API stabilization:

Extract ExtensionPoint;
Rename ExtensionPoint.extensionType;
Declare ExtensionPoint stable;
Improve ExtensionException

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/extension/ComponentStorage.kt

@@ -154,7 +154,7 @@ internal abstract class AbstractConcurrentComponentStorage : ComponentStorage {
         throwable: Throwable,
     ) {
         throw ExtensionException(
-            "Exception while executing extension ${extension.kClassQualifiedNameOrTip} provided by plugin '${plugin.name}', registered for ${this.type.qualifiedName}",
+            "Exception while executing extension '${extension.kClassQualifiedNameOrTip}' provided by plugin '${plugin.name}', registered for '${this.extensionType.qualifiedName}'",
             throwable
         )
     }

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/extension/ExtensionException.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020 Mamoe Technologies and contributors.
+ *
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ * https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+@file:Suppress("unused")
+
+package net.mamoe.mirai.console.extension
+
+/**
+ * 在调用一个 extension 时遇到的异常.
+ */
+public open class ExtensionException : RuntimeException {
+    public constructor() : super()
+    public constructor(message: String?) : super(message)
+    public constructor(message: String?, cause: Throwable?) : super(message, cause)
+    public constructor(cause: Throwable?) : super(cause)
+}

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/extension/ExtensionPoint.kt

@@ -11,52 +11,20 @@
 
 package net.mamoe.mirai.console.extension
 
-import net.mamoe.mirai.console.plugin.loader.PluginLoader
-import net.mamoe.mirai.console.util.ConsoleExperimentalApi
 import kotlin.reflect.KClass
-import kotlin.reflect.full.isSubclassOf
 
-@ConsoleExperimentalApi
+/**
+ * 由 [Extension] 的 `companion` 实现.
+ */
 public interface ExtensionPoint<T : Extension> {
-    public val type: KClass<T>
+    public val extensionType: KClass<T>
-
-    public companion object {
-        @JvmStatic
-        @JvmSynthetic
-        @ConsoleExperimentalApi
-        public inline fun <reified T : Extension> ExtensionPoint<*>.isFor(exactType: Boolean = false): Boolean {
-            return if (exactType) {
-                T::class == type
-            } else T::class.isSubclassOf(type)
-        }
-    }
 }
 
-@ConsoleExperimentalApi
-public interface SingletonExtensionPoint<T : SingletonExtension<*>> : ExtensionPoint<T>
-
-/**
- * 表示一个扩展点
- */
-@ConsoleExperimentalApi
 public open class AbstractExtensionPoint<T : Extension>(
-    @ConsoleExperimentalApi
+    public override val extensionType: KClass<T>,
-    public override val type: KClass<T>,
 ) : ExtensionPoint<T>
 
-
 /**
- * 在调用一个 extension 时遇到的异常.
+ * 表示一个 [SingletonExtension] 的 [ExtensionPoint]
- *
- * @see PluginLoader.load
- * @see PluginLoader.enable
- * @see PluginLoader.disable
- * @see PluginLoader.description
  */
-@ConsoleExperimentalApi
+public interface SingletonExtensionPoint<T : SingletonExtension<*>> : ExtensionPoint<T>
-public open class ExtensionException : RuntimeException {
-    public constructor() : super()
-    public constructor(message: String?) : super(message)
-    public constructor(message: String?, cause: Throwable?) : super(message, cause)
-    public constructor(cause: Throwable?) : super(cause)
-}