    --------------------------------------------------------------------
    -- |
    -- Module      :  XMonad.Util.EZConfig
    -- Copyright   :  Devin Mullins <me@twifkak.com>
    --                Brent Yorgey <byorgey@gmail.com> (key parsing)
    -- License     :  BSD3-style (see LICENSE)
    --
    -- Maintainer  :  Devin Mullins <me@twifkak.com>
    --
    -- Useful helper functions for amending the defaultConfig, and for
    -- parsing keybindings specified in a special (emacs-like) format.
    --
    -- (See also "XMonad.Util.CustomKeys" in xmonad-contrib.)
    --
    --------------------------------------------------------------------

    module XMonad.Util.EZConfig (
                                 -- * Usage
                                 -- $usage

                                 -- * Adding or removing keybindings

                                 additionalKeys, additionalKeysP,
                                 removeKeys, removeKeysP,
                                 additionalMouseBindings, removeMouseBindings,

                                 -- * Emacs-style keybinding specifications

                                 mkKeymap, checkKeymap,
                                 mkNamedKeymap,

                                 parseKey -- used by XMonad.Util.Paste
                                ) where

    import XMonad
    import XMonad.Actions.Submap

    import XMonad.Util.NamedActions

    import qualified Data.Map as M
    import Data.List (foldl', sortBy, groupBy, nub)
    import Data.Ord (comparing)
    import Data.Maybe
    import Control.Arrow (first, (&&&))

    import Text.ParserCombinators.ReadP

    -- $usage
    -- To use this module, first import it into your @~\/.xmonad\/xmonad.hs@:
    --
    -- > import XMonad.Util.EZConfig
    --
    -- Then, use one of the provided functions to modify your
    -- configuration.  You can use 'additionalKeys', 'removeKeys',
    -- 'additionalMouseBindings', and 'removeMouseBindings' to easily add
    -- and remove keybindings or mouse bindings.  You can use 'mkKeymap'
    -- to create a keymap using emacs-style keybinding specifications
    -- like @\"M-x\"@ instead of @(modMask, xK_x)@, or 'additionalKeysP'
    -- and 'removeKeysP' to easily add or remove emacs-style keybindings.
    -- If you use emacs-style keybindings, the 'checkKeymap' function is
    -- provided, suitable for adding to your 'startupHook', which can warn
    -- you of any parse errors or duplicate bindings in your keymap.
    --
    -- For more information and usage examples, see the documentation
    -- provided with each exported function, and check the xmonad config
    -- archive (<http://haskell.org/haskellwiki/Xmonad/Config_archive>)
    -- for some real examples of use.

    -- |
    -- Add or override keybindings from the existing set. Example use:
    --
    -- > main = xmonad $ defaultConfig { terminal = "urxvt" }
    -- >                 `additionalKeys`
    -- >                 [ ((mod1Mask, xK_m        ), spawn "echo 'Hi, mom!' | dzen2 -p 4")
    -- >                 , ((mod1Mask, xK_BackSpace), withFocused hide) -- N.B. this is an absurd thing to do
    -- >                 ]
    --
    -- This overrides the previous definition of mod-m.
    --
    -- Note that, unlike in xmonad 0.4 and previous, you can't use modMask to refer
    -- to the modMask you configured earlier. You must specify mod1Mask (or
    -- whichever), or add your own @myModMask = mod1Mask@ line.
    additionalKeys :: XConfig a -> [((ButtonMask, KeySym), X ())] -> XConfig a
    additionalKeys conf keyList =
        conf { keys = \cnf -> M.union (M.fromList keyList) (keys conf cnf) }

