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  • Solution2.html
    parent s = father s `mplus` mother s grandparent s = paternalGrandfather s `mplus`
    561 bytes (71 words) - 08:43, 9 April 2021
  • Solution3.html
    parent s = (maybeToList (mother s)) ++ (maybeToList (father s)) grandparent s = (maybeToList (paternalGrandfather s)) ++
    631 bytes (63 words) - 08:44, 9 April 2021
  • Stateful nondeterminism
    newtype SuperState s t a = SuperState { runSuperState :: (s -> t -> (t,[(a,s)])) } instance Monad (SuperState s t) where
    1 KB (169 words) - 05:31, 9 March 2021
  • Ko/adjoint
    newtype State s a = State { runState :: s -> (a, s) } * <hask>s -></hask>
    380 bytes (24 words) - 12:26, 6 December 2023
  • Solution4.html
    parent s = (toMonad (father s)) `mplus` (toMonad (mother s)) grandparent s = (toMonad (parentalGrandfather s)) `mplus`
    1 KB (151 words) - 08:45, 9 April 2021
  • Solution1.html
    maternalGrandfather s = return s >>= \ms ->
    1 KB (147 words) - 08:41, 9 April 2021
  • New monads/MonadSupply
    newtype SupplyT s m a = SupplyT (StateT [s] m a) newtype Supply s a = Supply (SupplyT s Identity a)
    1 KB (202 words) - 05:09, 4 April 2014
  • All About Monads/Solutions
    maternalGrandfather s = return s >>= \ms ->
    4 KB (454 words) - 02:33, 7 January 2022
  • Haskell Quiz/FizzBuzz/Solution Syzygies
    xor s t = if null s then t else s loop n s = cycle $ replicate (n-1) [] ++ [s]
    980 bytes (157 words) - 15:19, 6 February 2021
  • Unix tools/Date
    [s] <- getArgs putStrLn $ formatCalendarTime defaultTimeLocale s time
    543 bytes (78 words) - 15:19, 6 February 2021
  • Algorithmic information theory
    ...e writings on the relevance of algorithmic information theory, and Chaitin's thoughts of its relatedness to epistemology, biology. [[Chaitin's construction]].
    440 bytes (57 words) - 06:23, 4 February 2016
  • Binary IO
    It's very simple to use, and provides a highly efficient, pure interface * JeremyShaw's update of HalDaume's NewBinary package (Cabalized): http://www.n-heptane.com/nhlab/repos/NewBina
    2 KB (254 words) - 19:03, 23 October 2013
  • Literate programming/Bird conversion via sed
    s/^> // s/\(\n\)> /\1/g
    600 bytes (99 words) - 10:10, 7 November 2013
  • 99 questions/Solutions/33
    ...e the prelude function for computing gcd's along with a test of the result's equality to one.
    329 bytes (49 words) - 19:43, 18 January 2014
  • Diagrams/Dev/ReleaseAutomation
    .../github.com/bergey/diagrams-stow/blob/master/release/UpperBounds.hs Daniel's]) This page has ideas & requirements for building a less ad-hoc tool, whic Either Brent's tool or Daniel's (or both) performs each of the tasks listed above. In some cases the code
    2 KB (241 words) - 16:19, 22 June 2015
  • Alternatives and extensions for libraries
    ...n if it is (mostly) backward-compatible, and otherwise in the "alternative(s)" column. !Module(s)
    5 KB (633 words) - 15:16, 6 February 2021
  • Iteratee
    Page about the implementation of Oleg's Iteratee maintained by John Lato. * [http://okmij.org/ftp/Haskell/Iteratee Oleg's Original Implementation]
    2 KB (228 words) - 15:18, 6 February 2021
  • BayHac2017/Karya
    ...e hackathon on Friday and Saturday, and possibly Sunday afternoon if there's interest. To get sound you'll need VSTs, a VST host, and jack if it's linux. It's
    886 bytes (153 words) - 22:47, 5 April 2017
  • Web/Existing software
    ! Author(s) ! Maintainer(s)
    4 KB (491 words) - 10:14, 3 August 2015
  • Unsafe functions
    * <hask>unsafeInterleaveST :: ST s a -> ST s a</hask> * <hask>unsafeIOToST :: IO a -> ST s a</hask>
    1 KB (206 words) - 12:27, 8 June 2023
  • 99 questions/Solutions/49
    gray n = foldr (\s acc -> ("0" ++ s):("1" ++ s):acc) [] $ gray (n-1) gray' n = (gl . gr) [] where gl y = foldr (\s acc -> ('0':s):acc) y gp
    2 KB (298 words) - 03:02, 7 June 2021
  • 99 questions/Solutions/34
    (**) Calculate Euler's totient function phi(m). Euler's so-called totient function phi(m) is defined as the number of positive inte
    1 KB (224 words) - 19:44, 18 January 2014
  • Diagrams/GSoC
    ...nd raise the profile of the Haskell programming language. Most of all, it's fun---you get to tangibly experience your contributions in the form of beau
    1 KB (165 words) - 22:48, 5 March 2014
  • 99 questions/Solutions/94
    ...hs using graph canonization. It is somewhat of a slow solution, taking >10 s to run <hask>regular 6 3</hask>. [i : s | i <- n, s <- xs, i `notElem` s, asc (i : s)])
    2 KB (388 words) - 03:47, 10 January 2017
  • State Monad
    Because (State s) forms a monad, values can be combined with (>>=) or do{}. ...is a function from initial state s to final value a and final state s: (a,s). These are usually wrapped, but shown here unwrapped for simplicity.
