refactored AggregatorProvider back

Author: Jolanrensen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/aggregation/aggregators/Aggregator.kt

@@ -78,7 +78,7 @@ internal class Aggregator<in Value : Any, out Return : Any?>(
             aggregationHandler: AggregatorAggregationHandler<Value, Return>,
             inputHandler: AggregatorInputHandler<Value, Return>,
             multipleColumnsHandler: AggregatorMultipleColumnsHandler<Value, Return>,
-        ): AggregatorProvider<Aggregator<Value, Return>> =
+        ): AggregatorProvider<Value, Return> =
             AggregatorProvider { name ->
                 Aggregator(
                     aggregationHandler = aggregationHandler,

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/aggregation/aggregators/AggregatorOptionSwitch.kt

@@ -7,14 +7,14 @@ package org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators
  * @see AggregatorOptionSwitch2
  */
 @PublishedApi
-internal class AggregatorOptionSwitch1<in Param1, out AggregatorType : Aggregator<*, *>>(
+internal class AggregatorOptionSwitch1<in Param1, in Value : Any, out Return : Any?>(
     val name: String,
-    val getAggregator: (param1: Param1) -> AggregatorProvider<AggregatorType>,
+    val getAggregator: (param1: Param1) -> AggregatorProvider<Value, Return>,
 ) {
 
-    private val cache: MutableMap<Param1, AggregatorType> = mutableMapOf()
+    private val cache: MutableMap<Param1, Aggregator<Value, Return>> = mutableMapOf()
 
-    operator fun invoke(param1: Param1): AggregatorType =
+    operator fun invoke(param1: Param1): Aggregator<Value, Return> =
         cache.getOrPut(param1) {
             getAggregator(param1).create(name)
         }
@@ -31,8 +31,8 @@ internal class AggregatorOptionSwitch1<in Param1, out AggregatorType : Aggregato
          *   MyAggregator.Factory(param1)
          * }
          */
-        fun <Param1, AggregatorType : Aggregator<*, *>> Factory(
-            getAggregator: (param1: Param1) -> AggregatorProvider<AggregatorType>,
+        fun <Param1, Value : Any, Return : Any?> Factory(
+            getAggregator: (param1: Param1) -> AggregatorProvider<Value, Return>,
         ) = Provider { name -> AggregatorOptionSwitch1(name, getAggregator) }
     }
 }
@@ -44,14 +44,14 @@ internal class AggregatorOptionSwitch1<in Param1, out AggregatorType : Aggregato
  * @see AggregatorOptionSwitch1
  */
 @PublishedApi
-internal class AggregatorOptionSwitch2<in Param1, in Param2, out AggregatorType : Aggregator<*, *>>(
+internal class AggregatorOptionSwitch2<in Param1, in Param2, in Value : Any, out Return : Any?>(
     val name: String,
-    val getAggregator: (param1: Param1, param2: Param2) -> AggregatorProvider<AggregatorType>,
+    val getAggregator: (param1: Param1, param2: Param2) -> AggregatorProvider<Value, Return>,
 ) {
 
-    private val cache: MutableMap<Pair<Param1, Param2>, AggregatorType> = mutableMapOf()
+    private val cache: MutableMap<Pair<Param1, Param2>, Aggregator<Value, Return>> = mutableMapOf()
 
-    operator fun invoke(param1: Param1, param2: Param2): AggregatorType =
+    operator fun invoke(param1: Param1, param2: Param2): Aggregator<Value, Return> =
         cache.getOrPut(param1 to param2) {
             getAggregator(param1, param2).create(name)
         }
@@ -68,8 +68,8 @@ internal class AggregatorOptionSwitch2<in Param1, in Param2, out AggregatorType
          *   MyAggregator.Factory(param1, param2)
          * }
          */
-        fun <Param1, Param2, AggregatorType : Aggregator<*, *>> Factory(
-            getAggregator: (param1: Param1, param2: Param2) -> AggregatorProvider<AggregatorType>,
+        fun <Param1, Param2, Value : Any, Return : Any?> Factory(
+            getAggregator: (param1: Param1, param2: Param2) -> AggregatorProvider<Value, Return>,
         ) = Provider { name -> AggregatorOptionSwitch2(name, getAggregator) }
     }
 }

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/aggregation/aggregators/AggregatorProvider.kt

@@ -24,7 +24,5 @@ internal operator fun <T> Provider<T>.getValue(obj: Any?, property: KProperty<*>
  * ```kt
  * val myAggregator by MyAggregator.Factory
  * ```
- *
- * TODO change back to AggregatorProvider<Value, Return>
  */
-internal fun interface AggregatorProvider<out AggregatorType : Aggregator<*, *>> : Provider<AggregatorType>
+internal fun interface AggregatorProvider<in Value : Any, out Return : Any?> : Provider<Aggregator<Value, Return>>

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/aggregation/aggregators/Aggregators.kt

@@ -30,12 +30,11 @@ internal object Aggregators {
     private fun <Value : Return & Any, Return : Any?> twoStepSelecting(
         reducer: Reducer<Value, Return>,
         indexOfResult: IndexOfResult<Value>,
-    ): AggregatorProvider<Aggregator<Value, Return>> =
-        Aggregator(
-            aggregationHandler = SelectingAggregationHandler(reducer, indexOfResult, preserveReturnTypeNullIfEmpty),
-            inputHandler = AnyInputHandler(),
-            multipleColumnsHandler = TwoStepMultipleColumnsHandler(),
-        )
+    ) = Aggregator(
+        aggregationHandler = SelectingAggregationHandler(reducer, indexOfResult, preserveReturnTypeNullIfEmpty),
+        inputHandler = AnyInputHandler(),
+        multipleColumnsHandler = TwoStepMultipleColumnsHandler(),
+    )
 
     /**
      * Factory for a simple aggregator that changes the type of the input values.
@@ -95,13 +94,13 @@ internal object Aggregators {
     )
 
     /** @include [AggregatorOptionSwitch1] */
-    private fun <Param1, AggregatorType : Aggregator<*, *>> withOneOption(
-        getAggregator: (Param1) -> AggregatorProvider<AggregatorType>,
+    private fun <Param1, Value : Any, Return : Any?> withOneOption(
+        getAggregator: (Param1) -> AggregatorProvider<Value, Return>,
     ) = AggregatorOptionSwitch1.Factory(getAggregator)
 
     /** @include [AggregatorOptionSwitch2] */
-    private fun <Param1, Param2, AggregatorType : Aggregator<*, *>> withTwoOptions(
-        getAggregator: (Param1, Param2) -> AggregatorProvider<AggregatorType>,
+    private fun <Param1, Param2, Value : Any, Return : Any?> withTwoOptions(
+        getAggregator: (Param1, Param2) -> AggregatorProvider<Value, Return>,
     ) = AggregatorOptionSwitch2.Factory(getAggregator)
 
     // T: Comparable<T> -> T?