Search results

• Performance/Monads
  ...line well and the library is in need of an optimization pass. As a result, it can often impose a performance hit of up to 300% (your code will run up to We can unroll it as follows:
  6 KB (995 words) - 23:51, 16 April 2021
• WxHaskell/Cygwin
  ...idgets also works without the mingw compiler, but all programs linked with it will fail mysteriously! ...t> to <tt>sh-org.exe</tt>. Next, make a copy of <tt>bash.exe</tt> and name it <tt>sh.exe</tt>.
  5 KB (902 words) - 19:36, 5 April 2015
• Darcs
  '''darcs''' is a peer-to-peer revision control system, written in Haskell. It is the standard RCS of the Haskell community. ...remove</tt>: add a change which empties the item and deletes it, but keep it as an unmanaged item.
  4 KB (654 words) - 15:20, 6 February 2021
• WxHaskell/Tips and tricks
  * read carefully [[WxHaskell/Quick start | Quick start]] - it contains more information than you think ...after version 0.90.1.0 of wxHaskell. However, to run wxHaskell inside ghci it may be necessary to pass the <code>-fno-ghci-sandbox</code> flag. ghci may
  3 KB (496 words) - 14:04, 4 October 2014
• Data.Semigroup
  ...>Monoid</hask>. The <hask>Monoid</hask> typeclass however does not enforce it's instances to already be instances of <hask>Semigroup</hask></div> <div>The <hask>Semigroup</hask> is a particularly forgiving typeclass in it's requirements, and datatypes may have many instances of <hask>Semigroup</h
  4 KB (688 words) - 22:51, 29 June 2021
• Yhc/Javascript/Programmers guide/EchoCPS2 demo source
  -- Line-mode output: create a <div> element, place a text in it, -- The "onkeypress" handler: it does all the job. Note the o argument:
  4 KB (559 words) - 15:17, 6 February 2021
• Diagrams/Dev/Fixpoint
  <blockquote>It's important that this is NOT a newtype, so we can freely use the <code>Rewrapped</code> instances for it anymore.</blockquote>
  7 KB (1,077 words) - 14:56, 12 June 2014
• Relational algebra
  ...s in Pointfree Functional Dependency Theory]. A concise and deep approach, it is [[pointfree]]. See also [http://www.di.uminho.pt/~jno/html/ the author's ...pper]]). Can <hask>Query</hask> be regarded as an [[arrow]], and if so, is it worth of doing so?
  4 KB (582 words) - 09:02, 15 April 2015
• What a Monad is not
  ...sed if you leave this page more confused than before. That just means that it has successfully destroyed your false assumptions, or that you've fallen fo ...t.wordpress.com/2009/01/31/reviving-the-gofer-standard-prelude-circa-1994/ It could be done differently and still work].
  6 KB (1,032 words) - 16:45, 2 December 2020
• 99 questions/Solutions/31
  Well, a natural number ''k'' is a prime number if it is larger than '''1''' and no natural number ''n >= 2'' with ''n^2 <= k'' i This one does not go as far as the previous, but it does observe the fact that you only need to check numbers of the form 6k +/
  3 KB (432 words) - 07:06, 11 May 2016
• Libraries and tools/MIME Strike Force
  It might also be nice if the combinators did not require a monadic interface. ...all the attachments, etc. In fact, a MTA might only care about RFC2822, so it should not have to be forced to deal with the rest of the layers added by a
  6 KB (930 words) - 05:25, 24 April 2021
• Mac OS X Common Installation Paths
  * Makes it easy for a user to locate all the Haskell components, especially user insta ...bles easy removal of a user installed package, whether they have installed it <tt>--user</tt> or <tt>--global</tt>.
  6 KB (862 words) - 05:34, 6 August 2014
• Real World Haskell
  it's for short, script-like programs or large and demanding applications. ...online, but the link is now dead. Please edit this if know where to find it.)
  3 KB (371 words) - 04:17, 14 August 2021
• GHC/Typed holes
  ...ic types. That's good! We can reuse those pieces, thanks to the types. But it can be difficult sometimes when writing a program to see how the polymorphi ...ce if we could have the compiler tell us the types of everything in scope? It'd be much easier to see how we can 'fit' them together like puzzle pieces.
  9 KB (1,711 words) - 20:19, 31 August 2014
• Terminator vs. separator
  Usually, we don't think much about it. ...insert them whereever you want. If you place every element at a line then it is easy to disable individual lines with a line comment (starting with <has
  3 KB (426 words) - 18:44, 4 October 2021
• Diagrams/Dev/Migrate1.2
  ...you have several options for replacing it, depending on how you were using it: * If you were just using it to get some lines to scale along with a diagram, use a <code>Local</code> l
  5 KB (807 words) - 19:36, 30 June 2014
• IO at work
  * it's a special file which seems to change anyway (e.g. terminal devices, named ...code> always yields the same result, for some built-in sense of equality), it could transform the program, calling the function more or less often, or ea
  8 KB (1,215 words) - 07:10, 12 June 2023
• Applications and libraries/Database interfaces
  : HDBC is modeled loosely on Perl's DBI interface, though it has also been influenced by Python's DB-API v2, JDBC in Java, and HSQL in H : This close integration makes it possible to do arbitrary computations on the database (like computing the t
  5 KB (634 words) - 11:56, 17 July 2021
• How to profile a Haskell program
  ...gather together the information contained in the case studies and present it here in reference form.'' ...o write a Haskell program]]. It's super easy, and you'll be happy you did it.
  7 KB (1,084 words) - 19:08, 3 February 2021
• Reactive-banana
  == What is it? == ...ns, [[Reactive-balsa|computer music]] or robot controllers. In particular, it promises to avoid the spaghetti code that is all too common in traditional
  5 KB (615 words) - 21:05, 4 January 2016
• Keyword arguments
  then be omitted. It is a type error to omit a required keyword argument.
  636 bytes (94 words) - 15:18, 6 February 2021
• Grapefruit
  ...al Reactive Programming]] (FRP) with a focus on user interfaces. FRP makes it possible to implement reactive and interactive systems in a declarative sty * a record system which makes it possible that
  5 KB (668 words) - 15:20, 16 February 2017
• Action
  ...ode> in your program. When your program is run, the I/O will be performed. It isn't possible to perform I/O from an arbitrary function, unless that funct <code>Main.main</code> is also an action, so it requires a context as well. But unlike <code>ST s a</code>, that is provide
  3 KB (428 words) - 04:08, 12 April 2024
• Applications and libraries/Graphics
  :Blobs is a diagram editor for directed graphs. It is written in Haskell, using the platform-independent GUI toolkit wxHaskell ...ray-tracers simulate global illumination and eliminates the ambient term. It does this using a set of random techniques to simulate an integration model
  8 KB (1,206 words) - 19:26, 11 December 2018
• Equational reasoning examples
  ...bout repeating or elaborating on these things. But what, if anything, does it mean in programming practice? ...e that the equational reasoning formalists have their own forums/pages;-). It is not necessary to copy the examples here, but your explanatory text shoul
  6 KB (833 words) - 00:02, 6 November 2021
• Non-strict semantics
  ...f any subexpression fails to have a value, the whole expression fails with it. ...is why people say that Haskell lets you write your own control structures. It's also one of the motivations behind Haskell being a [[pure]] language (tho
  9 KB (1,503 words) - 13:55, 15 December 2019
• Performance/Strictness
  ...the expression in the heap in a ''suspension'' (or ''[[thunk]]'') in case it is evaluated later. Storing and evaluating suspensions is costly, and unne ...example. Strictness analysis sometimes does wonderful things; for example it is very good at optimising <hask>fac</hask>:
  7 KB (1,162 words) - 17:16, 8 June 2022
• 99 questions/Solutions/39
  ...s list produced by sieve of Eratosthenes to which it refers internally. So it'll be slower, but immediate, testing the numbers one by one. ...rs the relevant range out. [But this way is very slow and I only presented it because I wanted to show how nicely the ''Sieve of Eratosthenes'' can be im
  5 KB (696 words) - 19:46, 18 January 2014
• GHC/Coercible
  ...but the type checker ensures that it really is safe to use it. If you use it illegally like in ...olvalble – the role annotation on <hask>Set</hask> prevents coercing under it, and the newtype unwrapping cannot be used as <hask>MkSet</hask> is not in
  5 KB (887 words) - 06:53, 12 June 2023
• Merely monadic
  * the ''time of composition'': when it is defined; * the ''time of execution'': when it is used;
  6 KB (988 words) - 04:35, 16 March 2021
• 99 questions/Solutions/26
  -- We don't actually need this base case; it's just here to A funny solution using Applicative in Control.Applicative. Funny because it's the opposite of other solutions.
