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[[Category:Libraries]] [[Category:Tools]]
The first place to look for data types or functions that do what you want is the Standard Prelude, then the [[Library Report]] (both parts of the Haskell standards documentation), then in whatever extra libraries are provided by the Haskell implementation you are using, then on the page you are looking at.
 
   
__TOC__
 
  +
The number of Haskell packages is growing rapidly. The section 'Haskell library collections' gives an ordering of all these packages by relative importance. In the section 'Haskell applications and libraries' an ordering by category is given. Finally some guidelines for developers of new packages are presented.
   
There is an effort underway to standardise many of the extra libraries that come with Haskell implementations, and at the same time extend the module namespace into a hierarchy. A document describing this project can be found [http://www.haskell.org/~simonmar/libraries/libraries.html here], and there is a [http://www.haskell.org/mailman/listinfo/libraries mailing list] for discussing issues related to libraries.
 
  +
== Haskell library collections ==
   
A large collection of [http://www.haskell.org/ghc/docs/latest/html/libraries/index.html standard hierarchical libraries] are currently distributed with GHC (from version 5.04), Hugs (from Nov 2003), and nhc98 (from 1.16).
 
  +
=== Haskell Prelude ===
  +
The most important Haskell library is called the [http://www.haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html Prelude]. It is implicitly imported by default, and includes the most commonly used functions. Make sure you know what they do and how to use them effectively.
   
[[Cabal]], The Common Architecture for Building Applications and Libraries, is an framework for packaging, building, and installing any tool developed in the Haskell language.
 
  +
=== Haskell 2010 libraries ===
  +
The Haskell 2010 [[Language and library specification]] defines a set of [http://www.haskell.org/onlinereport/haskell2010/haskellpa2.html libraries] with basic functionality which all Haskell implementations should support, including the Prelude. Changes to these libraries are handled by the [http://prime.haskell.org/ Haskell'] process.
   
This page is intended as a comprehensive list of all Haskell libraries and tools. Some of these are proof-of-concepts rather than production code. Some have no longer been maintained for a long time.
 
  +
Haskell modules that almost everybody uses are in this group, for example:
  +
[http://www.haskell.org/onlinereport/haskell2010/haskellch13.html Control.Monad], [http://www.haskell.org/onlinereport/haskell2010/haskellch20.html Data.List]
  +
and [http://www.haskell.org/onlinereport/haskell2010/haskellch41.html System.IO]. Within GHC, these are mostly grouped into the [http://hackage.haskell.org/package/base base] package, but for example [http://www.haskell.org/onlinereport/haskell2010/haskellch14.html Data.Array] is in the [http://hackage.haskell.org/package/array array] package.
   
On freshmeat.com there is [http://freshmeat.net/browse/834/?topic_id=834 an alternative list of public domain software written in Haskell]. That list is currently short (for you to change that), but in particular it displays the current development status of the software. Even more Haskell projects are documented in the [http://haskell.org/communities/ community reports] and in the archives of the [[Haskell Weekly News]].
 
  +
=== GHC bootstrap libraries ===
  +
GHC comes with an expanded version of the Haskell 2010 libraries. Together these are called the [http://www.haskell.org/ghc/docs/latest/html/libraries/index.html GHC bootstrap libraries]. You should not rely on this list being stable, since it is just the list of packages that are needed to build GHC itself (including ghci and the user guide).
   
== Program Development ==
 
  +
Examples of libraries that are GHC 7.8.3 boot libraries (but not core libraries, see below):
  +
[http://hackage.haskell.org/package/haskeline haskeline],
  +
[http://hackage.haskell.org/package/integer-gmp integer-gmp] and
  +
[http://hackage.haskell.org/package/terminfo terminfo].
   
<dl>
 
  +
=== Core Libraries ===
<dt>[http://www.cs.kent.ac.uk/projects/vital/ Vital]
 
  +
The core libraries form a subset of the packages in the Haskell Platform that has submitted to the management process described on the [[Library submissions]] page.
<dd>Vital is a visual programming environment. It is particularly intended for supporting the open-ended, incremental style of development often preferred by end users (engineers, scientists, analysts, etc.).</dd>
 
   
<dt>[http://www.cs.york.ac.uk/fp/hmake/ hmake], a Haskell-aware replacement for make</dt>
 
  +
These packages typically define basic APIs that are expected to be available in any Haskell implementation, packages that are being maintained for backwards compatibility, or in some cases, which are just needed as glue to hold the rest of the platform together.
<dd>Automatically keeps track of module dependencies (i.e. no need to write any Makefiles!). Can be used with any of the usual Haskell compilers (ghc, hbc, nhc98).</dd>
 
   
<dt>[http://www.cs.york.ac.uk/fp/cpphs/ cpphs]</dt>
 
  +
Not all GHC boot libraries are core libraries.
<dd>Cpphs is a re-implementation (in Haskell) of the C pre-processor.</dd>
 
   
<dt>[http://repetae.net/john/computer/haskell/DrIFT DrIFT]</dt>
 
  +
Examples of libraries, or packages, that belong to this group are:
<dd>DrIFT is a tool which allows derivation of instances for classes that aren't supported by the standard compilers. In addition, instances can be produced in seperate modules to that containing the type declaration. This allows instances to be derived for a type after the original module has been compiled. As a bonus, simple utility functions can also be produced from a type.</dd>
 
  +
[http://hackage.haskell.org/package/mtl Monad transformer library],
  +
[http://hackage.haskell.org/package/random random] and
  +
[http://hackage.haskell.org/package/parallel parallel].
   
<dt>[http://www.cl.cam.ac.uk/users/rje33/software.html HaskTags]</dt>
 
  +
=== Haskell Platform libraries ===
<dd>Hasktags is a simple program that generates TAGS files for Haskell code. Together with a supporting editor (e.g. NEdit, XEmacs, or Vim) TAGS files can be used to quickly find the places where functions, data constructors etc. are defined.</dd>
 
  +
On top of the Core Libraries, the [http://www.haskell.org/platform/ Haskell Platform] comes preinstalled with some additional packages that together form the [http://www.haskell.org/platform/contents.html#packages-and-documentation Haskell Platform libraries]. These libraries have been thoroughly tested before being included. The addition of these libraries with the [http://www.haskell.org/platform/ Haskell Platform] is what makes it 'batteries included'.
   
<dt>[http://www.dtek.chalmers.se/~d99josve/tagsh.tar.gz tagsh]</dt>
 
  +
Examples of included packages are:
<dd>A version of the tags program for Haskell. It uses the standardised hssource and posix library, works with GHC 5.02.1. tags file has been checked to work with vim and nedit.</dd>
 
  +
[http://hackage.haskell.org/package/attoparsec attoparsec], [http://hackage.haskell.org/package/network network] and [http://hackage.haskell.org/package/QuickCheck QuickCheck].
   
<dt>[http://home.conceptsfa.nl/~jwit/HaSpell.html HaSpell]</dt>
 
  +
=== The Hackage database ===
<dd>HaSpell is a spelling and style checker for Haskell programs. It can detect spelling errors in comments in the program text, and optionally in the code itself. There is an option to detect metasyntactic variables (such as 'foo') and 'bad function prefixes' such as 'compute' and 'doThe' - these make the program less readable and generally indicate bad programming style.</dd>
 
  +
[http://hackage.haskell.org/packages/archive/pkg-list.html Hackage] is the final layer of the Haskell library collections. [http://hackage.haskell.org/packages/archive/pkg-list.html Hackage] aims to provide a comprehensive collection of released Haskell packages, similar to Perl's CPAN or Python's PyPI.
   
<dt>[http://www.informatik.uni-bremen.de/~ewk/ewk.html Uniform Workbench]</dt>
 
  +
Start on [http://hackage.haskell.org/packages/archive/pkg-list.html Hackage] if you are looking for some functionality that did not come preinstalled with the [http://www.haskell.org/platform/ Haskell Platform].
<dd>This tool is an Integration Framework providing its services in the lazy functional programming language Haskell. The WorkBench provides support for data, control and presentation integration, so that integrated Software Development Environments can be constructed from the basis of prefabricated, off-the-shelf components. We are currently using the WorkBench to construct integrated environments for Haskell program development and for specification and proof of Z specifications.</dd>
 
   
<dt>[http://www.isi.edu/~hdaume/HAllInOne/ Haskell All-In-One]</dt>
 
  +
See also the [[Hackage|Hackage wiki page]] and [[Cabal/How to install a Cabal package | how to install a Cabal package]].
<dd>This Haskell utility takes a program implemented in multiple modules and converts it to a single module.</dd>
 
</dl>
 
   
=== Integrated Development Environments ===
 
  +
== Haskell applications and libraries ==
   
<dl>
 
  +
Applications, libraries and tools for Haskell or written in Haskell have been classified below, but you should check [http://hackage.haskell.org/packages/archive/pkg-list.html Hackage] for the latest list.
<dt>[http://www.kdevelop.org/ KDevelop]</dt>
 
<dd>This IDE supports many languages. For Haskell it [http://developer.kde.org/documentation/library/cvs-api/kdevelop/html/LangSupportStatus.html currently supports] project management, syntax highlighting, building (with GHC) & executing within the IDE.
 
</dd>
 
   
<dt>[http://leiffrenzel.de/eclipse/eclipsefp.html Haskell support for Eclipse]</dt>
 
  +
* [[/Music and sound/|Audio, music and sound]]
<dd>Eclipse is an open, extensible IDE platform for 'everything and nothing in
 
  +
* [[/Bioinformatics/]]
particular'.
 
