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mirror of https://github.com/idris-lang/Idris2.git synced 2024-12-16 15:52:43 +03:00
Idris2/tests/idris2/basic001/Vect.idr
Edwin Brady a972778eab Add test script
They don't all pass yet, for minor reasons. Coming shortly...
Unfortunately the startup overhead for chez is really noticeable here!
2020-05-19 18:25:18 +01:00

35 lines
918 B
Idris

data Nat = Z | S Nat
plus : Nat -> Nat -> Nat
plus Z y = y
plus (S k) y = S (plus k y)
data Vect : Nat -> Type -> Type where
Nil : Vect Z a
Cons : a -> Vect k a -> Vect (S k) a
foldl : (0 b : Nat -> Type) ->
({k : Nat} -> b k -> a -> b (S k)) ->
b Z ->
Vect n a -> b n
foldl b g z Nil = z
foldl b g z (Cons x xs) = foldl (\i => b (S i)) g (g z x) xs
reverse : Vect n a -> Vect n a
reverse
= foldl (\m => Vect m a)
(\rev => \x => Cons x rev) Nil
append : Vect n a -> Vect m a -> Vect (plus n m) a
append Nil ys = ys
append (Cons x xs) ys = Cons x (append xs ys)
vlength : (n : Nat) -> Vect n a -> Nat
vlength Z Nil = Z
vlength n@_ (Cons x xs) = n -- (vlength _ xs);
zipWith : (a -> b -> c) -> Vect n a -> Vect n b -> Vect n c
zipWith f Nil Nil = Nil
-- zipWith f (Cons x xs) Nil impossible
zipWith f (Cons x xs) (Cons y ys) = Cons (f x y) (zipWith f xs ys)