describe() fixes

core/api/core.api

@@ -2691,7 +2691,7 @@ public abstract interface class org/jetbrains/kotlinx/dataframe/api/ColumnDescri
 	public abstract fun getPath ()Lorg/jetbrains/kotlinx/dataframe/columns/ColumnPath;
 	public abstract fun getStd ()D
 	public abstract fun getTop ()Ljava/lang/Object;
-	public abstract fun getType ()Lkotlin/reflect/KType;
+	public abstract fun getType ()Ljava/lang/String;
 	public abstract fun getUnique ()I
 }
 
@@ -2719,7 +2719,7 @@ public final class org/jetbrains/kotlinx/dataframe/api/ColumnDescription_Extensi
 	public static final fun ColumnDescription_top (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
 	public static final fun ColumnDescription_top (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Ljava/lang/Object;
 	public static final fun ColumnDescription_type (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
-	public static final fun ColumnDescription_type (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Lkotlin/reflect/KType;
+	public static final fun ColumnDescription_type (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Ljava/lang/String;
 	public static final fun ColumnDescription_unique (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
 	public static final fun ColumnDescription_unique (Lorg/jetbrains/kotlinx/dataframe/DataRow;)I
 	public static final fun NullableColumnDescription_count (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
@@ -2745,7 +2745,7 @@ public final class org/jetbrains/kotlinx/dataframe/api/ColumnDescription_Extensi
 	public static final fun NullableColumnDescription_top (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
 	public static final fun NullableColumnDescription_top (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Ljava/lang/Object;
 	public static final fun NullableColumnDescription_type (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
-	public static final fun NullableColumnDescription_type (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Lkotlin/reflect/KType;
+	public static final fun NullableColumnDescription_type (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Ljava/lang/String;
 	public static final fun NullableColumnDescription_unique (Lorg/jetbrains/kotlinx/dataframe/ColumnsContainer;)Lorg/jetbrains/kotlinx/dataframe/DataColumn;
 	public static final fun NullableColumnDescription_unique (Lorg/jetbrains/kotlinx/dataframe/DataRow;)Ljava/lang/Integer;
 }
@@ -4146,9 +4146,11 @@ public final class org/jetbrains/kotlinx/dataframe/api/DataColumnArithmeticsKt {
 }
 
 public final class org/jetbrains/kotlinx/dataframe/api/DataColumnTypeKt {
+	public static final fun isBigNumber (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
 	public static final fun isColumnGroup (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
 	public static final fun isComparable (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
 	public static final fun isFrameColumn (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
+	public static final fun isInterComparable (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
 	public static final fun isList (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
 	public static final fun isNumber (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
 	public static final fun isPrimitive (Lorg/jetbrains/kotlinx/dataframe/DataColumn;)Z
@@ -10771,6 +10773,7 @@ public final class org/jetbrains/kotlinx/dataframe/math/BasicStats {
 
 public final class org/jetbrains/kotlinx/dataframe/math/MeanKt {
 	public static final fun bigDecimalMean (Ljava/lang/Iterable;)D
+	public static final fun bigIntegerMean (Ljava/lang/Iterable;)D
 	public static final fun byteMean (Ljava/lang/Iterable;)D
 	public static final fun doubleMean (Ljava/lang/Iterable;Z)D
 	public static synthetic fun doubleMean$default (Ljava/lang/Iterable;ZILjava/lang/Object;)D
@@ -10794,6 +10797,8 @@ public final class org/jetbrains/kotlinx/dataframe/math/MedianKt {
 public final class org/jetbrains/kotlinx/dataframe/math/StdKt {
 	public static final fun bigDecimalStd (Ljava/lang/Iterable;I)D
 	public static synthetic fun bigDecimalStd$default (Ljava/lang/Iterable;IILjava/lang/Object;)D
+	public static final fun bigIntegerStd (Ljava/lang/Iterable;I)D
+	public static synthetic fun bigIntegerStd$default (Ljava/lang/Iterable;IILjava/lang/Object;)D
 	public static final fun doubleStd (Ljava/lang/Iterable;ZI)D
 	public static synthetic fun doubleStd$default (Ljava/lang/Iterable;ZIILjava/lang/Object;)D
 	public static final fun floatStd (Ljava/lang/Iterable;ZI)D
@@ -10808,6 +10813,7 @@ public final class org/jetbrains/kotlinx/dataframe/math/StdKt {
 
