| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Distribution.Compat.Semigroup
Description
Compatibility layer for Data.Semigroup
Synopsis
-
class
Semigroup
a
where
- (<>) :: a -> a -> a
- class Semigroup a => Monoid a where
- newtype All = All { }
- newtype Any = Any { }
-
newtype
First'
a =
First'
{
- getFirst' :: a
-
newtype
Last'
a =
Last'
{
- getLast' :: a
-
newtype
Option'
a =
Option'
{
- getOption' :: Maybe a
- gmappend :: ( Generic a, GSemigroup ( Rep a)) => a -> a -> a
- gmempty :: ( Generic a, GMonoid ( Rep a)) => a
Documentation
class Semigroup a where Source #
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
Since: base-4.9.0.0
Methods
(<>) :: a -> a -> a infixr 6 Source #
An associative operation.
>>>[1,2,3] <> [4,5,6][1,2,3,4,5,6]
Instances
class Semigroup a => Monoid a where Source #
The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following:
- Right identity
-
x<>mempty= x - Left identity
-
mempty<>x = x - Associativity
-
x(<>(y<>z) = (x<>y)<>zSemigrouplaw) - Concatenation
-
mconcat=foldr(<>)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define
newtype
s and make those instances
of
Monoid
, e.g.
Sum
and
Product
.
NOTE
:
Semigroup
is a superclass of
Monoid
since
base-4.11.0.0
.
Minimal complete definition
Methods
Identity of
mappend
>>>"Hello world" <> mempty"Hello world"
mappend :: a -> a -> a Source #
An associative operation
NOTE
: This method is redundant and has the default
implementation
since
base-4.11.0.0
.
Should it be implemented manually, since
mappend
= (
<>
)
mappend
is a synonym for
(
<>
), it is expected that the two functions are defined the same
way. In a future GHC release
mappend
will be removed from
Monoid
.
Fold a list using the monoid.
For most types, the default definition for
mconcat
will be
used, but the function is included in the class definition so
that an optimized version can be provided for specific types.
>>>mconcat ["Hello", " ", "Haskell", "!"]"Hello Haskell!"
Instances
Boolean monoid under conjunction (
&&
).
>>>getAll (All True <> mempty <> All False)False
>>>getAll (mconcat (map (\x -> All (even x)) [2,4,6,7,8]))False
Instances
| Bounded All |
Since: base-2.1 |
| Eq All |
Since: base-2.1 |
| Data All |
Since: base-4.8.0.0 |
|
Defined in Data.Data Methods gfoldl :: ( forall d b. Data d => c (d -> b) -> d -> c b) -> ( forall g. g -> c g) -> All -> c All Source # gunfold :: ( forall b r. Data b => c (b -> r) -> c r) -> ( forall r. r -> c r) -> Constr -> c All Source # toConstr :: All -> Constr Source # dataTypeOf :: All -> DataType Source # dataCast1 :: Typeable t => ( forall d. Data d => c (t d)) -> Maybe (c All ) Source # dataCast2 :: Typeable t => ( forall d e. ( Data d, Data e) => c (t d e)) -> Maybe (c All ) Source # gmapT :: ( forall b. Data b => b -> b) -> All -> All Source # gmapQl :: (r -> r' -> r) -> r -> ( forall d. Data d => d -> r') -> All -> r Source # gmapQr :: forall r r'. (r' -> r -> r) -> r -> ( forall d. Data d => d -> r') -> All -> r Source # gmapQ :: ( forall d. Data d => d -> u) -> All -> [u] Source # gmapQi :: Int -> ( forall d. Data d => d -> u) -> All -> u Source # gmapM :: Monad m => ( forall d. Data d => d -> m d) -> All -> m All Source # gmapMp :: MonadPlus m => ( forall d. Data d => d -> m d) -> All -> m All Source # gmapMo :: MonadPlus m => ( forall d. Data d => d -> m d) -> All -> m All Source # |
|
| Ord All |
Since: base-2.1 |
| Read All |
Since: base-2.1 |
| Show All |
Since: base-2.1 |
| Generic All |
Since: base-4.7.0.0 |
| Semigroup All |
Since: base-4.9.0.0 |
| Monoid All |
Since: base-2.1 |
| Binary All |
Since: binary-0.8.4.0 |
| NFData All |
Since: deepseq-1.4.0.0 |
|
Defined in Control.DeepSeq |
|
| type Rep All | |
|
Defined in Data.Semigroup.Internal |
|
Boolean monoid under disjunction (
||
).