  +
* [[/Concurrency and parallelism/]]
It is implemented in Java and runs on several platforms. The Java IDE built
 
  +
* [[/Compilers and interpreters/]]
on top of
 
  +
* [[/Compiler tools|Compiler construction, lexing, parsing, pretty printing]]
it has already become very popular among Java developers. The Haskell tools
 
  +
* [[/Cryptography|Cryptography and hashing]]
extend it to support editing (syntax coloring, code assist), compiling, and
 
  +
* [[/Data structures | Data Structures and IO Libraries]]
running
 
  +
* [[/Database interfaces/]]
Haskell programs from within the IDE. More features like source code
 
  +
* [[/Editors|Editors written in Haskell]] and [[Editors|editors for Haskell]].
navigation,
 
  +
* [[/Extended Haskell/]]
module browsing etc. will be added in the future.</dd>
 
  +
* [[/Games/]]
  +
* [[/Generic programming/]]
  +
* [[/GUI libraries|Graphical User Interface (GUI) Libraries]]
  +
* [[/Graphics/]]
  +
* [[/Hardware verification/]]
  +
* [[/Linguistics|Linguistics and natural language processing]]
  +
* [[/Mathematics/|Mathematics and physics]]
  +
* [[/Network/]]
  +
* [[/Operating system/|Operating systems and systems programming]] (also emulators)
  +
* [[/Program development/]]
  +
* [[/Robotics/]]
  +
* [[/Statistics/]]
  +
* [[/Theorem provers/]]
  +
* [[/Interfacing other languages|Tools for interfacing with other languages]]
  +
* [[Web|Web, HTML, XML]]
   
<dt>[http://www.dtek.chalmers.se/~d99josve/hide/ hIDE]</dt>
 
  +
Other places to look include:
<dd>hIDE is a GUI-based Haskell IDE written using gtk+hs. It does not include an editor but instead interfaces with NEdit, vim or GNU emacs.
 
  +
* The [[Library]] hierarchy page on this wiki.
  +
* The Haskell [[Haskell Communities and Activities Report|community reports]].
  +
* The [http://www.haskell.org/mailman/listinfo/libraries mailing list] for discussion of issues related to libraries.
   
<dt>[http://haskell.org/hide hIDE-2]</dt>
 
  +
You can also [http://www.reddit.com/r/haskell_proposals/top/?t=month propose and vote on new libraries] that you'd like on [http://www.reddit.com/r/haskell reddit], and look at our past [http://hackage.haskell.org/trac/summer-of-code/ Summer of Code proposals].
<dd>Through the dark ages many a programmer has longed for the ultimate tool. In response to this most unnerving craving, of which we ourselves have had maybe more than our fair share, the dynamic trio of #Haskellaniacs (dons, dcoutts and Lemmih) hereby announce, to the relief of the community, that a fetus has been conceived:
 
   
hIDE - the Haskell Integrated Development Environment.
 
  +
== Guidelines for developers ==
   
So far the unborn integrates source code recognition and a chameleon editor, resenting these in a snappy gtk2 environment. Although no seer has yet predicted the date of birth of our hIDEous creature, we hope that the mere knowledge of its existence will spread peace of mind throughout the community as oil on troubled waters.
 
  +
[[Image:Cabal-With-Text-small.png|frame|Built with Cabal]]
   
See also: [[Screenshots of HIDE]] and [[HIDE]]</dd>
 
  +
Developer guides:
   
<dt>[http://www.students.cs.uu.nl/people/rjchaaft/JCreator JCreator with Haskell support]</dt>
 
  +
* [[How to write a Haskell program|How to write a new Haskell library]]
  +
* [[Library submissions|How to propose changes to the standard libraries]]
  +
* [http://web.archive.org/web/20071011215053/http://pupeno.com/2006/12/12/the-lambda-revolution-v/ Creating a .deb from a Haskell Cabal package] (in the Web Archive)
  +
* Guide to making standard [[Library submissions|library submissions]]
  +
* If you notice the library documentation is lacking, or could be improved, [http://www.haskell.org/haskellwiki/Improving_library_documentation please report it here]
  +
* [http://www.google.com/codesearch Google Code Search] can help identify common idioms, improving your API.
  +
* [[Future projects]], more projects people would like.
  +
* [[Cabal]], The Common Architecture for Building Applications and Libraries, is a framework for packaging, building, and installing any tool developed in the Haskell language.
  +
* [[Hack-Nix]], a set of tools based on the [http://nixos.org Nix] package manager to manage multiple setups to build a project
   
<dd>JCreator is a highly customizable Java IDE for Windows.
 
  +
Proposals for the module name space layout that can be used to guide the construction of new libraries.
Features include extensive project support, fully customizable
 
toolbars (including the images of user tools) and menus,
 
increase/decrease indent for a selected block of text
 
(tab/shift+tab respectively). The Haskell support module adds
 
syntax highlighting for haskell files and winhugs, hugs, a static
 
checker (if you double click on the error message, JCreator will
 
jump to the right file and line and highlight it yellow) and the
 
Haskell 98 Report as tools. Platforms: Win95, Win98, WinNT and
 
Win2000 (only Win95 not tested yet). Size: 6MB.<br>
 
JCreator is a trademark of Xinox Software; Copyright &copy; 2000
 
Xinox Software<br>
 
The Haskell support module is made by [http://www.students.cs.uu.nl/people/rjchaaft/ Rijk-Jan van Haaften].</dd>
 
   
<dt>[http://www.haskell.org/visualhaskell Visual Haskell]</dt>
 
  +
* [[Hierarchical module names|Almost current guide]]
<dd>
 
  +
* [http://www.cs.york.ac.uk/fp/libraries/layout.html Proposal 1]
Visual Haskell is a complete development environment for Haskell software, based on Microsoft's [http://msdn.microsoft.com/vstudio/productinfo/ Microsoft Visual Studio] platform. Visual Haskell integrates with the Visual Studio editor to provide interactive features to aid Haskell development, and it enables the construction of projects consisting of multiple Haskell modules, using the Cabal building/packaging infrastructure.</dd>
 
  +
* [http://www.cs.york.ac.uk/fp/libraries/layoutSM.html Proposal 2]
</dl>
 
   
=== Editor Modes for syntax highlighting and more ===
 
  +
=== Libraries for other languages ===
   
<dl>
 
  +
If you are thinking about designing a new library for Haskell, you ought to look what has been done in other languages. Here are standard library definitions for
<dt>For SubEthaEdit (Mac OS X editor): <dd>[http://www.cs.kent.ac.uk/people/rpg/tatd2/Haskell.mode.zip Haskell mode].
 
<dt>For KDE's Kate</dt>
 
<dd>
 
<ul>
 
<li>[http://www.informatik.uni-bonn.de/~ralf/software.html#syntax Files] by Ralf Hinze.
 
<li>[hs.xml hs.xml] and [lhs.xml lhs.xml] by Brian Huffman.
 
</ul>
 
<dt>[http://www.nedit.org/ftp/contrib/highlighting/haskell.pats NEdit]
 
syntax highlighting and block comment support.</dt>
 
   
<dt>[http://www.vim.org vim] syntax highlighting</dt>
 
  +
* [http://wiki.clean.cs.ru.nl/Libraries Clean]
<dd>
 
  +
* [http://www.standardml.org/Basis/ Standard ML]
<ul>
 
  +
* [http://caml.inria.fr/pub/docs/manual-ocaml/manual034.html Objective Caml]
<li>[ftp://ftp.cse.unsw.edu.au/pub/users/dons/vim/ by Don Stewart]: for TeX and cpp style Haskell files.
 
  +
* [http://srfi.schemers.org/ Scheme]
<li>[http://urchin.earth.li/~ian/vim/ by Ian Lynagh]: distinguishes different literal Haskell styles.
 
<li>by John Williams: Both regular Haskell [haskell.vim .hs] and [lhaskell.vim .lhs] files
 
that uncomment lines using '&gt;' are supported.
 
</ul>
 
 
<dt>[http://www.haskell.org/libraries/Haskell98.syn Syntax highlighting file] for [http://www.textpad.com textpad]</dt>
 
 
<dd>by Jeroen van Wolffelaar and Arjan van IJzerdoorn, which
 
inludes all prelude functions, datatype, constructors, etc, all in
 
seperate groups.</dd>
 
 
<dt>[http://www.astercity.net/~khaliff/haskell/haskellmode.tgz Haskell mode]</dt>
 
 
<dd>for [http://www.jedsoft.org/jed/ jed] by
 
Marcin 'Qrczak' Kowalczyk.</dd>
 
 
<dt>[http://www.haskell.org/haskell-mode/ Haskell Mode for Emacs]</dt>
 
 
<dd>Supports font locking, declaration scanning, documentation of
 
types, indentation and interaction with Hugs.</dd>
 
 
<dt>Alternative [http://www.haskell.org/libraries/hugs-mode.el Hugs Mode for Emacs] by
 
Chris Van Humbeeck</dt>
 
 
<dd>Provides fontification and cooperation with Hugs. Updated for
 
emacs 20.* by Adam P. Jenkins.</dd>
 
</dl>
 
 
<p>Some other, mostly obsolete, modes are available in [http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/CONTRIB/haskell-modes/ CVS].</p>
 
