July 2009 - xmonad - Haskell.org

Compile-time verification of keymaps
by Gwern Branwen 28 Mar '10

28 Mar '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 So today I edited into my xmonad.hs a binding to the Isohunt.com XMonad.Actions.Search engine for convenience. I naturally chose xK_i for the bound key. When I reloaded, I was surprised to see that mod-i failed to do as it was supposed to. Trying it again, it brought up irssi. That was when I realized mod-i had already been bound in my xmonad.hs, to runOrRaise for irssi, and that the irssi binding happened to be later in the list and so it quietly overwrote the Isohunt binding. After picking a new & unused key, I began reflecting on this. Certainly, this is expected behavior if you're familiar with Data.Map. fromList will do that - a list may have multiple values for a single key (such as xK_i) and the last value wins. But I think in an xmonad.hs, the context is somewhat different. There the semantics are somewhat different. We use 'M.fromList [stuff, more stuff, and the rest]' syntax because Haskell supports list syntax, and it makes life easier on the user to use such a common method. But do we *really* mean to say that it is a sensible thing to bind the same key to multiple contradictory definitions? It just so happens that [xK_i isohunt, xK_i irssi] is equivalent to a destructive update style of 'i = isohunt; i = irssi' when fed through the Map functions. So I thought to myself that maybe there was some static way of specifying a list without duplicates we could use in xmonad.hs. It would be nice to know that one cannot run xmonad.hs with inconsistent sets of bindings*. This checking would, even better, be done at compile-time so one could verify this by simply loading in GHCi (good for everyone who routinely reloads in Emacs or Vim). How to do this? Someone in #haskell suggested extensible records, but that sounds quite difficult. Another approach would be to scrap the static requirement, and simply provide the user a redefined 'fromList' which runs something like 'let x = map fst list in nub x == x' and does something if there are duplicates (calls error, spawns xmessage, etc.) I decided to try a variant of the latter at compile-time, using Template Haskell. I got fairly far with the help of mmorrow, but I didn't actually succeed. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEAREKAAYFAkkgYvgACgkQvpDo5Pfl1oLE3gCgkuHMlUO1+YT4oEFLzhHqmeuB QA4An3X72j1z+StumSOmnTXlTJhHeTft =fBDz -----END PGP SIGNATURE----- The idea is that one should be able to do something like this in xmonad.hs > '{-# LANGUAGE TemplateHaskell #-} > import XMonad.Utils.VerifyKeys > .... > myKeys conf@(XConfig {modMask = m}) = M.fromList $(uniqueTupleListQ [ -- rebind standard actions > ((m .|. shiftMask,xK_p), shellPrompt greenXPConfig) > , ((m, xK_d), raiseBrowser) ] ) VerifyKeys looks something like this: > {-# LANGUAGE TemplateHaskell #-} > module XMonad.Utils.VerifyKeys where > > import Data.List(nub) > import qualified Data.Map > import Language.Haskell.TH.Lib > import Language.Haskell.TH.Syntax > > uniqueTupleListQ :: (Eq a, Lift a, Lift b) => [(a, b)] -> ExpQ > uniqueTupleListQ xs = let ys = map fst xs > ns = nub ys > in case ys == ns of > False -> fail "uniqueTupleListQ: List has conflicting entries." > True -> lift xs The idea is that since we know the keymap at compile-time, we pass it, before it gets turned into a Map (and the relevant information lost), we analyze the list. 