This package contains the Control.Monad.Fail module providing the MonadFail class that became available in base-4.9.0.0 for older base package versions. This package turns into an empty package when used with GHC versions which already provide the Control.Monad.Fail module.

This package provides a bunch of ad hoc classes for accessing parts of a container. In practice this package is largely subsumed by the ghc-lens, but it is maintained for now as it has much simpler dependencies.

Backported versions of types that were added to transformers in transformers 0.3 and 0.4 for users who need strict transformers 0.2 or 0.3 compatibility to run on old versions of the platform.

Hslogger lets each log message have a priority and source be associated with it. The programmer can then define global handlers that route or filter messages based on the priority and source. It also has a syslog handler built in.

This Haskell package was originally present in classy-prelude.

The psqueues package provides Priority Search Queues in three different flavors:

• OrdPSQ k p v, which uses the Ord k instance to provide fast insertion, deletion and lookup. This implementation is based on Ralf Hinze's A Simple Implementation Technique for Priority Search Queues.

  Hence, it is similar to the PSQueue library, although it is considerably faster and provides a slightly different API.

• IntPSQ p v is a far more efficient implementation. It fixes the key type to Int and uses a https://en.wikipedia.org/wiki/Radix_tree, radix tree (like IntMap) with an additional min-heap property.

• HashPSQ k p v is a fairly straightforward extension of IntPSQ: it simply uses the keys' hashes as indices in the IntPSQ. If there are any hash collisions, it uses an OrdPSQ to resolve those. The performance of this implementation is comparable to that of IntPSQ, but it is more widely applicable since the keys are not restricted to Int, but rather to any Hashable datatype.

Each of the three implementations provides the same API, so they can be used interchangeably.

Typical applications of Priority Search Queues include:

• Caches, and more specifically LRU Caches;

• Schedulers;

• Pathfinding algorithms, such as Dijkstra's and A*.

This package provides a GHC.Generics-based Control.DeepSeq.Generics.genericRnf function which can be used for providing an rnf implementation.

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.

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.

This package provides Haskell bindings to the SDL2_gfx graphics library.

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

This library makes it easy to implement monads with tricky control flow. This is useful for: writing web applications in a sequential style, programming games with a uniform interface for human and AI players and easy replay capabilities, implementing fast parser monads, designing monadic DSLs, etc.

This package provides a parser and pretty printer for converting between Haskell values and JSON. JavaScript Object Notation is a lightweight data-interchange format.

A rich drop-in replacement for base. For details and documentation please visit the project's home page.

This is a Haskell module for PortMidi audio library, which supports real-time MIDI input and output.

This haskell library provides validity and validity-based testing for ghc-hspec.

SDL_mixer is a sample multi-channel audio mixer library. It supports any number of simultaneously playing channels of 16 bit stereo audio, plus a single channel of music, mixed by the popular MikMod MOD, Timidity MIDI, Ogg Vorbis, and SMPEG MP3 libraries.

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

This package provides a pure Haskell client library for the Music Player Daemon.

Protolude gives you sensible defaults for writing custom Preludes to replace the standard one provided by GHC.

This package defines orphan instances that mimic instances available in later versions of base to a wider (older) range of compilers.

The package provides mutable and immutable bit arrays.

hscolour is a small Haskell script to colourise Haskell code. It currently has six output formats: ANSI terminal codes (optionally XTerm-256colour codes), HTML 3.2 with <font> tags, HTML 4.01 with CSS, HTML 4.01 with CSS and mouseover annotations, XHTML 1.0 with inline CSS styling, LaTeX, and mIRC chat codes.

This library is intended to be a comprehensive solution to parsing and selecting quality-indexed values in HTTP headers. It is capable of parsing both media types and language parameters from the Accept and Content header families, and can be extended to match against other accept headers as well. Selecting the appropriate header value is achieved by comparing a list of server options against the quality-indexed values supplied by the client. . In the following example, the Accept header is parsed and then matched against a list of server options to serve the appropriate media using mapAcceptMedia': . > getHeader >>= maybe send406Error sendResourceWith . mapAcceptMedia > [ ("text/html", asHtml) > , ("application/json", asJson) > ] . Similarly, the Content-Type header can be used to produce a parser for request bodies based on the given content type with mapContentMedia': . > getContentType >>= maybe send415Error readRequestBodyWith . mapContentMedia > [ ("application/json", parseJson) > , ("text/plain", parseText) > ] . The API is agnostic to your choice of server.