Foldable & Traversable instances for ((,) a)
Merijn Verstraaten
merijn at inconsistent.nl
Wed Oct 10 18:04:16 CEST 2012
I noticed (to my great dismay!) that ((,) a) doesn't appear to have Foldable or Traversable instance anywhere, even though it is an (almost trivial) instance of both:
instance Foldable ((,) a) where
foldMap f (_, x) = f x
instance Traversable ((,) a) where
traverse f (a, x) = (,) a <$> f x
I guess the most appropriate place for either would be Data.Tuple of Data.Foldable and Data.Traversable respectively.
Kind regards,
Merijn Verstraaten
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