'fail' aborts the compilation if the list is bad. You can easily test this out in a different module with some simple expressions: > keymap1, keymap2 :: [(Char, String)] > keymap1 = $(uniqueTupleListQ [('a', "foo"), ('b', "bar")] ) > keymap2 = $(uniqueTupleListQ [('a', "foo"), ('b', "bar"), ('c', "bar"), ('a', "quux")] ) Compiling, this gives us something like this: > [1 of 2] Compiling Tmp ( Tmp.hs, Tmp.o ) > [2 of 2] Compiling Main ( xmonad.hs, xmonad.o ) > Loading package base ... linking ... done. > Loading package array-0.1.0.0 ... linking ... done. > Loading package packedstring-0.1.0.0 ... linking ... done. > Loading package containers-0.1.0.1 ... linking ... done. > Loading package pretty-1.0.0.0 ... linking ... done. > Loading package template-haskell ... linking ... done. > > xmonad.hs:113:12: uniqueTupleListQ: List has conflicting entries. Line 133 is keymap2. If we remove '('a', "quux")', which conflicts with the very first entry, we get: > [1 of 2] Compiling Tmp ( Tmp.hs, Tmp.o ) > [2 of 2] Compiling Main ( xmonad.hs, xmonad.o ) > Loading package base ... linking ... done. > Loading package array-0.1.0.0 ... linking ... done. > Loading package packedstring-0.1.0.0 ... linking ... done. > Loading package containers-0.1.0.1 ... linking ... done. > Loading package pretty-1.0.0.0 ... linking ... done. > Loading package template-haskell ... linking ... done. > Linking foo ... Now, this seems to be exactly what we want, doesn't it? But ultimately I had to admit failure. Template Haskell has a number of restrictions and omissions that make it unfeasible to use. For starters: If we apply uniqueTupleList to an actual keymap (like mine), we discover that uniqueTupleList's constraints are unworkable. Per the type sig, we need 'Lift b', the second half of each tuple in the key list. But XMonad requires b to be a X (), and X () is not instantiated for Lift**. Were it, we would still need Lift instances for Word64 and also CUInt. Lift instances probably wouldn't be too hard to write. The real killer, from an xmonad.hs perspective, is the module restrictions. Fundamentally, one *cannot* use inside a $() anything defined in the same file. {modMask = m}? Nope. greenXPConfig? Nope. 'term = XMonad.terminal conf'? Nope. And so on. It is a minimal set of bindings indeed which only makes use of literals and imported functions. So until Template Haskell improves, that avenue seems to be out. I'm not sure where to go from here. Had Template Haskell worked out, the path would've been easy, a matter of having users make a relatively small modification to their xmonad.hs, and perhaps avoiding entirely TH syntax. Does anyone have a better approach, or is this a foolish thing to want static safety in? ksf suggested that Yi has a combinator approach to keybindings which could solve it, but I am unsure how that works or could be adapted for XMonad.*** * Obviously the consistency is only valuable _in_ a specific Map; if we insisted that all Maps be consistent, then we couldn't override the default Map with our own. ** I may be misinterpreting the type error; possibly we actually need Lift for (X()) *** I'm cc'ing yi-devel since I suspect the topic may be of interest. -- gwern

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darcs patch: Replace custom forever_ with library equivalent
by Daniel Schoepe 27 Mar '10

27 Mar '10

Replaced a custom forever implementation in Main.hsc by the equivalent from the standard libraries. I guess it was legacy code, since forever wasn't in Control.Monad in ghc 6.6 as far as I know. Wed Jan 14 22:55:56 CET 2009 Daniel Schoepe <asgaroth_(a)gmx.de> * Replaced custom forever_ by library function New patches: [Replaced custom forever_ by library function Daniel Schoepe <asgaroth_(a)gmx.de>**20090114215556] { hunk ./XMonad/Main.hsc 146 userCode $ startupHook initxmc -- main loop, for all you HOF/recursion fans out there. - forever_ $ prehandle =<< io (nextEvent dpy e >> getEvent e) + forever $ prehandle =<< io (nextEvent dpy e >> getEvent e) return () where hunk ./XMonad/Main.hsc 150 - forever_ a = a >> forever_ a - -- if the event gives us the position of the pointer, set mousePosition prehandle e = let mouse = do guard (ev_event_type e `elem` evs) return (fromIntegral (ev_x_root e) } Context: [Call logHook as the very last action in windows Spencer Janssen <spencerjanssen(a)gmail.com>**20081209233700 Ignore-this: 4396ad891b607780f8e4b3b6bbce87e ] [Accept inferior crossing events. This patch enables fmouse-focus-follows-screen Spencer Janssen <spencerjanssen(a)gmail.com>**20081205045130 Ignore-this: 3ac329fb92839827aed0a4370784cabd ] [Tile all windows at once Spencer Janssen <spencerjanssen(a)gmail.com>**20081118074447] [Factor rational rect scaling into a separate function Spencer Janssen <spencerjanssen(a)gmail.com>**20081118072849] [Change screen focus by clicking on the root window. Spencer Janssen <spencerjanssen(a)gmail.com>**20081106224031 This is a modification of a patch from Joachim Breitner. ] [Fix #192. Spencer Janssen <spencerjanssen(a)gmail.com>**20081021220059] [select base < 4 for building on ghc 6.10 Adam Vogt <vogt.adam(a)gmail.com>**20081013214509] [add killWindow function Joachim Breitner <mail(a)joachim-breitner.de>**20081005001804 This is required to kill anything that is not focused, without having to focus it first. ] [add'l documentation Devin Mullins <me(a)twifkak.com>**20080927234639] [Regression: ungrab buttons on *non* root windows Spencer Janssen <spencerjanssen(a)gmail.com>**20081007214351] [Partial fix for #40 Spencer Janssen <spencerjanssen(a)gmail.com>**20081007212053 Improvements: - clicking on the root will change focus to that screen - moving the mouse from a window on a screen to an empty screen changes focus to that screen The only remaining issue is that moving the mouse between two empty screens does not change focus. In order to solve this, we'd have to select motion events on the root window, which is potentially expensive. ] [Track mouse position via events received Spencer Janssen <spencerjanssen(a)gmail.com>**20081007203953] [Fix haddock Spencer Janssen <spencerjanssen(a)gmail.com>**20081007094641] [Move screen locating code into pointScreen Spencer Janssen <spencerjanssen(a)gmail.com>**20081007094207] [Make pointWithin a top-level binding Spencer Janssen <spencerjanssen(a)gmail.com>**20081007090229] [sp README, CONFIG, STYLE, TODO gwern0(a)gmail.com**20080913024457] [Use the same X11 dependency as xmonad-contrib Spencer Janssen <spencerjanssen(a)gmail.com>**20080921061508] [Export focusUp' and focusDown' -- work entirely on stacks Spencer Janssen <spencerjanssen(a)gmail.com>**20080911214803] [add W.shiftMaster, fix float/tile-reordering bug Devin Mullins <me(a)twifkak.com>**20080911053909] [TAG 0.8 Spencer Janssen <spencerjanssen(a)gmail.com>**20080905195412] [Spelling. Any bets on how long this has been there? Spencer Janssen <spencerjanssen(a)gmail.com>**20080905195211] [Bump version to 0.8 Spencer Janssen <spencerjanssen(a)gmail.com>**20080905194225] [Remove obsolete comments about