From f96b482efd7b989403a73c1ede225889009e47dd Mon Sep 17 00:00:00 2001
From: Don Stewart <dons@cse.unsw.edu.au>
Date: Thu, 19 Apr 2007 03:27:05 +0200
Subject: Parameterise StackSet by two index types, rather than breaking
abstraction
darcs-hash:20070419012705-9c5c1-3aa97e02123af08c3f4500c9e9c3bb7ab4121652.gz
---
Operations.hs | 6 ++--
StackSet.hs | 88 ++++++++++++++++++++++++++---------------------------
XMonad.hs | 15 ++++++---
tests/Properties.hs | 6 ++--
4 files changed, 59 insertions(+), 56 deletions(-)
diff --git a/Operations.hs b/Operations.hs
index 0effd8d..48ba9db 100644
--- a/Operations.hs
+++ b/Operations.hs
@@ -240,7 +240,7 @@ kill = withDisplay $ \d -> do
else io (killClient d w) >> return ()
-- | tag. Move a window to a new workspace, 0 indexed.
-tag :: W.WorkspaceId -> X ()
+tag :: WorkspaceId -> X ()
tag n = do
ws <- gets workspace
let m = W.current ws -- :: WorkspaceId
@@ -250,7 +250,7 @@ tag n = do
windows $ W.shift n
-- | view. Change the current workspace to workspace at offset n (0 indexed).
-view :: W.WorkspaceId -> X ()
+view :: WorkspaceId -> X ()
view n = do
ws <- gets workspace
let m = W.current ws
@@ -263,7 +263,7 @@ view n = do
setTopFocus
-- | 'screenWorkspace sc' returns the workspace number viewed by 'sc'.
-screenWorkspace :: W.ScreenId -> X W.WorkspaceId
+screenWorkspace :: ScreenId -> X WorkspaceId
screenWorkspace sc = fmap (fromMaybe 0 . W.workspace sc) (gets workspace)
-- | True if window is under management by us
diff --git a/StackSet.hs b/StackSet.hs
index f0168d1..a212049 100644
--- a/StackSet.hs
+++ b/StackSet.hs
@@ -21,7 +21,13 @@
-- given time.
--
-module StackSet where
+module StackSet (
+ StackSet(..), -- abstract
+
+ screen, peekStack, index, empty, peek, push, delete, member,
+ raiseFocus, rotate, promote, shift, view, workspace, fromList,
+ toList, size, visibleWorkspaces
+ ) where
import Data.Maybe
import qualified Data.List as L (delete,genericLength,elemIndex)
@@ -29,28 +35,21 @@ import qualified Data.Map as M
------------------------------------------------------------------------
--- | The StackSet data structure. A table of stacks, with a current pointer
-data StackSet a =
+-- | The StackSet data structure. Multiple screens containing tables of
+-- stacks, with a current pointer
+data StackSet i j a =
StackSet
- { current :: !WorkspaceId -- ^ the currently visible stack
- , screen2ws:: !(M.Map ScreenId WorkspaceId) -- ^ screen -> workspace
- , ws2screen:: !(M.Map WorkspaceId ScreenId) -- ^ workspace -> screen map
- , stacks :: !(M.Map WorkspaceId [a]) -- ^ the separate stacks
- , focus :: !(M.Map WorkspaceId a) -- ^ the window focused in each stack
- , cache :: !(M.Map a WorkspaceId) -- ^ a cache of windows back to their stacks
+ { current :: !i -- ^ the currently visible stack
+ , screen2ws:: !(M.Map j i) -- ^ screen -> workspace
+ , ws2screen:: !(M.Map i j) -- ^ workspace -> screen map
+ , stacks :: !(M.Map i [a]) -- ^ the separate stacks
+ , 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
--- | Physical screen indicies
-newtype ScreenId = S Int deriving (Eq,Ord,Show,Enum,Num,Integral,Real)
-
--- | Virtual workspace indicies
-newtype WorkspaceId = W Int deriving (Eq,Ord,Show,Enum,Num,Integral,Real)
-
-instance Show a => Show (StackSet a) where
+instance (Show i, Show a) => Show (StackSet i j a) where
showsPrec p s r = showsPrec p (show . toList $ s) r
--- Ord a constraint on 'a' as we use it as a key.
