On 09 Jan 2005 07:56:58 +0100, Peter Simons <[EMAIL PROTECTED]> wrote: > Jaime Nino writes: > > > I would like to write a function with type > > next :: Enum a => a -> a > > which will wrap a values around [...]. > > You'll need (Bounded a, Enum a) to implement that. The > function you are looking for is 'maxBound'. Enumerable types > are not necessarily bounded in the general case, just think > of the natural numbers for an example of an enumerable set > that is not. >
He'll also need Eq a, right? How else does he investigate wether the value is equal to maxBound? One could use exceptions, I suppose, and catch the exception which arises from trying to use succ on maxBound. But then you'll need to be in the IO monad, unless you use unsafePerformIO =) /S -- Sebastian Sylvan +46(0)736-818655 UIN: 44640862 _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
