Review CommandArgumentContext and command

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/BuiltInCommands.kt

@@ -15,7 +15,11 @@ import kotlinx.coroutines.sync.withLock
 import net.mamoe.mirai.alsoLogin
 import net.mamoe.mirai.console.MiraiConsole
 import net.mamoe.mirai.console.command.CommandManager.INSTANCE.register
-import net.mamoe.mirai.console.command.descriptor.*
+import net.mamoe.mirai.console.command.descriptor.CommandArgumentParserException
+import net.mamoe.mirai.console.command.descriptor.CommandValueArgumentParser.Companion.map
+import net.mamoe.mirai.console.command.descriptor.PermissionIdValueArgumentParser
+import net.mamoe.mirai.console.command.descriptor.PermitteeIdValueArgumentParser
+import net.mamoe.mirai.console.command.descriptor.buildCommandArgumentContext
 import net.mamoe.mirai.console.internal.command.CommandManagerImpl
 import net.mamoe.mirai.console.internal.command.CommandManagerImpl.allRegisteredCommands
 import net.mamoe.mirai.console.internal.util.runIgnoreException
@@ -154,7 +158,7 @@ public object BuiltInCommands {
             Permission::class with PermissionIdValueArgumentParser.map { id ->
                 kotlin.runCatching {
                     id.findCorrespondingPermissionOrFail()
-                }.getOrElse { illegalArgument("指令不存在: $id", it) }
+                }.getOrElse { throw CommandArgumentParserException("指令不存在: $id", it) }
             }
         },
     ), BuiltInCommandInternal {

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/Command.kt

@@ -14,7 +14,6 @@ package net.mamoe.mirai.console.command
 import net.mamoe.mirai.console.command.descriptor.CommandArgumentContextAware
 import net.mamoe.mirai.console.command.descriptor.CommandSignatureVariant
 import net.mamoe.mirai.console.command.descriptor.ExperimentalCommandDescriptors
-import net.mamoe.mirai.console.command.java.JCommand
 import net.mamoe.mirai.console.compiler.common.ResolveContext
 import net.mamoe.mirai.console.compiler.common.ResolveContext.Kind.COMMAND_NAME
 import net.mamoe.mirai.console.permission.Permission
@@ -31,8 +30,6 @@ import net.mamoe.mirai.console.util.ConsoleExperimentalApi
  * @see SimpleCommand 简单的, 支持参数自动解析的指令
  *
  * @see CommandArgumentContextAware
- *
- * @see JCommand 为 Java 用户添加协程帮助的 [Command]
  */
 public interface Command {
     /**

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/descriptor/CommandArgumentContext.kt

@@ -23,6 +23,8 @@ import net.mamoe.mirai.contact.*
 import net.mamoe.mirai.message.data.Image
 import net.mamoe.mirai.message.data.MessageContent
 import net.mamoe.mirai.message.data.PlainText
+import kotlin.contracts.InvocationKind.EXACTLY_ONCE
+import kotlin.contracts.contract
 import kotlin.internal.LowPriorityInOverloadResolution
 import kotlin.reflect.KClass
 import kotlin.reflect.full.isSubclassOf
@@ -49,9 +51,17 @@ public interface CommandArgumentContext {
     public data class ParserPair<T : Any>(
         val klass: KClass<T>,
         val parser: CommandValueArgumentParser<T>,
-    )
+    ) {
+        public companion object {
+            @JvmStatic
+            public fun <T : Any> ParserPair<T>.toPair(): Pair<KClass<T>, CommandValueArgumentParser<T>> = klass to parser
+        }
+    }
 
-    public operator fun <T : Any> get(klass: KClass<out T>): CommandValueArgumentParser<T>?
+    /**
+     * 获取一个 [kClass] 类型的解析器.
+     */
+    public operator fun <T : Any> get(kClass: KClass<T>): CommandValueArgumentParser<T>?
 
     public fun toList(): List<ParserPair<*>>
 
@@ -59,7 +69,7 @@ public interface CommandArgumentContext {
         /**
          * For Java callers.
          *
-         * @see [EmptyCommandArgumentContext]
+         * @see EmptyCommandArgumentContext
          */
         @JvmStatic
         public val EMPTY: CommandArgumentContext = EmptyCommandArgumentContext
@@ -108,6 +118,9 @@ public interface CommandArgumentContextAware {
     public val context: CommandArgumentContext
 }
 