---
-- The cache is used to check on insertion that we don't already have
-- this window managed on another stack
@@ -58,29 +57,28 @@ instance Show a => Show (StackSet a) where
-- | /O(n)/. Create a new empty stacks of size 'n', indexed from 0, with 'm'
-- screens. (also indexed from 0) The 0-indexed stack will be current.
-empty :: Int -> Int -> StackSet a
+empty :: (Integral i, Integral j) => Int -> Int -> StackSet i j a
empty n m = StackSet { current = 0
, screen2ws = wsScrs2Works
-
, ws2screen = wsWorks2Scrs
- , stacks = M.fromList (zip [0..W n-1] (repeat []))
+ , stacks = M.fromList (zip [0..fromIntegral n-1] (repeat []))
, focus = M.empty
, cache = M.empty }
- where (scrs,wrks) = unzip $ map (\x -> (S x, W x)) [0..m-1]
+ where (scrs,wrks) = unzip $ map (\x -> (fromIntegral x, fromIntegral x)) [0..m-1]
wsScrs2Works = M.fromList (zip scrs wrks)
wsWorks2Scrs = M.fromList (zip wrks scrs)
-- | /O(log w)/. True if x is somewhere in the StackSet
-member :: Ord a => a -> StackSet a -> Bool
+member :: Ord a => a -> StackSet i j a -> Bool
member a w = M.member a (cache w)
-- | /O(log n)/. Looks up the workspace that x is in, if it is in the StackSet
-lookup :: (Monad m, Ord a) => a -> StackSet a -> m WorkspaceId
-lookup x w = M.lookup x (cache w)
+-- lookup :: (Monad m, Ord a) => a -> StackSet i j a -> m i
+-- lookup x w = M.lookup x (cache w)
-- | /O(n)/. Number of stacks
-size :: StackSet a -> Int
+size :: StackSet i j a -> Int
size = M.size . stacks
------------------------------------------------------------------------
@@ -89,7 +87,7 @@ size = M.size . stacks
-- keeping track of the currently focused workspace, and the total
-- number of workspaces. If there are duplicates in the list, the last
-- occurence wins.
-fromList :: Ord a => (WorkspaceId, Int,[[a]]) -> StackSet a
+fromList :: (Integral i, Integral j, Ord a) => (i, Int,[[a]]) -> StackSet i j a
fromList (_,_,[]) = error "Cannot build a StackSet from an empty list"
fromList (n,m,xs) | n < 0 || n >= L.genericLength xs
@@ -103,36 +101,36 @@ fromList (o,m,xs) = view o $ foldr (\(i,ys) s ->
-- | toList. Flatten a stackset to a list of lists
-toList :: StackSet a -> (WorkspaceId,Int,[[a]])
+toList :: StackSet i j a -> (i,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.
-- If the element is managed on another stack, it is removed from that
-- stack first.
-push :: Ord a => a -> StackSet a -> StackSet a
+push :: (Integral i, Ord a) => a -> StackSet i j a -> StackSet i j a
push k w = insert k (current w) w
-- | /O(log s)/. Extract the element on the top of the current stack. If no such
-- element exists, Nothing is returned.
-peek :: StackSet a -> Maybe a
+peek :: Integral i => StackSet i j a -> Maybe a
peek w = peekStack (current w) w
-- | /O(log s)/. Extract the element on the top of the given stack. If no such
-- element exists, Nothing is returned.
