monads-tf-0.3.0.1: Monad classes, using type families
Copyright(c) Andy Gill 2001
(c) Oregon Graduate Institute of Science and Technology 2001
LicenseBSD-style (see the file LICENSE)
Maintainerross@soi.city.ac.uk
Stabilityexperimental
Portabilitynon-portable (type families)
Safe HaskellNone
LanguageGHC2021

Control.Monad.State.Strict

Description

Strict state monads.

This module is inspired by the paper /Functional Programming with Overloading and Higher-Order Polymorphism/, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

Synopsis

MonadState class

class Monad m => MonadState (m :: Type -> Type) where Source #

get returns the state from the internals of the monad.

put replaces the state inside the monad.

Associated Types

type StateType (m :: Type -> Type) Source #

Methods

get :: m (StateType m) Source #

put :: StateType m -> m () Source #

Instances

Instances details
MonadState m => MonadState (MaybeT m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (MaybeT m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (MaybeT m) = StateType m

Methods

get :: MaybeT m (StateType (MaybeT m)) Source #

put :: StateType (MaybeT m) -> MaybeT m () Source #

MonadState m => MonadState (ExceptT e m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (ExceptT e m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (ExceptT e m) = StateType m

Methods

get :: ExceptT e m (StateType (ExceptT e m)) Source #

put :: StateType (ExceptT e m) -> ExceptT e m () Source #

MonadState m => MonadState (IdentityT m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (IdentityT m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (IdentityT m) = StateType m

Methods

get :: IdentityT m (StateType (IdentityT m)) Source #

put :: StateType (IdentityT m) -> IdentityT m () Source #

MonadState m => MonadState (ReaderT r m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (ReaderT r m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (ReaderT r m) = StateType m

Methods

get :: ReaderT r m (StateType (ReaderT r m)) Source #

put :: StateType (ReaderT r m) -> ReaderT r m () Source #

Monad m => MonadState (StateT s m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (StateT s m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (StateT s m) = s

Methods

get :: StateT s m (StateType (StateT s m)) Source #

put :: StateType (StateT s m) -> StateT s m () Source #

Monad m => MonadState (StateT s m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (StateT s m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (StateT s m) = s

Methods

get :: StateT s m (StateType (StateT s m)) Source #

put :: StateType (StateT s m) -> StateT s m () Source #

(Monoid w, MonadState m) => MonadState (WriterT w m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (WriterT w m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (WriterT w m) = StateType m

Methods

get :: WriterT w m (StateType (WriterT w m)) Source #

put :: StateType (WriterT w m) -> WriterT w m () Source #

(Monoid w, MonadState m) => MonadState (WriterT w m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (WriterT w m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (WriterT w m) = StateType m

Methods

get :: WriterT w m (StateType (WriterT w m)) Source #

put :: StateType (WriterT w m) -> WriterT w m () Source #

MonadState m => MonadState (ContT r m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (ContT r m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (ContT r m) = StateType m

Methods

get :: ContT r m (StateType (ContT r m)) Source #

put :: StateType (ContT r m) -> ContT r m () Source #

(Monad m, Monoid w) => MonadState (RWST r w s m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (RWST r w s m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (RWST r w s m) = s

Methods

get :: RWST r w s m (StateType (RWST r w s m)) Source #

put :: StateType (RWST r w s m) -> RWST r w s m () Source #

(Monad m, Monoid w) => MonadState (RWST r w s m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (RWST r w s m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (RWST r w s m) = s

Methods

get :: RWST r w s m (StateType (RWST r w s m)) Source #

put :: StateType (RWST r w s m) -> RWST r w s m () Source #

modify :: MonadState m => (StateType m -> StateType m) -> m () Source #

Monadic state transformer.

Maps an old state to a new state inside a state monad. The old state is thrown away.

     Main> :t modify ((+1) :: Int -> Int)
     modify (...) :: (MonadState Int a) => a ()

This says that modify (+1) acts over any Monad that is a member of the MonadState class, with an Int state.

gets :: MonadState m => (StateType m -> a) -> m a Source #

Gets specific component of the state, using a projection function supplied.