+/**
+ * @see CommandArgumentContext.EMPTY
+ */
 public object EmptyCommandArgumentContext : CommandArgumentContext by SimpleCommandArgumentContext(listOf())
 
 /**
@@ -117,8 +130,8 @@ public operator fun CommandArgumentContext.plus(replacer: CommandArgumentContext
     if (replacer == EmptyCommandArgumentContext) return this
     if (this == EmptyCommandArgumentContext) return replacer
     return object : CommandArgumentContext {
-        override fun <T : Any> get(klass: KClass<out T>): CommandValueArgumentParser<T>? =
-            replacer[klass] ?: this@plus[klass]
+        override fun <T : Any> get(kClass: KClass<T>): CommandValueArgumentParser<T>? =
+            replacer[kClass] ?: this@plus[kClass]
 
         override fun toList(): List<ParserPair<*>> = replacer.toList() + this@plus.toList()
     }
@@ -132,9 +145,9 @@ public operator fun CommandArgumentContext.plus(replacer: List<ParserPair<*>>):
     if (this == EmptyCommandArgumentContext) return SimpleCommandArgumentContext(replacer)
     return object : CommandArgumentContext {
         @Suppress("UNCHECKED_CAST")
-        override fun <T : Any> get(klass: KClass<out T>): CommandValueArgumentParser<T>? =
-            replacer.firstOrNull { klass.isSubclassOf(it.klass) }?.parser as CommandValueArgumentParser<T>?
-                ?: this@plus[klass]
+        override fun <T : Any> get(kClass: KClass<T>): CommandValueArgumentParser<T>? =
+            replacer.firstOrNull { kClass.isSubclassOf(it.klass) }?.parser as CommandValueArgumentParser<T>?
+                ?: this@plus[kClass]
 
         override fun toList(): List<ParserPair<*>> = replacer.toList() + this@plus.toList()
     }
@@ -149,9 +162,9 @@ public operator fun CommandArgumentContext.plus(replacer: List<ParserPair<*>>):
 public class SimpleCommandArgumentContext(
     public val list: List<ParserPair<*>>,
 ) : CommandArgumentContext {
-    override fun <T : Any> get(klass: KClass<out T>): CommandValueArgumentParser<T>? =
-        (this.list.firstOrNull { klass == it.klass }?.parser
-            ?: this.list.firstOrNull { klass.isSubclassOf(it.klass) }?.parser) as CommandValueArgumentParser<T>?
+    override fun <T : Any> get(kClass: KClass<T>): CommandValueArgumentParser<T>? =
+        (this.list.firstOrNull { kClass == it.klass }?.parser
+            ?: this.list.firstOrNull { kClass.isSubclassOf(it.klass) }?.parser) as CommandValueArgumentParser<T>?
 
     override fun toList(): List<ParserPair<*>> = list
 }
@@ -192,6 +205,9 @@ public class SimpleCommandArgumentContext(
  */
 @JvmSynthetic
 public fun buildCommandArgumentContext(block: CommandArgumentContextBuilder.() -> Unit): CommandArgumentContext {
+    contract {
+        callsInPlace(block, EXACTLY_ONCE)
+    }
     return CommandArgumentContextBuilder().apply(block).build()
 }
 

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/descriptor/CommandArgumentParserBuiltins.kt

