make focus, up and down complete functions.

This is a rerun of my change to make (Stack a) never be empty.  Gives
us more type-safety.
This commit is contained in:
David Roundy 2007-06-12 15:05:55 +00:00
parent 4ffee115e1
commit 5f8202e79e
5 changed files with 76 additions and 74 deletions

View File

@ -88,11 +88,11 @@ main = do
-- TODO, general iterators for these lists.
sequence_ [ setInitialProperties w >> reveal w
| wk <- map W.workspace (W.current winset : W.visible winset)
, w <- W.integrate (W.stack wk) ]
, w <- W.integrate' (W.stack wk) ]
sequence_ [ setInitialProperties w >> hide w
| wk <- W.hidden winset
, w <- W.integrate (W.stack wk) ]
, w <- W.integrate' (W.stack wk) ]
mapM_ manage ws -- find new windows
logHook

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@ -134,7 +134,7 @@ windows f = do
-- and must be called on all visible workspaces.
broadcastMessage UnDoLayout
XState { windowset = old, layouts = fls, xineScreens = xinesc, statusGaps = gaps } <- get
let oldvisible = concatMap (W.integrate . W.stack . W.workspace) $ W.current old : W.visible old
let oldvisible = concatMap (W.integrate' . W.stack . W.workspace) $ W.current old : W.visible old
ws = f old
modify (\s -> s { windowset = ws })
d <- asks display
@ -145,8 +145,7 @@ windows f = do
this = W.view n ws
Just l = fmap fst $ M.lookup n fls
flt = filter (flip M.member (W.floating ws)) (W.index this)
tiled = W.filter (not . flip M.member (W.floating ws))
. W.stack . W.workspace . W.current $ this
tiled = W.filter (not . flip M.member (W.floating ws)) . W.stack . W.workspace . W.current $ this
(Rectangle sx sy sw sh) = genericIndex xinesc (W.screen w)
(gt,gb,gl,gr) = genericIndex gaps (W.screen w)
viewrect = Rectangle (sx + fromIntegral gl) (sy + fromIntegral gt)
@ -154,7 +153,7 @@ windows f = do
-- just the tiled windows:
-- now tile the windows on this workspace, modified by the gap
rs <- doLayout l viewrect tiled -- `mplus` doLayout full viewrect tiled
rs <- runLayout l viewrect tiled -- `mplus` doLayout full viewrect tiled
mapM_ (uncurry tileWindow) rs
-- now the floating windows:
@ -388,9 +387,7 @@ instance Message IncMasterN
-- simple fullscreen mode, just render all windows fullscreen.
-- a plea for tuple sections: map . (,sc)
full :: Layout
full = Layout { doLayout = \sc ws -> return $ case ws of
W.Empty -> []
(W.Node f _ _) -> [(f, sc)]
full = Layout { doLayout = \sc (W.Stack f _ _) -> return [(f, sc)]
, modifyLayout = const (return Nothing) } -- no changes
--