The State monad

type State s = StateT s Identity #

runState :: State s a -> s -> (a, s) #

evalState :: State s a -> s -> a #

execState :: State s a -> s -> s #

mapState :: ((a, s) -> (b, s)) -> State s a -> State s b #

withState :: (s -> s) -> State s a -> State s a #

The StateT monad transformer

newtype StateT s (m :: Type -> Type) a #

Constructors

StateT 

Fields

Instances

Instances details
MonadTrans (StateT s) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

lift :: Monad m => m a -> StateT s m a #

MonadFail m => MonadFail (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

fail :: String -> StateT s m a #

MonadFix m => MonadFix (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

mfix :: (a -> StateT s m a) -> StateT s m a #

MonadIO m => MonadIO (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

liftIO :: IO a -> StateT s m a #

Contravariant m => Contravariant (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

contramap :: (a' -> a) -> StateT s m a -> StateT s m a'

(>$) :: b -> StateT s m b -> StateT s m a

(Functor m, MonadPlus m) => Alternative (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

empty :: StateT s m a

(<|>) :: StateT s m a -> StateT s m a -> StateT s m a

some :: StateT s m a -> StateT s m [a]

many :: StateT s m a -> StateT s m [a]

(Functor m, Monad m) => Applicative (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

pure :: a -> StateT s m a

(<*>) :: StateT s m (a -> b) -> StateT s m a -> StateT s m b

liftA2 :: (a -> b -> c) -> StateT s m a -> StateT s m b -> StateT s m c

(*>) :: StateT s m a -> StateT s m b -> StateT s m b

(<*) :: StateT s m a -> StateT s m b -> StateT s m a

Functor m => Functor (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

fmap :: (a -> b) -> StateT s m a -> StateT s m b #

(<$) :: a -> StateT s m b -> StateT s m a #

Monad m => Monad (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

(>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b #

(>>) :: StateT s m a -> StateT s m b -> StateT s m b #

return :: a -> StateT s m a #

MonadPlus m => MonadPlus (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

mzero :: StateT s m a #

mplus :: StateT s m a -> StateT s m a -> StateT s m a #

MonadCont m => MonadCont (StateT s m) Source # 
Instance details

Defined in Control.Monad.Cont.Class

Methods

callCC :: ((a -> StateT s m b) -> StateT s m a) -> StateT s m a Source #

MonadError m => MonadError (StateT s m) Source # 
Instance details

Defined in Control.Monad.Except.Class

Associated Types

type ErrorType (StateT s m) 
Instance details

Defined in Control.Monad.Except.Class

type ErrorType (StateT s m) = ErrorType m

Methods

throwError :: ErrorType (StateT s m) -> StateT s m a Source #

catchError :: StateT s m a -> (ErrorType (StateT s m) -> StateT s m a) -> StateT s m a Source #

MonadReader m => MonadReader (StateT s m) Source # 
Instance details

Defined in Control.Monad.Reader.Class

Associated Types

type EnvType (StateT s m) 
Instance details

Defined in Control.Monad.Reader.Class

type EnvType (StateT s m) = EnvType m

Methods

ask :: StateT s m (EnvType (StateT s m)) Source #

local :: (EnvType (StateT s m) -> EnvType (StateT s m)) -> StateT s m a -> StateT s m a Source #

Monad m => MonadState (StateT s m) Source # 
Instance details

Defined in Control.Monad.State.Class

Associated Types

type StateType (StateT s m) 
Instance details

Defined in Control.Monad.State.Class

type StateType (StateT s m) = s

Methods

get :: StateT s m (StateType (StateT s m)) Source #

put :: StateType (StateT s m) -> StateT s m () Source #

MonadWriter m => MonadWriter (StateT s m) Source # 
Instance details

Defined in Control.Monad.Writer.Class

Associated Types

type WriterType (StateT s m) 
Instance details

Defined in Control.Monad.Writer.Class

Methods

tell :: WriterType (StateT s m) -> StateT s m () Source #

listen :: StateT s m a -> StateT s m (a, WriterType (StateT s m)) Source #

pass :: StateT s m (a, WriterType (StateT s m) -> WriterType (StateT s m)) -> StateT s m a Source #

