-- @shouldFailWith NoInstanceFound module Main where import Prelude import Control.Monad.Eff (Eff) import Control.Monad.Eff.Console (log) class MyShow a where myShow :: a -> String instance cannotShowFunctions :: Fail "Cannot show functions" => MyShow (a -> b) where myShow _ = "unreachable" main :: Eff _ _ main = log (myShow (_ + 1))