darcs X11 Spencer Janssen <spencerjanssen(a)gmail.com>**20080905194915] [Recommend latest packages rather than specific versions Spencer Janssen <spencerjanssen(a)gmail.com>**20080905194837] [Also remove -optl from the executable section Spencer Janssen <spencerjanssen(a)gmail.com>**20080820210023] [-optl-Wl,-s is not needed with recent Cabal versions Spencer Janssen <spencerjanssen(a)gmail.com>**20080820204102] [Haddock links Malebria <malebria(a)riseup.net>**20080601212515] [Haddock syntax for enumeration Malebria <malebria(a)riseup.net>**20080601204951] [I prefer the spencerjanssen(a)gmail.com address now Spencer Janssen <spencerjanssen(a)gmail.com>**20080714202650] [Raise windows in the floating layer when moving or resizing Trevor Elliott <trevor(a)galois.com>**20080521215057] [add currentTag convenience function Devin Mullins <me(a)twifkak.com>**20080511224258] [Make Mirror a newtype Spencer Janssen <sjanssen(a)cse.unl.edu>**20080508104640] [Comments Spencer Janssen <sjanssen(a)cse.unl.edu>**20080507013122] [Break long line Spencer Janssen <sjanssen(a)cse.unl.edu>**20080507012608] [Style Spencer Janssen <sjanssen(a)cse.unl.edu>**20080507012519] [Simplify Spencer Janssen <sjanssen(a)cse.unl.edu>**20080507011309] [Overhaul Choose, fixes issue 183 Spencer Janssen <sjanssen(a)cse.unl.edu>**20080506220809] [Remember if focus changes were caused by mouse actions or by key commands Klaus Weidner <kweidner(a)pobox.com>**20080502175603 If the user used the mouse to change window focus (moving into or clicking on a window), this should be handled differently than focus changes due to keyboard commands. Specifically, it's inappropriate to discard window enter/leave events while the mouse is moving. This fixes the bug where a fast mouse motion across multiple windows resulted in the wrong window keeping focus. It's also helpful information for contrib modules such as UpdatePointer - it's supposed to move the mouse pointer only in response to keyboard actions, not if the user was moving the mouse. ] [Wibble Spencer Janssen <sjanssen(a)cse.unl.edu>**20080506203840] [Added doShift function for more user-friendly hooks Ivan N. Veselov <veselov(a)gmail.com>**20080506185757] [use named colours. fixes startup failure on the XO Don Stewart <dons(a)galois.com>**20080502210149] [Set focus *after* revealing windows Spencer Janssen <sjanssen(a)cse.unl.edu>**20080407222559] [Reveal windows after moving/resizing them. Spencer Janssen <sjanssen(a)cse.unl.edu>**20080407220756 This should reduce the number of repaints for newly visible windows. ] [Hide newly created but non-visible windows (fixes bug #172) Spencer Janssen <sjanssen(a)cse.unl.edu>**20080430014012] [formatting, eta expansion Don Stewart <dons(a)galois.com>**20080418184337] [XMonad.ManageHook: add 'appName', another name for 'resource' Lukas Mai <l.mai(a)web.de>**20080406012006] [XMonad.ManageHook: make 'title' locale-aware; haddock cleanup Lukas Mai <l.mai(a)web.de>**20080406011338 The code for 'title' was stolen from getname.patch (bug #44). ] [XMonad.Main: call setlocale on startup Lukas Mai <l.mai(a)web.de>**20080406011234] [floats always use current screen (with less bugs) robreim(a)bobturf.org**20080405135009] [XMonad.Operations: applySizeHint reshuffle Lukas Mai <l.mai(a)web.de>**20080404215615 Make applySizeHints take window borders into account. Move old functionality to applySizeHintsContents. Add new mkAdjust function that generates a custom autohinter for a window. ] [XMonad.Layout: documentation cleanup Lukas Mai <l.mai(a)web.de>**20080404215444] [Remove gaps from the example config Spencer Janssen <sjanssen(a)cse.unl.edu>**20080329232959] [Remove gaps Spencer Janssen <sjanssen(a)cse.unl.edu>**20080325091526] [TAG 0.7 Spencer Janssen <sjanssen(a)cse.unl.edu>**20080329210249] Patch bundle hash: ef4a14f0e22b06712aac9975c8df956a9b2846ba

