Copyright	(c) 2012-2015 diagrams-core team (see LICENSE)
License	BSD-style (see LICENSE)
Maintainer	diagrams-discuss@googlegroups.com
Safe Haskell	Safe
Language	Haskell2010

Data.Monoid.Recommend

Description

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 "commitment" (to certainly be used, overriding merely recommended values), along with corresponding Semigroup and Monoid instances.

Synopsis

data Recommend a
- = Recommend a
- | Commit a
getRecommend :: Recommend a -> a

Documentation

data Recommend a Source #

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 Source #
Instance details Defined in Data.Monoid.Recommend Methods fmap :: (a -> b) -> Recommend a -> Recommend b # (<$) :: a -> Recommend b -> Recommend a #
Foldable Recommend Source #
Instance details Defined in Data.Monoid.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 Source #
Instance details Defined in Data.Monoid.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) Source #
Instance details Defined in Data.Monoid.Recommend Methods (==) :: Recommend a -> Recommend a -> Bool # (/=) :: Recommend a -> Recommend a -> Bool #
Data a => Data (Recommend a) Source #
Instance details Defined in Data.Monoid.Recommend 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) Source #
Instance details Defined in Data.Monoid.Recommend 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) Source #
Instance details Defined in Data.Monoid.Recommend Methods readsPrec :: Int -> ReadS (Recommend a) # readList :: ReadS [Recommend a] # readPrec :: ReadPrec (Recommend a) # readListPrec :: ReadPrec [Recommend a] #
Show a => Show (Recommend a) Source #
Instance details Defined in Data.Monoid.Recommend Methods showsPrec :: Int -> Recommend a -> ShowS # show :: Recommend a -> String # showList :: [Recommend a] -> ShowS #
Semigroup a => Semigroup (Recommend a) Source #	`Commit` overrides `Recommend`. Two values wrapped in the same constructor (both `Recommend` or both `Commit`) are combined according to the underlying `Semigroup` instance.
Instance details Defined in Data.Monoid.Recommend 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) Source #
Instance details Defined in Data.Monoid.Recommend Methods mempty :: Recommend a # mappend :: Recommend a -> Recommend a -> Recommend a # mconcat :: [Recommend a] -> Recommend a #

getRecommend :: Recommend a -> a Source #

Extract the value of type a wrapped in Recommend a.