    -- | Like 'additionalKeys', except using short @String@ key
    --   descriptors like @\"M-m\"@ instead of @(modMask, xK_m)@, as
    --   described in the documentation for 'mkKeymap'.  For example:
    --
    -- > main = xmonad $ defaultConfig { terminal = "urxvt" }
    -- >                 `additionalKeysP`
    -- >                 [ ("M-m", spawn "echo 'Hi, mom!' | dzen2 -p 4")
    -- >                 , ("M-<Backspace>", withFocused hide) -- N.B. this is an absurd thing to do
    -- >                 ]

    additionalKeysP :: XConfig l -> [(String, X ())] -> XConfig l
    additionalKeysP conf keyList =
        conf { keys = \cnf -> M.union (mkKeymap cnf keyList) (keys conf cnf) }

    -- |
    -- Remove standard keybindings you're not using. Example use:
    --
    -- > main = xmonad $ defaultConfig { terminal = "urxvt" }
    -- >                 `removeKeys` [(mod1Mask .|. shiftMask, n) | n <- [xK_1 .. xK_9]]
    removeKeys :: XConfig a -> [(ButtonMask, KeySym)] -> XConfig a
    removeKeys conf keyList =
        conf { keys = \cnf -> keys conf cnf `M.difference` M.fromList (zip keyList $ repeat ()) }

    -- | Like 'removeKeys', except using short @String@ key descriptors
    --   like @\"M-m\"@ instead of @(modMask, xK_m)@, as described in the
    --   documentation for 'mkKeymap'. For example:
    --
    -- > main = xmonad $ defaultConfig { terminal = "urxvt" }
    -- >                 `removeKeysP` ["M-S-" ++ [n] | n <- ['1'..'9']]

    removeKeysP :: XConfig l -> [String] -> XConfig l
    removeKeysP conf keyList =
        conf { keys = \cnf -> keys conf cnf `M.difference` mkKeymap cnf (zip keyList $ repeat (return ())) }

    -- | Like 'additionalKeys', but for mouse bindings.
    additionalMouseBindings :: XConfig a -> [((ButtonMask, Button), Window -> X ())] -> XConfig a
    additionalMouseBindings conf mouseBindingsList =
        conf { mouseBindings = \cnf -> M.union (M.fromList mouseBindingsList) (mouseBindings conf cnf) }

    -- | Like 'removeKeys', but for mouse bindings.
    removeMouseBindings :: XConfig a -> [(ButtonMask, Button)] -> XConfig a
    removeMouseBindings conf mouseBindingList =
        conf { mouseBindings = \cnf -> mouseBindings conf cnf `M.difference`
                                       M.fromList (zip mouseBindingList $ repeat ()) }

    --------------------------------------------------------------
    --  Keybinding parsing  ---------------------------------------
    --------------------------------------------------------------

