Contravariant functors for Haskell.

Knowledge of GHC's installation directories.

This package provides distributive functors for Haskell. Dual to Traversable.

This package provides instances for QuickCheck's \"Arbitrary\" typeclass.

This Haskell package includes a thin sqlite3 wrapper based on the direct-sqlite package, as well as the entire C library, so there are no system dependencies.

RFC 4648-compliant Base64 with an eye towards performance and modernity (additional support for RFC 7049 standards)

This library provides data structures for describing changes to other data structures. In this library, a patch is something that can be applied, analogous to a function, and which distinguishes returning the argument it was provided from returning something else.

vty is a terminal GUI library in the niche of ncurses, intended to be easy to use and to provide good support for common terminal types.

This package provides the following modules: Math.NumberTheory.Logarithms and Math.NumberTheory.Powers.Integer from the arithmoi package, GHC.Integer.Logarithms.Compat and Math.NumberTheory.Power.Natural, as well as some additional functions in migrated modules.

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

This package provides a Haskell library including a Storable instance for Complex which is binary compatible with C99, C++ and Fortran complex data types.

This package provides a compatibility layer providing Binary instances for strict and lazy text types for versions older than 1.2.1 of the text package.

This package contains a wrapped name module for TimeLocale.

This package provides a Pure Haskell implementation of the SplitMix pseudorandom number generator. SplitMix is a "splittable" pseudorandom number generator that is quite fast: 9 64-bit arithmetic/logical operations per 64 bits generated. SplitMix is tested with two standard statistical test suites (DieHarder and TestU01, this implementation only using the former) and it appears to be adequate for "everyday" use, such as Monte Carlo algorithms and randomized data structures where speed is important. In particular, it should not be used for cryptographic or security applications, because generated sequences of pseudorandom values are too predictable (the mixing functions are easily inverted, and two successive outputs suffice to reconstruct the internal state).

This library provides higher order versions of Prelude classes to ease programming with polymorphic recursion and reduce UndecidableInstances.

Haskeline provides a user interface for line input in command-line programs. This library is similar in purpose to readline, but since it is written in Haskell it is (hopefully) more easily used in other Haskell programs.

Haskeline runs both on POSIX-compatible systems and on Windows.

This library provides adjunctions and representable functors for Haskell.

This package profides a class for encoding and decoding UTF8 strings with instances for several common types. It also includes several functions for working with UTF8. It aims to be lightweight, depending only on Base and including only one module.

This package converts between bytestrings and their hexadecimal string representation.

This library provides phantom types for Haskell 98, to avoid having to unsafely pass dummy arguments.

regex-applicative is a Haskell library for parsing using regular expressions. Parsers can be built using Applicative interface.

This library provides a wide array of (semi)groupoids and operations for working with them. A Semigroupoid is a Category without the requirement of identity arrows for every object in the category. A Category is any Semigroupoid for which the Yoneda lemma holds. Finally, to work with these weaker structures it is beneficial to have containers that can provide stronger guarantees about their contents, so versions of Traversable and Foldable that can be folded with just a Semigroup are added.

This package defines new symbols for a number of functions, operators and types in the base package. All symbols are documented with their actual definition and information regarding their Unicode code point. They should be completely interchangeable with their definitions. For further Unicode goodness you can enable the UnicodeSyntax language extension. This extension enables Unicode characters to be used to stand for certain ASCII character sequences, i.e. → instead of ->, ∀ instead of forall and many others.

Parsec is designed from scratch as an industrial-strength parser library. It is simple, safe, well documented (on the package homepage), has extensive libraries, good error messages, and is fast. It is defined as a monad transformer that can be stacked on arbitrary monads, and it is also parametric in the input stream type.