    7 KB (1,055 words) - 15:06, 21 December 2018
  • Programming performance/Yasuo Common Lisp
    2007-03-01 closing=1403.17 change%=-0.25944346 cash=12389.992 assets=(#S(PURCHASE :AMOUNT 0.9840075 :ORIGINAL-PRICE 1399.04)) 2007-03-02 closing=1387.17 change%=-1.1402752 cash=12389.992 assets=(#S(PURCHASE :AMOUNT 0.9840075 :ORIGINAL-PRICE 1399.04))
    3 KB (309 words) - 16:40, 6 February 2015
  • Blog articles/Functional programming
    .../notes-on-haskell.blogspot.com/2007/02/whats-wrong-with-for-loop.html What's wrong with for loops] ...blogspot.com/2007/02/whats-wrong-with-for-loop-revisited.html More on what's wrong with for loops]
    2 KB (160 words) - 08:56, 16 April 2020
  • The Monad.Reader/Issue4
    This month's editorial is an encouragement to join the [http://www.haskell.org/mailman/l ...y, for example c2hs, Knit, and other projects require C parsers, but there's no common code base. Since parsers are one of the killer features of Haskel
    2 KB (241 words) - 22:48, 25 March 2017
  • Wadlers Law
    #redirect [[Wadler's Law]]
    61 bytes (8 words) - 12:43, 8 June 2023
  • Poor Man's Heredoc in Haskell
    #redirect [[Poor man's here document]]
    73 bytes (10 words) - 11:48, 8 June 2023
  • Knight's Trevails
    #REDIRECT [[Haskell Quiz/Knight's Travails]]
    79 bytes (10 words) - 06:56, 8 June 2023
  • Haskell Quiz/Knight's Trevails
    #redirect [[Haskell Quiz/Knight's Travails]]
    79 bytes (10 words) - 06:31, 8 June 2023
  • Don's Config.hs
    #redirect [[Xmonad/Config archive/Don's Config.hs]]
    86 bytes (12 words) - 04:31, 8 June 2023
  • Xmonad/Config archive/Lee Aylward's xmonad.hs
    #REDIRECT [[Xmonad/Config archive/leedo's xmonad.hs]]
    88 bytes (12 words) - 13:01, 8 June 2023
  • Xmonad/Config archive/Devin's Config.hs
    #redirect [[Xmonad/Config archive/twifkak's Config.hs]]
    90 bytes (12 words) - 12:56, 8 June 2023
  • Xmonad/Config archive/Gwern's Config.hs
    #redirect [[Xmonad/Config archive/Gwern's xmonad.hs]]
    88 bytes (12 words) - 13:01, 8 June 2023
  • Cabal/NewBuild
    ...mation about <code>cabal new-build</code>, the main entry point into Cabal's new Nix-style local builds facility. * Haskell at Work's [https://haskell-at-work.com/episodes/2018-05-13-introduction-to-cabal.html
    592 bytes (78 words) - 15:19, 6 February 2021
  • Haskell Platform
    == What's in the platform ==
    2 KB (260 words) - 13:28, 21 January 2020
  • Xmonad/Config archive/droundy's Config.hs
    #redirect [[Xmonad/Config archive/David Roundy's Config.hs]]
    95 bytes (13 words) - 13:00, 8 June 2023
  • LensBeginnersCheatsheet
    [http://hackage.haskell.org/package/lens Edward Kmett’s <code>lens</code> package]. ''“JQuery for Haskell values”.'' ...s.Setter] ||<code>over setter f s</code> ||<code>setter %~ f $ s</code> ||modify pure value
    5 KB (742 words) - 19:22, 22 May 2022
  • Xmonad/Config archive/Thomas ten Cate's monad.hs
    #redirect [[Xmonad/Config archive/Thomas ten Cate's xmonad.hs]]
    98 bytes (14 words) - 13:00, 8 June 2023
  • Recursion in a monad
    monadic <hask>do</hask>-block. Here's some quick examples: s <- foldM fn [] [1..n]
    986 bytes (142 words) - 15:18, 6 February 2021
  • Worker wrapper
    revWorker s [] = s revWorker s (x:xs) = revWorker (x:s) xs
    2 KB (333 words) - 12:44, 4 June 2018
  • HaskellImplementorsWorkshop/2013/Farmer
    ...being used in the wild, and discuss lessons learned about working with GHC's plugin mechanism. HERMIT is being used to optimize SYB traversals, to fuse Stream Fusion's concatMap combinator, and to implement staged compilation within GHC to gen
    1 KB (174 words) - 06:36, 16 September 2013
  • Xmonad/Config archive/gray hemp's .conky cpu
    echo ${cpu} | gdbar -s v -h 15 -sw 1 >> /tmp/.dzen2cpugraph echo ${cpu cpu1} | gdbar -s p -w 7 -nonl
    924 bytes (169 words) - 15:18, 6 February 2021
  • Xmonad/ghci
    ...in xmonad from ghci's main thread is another option, which requires xmonad's code to be modified slightly:
    1 KB (163 words) - 20:37, 8 February 2015
  • 99 questions/Solutions/82
    end s = (last s == n) && (length s /= 1)
    1 KB (153 words) - 06:29, 31 July 2021
  • Denotative
    where search :: STArray s Vertex Bool -> [Vertex] -> ST s [Tree Vertex]
    4 KB (488 words) - 04:24, 5 April 2024
  • BayHac2017/presentations/requested
    Here's how Haskellers responded to the following question in the Call for Particip * Any, but I'd especially like to help people improve docs if that's welcome.
    1 KB (145 words) - 18:33, 27 January 2017
  • MapReduce as a monad
    *All of the guts of MapReduce are hidden in the monad's <hask>bind</hask> function a -> ([(s,a)] -> [(s',b)])
    6 KB (1,053 words) - 03:27, 9 April 2021
  • Diagrams/GHC7.6
    ...to install diagrams of course cabal rejects the latest version. But here's where things go screwy: cabal then starts looking back in time to try to fi
    1 KB (207 words) - 15:18, 6 February 2021
  • The Monad.Reader/Issue2
    ...ages.inf.ed.ac.uk/wadler/index.html#links Links] language and Steele et al's [http://lambda-the-ultimate.org/node/view/673 Fortress] language are effort ...patibility, exploring dark corners of [[GHC]], [[domain specific language]]s, and the [[Foreign Function Interface]].
    2 KB (239 words) - 22:47, 25 March 2017
  • Sample Programs for Learning
    * [[Bresenham's line drawing algorithm]]
    226 bytes (25 words) - 01:10, 26 April 2021
  • QuickCheck / GADT
    ...sed algebraic datatype|GADTs]]. One solution is to use [[existential type]]s. The example here is a solution to one of the exercises in Fun with [[phant compress (RPair s t) (x,y) = compress s x ++ compress t y
    8 KB (1,072 words) - 18:32, 16 January 2017
  • Ireland HUG
    ...uncements regarding the provisional (as of Jan. 2012) Ireland Haskell User's Group will be posted here.
    247 bytes (34 words) - 15:19, 6 February 2021
  • Xmonad/Config archive/thoughtpolice's xmobarrc
    , Run Com "uname" ["-s","-r"] "" 36000 , Run Date "%a %b %_d %Y %H:%M:%S" "date" 10
    1,023 bytes (104 words) - 15:18, 6 February 2021
  • Concurrency demos/Zeta
    This little piece of code computes an approximation of Riemann's zeta function, balancing the work to be done between N threads. zetaRange s (x,y) = [ fromIntegral n ** (-s) | n <- [x..y] ]
    4 KB (555 words) - 10:58, 22 June 2021
  • 99 questions/Solutions/32
    ...ne the greatest common divisor of two positive integer numbers. Use Euclid's algorithm. ...for ours. The function gcd' is a straightforward implementation of Euler's algorithm, and myGCD is just a wrapper that makes sure the arguments are po
    777 bytes (117 words) - 19:42, 18 January 2014
  • Impredicative types
    ...ent and return a result of that type". All universal quantifiers ("for all"s) must appear at the beginning of a type. ...e, even inside normal datatypes like lists or <tt>Maybe</tt>. The GHC User's Guide gives the following example:
    2 KB (347 words) - 11:46, 4 February 2023
  • Simple Unix tools
    This is intended as a beginner's tutorial for learning Haskell from a "Let's just solve things already!" point of view. The examples should
    6 KB (842 words) - 05:27, 8 February 2016
  • Idiom brackets
    Since f is not a pure function, it's f :: x -> y -> m c. The correct form would be instance Idiomatic i f g => Idiomatic i (s -> f) (i s -> g) where
    2 KB (365 words) - 18:50, 19 September 2017
  • ListT done right alternative
    instance (MonadReader s m, Functor m) => MonadReader s (ListT m) where instance (MonadState s m, Functor m) => MonadState s (ListT m) where
    2 KB (402 words) - 06:31, 12 May 2015
  • BayHac2014/DenotationalDesign
    ...conal/talk-2014-bayhac-denotational-design/blob/master/README.md this talk's README on GitHub].