 public final class org/jetbrains/kotlinx/dataframe/math/StdMeanKt {
 	public static final fun bigDecimalVarianceAndMean (Ljava/lang/Iterable;)Lorg/jetbrains/kotlinx/dataframe/math/BasicStats;
+	public static final fun bigIntegerVarianceAndMean (Ljava/lang/Iterable;)Lorg/jetbrains/kotlinx/dataframe/math/BasicStats;
 	public static final fun doubleVarianceAndMean (Ljava/lang/Iterable;Z)Lorg/jetbrains/kotlinx/dataframe/math/BasicStats;
 	public static synthetic fun doubleVarianceAndMean$default (Ljava/lang/Iterable;ZILjava/lang/Object;)Lorg/jetbrains/kotlinx/dataframe/math/BasicStats;
 	public static final fun floatVarianceAndMean (Ljava/lang/Iterable;Z)Lorg/jetbrains/kotlinx/dataframe/math/BasicStats;
@@ -10818,8 +10824,10 @@ public final class org/jetbrains/kotlinx/dataframe/math/StdMeanKt {
 
 public final class org/jetbrains/kotlinx/dataframe/math/SumKt {
 	public static final fun sum (Ljava/lang/Iterable;)Ljava/math/BigDecimal;
+	public static final fun sum (Ljava/lang/Iterable;)Ljava/math/BigInteger;
 	public static final fun sum (Ljava/lang/Iterable;Lkotlin/reflect/KType;)Ljava/lang/Number;
 	public static final fun sum (Lkotlin/sequences/Sequence;)Ljava/math/BigDecimal;
+	public static final fun sum (Lkotlin/sequences/Sequence;)Ljava/math/BigInteger;
 	public static final fun sumNullableT (Ljava/lang/Iterable;Lkotlin/reflect/KType;)Ljava/lang/Number;
 	public static final fun sumOf (Ljava/lang/Iterable;Lkotlin/reflect/KType;Lkotlin/jvm/functions/Function1;)Ljava/lang/Number;
 }

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/DataColumnType.kt

@@ -11,6 +11,11 @@ import org.jetbrains.kotlinx.dataframe.impl.isNothing
 import org.jetbrains.kotlinx.dataframe.impl.projectTo
 import org.jetbrains.kotlinx.dataframe.type
 import org.jetbrains.kotlinx.dataframe.typeClass
+import org.jetbrains.kotlinx.dataframe.util.IS_COMPARABLE
+import org.jetbrains.kotlinx.dataframe.util.IS_COMPARABLE_REPLACE
+import org.jetbrains.kotlinx.dataframe.util.IS_INTER_COMPARABLE_IMPORT
+import java.math.BigDecimal
+import java.math.BigInteger
 import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.contract
 import kotlin.reflect.KClass
@@ -44,13 +49,26 @@ public inline fun <reified T> AnyCol.isType(): Boolean = type() == typeOf<T>()
 
 public fun AnyCol.isNumber(): Boolean = isSubtypeOf<Number?>()
 
+public fun AnyCol.isBigNumber(): Boolean = isSubtypeOf<BigInteger?>() || isSubtypeOf<BigDecimal?>()
+
 public fun AnyCol.isList(): Boolean = typeClass == List::class
 
