Type-safe Kotlin DSL

[sya-ri]

Description

The current Kotlin DSL requires casts, so it is not type-safe. We can't get the most out of Kotlin.

commandTree("sendmessageto") {
    playerArgument("player") {
        greedyStringArgument("msg") {
            anyExecutor { _, args ->
                val player: Player = args["player"] as Player
                val message: String = args["msg"] as String
                player.sendMessage(message)
            }
        }
    }
}

commandAPICommand("sendmessageto") {
    playerArgument("player")
    greedyStringArgument("msg")
    anyExecutor { _, args ->
        val player: Player = args["player"] as Player
        val message: String = args["msg"] as String
        player.sendMessage(message)
    }
}

from: Defining a simple message command

Expected code

commandTree("sendmessageto") {
    playerArgument("player") { getPlayer ->
        greedyStringArgument("msg") { getMessage ->
            anyExecutor { _, args ->
                val player = getPlayer(args) // Returns Player
                val message = getMessage(args) // Returns String
                player.sendMessage(message)
            }
        }
    }
}

I have confirmed that this code can actually be rewritten. You can try it out using this library: https://github.com/sya-ri/commandapi-kotlin-improved

In my library, the Kotlin DSL for CommandAPICommand is not supported, but we should be able to rewrite it similarly.

Extra details

If necessary, I would like to submit a PR for the changes made by my library 😉