stdlib: Add clear and remove methods in AbstractMutableCollection

backend.native/tests/build.gradle

@@ -790,9 +790,9 @@ task lateinit_notInitialized(type: RunKonanTest) {
     source = "codegen/lateinit/notInitialized.kt"
 }
 
-task AbstractMutableCollectionRemoveAll(type: RunKonanTest) {
+task AbstractMutableCollection(type: RunKonanTest) {
     expectedExitStatus = 0
-    source = "runtime/collections/AbstractMutableCollectionRemoveAll.kt"
+    source = "runtime/collections/AbstractMutableCollection.kt"
 }
 
 task array0(type: RunKonanTest) {

backend.native/tests/external/stdlib/collections/CollectionTest/sortByInPlace.kt

@@ -8,7 +8,7 @@ inline fun <T, R : Comparable<R>> assertSorted(list: List<out T>, message: Strin
     }
     val it = list.iterator()
     var prev = selector(it.next())
-    while(it.hasNext()) {
+    while (it.hasNext()) {
         val cur = selector(it.next())
         assertTrue(prev.compareTo(cur) <= 0, message)
         prev = cur
@@ -21,7 +21,7 @@ inline fun <T, R : Comparable<R>> assertSortedDescending(list: List<out T>, mess
     }
     val it = list.iterator()
     var prev = selector(it.next())
-    while(it.hasNext()) {
+    while (it.hasNext()) {
         val cur = selector(it.next())
         assertTrue(prev.compareTo(cur) >= 0, message)
         prev = cur

backend.native/tests/runtime/collections/AbstractMutableCollection.kt

@@ -15,17 +15,6 @@ class TestCollection(): AbstractMutableCollection<Int>() {
         return true
     }
 
-    override fun remove(element: Int): Boolean {
-        val it = iterator()
-        while(it.hasNext()) {
-            if (it.next() == element) {
-                it.remove()
-                return true
-            }
-        }
-        return false
-    }
-
     override fun iterator(): MutableIterator<Int> = object: MutableIterator<Int> {
         var nextIndex = 0
 
@@ -67,4 +56,8 @@ fun main(args: Array<String>) {
     assertEquals(c, listOf(3, 4, 5, 4))
     c.retainAll(listOf(4, 5))
     assertEquals(c, listOf(4, 5, 4))
+    c.remove(4)
+    assertEquals(c, listOf(5, 4))
+    c.clear()
+    assertEquals(c, listOf())
 }

runtime/src/main/kotlin/kotlin/collections/AbstractCollection.kt

@@ -61,40 +61,50 @@ public abstract class AbstractMutableCollection<E> protected constructor(): Muta
     override public fun addAll(elements: Collection<E>): Boolean {
         var changed = false
         for (v in elements) {
-            if(add(v)) changed = true
+            if (add(v)) changed = true
         }
         return changed
     }
 
+    /**
+     * Removes a single instance of the specified element from this
+     * collection, if it is present.
+     *
+     * @return `true` if the element has been successfully removed; `false` if it was not present in the collection.
+     */
+    override fun remove(element: E): Boolean {
+        val it = iterator()
+        while (it.hasNext()) {
+            if (it.next() == element) {
+                it.remove()
+                return true
+            }
+        }
+        return false
+    }
+
     /**
      * Removes all of this collection's elements that are also contained in the specified collection.
      *
      * @return `true` if any of the specified elements was removed from the collection, `false` if the collection was not modified.
      */
-    override public fun removeAll(elements: Collection<E>): Boolean = removeAll(elements, true)
+    override public fun removeAll(elements: Collection<E>): Boolean = (this as MutableIterable<E>).removeAll { it in elements }
 
     /**
      * Retains only the elements in this collection that are contained in the specified collection.
      *
      * @return `true` if any element was removed from the collection, `false` if the collection was not modified.
      */
-    override public fun retainAll(elements: Collection<E>): Boolean = removeAll(elements, false)
+    override public fun retainAll(elements: Collection<E>): Boolean = (this as MutableIterable<E>).retainAll { it in elements }
 
     /**
-     * Removes the elements in this collection that are contained (if [contained] == true) or
+     * Removes all elements from this collection.
-     * not contained (if [contained] == false) in [elements].
-     *
-     * @return `true` if the collection has been modified and `false` otherwise.
      */
-    protected fun removeAll(elements: Collection<E>, contained: Boolean): Boolean {
+    override fun clear(): Unit {
         val it = iterator()
-        var changed = false
         while (it.hasNext()) {
-            if (elements.contains(it.next()) == contained) {
+            it.next()
-                it.remove()
+            it.remove()
-                changed = true
-            }
         }
-        return changed
     }
 }