    -- | Given a config (used to determine the proper modifier key to use)
    --   and a list of @(String, X ())@ pairs, create a key map by parsing
    --   the key sequence descriptions contained in the Strings.  The key
    --   sequence descriptions are \"emacs-style\": @M-@, @C-@, @S-@, and
    --   @M\#-@ denote mod, control, shift, and mod1-mod5 (where @\#@ is
    --   replaced by the appropriate number) respectively.  Note that if
    --   you want to make a keybinding using \'alt\' even though you use a
    --   different key (like the \'windows\' key) for \'mod\', you can use
    --   something like @\"M1-x\"@ for alt+x (check the output of @xmodmap@
    --   to see which mod key \'alt\' is bound to). Some special keys can
    --   also be specified by enclosing their name in angle brackets.
    --
    --   For example, @\"M-C-x\"@ denotes mod+ctrl+x; @\"S-\<Escape\>\"@
    --   denotes shift-escape; @\"M1-C-\<Delete\>\"@ denotes alt+ctrl+delete
    --   (assuming alt is bound to mod1, which is common).
    --
    --   Sequences of keys can also be specified by separating the key
    --   descriptions with spaces. For example, @\"M-x y \<Down\>\"@ denotes the
    --   sequence of keys mod+x, y, down.  Submaps (see
    --   "XMonad.Actions.Submap") will be automatically generated to
    --   correctly handle these cases.
    --
    --   So, for example, a complete key map might be specified as
    --
    -- > keys = \c -> mkKeymap c $
    -- >     [ ("M-S-<Return>", spawn $ terminal c)
    -- >     , ("M-x w", spawn "xmessage 'woohoo!'")  -- type mod+x then w to pop up 'woohoo!'
    -- >     , ("M-x y", spawn "xmessage 'yay!'")     -- type mod+x then y to pop up 'yay!'
    -- >     , ("M-S-c", kill)
    -- >     ]
    --
    -- Alternatively, you can use 'additionalKeysP' to automatically
    -- create a keymap and add it to your config.
    --
    -- Here is a complete list of supported special keys.  Note that a few
    -- keys, such as the arrow keys, have synonyms.  If there are other
    -- special keys you would like to see supported, feel free to submit a
    -- patch, or ask on the xmonad mailing list; adding special keys is
    -- quite simple.
    --
    -- > <Backspace>
    -- > <Tab>
    -- > <Return>
    -- > <Pause>
    -- > <Scroll_lock>
    -- > <Sys_Req>
    -- > <Print>
    -- > <Escape>, <Esc>
    -- > <Delete>
    -- > <Home>
    -- > <Left>, <L>
    -- > <Up>, <U>
    -- > <Right>, <R>
    -- > <Down>, <D>
    -- > <Page_Up>
    -- > <Page_Down>
    -- > <End>
    -- > <Insert>
    -- > <Break>
    -- > <Space>
    -- > <F1>-<F24>
    -- > <KP_Space>
    -- > <KP_Tab>
    -- > <KP_Enter>
    -- > <KP_F1>
    -- > <KP_F2>
    -- > <KP_F3>
    -- > <KP_F4>
    -- > <KP_Home>
    -- > <KP_Left>
    -- > <KP_Up>
    -- > <KP_Right>
    -- > <KP_Down>
    -- > <KP_Prior>
    -- > <KP_Page_Up>
    -- > <KP_Next>
    -- > <KP_Page_Down>
    -- > <KP_End>
    -- > <KP_Begin>
    -- > <KP_Insert>
    -- > <KP_Delete>
    -- > <KP_Equal>
    -- > <KP_Multiply>
    -- > <KP_Add>
    -- > <KP_Separator>
    -- > <KP_Subtract>
    -- > <KP_Decimal>
    -- > <KP_Divide>
    -- > <KP_0>-<KP_9>
    --
