module Database.Selda.Types where
import Data.Text (Text)
import Data.Typeable
type ColName = Text
type TableName = Text
data a :*: b where
(:*:) :: a -> b -> a :*: b
deriving Typeable
infixr 1 :*:
instance (Show a, Show b) => Show (a :*: b) where
show (a :*: b) = show a ++ " :*: " ++ show b
instance (Eq a, Eq b) => Eq (a :*: b) where
(a :*: b) == (a' :*: b') = a == a' && b == b'
instance (Ord a, Ord b) => Ord (a :*: b) where
(a :*: b) `compare` (a' :*: b') =
case a `compare` a' of
EQ -> b `compare` b'
o -> o
type family Head a where
Head (a :*: b) = a
Head a = a
class Tup a where
tupHead :: a -> Head a
instance Tup (a :*: b) where
tupHead (a :*: _) = a
instance Head a ~ a => Tup a where
tupHead a = a
first :: Tup a => a -> Head a
first = tupHead
second :: Tup b => (a :*: b) -> Head b
second (_ :*: b) = tupHead b
third :: Tup c => (a :*: b :*: c) -> Head c
third (_ :*: _ :*: c) = tupHead c
fourth :: Tup d => (a :*: b :*: c :*: d) -> Head d
fourth (_ :*: _ :*: _ :*: d) = tupHead d
fifth :: Tup e => (a :*: b :*: c :*: d :*: e) -> Head e
fifth (_ :*: _ :*: _ :*: _ :*: e) = tupHead e
sixth :: Tup f => (a :*: b :*: c :*: d :*: e :*: f) -> Head f
sixth (_ :*: _ :*: _ :*: _ :*: _ :*: f) = tupHead f
seventh :: Tup g => (a :*: b :*: c :*: d :*: e :*: f :*: g) -> Head g
seventh (_ :*: _ :*: _ :*: _ :*: _ :*: _ :*: g) = tupHead g
eighth :: Tup h => (a :*: b :*: c :*: d :*: e :*: f :*: g :*: h) -> Head h
eighth (_ :*: _ :*: _ :*: _ :*: _ :*: _ :*: _ :*: h) = tupHead h
ninth :: Tup i => (a :*: b :*: c :*: d :*: e :*: f :*: h :*: h :*: i) -> Head i
ninth (_ :*: _ :*: _ :*: _ :*: _ :*: _ :*: _ :*: _ :*: i) = tupHead i
tenth :: Tup j => (a :*: b :*: c :*: d :*: e :*: f :*: g :*: h :*: i :*: j)
-> Head j
tenth (_ :*: _ :*: _ :*: _ :*: _ :*: _ :*: _ :*: _ :*: _ :*: j) = tupHead j