Add EmptyMessageChain and more extensions

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/contact/Contact.kt

@@ -5,8 +5,7 @@ package net.mamoe.mirai.contact
 import net.mamoe.mirai.Bot
 import net.mamoe.mirai.message.Message
 import net.mamoe.mirai.message.MessageChain
-import net.mamoe.mirai.message.PlainText
-import net.mamoe.mirai.message.toChain
+import net.mamoe.mirai.message.singleChain
 import net.mamoe.mirai.network.BotSession
 import net.mamoe.mirai.network.protocol.tim.handler.EventPacketHandler
 import net.mamoe.mirai.withSession
@@ -25,13 +24,11 @@ sealed class Contact(val bot: Bot, val id: UInt) {
 
     abstract suspend fun sendMessage(message: MessageChain)
 
-    abstract suspend fun sendXMLMessage(message: String)
 
+    //这两个方法应写为扩展函数, 但为方便 import 还是写在这里
+    suspend fun sendMessage(plain: String) = sendMessage(plain.singleChain())
 
-    //这两个方法写在 Contact 里面更适合. 因为 import 不便
-    suspend fun sendMessage(plain: String) = sendMessage(PlainText(plain))
-
-    suspend fun sendMessage(message: Message) = sendMessage(message.toChain())
+    suspend fun sendMessage(message: Message) = sendMessage(message.singleChain())
 }
 
 /**
@@ -75,14 +72,10 @@ class Group internal constructor(bot: Bot, val groupId: GroupId) : Contact(bot,
         bot.network[EventPacketHandler].sendGroupMessage(this, message)
     }
 
-    override suspend fun sendXMLMessage(message: String) {
-
-    }
-
     companion object
 }
 
-inline fun <R> Group.withSession(block: BotSession.() -> R): R = bot.withSession(block)
+inline fun <R> Contact.withSession(block: BotSession.() -> R): R = bot.withSession(block)
 
 /**
  * QQ 对象.
@@ -93,12 +86,17 @@ inline fun <R> Group.withSession(block: BotSession.() -> R): R = bot.withSession
  *
  * @author Him188moe
  */
-class QQ internal constructor(bot: Bot, id: UInt) : Contact(bot, id) {
+open class QQ internal constructor(bot: Bot, id: UInt) : Contact(bot, id) {
     override suspend fun sendMessage(message: MessageChain) {
         bot.network[EventPacketHandler].sendFriendMessage(this, message)
     }
+}
 
-    override suspend fun sendXMLMessage(message: String) {
-        TODO()
+/**
+ * 群成员
+ */
+class Member internal constructor(bot: Bot, id: UInt, val group: Group) : QQ(bot, id) {
+    init {
+        TODO("Group member implementation")
     }
 }

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/MessageSubscribers.kt

@@ -36,7 +36,7 @@ abstract class SenderAndMessage<TContact : Contact>(
      */
     suspend inline fun reply(message: MessageChain) = subject.sendMessage(message)
 
-    suspend fun reply(message: Message) = subject.sendMessage(message.toChain())
+    suspend fun reply(message: Message) = subject.sendMessage(message.singleChain())
     suspend fun reply(plain: String) = subject.sendMessage(plain.toMessage())
 
 

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/Message.kt

@@ -107,6 +107,7 @@ interface Message {
  * 将 [this] 发送给指定联系人
  */
 suspend inline fun Message.sendTo(contact: Contact) = contact.sendMessage(this)
+
 // endregion
 
 // region PlainText
@@ -118,6 +119,22 @@ inline class PlainText(override val stringValue: String) : Message {
 
     companion object Key : Message.Key<PlainText>
 }
+
+/**
+ * 构造 [PlainText]
+ */
+fun String.toMessage(): PlainText = PlainText(this)
+
+/**
+ * 得到包含作为 [PlainText] 的 [this] 的 [MessageChain].
+ *
+ * @return 唯一成员且不可修改的 [SingleMessageChainImpl]
+ *
+ * @see SingleMessageChain
+ * @see SingleMessageChainImpl
+ */
+fun String.singleChain(): MessageChain = this.toMessage().singleChain()
+
 // endregion
 
 // region Image
@@ -231,7 +248,26 @@ fun SingleMessageChain(delegate: Message): MessageChain {
 }
 // endregion
 
