This is only for use in developing libraries that should conform to the persistent interface, not for users of the persistent suite of database libraries.

This Haskell library provides a type class for the error function, erf, and related functions. Instances for Float and Double.

This Haskell package provides some useful control operators for looping.

Types that are parametric on a functor are like Barbies that have an outfit for each role. This package provides the basic abstractions to work with them comfortably.

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

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.

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

This package provides a Haskell module for creating 2D and 3D plots using gnuplot.

This library provides the core data types and functions for parsing Commonmark. The parser is fully Commonmark-compliant and passes the test suite. It is designed to be customizable and easily extensible. To customize the output, create an AST, or support a new output format, one need only define some new typeclass instances. It is also easy to add new syntax elements or modify existing ones.

Accurate information about source positions is available for all block and inline elements. Thus the library can be used to create an accurate syntax highlighter or an editor with live preview. The parser has been designed for robust performance even in pathological cases that tend to cause stack overflows or exponential slowdowns in other parsers, with parsing speed that varies linearly with input length.

This module locates the full directory of the running program, to allow the use of paths relative to it. FindBin supports invocation of Haskell programs via "ghci", via "runhaskell/runghc", as well as compiled as an executable.

This library provides a number of common functions and types useful in statistics. We focus on high performance, numerical robustness, and use of good algorithms. Where possible, we provide references to the statistical literature.

The library's facilities can be divided into four broad categories:

• Working with widely used discrete and continuous probability distributions. (There are dozens of exotic distributions in use; we focus on the most common.)

• Computing with sample data: quantile estimation, kernel density estimation, histograms, bootstrap methods, significance testing, and regression and autocorrelation analysis.

• Random variate generation under several different distributions.

• Common statistical tests for significant differences between samples.

This package provides a wrapper around the Pango C library that allows high-quality rendering of Unicode text. It can be used either with Cairo to output text in PDF, PS or other documents or with Gtk+ to display text on-screen.

This library implements the 'patience diff' algorithm, as well as the patience algorithm for the longest increasing subsequence problem. Patience diff computes the difference between two lists, for example the lines of two versions of a source file. It provides a good balance between performance, nice output for humans, and simplicity of implementation.

This package provides functions to fork threads and wait for their result, whether it's an exception or a normal value. Besides waiting for the termination of a single thread this package also provides functions to wait for a group of threads to terminate. This package is similar to the threadmanager, async and spawn packages. The advantages of this package are:

• Simpler API.

• More efficient in both space and time.

• No space-leak when forking a large number of threads.

• Correct handling of asynchronous exceptions.

• GHC specific functionality like forkOn and forkIOWithUnmask.

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 an abstraction for communicating with line-oriented network services while abstracting over the use of SOCKS5 and TLS (via OpenSSL)

This package provides Haskell 98 groups. A group is a monoid with invertibility.

Contravariant functors for Haskell.

This Haskell package provides an either monad transformer.

The module Data.CaseInsensitive provides the CI type constructor which can be parameterised by a string-like type like: String, ByteString, Text, etc. Comparisons of values of the resulting type will be insensitive to cases.

This library provides functions for control flow inside of monads with anaphoric variants on if and when and a C-like switch function.

Difference lists are a list-like type supporting O(1) append. This is particularly useful for efficient logging and pretty printing (e.g. with the Writer monad), where list append quickly becomes too expensive.

This package provides bifunctors for Haskell.

This package provides a compatibility layer for using GHC call stacks with different versions of the compiler.