Pixel <[EMAIL PROTECTED]> writes:
> Quite a few pbs with overflow on Int too:
> i :: Int
> i = 0x7fffffff
> i_plus_1 = i+1
> -- ghc : -2147483648
> -- hugs: -2147483648
Given that Int represents modulo arithmetic, this is all right, but
> i_succ = succ i
> -- ghc : *** Exception: Prelude.Enum.succ{Int}: tried to take `succ' of maxBound
> -- hugs: -2147483648
GHC's behavior here is inconsequent, I think. I suppose it is trying
to maintain the invariant
succ i > i
> j :: Int
> j = 0x80000000
> -- ghc : -2147483648
> -- hugs: Program error: {primIntegerToInt 2147483648}
I'm not sure which behavior I prefer. You're specifying a constant
out of range for the datatype.
> k :: Int
> k = 0x100000000
> -- ghc : 0
> -- hugs: Program error: {primIntegerToInt 4294967296}
Same as above.
> i':: Integer
> i'= 0x7fffffff
> i_plus_1' = i+1
> -- ghc : 2147483648
> -- hugs: 2147483648
> i_succ' = succ i'
> -- ghc : 2147483648
> -- hugs: -2147483648
I think Hugs is wrong. Integer shouldn't wrap.
The greatest problem with Integer seem to be different
implementations, IMHO.
-kzm
--
If I haven't seen further, it is by standing in the footprints of giants
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