Well, I am not using Dvorak actually but Neo2, but as I am using a matrix type keyboard (Truly Ergonomic) I have also shifted the numbers.
Therefore this construction in my xmonad.hs does not work ergonomically:
-- mod-[1..9], Switch to workspace N
-- mod-shift-[1..9], Move client to workspace N
--
[((m .|. modMask, k), windows $ f i)
| (i, k) <- zip (XMonad.workspaces conf) [xK_1 .. xK_9]
, (f, m) <- [(W.greedyView, 0), (W.shift, shiftMask)]
I want to change that, to be able to access the workspaces 1 to 9 with the keys 2 to 0.
How could I achive that? I have tried to change the third line to
| (i, k) <- zip (XMonad.workspaces conf) [xK_2 .. xK_0]
but then I could not access the 9th workspace. How do I have to change this? A short explanition would be nice, so to learn something about this construction (I learned Haskell many years ago and forgot most of it).
Your problem is that xK_2 is bigger than xK_0, so the list [xK_2 .. xK_0] is empty:
Prelude XMonad> xK_2
50
Prelude XMonad> xK_0
48
Prelude XMonad> [xK_2 .. xK_0]
[]
You'll want to use a bit longer list than that. There's at least two reasonable ways to do this; one is to just specify all of keys yourself manually:
Prelude XMonad> [xK_2, xK_3, xK_4, xK_5, xK_6, xK_7, xK_8, xK_9, xK_0]
[50,51,52,53,54,55,56,57,48]
What I would probably use is a bit shorter:
Prelude XMonad> [xK_2 .. xK_9] ++ [xK_0]
[50,51,52,53,54,55,56,57,48]
Remember to add some parentheses if it's part of a bigger expression.