Copyright | (c) 2010-2011 Patrick Bahr |
---|---|

License | BSD3 |

Maintainer | Patrick Bahr <paba@diku.dk> |

Stability | experimental |

Portability | non-portable (GHC Extensions) |

Safe Haskell | None |

Language | Haskell98 |

This module contains functionality for automatically deriving boilerplate
code using Template Haskell. Examples include instances of `HFunctor`

,
`HFoldable`

, and `HTraversable`

.

## Synopsis

- derive :: [Name -> Q [Dec]] -> [Name] -> Q [Dec]
- class ShowHF f where
- class KShow a where
- makeShowHF :: Name -> Q [Dec]
- class EqHF f where
- class KEq f where
- makeEqHF :: Name -> Q [Dec]
- class EqHF f => OrdHF f where
- makeOrdHF :: Name -> Q [Dec]
- class HFunctor h
- makeHFunctor :: 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]
- liftSum :: Name -> Q [Dec]
- makeGeneric :: [Name] -> [Type] -> Q [Dec]
- makeInstancesLike :: [Name] -> [Type] -> Q [Dec] -> Q [Dec]
- data GenericExample

# 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 higher-order signatures, i.e. signatures for generalised compositional data types.

## HShowF

Signature printing. An instance `ShowHF f`

gives rise to an instance
`KShow (HTerm f)`

.

Nothing

makeShowHF :: Name -> Q [Dec] Source #

Derive an instance of `ShowHF`

for a type constructor of any higher-order
kind taking at least two arguments.

## EqHF

Signature equality. An instance `EqHF f`

gives rise to an instance
`KEq (HTerm f)`

.

makeEqHF :: Name -> Q [Dec] Source #

Derive an instance of `EqHF`

for a type constructor of any higher-order
kind taking at least two arguments.

## OrdHF

class EqHF f => OrdHF f where Source #

Signature ordering. An instance `OrdHF f`

gives rise to an instance
`Ord (Term f)`

.

makeOrdHF :: Name -> Q [Dec] Source #

Derive an instance of `OrdHF`

for a type constructor of any parametric
kind taking at least three arguments.

## HFunctor

This class represents higher-order functors (Johann, Ghani, POPL '08) which are endofunctors on the category of endofunctors.

makeHFunctor :: Name -> Q [Dec] Source #

Derive an instance of `HFunctor`

for a type constructor of any higher-order
kind taking at least two arguments.

## HFoldable

class HFunctor h => HFoldable h Source #

#### Instances

(All HFoldable fs, All HFunctor fs) => HFoldable (Sum fs) Source # | |

Defined in Data.Comp.Multi.Ops hfold :: Monoid m => Sum fs (K m) :=> m Source # hfoldMap :: forall m (a :: Type -> Type). Monoid m => (a :=> m) -> Sum fs a :=> m Source # hfoldr :: forall (a :: Type -> Type) b. (a :=> (b -> b)) -> b -> Sum fs a :=> b Source # hfoldl :: forall b (a :: Type -> Type). (b -> a :=> b) -> b -> Sum fs a :=> b Source # | |

HFoldable f => HFoldable (Cxt h f) Source # | |

Defined in Data.Comp.Multi.Term hfold :: Monoid m => Cxt h f (K m) :=> m Source # hfoldMap :: forall m (a :: Type -> Type). Monoid m => (a :=> m) -> Cxt h f a :=> m Source # hfoldr :: forall (a :: Type -> Type) b. (a :=> (b -> b)) -> b -> Cxt h f a :=> b Source # hfoldl :: forall b (a :: Type -> Type). (b -> a :=> b) -> b -> Cxt h f a :=> b Source # | |

HFoldable f => HFoldable (f :&: a) Source # | |

Defined in Data.Comp.Multi.Ops hfold :: Monoid m => (f :&: a) (K m) :=> m Source # hfoldMap :: forall m (a0 :: Type -> Type). Monoid m => (a0 :=> m) -> (f :&: a) a0 :=> m Source # hfoldr :: forall (a0 :: Type -> Type) b. (a0 :=> (b -> b)) -> b -> (f :&: a) a0 :=> b Source # hfoldl :: forall b (a0 :: Type -> Type). (b -> a0 :=> b) -> b -> (f :&: a) a0 :=> b Source # hfoldr1 :: (a0 -> a0 -> a0) -> (f :&: a) (K a0) :=> a0 Source # hfoldl1 :: (a0 -> a0 -> a0) -> (f :&: a) (K a0) :=> a0 Source # |

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 #

#### Instances

(All HTraversable fs, All HFoldable fs, All HFunctor fs) => HTraversable (Sum fs) Source # | |

Defined in Data.Comp.Multi.Ops | |

HTraversable f => HTraversable (Cxt h f) Source # | |

Defined in Data.Comp.Multi.Term | |

HTraversable f => HTraversable (f :&: a) Source # | |

Defined in Data.Comp.Multi.Ops hmapM :: forall (m :: Type -> Type) (a0 :: Type -> Type) (b :: Type -> Type). Monad m => NatM m a0 b -> NatM m ((f :&: a) a0) ((f :&: a) b) Source # htraverse :: forall (f0 :: Type -> Type) (a0 :: Type -> Type) (b :: Type -> Type). Applicative f0 => NatM f0 a0 b -> NatM f0 ((f :&: a) a0) ((f :&: a) b) Source # |

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 type constructor of any higher-order kind
taking at least two arguments. The smart constructors are similar to the
ordinary constructors, but an `inject`

is automatically inserted.

## Lifting to Sums

liftSum :: Name -> Q [Dec] Source #

Given the name of a type class, where the first parameter is a higher-order
functor, lift it to sums of higher-order. Example: `class HShowF f where ...`

is lifted as `instance (HShowF f, HShowF g) => HShowF (f :+: g) where ... `

.

## Generic

data GenericExample Source #