Derive instances of Arbitrary for QuickCheck, with various options to customize implementations.

Automating the arbitrary boilerplate also ensures that when a type changes to have more or fewer constructors, then the generator either fixes itself to generate that new case (when using the uniform distribution) or causes a compilation error so you remember to fix it (when using an explicit distribution).

This package also offers a simple (optional) strategy to ensure termination for recursive types: make Test.QuickCheck.Gen's size parameter decrease at every recursive call; when it reaches zero, sample directly from a trivially terminating generator given explicitly (genericArbitraryRec and withBaseCase) or implicitly (genericArbitrary').

Long lived application data typically should not contain any thunks. This library can be used to examine values for unexpected thunks, which can then be used in assertions. This can be invaluable in avoiding memory leaks, or tracking down existing ones.

This Haskell library provides a two-dimensional zipper data structure for editing text. The structure represents the body of text and an editing cursor which can be moved through it, along with a set of editing transformations.

Text zippers are generalized over the set of data types that might be used to store lists of characters (e.g., String, T.Text, etc.). Implementations using both of these examples are provided.

Tabular provides a Haskell representation of two-dimensional data tables, the kind that you might find in a spreadsheet or or a research report. It also comes with some default rendering functions for turning those tables into ASCII art, simple text with an arbitrary delimiter, CSV, HTML or LaTeX.

Below is an example of the kind of output this library produces. The tabular package can group rows and columns, each group having one of three separators (no line, single line, double line) between its members.

    || memtest 1 | memtest 2 ||  time test  | time test 2
====++===========+===========++=============+============
A 1 ||       hog |  terrible ||        slow |      slower
A 2 ||       pig |   not bad ||        fast |     slowest
----++-----------+-----------++-------------+------------
B 1 ||      good |     awful || intolerable |    bearable
B 2 ||    better | no chance ||    crawling |     amazing
B 3 ||       meh |   well... ||  worst ever |          ok

This package includes Hakell modules providing various helper functions for Lists, Maybes, Tuples, Functions.

Text.Regex.Base provides the interface API for regex-posix, regex-pcre, regex-parsec, regex-tdfa, regex-dfa.

This package provides Haskell bindings to the X11 graphics library. The bindings are a direct translation of the C bindings.

This package provides a Haskell library including a couple of different implementations of mutable hash tables in the ST monad, as well as a typeclass abstracting their common operations, and a set of wrappers to use the hash tables in the IO monad.

This package defines a class, Hashable, for types that can be converted to a hash value. This class exists for the benefit of hashing-based data structures. The package provides instances for basic types and a way to combine hash values.

This package provides a typeclass with a single function that is designed to help convert between different types: numeric values, dates and times, and the like. The conversions perform bounds checking and return a pure Either value. This means that you need not remember which specific function performs the conversion you desire.

Haddock is a documentation-generation tool for Haskell libraries. These modules expose some functionality of it without pulling in the GHC dependency. Please note that the API is likely to change so specify upper bounds in your project if you can't release often. For interacting with Haddock itself, see the ‘haddock’ package.

Alex is a tool for generating lexical analysers in Haskell. It takes a description of tokens based on regular expressions and generates a Haskell module containing code for scanning text efficiently. It is similar to the tool lex or flex for C/C++.

This package provides tools to measure the memory usage of a Haskell value or function.

This package is a compatibility package for a singleton data type . > data Solo a = Solo a . Note: it's not a @newtype@ . @Solo@ is available in @base-4.16@ (GHC-9.2).

Cheapskate is an experimental Markdown processor in pure Haskell. It aims to process Markdown efficiently and in the most forgiving possible way. It is designed to deal with any input, including garbage, with linear performance. Output is sanitized by default for protection against cross-site scripting (XSS) attacks.

The mockery package provides support functions for automated testing.

This package enables integration of terminal screen state in html pages.

Knowledge of GHC's installation directories.

This library lets you create a one-shot timer, poll it using STM, and update it to ring at a different time than initially specified. It uses GHC event manager timeouts when available, yielding performance similar to threadDelay and registerDelay. Otherwise, it falls back to forked threads and threadDelay.

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.

The base library exposes the hGetEcho and hSetEcho functions for querying and setting echo status, but unfortunately, neither function works with MinTTY consoles on Windows. This library provides an alternative interface which works with both MinTTY and other consoles.

The doctest program checks examples in source code comments. It is modeled after doctest for Python (<https://docs.python.org/3/library/doctest.html>). . Documentation is at <https://github.com/martijnbastiaan/doctest-parallel#readme>.

This package provides a Haskell library for globbing: matching patterns against file paths.

This package provides a Haskell library for working with files and directories. It includes code for pattern matching, finding files, modifying file contents, and more.