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@ -74,10 +74,11 @@
--
module StackSet (
StackSet(..), Workspace(..), Screen(..), Stack(..), RationalRect(..),
new, view, lookupWorkspace, peek, index, integrate, differentiate, focusUp, focusDown,
StackSet(..), Workspace(..), Screen(..), StackOrNot, Stack(..), RationalRect(..),
new, view, lookupWorkspace, peek, index, integrate, integrate', differentiate,
focusUp, focusDown,
focusWindow, member, findIndex, insertUp, delete, shift, filter,
swapMaster, swapUp, swapDown, modify, float, sink -- needed by users
swapMaster, swapUp, swapDown, modify, modify', float, sink -- needed by users
) where
import Prelude hiding (filter)
@ -141,7 +142,7 @@ data Screen i a sid = Screen { workspace :: !(Workspace i a), screen :: !sid }
-- |
-- A workspace is just a tag - its index - and a stack
--
data Workspace i a = Workspace { tag :: !i, stack :: Stack a }
data Workspace i a = Workspace { tag :: !i, stack :: StackOrNot a }
deriving (Show, Read, Eq)
data RationalRect = RationalRect Rational Rational Rational Rational
@ -165,10 +166,11 @@ data RationalRect = RationalRect Rational Rational Rational Rational
-- structures, it is the differentiation of a [a], and integrating it
-- back has a natural implementation used in 'index'.
--
data Stack a = Empty
| Node { focus :: !a -- focused thing in this set
, up :: [a] -- clowns to the left
, down :: [a] } -- jokers to the right
type StackOrNot a = Maybe (Stack a)
data Stack a = Stack { focus :: !a -- focused thing in this set
, up :: [a] -- clowns to the left
, down :: [a] } -- jokers to the right
deriving (Show, Read, Eq)
@ -189,7 +191,7 @@ new :: (Integral i, Integral s) => i -> s -> StackSet i a s
new n m | n > 0 && m > 0 = StackSet n cur visi unseen M.empty
| otherwise = abort "non-positive arguments to StackSet.new"
where (seen,unseen) = L.genericSplitAt m $ Workspace 0 Empty : [ Workspace i Empty | i <- [1 ..n-1]]
where (seen,unseen) = L.genericSplitAt m $ Workspace 0 Nothing : [ Workspace i Nothing | i <- [1 ..n-1]]
(cur:visi) = [ Screen i s | (i,s) <- zip seen [0..] ]
-- now zip up visibles with their screen id
@ -232,22 +234,27 @@ lookupWorkspace sc w = listToMaybe [ tag i | Screen i s <- current w : visible w
-- |
-- The 'with' function takes a default value, a function, and a
-- StackSet. If the current stack is Empty, 'with' returns the
-- StackSet. If the current stack is Nothing, 'with' returns the
-- default value. Otherwise, it applies the function to the stack,
-- returning the result. It is like 'maybe' for the focused workspace.
--
with :: b -> (Stack a -> b) -> StackSet i a s -> b
with dflt f s = case stack (workspace (current s)) of Empty -> dflt; v -> f v
-- TODO: ndm: a 'catch' proof here that 'f' only gets Node
-- constructors, hence all 'f's are safe below?
with dflt f = maybe dflt f . stack . workspace . current
-- |
-- Apply a function, and a default value for Empty, to modify the current stack.
-- Apply a function, and a default value for Nothing, to modify the current stack.
--
modify :: Stack a -> (Stack a -> Stack a) -> StackSet i a s -> StackSet i a s
modify :: StackOrNot a -> (Stack a -> StackOrNot a) -> StackSet i a s -> StackSet i a s
modify d f s = s { current = (current s)
{ workspace = (workspace (current s)) { stack = with d f s }}}
-- |
-- Apply a function to modify the current stack if it isn't empty, and we don't
-- want to empty it.
--
modify' :: (Stack a -> Stack a) -> StackSet i a s -> StackSet i a s
modify' f = modify Nothing (Just . f)
-- |
-- /O(1)/. Extract the focused element of the current stack.
-- Return Just that element, or Nothing for an empty stack.
@ -259,27 +266,27 @@ peek = with Nothing (return . focus)
-- /O(n)/. Flatten a Stack into a list.
--
integrate :: Stack a -> [a]
integrate Empty = []
integrate (Node x l r) = reverse l ++ x : r
integrate (Stack x l r) = reverse l ++ x : r
integrate' :: StackOrNot a -> [a]
integrate' = maybe [] integrate
-- |
-- /O(n)/. Texture a list.
--
differentiate :: [a] -> Stack a
differentiate [] = Empty
differentiate (x:xs) = Node x [] xs
differentiate :: [a] -> StackOrNot a
differentiate [] = Nothing
differentiate (x:xs) = Just $ Stack x [] xs
-- |
-- /O(n)/. 'filter p s' returns the elements of 's' such that 'p' evaluates to
-- True. Order is preserved, and focus moves to the next node to the right (if
-- necessary).
filter :: (a -> Bool) -> Stack a -> Stack a
filter _ Empty = Empty
filter p (Node f ls rs) = case L.filter p (f:rs) of
(f':rs') -> Node f' (L.filter p ls) rs'
[] -> case reverse $ L.filter p ls of