    298 bytes (41 words) - 05:35, 23 May 2014
  • Smart constructors
    This has a problem however, that the [[constructor]]s of type ''Resistor'' are data S a = S a
    9 KB (1,351 words) - 18:21, 6 June 2020
  • Roll your own IRC bot/Source
    ...e uncompilable). That page already has source for the bot anyway, so there's not much point in keeping this separate one.
    284 bytes (52 words) - 00:57, 17 June 2015
  • Case comprehensions
    but when it's used in case expressions: Could the GHC example benefit from some more list-comprehension syntax? Let's borrow a new reserved word:
    6 KB (743 words) - 02:12, 5 August 2021
  • Anonymous function
    ...ight look like this: <hask>\x -> x + 1</hask>. (That backslash is Haskell's way of expressing a &lambda; and is supposed to look like a Lambda.) .../ foldr</hask>. So if I wanted to add one to each element of a list, here's one way to do it (without anonymous functions):
    2 KB (296 words) - 06:56, 12 April 2021
  • 99 questions/Solutions/96
    identifier s = identifier' s 'l' identifier' (c:s) t = (match c t) && or [identifier' s b | (a, b) <- fsm, a == t]
    2 KB (346 words) - 03:47, 10 January 2017
  • Foldl as foldr alternative
    ...ve, however, is the ''wrong one'' for what we're trying to do here. So let's change the order of the arguments of the helper: Believe it or not, we're almost done! How is that? Let's parenthesize a bit for emphasis:
    5 KB (891 words) - 14:21, 3 January 2018
  • Let vs. Where
    f :: s -> (a,s) f :: State s a
    4 KB (716 words) - 07:41, 26 January 2019
  • Performance/Monads
    newtype DRMonad e s w a = DRMonad {runDRMonad :: s -> (Either e a,s,w)} instance (Monoid m, Error e) => Monad (DRMonad e s w) where
    6 KB (995 words) - 23:51, 16 April 2021
  • Extensible datatypes
    Here's a simple test for object orientation (for some reasonable definition): ...Haskell's <tt>[[Dynamic]]</tt>, where you only have to deal with <tt>B</tt>s that are instances of <tt>Typeable</tt>. But even with that, note that <tt>
    4 KB (587 words) - 11:16, 28 March 2018
  • ZuriHac2015/Projects
    ...GPU's. It's about unsupervised machine learning. Later: Convolutional RBM's. || Markus Liedl || BSD3 || https://github.com/haskell-munich/accelerate-rb
    3 KB (355 words) - 14:25, 30 May 2015
  • Applications and libraries/Hardware verification
    ...Moreover it is able to interface with third party EDA tools such as Altera's [http://www.model.com/ Modelsim] and [http://www.altera.com/products/softwa :David J. King and John O'Donnell's digital circuit simulator
    2 KB (333 words) - 11:47, 4 November 2014
  • GHC/QualifiedModuleExport
    The following is a list of previous documents and discussions about Haskell's module system: * Iavor S. Diatchki et al's formal specification of the Haskell 98 module system: http://purely-functio
    3 KB (368 words) - 22:21, 24 February 2016
  • GHC/TypeSigsAndAmbiguity
    ...fine, but alas not always. Perhaps this is a deficiency in GHC, but here's one way it can happen: What's going on? GHC knows, from the type signature that <tt>x::a</tt>. Then appl
    4 KB (716 words) - 11:30, 24 January 2016
  • Burton-style nondeterminism
    ...sing from the ordering of external events to a functional language. Burton's technique uses abstract values contained in an (theoretically) infinite str ...d with <code>contents</code> to retrieve the abstract <code>Decision</code>s for use by <code>choice</code>:
    2 KB (341 words) - 09:18, 22 February 2022
  • Hac φ/Attendees
    | Holiday Inn Express, Penn's Landing | Holiday Inn Express, Penn's Landing
    1 KB (190 words) - 14:59, 21 October 2016
  • 99 questions/Solutions/19
    ...convert the problem to the equivalent problem for n > 0 by adding the list's length to n. | otherwise = let (f,s) = splitAt n xs in s ++ f
    3 KB (474 words) - 20:35, 23 May 2021
  • Action
    * <code>ST s a</code>, the type of encapsulated-state actions. The condition that an action's effects only occur if performed prevents their use in otherwise-ordinary Ha
    3 KB (428 words) - 04:08, 12 April 2024
  • Type class
    For now we refer to Wikipedia's article about [http://en.wikipedia.org/wiki/Type_class type classes].
    322 bytes (46 words) - 10:06, 3 August 2015
  • Currying
    As an illustration, let's take the function <haskell>div :: Int -> Int -> Int -- which is actually But there's more going on here than immediately meets the untrained eye. It could be a
    4 KB (669 words) - 02:17, 3 November 2023
  • Humor/Dialogs
    Lazy Mom : Here's a credit card, Son. Just charge what you need. from myself. What's the use pretending I'm getting them from you?
    3 KB (445 words) - 15:19, 6 February 2021
  • GHC/Coercible
    toHTML s = MkHTML s fromHTML (MkHTML s) = s
    5 KB (887 words) - 06:53, 12 June 2023
  • Newtype
    ...hask> keyword with <hask>data</hask> and it'll still compile, indeed there's even a good chance your program will still work. The converse is not true, newtype State s a = State { runState :: s -> (s, a) }
    6 KB (1,007 words) - 15:57, 22 May 2016
  • Cont computations as question-answering boxes
    ...utation of type <code>Cont r s</code>. That's a bit brain-twisting, so let's think about how we might do it... ...is going to receive a question <code>q</code> about a value of type <code>s</code>, and has to answer it somehow.
    7 KB (1,253 words) - 23:34, 25 June 2021
  • Introduction to QuickCheck2
    Let's untangle that, and then test the referentially transparent isolation. Let's use QuickCheck. First we need an Arbitrary instance for
    8 KB (1,214 words) - 00:46, 23 October 2017
  • Darcs vs. Git
    = GHC's switch from darcs to git =
    571 bytes (77 words) - 18:50, 18 June 2014
  • 99 questions/Solutions/6
    Here's one to show it done in a fold just for the fun of it. Do note that it is le Here's one that does half as many compares:
    2 KB (320 words) - 00:08, 8 July 2019
  • Bowling
    Spare {frameScore=s} -> [[s-10]] Strike {frameScore=s,next=10} -> [[10],[s-20]]
    4 KB (555 words) - 15:19, 6 February 2021
  • Common Language Runtime
    ...S crew have made some good progress on creating a new target for GHC so it's doable at least. ...has proven that these can indeed be encoded with the current state of GHC's type features.
