On Jul 23, 2010, at 12:21 AM, Chad Scherrer wrote:
bdRangeSize :: (Ix i, Bounded i) => i -> Int
bdRangeSize _ = rangeSize (minBound, maxBound :: i)
Unlike intended, the `i` in the type annotation to `maxBound` is not
the same as the `i` in the signature of `bdRangeSize`. You need to
enable ScopedTypeVariables and explicitly quantify the type variable
`i` in order to refer to it in the annotation of `maxBound`:
{-# LANGUAGE ScopedTypeVariables #-}
import Data.Ix
bdRangeSize :: forall i . (Ix i, Bounded i) => i -> Int
bdRangeSize _ = rangeSize (minBound, maxBound :: i)
Cheers,
Sebastian
--
Underestimating the novelty of the future is a time-honored tradition.
(D.G.)
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