This package provides various extra monoid-related definitions and utilities, such as monoid actions, monoid coproducts, semi-direct products, "deletable" monoids, "split" monoids, and "cut" monoids.

This library provides implementations of concurrent FIFO queues (for both general boxed and primitive unboxed values) that are fast, perform well under contention, and offer a Chan-like interface. The library may be of limited usefulness outside of x86 architectures where the fetch-and-add instruction is not available.

Takes an error-throwing expression and puts it back in the Maybe it belongs in.

Note that this suffers from the https://ghc.haskell.org/trac/ghc/ticket/5902. Buyer beware.

Containers with merging via monoidal accumulation. The Monoid instances provided by the containers and unordered-containers packages merge structures in a left-biased manner instead of using the underlying monoidal structure of the value. This package wraps the types provided by these packages, but provides Monoid instances implemented in terms of the value type's mappend'.

This library provides the natural numbers for Haskell.

This library uses GHC.Generics to derive efficient optics (traversals, lenses and prisms) for algebraic data types in a type-directed way, with a focus on good type inference and error messages when possible. This package is the shared internal logic of the generic-lens and generic-optics libraries.

This Haskell package provides extras for the ghc-contravariant package.

Haskell98 invariant functors (also known as exponential functors). For more information, see Edward Kmett's article Rotten Bananas.

The functions for creating temporary files and directories in the base library are quite limited. The unixutils package contains some good ones, but they aren't portable to Windows. This library just repackages the Cabal implementations of its own temporary file and folder functions so that you can use them without linking against Cabal or depending on it being installed. This is a better maintained fork of the "temporary" package.

Highlighting-kate is a syntax highlighting library with support for nearly one hundred languages. The syntax parsers are automatically generated from Kate syntax descriptions, so any syntax supported by Kate can be added. An (optional) command-line program is provided, along with a utility for generating new parsers from Kate XML syntax descriptions.

This package is for working with the native byte-ordering of the system.

This Haskell package allows Haskell programs to access data storage systems like PostgreSQL, SQLite, and MariaDB in a type-safe way.

wizards is a package designed for the quick and painless development of interrogative programs, which revolve around a dialogue with the user, who is asked a series of questions in a sequence much like an installation wizard.

Everything from interactive system scripts, to installation wizards, to full-blown shells can be implemented with the support of wizards.

It is developed transparently on top of a free monad, which separates out the semantics of the program from any particular interface. A variety of backends exist, including console-based System.Console.Wizard.Haskeline and System.Console.Wizard.BasicIO, and the pure System.Console.Wizard.Pure. It is also possible to write your own backends, or extend existing back-ends with new features. While both built-in IO backends operate on a console, there is no reason why wizards cannot also be used for making GUI wizard interfaces.

This package provides a type called @DMap@ which generalizes @Data.Map.Map@, allowing keys to specify the type of value that can be associated with them.

This package provides semigroups for Haskell. In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative binary operation. A semigroup generalizes a monoid in that there might not exist an identity element. It also (originally) generalized a group (a monoid with all inverses) to a type where every element did not have to have an inverse, thus the name semigroup.

This library uses GHC.Generics to derive efficient optics (traversals, lenses and prisms) for algebraic data types in a type-directed way, with a focus on good type inference and error messages when possible. The library exposes a van Laarhoven interface. For an alternative interface, supporting an opaque optic type, see generic-optics.

This package provides types and combinators for linear algebra on free vector spaces.

This Haskell package provides striped pooling abstraction for managing flexibly-sized collections of resources such as database connections.

This library provides tools for ensuring that class members are shared.

This package supplements the Validity typeclass with standard properties for functions operating on them.

Clear to write, read and edit Haskell DSL for HTML.

• Names are consistent, and do not conflict with base or are keywords (all have suffix -).

• Same combinator can be used for attributes and elements (e.g. style_).

Cross platform library for file creation, modification, and deletion notification. This library builds upon existing libraries for platform specific Windows, Mac, and Linux file system event notification.

Haskell library for both generating and consuming project templates.

ost IDEs provide the concept of a project template: instead of writing all of the code for a project from scratch, you select a template, answer a few questions, and a bunch of files are automatically generated.

project-template tries to provide a canonical Haskell library for implementing the ideal templating system.

language-python is a Haskell library for lexical analysis, parsing and pretty printing Python code. It supports versions 2.x and 3.x of Python.