  5 KB (659 words) - 19:40, 18 January 2014
• Haskell mode for Emacs/Color chords
  ...ng software. It is very rewarding on an immediate and personal level, but it will also certainly help us make better software.
  2 KB (249 words) - 22:40, 29 June 2021
• Closure
  ...]], is a function that makes use of [[free variable]]s in its definition. It 'closes' around some portion of its environment. for example
  566 bytes (92 words) - 13:53, 1 January 2017
• Budapest Hackathon 2016/Talks
  ...ell codebases. Then we will look into our extensive use of QuickCheck, how it's used and what we learned. ...Zeldspar is built on the top of a deep language stack, and I also show how it can be compiled to run efficiently on many-core devices such as Adapteva's
  4 KB (673 words) - 05:44, 26 October 2016
• Examples/Random list
  ...ts helper unpick' are strict in the entire list being operated on (forcing it all into memory at once). And IO [a] cannot lazily return any initial valu <hask>removeOne</hask> returns the output list lazily as soon as it has decided not to delete any element in a prefix of the input list.
  6 KB (855 words) - 12:54, 26 June 2017
• 99 questions/Solutions/28
  If you wanted to solve it without the <hask>comparing</hask> function, you could do: ...the problem (that is, lists appear in order of length frequency), although it does not give the same result as the example:
  4 KB (650 words) - 20:33, 27 August 2015
• Phantom type
  * it may help to [[No kind signatures|avoid kind signatures]] Phantom types are nearly always either <tt>newtype</tt> or <tt>data</tt>. It is possible to create "phantom type synonyms", but they are usually useless
  5 KB (868 words) - 06:40, 11 June 2021
• Diagrams/Dev/Arrows
  ...lection of "standard" arrowheads for the user to choose from. In addition it ought to be possible for the user to specify any diagram they like for use ...ght also want to have control over the middle of the arrow -- i.e. whether it curves, and if so how much and in which direction, etc.
  8 KB (1,340 words) - 13:19, 29 March 2014
• Hac φ/Talks
  <!--If you'd like to give a talk, announce it here; tell us your name, the title of the talk, a short description. Pleas
  672 bytes (111 words) - 21:42, 9 August 2016
• List of Projects that use Haskell
  ...often ask, «Okay, Haskell looks like a fun language; but what's written in it?» : Not necessarily «free as speech», but people should be able to try it out and look at the source code.
  2 KB (296 words) - 14:29, 24 February 2020
• Raspberry Pi
  '''Note:''' GHCi does not work on ARM with older versions, but it has become available in GHC 7.8. See [http://www.haskell.org/pipermail/hask ...and it may still be possible to install it in an experimental manner, but it is not (currently) available in the Debian Raspberry Pi repository. [http:/
  5 KB (701 words) - 18:13, 14 November 2020
• Cabal/How to install a Cabal package remotely
  Sometimes, it is difficult or inconvenient to set up the entire virtual server. You may find it much easier to get just a working
  3 KB (480 words) - 04:39, 24 April 2021
• ThreadScope
  Next, check out the user guide. We call it the [[ThreadScope Tour]]. ...esponds to an operating system thread. For each thread you can see whether it is running a Haskell thread or performing garbage collection. You can find
  6 KB (946 words) - 13:16, 4 September 2017
• Applications and libraries/Network
  ...cess of downloading TV Series from [http://www.mininova.org mininova.org]. It will scan your downloaded files to find out what your interests are and dow :Ginsu is a client for the gale chat system. It is designed to be powerful and above all stable, as well as having a quick
  6 KB (929 words) - 18:17, 31 August 2016
• Formatting function types
  functions seemed very strange to me: "Okay, we give it a handle, and get '' I aggree with the argument, that for beginners it is hard to see what a function returns, but that has to do with currying. A
  2 KB (363 words) - 08:15, 23 May 2021
• Language and library specification
  ...shed in July 2010, and is the current definition of the Haskell language. It is freely available online, in the following formats: * read it online: [http://www.haskell.org/onlinereport/haskell2010 The Haskell 2010 R
  7 KB (1,054 words) - 07:37, 12 June 2023
• Introduction to IO
  ...page is intended as a quick introduction to how IO is treated in Haskell. It doesn't describe everything there is to know, but should give some idea of ...first performs the action <code>x</code>, and captures its result, passing it to <code>f</code>, which then computes a second action to be performed. Tha
  5 KB (958 words) - 15:20, 3 August 2022
• Yhc/RTS/Exceptions
  ...and an exception handler. It runs the IO action and if an exception occurs it runs the exception handler. throw simply throws an exception. For example ...sulted from a call to the 'error' function then it does nothing, otherwise it rethrows the exception.
  8 KB (1,141 words) - 01:44, 14 July 2021
• Toolmaking libraries
  ...ntyped core around this language, after going over it with a comb to check it's adequately expressive?: ...hoices to note: this isn't a supercombinator language or a variant of ANF, it's an ordinary untyped lambda calculus with minimal extensions to capture pa
  5 KB (735 words) - 15:20, 6 February 2021
• Catch
  ...e/total total] package does not search for incomplete pattern matches, but it does allow you to write compiler-checked exhaustive pattern matches. [http: *[[Xmonad]]'s central StackSet.hs module has been checked repeatedly, as it has evolved. Unfortunately currently this module goes beyond Haskell 98, bu
  2 KB (353 words) - 08:17, 6 August 2015
• How to work on lists
  ...le, <hask>filter odd xs</hask> returns a list of ''odd'' numbers. That is, it deletes everything that is ''not'' odd. :Find or write a function to convert foo into bar, and then apply it to the whole list using <hask>map</hask>.
  6 KB (1,106 words) - 12:32, 15 November 2019
• Extensible record
  ...n of the Haskell-like language [http://www.cs.uu.nl/~daan/morrow/ Morrow], it is based on the concepts of the article. And [http://www.cs.uu.nl/~daan/pu ...tem allows field selection and dropping of fields using pattern matching. It also supports defaulting.
  6 KB (770 words) - 05:26, 10 December 2020
• Cxx foreign function interface
  ...ace to a C++ library using the "export C" declaration (in C++) which makes it look like a C library. This seems to be the standard technique for bridgin ...ng to C++, using the mangled C++ names directly without using "export C". It also suggests the possibility of a more automated approach using gcc-xml.
