Portability | non-portable (GHC Extensions) |
---|---|
Stability | experimental |
Maintainer | Tom Hvitved <hvitved@diku.dk> |
This module contains functionality for automatically deriving boilerplate
code using Template Haskell. Examples include instances of HDifunctor
,
ShowHD
, and EqHD
.
- derive :: [Name -> Q [Dec]] -> [Name] -> Q [Dec]
- class EqHD f where
- makeEqHD :: Name -> Q [Dec]
- class EqHD f => OrdHD f where
- makeOrdHD :: Name -> Q [Dec]
- class PShow a where
- class ShowHD f where
- makeShowHD :: Name -> Q [Dec]
- class HDifunctor f
- makeHDifunctor :: Name -> Q [Dec]
- class HFunctor h => HFoldable h
- makeHFoldable :: Name -> Q [Dec]
- class HFoldable t => HTraversable t
- makeHTraversable :: Name -> Q [Dec]
- smartConstructors :: Name -> Q [Dec]
- smartAConstructors :: Name -> Q [Dec]
- liftSum :: Name -> Q [Dec]
- caseHD :: (f a b i -> c) -> (g a b i -> c) -> (f :+: g) a b i -> c
Documentation
derive :: [Name -> Q [Dec]] -> [Name] -> Q [Dec]Source
Helper function for generating a list of instances for a list of named
signatures. For example, in order to derive instances Functor
and
ShowF
for a signature Exp
, use derive as follows (requires Template
Haskell):
$(derive [makeFunctor, makeShowF] [''Exp])
Derive boilerplate instances for parametric signatures, i.e. signatures for parametric compositional data types.
EqHD
Signature equality. An instance EqHD f
gives rise to an instance
Eq (Term f i)
. The equality test is performed inside the FreshM
monad for
generating fresh identifiers.
makeEqHD :: Name -> Q [Dec]Source
Derive an instance of EqHD
for a type constructor of any parametric
kind taking at least three arguments.
OrdHD
class EqHD f => OrdHD f whereSource
Signature ordering. An instance OrdHD f
gives rise to an instance
Ord (Term f)
.
makeOrdHD :: Name -> Q [Dec]Source
Derive an instance of OrdHD
for a type constructor of any parametric
kind taking at least three arguments.
ShowHD
Printing of parametric values.
Signature printing. An instance ShowHD f
gives rise to an instance
Show (Term f i)
.
makeShowHD :: Name -> Q [Dec]Source
Derive an instance of ShowHD
for a type constructor of any parametric
kind taking at least three arguments.
HDifunctor
class HDifunctor f Source
This class represents higher-order difunctors.
HDifunctor f => HDifunctor (:&: f p) | |
(HDifunctor f, HDifunctor g) => HDifunctor (:+: f g) |
makeHDifunctor :: Name -> Q [Dec]Source
Derive an instance of HDifunctor
for a type constructor of any parametric
kind taking at least three arguments.
HFoldable
makeHFoldable :: Name -> Q [Dec]Source
Derive an instance of HFoldable
for a type constructor of any higher-order
kind taking at least two arguments.
HTraversable
class HFoldable t => HTraversable t Source
HTraversable f => HTraversable (Cxt h f) | |
HTraversable f => HTraversable (:&: f a) | |
(HTraversable f, HTraversable g) => HTraversable (:+: f g) |
makeHTraversable :: Name -> Q [Dec]Source
Derive an instance of HTraversable
for a type constructor of any
higher-order kind taking at least two arguments.
Smart Constructors
smartConstructors :: Name -> Q [Dec]Source
Derive smart constructors for a higher-order difunctor. The smart constructors are similar to the ordinary constructors, but a 'inject . hdimap Place id' is automatically inserted.
Smart Constructors w/ Annotations
smartAConstructors :: Name -> Q [Dec]Source
Derive smart constructors with annotations for a higher-order difunctor. The smart constructors are similar to the ordinary constructors, but a 'injectA . hdimap Place id' is automatically inserted.