Generic (StateT s m a) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Associated Types

type Rep (StateT s m a) 
Instance details

Defined in Control.Monad.Trans.State.Strict

type Rep (StateT s m a) = D1 ('MetaData "StateT" "Control.Monad.Trans.State.Strict" "transformers-0.6.1.0-a97a" 'True) (C1 ('MetaCons "StateT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runStateT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (s -> m (a, s)))))

Methods

from :: StateT s m a -> Rep (StateT s m a) x

to :: Rep (StateT s m a) x -> StateT s m a

type ErrorType (StateT s m) Source # 
Instance details

Defined in Control.Monad.Except.Class

type ErrorType (StateT s m) = ErrorType m
type EnvType (StateT s m) Source # 
Instance details

Defined in Control.Monad.Reader.Class

type EnvType (StateT s m) = EnvType m
type StateType (StateT s m) Source # 
Instance details

Defined in Control.Monad.State.Class

type StateType (StateT s m) = s
type WriterType (StateT s m) Source # 
Instance details

Defined in Control.Monad.Writer.Class

type Rep (StateT s m a) 
Instance details

Defined in Control.Monad.Trans.State.Strict

type Rep (StateT s m a) = D1 ('MetaData "StateT" "Control.Monad.Trans.State.Strict" "transformers-0.6.1.0-a97a" 'True) (C1 ('MetaCons "StateT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runStateT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (s -> m (a, s)))))

evalStateT :: Monad m => StateT s m a -> s -> m a #

execStateT :: Monad m => StateT s m a -> s -> m s #

mapStateT :: (m (a, s) -> n (b, s)) -> StateT s m a -> StateT s n b #

withStateT :: forall s (m :: Type -> Type) a. (s -> s) -> StateT s m a -> StateT s m a #

class Applicative m => Monad (m :: Type -> Type) where #

Minimal complete definition

(>>=)

Methods

(>>=) :: m a -> (a -> m b) -> m b #

(>>) :: m a -> m b -> m b #

return :: a -> m a #

Instances

Instances details
Monad Complex 
Instance details

Defined in Data.Complex

Methods

(>>=) :: Complex a -> (a -> Complex b) -> Complex b #

(>>) :: Complex a -> Complex b -> Complex b #

return :: a -> Complex a #

Monad Identity 
Instance details

Defined in Data.Functor.Identity

Methods

(>>=) :: Identity a -> (a -> Identity b) -> Identity b #

(>>) :: Identity a -> Identity b -> Identity b #

return :: a -> Identity a #

Monad First 
Instance details

Defined in Data.Monoid

Methods

(>>=) :: First a -> (a -> First b) -> First b #

(>>) :: First a -> First b -> First b #

return :: a -> First a #

Monad Last 
Instance details

Defined in Data.Monoid

Methods

(>>=) :: Last a -> (a -> Last b) -> Last b #

(>>) :: Last a -> Last b -> Last b #

return :: a -> Last a #

Monad Down 
Instance details

Defined in Data.Ord

Methods

(>>=) :: Down a -> (a -> Down b) -> Down b #

(>>) :: Down a -> Down b -> Down b #

return :: a -> Down a #

Monad First 
Instance details

Defined in Data.Semigroup

Methods

(>>=) :: First a -> (a -> First b) -> First b #

(>>) :: First a -> First b -> First b #

return :: a -> First a #

Monad Last 
Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Last a -> (a -> Last b) -> Last b #

(>>) :: Last a -> Last b -> Last b #

return :: a -> Last a #

Monad Max 
Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Max a -> (a -> Max b) -> Max b #

(>>) :: Max a -> Max b -> Max b #

return :: a -> Max a #

Monad Min 
Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Min a -> (a -> Min b) -> Min b #

(>>) :: Min a -> Min b -> Min b #

return :: a -> Min a #

Monad Dual 
Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Dual a -> (a -> Dual b) -> Dual b #