>>>getAny (Any True <> mempty <> Any False)True
>>>getAny (mconcat (map (\x -> Any (even x)) [2,4,6,7,8]))True
Instances
| Bounded Any |
Since: base-2.1 |
| Eq Any |
Since: base-2.1 |
| Data Any |
Since: base-4.8.0.0 |
|
Defined in Data.Data Methods gfoldl :: ( forall d b. Data d => c (d -> b) -> d -> c b) -> ( forall g. g -> c g) -> Any -> c Any Source # gunfold :: ( forall b r. Data b => c (b -> r) -> c r) -> ( forall r. r -> c r) -> Constr -> c Any Source # toConstr :: Any -> Constr Source # dataTypeOf :: Any -> DataType Source # dataCast1 :: Typeable t => ( forall d. Data d => c (t d)) -> Maybe (c Any ) Source # dataCast2 :: Typeable t => ( forall d e. ( Data d, Data e) => c (t d e)) -> Maybe (c Any ) Source # gmapT :: ( forall b. Data b => b -> b) -> Any -> Any Source # gmapQl :: (r -> r' -> r) -> r -> ( forall d. Data d => d -> r') -> Any -> r Source # gmapQr :: forall r r'. (r' -> r -> r) -> r -> ( forall d. Data d => d -> r') -> Any -> r Source # gmapQ :: ( forall d. Data d => d -> u) -> Any -> [u] Source # gmapQi :: Int -> ( forall d. Data d => d -> u) -> Any -> u Source # gmapM :: Monad m => ( forall d. Data d => d -> m d) -> Any -> m Any Source # gmapMp :: MonadPlus m => ( forall d. Data d => d -> m d) -> Any -> m Any Source # gmapMo :: MonadPlus m => ( forall d. Data d => d -> m d) -> Any -> m Any Source # |
|
| Ord Any |
Since: base-2.1 |
| Read Any |
Since: base-2.1 |
| Show Any |
Since: base-2.1 |
| Generic Any |
Since: base-4.7.0.0 |
| Semigroup Any |
Since: base-4.9.0.0 |
| Monoid Any |
Since: base-2.1 |
| Binary Any |
Since: binary-0.8.4.0 |
| NFData Any |
Since: deepseq-1.4.0.0 |
|
Defined in Control.DeepSeq |
|
| type Rep Any | |
|
Defined in Data.Semigroup.Internal |
|
A copy of
First
.
Instances
| Eq a => Eq ( First' a) Source # | |
| Ord a => Ord ( First' a) Source # | |
|
Defined in Distribution.Compat.Semigroup |
|
| Show a => Show ( First' a) Source # | |
| Semigroup ( First' a) Source # | |
A copy of
Last
.
Instances
| Functor Last' Source # | |
| Eq a => Eq ( Last' a) Source # | |
| Ord a => Ord ( Last' a) Source # | |
|
Defined in Distribution.Compat.Semigroup |
|
| Read a => Read ( Last' a) Source # | |
| Show a => Show ( Last' a) Source # | |
| Generic ( Last' a) Source # | |
| Semigroup ( Last' a) Source # | |
| Binary a => Binary ( Last' a) Source # | |
| Structured a => Structured ( Last' a) Source # | |
|
Defined in Distribution.Compat.Semigroup |
|
| type Rep ( Last' a) Source # | |
|
Defined in Distribution.Compat.Semigroup |
|
A wrapper around
Maybe
, providing the
Semigroup
and
Monoid
instances
implemented for
Maybe
since
base-4.11
.
Constructors
| Option' | |
|
Fields
|
|
Instances
| Functor Option' Source # | |
| Eq a => Eq ( Option' a) Source # | |
| Ord a => Ord ( Option' a) Source # | |
|
Defined in Distribution.Compat.Semigroup Methods compare :: Option' a -> Option' a -> Ordering Source # (<) :: Option' a -> Option' a -> Bool Source # (<=) :: Option' a -> Option' a -> Bool Source # (>) :: Option' a -> Option' a -> Bool Source # (>=) :: Option' a -> Option' a -> Bool Source # |
|
| Read a => Read ( Option' a) Source # | |
| Show a => Show ( Option' a) Source # | |
| Generic ( Option' a) Source # | |
| Semigroup a => Semigroup ( Option' a) Source # | |
| Semigroup a => Monoid ( Option' a) Source # | |
| Binary a => Binary ( Option' a) Source # | |
| Structured a => Structured ( Option' a) Source # | |
|
Defined in Distribution.Compat.Semigroup |
|
| type Rep ( Option' a) Source # | |
|
Defined in Distribution.Compat.Semigroup |
|