2k/Converter.kt |  1 +
 jslib_files.xml                               |  1 +
 13 files changed, 215 insertions(+), 49 deletions(-)
 create mode 100644 core/builtins/src/kotlin/Function.kt
 create mode 100644 core/builtins/src/kotlin/reflect/KExtensionFunction.kt
 create mode 100644 core/builtins/src/kotlin/reflect/KFunction.kt
 create mode 100644 core/builtins/src/kotlin/reflect/KMemberFunction.kt
 create mode 100644 core/builtins/src/kotlin/reflect/KTopLevelExtensionFunction.kt
 create mode 100644 core/builtins/src/kotlin/reflect/KTopLevelFunction.kt

diff --git a/compiler/testData/builtin-classes.txt b/compiler/testData/builtin-classes.txt
index de962a23b15..ed56381ec68 100644
--- a/compiler/testData/builtin-classes.txt
+++ b/compiler/testData/builtin-classes.txt
@@ -1522,6 +1522,10 @@ public final annotation class deprecated : kotlin.Annotation {
         internal final fun <get-value>(): kotlin.String
 }
 
+public final annotation class extension : kotlin.Annotation {
+    /*primary*/ public constructor extension()
+}
+
 public final annotation class inline : kotlin.Annotation {
     /*primary*/ public constructor inline(/*0*/ strategy: kotlin.InlineStrategy = ...)
     public final val strategy: kotlin.InlineStrategy
diff --git a/core/builtins/src/kotlin/Annotations.kt b/core/builtins/src/kotlin/Annotations.kt
index 4ae8756cd5a..4136eb529b9 100644
--- a/core/builtins/src/kotlin/Annotations.kt
+++ b/core/builtins/src/kotlin/Annotations.kt
@@ -30,6 +30,11 @@ public annotation class data
  */
 public annotation class deprecated(val value: String)
 
+/**
+ * Signifies that the annotated functional type represents an extension function.
+ */
+public annotation class extension
+
 /**
  * Suppresses the given compilation warnings in the annotated element.
  * @property names names of the compiler diagnostics to suppress.
diff --git a/core/builtins/src/kotlin/ExtensionFunctions.kt b/core/builtins/src/kotlin/ExtensionFunctions.kt
index 1b4f7edb90e..7621541f9e5 100644
--- a/core/builtins/src/kotlin/ExtensionFunctions.kt
+++ b/core/builtins/src/kotlin/ExtensionFunctions.kt
@@ -19,117 +19,117 @@
 package kotlin
 