@@ -7,6 +7,8 @@
  * https://github.com/mamoe/mirai/blob/master/LICENSE
  */
 
+@file:Suppress("EXPOSED_SUPER_CLASS")
+
 package net.mamoe.mirai.console.command.descriptor
 
 import net.mamoe.mirai.Bot
@@ -25,7 +27,7 @@ import net.mamoe.mirai.message.data.*
 /**
  * 使用 [String.toInt] 解析
  */
-public object IntValueArgumentParser : InternalCommandValueArgumentParserExtensions<Int> {
+public object IntValueArgumentParser : InternalCommandValueArgumentParserExtensions<Int>() {
     public override fun parse(raw: String, sender: CommandSender): Int =
         raw.toIntOrNull() ?: illegalArgument("无法解析 $raw 为整数")
 }
@@ -33,7 +35,7 @@ public object IntValueArgumentParser : InternalCommandValueArgumentParserExtensi
 /**
  * 使用 [String.toLong] 解析
  */
-public object LongValueArgumentParser : InternalCommandValueArgumentParserExtensions<Long> {
+public object LongValueArgumentParser : InternalCommandValueArgumentParserExtensions<Long>() {
     public override fun parse(raw: String, sender: CommandSender): Long =
         raw.toLongOrNull() ?: illegalArgument("无法解析 $raw 为长整数")
 }
@@ -41,7 +43,7 @@ public object LongValueArgumentParser : InternalCommandValueArgumentParserExtens
 /**
  * 使用 [String.toShort] 解析
  */
-public object ShortValueArgumentParser : InternalCommandValueArgumentParserExtensions<Short> {
+public object ShortValueArgumentParser : InternalCommandValueArgumentParserExtensions<Short>() {
     public override fun parse(raw: String, sender: CommandSender): Short =
         raw.toShortOrNull() ?: illegalArgument("无法解析 $raw 为短整数")
 }
@@ -49,7 +51,7 @@ public object ShortValueArgumentParser : InternalCommandValueArgumentParserExten
 /**
  * 使用 [String.toByte] 解析
  */
-public object ByteValueArgumentParser : InternalCommandValueArgumentParserExtensions<Byte> {
+public object ByteValueArgumentParser : InternalCommandValueArgumentParserExtensions<Byte>() {
     public override fun parse(raw: String, sender: CommandSender): Byte =
         raw.toByteOrNull() ?: illegalArgument("无法解析 $raw 为字节")
 }
@@ -57,7 +59,7 @@ public object ByteValueArgumentParser : InternalCommandValueArgumentParserExtens
 /**
  * 使用 [String.toDouble] 解析
  */
-public object DoubleValueArgumentParser : InternalCommandValueArgumentParserExtensions<Double> {
+public object DoubleValueArgumentParser : InternalCommandValueArgumentParserExtensions<Double>() {
     public override fun parse(raw: String, sender: CommandSender): Double =
         raw.toDoubleOrNull() ?: illegalArgument("无法解析 $raw 为小数")
 }
@@ -65,7 +67,7 @@ public object DoubleValueArgumentParser : InternalCommandValueArgumentParserExte
 /**
  * 使用 [String.toFloat] 解析
  */
-public object FloatValueArgumentParser : InternalCommandValueArgumentParserExtensions<Float> {
+public object FloatValueArgumentParser : InternalCommandValueArgumentParserExtensions<Float>() {
     public override fun parse(raw: String, sender: CommandSender): Float =
         raw.toFloatOrNull() ?: illegalArgument("无法解析 $raw 为小数")
 }
@@ -73,14 +75,14 @@ public object FloatValueArgumentParser : InternalCommandValueArgumentParserExten
 /**
  * 直接返回 [String], 或取用 [SingleMessage.contentToString]
  */
-public object StringValueArgumentParser : InternalCommandValueArgumentParserExtensions<String> {
+public object StringValueArgumentParser : InternalCommandValueArgumentParserExtensions<String>() {
     public override fun parse(raw: String, sender: CommandSender): String = raw
 }
 
 /**
  * 解析 [String] 通过 [Image].
  */
-public object ImageValueArgumentParser : InternalCommandValueArgumentParserExtensions<Image> {
+public object ImageValueArgumentParser : InternalCommandValueArgumentParserExtensions<Image>() {
     public override fun parse(raw: String, sender: CommandSender): Image {
         return kotlin.runCatching {
             Image(raw)
@@ -95,7 +97,7 @@ public object ImageValueArgumentParser : InternalCommandValueArgumentParserExten
     }
 }
 
