Known Haskell Extensions

Links

• Please see the explanation and template for writing descriptions of these extensions.
•  Cabal extension list
•  GHC extension related options
• [source:/ExtensionTables.hs Script] to generate the original tables
•  GHC survey results (including a large list of Haskell extensions)

Support Matrix

Extension Name	GHC	NHC	HUGS	JHC
ForeignFunctionInterface	True	True	True	True
RecursiveDo	True	False	True
ParallelListComp	True	False	True
PatternGuards	True	False	False
Arrows	True	False	False
ScopedTypeVariables	True	False	True
PolymorphicComponents	True	False	True
Rank2Types	True	False	True
RankNTypes	True	False	False
ExistentialQuantification	True	True	True
NewtypeDeriving	True	False	False
ImplicitParams	True	False	True
LinearImplicitParams	True	False	False
EmptyDataDecls	True	True	True	True
NoMonomorphismRestriction	True	True	False
FlexibleContexts	True	False	True
FlexibleInstances	True	False	True
TypeSynonymInstances	True	False	True	True
MultiParamTypeClasses	True	False	True
OverlappingInstances	True	False	True
IncoherentInstances	True	False	True
UndecidableInstances	True	False	False
FunctionalDependencies	True	False	True
CPP?	True	True	True
TemplateHaskell?	True	False	False
InlinePhase?	True	False	False
ContextStack?	True	False	False
Generics?	True	False	False
NoImplicitPrelude?	True	False	False
NamedFieldPuns?	False	True	False
ExtensibleRecords?	False	False	True
RestrictedTypeSynonyms?	False	False	True
HereDocuments?	False	False	True
Assertions	True	?	False
Concurrency	True	False	Coop
KindAnnotations	True	False	False
GADTs	True	False	False
InfixTypeConstructors	True	False	False
LiberalTypeSynonyms	True	False	False
RebindableSyntax?	True	False	False
RecursiveModules?	Partial	?	False	True
RewriteRules?	True	False	False
UnboxedTypes?	True	False	False
CoinductiveDictionaries?	?	False	False
PartialTypeSigs	False	False	False
Impredicativity	?	False	False
ExplicitDictionaries?	False	False	False
KindPolymorphism?	False	False	False
DataKinds?	False	False	False
MagicUnderscore	False	False	False	True
NondecreasingIndentation	Partial	?	False	?
Class Aliases	False	False	False	?

Extensions supported by two compilers

• ForeignFunctionInterface
• RecursiveDo
• ParallelListComp
• ScopedTypeVariables
• PolymorphicComponents
• Rank2Types
• ExistentialQuantification
• ImplicitParams
• EmptyDataDecls
• NoMonomorphismRestriction
• FlexibleContexts
• FlexibleInstances
• TypeSynonymInstances
• MultiParamTypeClasses
• OverlappingInstances
• IncoherentInstances
• FunctionalDependencies
• CPP