use func(string, string) string as formatter

server/player/handler.go

@@ -36,7 +36,7 @@ type Handler interface {
 	// HandleChat handles a message sent in the chat by a player. ctx.Cancel() may be called to cancel the
 	// message being sent in chat.
 	// The message may be changed by assigning to *message.
-	HandleChat(ctx *Context, format *string, message *string)
+	HandleChat(ctx *Context, formatter *func(username, message string) string, message *string)
 	// HandleFoodLoss handles the food bar of a player depleting naturally, for example because the player was
 	// sprinting and jumping. ctx.Cancel() may be called to cancel the food points being lost.
 	HandleFoodLoss(ctx *Context, from int, to *int)
@@ -171,7 +171,7 @@ func (NopHandler) HandleToggleSprint(*Context, bool)
 func (NopHandler) HandleToggleSneak(*Context, bool)                                        {}
 func (NopHandler) HandleCommandExecution(*Context, cmd.Command, []string)                  {}
 func (NopHandler) HandleTransfer(*Context, *net.UDPAddr)                                   {}
-func (NopHandler) HandleChat(*Context, *string, *string)                                   {}
+func (NopHandler) HandleChat(*Context, *func(username, message string) string, *string)    {}
 func (NopHandler) HandleSkinChange(*Context, *skin.Skin)                                   {}
 func (NopHandler) HandleFireExtinguish(*Context, cube.Pos)                                 {}
 func (NopHandler) HandleStartBreak(*Context, cube.Pos)                                     {}

server/player/player.go

@@ -314,13 +314,15 @@ func (p *Player) RemoveBossBar() {
 // Chat writes a message in the global chat (chat.Global). The message is prefixed with the name of the
 // player and is formatted following the rules of fmt.Sprintln.
 func (p *Player) Chat(msg ...any) {
-	f := "<%v> %v\n"
+	formatter := func(username, message string) string {
+		return fmt.Sprintf("<%v> %v", username, message)
+	}
 	message := format(msg)
 	ctx := event.C(p)
-	if p.Handler().HandleChat(ctx, &f, &message); ctx.Cancelled() {
+	if p.Handler().HandleChat(ctx, &formatter, &message); ctx.Cancelled() {
 		return
 	}
-	_, _ = fmt.Fprintf(chat.Global, f, p.Name(), message)
+	_, _ = fmt.Fprintf(chat.Global, formatter(p.Name(), message)+"\n")
 }
 
 // ExecuteCommand executes a command passed as the player. If the command could not be found, or if the usage