From 31151a9a7f798083da2f7435c46a8c1b1ddd8ee2 Mon Sep 17 00:00:00 2001
From: Andrew Golovashevich <landgrafhomyak@gmail.com>
Date: Tue, 25 Feb 2025 15:51:19 +0300
Subject: [PATCH] Some reducers

---
 .../db/serdha0/user_commons/reducers/Count.kt | 20 +++++++++++++
 .../serdha0/user_commons/reducers/HasRows.kt  | 21 ++++++++++++++
 .../db/serdha0/user_commons/reducers/Max.kt   | 28 +++++++++++++++++++
 .../db/serdha0/user_commons/reducers/Min.kt   | 28 +++++++++++++++++++
 4 files changed, 97 insertions(+)
 create mode 100644 src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Count.kt
 create mode 100644 src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/HasRows.kt
 create mode 100644 src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Max.kt
 create mode 100644 src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Min.kt

diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Count.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Count.kt
new file mode 100644
index 0000000..a30d9ea
--- /dev/null
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Count.kt
@@ -0,0 +1,20 @@
+package ru.landgrafhomyak.db.serdha0.user_commons.reducers
+
+import ru.landgrafhomyak.db.serdha0.api.misc.Reducer
+import ru.landgrafhomyak.db.serdha0.api.runtime.InputRow
+import ru.landgrafhomyak.db.serdha0.api.runtime.OutputRow
+import ru.landgrafhomyak.db.serdha0.user_commons.types.U_INT_64
+
+public class Count private constructor(context: Reducer.Constructor.Scope<Count>) : Reducer.Action<Count> {
+	@Suppress("PropertyName", "MemberVisibilityCanBePrivate")
+	public val C_Counter: Reducer.OutputColumn<ULong, U_INT_64, Count> = context.outputColumn("counter", context.types.U_INT_64, 0u)
+
+	override fun calculate(acc: OutputRow<Count>, row: OutputRow<Count>, newAcc: InputRow<Count>) {
+		newAcc[this.C_Counter] = acc[this.C_Counter] + 1u
+	}
+
+	public object Constructor : Reducer.Constructor<Count> {
+		override fun createReducer(context: Reducer.Constructor.Scope<Count>): Reducer.Action<Count> =
+			Count(context)
+	}
+}
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/HasRows.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/HasRows.kt
new file mode 100644
index 0000000..dafefeb
--- /dev/null
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/HasRows.kt
@@ -0,0 +1,21 @@
+package ru.landgrafhomyak.db.serdha0.user_commons.reducers
+
+import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
+import ru.landgrafhomyak.db.serdha0.api.misc.Reducer
+import ru.landgrafhomyak.db.serdha0.api.runtime.InputRow
+import ru.landgrafhomyak.db.serdha0.api.runtime.OutputRow
+
+public class HasRows private constructor(context: Reducer.Constructor.Scope<HasRows>) : Reducer.Action<HasRows> {
+	@Suppress("PropertyName", "MemberVisibilityCanBePrivate")
+	public val C_HasRows: Reducer.OutputColumn<Boolean, DatabaseType.BOOLEAN, HasRows> =
+		context.outputColumn("flag", context.types.BOOLEAN, false)
+
+	override fun calculate(acc: OutputRow<HasRows>, row: OutputRow<HasRows>, newAcc: InputRow<HasRows>) {
+		newAcc[this.C_HasRows] = true
+	}
+
+	public object Constructor : Reducer.Constructor<HasRows> {
+		override fun createReducer(context: Reducer.Constructor.Scope<HasRows>): Reducer.Action<HasRows> =
+			HasRows(context)
+	}
+}
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Max.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Max.kt
new file mode 100644
index 0000000..03ad1b3
--- /dev/null
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Max.kt
@@ -0,0 +1,28 @@
+package ru.landgrafhomyak.db.serdha0.user_commons.reducers
+
+import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
+import ru.landgrafhomyak.db.serdha0.api.misc.Reducer
+import ru.landgrafhomyak.db.serdha0.api.runtime.InputRow
+import ru.landgrafhomyak.db.serdha0.api.runtime.OutputRow
+
+public class Max<RT, DT : DatabaseType._VirtualType<RT, *, *>> private constructor(
+	context: Reducer.Constructor.Scope<Max<RT, DT>>,
+	private val _type: DT
+) : Reducer.Action<Max<RT, DT>> {
+	@Suppress("PropertyName", "MemberVisibilityCanBePrivate")
+	public val C_MaxValue: Reducer.BidirectionalColumn<RT, DT, Max<RT, DT>> = context.bidirectionalColumn("max_value", this._type)
+
+	override fun calculate(acc: OutputRow<Max<RT, DT>>, row: OutputRow<Max<RT, DT>>, newAcc: InputRow<Max<RT, DT>>) {
+		val accumulatedValue = acc[this.C_MaxValue]
+		val newValue = row[this.C_MaxValue]
+		if (this._type._compare(accumulatedValue, newValue) < 0)
+			newAcc[this.C_MaxValue] = newValue
+		else
+			newAcc[this.C_MaxValue] = accumulatedValue
+	}
+
+	public class Constructor<RT, DT : DatabaseType._VirtualType<RT, *, *>>(private val type: DT) : Reducer.Constructor<Max<RT, DT>> {
+		override fun createReducer(context: Reducer.Constructor.Scope<Max<RT, DT>>): Reducer.Action<Max<RT, DT>> =
+			Max(context, this.type)
+	}
+}
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Min.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Min.kt
new file mode 100644
index 0000000..55ca1d5
--- /dev/null
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/user_commons/reducers/Min.kt
@@ -0,0 +1,28 @@
+package ru.landgrafhomyak.db.serdha0.user_commons.reducers
+
+import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
+import ru.landgrafhomyak.db.serdha0.api.misc.Reducer
+import ru.landgrafhomyak.db.serdha0.api.runtime.InputRow
+import ru.landgrafhomyak.db.serdha0.api.runtime.OutputRow
+
+public class Min<RT, DT : DatabaseType._VirtualType<RT, *, *>> private constructor(
+	context: Reducer.Constructor.Scope<Min<RT, DT>>,
+	private val _type: DT
+) : Reducer.Action<Min<RT, DT>> {
+	@Suppress("PropertyName", "MemberVisibilityCanBePrivate")
+	public val C_MinValue: Reducer.BidirectionalColumn<RT, DT, Min<RT, DT>> = context.bidirectionalColumn("min_value", this._type)
+
+	override fun calculate(acc: OutputRow<Min<RT, DT>>, row: OutputRow<Min<RT, DT>>, newAcc: InputRow<Min<RT, DT>>) {
+		val accumulatedValue = acc[this.C_MinValue]
+		val newValue = row[this.C_MinValue]
+		if (this._type._compare(accumulatedValue, newValue) > 0)
+			newAcc[this.C_MinValue] = newValue
+		else
+			newAcc[this.C_MinValue] = accumulatedValue
+	}
+
+	public class Constructor<RT, DT : DatabaseType._VirtualType<RT, *, *>>(private val type: DT) : Reducer.Constructor<Min<RT, DT>> {
+		override fun createReducer(context: Reducer.Constructor.Scope<Min<RT, DT>>): Reducer.Action<Min<RT, DT>> =
+			Min(context, this.type)
+	}
+}
\ No newline at end of file