    2 KB (405 words) - 10:31, 9 February 2019
  • Difference list
    True, there's lot of right association, too, but bad enough. * Donald Bruce Stewart's [http://hackage.haskell.org/package/dlist difference list library]
    3 KB (421 words) - 16:40, 1 August 2018
  • 99 questions/Solutions/22
    Since there's already syntactic sugar for ranges, there's usually no reason to define a function like 'range' in Haskell. In fact, th
    1 KB (214 words) - 02:08, 5 April 2014
  • Diagrams/Dev/Migrate0.7
    ...ad use the <code>at</code> function to construct <code>Located Trail</code>s.
    2 KB (297 words) - 06:13, 3 August 2013
  • Syntactic sugar/Pros
    There's lot of advocacy at [[ThingsToAvoid/Discussion]] which may be moved to here.
    322 bytes (47 words) - 03:29, 14 August 2021
  • Stiri Ro/Haskell-2007
    8 iunie 2007 S-a primit de la domnul conf M. Gontineac stirea despre continuarea unor cerc ...subiecte de pe fiecare bilet s-au referit la Haskell. Toti studentii care s-au prezentat la examen au trecut cu succes examenul.
    3 KB (399 words) - 14:50, 18 February 2015
  • WxHaskell/Development/Debugging
    ...an error message and make a note of the exception code. Look at Microsoft's [https://msdn.microsoft.com/en-us/library/cc704588.aspx NTSTATUS values pag ...[https://www.gnu.org/software/gdb/ GNU debugger] to see the debug message(s).
    1 KB (221 words) - 23:10, 28 January 2016
  • Multi-parameter type class
    instance VarMonad (ST s) (STRef s) where ...
    1 KB (198 words) - 22:52, 21 July 2021
  • ThreadScope Tour/RTS
    s
    853 bytes (146 words) - 04:26, 26 April 2021
  • FFI Introduction
    Haskell's FFI is used to call functions from other languages (basically C at this poi ...] stuff. I could implement the whole tcgetattr / tcsetattr thing, but let's just turn ICANON on and off, so IO.getChar doesn't wait for a newline:
    2 KB (331 words) - 12:45, 17 February 2015
  • New monads/MonadExit
    instance MonadState s (ExitT e (State s)) where instance Monad m => MonadState s (ExitT e (StateT s m)) where
    4 KB (707 words) - 09:43, 9 December 2014
  • MonadFix
    ...ction in such as way as to feed the returned sum back into the parameter ''s'', and we will sneak the sum into the replaced tree! Example in ASCII art: 4 s
    10 KB (1,757 words) - 23:34, 24 July 2021
  • Web/Libraries/Templating
    ...ain goal is to provide you with fully type-safe templates. It uses Haskell's quasi-quoting facilities so that everything is checked at compile time. Unl | s.clover@gmail.com
    1 KB (193 words) - 04:57, 26 April 2021
  • Hdirect
    ...20100703013753/http://www.haskell.org/hdirect/user.html HaskellDirect user's manual] (HTML, in the Web Archive) :Describes HaskellDirect's features
    2 KB (253 words) - 18:19, 24 March 2015
  • Abstract data type
    Here's an example of a '''parameterized data type'''. isEmpty (StackImpl s) = null s
    5 KB (872 words) - 13:14, 2 September 2014
  • Quotes
    Oh like that's going to work. You'd be better off selling T-shirts that <oerjan> EvilTerran: no, it's for turning cotheorems into ffee.
    3 KB (561 words) - 02:55, 26 April 2021
  • Rubiks Cube
    == Rubik's Cube represented with faces == ...is a simple model for a [http://en.wikipedia.org/wiki/Rubik%27s_cube Rubik's Cube].
    8 KB (1,020 words) - 01:02, 23 September 2018
  • List comprehension
    [toUpper c | c <- s] where <hask>s :: String</hask> is a string such as <hask>"Hello"</hask>.
    5 KB (679 words) - 17:14, 4 February 2023
  • Gtk2Hs/Tutorials/ThreadedGUIs
    ...ere was little accurate info on how to do multithreaded GUI in gtk2hs. It's trivial. Events are run within GTK's own thread. There is no need for extra precautions when running event code.
    4 KB (613 words) - 21:06, 7 October 2014
  • GHC
    ...documentation below relates to ''using'' GHC. For documentation about GHC's internals and building GHC, head over to the [https://gitlab.haskell.org/gh ...rg/ghc/docs/latest/html/users_guide/index.html The User's Guide]: The User's Guide has all you need to know about using GHC: command line options, langu
    4 KB (626 words) - 14:08, 14 July 2020
  • ZuriHac2015/Projects/FRPGames
    ...gners to share assets. I tend to use SDL2 and 2D graphics, only because it's easier. You can also talk to the LambdaCube3D people and combine FRP and th ...ome to borrow (I only have one, you can bring your own if you want). There's online documentation and examples of how to use it.
    3 KB (578 words) - 15:24, 29 May 2015
  • 99 questions/Solutions/70
    return x = P $ \ s -> Just (x, s) P v >>= f = P $ \ s -> do
    7 KB (1,025 words) - 02:14, 23 July 2021
  • Enumerator and iteratee
    <hask>i</hask> is the type of the iteratee's input messages (or list elements) and <hask>o</hask> is a type of the outpu {- s = state -}
    6 KB (927 words) - 12:02, 19 April 2024
  • Frag
    Frag is described in Mun's 2005 undergraduate thesis, ...3D Games]. An AI system for Frag is described in Jayatheeban Soundararajan's 2007 undergrad thesis, also titled [http://www.cse.unsw.edu.au/~pls/thesis/
    3 KB (386 words) - 11:31, 5 May 2017
  • 99 questions/Solutions/85
    perm n = foldr (\x xs -> [i : s | i <- [1..n], s <- xs, i `notElem` s]) [[]] [1..n]
    2 KB (287 words) - 03:50, 10 January 2017
  • Wadler's Law
    Wadler's Law states that: Under these circumstances, Paul's ruling seems right: it is pointless
    4 KB (583 words) - 10:26, 26 December 2017
  • Disposing of dismissives
    * <code>freeSTRef :: STRef s a -> ST s ()</code> ...ssives like <code>hClose</code> and <code>finalizeForeignPtr</code>...here's an idea: adapt the techniques used for those other types and values, so the
    3 KB (431 words) - 04:31, 9 June 2022
  • Introduction to QuickCheck1
    Let's untangle that, and then test the referentially transparent isolation. Let's use QuickCheck. First we need an Arbitrary instance for
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  • Calitatea si inspectorul cozonacilor
    <!-- atravers: Perhaps there's an archived version you can use to restore it? (Remember to add the "Humor"
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  • Plainly partible
    * In Simon Peyton Jones's [[Books|The implementation of functional programming languages]] (section 9 ...with their concept implementation for a ''single-use'' variant of Hancock's unique-name supply, where each one can only be used once, if at all - from
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  • 99 questions/Solutions/37
    (**) Calculate Euler's totient function phi(m) (improved).