-peekStack :: WorkspaceId -> StackSet a -> Maybe a
-peekStack n w = M.lookup n (focus w)
+peekStack :: Integral i => i -> StackSet i j a -> Maybe a
+peekStack i w = M.lookup i (focus w)
--- | /O(log s)/. Index. Extract the stack at index 'n'.
+-- | /O(log s)/. Index. Extract the stack at workspace 'n'.
-- If the index is invalid, an exception is thrown.
-index :: WorkspaceId -> StackSet a -> [a]
+index :: Integral i => i -> StackSet i j a -> [a]
index k w = fromJust (M.lookup k (stacks w))
-- | view. Set the stack specified by the argument as being visible and the
-- current StackSet. If the stack wasn't previously visible, it will become
-- visible on the current screen. If the index is out of range an exception is
-- thrown.
-view :: WorkspaceId -> StackSet a -> StackSet a
+view :: (Integral i, Integral j) => i -> StackSet i j a -> StackSet i j a
-- view n w | n >= 0 && n < fromIntegral (M.size (stacks w)) -- coerce
view n w | M.member n (stacks w)
@@ -146,15 +144,15 @@ view n w | M.member n (stacks w)
}
-- | That screen that workspace 'n' is visible on, if any.
-screen :: WorkspaceId -> StackSet a -> Maybe ScreenId
+screen :: Integral i => i -> StackSet i j a -> Maybe j
screen n w = M.lookup n (ws2screen w)
-- | The workspace visible on screen 'sc'. Nothing if screen is out of bounds.
-workspace :: ScreenId -> StackSet a -> Maybe WorkspaceId
+workspace :: Integral j => j -> StackSet i j a -> Maybe i
workspace sc w = M.lookup sc (screen2ws w)
-- | A list of the currently visible workspaces.
-visibleWorkspaces :: StackSet a -> [WorkspaceId]
+visibleWorkspaces :: StackSet i j a -> [i]
visibleWorkspaces = M.keys . ws2screen
--
@@ -168,7 +166,7 @@ visibleWorkspaces = M.keys . ws2screen
--
-- where xs = [5..8] ++ [1..4]
--
-rotate :: Eq a => Ordering -> StackSet a -> StackSet a
+rotate :: (Integral i, Eq a) => Ordering -> StackSet i j a -> StackSet i j a
rotate o w = maybe w id $ do
f <- M.lookup (current w) (focus w)
s <- M.lookup (current w) (stacks w)
@@ -182,7 +180,7 @@ rotate o w = maybe w id $ do
-- the top of stack 'n'. If the stack to move to is not valid, and
-- exception is thrown.
--
-shift :: Ord a => WorkspaceId -> StackSet a -> StackSet a
+shift :: (Integral i, Ord a) => i -> StackSet i j a -> StackSet i j a
shift n w = maybe w (\k -> insert k n (delete k w)) (peek w)
-- | /O(log n)/. Insert an element onto the top of stack 'n'.
@@ -190,7 +188,7 @@ shift n w = maybe w (\k -> insert k n (delete k w)) (peek w)
-- If the element exists on another stack, it is removed from that stack.
-- If the index is wrong an exception is thrown.
--
-insert :: Ord a => a -> WorkspaceId -> StackSet a -> StackSet a
+insert :: (Integral i, Ord a) => a -> i -> StackSet i j a -> StackSet i j a
insert k n old = new { cache = M.insert k n (cache new)
, stacks = M.adjust (k:) n (stacks new)
, focus = M.insert n k (focus new) }
@@ -199,7 +197,7 @@ insert k n old = new { cache = M.insert k n (cache new)
-- | /O(log n)/. Delete an element entirely from from the StackSet.
-- This can be used to ensure that a given element is not managed elsewhere.
-- If the element doesn't exist, the original StackSet is returned unmodified.
