gistfile1.hs

insertPerson :: MonadState MyDb m => Person -> m (Fact Person)
insertPerson = insertRecord personRel

--fillit :: MonadState MyDb m => m ()
fillit = do 
  a <- insertPerson (Person "john")
  b <- insertPerson (Person "paul")
  return ()

-- if i leave the type declaraion of fillit commented, i get this error :

    No instance for (MonadState MyDb m0)
      arising from a use of `insertPerson'
    Possible fix: add an instance declaration for (MonadState MyDb m0)
    In a stmt of a 'do' block: a <- insertPerson (Person "john")