module Graphics.Xournal.Render.Type.Hitted where
import Data.Xournal.BBox
import Prelude hiding (fst,snd)
data AlterList a b = Empty | a :- AlterList b a
deriving (Show)
infixr 6 :-
newtype NotHitted a = NotHitted { unNotHitted :: [a] }
deriving (Show)
newtype Hitted a = Hitted { unHitted :: [a] }
deriving (Show)
type StrokeHitted = AlterList (NotHitted StrokeBBox) (Hitted StrokeBBox)
fmapAL :: (a -> c) -> (b -> d) -> AlterList a b -> AlterList c d
fmapAL _ _ Empty = Empty
fmapAL f g (x :- ys) = f x :- fmapAL g f ys
getA :: AlterList a b -> [a]
getA Empty = []
getA (x :- xs) = x : getB xs
getB :: AlterList a b -> [b]
getB Empty = []
getB (_x :- xs) = getA xs
interleave :: (a->c) -> (b->c) -> AlterList a b -> [c]
interleave _fa _fb Empty = []
interleave fa fb (x :- xs) = fa x : (interleave fb fa xs)
type TAlterHitted a = AlterList [a] (Hitted a)
newtype TEitherAlterHitted a =
TEitherAlterHitted {
unTEitherAlterHitted :: Either [a] (TAlterHitted a)
}