    373 bytes (58 words) - 19:46, 18 January 2014
  • Orphan instance
    ...you'd like to reuse that code for handling multiplication. But now, there's two definitions of Monoid Int! ...Revelation feature] of Modula-3 which causes similar problems like Haskell's type class instances
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  • Prelude extensions
    == Schönfinkel & Curry's amalgamation combinator, for Haskell == == Curry and Feys's paradoxical combinator, for Haskell ==
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  • Calling Haskell from C
    Here's how to do that. And that's it.
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  • Type variables instead of concrete types
    These functions can also be used for <hask>Integer</hask>s, Ok that's not possible, so just consider a <hask>State</hask> [[applicative functor]]
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  • Xmonad/Config archive/adamvo's xmobarrc
    , Run Com "uname" ["-s","-r"] "" 36000 , Run Date "%a %b %_d %Y %H:%M:%S" "date" 10
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  • GHC/Memory Management
    ...new value. But GHC is able to efficiently manage garbage collection, so it's not uncommon to produce 1gb of data per second (most part of which will be Haskell's computation model is very different from that of conventional mutable langu
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  • Humor
    Who says functional programmers never have any fun? Here's some of the * HaskellWiki's [http://www.haskell.org/haskellwiki/QuotesPage QuotesPage]. E.g. a quotatio
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  • Backpack
    ...arately-typecheckable packages on top of a weak module system like Haskell's. The design of Backpack is inspired by the MixML module calculus of Rossber ...U Backpack to Work: Towards Backpack in Practice] (video, NYC Haskell User's Group)
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  • MonadPlus reform proposal
    ...an an mzero, except the string argument; indeed, so far as I know <tt>fail s</tt> is just mzero for any MonadPlus. MonadPlus is also barely made use of ...e does satisfy Left Catch, but it seems almost like that's only because it's such a simple monad (holding only one value). It is a useful observation t
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  • Rational
    ...represent rational numbers exactly as the ratio of two <hask>Integer</hask>s. Applying <hask>toRational</hask> to an <hask>Integral</hask> number <hask
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  • WxHaskell/Download
    ...kell-bin-i386-mac2.8.4-ghc6.10.4-0.11.1.2-0.dmg] (MacOS X, Intel, (Leopard's) pre-installed wxWidgets, ghc 6.10.4, updated)<br /> ...kell-bin-i386-mac2.8.4-ghc6.10.3-0.11.1.2-0.dmg] (MacOS X, Intel, (Leopard's) pre-installed wxWidgets, ghc 6.10.3, updated)<br />
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  • Monk upgrade
    ...ell.org (aka haskell.galois.com; aka monk) is in need of an OS upgrade. It's currently running Debian ''sarge''; the upgrade will be to ''etch'', the cu ## Rollback plan(s)
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  • Xmonad/Config archive/Gwern's xmonad.hs
    ...xK_Print), unsafeSpawn "import -quality 90 -descend png:$HOME/xwd-$(date +%s)$$.png") ...[[:blank:]]\\+/ /g' > $TMP && screen -S 'irssi' -X readbuf $TMP && screen -S 'irssi' -X paste .;rm $TMP")
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  • 99 questions/Solutions/99
    together (w,s) = zip (siteCoords s) w solve' words (s:ss) = if null possWords
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  • O'Haskell
    * [http://okmij.org/ftp/Haskell/HList-ext.pdf Haskell's overlooked object system] (PDF) -- Object oriented concepts in pure Haskell
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  • Fizzbuzz
    There's also a page [[Haskell Quiz/FizzBuzz]] with another solution.
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  • Random shuffle
    (a,s') <- liftM (randomR lohi) (readSTRef g) writeSTRef g s'
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  • 99 questions/Solutions/26
    -- The implementation first checks if there's no more elements to select, -- if so, there's only one possible combination, the empty one,
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  • Xmonad/Notable changes since 0.7
    ...esktop Environment Integration|basic desktop integration]], including ewmh's for taskbars and panels, gap toggling, and sensible desktop default key reb ...tp://braincrater.wordpress.com/2008/08/28/announcing-xmonad-light/ shepheb's xmonad-light], your package manager, or
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  • 99 questions/Solutions/40
    (**) Goldbach's conjecture. Goldbach's conjecture says that every positive even number greater than 2 is the sum o
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  • Xmonad/Config archive/Template xmonad.hs (darcs)
    If you want a good configuration to start from, it's quite simple. ...a <code>composeAll</code> for the <code>manageHook</code>, or use Haskell's <code>do</code> notation for most other hooks.)
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  • Uniqueness annotations for types
    Usually, this is all that's required - rarely is there a subsequent need to annotate the types (fixed o Could a similar annotation be made available for ''uniqueness''? Let's borrow a small piece of [https://clean.cs.ru.nl/Clean Clean] syntax:
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  • IO at work
    * it's a special file which seems to change anyway (e.g. terminal devices, named p ...the I/O of an ''action'' (<code>IO</code> computation) outside of Haskell's expression evaluation by moving it into the surrounding runtime system. The
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  • Haskell/Lazy evaluation
    ...ty list, and any Int. The 'any Int' part is fine, so we need to know if it's passed an empty list. Answering that question forces one step in the evalua Now it's clear that <code>getIt</code> has not been passed an empty list, since the
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  • Bluetile
    time is the most limited resource among the majority of users. It's good if you can configure a software in every respect. It's better if you
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  • UnicodeByteString
    ...ing track of strings encoded as raw bytes stored in <hask>ByteString</hask>s. Using functions such as <hask>length</hask> on a Unicode string just work ...ns to encode and decode Unicode strings to and from <hask>ByteString</hask>s are provided together with <hask>Data.List</hask> like functions.
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  • Partible laws
    * <i>S</i>(<code>T</code>) is the set of <i>basic definitions</i> for <code>T</cod ...u :: T</code>) means <code>u</code> isn't used elsewhere by a member of <i>S</i>(<code>T</code>);
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  • 99 questions/Solutions/31
    isPrime n = all ((/=0).mod n) $ 2:3:[x + i | x <- [6,12..s], i <- [-1,1]] where s = floor $ sqrt $ fromIntegral n
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  • Type signatures as good style
    Using explicit [[type signature]]s is good style and [[GHC]] with option <code>-Wall</code> warns about missin runST :: (forall s . ST s a) -> a
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  • Bottom
    ...'&amp;perp;' and in LaTeX as '\bot' (within math mode). In plain ASCII, it's often written as the extremely ugly character sequence '<code>_|_</code>'.
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  • Real World Haskell
    it's for short, script-like programs or large and demanding applications. * Learn about Haskell's compiler, interpreter, values, simple functions, and types
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  • Gtk2Hs/Tutorials/TreeView
    let s = head (head sel) v <- Model.listStoreGetValue list s
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  • Monomorphism by annotation of type variables
    <i>For the moment, this proposal can be "emulated" using Haskell's type classes:</i> :instance Monomo (ST s a)
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  • Monad Transformers Tutorial
    Clearly we want something like Maybe's <hask>(>>=)</hask> here to catch the Nothing, but instead of Maybe values a ...its result in MaybeIO then we just have to use runMaybeIO there, and that's it. What happens if we now have some "print" in between?
