Rename valueReified to value;

Introduce public valueFromKType;
Fix CompositeListValueImpl

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/setting/Setting.kt

@@ -14,17 +14,16 @@ package net.mamoe.mirai.console.setting
 import kotlinx.serialization.*
 import kotlinx.serialization.builtins.MapSerializer
 import kotlinx.serialization.builtins.serializer
-import net.mamoe.mirai.console.setting.internal.cast
 import net.mamoe.mirai.console.setting.internal.isOdd
+import net.mamoe.mirai.console.setting.internal.typeOf0
 import net.mamoe.mirai.console.setting.internal.valueFromKTypeImpl
 import net.mamoe.mirai.console.setting.internal.valueImpl
-import net.mamoe.mirai.utils.MiraiExperimentalAPI
 import net.mamoe.yamlkt.YamlNullableDynamicSerializer
 import kotlin.internal.LowPriorityInOverloadResolution
 import kotlin.reflect.KProperty
 import kotlin.reflect.KType
 import kotlin.reflect.full.findAnnotation
-import kotlin.reflect.typeOf
+import kotlin.reflect.jvm.isAccessible
 
 
 // TODO: 2020/6/21 move to JvmPlugin to inherit SettingStorage and CoroutineScope for saving
@@ -162,7 +161,21 @@ fun Setting.value(default: String): SerializerAwareValue<String> = valueImpl(def
 
 
 /**
- * Creates a [Value] with reified type.
+ * Creates a [Value] with reified type, and set default value.
+ *
+ * @param T reified param type T.
+ * Supports only primitives, Kotlin built-in collections,
+ * and classes that are serializable with Kotlinx.serialization
+ * (typically annotated with [kotlinx.serialization.Serializable])
+ */
+@Suppress("UNCHECKED_CAST")
+@LowPriorityInOverloadResolution
+inline fun <reified T> Setting.value(default: T): SerializerAwareValue<T> =
+    value<T>().apply { value = default }
+
+
+/**
+ * Creates a [Value] with reified type, and set default value by reflection to its no-arg public constructor.
  *
  * @param T reified param type T.
  * Supports only primitives, Kotlin built-in collections,
@@ -170,12 +183,17 @@ fun Setting.value(default: String): SerializerAwareValue<String> = valueImpl(def
  * (typically annotated with [kotlinx.serialization.Serializable])
  */
 @LowPriorityInOverloadResolution
-@MiraiExperimentalAPI
-@OptIn(ExperimentalStdlibApi::class) // stable in 1.4
-inline fun <reified T> Setting.valueReified(default: T): SerializerAwareValue<T> =
-    valueFromKTypeImpl(typeOf<T>()).cast()
+inline fun <reified T> Setting.value(): SerializerAwareValue<T> =
+    value(
+        T::class.constructors.find { it.parameters.isEmpty() && it.isAccessible }?.call()
+            ?: throw IllegalArgumentException("Cannot construct a default value for given type ${typeOf0<T>()}")
+    )
 
-@MiraiExperimentalAPI
-fun <T> Setting.valueFromKType(type: KType): SerializerAwareValue<T> = valueFromKTypeImpl(type).cast()
+/**
+ * Creates a [Value] with specified [KType], and set default value.
+ */
+@Suppress("UNCHECKED_CAST")
+fun <T> Setting.valueFromKType(type: KType, default: T): SerializerAwareValue<T> =
+    (valueFromKTypeImpl(type) as SerializerAwareValue<Any?>).apply { this.value = default } as SerializerAwareValue<T>
 
 // TODO: 2020/6/24 Introduce class TypeToken for compound types for Java.

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/setting/internal/Setting.value composite impl.kt

@@ -26,6 +26,10 @@ private val primitiveCollectionsImplemented by lazy {
     false
 }
 
+@PublishedApi
+@OptIn(ExperimentalStdlibApi::class)
+internal inline fun <reified T> typeOf0(): KType = kotlin.reflect.typeOf<T>()
+
 @PublishedApi
 @Suppress("UnsafeCall", "SMARTCAST_IMPOSSIBLE", "UNCHECKED_CAST")
 internal fun Setting.valueFromKTypeImpl(type: KType): SerializerAwareValue<*> {
@@ -54,8 +58,8 @@ internal fun Setting.valueFromKTypeImpl(type: KType): SerializerAwareValue<*> {
                 TODO()
             } else {
                 return createCompositeMapValueImpl<Any?, Any?>(
-                    kToValue = { k -> valueFromKType<Any?>(type.arguments[0].type!!).also { it.value = k } },
-                    vToValue = { v -> valueFromKType<Any?>(type.arguments[1].type!!).also { it.value = v } }
+                    kToValue = { k -> valueFromKType(type.arguments[0].type!!, k) },
+                    vToValue = { v -> valueFromKType(type.arguments[1].type!!, v) }
                 ).serializableValueWith(serializerMirai(type) as KSerializer<Map<Any?, Any?>>) // erased
             }
         }
@@ -72,7 +76,7 @@ internal fun Setting.valueFromKTypeImpl(type: KType): SerializerAwareValue<*> {
                 // ...
                 TODO()
             } else {
-                return createCompositeListValueImpl<Any?> { valueFromKType(type.arguments[0].type!!) }
+                return createCompositeListValueImpl<Any?> { v -> valueFromKType(type.arguments[0].type!!, v) }
                     .serializableValueWith(serializerMirai(type) as KSerializer<List<Any?>>)
             }
         }
@@ -87,7 +91,7 @@ internal fun Setting.valueFromKTypeImpl(type: KType): SerializerAwareValue<*> {
                 // ...
                 TODO()
             } else {
-                return createCompositeSetValueImpl<Any?> { valueFromKType(type.arguments[0].type!!) }
+                return createCompositeSetValueImpl<Any?> { v -> valueFromKType(type.arguments[0].type!!, v) }
                     .serializableValueWith(serializerMirai(type) as KSerializer<Set<Any?>>)
             }
         }

backend/mirai-console/src/test/kotlin/net/mamoe/mirai/console/setting/SettingTest.kt

@@ -20,8 +20,8 @@ internal class SettingTest {
 
     class MySetting : Setting() {
         var int by value(1)
-        val map by valueReified(mapOf("" to ""))
-        val map2 by valueReified(mutableMapOf("" to mutableMapOf("" to "")))
+        val map by value(mapOf("" to ""))
+        val map2 by value(mutableMapOf("" to mutableMapOf("" to "")))
     }
 
     @OptIn(UnstableDefault::class)