(>>) :: Dual a -> Dual b -> Dual b #

return :: a -> Dual a #

Monad Product 
Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Product a -> (a -> Product b) -> Product b #

(>>) :: Product a -> Product b -> Product b #

return :: a -> Product a #

Monad Sum 
Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Sum a -> (a -> Sum b) -> Sum b #

(>>) :: Sum a -> Sum b -> Sum b #

return :: a -> Sum a #

Monad NonEmpty 
Instance details

Defined in GHC.Base

Methods

(>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b #

(>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b #

return :: a -> NonEmpty a #

Monad STM 
Instance details

Defined in GHC.Conc.Sync

Methods

(>>=) :: STM a -> (a -> STM b) -> STM b #

(>>) :: STM a -> STM b -> STM b #

return :: a -> STM a #

Monad NoIO 
Instance details

Defined in GHC.GHCi

Methods

(>>=) :: NoIO a -> (a -> NoIO b) -> NoIO b #

(>>) :: NoIO a -> NoIO b -> NoIO b #

return :: a -> NoIO a #

Monad Par1 
Instance details

Defined in GHC.Generics

Methods

(>>=) :: Par1 a -> (a -> Par1 b) -> Par1 b #

(>>) :: Par1 a -> Par1 b -> Par1 b #

return :: a -> Par1 a #

Monad P 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

(>>=) :: P a -> (a -> P b) -> P b #

(>>) :: P a -> P b -> P b #

return :: a -> P a #

Monad ReadP 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

(>>=) :: ReadP a -> (a -> ReadP b) -> ReadP b #

(>>) :: ReadP a -> ReadP b -> ReadP b #

return :: a -> ReadP a #

Monad ReadPrec 
Instance details

Defined in Text.ParserCombinators.ReadPrec

Methods

(>>=) :: ReadPrec a -> (a -> ReadPrec b) -> ReadPrec b #

(>>) :: ReadPrec a -> ReadPrec b -> ReadPrec b #

return :: a -> ReadPrec a #

Monad IO 
Instance details

Defined in GHC.Base

Methods

(>>=) :: IO a -> (a -> IO b) -> IO b #

(>>) :: IO a -> IO b -> IO b #

return :: a -> IO a #

Monad Maybe 
Instance details

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b #

(>>) :: Maybe a -> Maybe b -> Maybe b #

return :: a -> Maybe a #

Monad Solo 
Instance details

Defined in GHC.Base

Methods

(>>=) :: Solo a -> (a -> Solo b) -> Solo b #

(>>) :: Solo a -> Solo b -> Solo b #

return :: a -> Solo a #

Monad [] 
Instance details

Defined in GHC.Base

Methods

(>>=) :: [a] -> (a -> [b]) -> [b] #

(>>) :: [a] -> [b] -> [b] #

return :: a -> [a] #

Monad m => Monad (WrappedMonad m) 
Instance details

Defined in Control.Applicative

Methods

(>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b #

(>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b #

return :: a -> WrappedMonad m a #

ArrowApply a => Monad (ArrowMonad a) 
Instance details

Defined in Control.Arrow

Methods

(>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b #

(>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b #

return :: a0 -> ArrowMonad a a0 #

Monad (Either e) 
Instance details

Defined in Data.Either

Methods

(>>=) :: Either e a -> (a -> Either e b) -> Either e b #

(>>) :: Either e a -> Either e b -> Either e b #

return :: a -> Either e a #

Monad (Proxy :: Type -> Type) 
Instance details

Defined in Data.Proxy

Methods

(>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b #

(>>) :: Proxy a -> Proxy b -> Proxy b #

return :: a -> Proxy a #

Monad (U1 :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

(>>=) :: U1 a -> (a -> U1 b) -> U1 b #

(>>) :: U1 a -> U1 b -> U1 b #

return :: a -> U1 a #

Monad (ST s) 
Instance details

Defined in GHC.ST

Methods

(>>=) :: ST s a -> (a -> ST s b) -> ST s b #