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Call for xmonad.hs
by Gwern Branwen 16 Jan '10

16 Jan '10

Hi everyone. So a while ago we were discussing how to improve defaults and what sorts of types and functions XM and XMC could provide which encapsulate common behavior, when Devon asked me what exactly I saw being repeated (besides the 2 or 3 examples I provided), and it occurred to me that I really didn't know. There're ~30 xmonad.hs's here <http://haskell.org/haskellwiki/Xmonad/Config_archive>, but perhaps 1/3 to 1/2 are obsolete or don't compile with darcs XM/XMC (at a very rough guess). I'd like more. So here's what I would greatly appreciate everyone doing: 1) Upload your config 2) If you've uploaded your config, update it! 3) If you use someone else's config, why not mention it? I'd appreciate knowing who's using what, so I can count the popular configurations proportionately* 4) If you don't want to do any of 1-3, perhaps you could email me privately with your config? Thanks in advance all. * I think it's fair to say that if 10 people are using a particular xmonad.hs, and there's a simplification which could be made, that change should count 10x -- gwern ANZUS nuclear Lebed .ch Domination .tm top Amherst USSS Hugo

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Changing module headers
by Gwern Branwen 20 Dec '09

20 Dec '09

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 So I mentioned a while ago I meant to go over XMC using the 'sim' tool (with an invocation like sim_mira `find . -name "*.hs"` - I discovered recently that it had Miranda support, which means quasi-Haskell support). But the results are littered with comments. Particularly obnoxious are the module headers, in part because they all seem to use '--' comments even if they cover dozens of lines. Would anyone object if I were to edit those to use {- -} style (and push those edits without review)? - -- gwern -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEAREKAAYFAko+xRkACgkQvpDo5Pfl1oJuNwCgi4IhXrPLMdOHlWdReKTcMH2f GbUAn0pT7fM9dnLYW0acoaQrVKc2H51w =ngUp -----END PGP SIGNATURE-----

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xmonad from gnome-session-2.26
by Joachim Breitner 20 Sep '09

20 Sep '09

Hi, If you want to use xmonad from gnome-session-2.26, the correct way seems to be to specify # gconftool-2 -s /desktop/gnome/session/required_components/windowmanager xmonad --type string This unfortunately has the effect that gnome-session waits a few seconds for the window manger (now xmonad) to register via dbus, see http://live.gnome.org/SessionManagement/GnomeSession xmonad does not support the gnome-session protocol, but you can work around the delay with this code in xmonad.hs import XMonad [...] import System.Environment import System.Cmd [...] main = do env <- getEnvironment case lookup "DESKTOP_AUTOSTART_ID" env of Just id -> do rawSystem "dbus-send" ["--session","--print-reply=string","--dest=org.gnome.SessionManager","/org/gnome/SessionManager","org.gnome.SessionManager.RegisterClient","string:xmonad","string:"++id] return () Nothing -> return () xmonad $ defaultConfig { [...] -- simple stuff } I guess some stuff can be improved about this, such as using the DBus package from hackage, but it’s a start. Greetings, Joachim -- Joachim Breitner e-Mail: mail(a)joachim-breitner.de Homepage: http://www.joachim-breitner.de ICQ#: 74513189 Jabber-ID: nomeata(a)joachim-breitner.de

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Unmarking modules 'Unstable' in contrib
by Adam Vogt 03 Sep '09

03 Sep '09

Hello, Most (152/159) modules are marked as unstable in contrib. A good number of these 'unstable' modules have not been modified since a number of releases. Here's a rough total number of modules with a last-modified date (per year): > (for x in `find .`; do; (darcs changes $x | tail -n 2 | head -n 1); done) > lastmod > for x in {2007,2008,2009}; do; grep $x lastmod | wc -l; done 64 43 17 I wouldn't trust those numbers, since the total falls short of 159, but the point still stands: many so-called unstable modules have not changed in a long time, which could make it difficult for users to avoid modules that may actually change. Does anybody mind if I change the oldest modules (unchanged since 1.5 years) to be stable? -- Adam

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xmonad-fork
by Gwern Branwen 02 Sep '09

02 Sep '09

I came across this today linked in #darcs: http://physics.oregonstate.edu/~roundyd/codes.php "xmonad-fork xmonad-fork is a modified version of the xmonad window manager that I use. You can get a copy of the source with darcs get http://physics.oregonstate.edu/~roundyd/code/xmonad-fork" 'twould seem Andrea and David have been collaborating extensively on xmonad (by my count, there ~106 patches in this repo not present in core/xmc). Some of them look interesting, but others deal with internals I'm not very familiar with. -- gwern

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darcs patch: Pester the user with one (not two) xmess... (and 4 more)
by Adam Vogt 31 Aug '09