 
=== Typesetting Haskell in TeX ===
 
 
<dl>
 
<dt>[http://www.jantar.org/lambdaTeX/ lambdaTeX]</dt>
 
 
<dd>A TeX package for typesetting literate scripts in TeX. The
 
output looks much like the code from Chris Okasaki's book "Purely
 
Functional Data Structures", doing syntax highlighting and
 
converting ASCII art such as"-&gt;" or "alpha" to proper
 
mathematical symbols. It should work with both LaTeX and plain TeX,
 
and it does its magic without any annotations, directly on the
 
source code (lambdaTeX uses an almost-complete Haskell lexical
 
analyzer written entirely in plain TeX). You only have to add
 
\input lambdaTeX at the top of your source file, and manually
 
typeset your literate comments so they look as good as the source
 
code.</dd>
 
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/haskell-style.html Haskell Style for LaTeX2e]</dt>
 
 
<dd>by Manuel Chakravarty provides environments and macros that
 
simplify setting Haskell programs in LaTeX.</dd>
 
 
<dt>[http://www.iai.uni-bonn.de/~loeh/lhs2tex/ lhs2tex]</dt>
 
 
<dd>A preprocessor for typesetting Haskell programs that combines
 
some of the good features of pphs and smugweb. It generates LaTeX code from literate Haskell sources.</dd>
 
 
<dt>[http://www.cs.uu.nl/wiki/Ehc/Shuffle Shuffle]</dt>
 
 
<dd>--- another tool helping literate programming in Haskell. It helps to maintain ''views'' in a literate programming project.
 
 
For example, it is among the tools used for developing a compiler in an iterative way with manuals didactically reflecting these evolving series of versions deriving from the literal code (see [http://www.cs.uu.nl/wiki/Ehc/WebHome Essential Haskell Compiler] project).
 
Thus, Shuffle gives us the possibility for making didactically the evolution of versions visible in the documentation, when this is needed.
 
 
More generally, Shuffle gives us tangling and weaving possibilities of literate programming.
 
I think it gives a way to think of literal program development in a more abstract way by supporting the concept of views (maybe a too far analogy: version control management -- e.g. [http://abridgegame.org/darcs/ darcs] -- helps thinking of program development in a more abstract way, too).
 
 
Shuffle works well together with lhs2tex.</dd>
 
 
<dt>[http://www.acooke.org/jara/pancito/haskell.sty haskell.sty]</dt>
 
 
<dd>A Latex style file by Andrew Cooke that makes literal
 
programming in Haskell simple.</dd>
 
</dl>
 
 
=== Source documentation and browsing ===
 
 
<dl>
 
<dt>[[Haddock]] A Haskell Documentation Tool</dt>
 
<dd>A tool for automatically generating documentation from
 
annotated Haskell source code. It is primarily intended for
 
documenting libraries, but it should be useful for any kind of
 
Haskell code. Haddock lets you write documentation annotations next
 
to the definitions of functions and types in the source code, in a
 
syntax that is easy on the eye when writing the source code (no
 
heavyweight mark-up). The documentation generated by Haddock is
 
fully hyperlinked - click on a type name in a type signature to go
 
straight to the definition, and documentation, for that type.</dd>
 
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/idoc/ IDoc] A No
 
Frills Haskell Interface Documentation System</dt>
 
 
<dd>IDoc extracts interface documentation and declarations from
 
Haskell modules based on standard Haskell layout rules and a small
 
number of clues that the programmer embeds in interface comments.
 
These clues have been designed to be visually non-imposing when
 
displaying the source in a text editor. Interface documentation is
 
rendered in standard markup languages (currently, only HTML is
 
supported). IDoc has been designed to be simple to use and
 
install.</dd>
 
 
<dt>[http://www.fmi.uni-passau.de/~groessli/hdoc/ HDoc]</dt>
 
 
<dd>HDoc generates documentation in HTML format for Haskell
 
modules. The generated documents are cross linked and include
 
summaries and detailed descriptions for the documented functions,
 
data types, type classes and instance declarations.</dd>
 
 
<dt>[http://www.ida.liu.se/~jakax/haskell.html HaskellDoc]</dt>
 
 
<dd>This program generates an HTML document showing the module
 
interfaces of a Haskell project. Convenient links are placed for
 
easy browsing of the different modules of the project, and for
 
quick access to the source code.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/explorer/browser.html The Haskell Module Browser]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dd>A browser similar to Smaltalk and Eiffel class browsers.</dd>
 
</dl>
 
 
=== Testing ===
 
 
<dl>
 
<dt>[http://hunit.sourceforge.net HUnit]</dt>
 
 
<dd>A unit testing framework for Haskell, similar to JUnit for
 
Java. With HUnit, the programmer can easily create tests, name
 
them, group them into suites, and execute them, with the framework
 
checking the results automatically. Test specification is concise,
 
flexible, and convenient.</dd>
 
 
<dt>[http://www.cs.chalmers.se/~rjmh/QuickCheck/ QuickCheck]</dt>
 
 
<dd>A tool for testing Haskell programs automatically. The
 
programmer provides a specification of the program, in the form of
 
properties which functions should satisfy, and QuickCheck then
 
tests that the properties hold in a large number of randomly
 
generated cases. Specifications are expressed in Haskell, using
 
combinators defined in the QuickCheck library. QuickCheck provides
 
combinators to define properties, observe the distribution of test
 
data, and define test data generators.</dd>
 
 
<dt>[http://www.informatik.uni-freiburg.de/~wehr/haskell/ HTF - The Haskell Test Framework]</dt>
 
 
<dd>The HTF lets you write HUnit tests and QuickCheck properties in an
 
easy and convenient way. Additionally, the HTF provides a facility for
 
testing programs by running them and comparing the actual output with
 
the expected output (so called "file-based tests").
 
 
The HTF uses Template Haskell to collect all tests and properties, so
 
you do not need to write boilerplate code for that purpose. Preprocessor
 
macros provide you with file name and line number information for tests
 
and properties that failed.</dd>
 
</dl>
 
 
=== Tracing &amp; debugging ===
 
 
Tracing gives access to otherwise invisible information about a
 
computation. Conventional debuggers allow the user to step through
 
the program computation, stop at given points and examine variable
 
contents. This tracing method is quite unsuitable for Haskell,
 
because its evaluation order is complex, function arguments are
 
usually unwieldy large unevaluated expressions and generally
 
computation details do not match the user's high-level view of
 
functions mapping values to values.
 
 
<dl>
 
<dt>[http://www.cs.mu.oz.au/~bjpop/buddha/ Buddha]</dt>
 
 
<dd>Buddha is a declarative debugger for Haskell 98 programs. It presents the evaluation of a Haskell program as a series of function applications. A typical debugging session involves a series of questions and answers. The questions are posed by the debugger, and the answers are provided by the user. The implementation of Buddha is based on program transformation.</dd>
 
 
<dt>[http://www.ida.liu.se/~henni Freja]</dt>
 
 
<dd>A compiler for a subset of Haskell. Running a compiled program
 
creates an evaluation dependency tree as trace, a structure based
 
on the idea of declarative debugging from the logic programming
 
community. A debugging session consists of the user answering a
 
sequence of yes/no questions.</dd>
 
 
<dt>[http://www.cs.york.ac.uk/fp/hat Hat]</dt>
 
 
<dd>A Haskell program is first transformed by hat-trans and then
 
compiled with nhc98 or ghc. At runtime the program writes a trace file.
 
There are tools
 
for viewing the trace in various ways: Hat-stack shows a virtual stack
 
of redexes. Hat-observe shows top-level functions in the style of
 
Hood. Hat-trail enables exploring a computation backwards,
 
starting from (part of) a faulty output or an error message.
 
Hat-detect provides algorithmic debugging in the style of
 
Freja. Hat-explore allows free navigation through a computation similar to traditional debuggers and algorithmic debugging and slicing.</dd>
 
 
<dt>[http://www.haskell.org/hood Hood]</dt>
 
 
<dd>A library that permits to observe data structures at given
 
program points. It can basically be used like print statements in
 
imperative languages, but the lazy evaluation order is not affected
 
and functions can be observed as well.</dd>
 
 
<dt>[http://www.cs.ukc.ac.uk/people/staff/cr3/toolbox/haskell/ GHood]</dt>
 
 
<dd>"Graphical Hood" - a Java-based graphical observation event
 
viewer, building on Hood.</dd>
 
</dl>
 
 
== Data structures ==
 
 
<dl>
 
<dt>[http://www.haskell.org/ghc/docs/edison/ Edison]</dt>
 
 
<dd>Chris Okasaki is developing a library of efficient data
 
structures. It provides sequences, finite maps, priority queues,
 
and sets/bags. ([http://www.eecs.usma.edu/Personnel/okasaki/pubs.html#hw00 overview paper]).</dd>
 
 
<dt>[http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/Binary.html Binary/BinArray library]</dt>
 
 
<dd>A port of Malcolm Wallace's Binary library for NHC13, offering
 
facilities for heap compression and binary I/O. A related library,
 
BinArray, uses Binary to implement imperative binary arrays.</dd>
 
 
<dt>[http://www.cs.orst.edu/~erwig/fgl/ FGL - A Functional Graph Library]</dt>
 
 
<dd>The functional graph library provides a collection of graph
 
operations.</dd>
 
 
<dt>[http://www.cs.vu.nl/Strafunski/ Strafunski]</dt>
 
 
<dd>A bundle for generic programming. It provides programming
 
support for generic traversal as useful in the implementation of
 
program transformations.</dd>
 
 
<dt>[http://www.isi.edu/~hdaume/STPP/ The Haskell STate Preprocessor]</dt>
 
 
<dd>This is a short preprocessor for stateful Haskell programs. It aleviates the pain of performing single
 
array lookup/write/update functions with some syntax to support it. It also supports hash
 
table operations based on the HashTable implementation available from the author. Finally, it supports
 
monadic if and monadic case constructions. It is lightweight in the sense that it performs no syntactic
 
analysis and is essentially a character transformer.</dd>
 
 
<dt>[http://www.cse.unsw.edu.au/~dons/fps.html Fast Packed Strings]</dt>
 
 
<dd>The FPS library provides mmapped and malloc'd packed strings (byte
 
arrays held by a ForeignPtr), along with a list interface to these
 
strings. It lets you do extremely fast IO in Haskell; in some cases,
 
even faster than typical C implementations, as well as conserving space.</dd>
 
 
</dl>
 
 
== Extended Haskell ==
 
 
The purpose of these systems is to enhance the capabilities of Haskell
 
in some way. These are not targeted at any specific application domains.
 