(>>) :: ST s a -> ST s b -> ST s b #

return :: a -> ST s a #

Monad m => Monad (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

(>>=) :: MaybeT m a -> (a -> MaybeT m b) -> MaybeT m b #

(>>) :: MaybeT m a -> MaybeT m b -> MaybeT m b #

return :: a -> MaybeT m a #

Monoid a => Monad ((,) a) 
Instance details

Defined in GHC.Base

Methods

(>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b) #

(>>) :: (a, a0) -> (a, b) -> (a, b) #

return :: a0 -> (a, a0) #

Monad m => Monad (Kleisli m a) 
Instance details

Defined in Control.Arrow

Methods

(>>=) :: Kleisli m a a0 -> (a0 -> Kleisli m a b) -> Kleisli m a b #

(>>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b #

return :: a0 -> Kleisli m a a0 #

Monad f => Monad (Ap f) 
Instance details

Defined in Data.Monoid

Methods

(>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b #

(>>) :: Ap f a -> Ap f b -> Ap f b #

return :: a -> Ap f a #

Monad f => Monad (Alt f) 
Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Alt f a -> (a -> Alt f b) -> Alt f b #

(>>) :: Alt f a -> Alt f b -> Alt f b #

return :: a -> Alt f a #

Monad f => Monad (Rec1 f) 
Instance details

Defined in GHC.Generics

Methods

(>>=) :: Rec1 f a -> (a -> Rec1 f b) -> Rec1 f b #

(>>) :: Rec1 f a -> Rec1 f b -> Rec1 f b #

return :: a -> Rec1 f a #

(Monoid w, Functor m, Monad m) => Monad (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

(>>=) :: AccumT w m a -> (a -> AccumT w m b) -> AccumT w m b #

(>>) :: AccumT w m a -> AccumT w m b -> AccumT w m b #

return :: a -> AccumT w m a #

Monad m => Monad (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

(>>=) :: ExceptT e m a -> (a -> ExceptT e m b) -> ExceptT e m b #

(>>) :: ExceptT e m a -> ExceptT e m b -> ExceptT e m b #

return :: a -> ExceptT e m a #

Monad m => Monad (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

(>>=) :: IdentityT m a -> (a -> IdentityT m b) -> IdentityT m b #

(>>) :: IdentityT m a -> IdentityT m b -> IdentityT m b #

return :: a -> IdentityT m a #

Monad m => Monad (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

(>>=) :: ReaderT r m a -> (a -> ReaderT r m b) -> ReaderT r m b #

(>>) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m b #

return :: a -> ReaderT r m a #

Monad m => Monad (SelectT r m) 
Instance details

Defined in Control.Monad.Trans.Select

Methods

(>>=) :: SelectT r m a -> (a -> SelectT r m b) -> SelectT r m b #

(>>) :: SelectT r m a -> SelectT r m b -> SelectT r m b #

return :: a -> SelectT r m a #

Monad m => Monad (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

(>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b #

(>>) :: StateT s m a -> StateT s m b -> StateT s m b #

return :: a -> StateT s m a #

Monad m => Monad (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

(>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b #

(>>) :: StateT s m a -> StateT s m b -> StateT s m b #

return :: a -> StateT s m a #

Monad m => Monad (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.CPS

Methods

(>>=) :: WriterT w m a -> (a -> WriterT w m b) -> WriterT w m b #

(>>) :: WriterT w m a -> WriterT w m b -> WriterT w m b #

return :: a -> WriterT w m a #

(Monoid w, Monad m) => Monad (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

(>>=) :: WriterT w m a -> (a -> WriterT w m b) -> WriterT w m b #

(>>) :: WriterT w m a -> WriterT w m b -> WriterT w m b #

return :: a -> WriterT w m a #

(Monoid w, Monad m) => Monad (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