[] -> Empty
(f':rs') -> Node f' [] rs'
filter :: (a -> Bool) -> Stack a -> StackOrNot a
filter p (Stack f ls rs) = case L.filter p (f:rs) of
(f':rs') -> Just $ Stack f' (L.filter p ls) rs'
[] -> do f':rs' <- return $ reverse $ L.filter p ls
Just $ Stack f' [] rs'
-- |
-- /O(s)/. Extract the stack on the current workspace, as a list.
@ -305,23 +312,22 @@ index = with [] integrate
-- the current stack.
--
focusUp, focusDown, swapUp, swapDown :: StackSet i a s -> StackSet i a s
focusUp = modify Empty focusUp'
focusDown = modify Empty (reverseStack . focusUp' . reverseStack)
focusUp = modify' focusUp'
focusDown = modify' (reverseStack . focusUp' . reverseStack)
swapUp = modify Empty swapUp'
swapDown = modify Empty (reverseStack . swapUp' . reverseStack)
swapUp = modify' swapUp'
swapDown = modify' (reverseStack . swapUp' . reverseStack)
focusUp', swapUp' :: Stack a -> Stack a
focusUp' (Node t (l:ls) rs) = Node l ls (t:rs)
focusUp' (Node t [] rs) = Node x xs [] where (x:xs) = reverse (t:rs)
focusUp' (Stack t (l:ls) rs) = Stack l ls (t:rs)
focusUp' (Stack t [] rs) = Stack x xs [] where (x:xs) = reverse (t:rs)
swapUp' (Node t (l:ls) rs) = Node t ls (l:rs)
swapUp' (Node t [] rs) = Node t (reverse rs) []
swapUp' (Stack t (l:ls) rs) = Stack t ls (l:rs)
swapUp' (Stack t [] rs) = Stack t (reverse rs) []
-- | reverse a stack: up becomes down and down becomes up.
reverseStack :: Stack a -> Stack a
reverseStack (Node t ls rs) = Node t rs ls
reverseStack x = x
reverseStack (Stack t ls rs) = Stack t rs ls
--
-- | /O(1) on current window, O(n) in general/. Focus the window 'w',
@ -348,8 +354,8 @@ member a s = maybe False (const True) (findIndex a s)
findIndex :: Eq a => a -> StackSet i a s -> Maybe i
findIndex a s = listToMaybe
[ tag w | w <- workspace (current s) : map workspace (visible s) ++ hidden s, has a (stack w) ]
where has _ Empty = False
has x (Node t l r) = x `elem` (t : l ++ r)
where has _ Nothing = False
has x (Just (Stack t l r)) = x `elem` (t : l ++ r)
-- ---------------------------------------------------------------------
-- | Modifying the stackset
@ -370,10 +376,10 @@ findIndex a s = listToMaybe
--
insertUp :: Eq a => a -> StackSet i a s -> StackSet i a s
insertUp a s = if member a s then s else insert
where insert = modify (Node a [] []) (\(Node t l r) -> Node a l (t:r)) s
where insert = modify (Just $ Stack a [] []) (\(Stack t l r) -> Just $ Stack a l (t:r)) s
-- insertDown :: a -> StackSet i a s -> StackSet i a s
-- insertDown a = modify (Node a [] []) $ \(Node t l r) -> Node a (t:l) r
-- insertDown a = modify (Stack a [] []) $ \(Stack t l r) -> Stack a (t:l) r
-- Old semantics, from Huet.
-- > w { down = a : down w }
@ -381,10 +387,10 @@ insertUp a s = if member a s then s else insert
-- /O(1) on current window, O(n) in general/. Delete window 'w' if it exists.
-- There are 4 cases to consider:
--
-- * delete on an Empty workspace leaves it Empty
-- * delete on an Nothing workspace leaves it Nothing
-- * otherwise, try to move focus to the down
-- * otherwise, try to move focus to the up
-- * otherwise, you've got an empty workspace, becomes Empty
-- * otherwise, you've got an empty workspace, becomes Nothing
--
-- Behaviour with respect to the master:
--
@ -399,13 +405,13 @@ delete w s | Just w == peek s = remove s -- common case.
removeWindow o n = foldr ($) s [view o,remove,view n]
-- actual removal logic, and focus/master logic:
remove = modify Empty $ \c ->
remove = modify Nothing $ \c ->
if focus c == w
then case c of
Node _ ls (r:rs) -> Node r ls rs -- try down first
Node _ (l:ls) [] -> Node l ls [] -- else up
Node _ [] [] -> Empty
else c { up = w `L.delete` up c, down = w `L.delete` down c }
Stack _ ls (r:rs) -> Just $ Stack r ls rs -- try down first
Stack _ (l:ls) [] -> Just $ Stack l ls [] -- else up
Stack _ [] [] -> Nothing
else Just $ c { up = w `L.delete` up c, down = w `L.delete` down c }
------------------------------------------------------------------------
@ -425,9 +431,9 @@ sink w s = s { floating = M.delete w (floating s) }
-- The old master window is swapped in the tiling order with the focused window.
-- Focus stays with the item moved.
swapMaster :: StackSet i a s -> StackSet i a s
swapMaster = modify Empty $ \c -> case c of
Node _ [] _ -> c -- already master.
Node t ls rs -> Node t [] (ys ++ x : rs) where (x:ys) = reverse ls
swapMaster = modify' $ \c -> case c of
Stack _ [] _ -> c -- already master.
Stack t ls rs -> Stack t [] (ys ++ x : rs) where (x:ys) = reverse ls
-- natural! keep focus, move current to the top, move top to current.
--