+/** @include [isInterComparable] */
+@Deprecated(
+    message = IS_COMPARABLE,
+    replaceWith = ReplaceWith(IS_COMPARABLE_REPLACE, IS_INTER_COMPARABLE_IMPORT),
+    level = DeprecationLevel.WARNING,
+)
+public fun AnyCol.isComparable(): Boolean = isInterComparable()
+
 /**
- * Returns `true` if [this] column is comparable, i.e. its type is a subtype of [Comparable] and its
- * type argument is not [Nothing].
+ * Returns `true` if [this] column is inter-comparable, i.e.
+ * its elements can be compared with each other.
+ *
+ * Technically, this means the elements' common type is a subtype of [Comparable] with
+ * the type argument not being [Nothing].
  */
-public fun AnyCol.isComparable(): Boolean =
+public fun AnyCol.isInterComparable(): Boolean =
     isSubtypeOf<Comparable<*>?>() &&
         type().projectTo(Comparable::class).arguments[0].let {
             it != KTypeProjection.STAR &&

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/cumSum.kt

@@ -5,10 +5,13 @@ import org.jetbrains.kotlinx.dataframe.ColumnsSelector
 import org.jetbrains.kotlinx.dataframe.DataColumn
 import org.jetbrains.kotlinx.dataframe.DataFrame
 import org.jetbrains.kotlinx.dataframe.columns.toColumnSet
+import org.jetbrains.kotlinx.dataframe.impl.nothingType
+import org.jetbrains.kotlinx.dataframe.impl.nullableNothingType
 import org.jetbrains.kotlinx.dataframe.math.cumSum
 import org.jetbrains.kotlinx.dataframe.math.defaultCumSumSkipNA
 import org.jetbrains.kotlinx.dataframe.typeClass
 import java.math.BigDecimal
+import java.math.BigInteger
 import kotlin.reflect.KProperty
 import kotlin.reflect.typeOf
 
@@ -17,20 +20,59 @@ import kotlin.reflect.typeOf
 public fun <T : Number?> DataColumn<T>.cumSum(skipNA: Boolean = defaultCumSumSkipNA): DataColumn<T> =
     when (type()) {
         typeOf<Double>() -> cast<Double>().cumSum(skipNA).cast()
+
         typeOf<Double?>() -> cast<Double?>().cumSum(skipNA).cast()
+
         typeOf<Float>() -> cast<Float>().cumSum(skipNA).cast()
+
         typeOf<Float?>() -> cast<Float?>().cumSum(skipNA).cast()
+
         typeOf<Int>() -> cast<Int>().cumSum().cast()
+
+        // TODO cumSum for Byte returns Int but is converted back to T: Byte, Issue #558
+        typeOf<Byte>() -> cast<Byte>().cumSum().map { it.toByte() }.cast()
+
+        // TODO cumSum for Short returns Int but is converted back to T: Short, Issue #558
+        typeOf<Short>() -> cast<Short>().cumSum().map { it.toShort() }.cast()
+
         typeOf<Int?>() -> cast<Int?>().cumSum(skipNA).cast()
+
+        // TODO cumSum for Byte? returns Int? but is converted back to T: Byte?, Issue #558
+        typeOf<Byte?>() -> cast<Byte?>().cumSum(skipNA).map { it?.toByte() }.cast()
+
+        // TODO cumSum for Short? returns Int? but is converted back to T: Short?, Issue #558
+        typeOf<Short?>() -> cast<Short?>().cumSum(skipNA).map { it?.toShort() }.cast()
+
         typeOf<Long>() -> cast<Long>().cumSum().cast()
+
         typeOf<Long?>() -> cast<Long?>().cumSum(skipNA).cast()
+
+        typeOf<BigInteger>() -> cast<BigInteger>().cumSum().cast()
+
+        typeOf<BigInteger?>() -> cast<BigInteger?>().cumSum(skipNA).cast()
+
         typeOf<BigDecimal>() -> cast<BigDecimal>().cumSum().cast()
+
         typeOf<BigDecimal?>() -> cast<BigDecimal?>().cumSum(skipNA).cast()
+
         typeOf<Number?>(), typeOf<Number>() -> convertToDouble().cumSum(skipNA).cast()
+
+        // Cumsum for empty column or column with just null is itself
+        nothingType, nullableNothingType -> this
+
         else -> error("Cumsum for type ${type()} is not supported")
     }
 