(>>=) :: WriterT w m a -> (a -> WriterT w m b) -> WriterT w m b #

(>>) :: WriterT w m a -> WriterT w m b -> WriterT w m b #

return :: a -> WriterT w m a #

Monad m => Monad (Reverse m) 
Instance details

Defined in Data.Functor.Reverse

Methods

(>>=) :: Reverse m a -> (a -> Reverse m b) -> Reverse m b #

(>>) :: Reverse m a -> Reverse m b -> Reverse m b #

return :: a -> Reverse m a #

(Monoid a, Monoid b) => Monad ((,,) a b) 
Instance details

Defined in GHC.Base

Methods

(>>=) :: (a, b, a0) -> (a0 -> (a, b, b0)) -> (a, b, b0) #

(>>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0) #

return :: a0 -> (a, b, a0) #

(Monad f, Monad g) => Monad (Product f g) 
Instance details

Defined in Data.Functor.Product

Methods

(>>=) :: Product f g a -> (a -> Product f g b) -> Product f g b #

(>>) :: Product f g a -> Product f g b -> Product f g b #

return :: a -> Product f g a #

(Monad f, Monad g) => Monad (f :*: g) 
Instance details

Defined in GHC.Generics

Methods

(>>=) :: (f :*: g) a -> (a -> (f :*: g) b) -> (f :*: g) b #

(>>) :: (f :*: g) a -> (f :*: g) b -> (f :*: g) b #

return :: a -> (f :*: g) a #

Monad (ContT r m) 
Instance details

Defined in Control.Monad.Trans.Cont

Methods

(>>=) :: ContT r m a -> (a -> ContT r m b) -> ContT r m b #

(>>) :: ContT r m a -> ContT r m b -> ContT r m b #

return :: a -> ContT r m a #

(Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) 
Instance details

Defined in GHC.Base

Methods

(>>=) :: (a, b, c, a0) -> (a0 -> (a, b, c, b0)) -> (a, b, c, b0) #

(>>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0) #

return :: a0 -> (a, b, c, a0) #

Monad ((->) r) 
Instance details

Defined in GHC.Base

Methods

(>>=) :: (r -> a) -> (a -> r -> b) -> r -> b #

(>>) :: (r -> a) -> (r -> b) -> r -> b #

return :: a -> r -> a #

Monad f => Monad (M1 i c f) 
Instance details

Defined in GHC.Generics

Methods

(>>=) :: M1 i c f a -> (a -> M1 i c f b) -> M1 i c f b #

(>>) :: M1 i c f a -> M1 i c f b -> M1 i c f b #

return :: a -> M1 i c f a #

Monad m => Monad (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.CPS

Methods

(>>=) :: RWST r w s m a -> (a -> RWST r w s m b) -> RWST r w s m b #

(>>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

return :: a -> RWST r w s m a #

(Monoid w, Monad m) => Monad (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

(>>=) :: RWST r w s m a -> (a -> RWST r w s m b) -> RWST r w s m b #

(>>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

return :: a -> RWST r w s m a #

(Monoid w, Monad m) => Monad (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

(>>=) :: RWST r w s m a -> (a -> RWST r w s m b) -> RWST r w s m b #

(>>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

return :: a -> RWST r w s m a #

class Monad m => MonadFail (m :: Type -> Type) where #

Methods

fail :: String -> m a #

Instances

Instances details
MonadFail P 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

fail :: String -> P a #

MonadFail ReadP 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

fail :: String -> ReadP a #

MonadFail ReadPrec 
Instance details

Defined in Text.ParserCombinators.ReadPrec

Methods

fail :: String -> ReadPrec a #

MonadFail IO 
Instance details

Defined in Control.Monad.Fail

Methods

fail :: String -> IO a #

MonadFail Maybe 
Instance details

Defined in Control.Monad.Fail

Methods

fail :: String -> Maybe a #

MonadFail [] 
Instance details

Defined in Control.Monad.Fail

Methods

fail :: String -> [a] #

Monad m => MonadFail (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

fail :: String -> MaybeT m a #

MonadFail f => MonadFail (Ap f) 
Instance details

Defined in Data.Monoid

Methods

fail :: String -> Ap f a #

(Monoid w, MonadFail m) => MonadFail (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

fail :: String -> AccumT w m a #

MonadFail m => MonadFail (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

fail :: String -> ExceptT e m a #

MonadFail m => MonadFail (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

fail :: String -> IdentityT m a #

MonadFail m => MonadFail (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

fail :: String -> ReaderT r m a #

MonadFail m => MonadFail (SelectT r m) 
Instance details

Defined in Control.Monad.Trans.Select

Methods

fail :: String -> SelectT r m a #

MonadFail m => MonadFail (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

fail :: String -> StateT s m a #

MonadFail m => MonadFail (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

fail :: String -> StateT s m a #

MonadFail m => MonadFail (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.CPS

