Data.Monoid.Recommend

A type for representing values with an additional bit saying whether the value is "just a recommendation" (to be used only if nothing better comes along) or a "committment" (to certainly be used, overriding merely recommended values), along with corresponding Semigroup and Monoid instances.

Documentation

data Recommend a

A value of type Recommend a consists of a value of type a wrapped up in one of two constructors. The Recommend constructor indicates a "non-committal recommendation"---that is, the given value should be used if no other/better values are available. The Commit constructor indicates a "commitment"---a value which should definitely be used, overriding any Recommended values.

Constructors

Recommend a

Commit a

Instances

Functor Recommend

Methods

fmap :: (a -> b) -> Recommend a -> Recommend b

(<$) :: a -> Recommend b -> Recommend a

Foldable Recommend

Methods

fold :: Monoid m => Recommend m -> m

foldMap :: Monoid m => (a -> m) -> Recommend a -> m

foldr :: (a -> b -> b) -> b -> Recommend a -> b

foldr' :: (a -> b -> b) -> b -> Recommend a -> b

foldl :: (b -> a -> b) -> b -> Recommend a -> b

foldl' :: (b -> a -> b) -> b -> Recommend a -> b

foldr1 :: (a -> a -> a) -> Recommend a -> a

foldl1 :: (a -> a -> a) -> Recommend a -> a

toList :: Recommend a -> [a]

null :: Recommend a -> Bool

length :: Recommend a -> Int

elem :: Eq a => a -> Recommend a -> Bool

maximum :: Ord a => Recommend a -> a

minimum :: Ord a => Recommend a -> a

sum :: Num a => Recommend a -> a

product :: Num a => Recommend a -> a

Traversable Recommend

Methods

traverse :: Applicative f => (a -> f b) -> Recommend a -> f (Recommend b)

sequenceA :: Applicative f => Recommend (f a) -> f (Recommend a)

mapM :: Monad m => (a -> m b) -> Recommend a -> m (Recommend b)

sequence :: Monad m => Recommend (m a) -> m (Recommend a)

Eq a => Eq (Recommend a)

Methods

(==) :: Recommend a -> Recommend a -> Bool

(/=) :: Recommend a -> Recommend a -> Bool

Data a => Data (Recommend a)

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Recommend a -> c (Recommend a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Recommend a)

toConstr :: Recommend a -> Constr

dataTypeOf :: Recommend a -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c (Recommend a))

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Recommend a))

gmapT :: (forall b. Data b => b -> b) -> Recommend a -> Recommend a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Recommend a -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Recommend a -> r

gmapQ :: (forall d. Data d => d -> u) -> Recommend a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Recommend a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Recommend a -> m (Recommend a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Recommend a -> m (Recommend a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Recommend a -> m (Recommend a)

Ord a => Ord (Recommend a)

Methods

compare :: Recommend a -> Recommend a -> Ordering

(<) :: Recommend a -> Recommend a -> Bool

(<=) :: Recommend a -> Recommend a -> Bool

(>) :: Recommend a -> Recommend a -> Bool

(>=) :: Recommend a -> Recommend a -> Bool

max :: Recommend a -> Recommend a -> Recommend a

min :: Recommend a -> Recommend a -> Recommend a

Read a => Read (Recommend a)

Methods

readsPrec :: Int -> ReadS (Recommend a)

readList :: ReadS [Recommend a]

readPrec :: ReadPrec (Recommend a)

readListPrec :: ReadPrec [Recommend a]

Show a => Show (Recommend a)

Methods

showsPrec :: Int -> Recommend a -> ShowS

show :: Recommend a -> String

showList :: [Recommend a] -> ShowS

Semigroup a => Semigroup (Recommend a)

Commit overrides Recommend. Two values wrapped in the same constructor (both Recommend or both Commit) are combined according to the underlying Semigroup instance.

Methods

(<>) :: Recommend a -> Recommend a -> Recommend a

sconcat :: NonEmpty (Recommend a) -> Recommend a

stimes :: Integral b => b -> Recommend a -> Recommend a

(Semigroup a, Monoid a) => Monoid (Recommend a)

Methods

mempty :: Recommend a

mappend :: Recommend a -> Recommend a -> Recommend a

mconcat :: [Recommend a] -> Recommend a

getRecommend :: Recommend a -> a

Extract the value of type a wrapped in Recommend a.