September 2009 - Libraries

Proposal #3339: Add (+>) as a synonym for mappend
by Bryan O'Sullivan 08 Nov '11

08 Nov '11

Ticket: http://hackage.haskell.org/trac/ghc/ticket/3339 >From the ticket: This proposal was, I think, originally suggested by Jules Bean. The idea is to add two functions to the Data.Monoid module, (+>) and (<+), corresponding to different uses of mappend. These should not be methods of the Monoidtypeclass, but top-level functions. I hope (but slightly doubt) that the visual nature of the two operators might help to counter the thought that monoids are just for gluing things together. (+>) :: (Monoid a) => a -> a -> a a +> b = a `mappend` b (<+) :: (Monoid a) => a -> a -> a a <+ b = b `mappend` a infixl 4 +> infixl 4 <+ Proposed deadline: two weeks. If this looks reasonable, I'll attach darcs patches.

30 75

There are too many error handling conventions used in library code!
by dons＠cse.unsw.edu.au 13 Aug '11

13 Aug '11

This article on the 8 different error handling strategies various common Haskell libs use: http://www.randomhacks.net/articles/2007/03/10/haskell-8-ways-to-report-err… got me thinking: we need to standardise/recommend a small set of methods for library error handling. The lack of consistent error reporting between libs results in verbose code, as we're not able to use a single error handling technique when gluing together code from different libs (i.e. we can't just use Maybe or Either/ErrorT). (It's always nice when you *can* use, say, a Maybe monad to glue code from a number of sources, but eventually you reach code with a different error system, and the Maybe monad breaks down). So, some questions I think we can tackle: * can we identify error handling strategies from the list that should not be used anymore? (throwDyn?) * can we move some of the outlying libraries to a more consistent error framework? * do we need more support for gluing together our different error systems? (it should be easier to glue code using , say, Maybe/Either). * what role does MonadError play here, as a generic error handler? * can we make precise recommendations about which error strategies to use? -- Don

11 16

Proposal #2629: Data.List: Replace nub; add nubOrd, nubInt, nubWith
by Bart Massey 24 Feb '10

24 Feb '10

http://hackage.haskell.org/trac/ghc/ticket/2629 Everyone always complains about nub, but nobody ever does anything about it except (map head . group . sort), which isn't lazy and isn't always faster. :-) I've implemented a new function nubWith that takes a "stop list" as an argument and filters its target list against the stop list. I've then re-implemented nub and implemented nubOrd and nubInt in terms of nubWith: the stop list is a typeclass, so these implementations are trivial and new implementations are easily added. nubBy is left alone, since there's nothing obvious to be done about it. All of the nubs are still fully lazy. Basic QuickCheck tests are provided, and pass. Performance benchmarking code is provided. The performance of my nub implementation is quite comparable to that of the standard one. My nubOrd and nubInt implementations are dramatically faster, since they use a Set and IntSet respectively for the stop list. In particular, they are performant on long lists with long nubs, unlike the basic nub. My implementation is available via git at git://svcs.cs.pdx.edu/git/nub.git or can be browsed at http://svcs.cs.pdx.edu/gitweb?p=nub.git;a=tree and has a maybe-outdated tarball at http://svcs.cs.pdx.edu/haskell/nub.tar.gz The Nub.hs file itself is attached to the proposal. If the proposal is accepted, I will prepare a patch against current GHC library top-of-tree, but for now it seems easier for everyone to just look at the bits in their current natural habitat.

