Lightweight pure data validation based on Applicative and Selective functors.

This package contains helper functions on top of Template Haskell.

For example, functionExtractor extracts all functions after a regexp-pattern, which can be useful if you wish to extract all functions beginning with test (for a test framework) or all functions beginning with wc (for a web service).

This library can load and store images in PNG, Bitmap, JPEG, Radiance, TIFF and GIF formats.

This package provides a simple logging abstraction that allows multiple back-ends.

This is an industrial-strength monadic parser combinator library. Megaparsec is a feature-rich package that strikes a nice balance between speed, flexibility, and quality of parse errors.

This package provides a fast, reliable priority queue implementation based on a binomial heap.

This Haskell library provides strict left folds that stream in constant memory, and you can combine folds using Applicative style to derive new folds. Derived folds still traverse the container just once and are often as efficient as hand-written folds.

This package provides Prism and Traversals for These.

Chell is a simple and intuitive library for automated testing. It natively supports assertion-based testing, and can use companion libraries such as chell-quickcheck to support more complex testing strategies.

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.

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

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

This package is an enhancement of the Text.Regex library, providing the PCRE backend to accompany regex-base, with bundled code from https://www.pcre.org.

This package provides automatic formatting for Haskell files. Both a library and an executable.

This package provides a functional library for creating efficient memo functions using tries.

This library provides tools to infer a software license from a given license file.

Experimental Hspec support for testing WAI applications

This package provides an implementation of the standard diff algorithm, and utilities for pretty printing.

This package provides a plotting library for Haskell, using gnuplot for rendering.

This library provides monad morphism utilities, most commonly used for manipulating monad transformer stacks.

Values of custom types usually have invariants imposed upon them. This package provides the Validity type class, which makes these invariants explicit by providing a function to check whether the invariants hold.

This package provides the core modules underlying diagrams, an embedded domain-specific language for compositional, declarative drawing.

This is a small library for working with changes to JSON documents. It includes a library and two command-line executables in the style of the diff and patch commands available on many systems.

LeanCheck support for test-framework. This package can be used to incorporate LeanCheck tests into test-framework test suites.