 
<dl>
 
<dt>[http://eecs.oregonstate.edu/~erwig/pfp/ PFP]</dt>
 
<dd>The PFP library is a collection of modules for Haskell that facilitates probabilistic functional programming, that is, programming with stochastic values. The probabilistic functional programming approach is based on a data type for representing distributions. A distribution represent the outcome of a probabilistic event as a collection of all possible values, tagged with their likelihood. A nice aspect of this system is that simulations can be specified independently from their method of execution. That is, we can either fully simulate or randomize any simulation without altering the code which defines it.</dd>
 
 
<dt>[http://www.dtek.chalmers.se/~d00nibro/harp/ HaRP]</dt>
 
<dd>A Haskell extension that extends the normal pattern matching facility with the power of regular expressions.</dd>
 
 
<dt>[http://www.haskell.org/arrows/ Arrows]</dt>
 
 
<dd>Ross Patterson has developed a preprocessor that provides a nice
 
notation for Arrows, a generalization of monads.
 
</dd>
 
 
 
<dt>[http://www.haskell.org/yampa/ Functional Reactive Programming]</dt>
 
 
<dd>Functional reactive programming integrates time flow into
 
functional programming. This provides an elegant way to express
 
computation in domains such as interactive animations, robotics,
 
computer vision, user interfaces, and simulation. The Yampa system is
 
an implementation of FRP based on arrows.
 
</dd>
 
</dl>
 
 
== Interfacing with other languages and systems ==
 
 
<dl>
 
<dt>[http://www.haskell.org/haxr/ HaXR - the Haskell XML-RPC library]</dt>
 
<dd>An XML-RPC client and server library. [http://www.xmlrpc.com/ XML-RPC] is "remote procedure calling using HTTP
 
as the transport and XML as the encoding. XML-RPC is designed to be as
 
simple as possible, while allowing complex data structures to be
 
transmitted, processed and returned."</dd>
 
 
<dt>[http://www.dcs.shef.ac.uk/~simonf/HAIFA.html HAIFA]</dt>
 
<dd>HAIFA is an implementation of parts of the web-service architecture in Haskell. Notably it includes an XML serializer, a partial implementation of XML Schema and SOAP/1.1.</dd>
 
</dl>
 
 
=== Tools for interfacing with other languages ===
 
 
The definition of a basic [http://www.cse.unsw.edu.au/~chak/haskell/ffi/ foreign function interface for Haskell (FFI)] is finished. It has been agreed on and
 
implemented by most Haskell implementors. The following tools already
 
produce code for this interface. The [http://www.reid-consulting-uk.ltd.uk/docs/ffi.html Guide to Haskell's Foreign Function Interface] provides a comparision of the different tools.
 
 
 
<dl>
 
<dt>[http://haskell.org/greencard/ Green Card]</dt>
 
 
<dd>Green Card is a foreign function interface preprocessor for
 
Haskell, simplifying the task of interfacing Haskell programs to
 
external libraries (which are normally exposed via C interfaces).
 
Green Card is currently able to generate code compatible with the
 
[../implementations.html#ghc Glasgow Haskell Compiler],
 
[../implementations.html#hugs Hugs] and [../implementations.html#nhc nhc].</dd>
 
 
<dt>[http://haskell.org/hdirect/ HaskellDirect]</dt>
 
 
<dd>HaskellDirect is an Interface Definition Language (IDL)
 
compiler for Haskell, which helps interfacing Haskell code to
 
libraries or components written in other languages (C). An IDL
 
specification specifies the type signatures and types expected by a
 
set of external functions. One important use of this language
 
neutral specification of interfaces is to specify COM (Microsoft's
 
Component Object Model) interfaces, and HaskellDirect offers
 
special support for both using COM objects from Haskell and
 
creating Haskell COM objects. HaskellDirect groks both the OSF DCE
 
dialect of IDL (including the various extensions introduced by the
 
Microsoft IDL compiler) and the OMG IIOP/CORBA dialect.</dd>
 
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/c2hs/ C-&gt;Haskell]</dt>
 
 
<dd>A lightweight tool for implementing access to C libraries from
 
Haskell.</dd>
 
 
<dt>[http://hsffig.sourceforge.net HSFFIG]</dt>
 
<dd>Haskell FFI Binding Modules Generator (HSFFIG) is a tool that takes a
 
C library include file (.h) and generates Haskell Foreign Functions
 
Interface import declarations for items (functions, structures, etc.)
 
the header defines.</dd>
 
 
<dt>[http://www.haskell.org/gcjni GCJNI]</dt>
 
 
<dd>A Java Native Interface for Haskell. Allows Haskell to invoke
 
Java code. Includes a tool to generate Haskell bindings for a Java
 
library. Works for hugs and ghc under both Linux and Windows.</dd>
 
 
<dt>[http://sourceforge.net/projects/jvm-bridge/ Haskell/Java VM Bridge]</dt>
 
 
<dd>A bridge to the Java virtual machine via JNI for Haskell.</dd>
 
 
<dt>[http://haskell.org/haskellscript/ HaskellScript]</dt>
 
 
<dd>HaskellScript is the collective name for all Haskell
 
components, both tools and libararies, that allow interaction with
 
the COM/ActiveX framework.</dd>
 
 
<dt>[http://www.astercity.net/~khaliff/haskell/kdirect/index.html KDirect]</dt>
 
 
<dd>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.</dd>
 
</dl>
 
 
=== Interfaces to specific systems ===
 
 
<dl>
 
<dt>[http://www.cse.unsw.edu.au/~dons/hs-plugins/ hs-plugins]
 
<dd>A library for compiling and loading plugins into a running Haskell program.</dd>
 
<dt>[http://www.volker-wysk.de/hsshellscript HsShellScript]</dt>
 
<dd>A library for using Haskell for tasks which are usually done by shell scripts, e.g. command line parsing, analysing paths, etc.</dd>
 
 
<dt>[http://www.cse.ogi.edu/~erik/Personal/cgi.htm CGI Library]</dt>
 
 
<dd>CGI programs can receive input from the client's web browser,
 
encoded in a complicated fashion, and can write output in a variety
 
of formats (plain text, HTML, JPEG etc) which the client then sees.
 
The decoding and encoding of the IO is often expressed in PERL or
 
C, and makes CGI applications tedious and awkward to write.
 
Haskell/CGI is a library for writing CGI programs in Haskell 1.3
 
and above.</dd>
 
 
<dt>[http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/CGI.html CGI Library]</dt>
 
 
<dd>An all-in-one-file version of Erik Meijer's CGI library (above)
 
with some bugs fixed, a few extensions and ported to Haskell
 
98.</dd>
 
 
<dt>[http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/daVinci.html daVinci binding]</dt>
 
 
<dd>A binding to daVinci, an X-Windows based visualization tool for
 
directed graphs.</dd>
 
 
<dt>[http://www-i2.informatik.rwth-aachen.de/~michaelw/hmpi.html hMPI]</dt>
 
 
<dd>hMPI is an acronym for HaskellMPI. It is a Haskell binding
 
conforming to MPI (Message Passing Interface) standard 1.1/1.2. The
 
programmer is in full control over the communication between the
 
nodes of a cluster.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/smartest.html Smarty]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dd>The world's smartest i/o device for Haskell. An interface
 
between Haskell and Squeak, a freely available Smalltalk language
 
and environment.</dd>
 
 
<dt>[http://www.haskell.org/~petersen/haskell/popenhs/ popenhs]</dt>
 
 
<dd>A small library, based on runProcess in the standardised posix library.
 
It provides lazy output from subprocesses.</dd>
 
 
<dt>[http://sourceforge.net/projects/haskell-corba/ haskell-corba]</dt>
 
 
<dd>This package allows Haskell programmers to write CORBA clients
 
and servers using the [http://www.mico.org MICO open-source CORBA implementation]. It defines a Haskell language
 
mapping for CORBA, and includes an IDL compiler which generates
 
Haskell stub and skeleton modules from IDL files.</dd>
 
</dl>
 
 
=== Interfacing with databases ===
 
 
<dl>
 
 
<dt>[http://sourceforge.net/forum/forum.php?forum_id=350240 HSQL]</dt>
 
<dd>HSQL is a simple library which provides an interface to multiple databases.
 
MySQL, PostgreSQL, ODBC, SQLite and Oracle are currently supported.
 