  4 KB (618 words) - 22:55, 11 July 2021
• AtomicMemoryOps
  ...s a thin layer over the basic operations: GHC primops or foreign primops. It does, as of version 0.4, provide some useful operations for end-users, incl ...o point at the new one. The problem with that approach in Haskell is that it can be very hard to provide the old pointer with any reliability, due to th
  5 KB (865 words) - 18:26, 21 November 2013
• IO in action
  * if a function's result changes, it is <b>only</b> because one or more of it's arguments has changed. * For those who prefer it, John Launchbury and Simon Peyton Jones's [https://citeseerx.ist.psu.edu/vi
  4 KB (674 words) - 07:12, 12 June 2023
• PermissiveImportsProposal
  ...t them as such. There's no way to take advantage of the current behaviour; it just causes fewer programs to be accepted than are necessary, and given we' ...ead of String-based) requires a certain amount of friction. In these cases it is common to use the same identifiers for the same functionality, but this
  9 KB (1,515 words) - 23:39, 23 October 2014
• BayHac2014/Prolog
  ...to see it again :)—you'll probably have a chance. I'll also try to improve it based on feedback I've gotten; if you have anything to say, please email me
  2 KB (410 words) - 11:26, 13 February 2019
• Means of expression
  It is generally good style to remember the rule: Thus it is not good style to comment intensively if the language provides primary w
  5 KB (765 words) - 22:40, 23 April 2021
• Conduit
  Conduits are an approach to the streaming data problem. It is meant as an alternative to [[Enumerator_and_iteratee|enumerators/iterato
  1 KB (138 words) - 02:42, 13 July 2019
• Emacs/Inferior Haskell processes
  ...skell, the option is called <code>haskell-program-name</code>. You may set it to <code>"/some/where/ghci.exe"</code> or even <code>"cabal-dev ghci"</code ...as part of the haskell-mode package, so there is nothing special to do for it. On some systems, you may need this in your .emacs:
  8 KB (1,358 words) - 17:26, 9 August 2019
• Hac φ/Projects
  If you need a place to host a project so that others can help with it, we suggest using [http://github.com github] with [https://git-scm.com/ git ...have a project that you want to work on at the Hackathon, please describe it here.
  2 KB (362 words) - 15:04, 21 October 2016
• Safely running untrusted Haskell code
  ...our own monadic type that is a restricted subset of <code>IO</code>). But it's a lot more complicated than that... ...lls out to [http://hackage.haskell.org/package/mueval mueval], which while it uses many of the same techniques, is structured differently.''
  5 KB (830 words) - 12:41, 22 June 2021
• Unary operator
  It is syntactic sugar for the <hask>Prelude.negate</hask> function and allows With it enabled, expressions like <hask>(n !)</hask> are parsed as <hask>((!) n)</h
  3 KB (397 words) - 20:54, 24 February 2024
• Web/Libraries/XML and HTML
  ...the XHTML package by being faster and having a convenient monad instance. It looks like this: ...L documents, including the DTD subset and the document subset, in Haskell. It contains an XML parser, an HTML parser, namespaces are supported, XPath exp
  6 KB (878 words) - 09:02, 26 March 2015
• WxHaskell/Mac
  ...ded, but if you want to do it anyway, download the source code and install it with the following flags <li>Now it's time to install the wxHaskell libraries proper:
  6 KB (793 words) - 17:25, 15 April 2018
• Command line option parsers
  | {{HackagePackage|id=argparser}} || - || None (though it depends on package containers, which uses extensions) || GHC 9.0 build succ ...uccessful (2021-10-23) || 254k || Applicative Functor; for wrong arguments it does not show a specific error message but the general usage pattern
  3 KB (401 words) - 09:41, 23 October 2021
• Mutually recursive modules
  This way it is not possible to find a sequence to compile them one after another. Up to version 6.10 it is not possible to create mutually recursive class definitions across modul
  4 KB (631 words) - 10:51, 7 August 2022
• Applications and libraries/Generic programming/Template
  <li><p>Does it support generic functions with different arities?</p></li> <li><p>Is the approach extensible, if not can we do anything about it?</p></li>
  3 KB (464 words) - 06:57, 24 December 2013
• Context alias
  ...be restructured without breaking compatibility to a certain degree. Also, it would make fine-grained class hierarchies usable. ...straintKinds extension ({{GHCUsersGuide|exts/constraint_kind||a section on it}}), you can write:
  9 KB (1,395 words) - 23:16, 24 July 2021
• List notation
  However it is [[syntactic sugar]] for <hask>(0:1:2:3:[])</hask>. :Thus it is more theoretically sound and easier to edit.
  2 KB (312 words) - 17:33, 10 January 2014
• Applications and libraries/Music and sound
  ...3. It is written in Haskell. It is designed to be simple, fast and robust. It's very stable, with one instance running for several months. ...synthesizing sound produced by musical instruments, for example, although it does capture the way certain (real or imagined) instruments permit control
  6 KB (831 words) - 20:07, 5 December 2021
• Programming performance/hay.steve Python
  ...sses with that data. I originally said it took 2 hours, but I am bringing it down to 1.5 because I was eating dinner while and watching a movie while co # iterates through a heap while destroying it (side effect)
  4 KB (416 words) - 23:25, 11 July 2021
• Newtype
  ...the type has ''exactly one constructor'' with ''exactly one field'' inside it. ...ant to make a type abstract, you can wrap it in a <hask>newtype</hask> and it'll be considered distinct to the type-checker, but identical at runtime. Yo
  6 KB (1,007 words) - 15:57, 22 May 2016
• WxHaskell
  == What is it? == ...ajor GUI platforms; including GTK, Windows, X11, and MacOS X. Furthermore, it is a mature library (in development since 1992) that supports a wide range
  9 KB (1,259 words) - 13:40, 5 May 2018
• Sox
  You can use it to write, read and play audio signals in Haskell applications.
  606 bytes (92 words) - 03:32, 26 April 2021
• GHC under Wine
  [[GHC]] runs flawlessly under Wine. Here's a guide on how to get it working. ...e haskell program to compile. Hello World examples are good. Try compiling it:<br/>
  4 KB (574 words) - 07:28, 13 October 2014
• Hac NYC/Projects
  If you need a place to host a project so that others can help with it, we suggest [http://hub.darcs.net/ darcs hub], which offers free hosting fo ...have a project that you want to work on at the Hackathon, please describe it here.
  3 KB (376 words) - 04:46, 5 April 2014
• Dynamic programming example
  ...or boxes of 20 pieces. You can only buy zero or more such boxes. Therefore it is impossible to buy exactly 5 pieces, or exactly 7 pieces, etc. Can you bu ...ught, or <hask>Just (x,y,z)</hask> if i pieces can be bought, and moreover it can be done by x boxes of 6, y boxes of 9, and z boxes of 20. Below the cod
  6 KB (929 words) - 06:42, 21 November 2020
• Diagrams/Dev/Transformations
  ...rix by such a unit vector picks out a column of the matrix, as I claimed. It's also not too hard to see that the matrix's action on any other vector is Now, if one has a matrix <math>M</math> it is easy to compute its transpose, and not too difficult to compute its inve
  14 KB (2,245 words) - 03:01, 11 April 2015
• The Monadic Way
  ...ok like and what they are useful for, from the perspective of a ... lover. It could be an introduction to "The Monadic Way" tutorial. ...cifically StateT. This part is just a skeleton, since, for the time being, it contains only the code.
