package ReaderModule(ReaderModule, ask, runR) where

data ReaderModule r i = R (r -> Module i)

runR :: ReaderModule r i -> r -> Module i
runR (R _x) = _x

ask :: ReaderModule r r
ask = R (\_r -> return _r)

instance Monad (ReaderModule r) where
  return _i = R (const $ return _i)
  bind _x _f = R (\_r -> do let _n = primGetParamName _f
                            -- messageM $ primGetNameString _n
                            _x' <- runR (setStateName _n _x) _r
                            runR (_f _x') _r
                 )

instance MonadFix (ReaderModule r) where
  mfix :: (i -> ReaderModule r i) -> ReaderModule r i
  mfix _f = R (\_r -> let _f' :: i -> Module i
                          _f' _i = runR (_f _i) _r
                      in mfix _f'
              )

instance (IsModule (ReaderModule r) Id__) where
  liftModule _m = R (const _m)
  liftModuleOp _f _x = R (\_r -> _f (runR _x _r))