either

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## 0.7.4
 
+* `Common`:
+    * New type `Either`
+
 ## 0.7.3
 
 * `Versions`:

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

@@ -0,0 +1,45 @@
+package dev.inmo.micro_utils.common
+
+/**
+ * Realization of this interface will contains at least one not null - [t1] or [t2]
+ *
+ * @see EitherFirst
+ * @see EitherSecond
+ * @see Either.Companion.first
+ * @see Either.Companion.second
+ * @see Either.onFirst
+ * @see Either.onSecond
+ */
+sealed interface Either<T1, T2> {
+    val t1: T1?
+    val t2: T2?
+
+    companion object
+}
+
+data class EitherFirst<T1, T2>(
+    override val t1: T1
+) : Either<T1, T2> {
+    override val t2: T2?
+        get() = null
+}
+
+data class EitherSecond<T1, T2>(
+    override val t2: T2
+) : Either<T1, T2> {
+    override val t1: T1?
+        get() = null
+}
+
+inline fun <T1, T2> Either.Companion.first(t1: T1): Either<T1, T2> = EitherFirst(t1)
+inline fun <T1, T2> Either.Companion.second(t1: T1): Either<T1, T2> = EitherFirst(t1)
+
+inline fun <T1, T2, E : Either<T1, T2>> E.onFirst(crossinline block: (T1) -> Unit): E {
+    if (this is EitherFirst<*, *>) block(t1 as T1)
+    return this
+}
+
+inline fun <T1, T2, E : Either<T1, T2>> E.onSecond(crossinline block: (T2) -> Unit): E {
+    if (this is EitherSecond<*, *>) block(t2 as T2)
+    return this
+}