  9 KB (1,615 words) - 15:16, 6 February 2021
• MapReduce as a monad
  ...general technique for massively parallel programming developed by Google. It takes its inspiration from ideas in functional programming, but has moved a ...OP framework, which is very complex and somewhat temperamental. Moreover, it is necessary to write HADOOP-specific code into mappers and reducers. My p
  6 KB (1,053 words) - 03:27, 9 April 2021
• Cabal-make
  ...kages software can do so entirely with [[Cabal]] commands. In particular, it's a bit hairy to get the best results from [[Haddock]] & [[hscolour]]. ...ine by itself, ''including'' the first one in the list (instead of placing it aside the Cabal directive). You can use "<code>make show-modules</code>" to
  5 KB (788 words) - 00:56, 12 July 2021
• Web/Existing software
  Suggests that you travel through a parallel web with translated content. It's based on Simon Marlow's Haskell Web Server.
  4 KB (491 words) - 10:14, 3 August 2015
• .lhs
  (must use "https://wiki.haskell.org/index.php?title=.lhs&redirect=no" to view it).
  703 bytes (106 words) - 20:21, 7 June 2023
• Ghc-gc-tune
  It can also generate .svg output:
  2 KB (280 words) - 15:17, 6 February 2021
• News/1990
  ...that a 3rd Haskell implementation is underway at Imperial College. Notably it compiles to native assembly.
  1 KB (203 words) - 13:27, 11 October 2021
• High-level option handling with GetOpt
  Sven Panne's GetOpt module does a fine job at parsing command line options. It required argument). It can even produce a nice usage info from option
  8 KB (1,082 words) - 23:30, 3 December 2020
• Incompatibilities between MTL 1 and MTL 2
  and mtl-2. It makes transformers more useful on its own, and also saves clients of mtl fr ''Rationale:'' This makes the instance Haskell 98, so it can be included in the
  3 KB (378 words) - 15:19, 6 February 2021
• Benchmarks Game
  ...8.8.1 is installed on the Benchmarks Game servers, please make full use of it! There is an immediate need for a complete revamp of all the entries to fix ...many of the benchmarks with no clear rational for the different versions. It'd be better to have entries for "GHC" be clean, short, functional code and
  4 KB (577 words) - 17:21, 4 February 2023
• Import
  Note that multiple import statements for the same module are also allowed, so it is possible to mix and match styles if its so desired (for example, importi ...sy to read. Typically a module only redefines a few prelude functions, and it's simpler to just hide the ones you don't want to clash with.
  4 KB (659 words) - 10:27, 14 January 2024
• Performance
  ...is along the general lines of "Can I write this program in Haskell so that it performs as well as, or better than, the same program written in some other Moreover, it's often not clear if two programs which supposedly have the same functional
  10 KB (1,392 words) - 21:39, 26 August 2018
• Web/Literature/Static linking
  ...t of date, it refers to GHC 6.8 and Database.SQLite. Please someone update it with a more recent example, if necessary.'''
  2 KB (290 words) - 03:36, 9 April 2021
• Parsing a simple imperative language
  "Principles of Program Analysis" by Nielson, Nielson and Hankin). It includes only a few statements and basic boolean/arithmetic expressions, which makes it
  11 KB (1,437 words) - 00:04, 1 September 2017
• ZuriHac2016/Projects
  I thought it might be insteresting to discuss about it with people. Being myself a recent "Haskeller" I find it quite hard
  8 KB (1,190 words) - 12:03, 24 July 2016
• Diagrams/Contributing
  ...ething or ask a question, you can be sure that someone will eventually see it and respond.) ...lan to make any modifications to the code in a certain repo, you may clone it directly instead of first forking on github and then cloning from your fork
  9 KB (1,429 words) - 02:17, 19 April 2015
• MonadFix
  ...o extension. {{GHCUsersGuide|exts/recursive_do||a section on RecursiveDo}} It is useful for building cyclic data in monadic code. == What it is not and what it is ==
  10 KB (1,757 words) - 23:34, 24 July 2021
• Pronunciation
  | just as inconvenient to convey grouping verbally, whether it's layout or punctuation
  3 KB (532 words) - 23:05, 24 July 2021
• DeepArrow
  Eros was more complicated than I like, so I started splitting it into pieces: ...ngible values'', which are separable combinations of interface and value. It uses Phooey to generate GUIs very simply from interfaces.
  3 KB (540 words) - 21:40, 3 May 2024
• Implementations
  ...ugs, it runs more slowly, and it needs more memory. However, the programs it produces run ''much'' faster. ...ing for time and space, and supports concurrent and parallel programming. It is available for most common platforms, including Windows, Mac OS X, and se
  9 KB (1,363 words) - 15:57, 9 March 2024
• Diagrams/Dev/Migrate1.3
  ...pe, potentially paving the way for things like automatic differentiation. It does, however, mean that many types are now slightly different. ...rete vector. Basically this means whenever you saw <code>v</code>, replace it by <code>v n</code>. So:
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• Functional programming/Alternative 1
  ...ations as the evaluation of expressions. This article is meant to describe it briefly, however the best way to understand functional programming is to le ...pe. If such a function '''escapes''' their block after being returned from it, the '''local variables''' must be '''retained''' in memory as they might b
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• Parsec
  Haskell. It can parse context-sensitive, infinite look-ahead grammars but it performs best on predictive (LL[1]) grammars.
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• Functional programming
  ...ations as the evaluation of expressions. This article is meant to describe it briefly; however, the best way to understand functional programming is to l ...difficult to determine statically when those resources can be released, so it is necessary to use automatic [[memory management]].
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• Eta conversion
  Extensive use of &eta;-reduction can lead to [[Pointfree]] programming. It is also typically used in certain compile-time optimisations.
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• Haskell 2010
  ...l/2009-November/021750.html announced] at November 24th 2009; GHC supports it since revision 7.0.1.
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• Cloud Haskell
  ...e purpose is to make it easier to write programs for clusters of machines. It provides a message passing communication model, inspired by and very simila ...package/distributed-process-azure distributed-process-azure] backend makes it possible to run Cloud Haskell applications on Microsoft Azure virtual machi
  12 KB (1,725 words) - 07:44, 10 August 2022
• Case comprehensions
  ...ing, suggesting the idea of ''drawn from'' as in a list comprehension. But it is very nice to reuse precisely the list comprehension syntax. but when it's used in case expressions:
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• Haddock/FAQ
  In fact it does, but you have to add spaces between parentheses and the infix symbols
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• Applicative functor
  It has turned out that many applications do not require monad functionality bu This is obviously necessary in some cases, but in other cases it is disadvantageous.
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• WxHaskell/Building
  Getting wxHaskell is easy on MacOS X and Linux. It's slightly less easy on Windows. * Linux - the wxWidgets that ships with your system (as long as it's the 2.8 one and not the 2.6 one) should work.
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• List comprehension
  ...say <tt>@undo</tt> and then your list comprehension, it will shoow you how it expands: .../docs/html/users_guide/exts/monad_comprehensions.html MonadComprehensions] it would.
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• Internationalization of Haskell programs using gettext
  ...t does the same thing for haskell files --- '''hgettext'''. You could find it on Hackage. It will gather all strings containing the function '__' from the Main.hs and w
  10 KB (1,489 words) - 15:02, 26 October 2016
• HNN
  ...ewrite. If you're interested in getting involved or just keeping an eye on it, check the [http://trac.haskell.org/HNN/ project page] and the [http://proj The instructions to get it and build it are :
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• Haskell in web browser/Calc example
  ...ent with visible border: it encloses all other elements of the calculator. It is also responsible for receiving keyboard input. ...p</hask>. All buttons use the same ''Message Box'' <code>calcmb</code>, so it is passed to each button's creation function. Each button uses its own char
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• Opting for oracles
  ...udgets_thesis_color.pdf the Fudgets thesis] refers to this implementation. It was fairly pleasant to work with and quite practical. ...- one classic example being ''concurrency''. For a language to support it, it must provide computations some means of allowing multiple sub-computations
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• The Monad.Reader/Discuss Issue11
  ...unfamiliar with FingerTrees, but very pleased with what I found. Indeed, it is easy to directly implement Incremental Maps with FingerTrees. I've atta
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• Emacs
  ...-language-server.readthedocs.io/en/latest/configuration.html#emacs setting it up with Emacs] It provides a [http://spacemacs.org/layers/+lang/haskell/README.html Haskell d
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• Reactive-banana/Examples
  ...et up an event network with your own event loop and how to pause or resume it. : A wave-like pattern. Not the most beautiful code, but it demonstrates that you can generate timed events.