-private val supportedClasses = setOf(Double::class, Float::class, Int::class, Long::class, BigDecimal::class)
+private val supportedClasses = setOf(
+    Double::class,
+    Float::class,
+    Int::class,
+    Byte::class,
+    Short::class,
+    Long::class,
+    BigInteger::class,
+    BigDecimal::class,
+)
 
 // endregion
 

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/describe.kt

@@ -9,14 +9,13 @@ import org.jetbrains.kotlinx.dataframe.columns.ColumnReference
 import org.jetbrains.kotlinx.dataframe.columns.toColumnSet
 import org.jetbrains.kotlinx.dataframe.impl.api.describeImpl
 import kotlin.reflect.KProperty
-import kotlin.reflect.KType
 
 // region DataSchema
 @DataSchema
 public interface ColumnDescription {
     public val name: String
     public val path: ColumnPath
-    public val type: KType
+    public val type: String
     public val count: Int
     public val unique: Int
     public val nulls: Int

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/max.kt

@@ -11,7 +11,7 @@ import org.jetbrains.kotlinx.dataframe.columns.ColumnReference
 import org.jetbrains.kotlinx.dataframe.columns.toColumnSet
 import org.jetbrains.kotlinx.dataframe.columns.values
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators.Aggregators
-import org.jetbrains.kotlinx.dataframe.impl.aggregation.comparableColumns
+import org.jetbrains.kotlinx.dataframe.impl.aggregation.interComparableColumns
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateAll
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateFor
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateOfDelegated
@@ -52,7 +52,7 @@ public inline fun <reified T : Comparable<T>> AnyRow.rowMaxOf(): T = rowMaxOfOrN
 
 // region DataFrame
 
-public fun <T> DataFrame<T>.max(): DataRow<T> = maxFor(comparableColumns())
+public fun <T> DataFrame<T>.max(): DataRow<T> = maxFor(interComparableColumns())
 
 public fun <T, C : Comparable<C>> DataFrame<T>.maxFor(columns: ColumnsForAggregateSelector<T, C?>): DataRow<T> =
     Aggregators.max.aggregateFor(this, columns)
@@ -121,7 +121,7 @@ public fun <T, C : Comparable<C>> DataFrame<T>.maxByOrNull(column: KProperty<C?>
 
 // region GroupBy
 
-public fun <T> Grouped<T>.max(): DataFrame<T> = maxFor(comparableColumns())
+public fun <T> Grouped<T>.max(): DataFrame<T> = maxFor(interComparableColumns())
 
 public fun <T, C : Comparable<C>> Grouped<T>.maxFor(columns: ColumnsForAggregateSelector<T, C?>): DataFrame<T> =
     Aggregators.max.aggregateFor(this, columns)
@@ -218,7 +218,7 @@ public fun <T, C : Comparable<C>> Pivot<T>.maxBy(column: KProperty<C?>): Reduced
 
 // region PivotGroupBy
 
-public fun <T> PivotGroupBy<T>.max(separate: Boolean = false): DataFrame<T> = maxFor(separate, comparableColumns())
+public fun <T> PivotGroupBy<T>.max(separate: Boolean = false): DataFrame<T> = maxFor(separate, interComparableColumns())
 
 public fun <T, R : Comparable<R>> PivotGroupBy<T>.maxFor(
     separate: Boolean = false,