It is part of [http://htoolkit.sourceforge.net/ HToolkit].</dd>
 
 
<dt>[http://cvs.sf.net/viewcvs.py/haskell-libs/libs/takusen/ Takusen]</dt>
 
<dd>A library to interface to the Oracle DBMS. Part of the [http://sf.net/projects/haskell-libs Haskell-Libs project].</dd>
 
 
<dt>[http://haskelldb.sourceforge.net/ HaskellDB]</dt>
 
 
<dd>An updated version of [http://www.haskell.org/haskellDB Daan Leijen's HaskellDB] that works with current Haskell implementations and is relatively platform-independent.
 
</dd>
 
 
<dd>
 
HaskellDB is a combinator library for expressing queries and
 
other operations on relational databases in a type safe and
 
declarative way. All the queries and operations are completely
 
expressed within Haskell, no embedded (SQL) commands are needed.
 
This close integration makes it possible to do arbitrary
 
computations on the database (like computing the transitive
 
closure).</dd>
 
 
<dt>[http://members.tripod.com/~sproot/hasql.htm HaSQL]</dt>
 
 
<dd>HaSQL is a Haskell to ODBC interface. HaSQL allows Haskell
 
program to run SQL queries against an ODBC compliant database.
 
Queries with parameters are supported. Data is retrieved from the
 
database as a lazy list.</dd>
 
 
<dt>[http://www.astercity.net/~khaliff/haskell/dbi/dbi.tgz libpq binding]</dt>
 
 
<dd>A Haskell binding to libpq, a client-side PostgreSQL
 
programming library, together with a simple DBI for Haskell. It
 
enables the programmer to write database-independent code.</dd>
 
 
</dl>
 
 
== Graphical User Interface and graphics libraries ==
 
 
There exists a large number of gui and graphics libraries for
 
Haskell. Unfortunately there is no standard one and all are more or
 
less incomplete. The following list gives an overview. In
 
general, low-level veneers are going well, but they are low level.
 
High-level abstractions are pretty experimental. There is a need
 
for a supported medium-level GUI library.
 
 
{|
 
!High-level:
 
|[http://haskell.org/FranTk FranTk]
 
|[http://www.cs.chalmers.se/ComputingScience/Research/Functional/Fudgets/ Fudgets]
 
|[http://haskell.org/fruit/ Fruit] and [http://zoo.cs.yale.edu/classes/cs490/03-04b/bartholomew.robinson/ wxFruit]
 
|([http://www.dcs.gla.ac.uk/fp/software/haggis/ Haggis])
 
|-
 
!Medium-level:
 
|[http://wxhaskell.sourceforge.net wxHaskell]
 
|[http://haskell.org/gtk2hs/ Gtk2HS]
 
|[http://haskell.org/graphics/ HGL] (graphics only)
 
|[http://haskell.org/ObjectIO Object I/O]
 
|-
 
!Low-level veneers:
 
|[http://haskell.org/HOpenGL/ HOpenGL] (graphics only)
 
|[http://www.dcs.gla.ac.uk/~meurig/TclHaskell/ TclHaskell]
 
|Win32
 
|X11
 
|}
 
 
=== Graphical User Interface Libraries ===
 
 
<dl>
 
<dt>[http://wxhaskell.sourceforge.net wxHaskell]</dt>
 
<dd>[[wxHaskell]] is a portable and native GUI library built on top of wxWindows - a comprehensive C++ library that is portable across all major GUI
 
platforms; including GTK, Windows, X11, and MacOS X. wxWindows is a mature library (in development since 1992)
 
that supports a wide range of widgets with the native look-and-feel, and it has a very active community.</dd>
 
 
<dt>[http://haskell.org/gtk2hs/ Gtk2Hs]</dt>
 
<dd>Gtk2Hs is a GUI library for Haskell based on [http://www.gtk.org Gtk+].
 
Gtk+ is an extensive and mature multi-platform toolkit for creating graphical
 
user interfaces. Gtk2Hs is actively developed, supporting the latest version
 
of the Gtk+ 2.x series. It provides automatic memory management, Unicode
 
support and also bindings for various Gnome modules.
 
It runs on Windows, Linux, MacOS X, FreeBSD and Solaris.</dt>
 
 
<dt>[http://htoolkit.sourceforge.net/ HToolkit]</dt>
 
<dd>HToolkit is a portable Haskell library for writing graphical user
 
interfaces (GUI's). The library is built upon a low-level interface that will
 
be implemented for each different target platform. The low-level library is called Port and is currently implemented for GTK and Windows. The middle-level
 
library is named GIO (the Graphical IO library) and is built upon the low-level Port library.</dd>
 
 
<dt>[http://www.informatik.uni-bremen.de/htk HTk]</dt>
 
<dd>Htk is a typed, portable encapsulation of Tcl/Tk into Haskell.
 
Its distinctive features are the use of Haskell types and type
 
classes for structuring the interface, an abstract notion of event
 
for describing user interaction, and portability across Windows,
 
Unix and Linux.</dd>
 
 
<dt>[http://www.dcs.gla.ac.uk/~meurig/TclHaskell/ TclHaskell]</dt>
 
<dd>TclHaskell is a library of functions for writing platform
 
independent, graphical user interfaces in Haskell. The library
 
provides a convenient, abstract and high-level way to write
 
window-oriented applications. It also provides a more low level
 
interface to write primitive Tcl code where helpful.<br>
 
For Unix and Windows (and Macintosh?).</dd>
 
 
<dt>[http://www.cs.chalmers.se/ComputingScience/Research/Functional/Fudgets/ Fudgets]</dt>
 
<dd>Fudgets is primarily a Graphical User Interface Toolkit for the
 
functional programming language Haskell and the X Windows system.
 
Fudgets also makes it easy to create client/server applications
 
that communicate via the Internet.
 
 
<ul>
 
<li>[http://www.cs.chalmers.se/ComputingScience/Research/Functional/Fudgets/springschool95-intro.html Programming with Fudgets]: A short presentation of the Fudget Library and
 
the ideas underlying it.</li>
 
</ul>
 
 
For Unix, not Windows.</dd>
 
 
<dt>[http://www.haskell.org/fruit/ Fruit]</dt>
 
<dd>Another high-level approach to GUI's in Haskell. It is based on the concepts of Functional Reactive Programming and arrows.
 
 
There is also another implementation of this approach, called [http://zoo.cs.yale.edu/classes/cs490/03-04b/bartholomew.robinson/ wxFruit]. It is implemented on top of wxHaskell.</dd>
 
 
<dt>[http://haskell.org/FranTk FranTk]</dt>
 
<dd>is a library for building GUIs in Haskell. FranTk uses
 
behaviours and events, concepts from Conal Elliot's Functional
 
Reactive Animation. FranTk provides good support for developing
 
complex dynamic systems, and is built on top of Tcl-Tk. This makes
 
it platform independent. FranTk was developed by [http://www.dcs.gla.ac.uk/~meurig Meurig Sage].<br>
 
For Unix and Windows.</dd>
 
 
<dt>[http://haskell.org/ObjectIO Object I/O for Haskell]</dt>
 
<dd>A port of Clean Object I/O library for Haskell</dd>
 
</dl>
 
 
==== Unsupported GUI-libraries ====
 
 
The following libraries seem to be no longer maintained. However,
 
someone might pick up one of them or at least profit from some
 
design ideas.
 
 
<dl>
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/gtk/ Gtk+HS] a Haskell binding for GTK+</dt>
 
 
<dd>This library provides a transcription of the original GTK+ API
 
into Haskell. GTK+ is a modern, portable GUI library and forms the
 
basis of the Gnome desktop project. The binding, while not
 
complete, covers most of GTK+'s core functionality and is ready for
 
use in applications that require a GUI of medium complexity.<br>
 
Developed under Unix, but should also be usable with the Windows port of GTK+.</dd>
 
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/gtk/#iHaskell iHaskell]</dt>
 
<dd>A functional wrapper on top of GTK+HS that provides convenience functions
 
for frequently used programming patterns and eliminates the need for explicit
 
mutable variables.</dd>
 
 
<dt>[http://www.dcs.gla.ac.uk/fp/software/haggis/ Haggis]</dt>
 
 
<dd>Haggis is a graphical user interface framework for the
 
functional language Haskell, running under the X Window system. It
 
is being developed using the Glasgow Haskell Compiler with its
 
concurrent extensions to achieve more comfortable interaction with
 
the outside world.</dd>
 
 
<dt>Haskell-Tk</dt>
 
<dd>is a concurrent, strongly typed and higher order encapsulation
 
of Tk that supports the definition of user dialogues. Einar
 
Karlsson developed it for his [http://www.informatik.uni-bremen.de/~ewk/WB.html UniForm WorkBench].</dd>
 
 
<dt>Pidgets</dt>
 
<dd>developed by [http://www.informatik.uni-trier.de/~ley/db/indices/a-tree/s/Scholz:Enno.html Enno Scholz] unifies pictures and widgets in a constraint-based framework for
 
concurrent functional GUI programming.</dd>
 
 
<dt>[http://www.reid-consulting-uk.ltd.uk/alastair/publications/gfpw93/ Budgets]</dt>
 
<dd>A library of Fudget-like combinators based on the Openlook widget library
 
was developed by [http://www.reid-consulting-uk.ltd.uk/alastair/ Alastair Reid] and Satnam Singh.
 