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• Lifting
  ...>), you will notice that <hask>fmap</hask> already is a lifting operation: It transforms a function between simple types <hask>a</hask> and <hask>b</hask If the size of the containers isn't fixed, it's not always clear how to make lifting operations for them. The <hask>[]</h
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• Mac OS X
  ...tallers of the full Haskell Platform development environment. We recommend it: ...is an easy-to-use integrated programming environment for Haskell on OS X. It is a one-click install of a complete Haskell system, including Haskell comp
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• 99 questions/Solutions/47
  Java operator precedence (descending) as far as I could fathom it:
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• Himerge
  It technically stands for "Haskell Interface for eMerge" ; though I personally ...le ghc, you should upgrade ghc first and then run ghc-updater. Either way, it would be good to emerge ghc first, then emerge himerge.
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• Haskell a la carte
  ...). Sorts not only integers but anything that can be compared. But granted, it's not in-place. ::The ''infinite'' list of fibonacci numbers. Just don't try to print all of it.
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• Real World Applications/Event Driven Applications
  In the following, I will show a way to architecture a Haskell system so that it can scale from small "toy" applications (dealing with low level IO events) So please contribute your (clearly superior of course) alternative way to do it here: [https://www.haskell.org/haskellwiki/Real_World_Applications Real Wor
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• Gtk2Hs/Mac
  ...work with other versions of gcc that you already have installed. However, it will not work with gcc versions <= 4.2. Try running the gtk-demo program. Does it also fail?
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• Concurrency demos/Haskell-Javascript concurrency
  ==Try it out==
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• Tetris Cube
  The Tetris Cube is a three dimensional puzzle. It consists of 12 pieces. There are three colors, and there are four pieces of
  846 bytes (129 words) - 17:13, 30 August 2013
• IO then abstraction
  Even so, it is fair to object that the ‘monadified’ definition is ugly compared ...kely to disappear from the functional programming landscape any time soon, it is vital that we, as the functional programming community, somehow overcome
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• UTF-8
  ...bin/hackage-scripts/package/utf8-string utf8-string package] from Galois. It
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• Inlining and Specialisation
  The <code>INLINE</code> pragma can be applied to top-level definitions. It behaves like the <code>INLINABLE</code> pragma but makes GHC very keen to i It is a sledgehammer and without care you can make the compiler take a long ti
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• Foldable and Traversable
  When you've been using it for a little while, there seem to be some baffling omissions from the API. In other words, it is a type which supports "<hask>foldr</hask>".
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• HaRe
  ...ll 98/2010 refactoring tool for automated refactoring of Haskell programs. It is integrated with Emacs. It is being rewritten to use the GHC API.
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• 99 questions/54A to 60
  A binary tree is either empty or it is composed of a root element and two successors, which are binary trees th Since a "leaf" node is a branch with two empty subtrees, it can be useful to define a shorthand function:
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• POV-Ray SDL project
  ...fectively a scene ''construction'' language now, since a few releases back it become a Turing-complete programming language. This has heralded a new era in POV-Ray. Before it was 'just' a very powerful ray tracer. Now people routinely construct elabo
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• Diagrams/Dev/Freezing
  Some rough notes/explanations on freezing and how it relates to optimizing the backend API. Eventually these notes should go in ...ller circle. Diagrams are supposed to be scale-invariant but in actuality it would be surprising for them to be truly scale-invariant with regards to li
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• Abstract data type
  it is not necessary to completely hide the representation of data, so a normal This type is ''abstract'' because it leaves some aspects of its structure undefined, to be provided by the user
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• Monad Transformers
  ...nads-fd monads-fd]: this was the prototype of the new mtl implementation. It is now obsolete, and simply re-exports mtl version 2. But because it lacks the monad classes, you'll have to lift operations to the composite mo
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• Applications and libraries/Concurrency and parallelism
  ...supported concurrency with lightweight threads for more than a decade, and it [http://shootout.alioth.debian.org/gp4/benchmark.php?test=threadring&lang=a :hMPI is an acronym for HaskellMPI. It is a Haskell binding conforming to MPI (Message Passing Interface) standard
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• Continuation tutorials timeline
  Please update this list as it becomes outdated! If you find a tutorial, article, post, comment, or messag *:"As I understand it we can achieve a continuation passing style of programming by passing in th
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• Applications and libraries/Interfacing other languages
  ...port/haskell2010/haskell.html Haskell 2010 Language Report]. You may learn it by example at the :A tool to simplify the process of interfacing C libraries to Haskell. It is less powerful than HaskellDirect, but easier to use and more portable.
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• Real World
  An exciting, upcoming book from O'Really! Don't miss it!
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• Web/Libraries/Formlets
  ...a nothing, it won't have a default value. If you pass in a (Just "value"), it will be pre-populated with the value "value". ...irs with a value and the corresponding label, a possible default-value and it will return something of type a.
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• EclipseOn Mac OS X
  [[EclipseFP]] seems to work ok on [[Mac_OS_X]], but it doesn't seem like there is much testing on OS X. Installing per instructio
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• HaskellImplementorsWorkshop/2016/Call for Contributions
  2016 this year in Nara. It is a forum for people involved in the It is important to distinguish the Haskell Implementors' Workshop from
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• Bogre-Banana
  ...ll.org/package/bogre-banana Bogre-Banana] is a 3D game-engine for Haskell. It uses Haskell bindings to the [http://www.ogre3d.org/about OGRE 3D engine] a ...an find more information about it at [[Reactive-banana | it's wiki page]]. It is highly recommended that you read the [[FRP_explanation_using_reactive-ba
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• Monads as containers
  A [[monad]] is a container type together with a few methods defined on it. one time must be the same type (it is homogeneous).
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• Haskell in web browser
  ...ial does not focus on the specifics of DOM/CSS/XMLHTTP programming per se; it contains information how to ''use'' these interfaces in a Haskell program.
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• 99 questions/Solutions/60
  ...ight-balanced binary tree of height H. What is the maximum number of nodes it can contain? ...his question is more difficult. Try to find a recursive statement and turn it into a function <hask>minNodes</hask> that returns the minimum number of no
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• Google summer of code
  counting it as a success but I am waiting for a new release of HSE and ...0c4/687474703a2f2f692e696d6775722e636f6d2f3759586f5666742e676966 demo] of it working
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• OpenWRT
  ...the text; I originally wrote it as a blog post. Please feel free to edit it to be more third-person and wiki-appropriate.) Since my OpenWRT box has an x86_64 processor, it could almost run the
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• AutoForms
  ...orms is a library to ease the creation of Graphical User Interfaces (GUI). It does this by using generic programming to construct GUI components. ...UI. While this transformation is implemented, it is not as 'inteligent' as it could be.
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• Modest GHC Proposals
  It cannot attach to exports (i.e. if we wish to not deprecate "foo" but only i It also cannot attach to methods within classes.