 /** An extension function that takes 0 arguments. */
-public interface ExtensionFunction0<in T, out R> {
+public interface ExtensionFunction0<in T, out R> : Function<R> {
     /** Invokes the function. */
     public fun T.invoke(): R
 }
 /** An extension function that takes 1 argument. */
-public interface ExtensionFunction1<in T, in P1, out R> {
+public interface ExtensionFunction1<in T, in P1, out R> : Function<R> {
     /** Invokes the function with the specified argument. */
     public fun T.invoke(p1: P1): R
 }
 /** An extension function that takes 2 arguments. */
-public interface ExtensionFunction2<in T, in P1, in P2, out R> {
+public interface ExtensionFunction2<in T, in P1, in P2, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2): R
 }
 /** An extension function that takes 3 arguments. */
-public interface ExtensionFunction3<in T, in P1, in P2, in P3, out R> {
+public interface ExtensionFunction3<in T, in P1, in P2, in P3, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3): R
 }
 /** An extension function that takes 4 arguments. */
-public interface ExtensionFunction4<in T, in P1, in P2, in P3, in P4, out R> {
+public interface ExtensionFunction4<in T, in P1, in P2, in P3, in P4, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4): R
 }
 /** An extension function that takes 5 arguments. */
-public interface ExtensionFunction5<in T, in P1, in P2, in P3, in P4, in P5, out R> {
+public interface ExtensionFunction5<in T, in P1, in P2, in P3, in P4, in P5, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5): R
 }
 /** An extension function that takes 6 arguments. */
-public interface ExtensionFunction6<in T, in P1, in P2, in P3, in P4, in P5, in P6, out R> {
+public interface ExtensionFunction6<in T, in P1, in P2, in P3, in P4, in P5, in P6, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6): R
 }
 /** An extension function that takes 7 arguments. */
-public interface ExtensionFunction7<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, out R> {
+public interface ExtensionFunction7<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7): R
 }
 /** An extension function that takes 8 arguments. */
-public interface ExtensionFunction8<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, out R> {
+public interface ExtensionFunction8<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8): R
 }
 /** An extension function that takes 9 arguments. */
-public interface ExtensionFunction9<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, out R> {
+public interface ExtensionFunction9<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9): R
 }
 /** An extension function that takes 10 arguments. */
-public interface ExtensionFunction10<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, out R> {
+public interface ExtensionFunction10<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10): R
 }
 /** An extension function that takes 11 arguments. */
-public interface ExtensionFunction11<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, out R> {
+public interface ExtensionFunction11<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11): R
 }
 /** An extension function that takes 12 arguments. */
-public interface ExtensionFunction12<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, out R> {
+public interface ExtensionFunction12<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12): R
 }
 /** An extension function that takes 13 arguments. */
-public interface ExtensionFunction13<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, out R> {
+public interface ExtensionFunction13<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13): R
 }
 /** An extension function that takes 14 arguments. */
-public interface ExtensionFunction14<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, out R> {
+public interface ExtensionFunction14<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14): R
 }
 /** An extension function that takes 15 arguments. */
-public interface ExtensionFunction15<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, out R> {
+public interface ExtensionFunction15<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15): R
 }
 /** An extension function that takes 16 arguments. */
-public interface ExtensionFunction16<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, out R> {
+public interface ExtensionFunction16<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16): R
 }
 /** An extension function that takes 17 arguments. */
-public interface ExtensionFunction17<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, out R> {
+public interface ExtensionFunction17<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17): R
 }
 /** An extension function that takes 18 arguments. */
-public interface ExtensionFunction18<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, out R> {
+public interface ExtensionFunction18<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18): R
 }
 /** An extension function that takes 19 arguments. */
-public interface ExtensionFunction19<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, out R> {
+public interface ExtensionFunction19<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19): R
 }
 /** An extension function that takes 20 arguments. */
-public interface ExtensionFunction20<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, out R> {
+public interface ExtensionFunction20<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19, p20: P20): R
 }
 /** An extension function that takes 21 arguments. */
-public interface ExtensionFunction21<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, out R> {
+public interface ExtensionFunction21<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19, p20: P20, p21: P21): R
 }
 /** An extension function that takes 22 arguments. */
-public interface ExtensionFunction22<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, in P22, out R> {
+public interface ExtensionFunction22<in T, in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, in P22, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun T.invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19, p20: P20, p21: P21, p22: P22): R
 }
diff --git a/core/builtins/src/kotlin/Function.kt b/core/builtins/src/kotlin/Function.kt
new file mode 100644
index 00000000000..4002a56dabb
--- /dev/null
+++ b/core/builtins/src/kotlin/Function.kt
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2010-2015 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 kotlin
+
+/**
+ * Represents a value of a functional type, such as a lambda, a function expression or a function reference.
+ */
+public interface Function<out R>
diff --git a/core/builtins/src/kotlin/Functions.kt b/core/builtins/src/kotlin/Functions.kt
index 81ac8c558bc..5fbbf8e60ff 100644
--- a/core/builtins/src/kotlin/Functions.kt
+++ b/core/builtins/src/kotlin/Functions.kt
@@ -19,117 +19,117 @@
 package kotlin
 