-// region extensions
+// region extensions for MessageChain
+
+/**
+ * 得到包含 [this] 的 [MessageChain].
+ * 若 [this] 为 [MessageChain] 将直接返回 this
+ * 否则将调用 [SingleMessageChain] 构造一个唯一成员且不可修改的 [SingleMessageChainImpl]
+ *
+ * @see SingleMessageChain
+ * @see SingleMessageChainImpl
+ */
+fun Message.singleChain(): MessageChain = if (this is MessageChain) this else SingleMessageChain(this)
+
+@Deprecated(message = "deprected", replaceWith = ReplaceWith("this.singleChain()"), level = DeprecationLevel.WARNING)
+fun Message.toChain(): MessageChain = singleChain()
+
+/**
+ * 构造 [MessageChain]
+ */
+fun List<Message>.toMessageChain(): MessageChain = MessageChain(this)
+
 
 /**
  * 获取第一个 [M] 类型的 [Message] 实例
@@ -249,6 +285,7 @@ inline fun <reified M : Message> MessageChain.first(): Message = this.first { M:
  */
 inline fun <reified M : Message> MessageChain.any(): Boolean = this.firstOrNull { M::class.isInstance(it) } !== null
 
+
 /**
  * 获取第一个 [M] 类型的 [Message] 实例
  */
@@ -299,7 +336,7 @@ interface MessageChain : Message, MutableList<Message> {
     }
 
     operator fun plusAssign(plain: String) {
-        this.concat(plain.toMessage())
+        this.plusAssign(plain.toMessage())
     }
 
     /**
@@ -311,6 +348,71 @@ interface MessageChain : Message, MutableList<Message> {
     operator fun <M : Message> get(key: Message.Key<M>): M = first(key)
 }
 
+/**
+ * 空的 [Message].
+ *
+ * 它不包含任何元素, 但维护一个 'lazy' 的 [delegate].
+ *
+ * 只有在必要的时候才会创建 list, 如迭代([iterator]), 插入([add]), 连接([concat], [plus], [plusAssign])时.
+ *
+ * 它是一个正常的 [Message] 和 [Message]. 可以做所有 [Message] 能做的事.
+ */
+class EmptyMessageChain : MessageChain {
+    private val delegate: MessageChainImpl by lazy { MessageChainImpl() }
+    private inline val initialized: Boolean get() = (::delegate as Lazy<*>).isInitialized()
+
+    override fun subList(fromIndex: Int, toIndex: Int): MutableList<Message> =
+        if (initialized) delegate.subList(
+            fromIndex,
+            toIndex
+        ) else throw IndexOutOfBoundsException("given args that from $fromIndex to $toIndex, but the list is empty")
+
+    override val stringValue: String
+        get() = if (initialized) delegate.stringValue else ""
+
+    override fun toString(): String = stringValue
+
+    override fun contains(sub: String): Boolean = if (initialized) delegate.contains(sub) else false
+    override fun contains(element: Message): Boolean = if (initialized) delegate.contains(element) else false
+    override fun concat(tail: Message): MessageChain = delegate.concat(tail)
+
+    override val size: Int = if (initialized) delegate.size else 0
+    override fun containsAll(elements: Collection<Message>): Boolean =
+        if (initialized) delegate.containsAll(elements) else false
+
+    override fun get(index: Int): Message =
+        if (initialized) delegate[index] else throw IndexOutOfBoundsException(index.toString())
+
+    override fun indexOf(element: Message): Int = if (initialized) delegate.indexOf(element) else -1
+    override fun isEmpty(): Boolean = if (initialized) delegate.isEmpty() else true
+    override fun iterator(): MutableIterator<Message> = delegate.iterator()
+
+    override fun lastIndexOf(element: Message): Int = if (initialized) delegate.lastIndexOf(element) else -1
+    override fun add(element: Message): Boolean = delegate.add(element)
+    override fun add(index: Int, element: Message) = delegate.add(index, element)
+    override fun addAll(index: Int, elements: Collection<Message>): Boolean = delegate.addAll(elements)
+    override fun addAll(elements: Collection<Message>): Boolean = delegate.addAll(elements)
+    override fun clear() {
+        if (initialized) delegate.clear()
+    }
+
+    override fun listIterator(): MutableListIterator<Message> = delegate.listIterator()
+
+    override fun listIterator(index: Int): MutableListIterator<Message> = delegate.listIterator()
+    override fun remove(element: Message): Boolean = if (initialized) delegate.remove(element) else false
+    override fun removeAll(elements: Collection<Message>): Boolean =
+        if (initialized) delegate.removeAll(elements) else false
+
+    override fun removeAt(index: Int): Message =
+        if (initialized) delegate.removeAt(index) else throw IndexOutOfBoundsException(index.toString())
+
+    override fun retainAll(elements: Collection<Message>): Boolean =
+        if (initialized) delegate.retainAll(elements) else false
+
+    override fun set(index: Int, element: Message): Message =
+        if (initialized) delegate.set(index, element) else throw IndexOutOfBoundsException(index.toString())
+}
+
 /**
  * Null 的 [MessageChain].
  * 它不包含任何元素, 也没有创建任何 list.
@@ -335,44 +437,56 @@ object NullMessageChain : MessageChain {
     override fun get(index: Int): Message = throw NoSuchElementException()
     override fun indexOf(element: Message): Int = -1
     override fun isEmpty(): Boolean = true
-    override fun iterator(): MutableIterator<Message> = object : MutableIterator<Message> {
-        override fun hasNext(): Boolean = false
-        override fun next(): Message = throw NoSuchElementException()
-        override fun remove() = throw NoSuchElementException()
-    }
+    override fun iterator(): MutableIterator<Message> = EmptyMutableIterator()
 
