Data.Monoid.Null

This module defines the MonoidNull class and some of its instances.

Documentation

class Monoid m => MonoidNull m where

Extension of Monoid that allows testing a value for equality with mempty. The following law must hold:

null x == (x == mempty)

Furthermore, the performance of this method should be constant, i.e., independent of the length of its argument.

Minimal complete definition

Nothing

Methods

null :: m -> Bool

default null :: Eq m => m -> Bool

Instances

MonoidNull All

Defined in Data.Monoid.Null

Methods

null :: All -> Bool

MonoidNull Any

Defined in Data.Monoid.Null

Methods

null :: Any -> Bool

MonoidNull ByteString

Defined in Data.Monoid.Null

Methods

null :: ByteString -> Bool

MonoidNull ByteString

Defined in Data.Monoid.Null

Methods

null :: ByteString -> Bool

MonoidNull IntSet

Defined in Data.Monoid.Null

Methods

null :: IntSet -> Bool

MonoidNull Ordering

Defined in Data.Monoid.Null

Methods

null :: Ordering -> Bool

MonoidNull ByteStringUTF8

O(1)

Defined in Data.Monoid.Instances.ByteString.UTF8

Methods

null :: ByteStringUTF8 -> Bool

MonoidNull Text

Defined in Data.Monoid.Null

Methods

null :: Text -> Bool

MonoidNull Text

Defined in Data.Monoid.Null

Methods

null :: Text -> Bool

MonoidNull ()

Defined in Data.Monoid.Null

Methods

null :: () -> Bool

MonoidNull a => MonoidNull (Identity a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Identity a -> Bool

MonoidNull (First a)

Defined in Data.Monoid.Null

Methods

null :: First a -> Bool

MonoidNull (Last a)

Defined in Data.Monoid.Null

Methods

null :: Last a -> Bool

MonoidNull a => MonoidNull (Down a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Down a -> Bool

(Ord a, Bounded a) => MonoidNull (Max a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Max a -> Bool

(Ord a, Bounded a) => MonoidNull (Min a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Min a -> Bool

MonoidNull a => MonoidNull (WrappedMonoid a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: WrappedMonoid a -> Bool

MonoidNull a => MonoidNull (Dual a)

Defined in Data.Monoid.Null

Methods

null :: Dual a -> Bool

(Num a, Eq a) => MonoidNull (Product a)

Defined in Data.Monoid.Null

Methods

null :: Product a -> Bool

(Num a, Eq a) => MonoidNull (Sum a)

Defined in Data.Monoid.Null

Methods

null :: Sum a -> Bool

MonoidNull p => MonoidNull (Par1 p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Par1 p -> Bool

MonoidNull (IntMap v)

Defined in Data.Monoid.Null

Methods

null :: IntMap v -> Bool

MonoidNull (Seq a)

Defined in Data.Monoid.Null

Methods

null :: Seq a -> Bool

Ord a => MonoidNull (Set a)

Defined in Data.Monoid.Null

Methods

null :: Set a -> Bool

PositiveMonoid a => MonoidNull (Concat a)

Defined in Data.Monoid.Instances.Concat

Methods

null :: Concat a -> Bool

(StableFactorial a, Monoid a) => MonoidNull (Measured a)

Defined in Data.Monoid.Instances.Measured

Methods

null :: Measured a -> Bool

(StableFactorial m, TextualMonoid m, MonoidNull m) => MonoidNull (LinePositioned m)

Defined in Data.Monoid.Instances.Positioned

Methods

null :: LinePositioned m -> Bool

(StableFactorial m, FactorialMonoid m) => MonoidNull (OffsetPositioned m)

Defined in Data.Monoid.Instances.Positioned

Methods

null :: OffsetPositioned m -> Bool

(MonoidNull m, StableFactorial m) => MonoidNull (Shadowed m)

Defined in Data.Monoid.Instances.PrefixMemory

Methods

null :: Shadowed m -> Bool

MonoidNull (Vector a)

Defined in Data.Monoid.Null

Methods

null :: Vector a -> Bool

Monoid a => MonoidNull (Maybe a)

Defined in Data.Monoid.Null

Methods

null :: Maybe a -> Bool

MonoidNull [x]

Defined in Data.Monoid.Null

Methods

null :: [x] -> Bool

MonoidNull (Proxy a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Proxy a -> Bool

MonoidNull (U1 p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: U1 p -> Bool

Ord k => MonoidNull (Map k v)

Defined in Data.Monoid.Null

Methods

null :: Map k v -> Bool

(MonoidNull a, MonoidNull b) => MonoidNull (Stateful a b)

Defined in Data.Monoid.Instances.Stateful

Methods

null :: Stateful a b -> Bool

(MonoidNull a, MonoidNull b) => MonoidNull (a, b)

Defined in Data.Monoid.Null

Methods

null :: (a, b) -> Bool

MonoidNull r => MonoidNull (Const r a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Const r a -> Bool