 /** A function that takes 0 arguments. */
-public interface Function0<out R> {
+public interface Function0<out R> : Function<R> {
     /** Invokes the function. */
     public fun invoke(): R
 }
 /** A function that takes 1 argument. */
-public interface Function1<in P1, out R> {
+public interface Function1<in P1, out R> : Function<R> {
     /** Invokes the function with the specified argument. */
     public fun invoke(p1: P1): R
 }
 /** A function that takes 2 arguments. */
-public interface Function2<in P1, in P2, out R> {
+public interface Function2<in P1, in P2, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2): R
 }
 /** A function that takes 3 arguments. */
-public interface Function3<in P1, in P2, in P3, out R> {
+public interface Function3<in P1, in P2, in P3, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3): R
 }
 /** A function that takes 4 arguments. */
-public interface Function4<in P1, in P2, in P3, in P4, out R> {
+public interface Function4<in P1, in P2, in P3, in P4, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4): R
 }
 /** A function that takes 5 arguments. */
-public interface Function5<in P1, in P2, in P3, in P4, in P5, out R> {
+public interface Function5<in P1, in P2, in P3, in P4, in P5, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5): R
 }
 /** A function that takes 6 arguments. */
-public interface Function6<in P1, in P2, in P3, in P4, in P5, in P6, out R> {
+public interface Function6<in P1, in P2, in P3, in P4, in P5, in P6, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6): R
 }
 /** A function that takes 7 arguments. */
-public interface Function7<in P1, in P2, in P3, in P4, in P5, in P6, in P7, out R> {
+public interface Function7<in P1, in P2, in P3, in P4, in P5, in P6, in P7, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7): R
 }
 /** A function that takes 8 arguments. */
-public interface Function8<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, out R> {
+public interface Function8<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8): R
 }
 /** A function that takes 9 arguments. */
-public interface Function9<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, out R> {
+public interface Function9<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9): R
 }
 /** A function that takes 10 arguments. */
-public interface Function10<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, out R> {
+public interface Function10<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10): R
 }
 /** A function that takes 11 arguments. */
-public interface Function11<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, out R> {
+public interface Function11<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11): R
 }
 /** A function that takes 12 arguments. */
-public interface Function12<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, out R> {
+public interface Function12<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12): R
 }
 /** A function that takes 13 arguments. */
-public interface Function13<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, out R> {
+public interface Function13<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13): R
 }
 /** A function that takes 14 arguments. */
-public interface Function14<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, out R> {
+public interface Function14<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14): R
 }
 /** A function that takes 15 arguments. */
-public interface Function15<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, out R> {
+public interface Function15<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15): R
 }
 /** A function that takes 16 arguments. */
-public interface Function16<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, out R> {
+public interface Function16<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16): R
 }
 /** A function that takes 17 arguments. */
-public interface Function17<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, out R> {
+public interface Function17<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17): R
 }
 /** A function that takes 18 arguments. */
-public interface Function18<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, out R> {
+public interface Function18<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18): R
 }
 /** A function that takes 19 arguments. */
-public interface Function19<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, out R> {
+public interface Function19<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19): R
 }
 /** A function that takes 20 arguments. */
-public interface Function20<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, out R> {
+public interface Function20<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19, p20: P20): R
 }
 /** A function that takes 21 arguments. */
-public interface Function21<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, out R> {
+public interface Function21<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19, p20: P20, p21: P21): R
 }
 /** A function that takes 22 arguments. */
-public interface Function22<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, in P22, out R> {
+public interface Function22<in P1, in P2, in P3, in P4, in P5, in P6, in P7, in P8, in P9, in P10, in P11, in P12, in P13, in P14, in P15, in P16, in P17, in P18, in P19, in P20, in P21, in P22, out R> : Function<R> {
     /** Invokes the function with the specified arguments. */
     public fun invoke(p1: P1, p2: P2, p3: P3, p4: P4, p5: P5, p6: P6, p7: P7, p8: P8, p9: P9, p10: P10, p11: P11, p12: P12, p13: P13, p14: P14, p15: P15, p16: P16, p17: P17, p18: P18, p19: P19, p20: P20, p21: P21, p22: P22): R
 }
diff --git a/core/builtins/src/kotlin/reflect/KExtensionFunction.kt b/core/builtins/src/kotlin/reflect/KExtensionFunction.kt
new file mode 100644
index 00000000000..d2b861e14e7
--- /dev/null
+++ b/core/builtins/src/kotlin/reflect/KExtensionFunction.kt
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2010-2015 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 kotlin.reflect
+
+/**
+ * Represents an extension function.
+ * See the [Kotlin language documentation](http://kotlinlang.org/docs/reference/extensions.html#extension-functions)
+ * for more information.
+ *
+ * @param E the type of the extension receiver.
+ * @param R the return type of the function.
+ */
+public interface KExtensionFunction<in E, out R> : KFunction<R>
diff --git a/core/builtins/src/kotlin/reflect/KFunction.kt b/core/builtins/src/kotlin/reflect/KFunction.kt
new file mode 100644
index 00000000000..127496163cc
--- /dev/null
+++ b/core/builtins/src/kotlin/reflect/KFunction.kt
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2010-2015 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 kotlin.reflect
+
+/**
+ * Represents a function with introspection capabilities.
+ */
+public interface KFunction<out R> : Function<R>
diff --git a/core/builtins/src/kotlin/reflect/KMemberFunction.kt b/core/builtins/src/kotlin/reflect/KMemberFunction.kt
new file mode 100644
index 00000000000..70a1c36faef
--- /dev/null
+++ b/core/builtins/src/kotlin/reflect/KMemberFunction.kt
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2010-2015 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 kotlin.reflect
+
+/**
+ * Represents a member function.
+ *
+ * @param T the type of the instance which should be used to call the function.
+ *          Must be derived either from a class declaring this function, or any subclass of that class.
+ * @param R the return type of the function.
+ */
+public interface KMemberFunction<in T : Any, out R> : KFunction<R>
diff --git a/core/builtins/src/kotlin/reflect/KTopLevelExtensionFunction.kt b/core/builtins/src/kotlin/reflect/KTopLevelExtensionFunction.kt
new file mode 100644
index 00000000000..133b1bb61d8
--- /dev/null
+++ b/core/builtins/src/kotlin/reflect/KTopLevelExtensionFunction.kt
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2010-2015 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 kotlin.reflect
+
+/**
+ * Represents an extension function declared in a package.
+ *
+ * @param E the type of the extension receiver.
+ * @param R the return type of the function.
+ */
+public interface KTopLevelExtensionFunction<in E, out R> : KExtensionFunction<E, R>
diff --git a/core/builtins/src/kotlin/reflect/KTopLevelFunction.kt b/core/builtins/src/kotlin/reflect/KTopLevelFunction.kt
new file mode 100644
index 00000000000..2f0d18f09bf
--- /dev/null
+++ b/core/builtins/src/kotlin/reflect/KTopLevelFunction.kt
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2010-2015 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 kotlin.reflect
+
+/**
+ * Represents a function declared in a package.
+ */
+public interface KTopLevelFunction<out R> : KFunction<R>
diff --git a/generators/src/org/jetbrains/kotlin/generators/builtins/functions.kt b/generators/src/org/jetbrains/kotlin/generators/builtins/functions.kt
index 17f74502ddf..1b33a42da90 100644
--- a/generators/src/org/jetbrains/kotlin/generators/builtins/functions.kt
+++ b/generators/src/org/jetbrains/kotlin/generators/builtins/functions.kt
@@ -58,15 +58,21 @@ class GenerateFunctions(out: PrintWriter, val kind: FunctionKind) : BuiltInsSour
             out.print("P$j, ")
         }
 