    -- Long list of multimedia keys. Please note that not all keys may be
    -- present in your particular setup although most likely they will do.
    --
    -- > <XF86ModeLock>
    -- > <XF86MonBrightnessUp>
    -- > <XF86MonBrightnessDown>
    -- > <XF86KbdLightOnOff>
    -- > <XF86KbdBrightnessUp>
    -- > <XF86KbdBrightnessDown>
    -- > <XF86Standby>
    -- > <XF86AudioLowerVolume>
    -- > <XF86AudioMute>
    -- > <XF86AudioRaiseVolume>
    -- > <XF86AudioPlay>
    -- > <XF86AudioStop>
    -- > <XF86AudioPrev>
    -- > <XF86AudioNext>
    -- > <XF86HomePage>
    -- > <XF86Mail>
    -- > <XF86Start>
    -- > <XF86Search>
    -- > <XF86AudioRecord>
    -- > <XF86Calculator>
    -- > <XF86Memo>
    -- > <XF86ToDoList>
    -- > <XF86Calendar>
    -- > <XF86PowerDown>
    -- > <XF86ContrastAdjust>
    -- > <XF86RockerUp>
    -- > <XF86RockerDown>
    -- > <XF86RockerEnter>
    -- > <XF86Back>
    -- > <XF86Forward>
    -- > <XF86Stop>
    -- > <XF86Refresh>
    -- > <XF86PowerOff>
    -- > <XF86WakeUp>
    -- > <XF86Eject>
    -- > <XF86ScreenSaver>
    -- > <XF86WWW>
    -- > <XF86Sleep>
    -- > <XF86Favorites>
    -- > <XF86AudioPause>
    -- > <XF86AudioMedia>
    -- > <XF86MyComputer>
    -- > <XF86VendorHome>
    -- > <XF86LightBulb>
    -- > <XF86Shop>
    -- > <XF86History>
    -- > <XF86OpenURL>
    -- > <XF86AddFavorite>
    -- > <XF86HotLinks>
    -- > <XF86BrightnessAdjust>
    -- > <XF86Finance>
    -- > <XF86Community>
    -- > <XF86AudioRewind>
    -- > <XF86XF86BackForward>
    -- > <XF86Launch0>-<XF86Launch9>, <XF86LaunchA>-<XF86LaunchF>
    -- > <XF86ApplicationLeft>
    -- > <XF86ApplicationRight>
    -- > <XF86Book>
    -- > <XF86CD>
    -- > <XF86Calculater>
    -- > <XF86Clear>
    -- > <XF86Close>
    -- > <XF86Copy>
    -- > <XF86Cut>
    -- > <XF86Display>
    -- > <XF86DOS>
    -- > <XF86Documents>
    -- > <XF86Excel>
    -- > <XF86Explorer>
    -- > <XF86Game>
    -- > <XF86Go>
    -- > <XF86iTouch>
    -- > <XF86LogOff>
    -- > <XF86Market>
    -- > <XF86Meeting>
    -- > <XF86MenuKB>
    -- > <XF86MenuPB>
    -- > <XF86MySites>
    -- > <XF86New>
    -- > <XF86News>
    -- > <XF86OfficeHome>
    -- > <XF86Open>
    -- > <XF86Option>
    -- > <XF86Paste>
    -- > <XF86Phone>
    -- > <XF86Q>
    -- > <XF86Reply>
    -- > <XF86Reload>
    -- > <XF86RotateWindows>
    -- > <XF86RotationPB>
    -- > <XF86RotationKB>
    -- > <XF86Save>
    -- > <XF86ScrollUp>
    -- > <XF86ScrollDown>
    -- > <XF86ScrollClick>
    -- > <XF86Send>
    -- > <XF86Spell>
    -- > <XF86SplitScreen>
    -- > <XF86Support>
    -- > <XF86TaskPane>
    -- > <XF86Terminal>
    -- > <XF86Tools>
    -- > <XF86Travel>
    -- > <XF86UserPB>
    -- > <XF86User1KB>
    -- > <XF86User2KB>
    -- > <XF86Video>
    -- > <XF86WheelButton>
    -- > <XF86Word>
    -- > <XF86Xfer>
    -- > <XF86ZoomIn>
    -- > <XF86ZoomOut>
    -- > <XF86Away>
    -- > <XF86Messenger>
    -- > <XF86WebCam>
    -- > <XF86MailForward>
    -- > <XF86Pictures>
    -- > <XF86Music>
    -- > <XF86TouchpadToggle>
    -- > <XF86_Switch_VT_1>-<XF86_Switch_VT_12>
    -- > <XF86_Ungrab>
    -- > <XF86_ClearGrab>
    -- > <XF86_Next_VMode>
    -- > <XF86_Prev_VMode>

