Fixes recover inconsistency with raise DSL on types other than Either

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

@@ -3283,9 +3283,12 @@ public final class arrow/core/raise/IorRaise : arrow/core/raise/Raise {
 	public final fun bindAllIor (Ljava/util/Map;)Ljava/util/Map;
 	public final fun bindAllIor (Ljava/util/Set;)Ljava/util/Set;
 	public fun catch (Larrow/core/continuations/Effect;Lkotlin/jvm/functions/Function3;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public final fun combine (Ljava/lang/Object;)Ljava/lang/Object;
+	public final fun getCombineError ()Lkotlin/jvm/functions/Function2;
 	public fun invoke (Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun raise (Ljava/lang/Object;)Ljava/lang/Void;
+	public final fun recover (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public fun shift (Ljava/lang/Object;)Ljava/lang/Object;
 }
 
@@ -3313,6 +3316,7 @@ public final class arrow/core/raise/NullableRaise : arrow/core/raise/Raise {
 	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public synthetic fun raise (Ljava/lang/Object;)Ljava/lang/Void;
 	public fun raise (Ljava/lang/Void;)Ljava/lang/Void;
+	public final fun recover (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function0;)Ljava/lang/Object;
 	public synthetic fun shift (Ljava/lang/Object;)Ljava/lang/Object;
 	public fun shift (Ljava/lang/Void;)Ljava/lang/Object;
 }
@@ -3342,6 +3346,7 @@ public final class arrow/core/raise/OptionRaise : arrow/core/raise/Raise {
 	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun raise (Larrow/core/None;)Ljava/lang/Void;
 	public synthetic fun raise (Ljava/lang/Object;)Ljava/lang/Void;
+	public final fun recover (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function0;)Ljava/lang/Object;
 	public fun shift (Larrow/core/None;)Ljava/lang/Object;
 	public synthetic fun shift (Ljava/lang/Object;)Ljava/lang/Object;
 }
@@ -3506,6 +3511,7 @@ public final class arrow/core/raise/ResultRaise : arrow/core/raise/Raise {
 	public fun invoke (Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public synthetic fun raise (Ljava/lang/Object;)Ljava/lang/Void;
 	public fun raise (Ljava/lang/Throwable;)Ljava/lang/Void;
+	public final fun recover (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Ljava/lang/Object;
 	public synthetic fun shift (Ljava/lang/Object;)Ljava/lang/Object;
 	public fun shift (Ljava/lang/Throwable;)Ljava/lang/Object;
 }

arrow-libs/core/arrow-core/src/commonMain/kotlin/arrow/core/raise/Builders.kt

@@ -7,6 +7,7 @@ package arrow.core.raise
 import arrow.atomic.Atomic
 import arrow.atomic.updateAndGet
 import arrow.core.Either
+import arrow.core.EmptyValue.combine
 import arrow.core.Ior
 import arrow.core.NonEmptyList
 import arrow.core.NonEmptySet
@@ -72,6 +73,15 @@ public class NullableRaise(private val raise: Raise<Null>) : Raise<Null> by rais
     contract { returns() implies (value != null) }
     return ensureNotNull(value) { null }
   }
+
+  @RaiseDSL
+  public inline fun <A> recover(
+    @BuilderInference block: NullableRaise.() -> A,
+    recover: () -> A,
+  ): A = when (val nullable = nullable(block)) {
+    null -> recover()
+    else -> nullable
+  }
 }
 
 public class ResultRaise(private val raise: Raise<Throwable>) : Raise<Throwable> by raise {
@@ -96,6 +106,15 @@ public class ResultRaise(private val raise: Raise<Throwable>) : Raise<Throwable>
   @JvmName("bindAllResult")
   public fun <A> NonEmptySet<Result<A>>.bindAll(): NonEmptySet<A> =
     map { it.bind() }
+
+  @RaiseDSL
+  public inline fun <A> recover(
+    @BuilderInference block: ResultRaise.() -> A,
+    recover: (Throwable) -> A,
+  ): A = result(block).fold(
+    onSuccess = { it },
+    onFailure =  { recover(it) }
+  )
 }
 
