mirror of
https://github.com/idris-lang/Idris2.git
synced 2024-12-01 01:09:03 +03:00
27 lines
539 B
Idris
27 lines
539 B
Idris
%default partial
|
|
|
|
foo : Maybe a -> a
|
|
foo (Just x) = x
|
|
|
|
data Vect : ? -> Type -> Type where
|
|
Nil : Vect Z a
|
|
(::) : a -> Vect k a -> Vect (S k) a
|
|
|
|
data Fin : Nat -> Type where
|
|
FZ : Fin (S k)
|
|
FS : Fin k -> Fin (S k)
|
|
|
|
lookup : Fin n -> Vect n a -> a
|
|
lookup FZ (x :: xs) = x
|
|
lookup (FS k) (x :: xs) = lookup k xs
|
|
|
|
lookup' : Fin n -> Vect n a -> a
|
|
lookup' (FS k) (x :: xs) = lookup' k xs
|
|
|
|
lookup'' : Fin n -> Vect n a -> a
|
|
lookup'' n xs = lookup' n xs
|
|
|
|
main : IO ()
|
|
main = do let x = foo Nothing
|
|
printLn (the Int x)
|