15 31

Adding an ignore function to Control.Monad
by Gwern Branwen 12 Jan '10

12 Jan '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 So while writing my wp-archivebot, I ran into the issue that forkIO requires IO () but returns IO ThreadId, and that many useful IO functions will return IO a instead of IO (). This forces some awkward contortions. Suppose I want to ping the WebCite website at a particular address, and this request makes WebCite archive a URL embedded in that address. Presumably I could venture into the depths of Network.HTTP to figure out how to ping an URL without also pulling down the server's HTML, but why do that when I already have obviously 'openURL :: String -> IO String'? Much easier to do something like 'openURL "webcite.org" ++ foo ++ "other stuff" '. But my bot needs to handle quite a few URLs; one at a time, what with all the waits and timeouts, isn't going to hack it. So for a given link, I forkIO the openURL request. But of course, forkIO demands IO (), so I toss in a '>> return ()'. Fair enough. So I examine the performance, and it's still too slow. Recent Changes has hundreds of different pages a minute. I'd better fork each page (and then fork for each link). But wait, all those forkIOs are returning IO ThreadIds, and my top-level forkIO call demands IO ()... So another >> return (). At this point, the code is starting to look pretty silly - something like '...stuff >> return ()) >> return ())'. So I see the repeated pattern, and by the rule of 3, factor it out to: - -- | Convenience function. 'forkIO' and 'forM_' demand return types of 'IO ()', but most interesting - -- IO functions don't return void. So one adds a call to 'return ()'; this just factors it out. ignore ∷ (Monad m) ⇒ m a → m () ignore x = x >> return () Not the most complex convenience function I've ever written, but not any simpler than, say Control.Monad.forever or for that matter, most of the stuff in Control.Monad. I'd think it'd be useful for more than just me. Agda is lousy with calls to '>> return ()'; and then there's ZMachine, arrayref, whim, the barracuda packages, binary, bnfc, buddha, bytestring, c2hs, cabal, chesslibrary, comas, conjure, curl, darcs, darcs-benchmark, dbus-haskell, ddc, dephd, derive, dhs, drift, easyvision, ehc, filestore, folkung, geni, geordi, gtk2hs, gnuplot, ginsu, halfs, happstack, haskeline, hback, hbeat... You get the picture. I realize the specific name of 'ignore' can be bikeshedded to death, but it's clear, it's short, Hoogle turns up one other function with ignore in its name (Distribution.ParseUtils ignoreUnrec), and it's been independently named 'ignore' by another Haskeller (lilac). Existing uses of the string 'ignore are rare - it's in a few places as a variable, cabal and cabal-install and ehc and tar have where definitions of an ignore, a test for directory defines an ignore and imports Control.Monad unqualified, fit defines an 'ignore' but doesn't seem to use it in any module that also imports Control.Monad unqualified, halipeto defines an ignore but doesn't import Control.Monad, shim/yi has a let definition of an ignore, yhc has a where definition of an ignore. And that's about it. One of directory's tests would break, and the rest might have an additional -Wall warning. - -- gwern -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEAREKAAYFAkov5Q0ACgkQvpDo5Pfl1oIsRQCghUqynThzcT+OYV1KaYJhGFhv 6yYAnjf7CVOm0+Fg1FBa9IpdVIrRpCZm =Cd8V -----END PGP SIGNATURE-----

18 32

export toDescList from Data.Map
by Evan Laforge 25 Nov '09

25 Nov '09

So, I mentioned this a long time ago but didn't get any responses and then I got distracted. So this time I added a ticket and patch and everything: 2580 Here's the text: It's even implemented, but not exported. Without this, there's apparently no way to iterate over a map from high to low, since foldl is also not exported. Also, I implemented a toDescList for IntMap, and could do the same for Set, and could add those patches, if people agree it's a good idea. In addition, is there any problem with exporting foldl aka descending for the three modules? I implemented a foldl for IntMap and it seems to work, but I'd want someone smarter to look for problems with it. In addition, Set and Map are inconsistent with folds: Set exports 'fold' and says "no order is guaranteed", but it's just defined to foldr, which is in ascending order. Set.foldr itself is not exported. Meanwhile, Map also exports fold, but heavily implies from the doc that it's guaranteed to be ascending. Would it restrict implementation changes too much to export a descending fold for all three? Other languages that have tree oriented general purpose maps all let you start anywhere and iterate in either direction. Anyway, is 2-3 weeks ok for discussion period? The library submission wiki doesn't say how long.