The code has suffered tremendous bit-rot (does anyone have a copy
 
of ghc-0.16?) but all the reusable ideas are described in the [http://www.reid-consulting-uk.ltd.uk/alastair/publications/gfpw93/ paper].</dd>
 
 
<dt>[http://drcjt.freeyellow.com/EW.html Embracing Windows]</dt>
 
<dd>is a framework for developing graphical user interfaces. It
 
runs under Windows 95 using a modified version of Hugs 1.3.</dd>
 
 
<dt>Gadgets</dt>
 
<dd>Lazy functional components for graphical user interfaces,
 
developed by Rob Noble under the supervision of [http://www.cs.york.ac.uk/~colin/ Colin Runciman] (LNCS 982, pages 321-340).</dd>
 
</dl>
 
 
=== Graphics ===
 
 
<dl>
 
<dt>[http://haskell.org/graphics/ The Hugs Graphics Library]</dt>
 
<dd>The Hugs Graphics Library supports 2-dimensional graphics
 
operations, timers, mouse and keyboard actions and multiple
 
windows. It runs on Hugs under both Win32 and X11. An earlier
 
version was used for early prototypes of Fran.</dd>
 
 
<dt>[http://haskell.org/haven/ Haven]</dt>
 
<dd>Scalable Vector Graphics for Haskell. Portable,
 
device-independent, resolution-independent library, including
 
support for affine transformations, Bezier curves, fine-grained
 
control of pen attributes, bounds and intersection tests,
 
constructive area geometry, anti-aliased rendering, outline fonts,
 
etc.</dd>
 
 
<dt>[http://afavant.elte.hu/~wferi/funcmp/ Functional Metapost]</dt>
 
<dd>Functional Metapost is a Haskell binding for MetaPost, the powerful but
 
cumbersome graphics language.</dd>
 
 
<dt>[http://www.conal.net/Fran/ Functional Reactive Animation]</dt>
 
<dd>FRAN is a Haskell library (or "embedded language") for
 
interactive animations with 2D and 3D graphics and sound. It runs
 
on Hugs under Windows 95 and Windows NT, using Win32 graphics
 
(GDI).</dd>
 
 
<dt>[http://www.conal.net/pan Pan]</dt>
 
<dd>An embedded language and highly optimizing compiler for image
 
synthesis and transformation, based on the simple idea of images as
 
functions over infinite, continuous 2D space. The resulting
 
binaries can be used as PhotoShop plugins, embedded in web pages or
 
PowerPoint, or used in an interactive standalone viewer. The
 
compiler contains no domain-specific knowledge, so it's very
 
extensible. See the [http://www.conal.net/pan/gallery gallery] for
 
visual examples. Currently Windows-only, but ports are
 
encouraged.</dd>
 
 
<dt>[http://haskell.org/edsl/pansharp.html Pan#]</dt>
 
<dd>Pan# is a slightly re-engineered version of Pan. It uses the same
 
compiler but used the Microsoft .NET framework instead of visual
 
studio, making it easier to install and use. It also has a number of
 
new features added. While Pan is embedded in Haskell, Pan# has its own
 
Haskell-like language built in so there is no need to use other Haskell
 
compilers.
 
Currently Windows-only.
 
</dd>
 
 
<dt>[http://www.acooke.org/jara/pancito/index.html Pancito]</dt>
 
<dd>Pancito is a Haskell module for manipulating functional images
 
and then saving them to disk. It was inspired by Pan.</dd>
 
 
<dt>[http://haskell.org/HOpenGL/ HOpenGL]</dt>
 
<dd>HOpenGL is a Haskell binding for the OpenGL graphics API (GL
 
1.2.1 / GLU 1.3) and the portable OpenGL utility toolkit GLUT.</dd>
 
</dl>
 
 
=== Graphics File Formats ===
 
 
<dl>
 
<dt>[http://web.archive.org/web/20010628003610/http://www.numeric-quest.com/haskell/Gif/ Gif Writer]<em>(since 10/06/2003: via Internet Archive; this library is no longer available!)</em></dt>
 
<dd>A simple tool - capable of producing GIF based plots from
 
within Haskell programs. Such plots can be then incorporated into
 
HTML reports, to literate Haskell programs, or to combination of
 
both.</dd>
 
 
<dt>[http://www.cs.uu.nl/people/jeroen/ Functional Specification of the JPEG algorithm, and an Implementation for Free]</dt>
 
 
<dt>[http://www.students.cs.uu.nl/people/dgruijs/jpg/jpg.html JPEG encoding]
 
Written in Gofer.</dt>
 
</dl>
 
 
== Web, HTML, XML ==
 
 
<dl>
 
<dt>[http://www.haskell.org/http/ HTTP and Browser Modules]</dt>
 
 
<dd>A significantly RFC compliant HTTP/1.1 implementation. This is an updated version of [http://homepages.paradise.net.nz/warrickg/haskell/http/ Warrick Gray's original version].</dd>
 
 
<dt>[http://www.informatik.uni-freiburg.de/~thiemann/haskell/WASH/ WASH]</dt>
 
 
<dd>A family of combinator libraries for programming Web
 
applications. WASH/HTML is for generating dynamic HTML documents,
 
combining flexibility and safety. WASH/CGI is for server-side Web
 
scripting with sessions, compositional forms, and graphics.</dd>
 
 
<dt>[http://www.cs.york.ac.uk/fp/HaXml/ HaXml: utilities for using XML with Haskell]</dt>
 
 
<dd>Includes an XML parser, an HTML parser, a pretty-printer, a
 
combinator library for generic XML transformations, and two
 
Haskell&gt;-&lt;XML converters using type-based translation.</dd>
 
 
<dt>[http://www.cse.ogi.edu/~andy/html/intro.htm The Haskell Html Library] by Andy Gill</dt>
 
 
<dd>This library is a collection of combinators, allowing your
 
Haskell programs to generate HTML.</dd>
 
 
<dt>[http://www.fh-wedel.de/~si/HXmlToolbox/ Haskell XML Toolbox]</dt>
 
 
<dd>The Haskell XML Toolbox bases on the ideas of HaXml and HXML, but
 
introduces a more general approach for processing XML with Haskell. The
 
Haskell XML Toolbox uses a generic data model for representing XML
 
documents, including the DTD subset and the document subset, in
 
Haskell.</dd>
 
 
<dt>[http://www.cse.ogi.edu/~erik/Personal/cgi.htm CGI Library]</dt>
 
 
<dd>CGI programs can receive input from the client's web browser,
 
encoded in a complicated fashion, and can write output in a variety
 
of formats (plain text, HTML, JPEG etc) which the client then sees.
 
The decoding and encoding of the IO is often expressed in PERL or
 
C, and makes CGI applications tedious and awkward to write.
 
Haskell/CGI is a library for writing CGI programs in Haskell 1.3
 
and above.</dd>
 
 
<dt>[http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/CGI.html CGI Library]</dt>
 
 
<dd>An all-in-one-file version of Erik Meijer's CGI library (above)
 
with some bugs fixed, a few extensions and ported to Haskell
 
98.</dd>
 
 
<dt>[http://home.tiscali.be/stevevh/ Generative Implementation Strategies for Data-Centric Web Applications]
 
<dd>Generic presentation layer abstractions of administrative web applications
 
are the central theme of this thesis. The domain-engineering approach
 
results in a framework to support user interfaces generated from high-level
 
descriptions. A domain-specific language describes user interfaces. The
 
[hoyweghenSoft.zip Haskell-based generator] transforms these descriptions to user interfaces
 
implemented with JavaScript and XHTML.</dd>
 
 
<dt>[http://www.cs.chalmers.se/~d00nibro/hsp Haskell Server Pages]</dt>
 
<dd>Using Haskell as a server-side scripting language, extended to allow embedded XML/XHTML fragments in Haskell code.</dd>
 
 
</dl>
 
 
 
== Pretty-printer libraries ==
 
 
<dl>
 
<dt>[http://research.microsoft.com/~simonpj/downloads/pretty-printer/pretty.html Pretty printer library]</dt>
 
 
<dd>Simon Peyton Jones made an "industrial strength" pretty
 
printing library in Haskell, based on John Hughes's paper "The
 
Design of a Pretty-printing Library" (in Advanced Functional
 
Programming, Johan Jeuring and Erik Meijer (eds), LNCS 925). <a
 
href="http://www.md.chalmers.se/~rjmh/Software/NewPP.hs">Original
 
version by John Hughes</a>.</dd>
 
 
<dt>[http://www.cs.uu.nl/groups/ST/Software/PP/ Pretty-printing combinators]</dt>
 
 
<dd>The combinators in the library are optimal in the sense that
 
they produce the layout with the smallest height possible. They
 
also allow the programmer to specify several different
 
layouts.</dd>
 
 
<dt>[http://www.cs.uu.nl/~daan/pprint.html PPrint]</dt>
 
 
<dd>PPrint is an implementation of the pretty printing combinators described by Philip Wadler.
 
The PPrint library adds new primitives to describe commonly occuring layouts and works well in
 
practice.</dd>
 
</dl>
 
 
== Compiler and compilation tools ==
 
 
<dl>
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/ctk/ Manuel Chakravarty's Compiler Toolkit]</dt>
 
 
<dd>There is a significant set of functionality that is required in
 
each compiler like symbol table management, input-output
 
operations, error management, and so on, which are good candidates
 
for code reuse. The Compiler Toolkit is an attempt to provide an
 
open collection of modules for these recurring tasks in
 
Haskell.</dd>
 
 
<dt>[http://www.cs.princeton.edu/zephyr/ASDL/ The Zephyr Abstract Syntax Description Lanuguage (ASDL)]</dt>
 
 
<dd>ASDL is a language designed to describe the tree-like data
 
structures in compilers. Its main goal is to provide a method for
 
compiler components written in different languages to interoperate.
 
