fromList/toList have # of screens + another QC property

StackSet.hs

@@ -80,20 +80,21 @@ size = M.size . stacks
 
 -- | fromList. Build a new StackSet from a list of list of elements
 -- If there are duplicates in the list, the last occurence wins.
--- FIXME: This always makes a StackSet with 1 screen.
-fromList :: Ord a => (Int,[[a]]) -> StackSet a
-fromList (_,[]) = error "Cannot build a StackSet from an empty list"
+fromList :: Ord a => (Int,Int,[[a]]) -> StackSet a
+fromList (_,_,[]) = error "Cannot build a StackSet from an empty list"
 
-fromList (n,xs) | n < 0 || n >= length xs
+fromList (n,m,xs) | n < 0 || n >= length xs
                 = error $ "Cursor index is out of range: " ++ show (n, length xs)
+                  | m < 1 || m >  length xs
+                = error $ "Can't have more screens than workspaces: " ++ show (m, length xs)
 
-fromList (o,xs) = view o $ foldr (\(i,ys) s ->
-                                foldr (\a t -> insert a i t) s ys)
-                                    (empty (length xs) 1) (zip [0..] xs)
+fromList (o,m,xs) = view o $ foldr (\(i,ys) s ->
+                                  foldr (\a t -> insert a i t) s ys)
+                                      (empty (length xs) m) (zip [0..] xs)
 
 -- | toList. Flatten a stackset to a list of lists
-toList  :: StackSet a -> (Int,[[a]])
-toList x = (current x, map snd $ M.toList (stacks x))
+toList  :: StackSet a -> (Int,Int,[[a]])
+toList x = (current x, M.size $ screen2ws x, map snd $ M.toList (stacks x))
 
 -- | Push. Insert an element onto the top of the current stack.
 -- If the element is already in the current stack, it is moved to the top.