6 13

Proposal: System.FilePath: current directory should be ".", not ""
by Simon Marlow 15 Nov '09

15 Nov '09

See http://hackage.haskell.org/trac/ghc/ticket/2034 to which I have attached a fairly simple patch. All the tests pass. The main change is that splitFileName "foo" = (".", "foo") and takeDirectory "foo" = "." and "." </> x = x Discussion period: 2 weeks (5 October) Cheers, Simon

12 18

Three patches for cabal
by Niklas Broberg 09 Nov '09

09 Nov '09

(Trying again since my previous patches were too big for the list.) While doing a survey[1] of the extensions registered with Cabal, I came across two warts in the list of constructors, and one constructor that should be deprecated. First there's the constructor called TransformListComp, which should really be named GeneralizedListComp, since the constructor should describe the extension and not the implementation scheme. Second there's the constructor NoMonoPatBinds, which actually describes the default Haskell 98 behavior, even if GHC has a different default. It's GHC's behavior that is the extension, so the constructor in cabal should really be named MonoPatBinds. Also, the PatternSignatures constructor has been deprecated in GHC and superceded by ScopedTypeVariables. The attached patches (three in one file) adds the proposed new constructors, deprecates the old ones, and adds documentation. Cheers, /Niklas

8 15

Add instance IsString ShowS where fromString = showString
by Bas van Dijk 13 Oct '09

13 Oct '09

Hello, It would be really nice to use OverloadedStrings when constructing a ShowS, for example in a definition of showsPrec in an instance for Show. The patch attached in the ticket[3544] adds the necessary instance to base/GHC/Show.lhs: instance IsString ShowS where fromString = showString Note that this does require TypeSynonymInstances. Discussion period 2 weeks. regards, Bas [3544] http://hackage.haskell.org/trac/ghc/ticket/3544

7 9

darcs patch: haskell-x11: add and export the list of cursors
by Andres Salomon 01 Oct '09