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• Logic programming example
  ...ode is a full solution to a relatively simple, but classic, logic puzzle. It uses properties of the List Monad, in a straightforward way, to declarative fashion. Then it is just a matter of testing each combination to make sure it
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• Handling errors in Haskell
  There is simply no value there. This isn't a problem in the system. It means you don't care why there isn't a value, or you already know. <hask>Ma Again, depends on the code and the person writing it whether an explicit case is used. Often monads like <hask>Maybe</hask> are
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• Gtk2Hs/Tutorials/Intro
  Then we compile it... How to compile it with GHC on linux/mac/win32
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• Dependent type
  It seems to me that the dependent type construct ..., eager evaluation, and optional lazy evaluation via laziness annotations. It has a very Haskell-like syntax and is available on [http://hackage.haskell.
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• Parallelism vs. Concurrency
  ...s no semantic impact at all: the meaning of a program is unchanged whether it is executed sequentially or in parallel. Furthermore, the results are deter To this end, it can even be an advantage to do the same computation twice on different unit
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• The JavaScript Problem
  ...guage.''' JavaScript, the language, has some issues that make working with it inconvenient and make developing software harder : ...re working to achieve this, in varying forms. There are various ways to do it, but we ought to opt for compiling an existing language, Haskell, to JavaSc
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• BayHac2017/Clash
  ...its syntax and semantics from the functional programming language Haskell. It provides a familiar structural design approach to both combinational and sy * Or set it to dim lights that show the slowly diminishing state of each of the process
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• GHC/Stand-alone deriving declarations
  because the instance declaration would have a non-standard context. It would have to look like this: ...) should obviously work in a standalone deriving setting too. But perhaps it can be generalised a little. Currently you can only say
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• Programming performance
  The goal is to measure how long it takes to implement solutions to a standard problem in your programming lang ...amount of time required. If you wish, you may look at other solutions but it is preferable that you do not.
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• XHB
  ...st that it draws a window (or several windows), and ask the server to send it any input the user sends to these windows. Thus, several clients may connec ...rogram to be responsive to the user input, as well as to refresh requests, it needs to handle each event in a rather short period of time (e.g. less that
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• Module signature
  There's a package on Hackage, you want to use it, but it has some signatures and you're not sure what to do (we call this an ''indef ...has not defined a pre-instantiated package, you may be able to instantiate it yourself. First, you have to find a package which provides implementations
  10 KB (1,679 words) - 23:28, 2 April 2017
• Rhine
  Rhine is an arrowized [[FRP]] library with '''type level clocks'''. It is designed with multi-rate FRP in mind, combining synchronous arrowized FR ...ype. This clock type gives ''clock safety'' since throughout the framework it is ensured that every signal function is run at the speed of this clock.
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• Es/Librerias y Herramientas/Estructuras de Datos
  :A bundle for generic programming. It provides programming support for generic traversal as useful in the impleme :The Partial library provides a partial order class. It also provides routines for generating a Hasse diagram from a set and a part
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• BayHac2017
  <!-- Hide the "plz register" banner, it's basically too late now ...ndy Maguire: '''[http://reasonablypolymorphic.com/dont-eff-it-up Don't Eff It Up: Free Monads in Action]''' ([https://youtu.be/gUPuWHAt6SA video 46m])
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• Chaitin's construction
  ...that is lacking yet, the formulae and the concepts are not correct without it.''''' ..., a binary code for Combinatory Logic or Lambda Calculus does not suffice. It's also necessary to apply the encoded term on the binary data that follows
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• Parsing expressions and statements
  ...e a few fields. A minimalist preset is <hask>emptyDef</hask> and we change it with: ; <tt>m_identifier</tt> : parses and returns an identifier, checking that it does not clash with a reserved word.
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• Untypeable Haskell 98
  Here we document code that looks like it should be valid Haskell98, but
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• Embedded domain specific language
  ...y/039639.html Designing DSL with explicit sharing (was: I love purity, but it's killing me)] ...slated to [[LLVM]] assembly language. This warrants very fast computation. It uses shallow embedding.
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• Tutorials/Programming Haskell/Introduction
  It's about time we got some job done in [[Haskell]], eh? Now, one of my "Programming Perl". It was full of lots of practical examples of Perl
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• Avoiding IO
  ...type signature says more or less that almost everything must be expected. It is hard to test them, because they can in principle depend on every state o Thus in order to maintain modularity you should avoid I/O wherever possible. It is too tempting to unsafely disguise the use of I/O, so here instead are so
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• HaskellImplementorsWorkshop/2015/Call for Contributions
  2015 this year in Vancouver. It is a forum for people involved in the It is important to distinguish the Haskell Implementors' Workshop from
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• New monads
  It seems that the liftIO function from MonadIO can be generalized to access wh It is a new version of the mtl package with base monads: Id, and Lift, and tra
  4 KB (648 words) - 09:43, 9 December 2014
• Monad Transformers Tutorial
  ...ts 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? ...k> to an <hask>IO (Maybe a)</hask> that doesn't "fail" our Maybe monad. So it just means putting a <hask>Just</hask> in there:
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• Output/Input
  ...side effect can’t be in the functional program, it will have to be outside it. It can also be used to provide access to external resources:
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• Informatics 1 - Functional Programming
  ...textbook is Simon Thompson: Haskell, the Craft of Functional Programming. It is also recommended that students explore Miran Lipovača: Learn You a Hask ...t extra challenges and in-depth work. These sessions are quite popular, so it is expected that students have made an attempt at some of the optional exer
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• Xmonad/Using xmonad in Gnome/0.6
  ...herwise, the nautilus desktop will be raised into the floating layer where it covers all your other windows.) ...use be able to use the keyboard to e.g. getting rid of dialogues we rebind it to the left ''logo key'':
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• Do notation considered harmful
  ....haskell.org/cgi-bin/hackage-scripts/package/binary-0.4.1 Binary] package. It contains the <hask>Put</hask> monad, which in principle [http://www.haskell In fact it is a <hask>Writer</hask> monad using the <hask>Builder</hask> type, and all
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• Solution4.html
  If the compiler cannot guess which MonadPlus to use you will need to specify it when the function is called. So, <hask>parent someSheep :: Maybe Sheep</has
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• Package versioning policy
  ...rials for versioning: it allows packages to specify their own version, and it allows dependencies that specify which versions of the dependent package ar ...ime there has been an informal policy in use in the Haskell community, but it became clear that we were running into trouble with incorrectly-specified d
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• Merchandise
  *[http://www.cafepress.com/doitmonad Do it in a Monad] (monad laws on back) *[http://www.cafepress.com/monadpure "Do it in a Monad ... and remain pure!"] (various shirts with logo on front, monad
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• Manatee
  You can consider it is new environment mix Gnome and Emacs. Like Gnome to provide friendly grap ...nclude core) running in separate process to protected core won't crash. So it
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• Diagrams/Dev/Constraints
  ...the SMT solver people) gain many useful constraint-solving algorithms, so it was a good library to use. ...my proposal (or its comments, rather), and so that was what I implemented. It wasn't really any effort, since there was already a type family (V) to use.
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• Exception
  The great thing about Haskell is that it is not necessary to hard-wire the exception handling into the language. but we can handle situations where it is unacceptable for the caller to check a priori whether the call can succe
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• Base package
  ...ging from data structures to parsing combinators and debugging utilities. It is specific to the GHC implementation of Haskell. .../wikis/commentary/libraries/version-history. The below is retained because it goes back further in history.
