Merge pull request #114 from InsanusMokrassar/0.8.3

0.8.3

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## 0.8.3
+
+* `Common`:
+    * Ranges intersection functionality
+    * New type `Optional`
+* `Pagination`:
+    * `Pagination` now extends `ClosedRange<Int>`
+    * `Pagination` intersection functionality
+
 ## 0.8.2
 
 * `Versions`:

common/src/commonMain/kotlin/dev/inmo/micro_utils/common/Optional.kt

@@ -0,0 +1,75 @@
+@file:Suppress("unused")
+
+package dev.inmo.micro_utils.common
+
+import kotlinx.serialization.Serializable
+
+/**
+ * This type represents [T] as not only potentially nullable data, but also as a data which can not be presented. This
+ * type will be useful in cases when [T] is nullable and null as valuable data too in time of data absence should be
+ * presented by some third type.
+ *
+ * Let's imagine, you have nullable name in some database. In case when name is not nullable everything is clear - null
+ * will represent absence of row in the database. In case when name is nullable null will be a little bit dual-meaning,
+ * cause this null will say nothing about availability of the row (of course, it is exaggerated example)
+ *
+ * @see Optional.presented
+ * @see Optional.absent
+ * @see Optional.optional
+ * @see Optional.onPresented
+ * @see Optional.onAbsent
+ */
+@Serializable
+data class Optional<T> internal constructor(
+    internal val data: T?,
+    internal val dataPresented: Boolean
+) {
+    companion object {
+        /**
+         * Will create [Optional] with presented data
+         */
+        fun <T> presented(data: T) = Optional(data, true)
+        /**
+         * Will create [Optional] without data
+         */
+        fun <T> absent() = Optional<T>(null, false)
+    }
+}
+
+inline val <T> T.optional
+    get() = Optional.presented(this)
+
+/**
+ * Will call [block] when data presented ([Optional.dataPresented] == true)
+ */
+fun <T> Optional<T>.onPresented(block: (T) -> Unit): Optional<T> = apply {
+    if (dataPresented) { @Suppress("UNCHECKED_CAST") block(data as T) }
+}
+
+/**
+ * Will call [block] when data absent ([Optional.dataPresented] == false)
+ */
+fun <T> Optional<T>.onAbsent(block: () -> Unit): Optional<T> = apply {
+    if (!dataPresented) { block() }
+}
+
+/**
+ * Returns [Optional.data] if [Optional.dataPresented] of [this] is true, or null otherwise
+ */
+fun <T> Optional<T>.dataOrNull() = if (dataPresented) @Suppress("UNCHECKED_CAST") (data as T) else null
+
+/**
+ * Returns [Optional.data] if [Optional.dataPresented] of [this] is true, or throw [throwable] otherwise
+ */
+fun <T> Optional<T>.dataOrThrow(throwable: Throwable) = if (dataPresented) @Suppress("UNCHECKED_CAST") (data as T) else throw throwable
+
+
+/**
+ * Returns [Optional.data] if [Optional.dataPresented] of [this] is true, or call [block] and returns the result of it
+ */
+fun <T> Optional<T>.dataOrElse(block: () -> T) = if (dataPresented) @Suppress("UNCHECKED_CAST") (data as T) else block()
+
+/**
+ * Returns [Optional.data] if [Optional.dataPresented] of [this] is true, or call [block] and returns the result of it
+ */
+suspend fun <T> Optional<T>.dataOrElseSuspendable(block: suspend () -> T) = if (dataPresented) @Suppress("UNCHECKED_CAST") (data as T) else block()

common/src/commonMain/kotlin/dev/inmo/micro_utils/common/RangeIntersection.kt

@@ -0,0 +1,19 @@
+package dev.inmo.micro_utils.common
+
+fun <T : Comparable<T>> ClosedRange<T>.intersect(other: ClosedRange<T>): Pair<T, T>? = when {
+    start == other.start && endInclusive == other.endInclusive -> start to endInclusive
+    start > other.endInclusive || other.start > endInclusive -> null
+    else -> maxOf(start, other.start) to minOf(endInclusive, other.endInclusive)
+}
+
+fun IntRange.intersect(
+    other: IntRange
+): IntRange? = (this as ClosedRange<Int>).intersect(other as ClosedRange<Int>) ?.let {
+    it.first .. it.second
+}
+
+fun LongRange.intersect(
+    other: LongRange
+): LongRange? = (this as ClosedRange<Long>).intersect(other as ClosedRange<Long>) ?.let {
+    it.first .. it.second
+}

gradle.properties

@@ -45,5 +45,5 @@ dokka_version=1.5.31
 # Project data
 
 group=dev.inmo
-version=0.8.2
+version=0.8.3
-android_code_version=82
+android_code_version=83

pagination/common/build.gradle

@@ -5,3 +5,13 @@ plugins {
 }
 
 apply from: "$mppProjectWithSerializationPresetPath"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                api project(":micro_utils.common")
+            }
+        }
+    }
+}

pagination/common/src/commonMain/kotlin/dev/inmo/micro_utils/pagination/Pagination.kt

@@ -1,5 +1,6 @@
 package dev.inmo.micro_utils.pagination
 
+import dev.inmo.micro_utils.common.intersect
 import kotlin.math.ceil
 import kotlin.math.floor
 
@@ -9,7 +10,7 @@ import kotlin.math.floor
  * If you want to request something, you should use [SimplePagination]. If you need to return some result including
  * pagination - [PaginationResult]
  */
-interface Pagination {
+interface Pagination : ClosedRange<Int> {
     /**
      * Started with 0.
      * Number of page inside of pagination. Offset can be calculated as [page] * [size]
@@ -20,6 +21,17 @@ interface Pagination {
      * Size of current page. Offset can be calculated as [page] * [size]
      */
     val size: Int
+
+    override val start: Int
+        get() = page * size
+    override val endInclusive: Int
+        get() = lastIndex
+}
+
+fun Pagination.intersect(
+    other: Pagination
+): Pagination? = (this as ClosedRange<Int>).intersect(other as ClosedRange<Int>) ?.let {
+    PaginationByIndexes(it.first, it.second)
 }
 
 /**
@@ -32,7 +44,7 @@ inline val Pagination.isFirstPage
  * First number in index of objects. It can be used as offset for databases or other data sources
  */
 val Pagination.firstIndex: Int
-    get() = page * size
+    get() = start
 
 /**
  * Last number in index of objects. In fact, one [Pagination] object represent data in next range:
@@ -41,7 +53,7 @@ val Pagination.firstIndex: Int
  * you will retrieve [Pagination.firstIndex] == 10 and [Pagination.lastIndex] == 19. Here [Pagination.lastIndexExclusive] == 20
  */
 val Pagination.lastIndexExclusive: Int
-    get() = firstIndex + size
+    get() = endInclusive + 1
 
 /**
  * Last number in index of objects. In fact, one [Pagination] object represent data in next range:
@@ -50,7 +62,7 @@ val Pagination.lastIndexExclusive: Int
  * you will retrieve [Pagination.firstIndex] == 10 and [Pagination.lastIndex] == 19.
  */
 val Pagination.lastIndex: Int
-    get() = lastIndexExclusive - 1
+    get() = endInclusive
 
 /**
  * Calculates pages count for given [datasetSize]