01 Oct '09

Tue Sep 15 11:57:08 EDT 2009 Andres Salomon <dilinger(a)collabora.co.uk> * haskell-x11: add and export the list of cursors Pulled in from X11/cursorfont.h, export things like xC_X_cursor and xC_left_ptr for things like createFontCursor to use. New patches: [haskell-x11: add and export the list of cursors Andres Salomon <dilinger(a)collabora.co.uk>**20090915155708 Ignore-this: 995cede8cdd8830a2c0bb6c63b8229b9 Pulled in from X11/cursorfont.h, export things like xC_X_cursor and xC_left_ptr for things like createFontCursor to use. ] { addfile ./Graphics/X11/Xlib/Cursor.hsc hunk ./Graphics/X11/Xlib/Cursor.hsc 1 +----------------------------------------------------------------------------- +-- | +-- Module : Graphics.X11.Xlib.Cursor +-- Copyright : (C) Collabora Ltd 2009 +-- License : BSD-style (see the file libraries/base/LICENSE) +-- +-- Maintainer : libraries(a)haskell.org +-- Stability : provisional +-- Portability : portable +-- +-- A collection of cursor types defined by /usr/include/X11/cursorfont.h. +-- +----------------------------------------------------------------------------- + +module Graphics.X11.Xlib.Cursor( + + xC_X_cursor, + xC_arrow, + xC_based_arrow_down, + xC_based_arrow_up, + xC_boat, + xC_bogosity, + xC_bottom_left_corner, + xC_bottom_right_corner, + xC_bottom_side, + xC_bottom_tee, + xC_box_spiral, + xC_center_ptr, + xC_circle, + xC_clock, + xC_coffee_mug, + xC_cross, + xC_cross_reverse, + xC_crosshair, + xC_diamond_cross, + xC_dot, + xC_dotbox, + xC_double_arrow, + xC_draft_large, + xC_draft_small, + xC_draped_box, + xC_exchange, + xC_fleur, + xC_gobbler, + xC_gumby, + xC_hand1, + xC_hand2, + xC_heart, + xC_icon, + xC_iron_cross, + xC_left_ptr, + xC_left_side, + xC_left_tee, + xC_leftbutton, + xC_ll_angle, + xC_lr_angle, + xC_man, + xC_mouse, + xC_pencil, + xC_pirate, + xC_plus, + xC_question_arrow, + xC_right_ptr, + xC_right_side, + xC_right_tee, + xC_rightbutton, + xC_rtl_logo, + xC_sailboat, + xC_sb_down_arrow, + xC_sb_h_double_arrow, + xC_sb_left_arrow, + xC_sb_right_arrow, + xC_sb_up_arrow, + xC_sb_v_double_arrow, + xC_shuttle, + xC_sizing, + xC_spider, + xC_spraycan, + xC_star, + xC_target, + xC_tcross, + xC_top_left_arrow, + xC_top_left_corner, + xC_top_right_corner, + xC_top_side, + xC_top_tee, + xC_trek, + xC_ul_angle, + xC_umbrella, + xC_ur_angle, + xC_watch, + xC_xterm, + + ) where + +import Graphics.X11.Xlib.Font + +---------------------------------------------------------------- +-- Cursors +---------------------------------------------------------------- + +#include "HsXlib.h" + +xC_X_cursor :: Glyph +xC_X_cursor = #const XC_X_cursor + +xC_arrow :: Glyph +xC_arrow = #const XC_arrow + +xC_based_arrow_down :: Glyph +xC_based_arrow_down = #const XC_based_arrow_down + +xC_based_arrow_up :: Glyph +xC_based_arrow_up = #const XC_based_arrow_up + +xC_boat :: Glyph +xC_boat = #const XC_boat + +xC_bogosity :: Glyph +xC_bogosity = #const XC_bogosity + +xC_bottom_left_corner :: Glyph +xC_bottom_left_corner = #const XC_bottom_left_corner + +xC_bottom_right_corner :: Glyph +xC_bottom_right_corner = #const XC_bottom_right_corner + +xC_bottom_side :: Glyph +xC_bottom_side = #const XC_bottom_side + +xC_bottom_tee :: Glyph +xC_bottom_tee = #const XC_bottom_tee + +xC_box_spiral :: Glyph +xC_box_spiral = #const XC_box_spiral + +xC_center_ptr :: Glyph +xC_center_ptr = #const XC_center_ptr + +xC_circle :: Glyph +xC_circle = #const XC_circle + +xC_clock :: Glyph +xC_clock = #const XC_clock + +xC_coffee_mug :: Glyph +xC_coffee_mug = #const XC_coffee_mug + +xC_cross :: Glyph +xC_cross = #const XC_cross + +xC_cross_reverse :: Glyph +xC_cross_reverse = #const XC_cross_reverse + +xC_crosshair :: Glyph +xC_crosshair = #const XC_crosshair + +xC_diamond_cross :: Glyph +xC_diamond_cross = #const XC_diamond_cross + +xC_dot :: Glyph +xC_dot = #const XC_dot + +xC_dotbox :: Glyph +xC_dotbox = #const XC_dotbox + +xC_double_arrow :: Glyph +xC_double_arrow = #const XC_double_arrow + +xC_draft_large :: Glyph +xC_draft_large = #const XC_draft_large + +xC_draft_small :: Glyph +xC_draft_small = #const XC_draft_small + +xC_draped_box :: Glyph +xC_draped_box = #const XC_draped_box + +xC_exchange :: Glyph +xC_exchange = #const XC_exchange + +xC_fleur :: Glyph +xC_fleur = #const XC_fleur + +xC_gobbler :: Glyph +xC_gobbler = #const XC_gobbler + +xC_gumby :: Glyph +xC_gumby = #const XC_gumby + +xC_hand1 :: Glyph +xC_hand1 = #const XC_hand1 + +xC_hand2 :: Glyph +xC_hand2 = #const XC_hand2 + +xC_heart :: Glyph +xC_heart = #const XC_heart + +xC_icon :: Glyph +xC_icon = #const XC_icon + +xC_iron_cross :: Glyph +xC_iron_cross = #const XC_iron_cross + +xC_left_ptr :: Glyph +xC_left_ptr = #const XC_left_ptr + +xC_left_side :: Glyph +xC_left_side = #const XC_left_side + +xC_left_tee :: Glyph +xC_left_tee = #const XC_left_tee + +xC_leftbutton :: Glyph +xC_leftbutton = #const XC_leftbutton + +xC_ll_angle :: Glyph +xC_ll_angle = #const XC_ll_angle + +xC_lr_angle :: Glyph +xC_lr_angle = #const XC_lr_angle + +xC_man :: Glyph +xC_man = #const XC_man + +xC_middlebutton :: Glyph +xC_middlebutton = #const XC_middlebutton + +xC_mouse :: Glyph +xC_mouse = #const XC_mouse + +xC_pencil :: Glyph +xC_pencil = #const XC_pencil + +xC_pirate :: Glyph +xC_pirate = #const XC_pirate + +xC_plus :: Glyph +xC_plus = #const XC_plus + +xC_question_arrow :: Glyph +xC_question_arrow = #const XC_question_arrow + +xC_right_ptr :: Glyph +xC_right_ptr = #const XC_right_ptr + +xC_right_side :: Glyph +xC_right_side = #const XC_right_side + +xC_right_tee :: Glyph +xC_right_tee = #const XC_right_tee + +xC_rightbutton :: Glyph +xC_rightbutton = #const XC_rightbutton + +xC_rtl_logo :: Glyph +xC_rtl_logo = #const XC_rtl_logo + +xC_sailboat :: Glyph +xC_sailboat = #const XC_sailboat + +xC_sb_down_arrow :: Glyph +xC_sb_down_arrow = #const XC_sb_down_arrow + +xC_sb_h_double_arrow :: Glyph +xC_sb_h_double_arrow = #const XC_sb_h_double_arrow + +xC_sb_left_arrow :: Glyph +xC_sb_left_arrow = #const XC_sb_left_arrow + +xC_sb_right_arrow :: Glyph +xC_sb_right_arrow = #const XC_sb_right_arrow + +xC_sb_up_arrow :: Glyph +xC_sb_up_arrow = #const XC_sb_up_arrow + +xC_sb_v_double_arrow :: Glyph +xC_sb_v_double_arrow = #const XC_sb_v_double_arrow + +xC_shuttle :: Glyph +xC_shuttle = #const XC_shuttle + +xC_sizing :: Glyph +xC_sizing = #const XC_sizing + +xC_spider :: Glyph +xC_spider = #const XC_spider + +xC_spraycan :: Glyph +xC_spraycan = #const XC_spraycan + +xC_star :: Glyph +xC_star = #const XC_star + +xC_target :: Glyph +xC_target = #const XC_target + +xC_tcross :: Glyph +xC_tcross = #const XC_tcross + +xC_top_left_arrow :: Glyph +xC_top_left_arrow = #const XC_top_left_arrow + +xC_top_left_corner :: Glyph +xC_top_left_corner = #const XC_top_left_corner + +xC_top_right_corner :: Glyph +xC_top_right_corner = #const XC_top_right_corner + +xC_top_side :: Glyph +xC_top_side = #const XC_top_side + +xC_top_tee :: Glyph +xC_top_tee = #const XC_top_tee + +xC_trek :: Glyph +xC_trek = #const XC_trek + +xC_ul_angle :: Glyph +xC_ul_angle = #const XC_ul_angle + +xC_umbrella :: Glyph +xC_umbrella = #const XC_umbrella + +xC_ur_angle :: Glyph +xC_ur_angle = #const XC_ur_angle + +xC_watch :: Glyph +xC_watch = #const XC_watch + +xC_xterm :: Glyph +xC_xterm = #const XC_xterm + +---------------------------------------------------------------- +-- End +---------------------------------------------------------------- hunk ./Makefile.nhc98 