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  • Programming performance/ArthurVanLeeuwen Haskell
    getDay s = getDay' $ words s
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  • Infix expressions
    For ease of reference, here's their elegant solution: For completeness, here's the `dual':
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  • Applications and libraries/Bioinformatics
    ...and alignment processing -- see [http://malde.org/~ketil/biohaskell/ Ketil's bioinformatics] [http://www.ii.uib.no/~ketil/bioinformatics/ pages], and [h * [http://www.techfak.uni-bielefeld.de/ags/pi/ Robert Giegerich's group (AGPI) at Bielefeld University]
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  • Threepenny-gui
    ...localhost. Latency would be too high to use it as a web app. That said, it's perfectly stuitable for implementing multi-user apps on a local network, se * ... not a JavaScript or HTML library. It's a GUI framework with a Haskell API and abstracts many aspects of the docume
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  • Base package
    *[[Arrow]]s *[[Functor]]s
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  • First-class module
    Mark Shields and Simon Peyton Jones's [https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.15.9282&rep=rep1 Because it has also [[Dependent type]]s, it can leverage them so that it is not forced to have a separate module la
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  • New monads/MonadRandom
    liftState :: (MonadState s m) => (s -> (a,s)) -> m a cumulative = scanl1 (\(x,q) (y,s) -> (y, s+q)) xs -- cumulative weights
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  • Diagrams/Dev/Fixpoint
    <blockquote>It's important that this is NOT a newtype, so we can freely use the ...nym means we lose the <code>Functor</code> instance! Also, in the end, it's probably better that users do not need to know the underlying implementatio
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  • Monomorphism
    As an example, <hask>map</hask> is polymorphic. It's type is simply
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  • Concurrency with oracles
    ...been research into ''deterministic'' concurrency (e.g. Eleni Spiliopoulou's work with the Bristol Haskell system as described in his thesis [https://ci ...ions from the interface for the corresponding abstract data type. After it's used, an oracle remains constant - reusing it will not provide a "different
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  • 99 questions/31 to 41
    Use [http://en.wikipedia.org/wiki/Euclidean_algorithm Euclid's algorithm]. <div style="border-bottom:1px solid #eee">(**) Calculate Euler's totient function phi(m). <span style="float:right"><small>[[99 questions/So
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  • Context alias
    ...d on [http://repetae.net/recent/out/classalias.html a page on John Meacham’s website]. data N = Z | S N
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  • Parsing a simple imperative language
    First let's specify the name of the module: ...; ''S2'' | ''( S )'' | if ''b'' then ''S1'' else ''S2'' | while ''b'' do ''S''
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  • Haskell Lisp
    Lispers who love Haskell can be heard saying that Haskell is Lisp's missing [http://en.wikipedia.org/wiki/M-expression M-Expression] implementa ...binaries were available for Sparc systems running SunOS 4.1.2 and Sparc 10's (sun4m) running 4.1.3. In the last release, the full functionality of X win
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  • Humor/Erlkönig
    It's Haskell with his child Hank; "My son, it's a wisp of the outside world." -
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  • Referential transparency
    In formalizing this idea for programming languages, Søndergaard and Sestoft[[#notes|[2]]] conclude by saying informally, ...ator is referentially transparent if it preserves applicability of Leibniz’s law, or substitutivity of identity: the principle that any subexpression ca
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  • IO in action
    * if a function's result changes, it is <b>only</b> because one or more of it's arguments has changed. * [[Merely monadic]] provides more information about Haskell's implementation of the monadic interface.
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  • Computer science
    Wikipedia's [http://en.wikipedia.org/wiki/Computer_science Computer science]. Wikipedia's [http://en.wikipedia.org/wiki/Computability_theory Computability theory].
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  • BayHac2014/Prolog
    Here's the code for the whole unification function; you can probably remember each ...ost of the Prolog code from my talk and some comments to help explain what's going on and give you a few exercises to better understand logic programmin
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  • Euler problems/1 to 10
    sumStep s n = s * sumOnetoN (n `div` s) ...ximum [x | y<-[100..999], z<-[y..999], let x=y*z, let s=show x, s==reverse s]
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  • How to profile a Haskell program
    details Jeff's use of profiling to solve the problems. ...ckled data structures via Data.Binary. The XML part is generated by HaXml's DtdToHaskell. On a 54M XML file, the thing swaps like crazy and takes seve
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  • Darcs repositories
    ...s love to read code. That's how we get a feel for what a language is. Here's a list of significant Haskell projects, by serious Haskell programmers, wit
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  • GHCi in colour
    The prompt can be colored by altering GHCi's <code>prompt</code> setting including [https://en.wikipedia.org/wiki/ANSI_e :set prompt "\ESC[34m\STX%s > \ESC[m\STX"
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  • Seq
    While its name might suggest otherwise, the <code>seq</code> function's purpose is to introduce ''strictness'' to a Haskell program. As indicated b ...guity is undesirable, which is why <code>pseq</code> also exists (but that's another story).
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  • WxHaskell/Contribute
    ...So, idea is that implementing com support on top of wxWidgets and Haskell's com support. ; Add new PowerShell's install and building script for Windows platform
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  • 99 questions/Solutions/90
    This is easy to understand, but it's also quite slow, as it generates and tests N^N possible N-queen configurati If a list already contains two queens in a line, there's no point in considering all the possible ways of adding more queens.
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  • Netwire
    Netwire's FRP framework is intended to be used for continuous applications. It repla Netwire's underlying abstraction is more powerful than the [http://conal.net/papers/i
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  • Mlist
    A value of type: MList IO a represents a list of a's whose evaluation continually requires executing actions in IO.
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  • GHC/CloudAndHPCHaskell
    == Peter Braam's thoughts about HPC & Cloud Compute Frameworks == ...became the software and communication "standard", and more recently GPGPU's (which have CUDA and OpenCL) and other accelerators (FPGA boards are seeing
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  • GHC/Common Error Messages
    ''Remark that [[GHC]]'s type errors are not always in the right places should go here''
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  • Unamb
    The agreement precondition ensures unamb's referential transparency. See also the [[lub]] package, which extends unamb's usefulness with non-flat types.
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  • Type arithmetic
    Somewhat related is Lennart Augustsson's tool Hallgren's 2001 paper
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  • Monad/ST
    ST s α ...they return a value of type <code>α</code>, and execute in "thread" <code>s</code>. All reference types are tagged with the thread, so that actions can
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  • Tiny Identifier Dictionary
    ! Identifier(s) ! Identifier(s)
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  • Euler problems/21 to 30
    ...#24 you don't need to generate all the lexicographic permutations by Knuth's method or any other. -- The "x"s are different numbers
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  • Multiplate
    ...write two functions: <code>multiplate</code> and <code>mkPlate</code>. Let's define each of these functions in turn. That's it. Now we are ready to use out generic library to process our mutually rec
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  • GHC/Typed holes
    ...mes, when writing programs, we tend to use lots of polymorphic types. That's good! We can reuse those pieces, thanks to the types. But it can be difficu ...even say <tt>undefined</tt> is just a really crappy, useless hole!) But it's special in that when GHC encounters a hole during compilation it will tell
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  • Yampa/reactimate
    ...e>) for the signal function. If the second component of <code>sense</code>'s return value is <code>Nothing</code> then the previous sample is used again ...put sample previously provided by <code>sense</code>. <code>actuate</code>'s job now is to process the output (e.g. render a collection of objects conta
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  • Diagrams/Dev
    ...ell-style-guide/blob/master/haskell-style.md Coding style guidelines]. It's not worth being super picky about these, but in general they are quite good * byorgey's time spent hacking on diagrams:
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  • Piq
    '''Note''': Piq is not ready for use yet. It's waiting for [[Reactive]] to get into better shape.
