Copyright	(c) Adam Gundry 2015-2016
License	see libraries/base/LICENSE
Maintainer	ghc-devs@haskell.org
Stability	internal
Portability	non-portable (GHC extensions)
Safe Haskell	Safe
Language	Haskell2010

GHC.Records

Description

This module defines the HasField class used by the OverloadedRecordFields extension. See the <https://gitlab.haskell.org/ghc/ghc/wikis/records/overloaded-record-fields wiki page> for more details.

Synopsis

class HasField (x :: k) (r :: TYPE r_rep) (a :: TYPE a_rep) | x r -> a where
- getField :: r -> a

Documentation

class HasField (x :: k) (r :: TYPE r_rep) (a :: TYPE a_rep) | x r -> a where Source #

Constraint representing the fact that the field x belongs to the record type r and has field type a. This will be solved automatically, but manual instances may be provided as well.

Methods

getField :: r -> a Source #

Selector function to extract the field from the record.