ASDL makes it easier for applications written in a variety of
 
programming languages to communicate complex recursive data
 
structures. asdlGen is a tool that takes ASDL descriptions and
 
produces implementations of those descriptions in C, C++, Java,
 
Standard ML, and Haskell.</dd>
 
 
<dt>[http://www.cse.ogi.edu/~mpj/thih/ Typing Haskell in Haskell]</dt>
 
 
<dd>A Haskell program that implements a Haskell typechecker, thus
 
providing a mathematically rigorous specification in a notation
 
that is familiar to Haskell users.</dd>
 
 
<dt>[http://www.cs.mu.oz.au/~bjpop/hatchet.html Hatchet]</dt>
 
 
<dd>Hatchet is a type checking and inference tool for Haskell 98,
 
written in (almost) Haskell 98.</dd>
 
 
<dt>[http://www.cs.chalmers.se/~aarne/BNF/ The BNF Converter]</dt>
 
 
<dd>A High-Level Tool for Implementing Well-Behaved Programming
 
Languages.</dd>
 
 
<dt>[http://www.cwi.nl/projects/MetaEnv/haterm/ ATerm Library]</dt>
 
 
<dd>ATerms provide a generic format for representation and exchange
 
of (annotated) terms. ATerms were developed in the context of the
 
ASF+SDF Meta-Environment. They are also used by the rewriting
 
language Stratego, by the transformation tool bundle XT, by the
 
visitor generator JJForester, and by numerous other tools developed
 
at CWI, Universiteit Utrecht, and elsewhere.</dd>
 
 
<dt>Attribute Grammar</dt>
 
 
<dd>How can attribute grammars help at the separation of concerns, at things related to the goals of aspect oriented programming? How do they relate to other concepts like monads and arrows?
 
Why are they important for the functional programmer? See Wouter Swierstra's [http://www.haskell.org/tmrwiki/WhyAttributeGrammarsMatter WhyAttributeGrammarsMatter].
 
 
Utrecht University's [http://www.cs.uu.nl/wiki/HUT/AttributeGrammarSystem Attribute Grammar System] tools include also an attribute grammar compiler, UUAGC. The concept of attribute grammar was used in their [http://www.cs.uu.nl/wiki/Ehc/WebHome Essential Haskell Compiler] project, which gives us not only a working programming language, but also a good didactical material about using attribute grammars, e.g. in writing compilers.</dd>
 
 
</dl>
 
 
=== Scanner and parser generators ===
 
 
<dl>
 
 
<dt>[http://www.haskell.org/happy/ Happy]</dt>
 
 
<dd>[[Happy]] is a parser generator system for Haskell, similar to the
 
tool `yacc' for C. Like `yacc', it takes a file containing an
 
annotated BNF specification of a grammar and produces a Haskell
 
module containing a parser for the grammar.</dd>
 
 
<dt>[http://www.ki.informatik.uni-frankfurt.de/~klose/lucky.html Lucky]</dt>
 
 
<dd>A parser generator for Haskell using monadic parser
 
combinators. It was developed to be compatible with Happy.</dd>
 
 
<dt>[http://www.cs.uu.nl/wiki/Center/UtrechtParserCombinators Utrecht Parser Combinator Library]</dt>
 
 
<dd>The combinators in this library analyse the grammar on the fly and build parsers that are quite efficient. An interesting aspect is that parsing results become available on the fly without hanging on to the input. The parsers will give extensive error reports of erroneous situations, and wil proceed with parsing. </dd>
 
 
<dt>[http://www.cs.ruu.nl/~daan/parsec.html Parsec]</dt>
 
 
<dd>A simple, well documented monadic parser combinator library for
 
fast parsers with good error messages.</dd>
 
 
<dt>[http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/hsparser.html HParser]</dt>
 
 
<dd>A parser for Haskell written purely in Haskell (using the Happy
 
parser generator).</dd>
 
 
<dt>[http://www.cse.unsw.edu.au/~chak/haskell/ctk/ CTKlight]</dt>
 
 
<dd>Standalone distribution of the self-optimising lexer and parser
 
combinators of the Compiler Toolkit (CTK).</dd>
 
 
<dt>[http://www.haskell.org/alex/ Alex: A Lexical Analyser Generator]</dt>
 
 
<dd>[[Alex]] 2.0 is a Lex-like package for generating Haskell
 
scanners.</dd>
 
 
<dt>[http://www.nondot.org/sabre/Projects/HaskellLexer/ The Haskell Dynamic Lexer Engine]</dt>
 
 
<dd>This system is completely dynamic: the lexer may be modified at
 
runtime, and string buffers may be lexed by different lexers at
 
different times.</dd>
 
</dl>
 
 
== Music ==
 
 
<dl>
 
<dt>[[Haskore|The Haskore Computer Music System]]</dt>
 
 
<dd>Haskore is a collection of Haskell modules designed for
 
expressing musical structures in the high-level, declarative style
 
of functional programming. Haskore is a means for describing music
 
- in particular Western Music - rather than sound. It is not a
 
vehicle for synthesizing sound produced by musical instruments, for
 
example, although it does capture the way certain (real or
 
imagined) instruments permit control of dynamics and articulation.
 
Haskore compositions can be translated into various executable
 
formats like MIDI and printed in traditional notation.</dd>
 
 
<dt>[http://meltin.net/hacks/haskell/ HasChorus]</dt>
 
 
<dd>A set of Haskell modules written on top of Haskore to make it
 
easier to sequence simple, repetitive music.</dd>
 
</dl>
 
 
== Numerical algorithms and mathematics ==
 
 
<dl>
 
<dt>[http://www.dinkla.net/fp/cglib.html The Library for Geometric Algorithms]</dt>
 
 
<dd>is a small Haskell library, that contains algorithms for
 
two-dimensional convex hulls, triangulations of polygons,
 
Voronoi-diagrams and Delaunay-triangulations, the QEDS data
 
structure, kd-trees and range-trees.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/fractions.html Numerics with fractions]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/Roots.html Roots of polynomials]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dd>It implements the well known Laguerre's method for finding
 
complex roots of polynomials.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/Orthogonals.html Indexless linear algebra algorithms]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dd>Orthogonalization, solution of linear equations, eigenvalues
 
and eigenvectors.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/ State vector evolution]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/ Short study of fuzzy oscillator]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dt>[http://haskelldsp.sourceforge.net/ Libraries for digital signal processing]</dt>
 
<dd>Modules for matrix manpulation, digital signal processing, spectral
 
stimation, and frequency estimation.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/Tensor.html N-dimensional tensors]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dt>[http://www.info.unicaen.fr/~karczma/arpap/ Papers by Jerzy Karczmarczuk]</dt>
 
 
<dd>Some interesting uses of Haskell in mathematics, including
 
functional differentiation.</dd>
 
 
<dt>[http://haskell.org/docon/ DoCon]</dt>
 
 
<dd>Algebraic Domain Constructor</dd>
 
 
<dt>[http://www.robtougher.com/ HaskellMath]</dt>
 
 
<dd>
 
The HaskellMath library is a sandbox for me to experiment with mathematics algorithms. So far I've implemented a few quantitative finance models (Black Scholes and Binomial Trees) and basic linear algebra functions. Next I'll probably work on linear programming (simplex and interior point methods), and then I may return to more quantitative finance. All comments welcome!
 
</dd>
 
 
 
</dl>
 
 
== Hardware verification ==
 
 
<dl>
 
<dt>[http://www.cse.ogi.edu/PacSoft/projects/Hawk/ Hawk, Specifying and Prototyping Microprocessors]</dt>
 
 
<dd>The goal of the Hawk project is to develop a language for
 
expressing highly abstracted specifications of modern
 
microprocessor designs, to provide design teams with the ability to
 
dynamically explore a wide range of design choices. The Hawk
 
language is Haskell plus the Hawk library.</dd>
 
 
<dt>[http://www.cs.chalmers.se/~koen/Lava/ Lava]</dt>
 
 
<dd>Lava is a hardware description language based upon
 
Haskell.</dd>
 
</dl>
 
 
== Robots ==
 
 
<dl>
 
<dt>[http://haskell.org/yampa/ Haskell for Vision and Robotics]</dt>
 
 
<dd>Frob is an Embedded Domain Specific Language for controlling
 
robots. It is built using the principals of Functional Reactive
 
Programming, as developed by Conal Elliott for the Fran animation
 
system. The current incarnation of Frob is part of the Yampa FRP system.<br>
 
</dl>
 
 
== Cognitive Science ==
 
 
(Tools, algorithms, frameworks, paradigms concerning Genetic Programming, Artificial Intelligence, Neural Networks, Fuzzy Logic, Natural Language Processing etc.)
 
 
<dt>Genetic programming</dt>
 
 
<dd>Dr. Tina Yu's [http://www.cs.mun.ca/~tinayu/index_files/Page426.htm publications], many of them on fruitful applications of Functional Programming in Genetic Programming.
 
 
Deryck F. Brown, A. Beatriz Garmendia-Doval and John A. W. McCall, [http://www.comp.rgu.ac.uk/staff/jm/myPublications.html A Genetic Algorithm Framework Using Haskell]</dd>
 
 
<dt>Natural language processing</dt>
 
 
<dd>Articles and/or projects on linguistic theories concerning Haskell, combinatory logic, e.g.
 