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  • Eta conversion
    ...tp://www.haskell.org/pipermail/haskell-cafe/2010-December/087782.html What's the motivation for η rules?]
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  • Converting numbers
    There are special cases for converting from <hask>Integer</hask>s: as well as for converting to <hask>Integer</hask>s:
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  • Upgrading from MTL 1 to MTL 2
    ...l.org/package/transformers transformers] package. You may wish to check it's the same, so you can just delete it. ...rwise you need to generalize your instance to <hask>StateT</hask>. If that's not possible, you may need to introduce a <hask>newtype</hask>.
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  • AI/Genetic programming/Evolutionary chess
    ...dea of what it would look like to apply genetic programming to chess. Here's a non-technical overview I wrote a few months ago, sketching out some of my .... To be a little more technical about it than I was in that overview, here's some more haskell-ish ideas.
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  • LUI
    * Adapter -- Allows adapting an existing widget's model (with a Data.Accessor), image or size. To implement focus delegation, widgets simply merge the child widget's event map with their own event map however they see fit.
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  • AI/Genetic programming/GPLib
    6) <s>Cabalized Library distribution.</s> a) Should probably be split according to which type system(s)
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  • Installers
    ...mon file types for .lhs/.hs files will be known, and that the Haskell tool's handlers ("Open in Tool", "Edit with Tool", ..) will be available via the r ...the existing ones. But users need a chance to say no, and if they do, that's it.
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  • Haskell in web browser/Calc example
    In conclusion, let's finally develop a program that does something useful. As another "classical ...ities. Another (<code>dispmb</code>) will be used to update the calculator's display element.
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  • Xmonad/Installing xmonad
    $ pacman -S xmonad-contrib # for the xmonad core and contrib packages $ pacman -S xmonad # for just the xmonad core package
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  • DDC/ReleaseNotes-Alpha1
    * It's a bit slooow.. ...to the type graph. We'd likely get a big improvement by only loading what's needed for each particular program. [http://code.google.com/p/disciple/issu
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  • Failure
    Terminology is a little confusing. There's a few different things floating around: But what is a failure? It's any time that something does not succeed. Of course, this depends on your d
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  • Scoped type variables
    Scoped Type Variables are an extension to Haskell's type system that allow free type variables to be re-used in the scope of a ida :: a -> a -- This refers to a in the function's type signature
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  • 99 questions/Solutions/91
    -- Knight's tours on an nxn board ending at the given square -- Closed knight's tours on an nxn board
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  • Diagrams/Install/Install-cairo
    ...y (along with development headers) installed through your operating system's package manager or otherwise. After that, it should ''ideally'' be enough t ...ere are instructions] for installing gtk2hs on Windows. Note that Haskell's gtk package requires gtk+-2.x, not 3.x. gtk+-2.24 is the most recent in th
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  • Parallel/Glossary
    : A locked mutable variable that can be shared across Haskell threads. MVar's can be full or empty. When reading an empty MVar, the reading thread block == S-Z ==
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  • GPipe/Tutorial
    Let's walk our way through an simple example as I explain how you work with these ...splayed in the window. But before I explain <hask>FrameBuffer</hask>s, let's jump to the start of the graphics pipeline instead.
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  • GetOpt
    toSettingsH (Filter s:fs) i = toSettingsH fs (i { filter = s }) toSettingsH (DateFormat s:fs) i = toSettingsH fs (i { dateFormat = i= })
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  • Foldable and Traversable
    ...ce.html Data.Sequence] is recommended as an efficient alternative to [list]s, But many interesting <hask>Foldable</hask>s are also <hask>Functor</hask>s.
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  • High-level option handling with GetOpt
    Sven Panne's GetOpt module does a fine job at parsing command line options. It but rather how supplied options influence program's behaviour, how error
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  • XMonadContribTour
    ...or new users, but applied to the XMonad Contrib. Mainly because I think it's very difficult for newcomers to discover what extra features XMonad provide ...b/XMonad-Hooks-DynamicLog.html#v%3AdynamicLogWithPP DynamicLogWithPP] that's a DynamicLog with a Pretty Printer. The DynamicLog contrib module ships wit
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  • Questions and answers
    ...y the <hask>Show</hask> class is so damn weird...) Even so, I wonder if it's more efficient to join strings or use real I/O... [[User:MathematicalOrchid ...hs has some image handling routines. for pure image format libraries there's unfortunately a little less :(
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  • Generalised algebraic datatype
    and, similarly, S is similar to the combinator data Term = K | S | Term :@ Term
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  • Gentoo
    ...(presumably), more flexible, and we're more likely to maintain it since it's in a language we prefer and are more used to.
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  • Monad Transformers
    .... The monad <code>State s a</code> is only a type synonym for <code>StateT s Identity a</code>. Thus both <code>State</code> and <code>StateT</code> can
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  • Generics
    ...s to polymorphism in Java, which is confusingly called "generics". Haskell's polymorphism can often be erased at compile-time, similar to Java where the ...lementation is necessary, similarly to <hask>Show</hask>, for instance. It's described in a [[GHC.Generics|separate wiki page]].
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  • Safely running untrusted Haskell code
    ...own monadic type that is a restricted subset of <code>IO</code>). But it's a lot more complicated than that... == Verifying safety: lambdabot's approach ==
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  • 99 questions/Solutions/39
    This is good for ''very narrow ranges'' as Q.31's <code>isPrime</code> tests numbers by ''trial division'' using (up to<math> ...http://www.haskell.org/haskellwiki/99_questions/Solutions/31 31st question's solution] (instead of the above sieve of Turner), adjusted to start its mul
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  • Safe Haskell
    * <s>magic</s> <s>omnimiscent</s> [http://www.softpanorama.org/SE/quotes.shtml idiot-proof]. ...unsafe feature, the purpose is to use it to implement a safe API - if that's the case, all you have to do is add <code>Trustworthy</code> to your langua
    3 KB (471 words) - 03:00, 5 August 2021
  • Upgrading packages
    * [http://coldwa.st/e/blog/2017-09-09-Cabal-2-0.html What's new in Cabal/cabal-install 2.0 — improved new-build, Backpack, foreign li ...ownloads.haskell.org/~ghc/latest/docs/html/users_guide/index.html GHC User’s Guide]
    1 KB (182 words) - 20:19, 19 March 2018
  • 99 questions/Solutions/23
    ...the target list length is > (orig list / 2). Here's another solution that's efficient in the other way (target < (orig list / 2)) by constructing an ac
    4 KB (666 words) - 13:03, 10 May 2014
  • Shootout/Fannkuch
    Bertram's with a couple of refactors, a small let binding by Don, a new IO $ \s ->
    22 KB (3,539 words) - 00:49, 14 December 2016
  • Ce optiuni se folosesc la compilarea din linie de comanda?
