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Language	Haskell2010

Generics.Deriving.Monoid

Contents

Introduction
GMonoid type class
Default definitions
- GMonoid
Internal auxiliary class for GMonoid
- Monoid
Internal auxiliary class for Monoid
The Monoid module
Orphan instances

Synopsis

class GSemigroup a => GMonoid a where
- gmempty :: a
- gmappend :: a -> a -> a
- gmconcat :: [a] -> a
gmemptydefault :: (Generic a, GMonoid' (Rep a)) => a
gmappenddefault :: (Generic a, GMonoid' (Rep a)) => a -> a -> a
class GSemigroup' f => GMonoid' f where
- gmempty' :: f x
- gmappend' :: f x -> f x -> f x
memptydefault :: (Generic a, Monoid' (Rep a)) => a
mappenddefault :: (Generic a, Monoid' (Rep a)) => a -> a -> a
class Monoid' f where
- mempty' :: f x
- mappend' :: f x -> f x -> f x
module Data.Monoid

Introduction

This module provides two main features:

GMonoid, a generic version of the Monoid type class, including instances of the types from Data.Monoid
Default generic definitions for the Monoid methods mempty and mappend

The generic defaults only work for types without alternatives (i.e. they have only one constructor). We cannot in general know how to deal with different constructors.

GMonoid type class

class GSemigroup a => GMonoid a where #

Minimal complete definition

Nothing

Methods

gmempty :: a #

Generic mempty

default gmempty :: (Generic a, GMonoid' (Rep a)) => a #

gmappend :: a -> a -> a #

Generic mappend

default gmappend :: (Generic a, GMonoid' (Rep a)) => a -> a -> a #

gmconcat :: [a] -> a #

Generic mconcat

Instances

Instances details

GMonoid Ordering #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Ordering # gmappend :: Ordering -> Ordering -> Ordering # gmconcat :: [Ordering] -> Ordering #
GMonoid () #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: () # gmappend :: () -> () -> () # gmconcat :: [()] -> () #
GMonoid All #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: All # gmappend :: All -> All -> All # gmconcat :: [All] -> All #
GMonoid Any #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Any # gmappend :: Any -> Any -> Any # gmconcat :: [Any] -> Any #
GMonoid [a] #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: [a] # gmappend :: [a] -> [a] -> [a] # gmconcat :: [[a]] -> [a] #
GSemigroup a => GMonoid (Maybe a) #
Instance details Defined in Generics.Deriving.Monoid Methods gmempty :: Maybe a # gmappend :: Maybe a -> Maybe a -> Maybe a # gmconcat :: [Maybe a] -> Maybe a #
GMonoid m => GMonoid (WrappedMonoid m) #
Instance details Defined in Generics.Deriving.Monoid Methods gmempty :: WrappedMonoid m # gmappend :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # gmconcat :: [WrappedMonoid m] -> WrappedMonoid m #
GMonoid a => GMonoid (Identity a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Identity a # gmappend :: Identity a -> Identity a -> Identity a # gmconcat :: [Identity a] -> Identity a #
GMonoid (First a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: First a # gmappend :: First a -> First a -> First a # gmconcat :: [First a] -> First a #
GMonoid (Last a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Last a # gmappend :: Last a -> Last a -> Last a # gmconcat :: [Last a] -> Last a #
GMonoid a => GMonoid (Dual a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Dual a # gmappend :: Dual a -> Dual a -> Dual a # gmconcat :: [Dual a] -> Dual a #
GMonoid (Endo a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Endo a # gmappend :: Endo a -> Endo a -> Endo a # gmconcat :: [Endo a] -> Endo a #
Num a => GMonoid (Sum a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Sum a # gmappend :: Sum a -> Sum a -> Sum a # gmconcat :: [Sum a] -> Sum a #
Num a => GMonoid (Product a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Product a # gmappend :: Product a -> Product a -> Product a # gmconcat :: [Product a] -> Product a #
GMonoid a => GMonoid (Down a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Down a # gmappend :: Down a -> Down a -> Down a # gmconcat :: [Down a] -> Down a #
(Generic a, GMonoid' (Rep a)) => GMonoid (Default a) #
Instance details Defined in Generics.Deriving.Default Methods gmempty :: Default a # gmappend :: Default a -> Default a -> Default a # gmconcat :: [Default a] -> Default a #
GMonoid b => GMonoid (a -> b) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: a -> b # gmappend :: (a -> b) -> (a -> b) -> a -> b # gmconcat :: [a -> b] -> a -> b #
(GMonoid a, GMonoid b) => GMonoid (a, b) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b) # gmappend :: (a, b) -> (a, b) -> (a, b) # gmconcat :: [(a, b)] -> (a, b) #
GMonoid (Proxy s) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Proxy s # gmappend :: Proxy s -> Proxy s -> Proxy s # gmconcat :: [Proxy s] -> Proxy s #
(GMonoid a, GMonoid b, GMonoid c) => GMonoid (a, b, c) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b, c) # gmappend :: (a, b, c) -> (a, b, c) -> (a, b, c) # gmconcat :: [(a, b, c)] -> (a, b, c) #
GMonoid a => GMonoid (Const a b) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Const a b # gmappend :: Const a b -> Const a b -> Const a b # gmconcat :: [Const a b] -> Const a b #
Alternative f => GMonoid (Alt f a) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: Alt f a # gmappend :: Alt f a -> Alt f a -> Alt f a # gmconcat :: [Alt f a] -> Alt f a #
(GMonoid a, GMonoid b, GMonoid c, GMonoid d) => GMonoid (a, b, c, d) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b, c, d) # gmappend :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) # gmconcat :: [(a, b, c, d)] -> (a, b, c, d) #
(GMonoid a, GMonoid b, GMonoid c, GMonoid d, GMonoid e) => GMonoid (a, b, c, d, e) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b, c, d, e) # gmappend :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # gmconcat :: [(a, b, c, d, e)] -> (a, b, c, d, e) #
(GMonoid a, GMonoid b, GMonoid c, GMonoid d, GMonoid e, GMonoid f) => GMonoid (a, b, c, d, e, f) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b, c, d, e, f) # gmappend :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) # gmconcat :: [(a, b, c, d, e, f)] -> (a, b, c, d, e, f) #
(GMonoid a, GMonoid b, GMonoid c, GMonoid d, GMonoid e, GMonoid f, GMonoid g) => GMonoid (a, b, c, d, e, f, g) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b, c, d, e, f, g) # gmappend :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) # gmconcat :: [(a, b, c, d, e, f, g)] -> (a, b, c, d, e, f, g) #
(GMonoid a, GMonoid b, GMonoid c, GMonoid d, GMonoid e, GMonoid f, GMonoid g, GMonoid h) => GMonoid (a, b, c, d, e, f, g, h) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty :: (a, b, c, d, e, f, g, h) # gmappend :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) # gmconcat :: [(a, b, c, d, e, f, g, h)] -> (a, b, c, d, e, f, g, h) #

