Move Appendable to its own file

libraries/stdlib/common/src/kotlin/TextH.kt

@@ -5,12 +5,6 @@
 
 package kotlin.text
 
-expect interface Appendable {
-    fun append(c: Char): Appendable
-    fun append(csq: CharSequence?): Appendable
-    fun append(csq: CharSequence?, start: Int, end: Int): Appendable
-}
-
 expect class StringBuilder : Appendable, CharSequence {
     constructor()
     constructor(capacity: Int)

libraries/stdlib/js/src/kotlin/text/AppendableJs.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.text
+
+/**
+ * An object to which char sequences and values can be appended.
+ */
+public actual interface Appendable {
+    /**
+     * Appends the specified character [c] to this Appendable and returns this instance.
+     *
+     * @param c the character to append.
+     */
+    public actual fun append(c: Char): Appendable
+
+    /**
+     * Appends the specified character sequence [csq] to this Appendable and returns this instance.
+     *
+     * @param csq the character sequence to append. If [csq] is `null`, then the four characters `"null"` are appended to this Appendable.
+     */
+    public actual fun append(csq: CharSequence?): Appendable
+
+    /**
+     * Appends a subsequence of the specified character sequence [csq] to this Appendable and returns this instance.
+     *
+     * @param csq the character sequence from which a subsequence is appended. If [csq] is `null`,
+     *  then characters are appended as if [csq] contained the four characters `"null"`.
+     * @param start the beginning (inclusive) of the subsequence to append.
+     * @param end the end (exclusive) of the subsequence to append.
+     *
+     * @throws IndexOutOfBoundsException or [IllegalArgumentException] when [start] or [end] is out of range of the [csq] character sequence indices or when `start > end`.
+     */
+    public actual fun append(csq: CharSequence?, start: Int, end: Int): Appendable
+}

libraries/stdlib/js/src/kotlin/text/StringBuilderJs.kt

@@ -5,13 +5,6 @@
 
 package kotlin.text
 
-
-public actual interface Appendable {
-    public actual fun append(csq: CharSequence?): Appendable
-    public actual fun append(csq: CharSequence?, start: Int, end: Int): Appendable
-    public actual fun append(c: Char): Appendable
-}
-
 public actual class StringBuilder(content: String = "") : Appendable, CharSequence {
     actual constructor(capacity: Int) : this() {}
 

libraries/stdlib/src/kotlin/text/Appendable.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+@file:kotlin.jvm.JvmMultifileClass
+@file:kotlin.jvm.JvmName("StringsKt")
+
+package kotlin.text
+
+/**
+ * An object to which char sequences and values can be appended.
+ */
+expect interface Appendable {
+    /**
+     * Appends the specified character [c] to this Appendable and returns this instance.
+     *
+     * @param c the character to append.
+     */
+    fun append(c: Char): Appendable
+
+    /**
+     * Appends the specified character sequence [csq] to this Appendable and returns this instance.
+     *
+     * @param csq the character sequence to append. If [csq] is `null`, then the four characters `"null"` are appended to this Appendable.
+     */
+    fun append(csq: CharSequence?): Appendable
+
+    /**
+     * Appends a subsequence of the specified character sequence [csq] to this Appendable and returns this instance.
+     *
+     * @param csq the character sequence from which a subsequence is appended. If [csq] is `null`,
+     *  then characters are appended as if [csq] contained the four characters `"null"`.
+     * @param start the beginning (inclusive) of the subsequence to append.
+     * @param end the end (exclusive) of the subsequence to append.
+     *
+     * @throws IndexOutOfBoundsException or [IllegalArgumentException] when [start] or [end] is out of range of the [csq] character sequence indices or when `start > end`.
+     */
+    fun append(csq: CharSequence?, start: Int, end: Int): Appendable
+}
+
+/**
+ * Appends all arguments to the given [Appendable].
+ */
+public fun <T : Appendable> T.append(vararg value: CharSequence?): T {
+    for (item in value)
+        append(item)
+    return this
+}
+
+
+internal fun <T> Appendable.appendElement(element: T, transform: ((T) -> CharSequence)?) {
+    when {
+        transform != null -> append(transform(element))
+        element is CharSequence? -> append(element)
+        element is Char -> append(element)
+        else -> append(element.toString())
+    }
+}

libraries/stdlib/src/kotlin/text/StringBuilder.kt

@@ -25,15 +25,6 @@ public inline fun buildString(builderAction: StringBuilder.() -> Unit): String =
 public inline fun buildString(capacity: Int, builderAction: StringBuilder.() -> Unit): String =
     StringBuilder(capacity).apply(builderAction).toString()
 
-/**
- * Appends all arguments to the given [Appendable].
- */
-public fun <T : Appendable> T.append(vararg value: CharSequence?): T {
-    for (item in value)
-        append(item)
-    return this
-}
-
 /**
  * Appends all arguments to the given StringBuilder.
  */
@@ -51,13 +42,3 @@ public fun StringBuilder.append(vararg value: Any?): StringBuilder {
         append(item)
     return this
 }
-
-
-internal fun <T> Appendable.appendElement(element: T, transform: ((T) -> CharSequence)?) {
-    when {
-        transform != null -> append(transform(element))
-        element is CharSequence? -> append(element)
-        element is Char -> append(element)
-        else -> append(element.toString())
-    }
-}