     override fun lastIndexOf(element: Message): Int = -1
     override fun add(element: Message): Boolean = unsupported()
-    override fun add(index: Int, element: Message) = unsupported()
-    override fun addAll(index: Int, elements: Collection<Message>): Boolean = unsupported()
+    override fun add(index: Int, element: Message) = throw IndexOutOfBoundsException(index.toString())
+    override fun addAll(index: Int, elements: Collection<Message>): Boolean =
+        throw IndexOutOfBoundsException(index.toString())
+
     override fun addAll(elements: Collection<Message>): Boolean = unsupported()
     override fun clear() {}
-    override fun listIterator(): MutableListIterator<Message> = object : MutableListIterator<Message> {
-        override fun hasPrevious(): Boolean = false
-        override fun nextIndex(): Int = -1
-        override fun previous(): Message = throw NoSuchElementException()
-        override fun previousIndex(): Int = -1
-        override fun add(element: Message) = unsupported()
-        override fun hasNext(): Boolean = false
-        override fun next(): Message = throw NoSuchElementException()
-        override fun remove() = throw NoSuchElementException()
-        override fun set(element: Message) = unsupported()
-    }
+    override fun listIterator(): MutableListIterator<Message> = EmptyMutableListIterator()
+
+    override fun listIterator(index: Int): MutableListIterator<Message> =
+        throw IndexOutOfBoundsException(index.toString())
 
-    override fun listIterator(index: Int): MutableListIterator<Message> = unsupported()
     override fun remove(element: Message): Boolean = false
     override fun removeAll(elements: Collection<Message>): Boolean = false
-    override fun removeAt(index: Int): Message = throw NoSuchElementException()
+    override fun removeAt(index: Int): Message = throw IndexOutOfBoundsException(index.toString())
     override fun retainAll(elements: Collection<Message>): Boolean = false
-    override fun set(index: Int, element: Message): Message = unsupported()
+    override fun set(index: Int, element: Message): Message = throw IndexOutOfBoundsException(index.toString())
     private fun unsupported(): Nothing = throw UnsupportedOperationException()
 }
 
+// endregion
+
+// region internal
 
 // ==============================================================================
 // ================================== INTERNAL ==================================
 // ==============================================================================
 
+@Suppress("FunctionName")
+private fun <E> EmptyMutableIterator(): MutableIterator<E> = object : MutableIterator<E> {
+    override fun hasNext(): Boolean = false
+    override fun next(): E = throw NoSuchElementException()
+    override fun remove() = throw NoSuchElementException()
+}
+
+@Suppress("FunctionName")
+private fun <E> EmptyMutableListIterator(): MutableListIterator<E> = object : MutableListIterator<E> {
+    override fun hasPrevious(): Boolean = false
+    override fun nextIndex(): Int = -1
+    override fun previous(): E = throw NoSuchElementException()
+    override fun previousIndex(): Int = -1
+    override fun add(element: E) = throw UnsupportedOperationException()
+    override fun hasNext(): Boolean = false
+    override fun next(): E = throw NoSuchElementException()
+    override fun remove() = throw NoSuchElementException()
+    override fun set(element: E) = throw UnsupportedOperationException()
+}
 