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• Haskell Governance
  ...system. This page collects them and lists their domains of responsibility. It can be used to figure out where to direct contributions, questions, or conc
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• The Monad.Reader/Issue3/Functional Programming vs Object Oriented Programming
  ...of the pros and cons of functional or object-oriented programming. Rather, it's a guide for a new Haskell programmer coming from languages like Java, C#/ ...t and replace just the bits you want to change. This isn't as expensive as it sounds, due to the extensive data sharing that immutable objects make possi
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• DDC/FieldProjections
  ...efinition is similar to a regular <hask>instance</hask> definition in that it defines a set of functions associated with a particular type (in this case, ...f the first argument of <hask>(.)</hask> to decide what projection to use, it needs to be constrained to a data type (not just a type variable). Usually
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• CSound
  ...nd-expression}} is a framework for computer music that is based on Csound. It generates Csound code from Haskell code. The user can create music on the f
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• Time
  ...he first few data types in this guide are not widely used in practice, but it is important to understand their associated concepts before moving onto the Although <tt>AbsoluteTime</tt> is appropriate for many tasks, it is rarely used in applications and you will likely never use this data type
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• Functional dependencies
  That, however, isn't really what we want. As it stands, even a simple expression like this has an ambiguous type unless you and it will infer the type <haskell>v :: Char</haskell>
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• WxHaskell/Development/Environment
  ...release, so it pays well to ensure new code will work with both versions. It is possible to safely co-habit two versions of wxWidgets. When you do, wxHa Firstly, see [[WxHaskell/Building#Source_Release|Source Release]], however it is recommended that you do the following, instead of following the instruct
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• Curry-Howard-Lambek correspondence
  ...ore, ''given'' a value of type <hask>a</hask> (a proof of <hask>a</hask>), it ''constructs'' a value of type <hask>b</hask> (so the proof is ''transforme ...ng</hask> can be pattern matched against the constructors to see which one it proves.
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• Category theory/Natural transformation
  Let us define the <math>\eta : \Phi \to \Psi</math> natural transformation. It associates to each object of <math>\mathcal{C}</math> a morphism of <math>\ Thus, we want to build a parser combinator (we could notate it graphically with something like <math>\mathrm?\!\!\to\!\!\mathrm*</math>) w
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• Stanamic typing
  verifies the balancing constraint at compile time -- if it can. If the
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• Foldable Traversable In Prelude
  ...ntended to summarize the proposal as it now stands as of 28 January, 2015. It is a work in progress, done as best as possible, but should not be taken as ...was a large appetite in the community to "modernize" the Prelude and bring it into line with the current widespread usage of classes such as Applicative,
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• Xmonad/Guided tour of the xmonad source/StackSet.hs
  corrupting pollutants such as the IO monad and the X server, it is data structures used to store the state of xmonad. It is heavily
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• Rank-N types
  ...all</hask> can be floated out of the right-hand side of <hask>-></hask> if it appears there, so: is also a Rank-1 type because it is equivalent to the previous signature.
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• Web/Frameworks/HSP
  everything pertaining to literal XML syntax. In particular it contains injected by trhsx. It also nominally contains generic combinators for
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• WxHaskell/2.8
  ...d making sure that you have the C++ compiler option installed for MinGW as it is 'not' the default: ...path/to/wxWidgets/gcc_dll, which you will need to copy to a location where it can be found when running your executables.
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• Disposing of dismissives
  ...seems the ideal task for the implementation's garbage collector...provided it isn't carrying out a full collection each time a program e.g. uses up its q ...ogram state. Fortunately, as the technique is based on garbage collection, it can benefit from the extensive prior research, development and experience i
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• Mastermind
  It is a nice task to let the computer guess a code.
  1 KB (173 words) - 11:37, 4 January 2016
• Web/Frameworks/HAppS
  ...mentation, you may find yourself looking at blog post tutorials, but since it is rapidly changing, about half of these tutorials are out of date. ...functions. You don't need most of them, but because documentation is poor, it can be intimidating.
  4 KB (517 words) - 05:52, 8 June 2023
• Foldr Foldl Foldl'
  If you want you can copy/paste this article into your favorite editor and run it. ...s that it can't be made smaller (reduced) until the very last moment, when it's already too late.
  16 KB (2,235 words) - 10:26, 29 March 2019
• Real World Applications
  It is not always clear how to scale up from small "batch oriented" Haskell app
  978 bytes (130 words) - 14:09, 2 July 2014
• GADTs for dummies
  ...d what [[Generalised algebraic datatype]]s were or how they could be used. It almost seemed a conspiracy of silence &mdash; people who understood GADTs t Now that I have an idea of how it works, I think that it was really obvious. :) So, I want to share my understanding of GADTs. Mayb
  14 KB (2,322 words) - 13:55, 24 November 2023
• Non-empty list
  ...<hask>head</hask> says that the function applies to any list. In reality, it can only be meaningfully applied to non-empty lists. One can eliminate such It must be emphasized that we can eliminate head-of-empty-list errors
  8 KB (1,274 words) - 20:23, 18 July 2014
• Lazy vs. non-strict
  ...uction" to "evaluation"). So when the evaluation engine sees an expression it builds a [[thunk]] data structure containing whatever values are needed to ...equired by the outer expression, and converts those into eager evaluation. It can do this because the semantics (in terms of "bottom") don't change. Prog
  4 KB (643 words) - 23:33, 5 April 2021
• ZuriHac2016/BBQ
  ...ly. The weather is forecast to be a bit cloudy, but without any rain, yay! It should work out, but please don't blame us for a bit of rain, if the Swiss
  3 KB (488 words) - 13:14, 23 July 2016
• Converting numbers
  ...nge can be much larger: on the x86-64 version of Glasgow Haskell Compiler, it can store any signed 64-bit integer. ...sk> and <hask>RealFrac</hask>tional types. The name "real" indicates that it excludes <hask>Complex</hask> numbers.
  6 KB (867 words) - 01:28, 14 April 2016
• Compose Unconference 2016
  ...ve a project that you want to work on at the unconference, please describe it here.
  1 KB (198 words) - 22:03, 29 January 2016
• Xmonad/Using xmonad in XFCE
  ...atter is often touted as the most "nimble" of the lot. In my own opinion, it is simpler to use than KDE but with more configuration options (and a saner ...ake sure that xfwm4 (Xfce's default WM) is no longer started. Preferably, it'd be nice if we could have XMonad started this way as well (or even set in
  11 KB (1,742 words) - 10:28, 28 October 2013
• UnnamedStandard
  ...ypeclasses and lack of hierarchy, and the four different monoid classes in it), and most people using Haskell today use various extensions. Haskell' is t
  896 bytes (132 words) - 22:53, 19 April 2021
• Happy
  ...do the parsing. Typical usage in in the second stage of a compiler, where it will be used to generate an abstract syntax tree.
  859 bytes (138 words) - 12:00, 19 April 2021
• Compatibility Modules
  It can be difficult to write code that maintains compatibility with multiple v This module makes it into base version 4.6 but then, when releasing base 4.7, we decide that the
  7 KB (1,079 words) - 08:57, 23 May 2021
• Lub
  It provides a <hask>lub</hask> function that is consistent with the [[unamb]]
  1 KB (187 words) - 21:38, 4 February 2014
• Budapest Hackathon 2016
  ...Hackathon2014 info about the first hackathon]), and this time we will hold it in LogMeIn’s Budapest office. ...quirement really, so you can join us even if you didn't fill out the form, it just help us with the organization.
  6 KB (957 words) - 16:10, 20 August 2016
• OpenGLTutorial1
  ...permission. Parts of the tutorial have been modified and extended to keep it up to date.'' ...rite down the steps I actually can get to work in a tutorial-like fashion. It may be a good idea to read this in paralell to the tutorial linked, since P
  10 KB (1,585 words) - 09:22, 20 September 2013
• Arrow tutorial
  ...combines the output from two other arrow values using a binary operation. It works by splitting a value and operating on both halves and then combining What is <code>h</code>? How does it work?
