{-# LANGUAGE CPP #-}
module Data.Agreement (
Agreement(..),
getSomebody,
) where
#if MIN_VERSION_GLASGOW_HASKELL(9,6,0,0)
#else
import Control.Applicative (liftA2)
#endif
import Data.Semigroup (Semigroup(..),
stimesIdempotentMonoid)
data Agreement a = Anybody | Somebody a | Nobody
deriving (Agreement a -> Agreement a -> Bool
forall a. Eq a => Agreement a -> Agreement a -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: Agreement a -> Agreement a -> Bool
$c/= :: forall a. Eq a => Agreement a -> Agreement a -> Bool
== :: Agreement a -> Agreement a -> Bool
$c== :: forall a. Eq a => Agreement a -> Agreement a -> Bool
Eq, Agreement a -> Agreement a -> Bool
Agreement a -> Agreement a -> Ordering
forall a.
Eq a
-> (a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
forall {a}. Ord a => Eq (Agreement a)
forall a. Ord a => Agreement a -> Agreement a -> Bool
forall a. Ord a => Agreement a -> Agreement a -> Ordering
forall a. Ord a => Agreement a -> Agreement a -> Agreement a
min :: Agreement a -> Agreement a -> Agreement a
$cmin :: forall a. Ord a => Agreement a -> Agreement a -> Agreement a
max :: Agreement a -> Agreement a -> Agreement a
$cmax :: forall a. Ord a => Agreement a -> Agreement a -> Agreement a
>= :: Agreement a -> Agreement a -> Bool
$c>= :: forall a. Ord a => Agreement a -> Agreement a -> Bool
> :: Agreement a -> Agreement a -> Bool
$c> :: forall a. Ord a => Agreement a -> Agreement a -> Bool
<= :: Agreement a -> Agreement a -> Bool
$c<= :: forall a. Ord a => Agreement a -> Agreement a -> Bool
< :: Agreement a -> Agreement a -> Bool
$c< :: forall a. Ord a => Agreement a -> Agreement a -> Bool
compare :: Agreement a -> Agreement a -> Ordering
$ccompare :: forall a. Ord a => Agreement a -> Agreement a -> Ordering
Ord, Int -> Agreement a -> ShowS
forall a. Show a => Int -> Agreement a -> ShowS
forall a. Show a => [Agreement a] -> ShowS
forall a. Show a => Agreement a -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [Agreement a] -> ShowS
$cshowList :: forall a. Show a => [Agreement a] -> ShowS
show :: Agreement a -> String
$cshow :: forall a. Show a => Agreement a -> String
showsPrec :: Int -> Agreement a -> ShowS
$cshowsPrec :: forall a. Show a => Int -> Agreement a -> ShowS
Show)
getSomebody :: Agreement a -> Maybe a
getSomebody :: forall a. Agreement a -> Maybe a
getSomebody (Somebody a
x) = forall a. a -> Maybe a
Just a
x
getSomebody Agreement a
_ = forall a. Maybe a
Nothing
instance Functor Agreement where
fmap :: forall a b. (a -> b) -> Agreement a -> Agreement b
fmap a -> b
_ Agreement a
Anybody = forall a. Agreement a
Anybody
fmap a -> b
f (Somebody a
x) = forall a. a -> Agreement a
Somebody (a -> b
f a
x)
fmap a -> b
_ Agreement a
Nobody = forall a. Agreement a
Nobody
instance Applicative Agreement where
pure :: forall a. a -> Agreement a
pure = forall a. a -> Agreement a
Somebody
Agreement (a -> b)
Nobody <*> :: forall a b. Agreement (a -> b) -> Agreement a -> Agreement b
<*> Agreement a
_ = forall a. Agreement a
Nobody
Agreement (a -> b)
Anybody <*> Agreement a
_ = forall a. Agreement a
Anybody
Somebody a -> b
f <*> Agreement a
x = a -> b
f forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Agreement a
x
liftA2 :: forall a b c.
(a -> b -> c) -> Agreement a -> Agreement b -> Agreement c
liftA2 a -> b -> c
_ Agreement a
Nobody Agreement b
_ = forall a. Agreement a
Nobody
liftA2 a -> b -> c
_ Agreement a
Anybody Agreement b
_ = forall a. Agreement a
Anybody
liftA2 a -> b -> c
f (Somebody a
x) Agreement b
y = a -> b -> c
f a
x forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Agreement b
y
instance Monad Agreement where
return :: forall a. a -> Agreement a
return = forall (f :: * -> *) a. Applicative f => a -> f a
pure
Agreement a
Nobody >>= :: forall a b. Agreement a -> (a -> Agreement b) -> Agreement b
>>= a -> Agreement b
_ = forall a. Agreement a
Nobody
Agreement a
Anybody >>= a -> Agreement b
_ = forall a. Agreement a
Anybody
Somebody a
x >>= a -> Agreement b
f = a -> Agreement b
f a
x
instance (Eq a) => Semigroup (Agreement a) where
Agreement a
Nobody <> :: Agreement a -> Agreement a -> Agreement a
<> Agreement a
_ = forall a. Agreement a
Nobody
Agreement a
Anybody <> Agreement a
x = Agreement a
x
Somebody a
_ <> Agreement a
Nobody = forall a. Agreement a
Nobody
Somebody a
x <> Agreement a
Anybody = forall a. a -> Agreement a
Somebody a
x
Somebody a
x <> Somebody a
y
| a
x forall a. Eq a => a -> a -> Bool
== a
y = forall a. a -> Agreement a
Somebody a
x
| Bool
otherwise = forall a. Agreement a
Nobody
stimes :: forall b. Integral b => b -> Agreement a -> Agreement a
stimes = forall b a. (Integral b, Monoid a) => b -> a -> a
stimesIdempotentMonoid
instance (Eq a) => Monoid (Agreement a) where
mempty :: Agreement a
mempty = forall a. Agreement a
Anybody