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/median.kt

@@ -11,7 +11,7 @@ import org.jetbrains.kotlinx.dataframe.columns.ColumnReference
 import org.jetbrains.kotlinx.dataframe.columns.toColumnSet
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators.Aggregators
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators.cast
-import org.jetbrains.kotlinx.dataframe.impl.aggregation.comparableColumns
+import org.jetbrains.kotlinx.dataframe.impl.aggregation.interComparableColumns
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateAll
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateFor
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateOf
@@ -53,7 +53,7 @@ public inline fun <reified T : Comparable<T>> AnyRow.rowMedianOf(): T =
 
 // region DataFrame
 
-public fun <T> DataFrame<T>.median(): DataRow<T> = medianFor(comparableColumns())
+public fun <T> DataFrame<T>.median(): DataRow<T> = medianFor(interComparableColumns())
 
 public fun <T, C : Comparable<C>> DataFrame<T>.medianFor(columns: ColumnsForAggregateSelector<T, C?>): DataRow<T> =
     Aggregators.median.aggregateFor(this, columns)
@@ -96,7 +96,7 @@ public inline fun <T, reified R : Comparable<R>> DataFrame<T>.medianOf(
 
 // region GroupBy
 
-public fun <T> Grouped<T>.median(): DataFrame<T> = medianFor(comparableColumns())
+public fun <T> Grouped<T>.median(): DataFrame<T> = medianFor(interComparableColumns())
 
 public fun <T, C : Comparable<C>> Grouped<T>.medianFor(columns: ColumnsForAggregateSelector<T, C?>): DataFrame<T> =
     Aggregators.median.aggregateFor(this, columns)
@@ -134,7 +134,7 @@ public inline fun <T, reified R : Comparable<R>> Grouped<T>.medianOf(
 
 // region Pivot
 
-public fun <T> Pivot<T>.median(separate: Boolean = false): DataRow<T> = medianFor(separate, comparableColumns())
+public fun <T> Pivot<T>.median(separate: Boolean = false): DataRow<T> = medianFor(separate, interComparableColumns())
 
 public fun <T, C : Comparable<C>> Pivot<T>.medianFor(
     separate: Boolean = false,
@@ -174,7 +174,7 @@ public inline fun <T, reified R : Comparable<R>> Pivot<T>.medianOf(
 // region PivotGroupBy
 
 public fun <T> PivotGroupBy<T>.median(separate: Boolean = false): DataFrame<T> =
-    medianFor(separate, comparableColumns())
+    medianFor(separate, interComparableColumns())
 
 public fun <T, C : Comparable<C>> PivotGroupBy<T>.medianFor(
     separate: Boolean = false,

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/min.kt

@@ -11,7 +11,7 @@ import org.jetbrains.kotlinx.dataframe.columns.ColumnReference
 import org.jetbrains.kotlinx.dataframe.columns.toColumnSet
 import org.jetbrains.kotlinx.dataframe.columns.values
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.aggregators.Aggregators
-import org.jetbrains.kotlinx.dataframe.impl.aggregation.comparableColumns
+import org.jetbrains.kotlinx.dataframe.impl.aggregation.interComparableColumns
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateAll
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateFor
 import org.jetbrains.kotlinx.dataframe.impl.aggregation.modes.aggregateOfDelegated
@@ -52,7 +52,7 @@ public inline fun <reified T : Comparable<T>> AnyRow.rowMinOf(): T = rowMinOfOrN
 
 // region DataFrame
 
-public fun <T> DataFrame<T>.min(): DataRow<T> = minFor(comparableColumns())
+public fun <T> DataFrame<T>.min(): DataRow<T> = minFor(interComparableColumns())
 
 public fun <T, C : Comparable<C>> DataFrame<T>.minFor(columns: ColumnsForAggregateSelector<T, C?>): DataRow<T> =
     Aggregators.min.aggregateFor(this, columns)
@@ -121,7 +121,7 @@ public fun <T, C : Comparable<C>> DataFrame<T>.minByOrNull(column: KProperty<C?>
 