 public class OptionRaise(private val raise: Raise<None>) : Raise<None> by raise {
@@ -129,10 +148,19 @@ public class OptionRaise(private val raise: Raise<None>) : Raise<None> by raise
     contract { returns() implies (value != null) }
     return ensureNotNull(value) { None }
   }
+
+  @RaiseDSL
+  public inline fun <A> recover(
+    @BuilderInference block: OptionRaise.() -> A,
+    recover: () -> A,
+  ): A = when (val option = option(block)) {
+    is None -> recover()
+    is Some<A> -> option.value
+  }
 }
 
 public class IorRaise<Error> @PublishedApi internal constructor(
-  private val combineError: (Error, Error) -> Error,
+  @PublishedApi internal val combineError: (Error, Error) -> Error,
   private val state: Atomic<Option<Error>>,
   private val raise: Raise<Error>,
 ) : Raise<Error> {
@@ -170,8 +198,23 @@ public class IorRaise<Error> @PublishedApi internal constructor(
   public fun <K, V> Map<K, Ior<Error, V>>.bindAll(): Map<K, V> =
     mapValues { (_, v) -> v.bind() }
 
-  private fun combine(other: Error): Error =
+  @PublishedApi
+  internal fun combine(other: Error): Error =
     state.updateAndGet { prev ->
       Some(prev.map { combineError(it, other) }.getOrElse { other })
     }.getOrElse { other }
+
+  @RaiseDSL
+  public inline fun <A> recover(
+    @BuilderInference block: IorRaise<Error>.() -> A,
+    recover: (error: Error) -> A,
+  ): A = when (val ior = ior(combineError, block)) {
+    is Ior.Both -> {
+      combine(ior.leftValue)
+      ior.rightValue
+    }
+
+    is Ior.Left -> recover(ior.value)
+    is Ior.Right -> ior.value
+  }
 }

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/raise/IorSpec.kt

@@ -3,15 +3,11 @@ package arrow.core.raise
 import arrow.core.Either
 import arrow.core.Ior
 import arrow.core.test.nonEmptyList
-import arrow.typeclasses.Semigroup
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.core.spec.style.StringSpec
 import io.kotest.matchers.shouldBe
 import io.kotest.property.Arb
-import io.kotest.property.arbitrary.filter
 import io.kotest.property.arbitrary.int
-import io.kotest.property.arbitrary.list
-import io.kotest.property.arbitrary.string
 import io.kotest.property.checkAll
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
@@ -79,4 +75,13 @@ class IorSpec : StringSpec({
       }
     }.message shouldBe "Boom!"
   }
+
+  "Recover works as expected" {
+    ior(String::plus) {
+      val one = recover({ Ior.Left("Hello").bind() }) { 1 }
+      val two = Ior.Right(2).bind()
+      val three = Ior.Both(", World", 3).bind()
+      one + two + three
+    } shouldBe Ior.Both(", World", 6)
+  }
 })

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/raise/NullableSpec.kt

@@ -118,4 +118,12 @@ class NullableSpec : StringSpec({
       either.bind() + 3
     } shouldBe 7
   }
+
+  "Recover works as expected" {
+    nullable {
+      val one: Int = recover({ null.bind<Int>() }) { 1 }
+      val two = 2.bind()
+      one + two
+    } shouldBe 3
+  }
 })

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/raise/OptionSpec.kt

@@ -1,6 +1,7 @@
 package arrow.core.raise
 
 import arrow.core.None
+import arrow.core.Some
 import arrow.core.some
 import arrow.core.toOption
 import io.kotest.core.spec.style.StringSpec
@@ -39,4 +40,12 @@ class OptionSpec : StringSpec({
       throw IllegalStateException("This should not be executed")
     } shouldBe None
   }
+
+  "Recover works as expected" {
+    option {
+      val one: Int = recover({ None.bind<Int>() }) { 1 }
+      val two = Some(2).bind()
+      one + two
+    } shouldBe Some(3)
+  }
 })

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/raise/ResultSpec.kt

@@ -20,4 +20,12 @@ class ResultSpec : StringSpec({
   "Result - raise" {
     result { raise(boom) } shouldBe Result.failure(boom)
   }
+
+  "Recover works as expected" {
+    result {
+      val one: Int = recover({ Result.failure<Int>(boom).bind() }) { 1 }
+      val two = Result.success(2).bind()
+      one + two
+    } shouldBe Result.success(3)
+  }
 })