1 files changed, 76 insertions, 0 deletions
diff --git a/runtime/commonMain/src/kotlinx/serialization/internal/Enums.kt b/runtime/commonMain/src/kotlinx/serialization/internal/Enums.kt
new file mode 100644
index 00000000..87fdc9e3
--- /dev/null
+++ b/runtime/commonMain/src/kotlinx/serialization/internal/Enums.kt
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2018 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlinx.serialization.internal
+
+import kotlinx.serialization.*
+import kotlin.reflect.KClass
+
+public class EnumDescriptor(override val name: String, private val choices: Array<String>) : SerialClassDescImpl(name) {
+    override val kind: SerialKind = UnionKind.ENUM_KIND
+
+    init {
+        choices.forEach { addElement(it) }
+    }
+
+    override fun getElementDescriptor(index: Int): SerialDescriptor {
+        return this
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other == null || this::class != other::class) return false
+
+        other as EnumDescriptor
+
+        if (name != other.name) return false
+        if (!choices.contentEquals(other.choices)) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = super.hashCode()
+        result = 31 * result + name.hashCode()
+        result = 31 * result + choices.contentHashCode()
+        return result
+    }
+}
+
+open class CommonEnumSerializer<T>(val serialName: String, val choices: Array<T>, choicesNames: Array<String>) :
+    KSerializer<T> {
+    override val descriptor: EnumDescriptor = EnumDescriptor(serialName, choicesNames)
+
+    final override fun serialize(encoder: Encoder, obj: T) {
+        val index = choices.indexOf(obj)
+            .also { check(it != -1) { "$obj is not a valid enum $serialName, choices are $choices" } }
+        encoder.encodeEnum(descriptor, index)
+    }
+
+    final override fun deserialize(decoder: Decoder): T {
+        val index = decoder.decodeEnum(descriptor)
+        check(index in choices.indices)
+            { "$index is not among valid $serialName choices, choices size is ${choices.size}" }
+        return choices[index]
+    }
+}
+
+// Binary backwards-compatible with plugin
+class EnumSerializer<T : Enum<T>>(serializableClass: KClass<T>) : CommonEnumSerializer<T>(
+    serializableClass.enumClassName(),
+    serializableClass.enumMembers(),
+    serializableClass.enumMembers().map { it.name }.toTypedArray()
+)