+1
I would just suggest calling the exported function `genericRnf`.
Cheers,
Pedro
On Fri, Sep 21, 2012 at 10:21 AM, Herbert Valerio Riedel
Hello Simon (et al.),
Some time ago, the `generic-deepseq` package was announced to the haskell-cafe list, and some discussion took place[1], and the suggestion came up that it might useful to be included to `deepseq` somehow.
IMHO, a least introduing way (which I've been using myself) would be to add something along the code below to the `Control.DeepSeq` module (only `genericsRnf` shall be exported, thus avoiding a PVP-major-bump):
-- | Generics-based 'rnf' implementation genericsRnf :: (Generic a, GNFData (Rep a)) => a -> () genericsRnf = grnf_ . from {-# INLINE genericRnf #-}
-- | Hidden type-class, /not/ exported class GNFData f where grnf_ :: f a -> ()
instance GNFData U1 where grnf_ !U1 = () {-# INLINE grnf_ #-}
instance NFData a => GNFData (K1 i a) where grnf_ = rnf . unK1 {-# INLINE grnf_ #-}
instance GNFData a => GNFData (M1 i c a) where grnf_ = grnf_ . unM1 {-# INLINE grnf_ #-}
instance (GNFData a, GNFData b) => GNFData (a :*: b) where grnf_ (x :*: y) = grnf_ x `seq` grnf_ y {-# INLINE grnf_ #-}
instance (GNFData a, GNFData b) => GNFData (a :+: b) where grnf_ (L1 x) = grnf_ x grnf_ (R1 x) = grnf_ x {-# INLINE grnf_ #-}
this way, the client code can then chose to use a Generics-derived `rnf` implementation expliclity by simply declaring:
instance NFData FooBar where rnf = genericsRnf
...does this sound sensible?
cheers, hvr
[1]: http://www.haskell.org/pipermail/haskell-cafe/2012-February/099551.html
--
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries