Add samples for Iterables #KT-20357

libraries/stdlib/samples/test/samples/collections/iterables.kt

@@ -0,0 +1,43 @@
+/*
+ * 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 samples.collections
+
+import samples.*
+import kotlin.coroutines.experimental.buildIterator
+import kotlin.test.*
+
+class Iterables {
+
+    @Sample
+    fun iterable() {
+        val iterable = Iterable { buildIterator { yieldAll(1..3) } }
+        val result = iterable.mapIndexed { index, i -> index + i }
+        assertPrints(result, "[1, 3, 5]")
+    }
+
+    @Sample
+    fun flattenIterable() {
+        val deepList = listOf(listOf(1), listOf(2, 3), listOf(4, 5, 6))
+        assertPrints(deepList.flatten(), "[1, 2, 3, 4, 5, 6]")
+    }
+
+    @Sample
+    fun unzipIterable() {
+        val list = listOf(1 to 'a', 2 to 'b', 3 to 'c')
+        assertPrints(list.unzip(), "([1, 2, 3], [a, b, c])")
+    }
+}