mirror of
https://github.com/idris-lang/Idris2.git
synced 2024-12-19 09:12:34 +03:00
26 lines
501 B
Idris
26 lines
501 B
Idris
%hide Prelude.integerToNat
|
|
|
|
data MyNat : Type where
|
|
Z : MyNat
|
|
S : MyNat -> MyNat
|
|
|
|
%builtin Natural MyNat
|
|
|
|
integerToMyNat : Integer -> MyNat
|
|
integerToMyNat i = if i <= 0
|
|
then Z
|
|
else S $ integerToMyNat (i - 1)
|
|
|
|
%builtin IntegerToNatural integerToMyNat
|
|
|
|
natToMyNat : Nat -> MyNat
|
|
natToMyNat Z = Z
|
|
natToMyNat (S k) = S $ natToMyNat k
|
|
|
|
%builtin IntegerToNatural natToMyNat
|
|
|
|
integerToNotNat : Integer -> Maybe String
|
|
integerToNotNat x = Just "Boo"
|
|
|
|
%builtin IntegerToNatural integerToNotNat
|