  8 KB (1,315 words) - 00:43, 16 May 2024
• HsLua
  What is Lua? It's a scripting language (like Perl) targeted to be easily integrated into any host application. You can do it in
  13 KB (2,016 words) - 18:34, 20 August 2017
• Attribute grammar
  It is no wonder that it is exactly a compiler project homepage that provides good circular programm
  4 KB (598 words) - 07:06, 26 January 2018
• ZuriHac2013/Projects
  ...e involved and would probably work out better with more than one person on it.
  1 KB (168 words) - 22:02, 28 August 2013
• HaskellImplementorsWorkshop/2013/Call for Talks
  this year in Boston. There will be no proceedings; it is an informal It is important to distinguish the Haskell Implementors' Workshop from
  4 KB (589 words) - 14:46, 1 August 2013
• Haskell.org domain
  ...easonably well organised, while still helping people do useful things with it.
  1 KB (241 words) - 16:44, 28 May 2015
• CPlusPlus from Haskell
  Haskell (on Linux, compiled with g++). I refer to it as the "The Hard Way" because it is a tedious, hand done method of generating C++
  15 KB (2,199 words) - 00:32, 23 May 2017
• Unboxed type
  generally the type system is extended to type these unboxed values. how it underscore to indicate an unboxed type. However it does use the trailing
  3 KB (470 words) - 09:25, 12 June 2023
• ZuriHac2015/BBQ
  ...The weather is forecast to be sunny with a few clouds, yay! Nevertheless, it will get quite chilly in the evening so '''do bring some warm clothes'''; a
  3 KB (465 words) - 21:17, 27 May 2015
• WxHaskell/Download
  ...'Note:''If you have an older version of wxHaskell installed, please remove it before installing this version. Older releases can be uninstalled by clicki It is recommended to read the [[WxHaskell/Building_on_MacOS_X|notes]] on using
  5 KB (640 words) - 18:31, 31 January 2016
• Introduction to Haskell IO/Actions
  it provides as a result (for example String). We say that the action that not take any arguments. Consider '''putStrLn'''. It has the following
  14 KB (2,254 words) - 20:41, 10 November 2020
• Dealing with binary data
  ...l properties like coverage of the Unicode space and laziness, however when it comes to dealing with bytewise data, <hask>String</hask> involves a space-i Note that we are using strict bytestrings here. (It's quite common to import the
  17 KB (2,795 words) - 04:06, 16 June 2020
• HStringTemplate
  ...Java StringTemplate library] by Terrence Parr, ported by Sterling Clover. It can be used for any templating purpose, but is often used for dynamically g ...if you write the Stringable instance. The template has a single 'hole' in it called 'name', delimited by dollar signs.
  12 KB (1,726 words) - 15:16, 6 February 2021
• Applications and libraries/Generic programming/SyB
  ...cast is implemented in GHC. However other compilers do not support it and it is not going to be part of Haskell'. ...n on its own but there is no Haskell implementation that actually supports it. However, type class abstraction can be emulated using MPTC.
  5 KB (827 words) - 04:00, 6 April 2021
• Humor/Wanda
  Rolls-Royce for $2.75, it would do three million miles to the gallon, and it would deliver enough power to drive the Queen Elizabeth II. And if you
  8 KB (1,343 words) - 09:02, 13 March 2016
• Continuation
  ...gies or metaphors, that illustrate this difficult concept, or an aspect of it. ...de>goto</code> instruction... The point about <code>call/cc</code> is that it is not a ''static'' (lexical) <code>goto</code> instruction but a ''dynamic
  10 KB (1,560 words) - 12:02, 15 April 2024
• Peano numbers
  ...tural numbers using only a zero value and a successor function. In Haskell it is easy to create a type of Peano number values, but since unary representa ...and may take a long time doing so, although after you have seen only one, it is obvious that the list is not empty.
  4 KB (571 words) - 20:38, 26 November 2022
• Contstuff
  It essentially gives you access to the current continuation, which means that it lets you label certain points of execution and reuse these points later in .../hask> type can be polymorphic most of the time. You only need to specify it, if you use some of the CPS effects like <hask>abort</hask>.
  12 KB (2,067 words) - 05:43, 9 March 2021
• Bravo
  ...s necessary. If the application is supposed to be released in binary form, it's not necessary to ship the template files with the application. ...nd leads to a cleaner separation of program logic and layout. Beyond that, it helps to decrease the number of templates.
  9 KB (1,381 words) - 22:32, 29 June 2021
• Syntactic sugar/Cons
  It's not amazing that Haskell provides a lot of syntactic sugar. It's amazing that every syntactic sugar has pure functional explanations.
  16 KB (2,610 words) - 17:17, 4 February 2023
• 99 questions/Solutions/56
  It could be misunderstood that an equality checker just ignoring the branch na
  1 KB (179 words) - 13:36, 25 December 2016
• 99 questions/Solutions/14
  \y z -> y:y:z -- making it look nicer
  2 KB (220 words) - 20:45, 28 December 2014
• WebApplicationInterface
  ...e made easy to implement so the investment in supporting it is low, making it more likely to be widely used. ...defined in the interface) to the web servers and applications implementing it.
  14 KB (2,193 words) - 05:45, 12 July 2021
• Xmonad/Using xmonad on Apple OSX
  ...ig up a Haskell Platform for Leopard PPC (G4, ppc7450) if needed, although it will not be the latest version because my PPC machine died. * Full-screen mode is a good idea (to the extent that it ever is; it does not interact nicely with Exposé/Mission Control or Alt-Tab applicatio
  11 KB (1,893 words) - 17:07, 5 November 2014
• Specification and proof
  ...tica Project] has an expressive logic called P-logic, and tools supporting it
  1 KB (218 words) - 01:58, 24 March 2018
• Web/Frameworks/Inactive
  ...orks are suspected to be inactive. If you see that one is not, please move it to the [[Web/Frameworks|Frameworks]] page. Lemmachine is a REST'ful web framework that makes it easy to get HTTP right by exposing users to overridable hooks with sane def
  13 KB (1,880 words) - 07:32, 27 August 2020
• Cabal/Developer-FAQ
  ...sted extensions. Cabal will pass the appropriate flags to the compiler and it even checks that the compiler supports those extensions. # The best way to do it, if you know your users are using GHC 6.8.x is the new LANGUAGE pragma. Thi
  7 KB (998 words) - 12:32, 2 October 2020
• Xmonad/Guided tour of the xmonad source/Core.hs
  The next source file to examine is Core.hs. It defines several core data types and some of the core functionality of xmona ...nId = Int</hask>? The reason is that if <hask>type ScreenId = Int</hask>, it would be possible to accidentally do arithmetic with <hask>ScreenId</hask>s
  13 KB (2,057 words) - 10:15, 28 September 2017
• 99 questions/Solutions/48
  infixl 3 `equ'` -- was 7, changing it to 3 got me the same results as in the original question :(
  899 bytes (132 words) - 19:51, 18 January 2014
• Xmonad
  ...ame as <code>import XMonad; main = xmonad defaultConfig</code> except that it prevents you from seeing the result of xmonad upgrades.
  4 KB (590 words) - 23:41, 14 June 2017
• State Monad
  ...ample that demonstrates the use of the standard Control.Monad.State monad. It's a simple string parsing algorithm. -- this is it, the State transformation. Add 1 to the state, return -1*the state as the
  7 KB (1,055 words) - 15:06, 21 December 2018

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