+        generateReturnTypeParameter(variance)
+
+        out.print(">")
+    }
+
+    fun generateReturnTypeParameter(variance: Boolean) {
         if (variance) out.print("out ")
-        out.print("R>")
+        out.print("R")
     }
 
     override fun generateBody() {
         for (i in 0..MAX_PARAM_COUNT) {
             generateDocumentation(i)
             out.print("public interface " + kind.getClassName(i))
-            generateTypeParameters(i, true)
+            generateTypeParameters(i, variance = true)
             generateSuperClass(i)
             generateFunctionClassBody(i)
         }
@@ -81,7 +87,12 @@ class GenerateFunctions(out: PrintWriter, val kind: FunctionKind) : BuiltInsSour
         val superClass = kind.getSuperClassName(i)
         if (superClass != null) {
             out.print(" : $superClass")
-            generateTypeParameters(i, false)
+            generateTypeParameters(i, variance = false)
+        }
+        else {
+            out.print(" : Function<")
+            generateReturnTypeParameter(variance = false)
+            out.print(">")
         }
     }
 
diff --git a/j2k/src/org/jetbrains/kotlin/j2k/Converter.kt b/j2k/src/org/jetbrains/kotlin/j2k/Converter.kt
index 87ee72d3cf7..d8cb5ce16ff 100644
--- a/j2k/src/org/jetbrains/kotlin/j2k/Converter.kt
+++ b/j2k/src/org/jetbrains/kotlin/j2k/Converter.kt
@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.j2k.ast.*
 import org.jetbrains.kotlin.j2k.ast.Annotation
 import org.jetbrains.kotlin.j2k.ast.Class
 import org.jetbrains.kotlin.j2k.ast.Enum
+import org.jetbrains.kotlin.j2k.ast.Function
 import org.jetbrains.kotlin.j2k.ast.Object
 import org.jetbrains.kotlin.j2k.usageProcessing.FieldToPropertyProcessing
 import org.jetbrains.kotlin.j2k.usageProcessing.UsageProcessing
diff --git a/jslib_files.xml b/jslib_files.xml
index 6a05d54f78d..32baa630167 100644
--- a/jslib_files.xml
+++ b/jslib_files.xml
@@ -3,6 +3,7 @@
         <include name="native/kotlin/Iterator.kt"/>
         <include name="native/kotlin/Collections.kt"/>
         <include name="src/kotlin/ExtensionFunctions.kt"/>
+        <include name="src/kotlin/Function.kt"/>
         <include name="src/kotlin/Functions.kt"/>
         <include name="src/kotlin/Iterators.kt"/>
         <include name="src/kotlin/Range.kt"/>