-public object PlainTextValueArgumentParser : InternalCommandValueArgumentParserExtensions<PlainText> {
+public object PlainTextValueArgumentParser : InternalCommandValueArgumentParserExtensions<PlainText>() {
     public override fun parse(raw: String, sender: CommandSender): PlainText {
         return PlainText(raw)
     }
@@ -109,7 +111,7 @@ public object PlainTextValueArgumentParser : InternalCommandValueArgumentParserE
 /**
  * 当字符串内容为(不区分大小写) "true", "yes", "enabled"
  */
-public object BooleanValueArgumentParser : InternalCommandValueArgumentParserExtensions<Boolean> {
+public object BooleanValueArgumentParser : InternalCommandValueArgumentParserExtensions<Boolean>() {
     public override fun parse(raw: String, sender: CommandSender): Boolean = raw.trim().let { str ->
         str.equals("true", ignoreCase = true)
             || str.equals("yes", ignoreCase = true)
@@ -121,7 +123,7 @@ public object BooleanValueArgumentParser : InternalCommandValueArgumentParserExt
 /**
  * 根据 [Bot.id] 解析一个登录后的 [Bot]
  */
-public object ExistingBotValueArgumentParser : InternalCommandValueArgumentParserExtensions<Bot> {
+public object ExistingBotValueArgumentParser : InternalCommandValueArgumentParserExtensions<Bot>() {
     public override fun parse(raw: String, sender: CommandSender): Bot =
         if (raw == "~") sender.inferBotOrFail()
         else raw.findBotOrFail()
@@ -136,7 +138,7 @@ public object ExistingBotValueArgumentParser : InternalCommandValueArgumentParse
 /**
  * 解析任意一个存在的好友.
  */
-public object ExistingFriendValueArgumentParser : InternalCommandValueArgumentParserExtensions<Friend> {
+public object ExistingFriendValueArgumentParser : InternalCommandValueArgumentParserExtensions<Friend>() {
     private val syntax = """
         - `botId.friendId`
         - `botId.friendNick` (模糊搜索, 寻找最优匹配)
@@ -175,7 +177,7 @@ public object ExistingFriendValueArgumentParser : InternalCommandValueArgumentPa
 /**
  * 解析任意一个存在的群.
  */
-public object ExistingGroupValueArgumentParser : InternalCommandValueArgumentParserExtensions<Group> {
+public object ExistingGroupValueArgumentParser : InternalCommandValueArgumentParserExtensions<Group>() {
     private val syntax = """
         - `botId.groupId`
         - `~` (指代指令调用人自己所在群. 仅群聊天环境下)
@@ -202,7 +204,7 @@ public object ExistingGroupValueArgumentParser : InternalCommandValueArgumentPar
     }
 }
 
-public object ExistingUserValueArgumentParser : InternalCommandValueArgumentParserExtensions<User> {
+public object ExistingUserValueArgumentParser : InternalCommandValueArgumentParserExtensions<User>() {
     private val syntax: String = """
          - `botId.groupId.memberId`
          - `botId.groupId.memberCard` (模糊搜索, 寻找最优匹配)
@@ -246,7 +248,7 @@ public object ExistingUserValueArgumentParser : InternalCommandValueArgumentPars
 }
 
 
-public object ExistingContactValueArgumentParser : InternalCommandValueArgumentParserExtensions<Contact> {
+public object ExistingContactValueArgumentParser : InternalCommandValueArgumentParserExtensions<Contact>() {
     private val syntax: String = """
          - `botId.groupId.memberId`
          - `botId.groupId.memberCard` (模糊搜索, 寻找最优匹配)
@@ -286,7 +288,7 @@ public object ExistingContactValueArgumentParser : InternalCommandValueArgumentP
 /**
  * 解析任意一个群成员.
  */
-public object ExistingMemberValueArgumentParser : InternalCommandValueArgumentParserExtensions<Member> {
+public object ExistingMemberValueArgumentParser : InternalCommandValueArgumentParserExtensions<Member>() {
     private val syntax: String = """
          - `botId.groupId.memberId`
          - `botId.groupId.memberCard` (模糊搜索, 寻找最优匹配)
@@ -333,7 +335,7 @@ public object ExistingMemberValueArgumentParser : InternalCommandValueArgumentPa
     }
 }
 