12 Graphics/X11/Xlib/Atom.hsc \ Graphics/X11/Xlib/Color.hs \ Graphics/X11/Xlib/Context.hs \ + Graphics/X11/Xlib/Cursor.hsc \ Graphics/X11/Xlib/Display.hs \ Graphics/X11/Xlib/Event.hsc \ Graphics/X11/Xlib/Font.hsc \ hunk ./X11.cabal 31 Graphics.X11.Xlib.Atom, Graphics.X11.Xlib.Color, Graphics.X11.Xlib.Context, + Graphics.X11.Xlib.Cursor, Graphics.X11.Xlib.Display, Graphics.X11.Xlib.Event, Graphics.X11.Xlib.Font, hunk ./configure.ac 118 if ! test "$have_keysymdef" = yes; then echo "WARNING: Couldn't find <X11/keysymdef.h> for X.org keysyms" fi + + AC_CHECK_HEADERS([X11/cursorfont.h], [have_cursorfont=yes]) + if ! test "$have_cursorfont" = yes; then + AC_MSG_ERROR([X11/cursorfont.h (from libx11) is required]) + fi fi hunk ./include/HsXlib.h 40 #define XK_LATIN1 #include <X11/keysymdef.h> +#include <X11/cursorfont.h> + /* This error handler is used from FFI code. * It generates a slightly better error message than the one * that comes with Xlib. } Context: [TAG 1.4.5 Spencer Janssen <spencerjanssen(a)gmail.com>**20081203050348 Ignore-this: d8112e4ff25ec56fe5ac2cdc9fa1ead ] [Bump version to 1.4.5 Spencer Janssen <spencerjanssen(a)gmail.com>**20081203050251 Ignore-this: 665f8093d82bef9e6b13bf1e4db74e1d ] [Bump configure.ac to 1.4.4 as well Spencer Janssen <spencerjanssen(a)gmail.com>**20081203050154 Ignore-this: ef3fabf26fc7dbfdb6dfaa92073e3c9e ] [Fix memory leak in getWMHints Spencer Janssen <spencerjanssen(a)gmail.com>**20081125221512 Ignore-this: dacc19acbb60e13d945509cde0551bc8 ] [more precise X11 deps Don Stewart <dons(a)galois.com>**20081011211930] [TAG 1.4.3 Spencer Janssen <spencerjanssen(a)gmail.com>**20080921082528] [Bump version to 1.4.3 Spencer Janssen <spencerjanssen(a)gmail.com>**20080921054954] [getCommand Marco Túlio Gontijo e Silva <marcot(a)riseup.net>**20080712154521] [X implementation dependent keysyms from X.org zythmer(a)gmail.com**20080528004224 Added all of the X keysyms from X.org except the groups XK_MISCELLANY and XK_LATIN1 as well as skipped XK_VoidSymbol since it is not in any group. The above groups and symbol are already in Graphics.X11.Types ] [Make sure both --with-xinerama and --without-xinerama works Lennart Kolmodin <kolmodin(a)gentoo.org>**20080524112224 Use the builtin variable with_xinerama instead of our want_xinerama. This gives us ability to use both --with-xinerama and --without-xinerama. ] [Use -auto-all when profiling Don Stewart <dons(a)galois.com>**20080413112039] [Update configure.ac with new version number Lennart Kolmodin <kolmodin(a)gentoo.org>**20080331184021] [Add setKeyEvent to Graphics.X11.Xlib.Extras Jérémy Bobbio <lunar(a)debian.org>**20080328214753] [TAG 1.4.2 Spencer Janssen <sjanssen(a)cse.unl.edu>**20080327193813] [Bump version number to 1.4.2 Spencer Janssen <sjanssen(a)cse.unl.edu>**20080327193755] [Handle a NULL retrun from XGetWMHints correctly, fixes a segfault bug Spencer Janssen <sjanssen(a)cse.unl.edu>**20080327192702] [update version info Don Stewart <dons(a)galois.com>**20080307190921] [comments Don Stewart <dons(a)galois.com>**20080307190910] [Remove -O2 from ghc-options Spencer Janssen <sjanssen(a)cse.unl.edu>**20071216001612] [TAG 1.4.1 Spencer Janssen <sjanssen(a)cse.unl.edu>**20071211042441] [Bump version to 1.4.1 Spencer Janssen <sjanssen(a)cse.unl.edu>**20071211042430] [Check the return value of XGetWindowProperty, this fixes crash bugs when the requested Window/Property does not exist Spencer Janssen <sjanssen(a)cse.unl.edu>**20071211041940] [Update installation instructions to use newer Cabal's --configure-option Alec Berryman <alec(a)thened.net>**20071120214634] [Remove obsolete INSTALL file; installation instructions are in README Alec Berryman <alec(a)thened.net>**20071120203353] [Remove redundant XIconifyWindow binding Spencer Janssen <sjanssen(a)cse.unl.edu>**20071208084849] [Added haddock docs to setErrorHandler; added XIconifyWindow and XMapRaised bindings hoelz(a)wisc.edu**20071202043806] [use a working header file for XSetErrorHandler Lukas Mai <l.mai(a)web.de>**20071129174529] [Implemented a full binding to XSetErrorHandler hoelz(a)wisc.edu**20071127011847] [TAG 1.4.0 Don Stewart <dons(a)galois.com>**20071125032528] [bump X11 version to 1.4.0 Don Stewart <dons(a)galois.com>**20071125032135] [add copyright info and year for Graphics/X11/Xlib/Extras.hsc Don Stewart <dons(a)galois.com>**20071121024752] [bump to snapshot tag Don Stewart <dons(a)galois.com>**20071111200531] [Fix bug in the type of functions dealing with properties Mats Jansborg <mats(a)jansb.org>**20071101190154 The documentation for XGetWindowProperty and XChangeProperty states that the data must be represented as an array of char, short and long for a format of 8, 16 and 32 respectively. Previously Word8, Word16 and Word32 were used, resulting in bugs on platforms where char is not 8 bits, short 16 bits and long 32 bits wide. ] [home instead of $USER Don Stewart <dons(a)galois.com>**20071101212016] [space in CPPFLAGS will break .buildinfo file Don Stewart <dons(a)galois.com>**20071031172720] [add CPPFLAGS and LDFLAGS to buildinfo file Don Stewart <dons(a)galois.com>**20071031172436] [formatting Don Stewart <dons(a)galois.com>**20071031171257] [license header for Xinerama Don Stewart <dons(a)galois.com>**20071031165900] [untabify Don Stewart <dons(a)galois.com>**20071031165743] [#!-able Setup.lhs Don Stewart <dons(a)galois.com>*-20071030173235] [bump version Don Stewart <dons(a)galois.com>**20071030213949] [Bump version number Ian Lynagh <igloo(a)earth.li>**20071027124814] [#!-able Setup.lhs Don Stewart <dons(a)galois.com>**20071030173235] [TAG X11-1.3.0 Don Stewart <dons(a)galois.com>**20071030172832] [wall police Don Stewart <dons(a)galois.com>**20071030171430] [cabal tweaks Don Stewart <dons(a)galois.com>**20071030171341] [wall police Don Stewart <dons(a)galois.com>**20071029205511] [Bug fix: not storing height in XSizeHints.resize_inc Don Stewart <dons(a)galois.com>**20071029202844] [-Wall police Don Stewart <dons(a)galois.com>**20071029202542] [clean up warnings Don Stewart <dons(a)galois.com>**20071029201214] [wrong header included, hidden by -fasm Don Stewart <dons(a)galois.com>**20071029184208] [no .lhs Setup script Don Stewart <dons(a)galois.com>**20071029183618] [Xutils.h -> Xutil.hs Don Stewart <dons(a)galois.com>**20071029183435] [more info in readme Don Stewart <dons(a)galois.com>**20071029182528] [more typos in the merged .cabal file Don Stewart <dons(a)galois.com>**20071029182349] [duplicate line in .cabal file Don Stewart <dons(a)galois.com>**20071029181942] [Merge in X11-extras package, bump to 1.3.0. Adds Xinerama and X event support. Don Stewart <dons(a)galois.com>**20071029175855] [TAG 1.2.3 Don Stewart <dons(a)galois.com>**20071012181748] Patch bundle hash: c2047a1dad296b9bf634a852c71d6e5002226576

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Proposal (Trac ticket #3524): Add mfilter to Control.Monad
by Jon Fairbairn 01 Oct '09

01 Oct '09

Following on from the discussion of #3453, I propose the addition of mfilter to Control.Monad. It's just List.filter for any MonadPlus. I'd rather that we didn't have List.filter, and called this filter, but (a) I can't see that happening and (b) the naming scheme for Control.Monad is quite explicit. Time limit for discussion: 1 October. -- Jón Fairbairn Jon.Fairbairn(a)cl.cam.ac.uk

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