This package provides a canonical anonymous 1-tuple type missing from Haskell for attaching typeclass instances.

There is also the OneTuple package which by using a boxed data-type provides a 1-tuple type which has laziness properties which are more faithful to the ones of Haskell's native tuples; whereas the primary purpose of Only is to provide the traditionally so named type-wrapper for attaching typeclass instances.

Contravariant functors for Haskell.

* @Boring@ types are isomorphic to @()@. . * @Absurd@ types are isomorphic to @Void@. . See [What does () mean in Haskell -answer by Conor McBride](https://stackoverflow.com/questions/33112439/what-does-mean-in-haskell/33115522#33115522)

The conduit package is a solution to the streaming data problem, allowing for production, transformation, and consumption of streams of data in constant memory. It is an alternative to lazy I/O which guarantees deterministic resource handling, and fits in the same general solution space as enumerator/iteratee and pipes.

A decimal number has an integer mantissa and a negative exponent. The exponent can be interpreted as the number of decimal places in the value.

This Haskell package contains Template Haskell functions for generating functions similar to those in Data.List for tuples of statically known size.

This package provides a small cross-platform library for reading and modifying the system clipboard. It uses xclip or xsel at runtime.

This is a simple time library providing a simple but powerful and performant API. The backbone of the library are the Timeable and Time type classes. Each Timeable instances can be converted to a type that has a Time instances, and thus are different representations of current time.

This library provides Comonads for Haskell.

Safe Haskell introduced the notion of safe and unsafe modules. In order to make as many as possible modules ``safe'', the well-known unsafe functions were moved to distinguished modules. This makes it hard to write packages that work with both old and new versions of GHC. This package provides a single module System.Unsafe that exports the unsafe functions from the base package. It provides them in a style ready for qualification, that is, you should import them by import qualified System.Unsafe as Unsafe.

Experimental Hspec support for testing WAI applications

This package provides Haskell bindings for the OpenGL graphics system (GL, version 4.5) and its accompanying utility library (GLU, version 1.3).

This package provides an embeddable command-line interface for Lua. The interface is compatible with the standard Lua interpreter, i.e., the `lua` executable provided in a default Lua installation.

This package provides a commutative semigroup is a semigroup where the order of arguments to mappend does not matter.

This library provides a class for non-negative numbers, a wrapper which can turn any ordered numeric type into a member of that class, and a lazy number type for non-negative numbers (a generalization of Peano numbers).

This package provides the number parsers without the need to use a large (and unportable) token parser.

The doctest program checks examples in source code comments. It is modeled after doctest for Python, see the Doctest website.

This package provides a data structure representing a bidirectional mapping between two key types. Each value in the bimap is associated with exactly one value of the opposite type.

This package provides Haskell bindings for libcmark-gfm, the reference parser for GitHub Flavored Markdown, a fully specified variant of Markdown. It includes sources for libcmark-gfm and does not require prior installation of the C library.

This package provides a Haskell wrapper over the LibYAML C library.

This package provides tools to parse Haskell sources to the template-haskell abstract syntax.

SDL_mixer is a sample multi-channel audio mixer library. It supports any number of simultaneously playing channels of 16 bit stereo audio, plus a single channel of music, mixed by the popular MikMod MOD, Timidity MIDI, Ogg Vorbis, and SMPEG MP3 libraries.

This library defines an existential type Some'. . @ data Some f where \ Some :: f a -> Some f @ . in few variants, and utilities to work with it. . If you are unsure which variant to use, use the one in "Data.Some" module.

This library provides the natural numbers for Haskell.