    mkKeymap :: XConfig l -> [(String, X ())] -> M.Map (KeyMask, KeySym) (X ())
    mkKeymap c = M.fromList . mkSubmaps . readKeymap c

    mkNamedKeymap :: XConfig l -> [(String, NamedAction)] -> [((KeyMask, KeySym), NamedAction)]
    mkNamedKeymap c = mkNamedSubmaps . readKeymap c

    -- | Given a list of pairs of parsed key sequences and actions,
    --   group them into submaps in the appropriate way.

    mkNamedSubmaps :: [([(KeyMask, KeySym)], NamedAction)] -> [((KeyMask, KeySym), NamedAction)]
    mkNamedSubmaps = mkSubmaps' submapName

    mkSubmaps :: [ ([(KeyMask,KeySym)], X ()) ] -> [((KeyMask, KeySym), X ())]
    mkSubmaps = mkSubmaps' $ submap . M.fromList

    mkSubmaps' ::  (Ord a) => ([(a, c)] -> c) -> [([a], c)] -> [(a, c)]
    mkSubmaps' subm binds = map combine gathered
      where gathered = groupBy fstKey
                     . sortBy (comparing fst)
                     $ binds
            combine [([k],act)] = (k,act)
            combine ks = (head . fst . head $ ks,
                          subm . mkSubmaps' subm $ map (first tail) ks)
            fstKey = (==) `on` (head . fst)

    on :: (a -> a -> b) -> (c -> a) -> c -> c -> b
    op `on` f = \x y -> f x `op` f y

    -- | Given a configuration record and a list of (key sequence
    --   description, action) pairs, parse the key sequences into lists of
    --   @(KeyMask,KeySym)@ pairs.  Key sequences which fail to parse will
    --   be ignored.
    readKeymap :: XConfig l -> [(String, t)] -> [([(KeyMask, KeySym)], t)]
    readKeymap c = mapMaybe (maybeKeys . first (readKeySequence c))
      where maybeKeys (Nothing,_) = Nothing
            maybeKeys (Just k, act) = Just (k, act)

    -- | Parse a sequence of keys, returning Nothing if there is
    --   a parse failure (no parse, or ambiguous parse).
    readKeySequence :: XConfig l -> String -> Maybe [(KeyMask, KeySym)]
    readKeySequence c = listToMaybe . parses
      where parses = map fst . filter (null.snd) . readP_to_S (parseKeySequence c)

    -- | Parse a sequence of key combinations separated by spaces, e.g.
    --   @\"M-c x C-S-2\"@ (mod+c, x, ctrl+shift+2).
    parseKeySequence :: XConfig l -> ReadP [(KeyMask, KeySym)]
    parseKeySequence c = sepBy1 (parseKeyCombo c) (many1 $ char ' ')

    -- | Parse a modifier-key combination such as "M-C-s" (mod+ctrl+s).
    parseKeyCombo :: XConfig l -> ReadP (KeyMask, KeySym)
    parseKeyCombo c = do mods <- many (parseModifier c)
                         k <- parseKey
                         return (foldl' (.|.) 0 mods, k)

    -- | Parse a modifier: either M- (user-defined mod-key),
    --   C- (control), S- (shift), or M#- where # is an integer
    --   from 1 to 5 (mod1Mask through mod5Mask).
    parseModifier :: XConfig l -> ReadP KeyMask
    parseModifier c =  (string "M-" >> return (modMask c))
                   +++ (string "C-" >> return controlMask)
                   +++ (string "S-" >> return shiftMask)
                   +++ do _ <- char 'M'
                          n <- satisfy (`elem` ['1'..'5'])
                          _ <- char '-'
                          return $ indexMod (read [n] - 1)
        where indexMod = (!!) [mod1Mask,mod2Mask,mod3Mask,mod4Mask,mod5Mask]

    -- | Parse an unmodified basic key, like @\"x\"@, @\"<F1>\"@, etc.
    parseKey :: ReadP KeySym
    parseKey = parseRegular +++ parseSpecial

    -- | Parse a regular key name (represented by itself).
    parseRegular :: ReadP KeySym
    parseRegular = choice [ char s >> return k
                          | (s,k) <- zip ['!'..'~'] [xK_exclam..xK_asciitilde]
                          ]

    -- | Parse a special key name (one enclosed in angle brackets).
    parseSpecial :: ReadP KeySym
    parseSpecial = do _   <- char '<'
                      key <- choice [ string name >> return k
                                    | (name,k) <- keyNames
                                    ]
                      _   <- char '>'
                      return key

    -- | A list of all special key names and their associated KeySyms.
    keyNames :: [(String, KeySym)]
    keyNames = functionKeys ++ specialKeys ++ multimediaKeys

