Attachment 594249 Details for Bug 834069 – test.icl

test.icl

test.icl (text/plain), 1.11 KB, created by Patrick Uiterwijk on 2012-06-25 17:56:17 UTC

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Creator: Patrick Uiterwijk

Created: 2012-06-25 17:56:17 UTC

Size: 1.11 KB

patch

obsolete

>module test
>
>import StdEnv
>
>:: Nat = Zero | S Nat
>
>Start = toInt ((((getNat 1) + (getNat 2)) * (getNat 3)) ^ (getNat 4))
>
>
>instance zero Nat
>where
>	zero :: Nat
>	zero = Zero
>
>instance one Nat
>where
>	one :: Nat
>	one = S Zero
>
>instance toInt Nat
>where
>	toInt :: !Nat -> Int
>	toInt Zero	= 0
>	toInt (S n)	= 1 + (toInt n)
>
>instance fromInt Nat
>where
>	fromInt :: !Int -> Nat
>	fromInt 0	= zero
>	fromInt x	= S (fromInt (x-1))
>
>instance == Nat
>where
>	(==) :: !Nat !Nat -> Bool
>	(==) Zero Zero	= True
>	(==) Zero _	= False
>	(==) _ Zero	= False
>	(==) (S m) (S n)= m == n
>
>instance < Nat
>where
>	(<) :: !Nat !Nat -> Bool
>	(<) Zero Zero	= False
>	(<) Zero _	= True
>	(<) _ Zero	= False
>	(<) (S m) (S n)	= m < n
>
>instance isEven Nat
>where
>	isEven :: !Nat -> Bool
>	isEven Zero	= True
>	isEven (S Zero)	= False
>	isEven (S (S n))= isEven n
>
>instance + Nat
>where
>	(+) :: !Nat !Nat -> Nat
>	(+) m Zero	= m
>	(+) m (S n)	= S (m + n)
>
>instance * Nat
>where
>	(*) :: !Nat !Nat -> Nat
>	(*) m Zero	= zero
>	(*) m (S n)	= m + (m * n)
>
>instance ^ Nat
>where
>	(^) :: !Nat !Nat -> Nat
>	(^) m Zero	= one
>	(^) m (S n)	= m * (m ^ n)
>
>getNat :: !Int -> Nat
>getNat n	= fromInt n

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