-public object PermissionIdValueArgumentParser : CommandValueArgumentParser<PermissionId> {
+public object PermissionIdValueArgumentParser : InternalCommandValueArgumentParserExtensions<PermissionId>() {
     override fun parse(raw: String, sender: CommandSender): PermissionId {
         return kotlin.runCatching { PermissionId.parseFromString(raw) }.getOrElse {
             illegalArgument("无法解析 $raw 为 PermissionId")
@@ -341,7 +343,7 @@ public object PermissionIdValueArgumentParser : CommandValueArgumentParser<Permi
     }
 }
 
-public object PermitteeIdValueArgumentParser : CommandValueArgumentParser<PermitteeId> {
+public object PermitteeIdValueArgumentParser : InternalCommandValueArgumentParserExtensions<PermitteeId>() {
     override fun parse(raw: String, sender: CommandSender): PermitteeId {
         return if (raw == "~") sender.permitteeId
         else kotlin.runCatching { AbstractPermitteeId.parseFromString(raw) }.getOrElse {
@@ -363,26 +365,26 @@ public object RawContentValueArgumentParser : CommandValueArgumentParser<Message
     override fun parse(raw: MessageContent, sender: CommandSender): MessageContent = raw
 }
 
-internal interface InternalCommandValueArgumentParserExtensions<T : Any> : CommandValueArgumentParser<T> {
-    fun String.parseToLongOrFail(): Long = toLongOrNull() ?: illegalArgument("无法解析 $this 为整数")
+internal abstract class InternalCommandValueArgumentParserExtensions<T : Any> : AbstractCommandValueArgumentParser<T>() {
+    private fun String.parseToLongOrFail(): Long = toLongOrNull() ?: illegalArgument("无法解析 $this 为整数")
 
-    fun Long.findBotOrFail(): Bot = Bot.getInstanceOrNull(this) ?: illegalArgument("无法找到 Bot: $this")
+    protected fun Long.findBotOrFail(): Bot = Bot.getInstanceOrNull(this) ?: illegalArgument("无法找到 Bot: $this")
 
-    fun String.findBotOrFail(): Bot =
+    protected fun String.findBotOrFail(): Bot =
         Bot.getInstanceOrNull(this.parseToLongOrFail()) ?: illegalArgument("无法找到 Bot: $this")
 
-    fun Bot.findGroupOrFail(id: Long): Group = getGroupOrNull(id) ?: illegalArgument("无法找到群: $this")
+    protected fun Bot.findGroupOrFail(id: Long): Group = getGroupOrNull(id) ?: illegalArgument("无法找到群: $this")
 
-    fun Bot.findGroupOrFail(id: String): Group =
+    protected fun Bot.findGroupOrFail(id: String): Group =
         getGroupOrNull(id.parseToLongOrFail()) ?: illegalArgument("无法找到群: $this")
 
-    fun Bot.findFriendOrFail(id: String): Friend =
+    protected fun Bot.findFriendOrFail(id: String): Friend =
         getFriendOrNull(id.parseToLongOrFail()) ?: illegalArgument("无法找到好友: $this")
 
-    fun Bot.findMemberOrFail(id: String): Friend =
+    protected fun Bot.findMemberOrFail(id: String): Friend =
         getFriendOrNull(id.parseToLongOrFail()) ?: illegalArgument("无法找到群员: $this")
 
-    fun Group.findMemberOrFail(idOrCard: String): Member {
+    protected fun Group.findMemberOrFail(idOrCard: String): Member {
         if (idOrCard == "\$") return members.randomOrNull() ?: illegalArgument("当前语境下无法推断随机群员")
         idOrCard.toLongOrNull()?.let { getOrNull(it) }?.let { return it }
         this.members.singleOrNull { it.nameCardOrNick.contains(idOrCard) }?.let { return it }
@@ -405,23 +407,21 @@ internal interface InternalCommandValueArgumentParserExtensions<T : Any> : Comma
         }
     }
 
-    fun CommandSender.inferBotOrFail(): Bot =
+    protected fun CommandSender.inferBotOrFail(): Bot =
         (this as? UserCommandSender)?.bot
             ?: Bot.botInstancesSequence.singleOrNull()
             ?: illegalArgument("当前语境下无法推断目标 Bot, 因为目前有多个 Bot 在线.")
 