    -- | A list pairing function key descriptor strings (e.g. @\"<F2>\"@) with
    --   the associated KeySyms.
    functionKeys :: [(String, KeySym)]
    functionKeys = [ ('F' : show n, k)
                   | (n,k) <- zip ([1..24] :: [Int]) [xK_F1..] ]

    -- | A list of special key names and their corresponding KeySyms.
    specialKeys :: [(String, KeySym)]
    specialKeys = [ ("Backspace"  , xK_BackSpace)
                  , ("Tab"        , xK_Tab)
                  , ("Return"     , xK_Return)
                  , ("Pause"      , xK_Pause)
                  , ("Scroll_lock", xK_Scroll_Lock)
                  , ("Sys_Req"    , xK_Sys_Req)
                  , ("Print"      , xK_Print)
                  , ("Escape"     , xK_Escape)
                  , ("Esc"        , xK_Escape)
                  , ("Delete"     , xK_Delete)
                  , ("Home"       , xK_Home)
                  , ("Left"       , xK_Left)
                  , ("Up"         , xK_Up)
                  , ("Right"      , xK_Right)
                  , ("Down"       , xK_Down)
                  , ("L"          , xK_Left)
                  , ("U"          , xK_Up)
                  , ("R"          , xK_Right)
                  , ("D"          , xK_Down)
                  , ("Page_Up"    , xK_Page_Up)
                  , ("Page_Down"  , xK_Page_Down)
                  , ("End"        , xK_End)
                  , ("Insert"     , xK_Insert)
                  , ("Break"      , xK_Break)
                  , ("Space"      , xK_space)
                  , ("KP_Space"   , xK_KP_Space)
                  , ("KP_Tab"     , xK_KP_Tab)
                  , ("KP_Enter"   , xK_KP_Enter)
                  , ("KP_F1"      , xK_KP_F1)
                  , ("KP_F2"      , xK_KP_F2)
                  , ("KP_F3"      , xK_KP_F3)
                  , ("KP_F4"      , xK_KP_F4)
                  , ("KP_Home"    , xK_KP_Home)
                  , ("KP_Left"    , xK_KP_Left)
                  , ("KP_Up"      , xK_KP_Up)
                  , ("KP_Right"   , xK_KP_Right)
                  , ("KP_Down"    , xK_KP_Down)
                  , ("KP_Prior"   , xK_KP_Prior)
                  , ("KP_Page_Up" , xK_KP_Page_Up)
                  , ("KP_Next"    , xK_KP_Next)
                  , ("KP_Page_Down", xK_KP_Page_Down)
                  , ("KP_End"     , xK_KP_End)
                  , ("KP_Begin"   , xK_KP_Begin)
                  , ("KP_Insert"  , xK_KP_Insert)
                  , ("KP_Delete"  , xK_KP_Delete)
                  , ("KP_Equal"   , xK_KP_Equal)
                  , ("KP_Multiply", xK_KP_Multiply)
                  , ("KP_Add"     , xK_KP_Add)
                  , ("KP_Separator", xK_KP_Separator)
                  , ("KP_Subtract", xK_KP_Subtract)
                  , ("KP_Decimal" , xK_KP_Decimal)
                  , ("KP_Divide"  , xK_KP_Divide)
                  , ("KP_0"       , xK_KP_0)
                  , ("KP_1"       , xK_KP_1)
                  , ("KP_2"       , xK_KP_2)
                  , ("KP_3"       , xK_KP_3)
                  , ("KP_4"       , xK_KP_4)
                  , ("KP_5"       , xK_KP_5)
                  , ("KP_6"       , xK_KP_6)
                  , ("KP_7"       , xK_KP_7)
                  , ("KP_8"       , xK_KP_8)
                  , ("KP_9"       , xK_KP_9)
                  ]

