On Fri, 07 Jan 2005 18:57:01 -0600, Jaime Nino <[EMAIL PROTECTED]> wrote:
> where value is the last value of a.
^^^^^^^^^^^^^^^^
> I have not found any functionality on Enum types to do this. In
> particular how to
> specify the last element of any Enum type, or how to determine the
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> number of elements in an Enum type.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
It looks as if you really want to use the type class Bounded as well.
You can use maxBound and minBound to find the last and first value of
a Bounded type.
If you impose the additional constraint Eq and Bounded you can write
next like so:
next :: (Enum a, Bounded a, Eq a) => a -> a
next x | x == maxBound = minBound
| otherwise = succ x
/S
--
Sebastian Sylvan
+46(0)736-818655
UIN: 44640862
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