Guide to GHC Extensions

A guide to the wide variety of Haskell extensions available in GHC, aimed at people who know most of the Standard Haskell core.

The extensions which are currently covered are:

The following extensions will probably never be covered (usually because they were deprecated and/or removed from GHC sufficiently long ago):

Most of the information these tutorials present is derived from the relevant chapter of the GHC User’s Guide, as well as selected parts of the GHC source code.

How to Enable Extensions 24 Jan 2016Alexander Altman

An introduction to how to enable extensions in GHC
Language Standards 26 Jan 2016Alexander Altman

`Haskell98` and `Haskell2010`
Basic Syntax Extensions 26 Jan 2016Alexander Altman

`PostfixOperators`, `TupleSections`, `PackageImports`, `OverloadedStrings`, `UnicodeSyntax`, `RecursiveDo`, `DoRec`, `LambdaCase`, `EmptyCase`, `MultiWayIf`, `BinaryLiterals`, `NegativeLiterals`, `NumDecimals`, `DoAndIfThenElse`, and `NondecreasingIndentation`
Pattern and Guard Extensions 22 Jan 2016Alexander Altman

`NPlusKPatterns`, `BangPatterns`, `ViewPatterns`, `PatternGuards`, `PatternSignatures`, and `PatternSynonyms`
Explicit `forall` 22 Jan 2016Alexander Altman

`ExplicitForAll`, `ScopedTypeVariables`, `LiberalTypeSynonyms`, `RankNTypes `, `Rank2Types`, and `PolymorphicComponents`
List and Comprehension Extensions 22 Jan 2016Alexander Altman

`ParallelListComp`, `TransformListComp`, `MonadComprehensions`, and `OverloadedLists`
Data Type Extensions 22 Jan 2016Alexander Altman

`DatatypeContexts`, `EmptyDataDecls`, `ExistentialQuantification`, `GADTSyntax`, and `GADTs`