{-# OPTIONS_GHC -fno-warn-missing-signatures #-} module TypeErrors where -- $setup -- >>> default () -- >>> :set -package polysemy-plugin -- ... -- >>> :set -fplugin=Polysemy.Plugin -- >>> :m +Polysemy -- >>> :m +Polysemy.State -- >>> :m +Data.Maybe -------------------------------------------------------------------------------- -- | -- >>> :{ -- existsKV :: Member (State (Maybe Int)) r => Sem r Bool -- existsKV = isJust get -- :} -- ... -- ... Couldn't match expected type ...Sem r Bool... with actual type ...Bool... -- ... -- ... Couldn't match expected type ...Maybe a0... -- ... with actual type ...Sem r0 a1... -- ... missingFmap = ()