MonoidNull (f p) => MonoidNull (Rec1 f p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Rec1 f p -> Bool

(MonoidNull a, MonoidNull b, MonoidNull c) => MonoidNull (a, b, c)

Defined in Data.Monoid.Null

Methods

null :: (a, b, c) -> Bool

(MonoidNull (f a), MonoidNull (g a)) => MonoidNull (Product f g a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Product f g a -> Bool

(MonoidNull (f p), MonoidNull (g p)) => MonoidNull ((f :*: g) p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: (f :*: g) p -> Bool

MonoidNull c => MonoidNull (K1 i c p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: K1 i c p -> Bool

(MonoidNull a, MonoidNull b, MonoidNull c, MonoidNull d) => MonoidNull (a, b, c, d)

Defined in Data.Monoid.Null

Methods

null :: (a, b, c, d) -> Bool

MonoidNull (f (g a)) => MonoidNull (Compose f g a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: Compose f g a -> Bool

MonoidNull (f (g p)) => MonoidNull ((f :.: g) p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: (f :.: g) p -> Bool

MonoidNull (f p) => MonoidNull (M1 i c f p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: M1 i c f p -> Bool

(MonoidNull a, MonoidNull b, MonoidNull c, MonoidNull d, MonoidNull e) => MonoidNull (a, b, c, d, e)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Methods

null :: (a, b, c, d, e) -> Bool

class MonoidNull m => PositiveMonoid m

Subclass of Monoid for types whose values have no inverse, with the exception of mempty. More formally, the class instances must satisfy the following law:

null (x <> y) == (null x && null y)

Instances

PositiveMonoid All

Defined in Data.Monoid.Null

PositiveMonoid Any

Defined in Data.Monoid.Null

PositiveMonoid ByteString

Defined in Data.Monoid.Null

PositiveMonoid ByteString

Defined in Data.Monoid.Null

PositiveMonoid IntSet

Defined in Data.Monoid.Null

PositiveMonoid Ordering

Defined in Data.Monoid.Null

PositiveMonoid ByteStringUTF8

Defined in Data.Monoid.Instances.ByteString.UTF8

PositiveMonoid Text

Defined in Data.Monoid.Null

PositiveMonoid Text

Defined in Data.Monoid.Null

PositiveMonoid ()

Defined in Data.Monoid.Null

PositiveMonoid a => PositiveMonoid (Identity a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (First a)

Defined in Data.Monoid.Null

PositiveMonoid (Last a)

Defined in Data.Monoid.Null

PositiveMonoid a => PositiveMonoid (Down a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

(Ord a, Bounded a) => PositiveMonoid (Max a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

(Ord a, Bounded a) => PositiveMonoid (Min a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid a => PositiveMonoid (WrappedMonoid a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid a => PositiveMonoid (Dual a)

Defined in Data.Monoid.Null

PositiveMonoid (Product Natural)

Defined in Data.Monoid.Null

PositiveMonoid (Sum Natural)

Defined in Data.Monoid.Null

PositiveMonoid p => PositiveMonoid (Par1 p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (IntMap v)

Defined in Data.Monoid.Null

PositiveMonoid (Seq a)

Defined in Data.Monoid.Null

Ord a => PositiveMonoid (Set a)

Defined in Data.Monoid.Null

PositiveMonoid a => PositiveMonoid (Concat a)

Defined in Data.Monoid.Instances.Concat

(StableFactorial a, Monoid a) => PositiveMonoid (Measured a)

Defined in Data.Monoid.Instances.Measured

(StableFactorial m, TextualMonoid m) => PositiveMonoid (LinePositioned m)

Defined in Data.Monoid.Instances.Positioned

(StableFactorial m, FactorialMonoid m) => PositiveMonoid (OffsetPositioned m)

Defined in Data.Monoid.Instances.Positioned

(PositiveMonoid m, StableFactorial m) => PositiveMonoid (Shadowed m)

Defined in Data.Monoid.Instances.PrefixMemory

PositiveMonoid (Vector a)

Defined in Data.Monoid.Null

Monoid a => PositiveMonoid (Maybe a)

Defined in Data.Monoid.Null

PositiveMonoid [x]

Defined in Data.Monoid.Null

PositiveMonoid (Proxy a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (U1 p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

Ord k => PositiveMonoid (Map k v)

Defined in Data.Monoid.Null

(PositiveMonoid a, PositiveMonoid b) => PositiveMonoid (Stateful a b)

Defined in Data.Monoid.Instances.Stateful

PositiveMonoid r => PositiveMonoid (Const r a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (f p) => PositiveMonoid (Rec1 f p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid c => PositiveMonoid (K1 i c p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (f (g a)) => PositiveMonoid (Compose f g a)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (f (g p)) => PositiveMonoid ((f :.: g) p)

Since: 1.2.5.0

Defined in Data.Monoid.Null

PositiveMonoid (f p) => PositiveMonoid (M1 i c f p)

Since: 1.2.5.0

Defined in Data.Monoid.Null