 // region GroupBy
 
-public fun <T> Grouped<T>.min(): DataFrame<T> = minFor(comparableColumns())
+public fun <T> Grouped<T>.min(): DataFrame<T> = minFor(interComparableColumns())
 
 public fun <T, C : Comparable<C>> Grouped<T>.minFor(columns: ColumnsForAggregateSelector<T, C?>): DataFrame<T> =
     Aggregators.min.aggregateFor(this, columns)
@@ -219,7 +219,7 @@ public fun <T, C : Comparable<C>> Pivot<T>.minBy(column: KProperty<C?>): Reduced
 
 // region PivotGroupBy
 
-public fun <T> PivotGroupBy<T>.min(separate: Boolean = false): DataFrame<T> = minFor(separate, comparableColumns())
+public fun <T> PivotGroupBy<T>.min(separate: Boolean = false): DataFrame<T> = minFor(separate, interComparableColumns())
 
 public fun <T, R : Comparable<R>> PivotGroupBy<T>.minFor(
     separate: Boolean = false,

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/typeConversions.kt

@@ -83,7 +83,7 @@ public fun DataColumn<Any>.asNumbers(): ValueColumn<Number> {
 }
 
 public fun <T> DataColumn<T>.asComparable(): DataColumn<Comparable<T>> {
-    require(isComparable())
+    require(isInterComparable())
     return this as DataColumn<Comparable<T>>
 }
 

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/TypeUtils.kt

@@ -11,6 +11,8 @@ import org.jetbrains.kotlinx.dataframe.DataRow
 import org.jetbrains.kotlinx.dataframe.api.Infer
 import org.jetbrains.kotlinx.dataframe.impl.columns.createColumnGuessingType
 import org.jetbrains.kotlinx.dataframe.util.GUESS_VALUE_TYPE
+import java.math.BigDecimal
+import java.math.BigInteger
 import kotlin.reflect.KClass
 import kotlin.reflect.KType
 import kotlin.reflect.KTypeParameter
@@ -29,6 +31,7 @@ import kotlin.reflect.full.superclasses
 import kotlin.reflect.full.withNullability
 import kotlin.reflect.jvm.jvmErasure
 import kotlin.reflect.typeOf
+import kotlin.toBigDecimal as toBigDecimalKotlin
 
 internal inline fun <reified T> KClass<*>.createTypeUsing() = typeOf<T>().projectTo(this)
 
@@ -546,12 +549,10 @@ internal fun guessValueType(
 internal val KType.isNothing: Boolean
     get() = classifier == Nothing::class
 
-internal fun nothingType(nullable: Boolean): KType =
-    if (nullable) {
-        typeOf<List<Nothing?>>()
-    } else {
-        typeOf<List<Nothing>>()
-    }.arguments.first().type!!
+internal val nothingType: KType = typeOf<List<Nothing>>().arguments.first().type!!
+internal val nullableNothingType: KType = typeOf<List<Nothing?>>().arguments.first().type!!
+
+internal fun nothingType(nullable: Boolean): KType = if (nullable) nullableNothingType else nothingType
 
 @OptIn(ExperimentalUnsignedTypes::class)
 private val primitiveArrayClasses = setOf(
@@ -646,3 +647,18 @@ internal fun Any.asArrayAsListOrNull(): List<*>? =
         is Array<*> -> asList()
         else -> null
     }
+
+internal fun Any.isBigNumber(): Boolean = this is BigInteger || this is BigDecimal
+
+internal fun Number.toBigDecimal(): BigDecimal =
+    when (this) {
+        is BigDecimal -> this
+        is BigInteger -> this.toBigDecimalKotlin()
+        is Int -> this.toBigDecimalKotlin()
+        is Byte -> this.toInt().toBigDecimalKotlin()
+        is Short -> this.toInt().toBigDecimalKotlin()
+        is Long -> this.toBigDecimalKotlin()
+        is Float -> this.toBigDecimalKotlin()
+        is Double -> this.toBigDecimalKotlin()
+        else -> BigDecimal(this.toString())
+    }