-delete :: Ord a => a -> StackSet a -> StackSet a
+delete :: (Integral i, Ord a) => a -> StackSet i j a -> StackSet i j a
delete k w = maybe w tweak (M.lookup k (cache w))
where
tweak i = w { cache = M.delete k (cache w)
@@ -211,14 +209,14 @@ delete k w = maybe w tweak (M.lookup k (cache w))
-- | /O(log n)/. If the given window is contained in a workspace, make it the
-- focused window of that workspace, and make that workspace the current one.
-raiseFocus :: Ord a => a -> StackSet a -> StackSet a
+raiseFocus :: (Integral i, Integral j, Ord a) => a -> StackSet i j a -> StackSet i j a
raiseFocus k w = case M.lookup k (cache w) of
Nothing -> w
Just i -> (view i w) { focus = M.insert i k (focus w) }
-- | Swap the currently focused window with the master window (the
-- window on top of the stack). Focus moves to the master.
-promote :: Ord a => StackSet a -> StackSet a
+promote :: (Integral i, Ord a) => StackSet i j a -> StackSet i j a
promote w = maybe w id $ do
a <- peek w -- fail if null
let w' = w { stacks = M.adjust (\s -> swap a (head s) s) (current w) (stacks w) }
@@ -246,6 +244,6 @@ swap _ _ xs = xs -- do nothing
-- next xs = last xs : init xs
--
--- |
+-- | Find the element in the (circular) list after given element.
elemAfter :: Eq a => a -> [a] -> Maybe a
elemAfter w ws = listToMaybe . filter (/= w) . dropWhile (/= w) $ ws ++ ws
diff --git a/XMonad.hs b/XMonad.hs
index 0de51ed..9053e69 100644
--- a/XMonad.hs
+++ b/XMonad.hs
@@ -15,12 +15,11 @@
--
module XMonad (
- X, WorkSpace, XState(..), Layout(..), LayoutDesc(..),
- runX, io, withDisplay, isRoot,
- spawn, trace, whenJust, rotateLayout
+ X, WorkSpace, WorkspaceId(..), ScreenId(..), XState(..), Layout(..), LayoutDesc(..),
+ runX, io, withDisplay, isRoot, spawn, trace, whenJust, rotateLayout
) where
-import StackSet (StackSet,WorkspaceId)
+import StackSet (StackSet)
import Control.Monad.State
import System.IO
@@ -48,7 +47,13 @@ data XState = XState
-- to descriptions of their layouts
}
-type WorkSpace = StackSet Window
+type WorkSpace = StackSet WorkspaceId ScreenId Window
+
+-- | Virtual workspace indicies
+newtype WorkspaceId = W Int deriving (Eq,Ord,Show,Enum,Num,Integral,Real)
+
+-- | Physical screen indicies
+newtype ScreenId = S Int deriving (Eq,Ord,Show,Enum,Num,Integral,Real)
------------------------------------------------------------------------
diff --git a/tests/Properties.hs b/tests/Properties.hs
index e69c7f9..7eefe67 100644
--- a/tests/Properties.hs
+++ b/tests/Properties.hs
@@ -17,11 +17,11 @@ import Data.Map (keys,elems)
-- QuickCheck properties for the StackSet
-- | Height of stack 'n'
-height :: WorkspaceId -> StackSet a -> Int
+height :: Int -> T -> Int
height i w = length (index i w)
-- build (non-empty) StackSets with between 1 and 100 stacks
-instance (Ord a, Arbitrary a) => Arbitrary (StackSet a) where
+instance (Integral i, Integral j, Ord a, Arbitrary a) => Arbitrary (StackSet i j a) where
arbitrary = do
sz <- choose (1,20)
n <- choose (0,sz-1)
@@ -58,7 +58,7 @@ prop_peekmember x = case peek x of
Nothing -> True {- then we don't know anything -}
where _ = x :: T
-type T = StackSet Int
+type T = StackSet Int Int Int
prop_delete_uniq i x = not (member i x) ==> delete i x == x
where _ = x :: T
--
cgit v1.2.3