    -- | List of multimedia keys. If X server does not know about some
    -- | keysym it's omitted from list. (stringToKeysym returns noSymbol in this case)
    multimediaKeys :: [(String, KeySym)]
    multimediaKeys = filter ((/= noSymbol) . snd) . map (id &&& stringToKeysym) $
                     [ "XF86ModeLock"
                     , "XF86MonBrightnessUp"
                     , "XF86MonBrightnessDown"
                     , "XF86KbdLightOnOff"
                     , "XF86KbdBrightnessUp"
                     , "XF86KbdBrightnessDown"
                     , "XF86Standby"
                     , "XF86AudioLowerVolume"
                     , "XF86AudioMute"
                     , "XF86AudioRaiseVolume"
                     , "XF86AudioPlay"
                     , "XF86AudioStop"
                     , "XF86AudioPrev"
                     , "XF86AudioNext"
                     , "XF86HomePage"
                     , "XF86Mail"
                     , "XF86Start"
                     , "XF86Search"
                     , "XF86AudioRecord"
                     , "XF86Calculator"
                     , "XF86Memo"
                     , "XF86ToDoList"
                     , "XF86Calendar"
                     , "XF86PowerDown"
                     , "XF86ContrastAdjust"
                     , "XF86RockerUp"
                     , "XF86RockerDown"
                     , "XF86RockerEnter"
                     , "XF86Back"
                     , "XF86Forward"
                     , "XF86Stop"
                     , "XF86Refresh"
                     , "XF86PowerOff"
                     , "XF86WakeUp"
                     , "XF86Eject"
                     , "XF86ScreenSaver"
                     , "XF86WWW"
                     , "XF86Sleep"
                     , "XF86Favorites"
                     , "XF86AudioPause"
                     , "XF86AudioMedia"
                     , "XF86MyComputer"
                     , "XF86VendorHome"
                     , "XF86LightBulb"
                     , "XF86Shop"
                     , "XF86History"
                     , "XF86OpenURL"
                     , "XF86AddFavorite"
                     , "XF86HotLinks"
                     , "XF86BrightnessAdjust"
                     , "XF86Finance"
                     , "XF86Community"
                     , "XF86AudioRewind"
                     , "XF86BackForward"
                     , "XF86Launch0"
                     , "XF86Launch1"
                     , "XF86Launch2"
                     , "XF86Launch3"
                     , "XF86Launch4"
                     , "XF86Launch5"
                     , "XF86Launch6"
                     , "XF86Launch7"
                     , "XF86Launch8"
                     , "XF86Launch9"
                     , "XF86LaunchA"
                     , "XF86LaunchB"
                     , "XF86LaunchC"
                     , "XF86LaunchD"
                     , "XF86LaunchE"
                     , "XF86LaunchF"
                     , "XF86ApplicationLeft"
                     , "XF86ApplicationRight"
                     , "XF86Book"
                     , "XF86CD"
                     , "XF86Calculater"
                     , "XF86Clear"
                     , "XF86Close"
                     , "XF86Copy"
                     , "XF86Cut"
                     , "XF86Display"
                     , "XF86DOS"
                     , "XF86Documents"
                     , "XF86Excel"
                     , "XF86Explorer"
                     , "XF86Game"
                     , "XF86Go"
                     , "XF86iTouch"
                     , "XF86LogOff"
                     , "XF86Market"
                     , "XF86Meeting"
                     , "XF86MenuKB"
                     , "XF86MenuPB"
                     , "XF86MySites"
                     , "XF86New"
                     , "XF86News"
                     , "XF86OfficeHome"
                     , "XF86Open"
                     , "XF86Option"
                     , "XF86Paste"
                     , "XF86Phone"
                     , "XF86Q"
                     , "XF86Reply"
                     , "XF86Reload"
                     , "XF86RotateWindows"
                     , "XF86RotationPB"
                     , "XF86RotationKB"
                     , "XF86Save"
                     , "XF86ScrollUp"
                     , "XF86ScrollDown"
                     , "XF86ScrollClick"
                     , "XF86Send"
                     , "XF86Spell"
                     , "XF86SplitScreen"
                     , "XF86Support"
                     , "XF86TaskPane"
                     , "XF86Terminal"
                     , "XF86Tools"
                     , "XF86Travel"
                     , "XF86UserPB"
                     , "XF86User1KB"
                     , "XF86User2KB"
                     , "XF86Video"
                     , "XF86WheelButton"
                     , "XF86Word"
                     , "XF86Xfer"
                     , "XF86ZoomIn"
                     , "XF86ZoomOut"
                     , "XF86Away"
                     , "XF86Messenger"
                     , "XF86WebCam"
                     , "XF86MailForward"
                     , "XF86Pictures"
                     , "XF86Music"
                     , "XF86TouchpadToggle"
                     , "XF86_Switch_VT_1"
                     , "XF86_Switch_VT_2"
                     , "XF86_Switch_VT_3"
                     , "XF86_Switch_VT_4"
                     , "XF86_Switch_VT_5"
                     , "XF86_Switch_VT_6"
                     , "XF86_Switch_VT_7"
                     , "XF86_Switch_VT_8"
                     , "XF86_Switch_VT_9"
                     , "XF86_Switch_VT_10"
                     , "XF86_Switch_VT_11"
                     , "XF86_Switch_VT_12"
                     , "XF86_Ungrab"
                     , "XF86_ClearGrab"
                     , "XF86_Next_VMode"
                     , "XF86_Prev_VMode" ]

