Add better howto's to commands

src/main/kotlin/nl/voidcorp/dbot/UnityBot.kt

@@ -119,6 +119,7 @@ fun main(args: Array<String>) {
                         .appendDescription(cmd.help)
                         .setColor(event.selfMember.color).setFooter("Requested by ${event.member.effectiveName}", event.author.effectiveAvatarUrl).setTimestamp(LocalDateTime.now())
                 if (cmd.aliases.isNotEmpty()) eb.addField("Aliases", cmd.aliases.joinToString { "`$it`" }, false)
+                eb.addField("Usage", "`!${cmd.howTo.emptyOr(cmd.name)}`", false)
 
             }
             event.args == "help" -> {

src/main/kotlin/nl/voidcorp/dbot/Util.kt

@@ -16,12 +16,14 @@ fun <E> List<E>.random(): E = this[random.nextInt(this.size)]
 fun List<Command>.catMap(): Map<String, List<Command>> {
     val m = mutableMapOf<String, MutableList<Command>>()
     for (c in this) {
-        val cname = if (c.category==null) "Unknown" else c.category.name
+        val cname = if (c.category == null) "Unknown" else c.category.name
         if (!m.containsKey(cname)) {
             m[cname] = mutableListOf()
         }
 
-        m[cname]!!+=c
+        m[cname]!! += c
     }
     return m
-}
+}
+
+fun String.emptyOr(other: String): String = if (this.isEmpty()) other else this

src/main/kotlin/nl/voidcorp/dbot/commands/Music.kt

@@ -22,7 +22,7 @@ fun initMusic() {
     AudioSourceManagers.registerRemoteSources(playerManager)
 
 
-    val queueCommand = UnityMusicCommand("queue", aliases = *arrayOf("q"), help = "Use this command to queue a song, if you don't add a link it will search on youtube with the specified arguments\n\nExecute with no arguments to view the current queue!") { event, scheduler ->
+    val queueCommand = UnityMusicCommand("queue", aliases = *arrayOf("q"), help = "Use this command to queue a song, if you don't add a link it will search on youtube with the specified arguments\n\nExecute with no arguments to view the current queue!", howTo = "q [link]") { event, scheduler ->
 
         if (event.args.isEmpty()) {
             if (!guildMusicMap.containsKey(event.guild.idLong) || (guildMusicMap[event.guild.idLong]!!.player.playingTrack == null))
@@ -58,7 +58,7 @@ fun initMusic() {
         })
     }
 
-    val ytCommand = UnityMusicCommand("youtube", aliases = *arrayOf("yt"), help = "Search YouTube for a song!") { event, scheduler ->
+    val ytCommand = UnityMusicCommand("youtube", aliases = *arrayOf("yt"), help = "Search YouTube for a song!", howTo = "youtube <search term or link>") { event, scheduler ->
         if (event.args.isEmpty()) {
             event.reply("Please supply a song name or URL!")
             return@UnityMusicCommand
@@ -87,7 +87,7 @@ fun initMusic() {
         })
     }
 
-    val soundcloudCommand = UnityMusicCommand("soundcloud", help = "Play a song via SoundCloud!", aliases = *arrayOf("sc")) { event, scheduler ->
+    val soundcloudCommand = UnityMusicCommand("soundcloud", help = "Play a song via SoundCloud!", aliases = *arrayOf("sc"), howTo = "sc <link or search term>") { event, scheduler ->
         if (event.args.isEmpty()) {
             event.reply("Please supply a song name or URL!")
             return@UnityMusicCommand
@@ -117,7 +117,7 @@ fun initMusic() {
         })
     }
 
-    val playCommand = UnityMusicCommand("play", "Force this song to be the next!", aliases = *arrayOf("p")) { event, scheduler ->
+    val playCommand = UnityMusicCommand("play", "Force this song to be the next!", aliases = *arrayOf("p"), howTo = "play <url>") { event, scheduler ->
         if (event.args.isEmpty()) {
             event.reply("Please supply a song name or URL!")
             return@UnityMusicCommand

src/main/kotlin/nl/voidcorp/dbot/commands/UnityCommand.kt

@@ -44,7 +44,8 @@ val generalCategory = Command.Category("General commands") {
 
 open class UnityCommand(name: String, help: String = "",
                         category: Category = generalCategory,
-                        arguments: String = "", vararg aliases: String = arrayOf(), val exec: (event: CommandEvent) -> Unit) : Command() {
+                        arguments: String = "", vararg aliases: String = arrayOf(), val howTo: String = "",
+                        val exec: (event: CommandEvent) -> Unit) : Command() {
     init {
         super.name = name
         super.help = help
@@ -58,7 +59,9 @@ open class UnityCommand(name: String, help: String = "",
 
 class UnityMusicCommand(name: String, help: String = "",
                         category: Category = musicCategory,
-                        arguments: String = "", vararg aliases: String = arrayOf(name.first().toString()), val mExec: (event: CommandEvent, scheduler: TrackScheduler) -> Unit) : UnityCommand(name, help, category, arguments, *aliases, exec = {}) {
+                        arguments: String = "", vararg aliases: String = arrayOf(name.first().toString()),
+                        howTo: String = "",
+                        val mExec: (event: CommandEvent, scheduler: TrackScheduler) -> Unit) : UnityCommand(name, help, category, arguments, *aliases, howTo = howTo, exec = {}) {
     override fun execute(event: CommandEvent) {
         val scheduler = if (guildMusicMap.containsKey(event.guild.idLong)) guildMusicMap[event.guild.idLong]!! else {
             val channel = event.guild.voiceChannels.firstOrNull { it.members.contains(event.member) }