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++.

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 pure-Haskell utilities for dealing with XML with the conduit package.

A Haskell 98 logically uninhabited data type, used to indicate that a given term should not exist.

This package provides first class functional references. In addition to the usual operations of getting, setting and composition, plus integration with the state monad, lens families provide some unique features:

• Polymorphic updating

• Traversals

• Cast projection functions to read-only lenses

• Cast toList functions to read-only traversals

• Cast semantic editor combinators to modify-only traversals

For optimal first-class support use the lens-family package with rank 2/rank N polymorphism. Lens.Family.Clone allows for first-class support of lenses and traversals for those who require Haskell 98.

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

This package provides orphan instances for Template Haskell datatypes. In particular, instances for Ord and Lift, as well as a few missing Show and Eq instances. These instances used to live in the haskell-src-meta package, and that's where the version number started.

This library provides support for parsing and generating BitTorrent files.

This package provides a drop-in replacement for the standard filepath library, operating on RawFilePath values rather than FilePath values to get the speed benefits of using ByteStrings.

This package attempts to provide support for using Amazon Web Services like S3 (storage), SQS (queuing) and others to Haskell programmers. The ultimate goal is to support all Amazon Web Services.

This package is an enhancement of the Text.Regex library. It wraps the PCRE C library providing Perl-compatible regular expressions.

This package provides fast unicode character sets for Haskell, based on complemented PATRICIA tries.

This library contains scalable timer functions provided by a timer manager.

This package provides a custom prelude with no dependencies apart from the base package.

Foundation has the following goals:

1. provide a base like sets of modules that provide a consistent set of features and bugfixes across multiple versions of GHC (unlike base).

2. provide a better and more efficient prelude than base's prelude.

3. be self-sufficient: no external dependencies apart from base;

4. provide better data-types: packed unicode string by default, arrays;

5. Numerical classes that better represent mathematical things (no more all-in-one Num);

6. I/O system with less lazy IO.

This library provides finger trees, a general sequence representation with arbitrary annotations, for use as a base for implementations of various collection types. It includes examples, as described in section 4 of Ralf Hinze and Ross Paterson, "Finger trees: a simple general-purpose data structure".

This package provides state variables, which are references in the IO monad, like IORefs or parts of the OpenGL state.

This library provides instances of Binary for the types defined in the vector package, making it easy to serialize vectors to and from disk. We use the generic interface to vectors, so all vector types are supported. Specific instances are provided for unboxed, boxed and storable vectors.

This library parses and dumps documents that are formatted according to RFC 4180, The common Format and MIME Type for Comma-Separated Values (CSV) Files. This format is used, among many other things, as a lingua franca for spreadsheets, and for certain web services.

This package provides a new data structure for accurate on-line accumulation of rank-based statistics such as quantiles and trimmed means. . See original paper: "Computing extremely accurate quantiles using t-digest" by Ted Dunning and Otmar Ertl for more details <https://github.com/tdunning/t-digest/blob/07b8f2ca2be8d0a9f04df2feadad5ddc1bb73c88/docs/t-digest-paper/histo.pdf>.

This Haskell package provides a validator that can validate an email address string against RFC 5322.

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

This package provides Haskell bindings for libcmark, the reference parser for CommonMark, a fully specified variant of Markdown. It includes bundled libcmark sources, and does not require prior installation of the C library.

This library implements unicode-casemap, the simple, non locale-sensitive unicode collation algorithm described in RFC 5051. Proper unicode collation can be done using text-icu, but that is a big dependency that depends on a large C library, and rfc5051 might be better for some purposes.

This Hackage security library provides both server and client utilities for securing the Hackage package server. It is based on The Update Framework, a set of recommendations developed by security researchers at various universities in the US as well as developers on the Tor project.