yesod-dsl-0.1.1.3: codegen/enum.cg

data ~{enumName e} = ~{intercalate " | " (enumValues e)} deriving (Show, Read, Eq)
derivePersistField "~{enumName e}"

instance A.FromJSON ~{enumName e} where
    parseJSON = A.withText "~{enumName e}" (\v -> case v of
~{parseJSONs}        _ -> mzero)

instance A.ToJSON ~{enumName e} where
~{toJSONs}

instance PathPiece ~{enumName e} where
~{fromPathPieces}
    fromPathPiece _ = Nothing
~{toPathPieces}