-    fun CommandSender.inferGroupOrFail(): Group =
+    protected fun CommandSender.inferGroupOrFail(): Group =
         inferGroup() ?: illegalArgument("当前语境下无法推断目标群")
 
-    fun CommandSender.inferGroup(): Group? = (this as? GroupAwareCommandSender)?.group
+    protected fun CommandSender.inferGroup(): Group? = (this as? GroupAwareCommandSender)?.group
 
-    fun CommandSender.inferFriendOrFail(): Friend =
+    protected fun CommandSender.inferFriendOrFail(): Friend =
         (this as? FriendCommandSender)?.user ?: illegalArgument("当前语境下无法推断目标好友")
 }
 
-internal fun Double.toDecimalPlace(n: Int): String {
-    return "%.${n}f".format(this)
-}
+internal fun Double.toDecimalPlace(n: Int): String = "%.${n}f".format(this)
 
 internal fun String.truncate(lengthLimit: Int, replacement: String = "..."): String = buildString {
     var lengthSum = 0

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/descriptor/CommandArgumentParserException.kt

@@ -12,6 +12,7 @@
 package net.mamoe.mirai.console.command.descriptor
 
 import net.mamoe.mirai.console.command.IllegalCommandArgumentException
+import net.mamoe.mirai.console.command.descriptor.AbstractCommandValueArgumentParser.Companion.illegalArgument
 
 /**
  * 在解析参数时遇到的 _正常_ 错误. 如参数不符合规范等.
@@ -20,7 +21,7 @@ import net.mamoe.mirai.console.command.IllegalCommandArgumentException
  *
  * @see IllegalCommandArgumentException
  * @see CommandValueArgumentParser
- * @see CommandValueArgumentParser.illegalArgument
+ * @see AbstractCommandValueArgumentParser.illegalArgument
  */
 public class CommandArgumentParserException : IllegalCommandArgumentException {
     public constructor() : super()

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/descriptor/CommandValueArgumentParser.kt

@@ -16,10 +16,9 @@ import net.mamoe.mirai.console.command.CommandManager
 import net.mamoe.mirai.console.command.CommandSender
 import net.mamoe.mirai.console.command.CompositeCommand
 import net.mamoe.mirai.console.command.SimpleCommand
+import net.mamoe.mirai.console.command.descriptor.CommandValueArgumentParser.Companion.parse
 import net.mamoe.mirai.contact.*
-import net.mamoe.mirai.message.data.MessageContent
-import net.mamoe.mirai.message.data.SingleMessage
-import net.mamoe.mirai.message.data.content
+import net.mamoe.mirai.message.data.*
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
 
@@ -78,68 +77,76 @@ public interface CommandValueArgumentParser<out T : Any> {
      */
     @Throws(CommandArgumentParserException::class)
     public fun parse(raw: MessageContent, sender: CommandSender): T = parse(raw.content, sender)
-}
 