    % ghc-6.8.2 -S Foo.hc
    779 bytes (123 words) - 15:18, 6 February 2021
  • Diagrams/Dev/Transformations
    ...ctor with a <math>1</math> as its <math>n</math>th entry and <math>0</math>s everywhere else. For example, ...f the matrix, as I claimed. It's also not too hard to see that the matrix's action on any other vector is completely determined by linearity. Finally,
    14 KB (2,245 words) - 03:01, 11 April 2015
  • Hac NYC/Talks
    ...and allows the calculation of quantities of physical interest. So far, it's mainly electromagnetic theory. | A brief account of a biologist's very pleasant experience with STM and Snap, for processing brain data and g
    2 KB (335 words) - 15:02, 5 April 2014
  • Humor/Wanda
    In his "Filmgoer's Companion", Mr. Leslie Halliwell helpfully lists four of the cinema's greatest moments which you should get to see if at all
    8 KB (1,343 words) - 09:02, 13 March 2016
  • Xmonad/Guided tour of the xmonad source/Core.hs
    These three record types make up the core of xmonad's state and configuration: * A value of type <hask>XState</hask> stores xmonad's mutable runtime state, consisting of the list of workspaces, a set of mappe
    13 KB (2,057 words) - 10:15, 28 September 2017
  • Sound data structures
    ...hask>, [[Storable Vector|StorableVector.Lazy a]], <hask>(StateT s Maybe a, s)</hask> (like {{HackagePackage|id=stream-fusion}})
    3 KB (353 words) - 23:01, 29 April 2014
  • Hack-Nix
    # The ways/base3.nix file let's you override and # In this example it's used to remove base >= 4 from the
    5 KB (726 words) - 10:39, 5 January 2018
  • Functional programming/Old version
    move d0,s let s = z-(x+y)
    2 KB (378 words) - 23:58, 5 April 2021
  • BayHac2017/CodeWorld
    ..., and casual games. In fact, I'm fairly comfortable saying that CodeWorld's collaboration API is the easiest way to build multi-player games in Haskell ...to jump in''' and work on more fundamental changes to CodeWorld, then here's a list of tasks of reasonable scope for a weekend.
    4 KB (593 words) - 01:45, 27 March 2017
  • Yhc/Javascript/Programmers guide/EchoCPS2 demo source
    -- The s argument is the string to output, and the c argument is putLine s mbb c = getHTMLDocument $ \doc ->
    4 KB (559 words) - 15:17, 6 February 2021
  • Floyd's cycle-finding algorithm
    ...ion of [http://en.wikipedia.org/wiki/Floyd's_cycle-finding_algorithm Floyd's cycle-finding algorithm] for finding cycles in lists.
    950 bytes (133 words) - 00:39, 5 February 2019
  • Functor-Applicative-Monad Proposal
    ...on] with [[Roles]]. Will "probably be fixed in the future", but for now it's off the table. ...k in 7.10.) To make 7.10 not complain about the then unrecognized flag, it's best to specify it in a CPP block,
    10 KB (1,557 words) - 11:46, 24 October 2015
  • Blog articles/Comparisons
    ...details-on-f-computation-expressions-aka-monadic-or-workflow-syntax.aspxF#'s monadic syntax] * [http://www.acooke.org/cute/ErlangsSyn0.html Small comparison of Erlang's syntactic difficulties]
    13 KB (1,443 words) - 23:42, 13 October 2019
  • GHC/Stand-alone deriving declarations
    ...-XUndecidableInstances</hask> to allow this instance declaration, but that's fair enough. GHC's "newtype deriving mechanism" (see [http://www.haskell.org/ghc/dist/current/
    5 KB (755 words) - 22:49, 12 June 2021
  • Stiri Ro/Haskell-2013
    Aparut prin eforturile grupului Ro/Haskell volumul s-a dovedit o alegere inspirata fiind inca din primele luni de folos. S-a incheiat setul de laboratoare de programare functionala si grafica in HOp
    2 KB (347 words) - 18:33, 24 July 2013
  • Xmonad/Screenshots
    Image:byorgey-config.png|Byorgey's dzen ...5073140/http://www.webframp.com/2009/01/06/xmonad-layout-gallery/ webframp's xmonad layout gallery] (archived; original page [http://www.webframp.com/20
    13 KB (1,464 words) - 02:28, 20 October 2014
  • Space leak
    It's frustrating to study about leak when the examples given no longer leak for
    1 KB (168 words) - 06:46, 4 February 2015
  • Benchmarks Game/Parallel/BinaryTrees
    -- more times the maximum residency)", as per GHC User's Guide: io s n t = printf "%s of depth %d\t check: %d\n" s n t
    6 KB (1,055 words) - 23:27, 18 April 2020
  • Kind
    newtype StateT s m a :: * -> (* -> *) -> * -> * ...>. GHC introduces another inhabited kind, <TT>#</TT>, for [[unlifted type]]s.
    2 KB (234 words) - 19:05, 28 September 2017
  • What a Monad is not
    ...pecific, it's IO that's impure. That makes the IO monad impure. But that's not a general property of monads - just IO. And even then, we can pretend t ...ly possible to abstract away explicit state passing by using a Monad, that's not what a monad is. Some examples for monads that are not about state: Ide
    6 KB (1,032 words) - 16:45, 2 December 2020
  • Monoid
    ...instances are really more natural than the other, so we use the [[newtype]]s <tt>Sum n</tt> and <tt>Product n</tt> to distinguish between them: ...orementioned [[Foldable]], or the [[Writer monad]], or some [[Applicative]]s). But for a rather striking example of what Monoid can do alone, you can lo
    7 KB (1,101 words) - 02:30, 27 December 2019
  • Applications and libraries/Database interfaces
    ...sely on Perl's DBI interface, though it has also been influenced by Python's DB-API v2, JDBC in Java, and HSQL in Haskell. Supports SQLite3, PostgreSQL, ...th the [http://www.haskell.org/haskellDB original version from Daan Leijen's] HaskellDB and the [https://github.com/m4dc4p/haskelldb HaskellDB more up-t
    5 KB (634 words) - 11:56, 17 July 2021
  • 99 questions/90 to 94
    ...ant to work on one of these, put your name in the block so we know someone's working on it. Then, change n in your block to the appropriate problem numb <div style="border-bottom:1px solid #eee">(**) Knight's tour. <span style="float:right"><small>[[99 questions/Solutions/91|Solution
    6 KB (802 words) - 06:27, 11 June 2023
  • GHC/AdvancedOverlap
    functional dependencies and overlapping instances, and that's what instance ShowPred Bool HTrue -- the same as Show's
    10 KB (1,575 words) - 13:27, 14 January 2015

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