Add isNullOrEmpty() to Array, Collection, and Map. Fixes KT-23279

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

@@ -32,6 +32,18 @@ class Arrays {
             val array: Array<Char>? = arrayOf('a', 'b', 'c')
             assertPrints(array.orEmpty().contentToString(), "[a, b, c]")
         }
+
+        @Sample
+        fun arrayIsNullOrEmpty() {
+            val nullArray: Array<Any>? = null
+            assertTrue(nullArray.isNullOrEmpty())
+
+            val emptyArray = emptyArray<Any>()
+            assertTrue(emptyArray.isNullOrEmpty())
+
+            val array = arrayOf('a', 'b', 'c')
+            assertFalse(array.isNullOrEmpty())
+        }
     }
 
     class Transformations {

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

@@ -53,13 +53,13 @@ class Collections {
 
         @Sample
         fun collectionIsNullOrEmpty() {
-            val nullCollection: Collection<Any>? = null
-            assertTrue(nullCollection.isNullOrEmpty())
+            val nullList: List<Any>? = null
+            assertTrue(nullList.isNullOrEmpty())
 
-            val emptyCollection: Collection<Any>? = listOf()
-            assertTrue(emptyCollection.isNullOrEmpty())
+            val empty: List<Any>? = emptyList<Any>()
+            assertTrue(empty.isNullOrEmpty())
 
-            val collection: Collection<Char>? = listOf('a', 'b', 'c')
+            val collection: List<Char>? = listOf('a', 'b', 'c')
             assertFalse(collection.isNullOrEmpty())
         }
 

libraries/stdlib/src/kotlin/collections/Arrays.kt

@@ -37,3 +37,9 @@ public fun <T, R> Array<out Pair<T, R>>.unzip(): Pair<List<T>, List<R>> {
     }
     return listT to listR
 }
+
+/**
+ * Returns `true` if this array is null or empty.
+ * @sample samples.collections.Arrays.Usage.arrayIsNullOrEmpty
+ */
+public fun Array<*>?.isNullOrEmpty(): Boolean = this == null || this.isEmpty()

libraries/stdlib/src/kotlin/collections/Maps.kt

@@ -140,6 +140,10 @@ private const val INT_MAX_POWER_OF_TWO: Int = Int.MAX_VALUE / 2 + 1
 @kotlin.internal.InlineOnly
 public inline fun <K, V> Map<out K, V>.isNotEmpty(): Boolean = !isEmpty()
 
+/** Returns `true` if this map is null or empty. */
+@kotlin.internal.InlineOnly
+public inline fun <K, V> Map<out K, V>?.isNullOrEmpty(): Boolean = this == null || isEmpty()
+
 /**
  * Returns the [Map] if its not `null`, or the empty [Map] otherwise.
  */