-/**
- * 使用原 [this] 解析, 成功后使用 [mapper] 映射为另一个类型.
- */
-public fun <T : Any, R : Any> CommandValueArgumentParser<T>.map(
-    mapper: CommandValueArgumentParser<R>.(T) -> R,
-): CommandValueArgumentParser<R> = MappingCommandValueArgumentParser(this, mapper)
-
-private class MappingCommandValueArgumentParser<T : Any, R : Any>(
-    private val original: CommandValueArgumentParser<T>,
-    private val mapper: CommandValueArgumentParser<R>.(T) -> R,
-) : CommandValueArgumentParser<R> {
-    override fun parse(raw: String, sender: CommandSender): R = mapper(original.parse(raw, sender))
-    override fun parse(raw: MessageContent, sender: CommandSender): R = mapper(original.parse(raw, sender))
-}
-
-/**
+    public companion object {
+        /**
          * 解析一个字符串或 [SingleMessage] 为 [T] 类型参数
          *
          * @throws IllegalArgumentException 当 [raw] 既不是 [SingleMessage], 也不是 [String] 时抛出.
+         *
+         * @see CommandValueArgumentParser.parse
          */
-@JvmSynthetic
-@Throws(IllegalArgumentException::class)
-public fun <T : Any> CommandValueArgumentParser<T>.parse(raw: Any, sender: CommandSender): T {
-    contract {
-        returns() implies (raw is String || raw is SingleMessage)
-    }
-
+        @JvmStatic
+        @Throws(IllegalArgumentException::class)
+        public fun <T : Any> CommandValueArgumentParser<T>.parse(raw: Message, sender: CommandSender): T {
             return when (raw) {
-        is String -> parse(raw, sender)
+                is PlainText -> parse(raw.content, sender)
                 is MessageContent -> parse(raw, sender)
                 else -> throw IllegalArgumentException("Illegal raw argument type: ${raw::class.qualifiedName}")
             }
+        }
+
+        /**
+         * 使用原 [this] 解析, 成功后使用 [mapper] 映射为另一个类型.
+         */
+        @JvmStatic
+        public fun <Original : Any, Result : Any> CommandValueArgumentParser<Original>.map(
+            mapper: MappingCommandValueArgumentParser<Original, Result>.(Original) -> Result,
+        ): CommandValueArgumentParser<Result> = MappingCommandValueArgumentParser(this, mapper)
+    }
 }
 
 /**
+ * @see CommandValueArgumentParser 的基础实现.
+ */
+public abstract class AbstractCommandValueArgumentParser<T : Any> : CommandValueArgumentParser<T> {
+    public companion object {
+        /**
          * 抛出一个 [CommandArgumentParserException] 的捷径
          *
          * @throws CommandArgumentParserException
          */
-@Suppress("unused")
-@JvmSynthetic
-@Throws(CommandArgumentParserException::class)
-public inline fun CommandValueArgumentParser<*>.illegalArgument(message: String, cause: Throwable? = null): Nothing {
+        @JvmStatic
+        @JvmSynthetic
+        @Throws(CommandArgumentParserException::class)
+        protected inline fun CommandValueArgumentParser<*>.illegalArgument(message: String, cause: Throwable? = null): Nothing =
             throw CommandArgumentParserException(message, cause)
-}
 
-/**
+        /**
          * 检查参数 [condition]. 当它为 `false` 时调用 [message] 并以其返回值作为消息, 抛出异常 [CommandArgumentParserException]
          *
          * @throws CommandArgumentParserException
          */
-@Throws(CommandArgumentParserException::class)
-@JvmSynthetic
-public inline fun CommandValueArgumentParser<*>.checkArgument(
+        @JvmStatic
+        @Throws(CommandArgumentParserException::class)
+        @JvmSynthetic
+        protected inline fun CommandValueArgumentParser<*>.checkArgument(
             condition: Boolean,
             crossinline message: () -> String = { "Check failed." },
-) {
+        ) {
             contract {
                 returns() implies condition
                 callsInPlace(message, InvocationKind.AT_MOST_ONCE)
             }
             if (!condition) illegalArgument(message())
+        }
+    }
+}
+
+public class MappingCommandValueArgumentParser<T : Any, R : Any>(
+    private val original: CommandValueArgumentParser<T>,
+    private val mapper: MappingCommandValueArgumentParser<T, R>.(T) -> R,
+) : AbstractCommandValueArgumentParser<R>() {
+    override fun parse(raw: String, sender: CommandSender): R = mapper(original.parse(raw, sender))
+    override fun parse(raw: MessageContent, sender: CommandSender): R = mapper(original.parse(raw, sender))
 }

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/java/JCommand.kt

@@ -1,25 +0,0 @@
-/*
- * Copyright 2019-2020 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 AFFERO GENERAL PUBLIC LICENSE version 3 license that can be found via the following link.
- *
- * https://github.com/mamoe/mirai/blob/master/LICENSE
- */
-
-package net.mamoe.mirai.console.command.java
-
-import net.mamoe.mirai.console.command.Command
-import net.mamoe.mirai.console.util.ConsoleExperimentalApi
-
-/**
- * 为 Java 用户添加协程帮助的 [Command].
- *
- * 注意, [JSimpleCommand], [JCompositeCommand], [JRawCommand] 都不实现这个接口. [JCommand] 只设计为 Java 使用者自己实现 [Command] 相关内容.
- *
- * @see Command
- */
-@ConsoleExperimentalApi("Not yet supported")
-public interface JCommand : Command {
-    // TODO: 2020/10/18 JCommand
-}