* A Haskell application for natural language parsing, based on ''Applicative Universal Grammar'' (AUG) is described in Mark P. Jones', Paul Hudak's and Sebastian Shaumyan's [http://citeseer.ist.psu.edu/jones95using.html Using Types to Parse Natural Language]. The Haskell source code given by the article is full, it can be run by Gofer, and after a few modification, by GHC too (''transpose'' must be explictly imported from module ''List'', and class ''Text'' renamed to ''Show'').
 
* A more detailed description of the topic of this previous article described in Sebastian Shaumyan and Paul Hudak's [http://citeseer.ist.psu.edu/510871.html Linguistic, Philosophical, and Pragmatic Aspects of Type-Directed Natural Language Parsing]
 
* Bernard Paul Sypniewski's [http://elvis.rowan.edu/~bps/ling/introAUG.pdf An Introduction to Applicative Universal Grammar] (this link seems now broken, I hope only temporarily). As an article describing what AUG is, see also Shaumyan's [http://citeseer.ist.psu.edu/shaumyan98two.html Two Paradigms of Linguistics: The Semiotic versus Non-Semiotic Paradigm].
 
* On natural languages relating to combinatory logic, see also Peter Steedman's [http://citeseer.ist.psu.edu/steedman97does.html Does Grammar Make Use of Bound Variables?]
 
* Mark Hepple: [http://citeseer.ist.psu.edu/hepple90grammar.html The Grammar and Processing of Order and Dependency: a Categorial Approach]
 
</dd>.
 
 
== Various ==
 
 
<dl>
 
<dt>[http://www2-data.informatik.unibw-muenchen.de/EdComb/ EdComb]
 
<dd>Editor combinators allow to assemble structure editors compositionally instead of generating them from descriptions, just
 
as parsing combinators allow to assemble parsers compositionally instead of employing parser generators to generate
 
parsers from grammar descriptions.
 
<dt>[http://ls5-www.cs.uni-dortmund.de/~peter/Expander2/Expander2.html Expander2]</dt>
 
<dd>Expander2 is a flexible multi-purpose workbench for rewriting, verification,
 
constraint solving, flow graph analysis and related procedures that
 
build up proofs or computation sequences. Moreover, tailor-made
 
interpreters display terms as 2D structures ranging from trees and
 
rooted graphs to tables, fractals and
 
other turtle-system-generated pictures.</dd>
 
 
<dt>[http://www.cs.vu.nl/Strafunski/ Strafunski]</dt>
 
 
<dd>Strafunski is a Haskell bundle that provides support for
 
generic programming in Haskell, based on the concept of a
 
functional strategy. It consists of a combinator library
 
(StrategyLib) and a precompiler (DrIFT-Strafunski).</dd>
 
 
<dt>[http://www.cin.ufpe.br/~haskell/fungen FunGEn - a game engine for Haskell]</dt>
 
 
<dd>FunGEn (Functional Game Engine) is a 2D platform-independent
 
game engine implemented in and for Haskell, using HOpenGL. It is
 
intended to help game programmers in the game development process,
 
in a faster and automated way.</dd>
 
 
<dt>[http://www.haskell.org/crypto The Haskell Cryptographic Library]</dt>
 
 
<dd>A library of cryptographic functions collected together in one package.</dd>
 
 
<dt>[http://www.cif.rochester.edu/~sankeld/RSA/ RSA]</dt>
 
 
<dd>A number theory library, RSA library, and RSA programs.</dd>
 
 
<dt>[http://web.comlab.ox.ac.uk/oucl/work/ian.lynagh/ Implementations of MD5, SHA1 and DES]</dt>
 
 
<dt>[http://www.dcs.gla.ac.uk/~meurig/regexp/ Regular expression library]</dt>
 
 
<dd>Inspired by the Perl regular expression library, written purely
 
in Haskell. Also part of the GHC distribution.</dd>
 
 
<dt>[http://www.cl.cam.ac.uk/users/kw217/libs/ Partial v0.1]</dt>
 
 
<dd>The Partial library provides a partial order class. It also
 
provides routines for generating a Hasse diagram from a set and a
 
partial order. Renderers are provided for the abstract Hasse
 
diagram representation into LaTeX (via Xy-pic) and into dot, the
 
format for AT&amp;T's Graphviz tools. Since no horizontal sorting
 
is done, the Xy-pic output is rather poor at present; dot does a
 
much better job with its layout optimisation algorithm.</dd>
 
 
<dt>[http://web.archive.org/web/*/http://www.numeric-quest.com/funpdf/ fun-&gt;pdf]<em>(since 10/06/2003: via Internet Archive)</em></dt>
 
 
<dd>An implementation of a PDF dynamic writer in Haskell.</dd>
 
 
<dt>[http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/GetOpt.html GetOpt]</dt>
 
 
<dd>A module for GNU-/POSIX-like option handling of commandline
 
arguments</dd>
 
</dl>
 
 
== Collections of libraries ==
 
 
* [http://www.cs.york.ac.uk/fp/software.html Software available from the York FP group]
 
* [http://repetae.net/john/computer/haskell/ John Meacham's Haskell tools and libraries]
 
* [http://www.cit.gu.edu.au/~arock/haskell/index.html Andrew Rock's library of useful modules]
 
* [http://www.informatik.uni-bonn.de/~ralf/software.html Libraries by Ralf Hinze] for data structures, sorting, searching, parsing, pretty printing, numerical algorithms, monads, etc.
 
* [http://web.archive.org/web/*/http://www.numeric-quest.com/haskell/index.html Collection of Haskell modules] ''(since 10/06/2003: via Internet Archive)'' by Jan Skibinski, Numeric Quest Inc.
 
* [http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/haskell_libs/ Sven's Haskell Libaries] for interfacing to DaVinci, HTML/Cgi, OpenGL; a module for option handling, a Haskell parser, a binary library.
 
* [http://web.comlab.ox.ac.uk/oucl/work/ian.lynagh/ Ian Lynagh's Haskell libraries]
 
* [http://www.reid-consulting-uk.ltd.uk/projects/index.html Reid Consulting's Libraries and Programs] CMI, TSL, Knit, Greencard, HGL, HSX11, HSWin32
 
 
== Libraries for other languages ==
 
If you are thinking about designing a new library for Haskell, you
 
ought to look what has been done in other languages. Here are
 
standard library definitions for
 
 
<ul>
 
<li>[http://srfi.schemers.org/ Scheme]</li>
 
 
<li>[http://cm.bell-labs.com/cm/cs/what/smlnj/doc/basis/index.html ML]</li>
 
</ul>
 

Latest revision as of 19:47, 4 April 2019


The number of Haskell packages is growing rapidly. The section 'Haskell library collections' gives an ordering of all these packages by relative importance. In the section 'Haskell applications and libraries' an ordering by category is given. Finally some guidelines for developers of new packages are presented.

Haskell library collections

Haskell Prelude

The most important Haskell library is called the Prelude. It is implicitly imported by default, and includes the most commonly used functions. Make sure you know what they do and how to use them effectively.

Haskell 2010 libraries

The Haskell 2010 Language and library specification defines a set of libraries with basic functionality which all Haskell implementations should support, including the Prelude. Changes to these libraries are handled by the Haskell' process.

Haskell modules that almost everybody uses are in this group, for example: Control.Monad, Data.List and System.IO. Within GHC, these are mostly grouped into the base package, but for example Data.Array is in the array package.

GHC bootstrap libraries

GHC comes with an expanded version of the Haskell 2010 libraries. Together these are called the GHC bootstrap libraries. You should not rely on this list being stable, since it is just the list of packages that are needed to build GHC itself (including ghci and the user guide).

Examples of libraries that are GHC 7.8.3 boot libraries (but not core libraries, see below): haskeline, integer-gmp and terminfo.

Core Libraries

The core libraries form a subset of the packages in the Haskell Platform that has submitted to the management process described on the Library submissions page.

These packages typically define basic APIs that are expected to be available in any Haskell implementation, packages that are being maintained for backwards compatibility, or in some cases, which are just needed as glue to hold the rest of the platform together.

Not all GHC boot libraries are core libraries.

Examples of libraries, or packages, that belong to this group are: Monad transformer library, random and parallel.

Haskell Platform libraries

On top of the Core Libraries, the Haskell Platform comes preinstalled with some additional packages that together form the Haskell Platform libraries. These libraries have been thoroughly tested before being included. The addition of these libraries with the Haskell Platform is what makes it 'batteries included'.

Examples of included packages are: attoparsec, network and QuickCheck.

The Hackage database

Hackage is the final layer of the Haskell library collections. Hackage aims to provide a comprehensive collection of released Haskell packages, similar to Perl's CPAN or Python's PyPI.

Start on Hackage if you are looking for some functionality that did not come preinstalled with the Haskell Platform.

See also the Hackage wiki page and how to install a Cabal package.

Haskell applications and libraries

Applications, libraries and tools for Haskell or written in Haskell have been classified below, but you should check Hackage for the latest list.

Other places to look include:

You can also propose and vote on new libraries that you'd like on reddit, and look at our past Summer of Code proposals.

Guidelines for developers

Built with Cabal

Developer guides:

Proposals for the module name space layout that can be used to guide the construction of new libraries.

Libraries for other languages

If you are thinking about designing a new library for Haskell, you ought to look what has been done in other languages. Here are standard library definitions for