StringBuilder builder and appendln

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

@@ -0,0 +1,37 @@
+package kotlin
+
+/**
+ * Builds newly created StringBuilder using provided body.
+ */
+public inline fun StringBuilder(body: StringBuilder.() -> Unit): StringBuilder {
+    val sb = StringBuilder()
+    sb.body()
+    return sb
+}
+
+/**
+ * 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
+ */
+public fun StringBuilder.append(vararg value: String?): StringBuilder {
+    for (item in value)
+        append(item)
+    return this
+}
+
+/**
+ * Appends all arguments to the given StringBuilder
+ */
+public fun StringBuilder.append(vararg value: Any?): StringBuilder {
+    for (item in value)
+        append(item)
+    return this
+}

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

@@ -0,0 +1,59 @@
+package kotlin
+
+/** Line separator for current system. */
+val LINE_SEPARATOR: String = System.getProperty("line.separator")!!
+
+/** Appends line separator to Appendable. */
+public fun Appendable.appendln(): Appendable = append(LINE_SEPARATOR)
+
+/** Appends value to the given Appendable and line separator after it. */
+public fun Appendable.appendln(value: CharSequence?): Appendable = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given Appendable and line separator after it. */
+public fun Appendable.appendln(value: Char): Appendable = append(value).append(LINE_SEPARATOR)
+
+/** Appends line separator to StringBuilder. */
+
+public fun StringBuilder.appendln(): StringBuilder = append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: StringBuffer?): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: CharSequence?): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: String?): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Any?): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: StringBuilder?): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: CharArray): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Char): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Boolean): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Int): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Short): StringBuilder = append(value.toInt()).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Byte): StringBuilder = append(value.toInt()).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Long): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Float): StringBuilder = append(value).append(LINE_SEPARATOR)
+
+/** Appends value to the given StringBuilder and line separator after it. */
+public fun StringBuilder.appendln(value: Double): StringBuilder = append(value).append(LINE_SEPARATOR)

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

@@ -57,11 +57,11 @@ public val String.indices: IntRange
  * Returns a subsequence specified by given set of indices.
  */
 public fun CharSequence.slice(indices: Iterable<Int>): CharSequence {
-    val result = StringBuilder()
+    val sb = StringBuilder()
     for (i in indices) {
-        result.append(get(i))
+        sb.append(get(i))
     }
-    return result.toString()
+    return sb.toString()
 }
 
 /**

libraries/stdlib/test/text/StringBuilderTest.kt

@@ -0,0 +1,28 @@
+package test.text
+
+import kotlin.test.*
+import org.junit.Test as test
+
+class StringBuilderTest {
+
+    test fun stringBuild() {
+        val s = StringBuilder {
+            append("a")
+            append(true)
+        }.toString()
+        assertEquals("atrue", s)
+    }
+
+    test fun appendMany() {
+        assertEquals("a1", StringBuilder().append("a", "1").toString())
+        assertEquals("a1", StringBuilder().append("a", 1).toString())
+        assertEquals("a1", StringBuilder().append("a", StringBuilder().append("1")).toString())
+    }
+
+    test fun append() {
+        // this test is needed for JS implementation
+        assertEquals("em", StringBuilder {
+            append("element", 2, 4)
+        }.toString())
+    }
+}

libraries/stdlib/test/text/StringTest.kt

@@ -123,5 +123,4 @@ class StringTest {
         assertEquals("new name", s.replaceBefore("=", "new name"))
         assertEquals("/new/path", s.replaceBeforeLast("=", "/new/path"))
     }
-
 }