[xmonad] Shifting client-instances to workspaces

[1126]

Hello!

As this is my first submission to a mailinglist ever, I hope I do 
everything right ;)

I am trying to learn Haskell, and as my fascination for this language 
grew, I considered shifting from i3 to xmonad. So far, everything more or 
less works.

Now I am trying to pimp my configuration from a minimal one to a more 
sophisticated one. I added the ability to shift clients automatically to a 
workspace. So, when I start Firefox it is opened on my www-workspace 
automatically. I want the same for Irssi and Alpine and my Emacs. I want 
them opened on the communiaction-workspace, or the coding-workspace ;)

But all of them are running withing URxvt, so the class is always URxvt.

In i3 you are able to shift a client-instance to a workspace, like so:

 	assign [class="URxvt" instance="irssi"] -> 2|com

Is something similar possible in xmonad? And if so, how?

Thanks in advance,
greetings from Cologne,
1126!