 /**
  * [MessageChain] 实现
@@ -431,7 +545,8 @@ internal inline class MessageChainImpl constructor(
 
 /**
  * 单个成员的不可修改的 [MessageChain].
- * 在连接时将会把它当做一个普通 [Message] 看待.
+ *
+ * 在连接时将会把它当做一个普通 [Message] 看待, 但它不能被 [plusAssign]
  */
 internal inline class SingleMessageChainImpl(
     private val delegate: Message
@@ -441,14 +556,16 @@ internal inline class SingleMessageChainImpl(
     override val stringValue: String get() = this.delegate.stringValue
 
     override operator fun contains(sub: String): Boolean = delegate.contains(sub)
-    override fun concat(tail: Message): MessageChain {
-        if (tail is MessageChain) tail.forEach { child -> this.concat(child) }
+    override fun concat(tail: Message): MessageChain =
+        if (tail is MessageChain) tail.apply { concat(delegate) }
         else MessageChain(delegate, tail)
-        return this
-    }
+
+    override fun plusAssign(message: Message) =
+        throw UnsupportedOperationException("SingleMessageChainImpl cannot be plusAssigned")
 
     override fun toString(): String = stringValue
     // endregion
+
     // region MutableList override
     override fun containsAll(elements: Collection<Message>): Boolean = elements.all { it === delegate }
 
@@ -484,7 +601,9 @@ internal inline class SingleMessageChainImpl(
         override fun set(element: Message) = throw UnsupportedOperationException()
     }
 
-    override fun listIterator(index: Int): MutableListIterator<Message> = if (index == 0) listIterator() else throw UnsupportedOperationException()
+    override fun listIterator(index: Int): MutableListIterator<Message> =
+        if (index == 0) listIterator() else throw UnsupportedOperationException()
+
     override fun remove(element: Message): Boolean = throw UnsupportedOperationException()
     override fun removeAll(elements: Collection<Message>): Boolean = throw UnsupportedOperationException()
     override fun removeAt(index: Int): Message = throw UnsupportedOperationException()
@@ -514,4 +633,5 @@ internal inline class SingleMessageChainImpl(
     override operator fun contains(element: Message): Boolean = element === delegate
     override val size: Int get() = 1
     // endregion
-}
+}
+// endregion

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/Messages.kt

@@ -1,28 +0,0 @@
-package net.mamoe.mirai.message
-
-// Message 扩展方法
-/**
- * 构造 [PlainText]
- */
-fun String.toMessage(): PlainText = PlainText(this)
-
-/**
- * 得到包含 [this] 的 [MessageChain].
- * 若 [this] 为 [MessageChain] 将直接返回 this
- * 否则将调用 [SingleMessageChain] 构造一个唯一成员不可修改的 [SingleMessageChainImpl]
- *
- * @see SingleMessageChain
- * @see SingleMessageChainImpl
- */
-fun Message.toChain(): MessageChain = if (this is MessageChain) this else SingleMessageChain(this)
-
-/**
- * 以 [this] 为代表 (delegate) 构造 [SingleMessageChain].
- * @throws IllegalArgumentException 当 [this] 为 [MessageChain] 的实例时
- */
-fun Message.singleChain(): MessageChain = SingleMessageChain(this)
-
-/**
- * 构造 [MessageChain]
- */
-fun List<Message>.toMessageChain(): MessageChain = MessageChain(this)

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/network/protocol/tim/packet/event/ServerEventPackets.kt

@@ -124,6 +124,7 @@ class IgnoredServerEventPacket(input: ByteReadPacket, eventIdentity: EventPacket
  * Unknown event
  */
 class UnknownServerEventPacket(
+    @Suppress("MemberVisibilityCanBePrivate")
     val eventId: ByteArray,
     private val showData: Boolean = false,
     input: ByteReadPacket,