From 1bfe92f582721d705942b72174683e36f7f812fc Mon Sep 17 00:00:00 2001 From: David Roundy Date: Thu, 20 Sep 2007 19:45:29 +0200 Subject: add Read instance to Layout. darcs-hash:20070920174529-72aca-b1cf11419d5cccbf67edbc3a7bbb356502e9186d.gz --- XMonad.hs | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'XMonad.hs') diff --git a/XMonad.hs b/XMonad.hs index 56d7a00..a9253c9 100644 --- a/XMonad.hs +++ b/XMonad.hs @@ -134,8 +134,10 @@ atom_WM_STATE = getAtom "WM_STATE" data SomeLayout a = forall l. Layout l a => SomeLayout (l a) instance Show (SomeLayout a) where show (SomeLayout l) = show l +instance Read (SomeLayout a) where + readsPrec _ _ = [] -- We can't read an existential type!!! -class Show (layout a) => Layout layout a where +class (Show (layout a), Read (layout a)) => Layout layout a where doLayout :: layout a -> Rectangle -> Stack a -> X ([(a, Rectangle)], Maybe (layout a)) modifyLayout :: layout a -> SomeMessage -> X (Maybe (layout a)) -- cgit v1.2.3