31 Aug '09

Sat Mar 21 19:37:36 EDT 2009 Adam Vogt <vogt.adam(a)gmail.com> * Pester the user with one (not two) xmessages on config errors Sat Mar 21 19:29:07 EDT 2009 Adam Vogt <vogt.adam(a)gmail.com> * Add lib to ghc searchpath with recompilation check Sun May 3 19:54:15 EDT 2009 Adam Vogt <vogt.adam(a)gmail.com> * Only watch mtime for .hs, .lhs, .hsc for ~/.xmonad/lib Previously xmonad would force a recompile due to the object files being too new, so only look at files which may contain haskell code. Thu Jul 9 21:13:08 EDT 2009 Adam Vogt <vogt.adam(a)gmail.com> * Set infix 0 --> to reduce parentheses in ManageHooks What was previously: > (appName ?= x <&&> classname ?= y) --> (doFloat <+> doIgnore) Can now be: > appName ?= x <&&> classname ?= y --> doFloat <+> doIgnore Thu Jul 9 21:14:24 EDT 2009 Adam Vogt <vogt.adam(a)gmail.com> * Remove tabs from ManageHook.hs

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Bug in X.A.Submap
by Khudyakov Alexey 05 Aug '09

05 Aug '09

Hello I've submitted a bug some time ago. I didn't get any response, so I'm reposing it to ML. http://code.google.com/p/xmonad/issues/detail?id=295 Submap actions don't work when in russian layout. In english layout it does work without problem. Standard xmonad key bindings work in both layouts. I'm using version from darcs. 0.8 is affected to AFAIR. Layout are set up with XCB. $ setxkbmap -model pc104 -layout us,ru -variant basic,winkeys $ setxkbmap -option -option \ "grp_led:scroll,grp:shifts_toggle,compose:menu,ctrl:nocaps" Below is snippet from X.A.Submap. Quick research shown that keymasks m and m' has bit (1<<13) set when russian layout chosen. I have no idea how to interpret it. All valid keymasks are <= (1<<12) as declared in X11 headers. > -- | Like 'submap', but executes a default action if the key did not match. > submapDefault :: X () -> M.Map (KeyMask, KeySym) (X ()) -> X () > submapDefault def keys = do > XConf { theRoot = root, display = d } <- ask > > io $ grabKeyboard d root False grabModeAsync grabModeAsync currentTime > > (m, s) <- io $ allocaXEvent $ \p -> fix $ \nextkey -> do > maskEvent d keyPressMask p > KeyEvent { ev_keycode = code, ev_state = m } <- getEvent p > keysym <- keycodeToKeysym d code 0 > if isModifierKey keysym > then nextkey > else return (m, keysym) > > m' <- cleanMask m > > maybe def id (M.lookup (m', s) keys) > > io $ ungrabKeyboard d currentTime -- Khudyakov Alexey

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code for moving/resizing windows in xmonad wiki
by Chengqi Song 31 Jul '09

31 Jul '09

Dear All, Just for your information: http://haskell.org/haskellwiki/Xmonad/Config_archive /lars' xmonad.hs Move/Resize windows using keyboard easily: 1. move window around using M-Arrows. 2. resize windows using C-Arrows. 3. Holding <Shift> to move/resize 2 pixels per step instead of 20 pixels. Please find the lines below comment "-- moving floating window with key" to see details. Thanks to the powerful haskell, the definition for those 4*2*2 = 16 key bindings is quite simple: -- moving floating window with key [(c ++ m ++ k, withFocused $ f (d x)) | (d, k) <- zip [\a->(a, 0), \a->(0, a), \a->(0-a, 0), \a->(0, 0-a)] ["<Right>", "<Down>", "<Left>", "<Up>"] , (f, m) <- zip [keysMoveWindow, \d -> keysResizeWindow d (0, 0)] ["M-", "M-S-"] , (c, x) <- zip ["", "C-"] [20, 2]] I personally found it's very convenient. Hope it can help who want keybindings for moving/resizing windows. lars

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