new module DynamicWorkspaces to add and remove workspaces.

DynamicWorkspaces.hs

@@ -0,0 +1,52 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonadContrib.DynamicWorkspaces
+-- Copyright   :  (c) David Roundy <droundy@darcs.net>
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  David Roundy <droundy@darcs.net>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Provides bindings to add and delete workspaces.  Note that you may only
+-- delete a workspace that is already empty.
+--
+-----------------------------------------------------------------------------
+
+module XMonadContrib.DynamicWorkspaces (
+                                         -- * Usage
+                                         -- $usage
+                                         addWorkspace, removeWorkspace
+                                       ) where
+
+import XMonad ( X )
+import Operations ( windows )
+import StackSet ( tagMember, StackSet(..), Screen(..), Workspace(..) )
+
+-- $usage
+-- You can use this module with the following in your Config.hs file:
+-- 
+-- > import XMonadContrib.DynamicWorkspaces
+--
+-- >   , ((modMask .|. shiftMask, xK_Up), addWorkspace)
+-- >   , ((modMask .|. shiftMask, xK_Down), removeWorkspace)
+
+addWorkspace :: X ()
+addWorkspace = windows addWorkspace'
+
+removeWorkspace :: X ()
+removeWorkspace = windows removeWorkspace'
+
+addWorkspace' :: (Enum i, Num i) => StackSet i a sid sd -> StackSet i a sid sd
+addWorkspace' s@(StackSet { current = scr@(Screen { workspace = w })
+                          , hidden = ws })
+    = s { current = scr { workspace = Workspace newtag Nothing }
+        , hidden = w:ws }
+    where (newtag:_) = filter (not . (`tagMember` s)) [0..]
+
+removeWorkspace' :: StackSet i a sid sd -> StackSet i a sid sd
+removeWorkspace' s@(StackSet { current = scr@(Screen { workspace = Workspace { stack = Nothing } })
+                             , hidden = (w:ws) })
+                    = s { current = scr { workspace = w }
+                        , hidden = ws }
+removeWorkspace' s = s

MetaModule.hs

@@ -31,6 +31,7 @@ import XMonadContrib.DeManage ()
 import XMonadContrib.Dmenu ()
 import XMonadContrib.DwmPromote ()
 import XMonadContrib.DynamicLog ()
+import XMonadContrib.DynamicWorkspaces ()
 import XMonadContrib.Dzen ()
 import XMonadContrib.FindEmptyWorkspace ()
 import XMonadContrib.FlexibleResize ()