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Language extensions

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(List of language extensions by name)
(List of language extensions by name)
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* [[Datatype contexts|DatatypeContexts]] : Add type constraints to your datatype.
 
* [[Datatype contexts|DatatypeContexts]] : Add type constraints to your datatype.
 
* [[Default signatures|DefaultSignatures]]
 
* [[Default signatures|DefaultSignatures]]
* [[Generics|DeriveGeneric]]
+
* Derive:
  +
** [http://www.haskell.org/ghc/docs/latest/html/users_guide/deriving.html#deriving-typeable DeriveDataTypeable]
  +
** [http://www.haskell.org/ghc/docs/latest/html/users_guide/deriving.html#deriving-typeable DeriveGeneric]
  +
** [http://www.haskell.org/ghc/docs/latest/html/users_guide/deriving.html#deriving-typeable DeriveFunctor]
  +
** [http://www.haskell.org/ghc/docs/latest/html/users_guide/deriving.html#deriving-typeable DeriveFoldable]
  +
** [http://www.haskell.org/ghc/docs/latest/html/users_guide/deriving.html#deriving-typeable DeriveTraversable]
 
* [[Existential type|ExistentialQuantification]]
 
* [[Existential type|ExistentialQuantification]]
 
* [[Flexible contexts|FlexibleContexts]]
 
* [[Flexible contexts|FlexibleContexts]]

Revision as of 18:16, 18 December 2012

Language extensions are used to enable language features in Haskell that may seem useful in certain cases. They can be used to loosen restrictions in the type system or add completely new language constructs to Haskell.

They can be enabled using the LANGUAGE pragma or (in GHC) using the flag -X. The LANGUAGE pragma should be preferred here.

Before just using the language extension that fits your need, think about when it is useful and what risk it may bring to your program.

List of language extensions by name

This list is far from complete and needs extension.