import Data.Vector.Fixed (
Dim,
- Fun(..),
N1,
- N2,
- N3,
N4,
+ N5,
+ S,
Vector(..),
- construct,
- inspect,
+ fromList,
toList,
)
import qualified Data.Vector.Fixed as V (
+ (!),
length,
)
+import Data.Vector.Fixed.Boxed
+type Vec1 = Vec N1
+type Vec4 = Vec N4
+type Vec5 = Vec N5
--- * Low-dimension vector wrappers.
---
--- These wrappers are instances of 'Vector', so they inherit all of
--- the userful instances defined above. But, they use fixed
--- constructors, so you can pattern match out the individual
--- components.
-
-data D1 a = D1 a
-type instance Dim D1 = N1
-instance Vector D1 a where
- inspect (D1 x) (Fun f) = f x
- construct = Fun D1
-
-data D2 a = D2 a a
-type instance Dim D2 = N2
-instance Vector D2 a where
- inspect (D2 x y) (Fun f) = f x y
- construct = Fun D2
-
-data D3 a = D3 a a a
-type instance Dim D3 = N3
-instance Vector D3 a where
- inspect (D3 x y z) (Fun f) = f x y z
- construct = Fun D3
-data D4 a = D4 a a a a
-type instance Dim D4 = N4
-instance Vector D4 a where
- inspect (D4 w x y z) (Fun f) = f w x y z
- construct = Fun D4
-
-
--- | Unsafe indexing.
---
--- Examples:
---
--- >>> let v1 = D2 1 2
--- >>> v1 ! 1
--- 2
---
-(!) :: (Vector v a) => v a -> Int -> a
-(!) v1 idx = (toList v1) !! idx
-- | Safe indexing.
--
-- Examples:
--
--- >>> let v1 = D3 1 2 3
+-- >>> import Data.Vector.Fixed (mk3)
+-- >>> let v1 = mk3 1 2 3 :: Vec3 Int
-- >>> v1 !? 2
-- Just 3
-- >>> v1 !? 3
(!?) :: (Vector v a) => v a -> Int -> Maybe a
(!?) v1 idx
| idx < 0 || idx >= V.length v1 = Nothing
- | otherwise = Just $ v1 ! idx
+ | otherwise = Just $ v1 V.! idx
+
+
+-- | Remove an element of the given vector.
+--
+-- Examples:
+--
+-- >>> import Data.Vector.Fixed (mk3)
+-- >>> let b = mk3 1 2 3 :: Vec3 Int
+-- >>> delete b 1 :: Vec2 Int
+-- fromList [1,3]
+--
+delete :: (Vector v a,
+ Vector w a,
+ Dim v ~ S (Dim w))
+ => v a
+ -> Int
+ -> w a
+delete v1 idx =
+ fromList (lhalf ++ rhalf')
+ where
+ (lhalf, rhalf) = splitAt idx (toList v1)
+ rhalf' = tail rhalf