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@ -16,7 +16,7 @@
module XMonad (
X, WindowSet, WorkspaceId(..), ScreenId(..), XState(..), XConf(..), Layout(..),
Typeable, Message, SomeMessage(..), fromMessage,
Typeable, Message, SomeMessage(..), fromMessage, runLayout,
runX, io, catchIO, withDisplay, withWindowSet, isRoot, spawn, restart, trace, whenJust, whenX,
atom_WM_STATE, atom_WM_PROTOCOLS, atom_WM_DELETE_WINDOW
) where
@ -111,6 +111,9 @@ atom_WM_STATE = getAtom "WM_STATE"
data Layout = Layout { doLayout :: Rectangle -> Stack Window -> X [(Window, Rectangle)]
, modifyLayout :: SomeMessage -> X (Maybe Layout) }
runLayout :: Layout -> Rectangle -> StackOrNot Window -> X [(Window, Rectangle)]
runLayout l r = maybe (return []) (doLayout l r)
-- Based on ideas in /An Extensible Dynamically-Typed Hierarchy of Exceptions/,
-- Simon Marlow, 2006. Use extensible messages to the modifyLayout handler.
--

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@ -114,7 +114,7 @@ invariant (s :: T) = and
where
ws = concat [ focus t : up t ++ down t
| w <- workspace (current s) : map workspace (visible s) ++ hidden s
, let t = stack w, t /= Empty ] :: [Char]
, t <- maybeToList (stack w)] :: [Char]
noDuplicates = nub ws == ws
calculatedSize = length (visible s) + length (hidden s) + 1 -- +1 is for current
accurateSize = calculatedSize == size s
@ -148,7 +148,7 @@ prop_focusDown_I (n :: NonNegative Int) (x :: T) =
prop_focus_I (n :: NonNegative Int) (x :: T) =
case peek x of
Nothing -> True
Just _ -> let w = focus . stack . workspace . current $ foldr (const focusUp) x [1..n]
Just _ -> let w = focus . fromJust . stack . workspace . current $ foldr (const focusUp) x [1..n]
in invariant $ focusWindow w x
prop_insertUp_I n (x :: T) = invariant $ insertUp n x
@ -175,7 +175,7 @@ prop_shift_I (n :: NonNegative Int) (x :: T) =
-- empty StackSets have no windows in them
prop_empty (n :: Positive Int)
(m :: Positive Int) =
all (== Empty) [ stack w | w <- workspace (current x)
all (== Nothing) [ stack w | w <- workspace (current x)
: map workspace (visible x) ++ hidden x ]
where x = new (fromIntegral n) (fromIntegral m) :: T
@ -257,12 +257,9 @@ prop_member_peek (x :: T) =
-- the list returned by index should be the same length as the actual
-- windows kept in the zipper
prop_index_length (x :: T) =
case it of
Empty -> length (index x) == 0
Node {} -> length (index x) == length list
where
it = stack . workspace . current $ x
list = focus it : up it ++ down it
case stack . workspace . current $ x of
Nothing -> length (index x) == 0
Just it -> length (index x) == length (focus it : up it ++ down it)
-- ---------------------------------------------------------------------
-- rotating focus
@ -293,7 +290,7 @@ prop_focusWindow_works (n :: NonNegative Int) (x :: T) =
Nothing -> True
Just _ -> let s = index x
i = fromIntegral n `mod` length s
in (focus . stack . workspace . current) (focusWindow (s !! i) x) == (s !! i)
in (focus . fromJust . stack . workspace . current) (focusWindow (s !! i) x) == (s !! i)
-- rotation through the height of a stack gets us back to the start
prop_focus_all_l (x :: T) = (foldr (const focusUp) x [1..n]) == x
@ -324,9 +321,8 @@ prop_focusWindow_local (n :: NonNegative Int) (x::T ) =
prop_findIndex (x :: T) =
and [ tag w == fromJust (findIndex i x)
| w <- workspace (current x) : map workspace (visible x) ++ hidden x
, let t = stack w
, t /= Empty
, i <- focus (stack w) : up (stack w) ++ down (stack w)
, t <- maybeToList (stack w)
, i <- focus t : up t ++ down t
]
-- ---------------------------------------------------------------------