max and min methods for NonEmptyList

arrow-libs/core/arrow-core/api/arrow-core.api

@@ -743,6 +743,10 @@ public final class arrow/core/NonEmptyList$Companion {
 public final class arrow/core/NonEmptyListKt {
 	public static final fun compareTo (Larrow/core/NonEmptyList;Larrow/core/NonEmptyList;)I
 	public static final fun flatten (Larrow/core/NonEmptyList;)Larrow/core/NonEmptyList;
+	public static final fun max (Larrow/core/NonEmptyList;)Ljava/lang/Comparable;
+	public static final fun maxBy (Larrow/core/NonEmptyList;Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
+	public static final fun min (Larrow/core/NonEmptyList;)Ljava/lang/Comparable;
+	public static final fun minBy (Larrow/core/NonEmptyList;Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public static final fun nel (Ljava/lang/Object;)Larrow/core/NonEmptyList;
 	public static final fun nonEmptyListOf (Ljava/lang/Object;[Ljava/lang/Object;)Larrow/core/NonEmptyList;
 	public static final fun sequence (Larrow/core/NonEmptyList;)Larrow/core/Either;

arrow-libs/core/arrow-core/src/commonMain/kotlin/arrow/core/NonEmptyList.kt

@@ -396,6 +396,18 @@ public operator fun <A : Comparable<A>> NonEmptyList<A>.compareTo(other: NonEmpt
 public fun <A> NonEmptyList<NonEmptyList<A>>.flatten(): NonEmptyList<A> =
   this.flatMap(::identity)
 
+public inline fun <A, B : Comparable<B>> NonEmptyList<A>.minBy(selector: (A) -> B): A =
+  minByOrNull(selector)!!
+
+public inline fun <A, B : Comparable<B>> NonEmptyList<A>.maxBy(selector: (A) -> B): A =
+  maxByOrNull(selector)!!
+
+public inline fun <T : Comparable<T>> NonEmptyList<T>.min(): T =
+  minOrNull()!!
+
+public inline fun <T : Comparable<T>> NonEmptyList<T>.max(): T =
+  maxOrNull()!!
+
 public fun <A, B> NonEmptyList<Pair<A, B>>.unzip(): Pair<NonEmptyList<A>, NonEmptyList<B>> =
   this.unzip(::identity)
 

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/NonEmptyListTest.kt

@@ -267,5 +267,46 @@ class NonEmptyListTest : UnitSpec() {
         result shouldBe expected
       }
     }
+
+    "max element" {
+      checkAll(
+        Arb.nonEmptyList(Arb.int())
+      ) { a ->
+        val result = a.max()
+        val expected = a.maxOrNull()
+        result shouldBe expected
+      }
+    }
+
+    "maxBy element" {
+      checkAll(
+        Arb.nonEmptyList(Arb.int())
+      ) { a ->
+        val result = a.maxBy(::identity)
+        val expected = a.maxByOrNull(::identity)
+        result shouldBe expected
+      }
+    }
+
+    "min element" {
+      checkAll(
+        Arb.nonEmptyList(Arb.int())
+      ) { a ->
+        val result = a.min()
+        val expected = a.minOrNull()
+        result shouldBe expected
+      }
+    }
+
+
+    "minBy element" {
+      checkAll(
+        Arb.nonEmptyList(Arb.int())
+      ) { a ->
+        val result = a.minBy(::identity)
+        val expected = a.minByOrNull(::identity)
+        result shouldBe expected
+      }
+    }
   }
 }