make quickcheck tests friendlier to read.

darcs-hash:20070505175415-72aca-2129b8432f6f2ddb9d1498b0503b86c401020194

1 files changed, 1 insertions, 1 deletions

diff --git a/StackSet.hs b/StackSet.hs
index 7b47e06..3e35f53 100644
--- a/StackSet.hs
+++ b/StackSet.hs
@@ -46,7 +46,7 @@ data StackSet i j a =
         , stacks   :: !(M.Map i ([a], [a])) -- ^ screen -> (floating, normal)
         , focus    :: !(M.Map i a)          -- ^ the window focused in each stack
         , cache    :: !(M.Map a i)          -- ^ a cache of windows back to their stacks
-        } deriving (Eq, Show)
+        } deriving (Eq, Show, Read)
 
 -- The cache is used to check on insertion that we don't already have
 -- this window managed on another stack