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/java/JCompositeCommand.kt

@@ -18,7 +18,6 @@ import net.mamoe.mirai.console.command.descriptor.buildCommandArgumentContext
 import net.mamoe.mirai.console.compiler.common.ResolveContext
 import net.mamoe.mirai.console.compiler.common.ResolveContext.Kind.COMMAND_NAME
 import net.mamoe.mirai.console.permission.Permission
-import net.mamoe.mirai.console.util.ConsoleExperimentalApi
 
 /**
  * 复合指令. 指令注册时候会通过反射构造指令解析器.
@@ -70,7 +69,6 @@ import net.mamoe.mirai.console.util.ConsoleExperimentalApi
  *
  * @see buildCommandArgumentContext
  */
-@ConsoleExperimentalApi("Not yet supported")
 public abstract class JCompositeCommand
 @JvmOverloads constructor(
     owner: CommandOwner,

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/java/JRawCommand.kt

@@ -18,7 +18,6 @@ import net.mamoe.mirai.console.compiler.common.ResolveContext
 import net.mamoe.mirai.console.compiler.common.ResolveContext.Kind.COMMAND_NAME
 import net.mamoe.mirai.console.internal.command.createOrFindCommandPermission
 import net.mamoe.mirai.console.permission.Permission
-import net.mamoe.mirai.console.util.ConsoleExperimentalApi
 
 /**
  * 供 Java 用户继承
@@ -46,7 +45,6 @@ import net.mamoe.mirai.console.util.ConsoleExperimentalApi
  *
  * @see JRawCommand
  */
-@ConsoleExperimentalApi("Not yet supported")
 public abstract class JRawCommand
 @JvmOverloads constructor(
     /**

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/java/JSimpleCommand.kt

@@ -17,7 +17,6 @@ import net.mamoe.mirai.console.command.descriptor.ExperimentalCommandDescriptors
 import net.mamoe.mirai.console.compiler.common.ResolveContext
 import net.mamoe.mirai.console.compiler.common.ResolveContext.Kind.COMMAND_NAME
 import net.mamoe.mirai.console.permission.Permission
-import net.mamoe.mirai.console.util.ConsoleExperimentalApi
 
 /**
  * Java 实现:
@@ -43,7 +42,6 @@ import net.mamoe.mirai.console.util.ConsoleExperimentalApi
  * @see SimpleCommand
  * @see [CommandManager.executeCommand]
  */
-@ConsoleExperimentalApi("Not yet supported")
 public abstract class JSimpleCommand(
     owner: CommandOwner,
     @ResolveContext(COMMAND_NAME) primaryName: String,

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/resolve/BuiltInCommandCallResolver.kt

@@ -77,7 +77,7 @@ public object BuiltInCommandCallResolver : CommandCallResolver {
                 } else {
                     if (valueArguments.size > valueParameters.size && zipped.last().first.isVararg) {
                         // merge vararg arguments
-                        val (varargParameter, varargFirstArgument)
+                        val (varargParameter, _)
                             = zipped.removeLast()
 
                         zipped.add(varargParameter to DefaultCommandValueArgument(valueArguments.drop(zipped.size).map { it.value }.asMessageChain()))

backend/mirai-console/src/main/kotlin/net/mamoe/mirai/console/command/resolve/ResolvedCommandCall.kt

@@ -13,6 +13,7 @@ import net.mamoe.mirai.console.command.Command
 import net.mamoe.mirai.console.command.CommandSender
 import net.mamoe.mirai.console.command.CompositeCommand
 import net.mamoe.mirai.console.command.descriptor.*
+import net.mamoe.mirai.console.command.descriptor.CommandValueArgumentParser.Companion.parse
 import net.mamoe.mirai.console.command.parse.CommandCall
 import net.mamoe.mirai.console.command.parse.CommandValueArgument
 import net.mamoe.mirai.console.command.parse.mapToTypeOrNull