Add groupingBy and eachCount sample.

js/js.libraries/src/core/generated/_ArraysJs.kt

@@ -7635,6 +7635,8 @@ public inline fun <K, V, M : MutableMap<in K, MutableList<V>>> CharArray.groupBy
 /**
  * Creates a [Grouping] source from an array to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <T, K> Array<out T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {

js/js.libraries/src/core/generated/_CollectionsJs.kt

@@ -1183,6 +1183,8 @@ public inline fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Iterable<T>.gr
 /**
  * Creates a [Grouping] source from a collection to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <T, K> Iterable<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {

js/js.libraries/src/core/generated/_SequencesJs.kt

@@ -648,6 +648,8 @@ public inline fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Sequence<T>.gr
 /**
  * Creates a [Grouping] source from a sequence to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <T, K> Sequence<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {

js/js.libraries/src/core/generated/_StringsJs.kt

@@ -705,6 +705,8 @@ public inline fun <K, V, M : MutableMap<in K, MutableList<V>>> CharSequence.grou
 /**
  * Creates a [Grouping] source from a char sequence to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each character.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <K> CharSequence.groupingBy(crossinline keySelector: (Char) -> K): Grouping<Char, K> {

libraries/stdlib/common/src/generated/_Arrays.kt

@@ -4448,6 +4448,8 @@ public header inline fun <K, V, M : MutableMap<in K, MutableList<V>>> CharArray.
 /**
  * Creates a [Grouping] source from an array to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public header inline fun <T, K> Array<out T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K>

libraries/stdlib/common/src/generated/_Collections.kt

@@ -590,6 +590,8 @@ public header inline fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Iterabl
 /**
  * Creates a [Grouping] source from a collection to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public header inline fun <T, K> Iterable<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K>

libraries/stdlib/common/src/generated/_Sequences.kt

@@ -362,6 +362,8 @@ public header inline fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Sequenc
 /**
  * Creates a [Grouping] source from a sequence to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public header inline fun <T, K> Sequence<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K>

libraries/stdlib/common/src/generated/_Strings.kt

@@ -425,6 +425,8 @@ public header inline fun <K, V, M : MutableMap<in K, MutableList<V>>> CharSequen
 /**
  * Creates a [Grouping] source from a char sequence to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each character.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public header inline fun <K> CharSequence.groupingBy(crossinline keySelector: (Char) -> K): Grouping<Char, K>

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

@@ -59,6 +59,18 @@ class Collections {
             // same content as in namesByTeam map, but the map is mutable
             assertTrue(mutableNamesByTeam == namesByTeam)
         }
+
+        @Sample
+        fun groupingByEachCount() {
+            val words = "one two three four five six seven eight nine ten".split(' ')
+            val frequenciesByFirstChar = words.groupingBy { it.first() }.eachCount()
+            println("Counting first letters:")
+            assertPrints(frequenciesByFirstChar, "{o=1, t=3, f=2, s=2, e=1, n=1}")
+
+            val moreWords = "eleven twelve".split(' ')
+            val moreFrequencies = moreWords.groupingBy { it.first() }.eachCountTo(frequenciesByFirstChar.toMutableMap())
+            assertPrints(moreFrequencies, "{o=1, t=4, f=2, s=2, e=2, n=1}")
+        }
     }
 
 }

libraries/stdlib/src/generated/_Arrays.kt

@@ -7716,6 +7716,8 @@ public inline fun <K, V, M : MutableMap<in K, MutableList<V>>> CharArray.groupBy
 /**
  * Creates a [Grouping] source from an array to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <T, K> Array<out T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {

libraries/stdlib/src/generated/_Collections.kt

@@ -1193,6 +1193,8 @@ public inline fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Iterable<T>.gr
 /**
  * Creates a [Grouping] source from a collection to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <T, K> Iterable<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {

libraries/stdlib/src/generated/_Sequences.kt

@@ -666,6 +666,8 @@ public inline fun <T, K, V, M : MutableMap<in K, MutableList<V>>> Sequence<T>.gr
 /**
  * Creates a [Grouping] source from a sequence to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each element.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <T, K> Sequence<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {

libraries/stdlib/src/generated/_Strings.kt

@@ -713,6 +713,8 @@ public inline fun <K, V, M : MutableMap<in K, MutableList<V>>> CharSequence.grou
 /**
  * Creates a [Grouping] source from a char sequence to be used later with one of group-and-fold operations
  * using the specified [keySelector] function to extract a key from each character.
+ * 
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public inline fun <K> CharSequence.groupingBy(crossinline keySelector: (Char) -> K): Grouping<Char, K> {

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

@@ -224,6 +224,8 @@ public inline fun <S, T : S, K, M : MutableMap<in K, S>> Grouping<T, K>.reduceTo
  * Groups elements from the [Grouping] source by key and counts elements in each group.
  *
  * @return a [Map] associating the key of each group with the count of elements in the group.
+ *
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 @JvmVersion
@@ -241,6 +243,8 @@ public fun <T, K> Grouping<T, K>.eachCount(): Map<K, Int> =
  * that value is used as an initial value of the counter for that group.
  *
  * @return the [destination] map associating the key of each group with the count of elements in the group.
+ *
+ * @sample samples.collections.Collections.Transformations.groupingByEachCount
  */
 @SinceKotlin("1.1")
 public fun <T, K, M : MutableMap<in K, Int>> Grouping<T, K>.eachCountTo(destination: M): M =

libraries/tools/kotlin-stdlib-gen/src/templates/Mapping.kt

@@ -402,6 +402,8 @@ fun mapping(): List<GenericFunction> {
             """
             Creates a [Grouping] source from ${f.collection.prefixWithArticle()} to be used later with one of group-and-fold operations
             using the specified [keySelector] function to extract a key from each ${f.element}.
+
+            @sample samples.collections.Collections.Transformations.groupingByEachCount
             """
         }