Control.DeepSeq.Bounded.Generics.GNFDataN

Support for generic deriving (via Generics.SOP) of NFDataN instances.

NFDataN does not have any superclasses.

It is also possible to derive instances using Generics, which avoids SOP and TH, but if you plan to use NFDataP then SOP is required. (SOP can be used without TH if necessary; the interested reader is referred to SOP documentation.)

This metaboilerplate is standard for using the generic deriving facilities of GHC.Generics and Generics.SOP. Consider seqaid for a turnkey solution.

{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE DeriveGeneric #-}

import Generics.SOP.TH
import Control.DeepSeq.Bounded ( NFDataN(..), grnfn )
import GHC.Generics ( Generic )

import Control.DeepSeq.Bounded ( forcen )

data TA = A1 TB TA | A2  deriving ( Generic )
instance NFDataN TA where rnfn = grnfn

data TB = B1 Int | B2 TA  deriving ( Generic )
instance NFDataN TB where rnfn = grnfn

deriveGeneric ''TA
deriveGeneric ''TB

main = return $! forcen 3 (A1 (B2 undefined) A2)

Documentation

grnfn :: (Generic a, All2 NFDataN (Code a)) => Int -> a -> ()