Default definitions

GMonoid

gmemptydefault :: (Generic a, GMonoid' (Rep a)) => a #

gmappenddefault :: (Generic a, GMonoid' (Rep a)) => a -> a -> a #

Internal auxiliary class for GMonoid

class GSemigroup' f => GMonoid' f where #

Methods

gmempty' :: f x #

gmappend' :: f x -> f x -> f x #

Instances

Instances details

GMonoid' (U1 :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty' :: forall (x :: k0). U1 x # gmappend' :: forall (x :: k0). U1 x -> U1 x -> U1 x #
(GMonoid' f, GMonoid' h) => GMonoid' (f :*: h :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty' :: forall (x :: k0). (f :: h) x # gmappend' :: forall (x :: k0). (f :: h) x -> (f :: h) x -> (f :: h) x #
GMonoid a => GMonoid' (K1 i a :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty' :: forall (x :: k0). K1 i a x # gmappend' :: forall (x :: k0). K1 i a x -> K1 i a x -> K1 i a x #
GMonoid' f => GMonoid' (M1 i c f :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods gmempty' :: forall (x :: k0). M1 i c f x # gmappend' :: forall (x :: k0). M1 i c f x -> M1 i c f x -> M1 i c f x #

Monoid

These functions can be used in a Monoid instance. For example:

 -- LANGUAGE DeriveGeneric

 import Generics.Deriving.Base (Generic)
 import Generics.Deriving.Monoid

 data T a = C a (Maybe a) deriving Generic

 instance Monoid a => Monoid (T a) where
   mempty  = memptydefault
   mappend = mappenddefault

memptydefault :: (Generic a, Monoid' (Rep a)) => a #

mappenddefault :: (Generic a, Monoid' (Rep a)) => a -> a -> a #

Internal auxiliary class for Monoid

class Monoid' f where #

Methods

mempty' :: f x #

mappend' :: f x -> f x -> f x #

Instances

Instances details

Monoid' (U1 :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods mempty' :: forall (x :: k0). U1 x # mappend' :: forall (x :: k0). U1 x -> U1 x -> U1 x #
(Monoid' f, Monoid' h) => Monoid' (f :*: h :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods mempty' :: forall (x :: k0). (f :: h) x # mappend' :: forall (x :: k0). (f :: h) x -> (f :: h) x -> (f :: h) x #
Monoid a => Monoid' (K1 i a :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods mempty' :: forall (x :: k0). K1 i a x # mappend' :: forall (x :: k0). K1 i a x -> K1 i a x -> K1 i a x #
Monoid' f => Monoid' (M1 i c f :: k -> Type) #
Instance details Defined in Generics.Deriving.Monoid.Internal Methods mempty' :: forall (x :: k0). M1 i c f x # mappend' :: forall (x :: k0). M1 i c f x -> M1 i c f x -> M1 i c f x #

The Monoid module

This is exported for convenient access to the various wrapper types.

module Data.Monoid

Orphan instances

GSemigroup a => GMonoid (Maybe a) #
Instance details Methods gmempty :: Maybe a # gmappend :: Maybe a -> Maybe a -> Maybe a # gmconcat :: [Maybe a] -> Maybe a #
GMonoid m => GMonoid (WrappedMonoid m) #
Instance details Methods gmempty :: WrappedMonoid m # gmappend :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # gmconcat :: [WrappedMonoid m] -> WrappedMonoid m #