diff options
| -rw-r--r-- | XMonad/Actions/GroupNavigation.hs | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/XMonad/Actions/GroupNavigation.hs b/XMonad/Actions/GroupNavigation.hs index adde3f9..306c0f2 100644 --- a/XMonad/Actions/GroupNavigation.hs +++ b/XMonad/Actions/GroupNavigation.hs @@ -37,7 +37,7 @@ import Data.Maybe import Data.Sequence as Seq import Data.Set as Set import Graphics.X11.Types -import Prelude hiding (concatMap, drop, elem, filter, null, reverse) +import Prelude hiding (concatMap, drop, elem, filter, foldl, foldr, null, reverse) import XMonad.Core import XMonad.ManageHook import XMonad.Operations @@ -174,12 +174,27 @@ updateHistory :: HistoryDB -> X HistoryDB updateHistory (HistoryDB oldcur oldhist) = withWindowSet $ \ss -> do let newcur = currentWindow ss wins = Set.fromList $ SS.allWindows ss - newhist = Seq.filter (flip Set.member wins) oldhist + newhist = flt (flip Set.member wins) oldhist return $ HistoryDB newcur (del newcur $ ins oldcur newhist) where ins x xs = maybe xs (<| xs) x - del x xs = maybe xs (\x' -> Seq.filter (/= x') xs) x + del x xs = maybe xs (\x' -> flt (/= x') xs) x +--- Two replacements for Seq.filter and Seq.breakl available only in +--- containers-0.3.0.0, which only ships with ghc 6.12. Once we +--- decide to no longer support ghc < 6.12, these should be replaced +--- with Seq.filter and Seq.breakl. + +flt :: (a -> Bool) -> Seq a -> Seq a +flt p = foldl (\xs x -> if p x then xs |> x else xs) Seq.empty + +brkl :: (a -> Bool) -> Seq a -> (Seq a, Seq a) +brkl p xs = flip Seq.splitAt xs + $ snd + $ foldr (\x (i, j) -> if p x then (i-1, i-1) else (i-1, j)) (l, l) xs + where + l = Seq.length xs + --- Some sequence helpers -------------------------------------------- -- Rotates the sequence by one position @@ -192,7 +207,7 @@ rotate xs = rotate' (viewl xs) -- Rotates the sequence until an element matching the given condition -- is at the beginning of the sequence. rotateTo :: (a -> Bool) -> Seq a -> Seq a -rotateTo cond xs = let (lxs, rxs) = breakl cond xs in rxs >< lxs +rotateTo cond xs = let (lxs, rxs) = brkl cond xs in rxs >< lxs --- A monadic find --------------------------------------------------- |