{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FunctionalDependencies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE CPP #-}
module Control.Monad.Gen.Class where
#if MIN_VERSION_mtl(2, 2, 1)
import Control.Monad.Except
#else
import Control.Monad.Trans.Error
#endif
import Control.Monad.Cont
import Control.Monad.List
import Control.Monad.RWS
import Control.Monad.Reader
import Control.Monad.State
import qualified Control.Monad.State.Strict as SS
import Control.Monad.Trans.Identity
import Control.Monad.Trans.Maybe
import Control.Monad.Writer
import qualified Control.Monad.Writer.Strict as SW
class Monad m => MonadGen e m | m -> e where
gen :: m e
instance MonadGen e m => MonadGen e (IdentityT m) where
gen :: IdentityT m e
gen = m e -> IdentityT m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance MonadGen e m => MonadGen e (StateT s m) where
gen :: StateT s m e
gen = m e -> StateT s m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance MonadGen e m => MonadGen e (ReaderT s m) where
gen :: ReaderT s m e
gen = m e -> ReaderT s m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance (MonadGen e m, Monoid s) => MonadGen e (WriterT s m) where
gen :: WriterT s m e
gen = m e -> WriterT s m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance MonadGen e m => MonadGen e (ListT m) where
gen :: ListT m e
gen = m e -> ListT m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance MonadGen e m => MonadGen e (MaybeT m) where
gen :: MaybeT m e
gen = m e -> MaybeT m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance MonadGen e m => MonadGen e (ContT r m) where
gen :: ContT r m e
gen = m e -> ContT r m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance (Monoid w, MonadGen e m) => MonadGen e (RWST r w s m) where
gen :: RWST r w s m e
gen = m e -> RWST r w s m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance MonadGen e m => MonadGen e (SS.StateT s m) where
gen :: StateT s m e
gen = m e -> StateT s m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
instance (Monoid w, MonadGen e m) => MonadGen e (SW.WriterT w m) where
gen :: WriterT w m e
gen = m e -> WriterT w m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
#if MIN_VERSION_mtl(2, 2, 1)
instance (MonadGen e m) => MonadGen e (ExceptT e' m) where
gen :: ExceptT e' m e
gen = m e -> ExceptT e' m e
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift m e
forall e (m :: * -> *). MonadGen e m => m e
gen
#else
instance (MonadGen e m, Error e') => MonadGen e (ErrorT e' m) where
gen = lift gen
#endif