espial/src/Generic.hs
Jon Schoning 2e3e7097e6 init
2019-01-30 20:54:47 -06:00

21 lines
631 B
Haskell

module Generic where
import GHC.Generics
import ClassyPrelude.Yesod
constrName :: (HasConstructor (Rep a), Generic a)=> a -> String
constrName = genericConstrName . from
class HasConstructor (f :: * -> *) where
genericConstrName :: f x -> String
instance HasConstructor f => HasConstructor (D1 c f) where
genericConstrName (M1 x) = genericConstrName x
instance (HasConstructor x, HasConstructor y) => HasConstructor (x :+: y) where
genericConstrName (L1 l) = genericConstrName l
genericConstrName (R1 r) = genericConstrName r
instance Constructor c => HasConstructor (C1 c f) where
genericConstrName x = conName x