    -- | Given a configuration record and a list of (key sequence
    --   description, action) pairs, check the key sequence descriptions
    --   for validity, and warn the user (via a popup xmessage window) of
    --   any unparseable or duplicate key sequences.  This function is
    --   appropriate for adding to your @startupHook@, and you are highly
    --   encouraged to do so; otherwise, duplicate or unparseable
    --   keybindings will be silently ignored.
    --
    --   For example, you might do something like this:
    --
    -- > main = xmonad $ myConfig
    -- >
    -- > myKeymap = [("S-M-c", kill), ...]
    -- > myConfig = defaultConfig {
    -- >     ...
    -- >     keys = \c -> mkKeymap c myKeymap
    -- >     startupHook = return () >> checkKeymap myConfig myKeymap
    -- >     ...
    -- > }
    --
    -- NOTE: the @return ()@ in the example above is very important!
    -- Otherwise, you might run into problems with infinite mutual
    -- recursion: the definition of myConfig depends on the definition of
    -- startupHook, which depends on the definition of myConfig, ... and
    -- so on.  Actually, it's likely that the above example in particular
    -- would be OK without the @return ()@, but making @myKeymap@ take
    -- @myConfig@ as a parameter would definitely lead to
    -- problems. Believe me.  It, uh, happened to my friend. In... a
    -- dream. Yeah. In any event, the @return () >>@ introduces enough
    -- laziness to break the deadlock.
    --
    checkKeymap :: XConfig l -> [(String, a)] -> X ()
    checkKeymap conf km = warn (doKeymapCheck conf km)
      where warn ([],[])   = return ()
            warn (bad,dup) = spawn $ "xmessage 'Warning:\n"
                                ++ msg "bad" bad ++ "\n"
                                ++ msg "duplicate" dup ++ "'"
            msg _ [] = ""
            msg m xs = m ++ " keybindings detected: " ++ showBindings xs
            showBindings = unwords . map (("\""++) . (++"\""))

    -- | Given a config and a list of (key sequence description, action)
    --   pairs, check the key sequence descriptions for validity,
    --   returning a list of unparseable key sequences, and a list of
    --   duplicate key sequences.
    doKeymapCheck :: XConfig l -> [(String,a)] -> ([String], [String])
    doKeymapCheck conf km = (bad,dups)
      where ks = map ((readKeySequence conf &&& id) . fst) km
            bad = nub . map snd . filter (isNothing . fst) $ ks
            dups = map (snd . head)
                 . filter ((>1) . length)
                 . groupBy ((==) `on` fst)
                 . sortBy (comparing fst)
                 . map (first fromJust)
                 . filter (isJust . fst)
                 $ ks