Methods

fail :: String -> WriterT w m a #

(Monoid w, MonadFail m) => MonadFail (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

fail :: String -> WriterT w m a #

(Monoid w, MonadFail m) => MonadFail (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

fail :: String -> WriterT w m a #

MonadFail m => MonadFail (Reverse m) 
Instance details

Defined in Data.Functor.Reverse

Methods

fail :: String -> Reverse m a #

MonadFail m => MonadFail (ContT r m) 
Instance details

Defined in Control.Monad.Trans.Cont

Methods

fail :: String -> ContT r m a #

MonadFail m => MonadFail (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.CPS

Methods

fail :: String -> RWST r w s m a #

(Monoid w, MonadFail m) => MonadFail (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

fail :: String -> RWST r w s m a #

(Monoid w, MonadFail m) => MonadFail (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

fail :: String -> RWST r w s m a #

mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m () #

sequence_ :: (Foldable t, Monad m) => t (m a) -> m () #

mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b) #

sequence :: (Traversable t, Monad m) => t (m a) -> m (t a) #

class Functor (f :: Type -> Type) where #

Minimal complete definition

fmap

Methods

fmap :: (a -> b) -> f a -> f b #

(<$) :: a -> f b -> f a #

Instances

Instances details
Functor ZipList 
Instance details

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> ZipList a -> ZipList b #

(<$) :: a -> ZipList b -> ZipList a #

Functor Handler 
Instance details

Defined in Control.Exception

Methods

fmap :: (a -> b) -> Handler a -> Handler b #

(<$) :: a -> Handler b -> Handler a #

Functor Complex 
Instance details

Defined in Data.Complex

Methods

fmap :: (a -> b) -> Complex a -> Complex b #

(<$) :: a -> Complex b -> Complex a #

Functor Identity 
Instance details

Defined in Data.Functor.Identity

Methods

fmap :: (a -> b) -> Identity a -> Identity b #

(<$) :: a -> Identity b -> Identity a #

Functor First 
Instance details

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> First a -> First b #

(<$) :: a -> First b -> First a #

Functor Last 
Instance details

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> Last a -> Last b #

(<$) :: a -> Last b -> Last a #

Functor Down 
Instance details

Defined in Data.Ord

Methods

fmap :: (a -> b) -> Down a -> Down b #

(<$) :: a -> Down b -> Down a #

Functor First 
Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> First a -> First b #

(<$) :: a -> First b -> First a #

Functor Last 
Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Last a -> Last b #

(<$) :: a -> Last b -> Last a #

Functor Max 
Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Max a -> Max b #

(<$) :: a -> Max b -> Max a #

Functor Min 
Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Min a -> Min b #

(<$) :: a -> Min b -> Min a #

Functor Dual 
Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Dual a -> Dual b #

(<$) :: a -> Dual b -> Dual a #

Functor Product 
Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Product a -> Product b #

(<$) :: a -> Product b -> Product a #

Functor Sum 
Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Sum a -> Sum b #

(<$) :: a -> Sum b -> Sum a #

Functor NonEmpty 
Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> NonEmpty a -> NonEmpty b #

(<$) :: a -> NonEmpty b -> NonEmpty a #

Functor STM 
Instance details

Defined in GHC.Conc.Sync

Methods

fmap :: (a -> b) -> STM a -> STM b #

(<$) :: a -> STM b -> STM a #

Functor NoIO 
Instance details

Defined in GHC.GHCi

Methods

fmap :: (a -> b) -> NoIO a -> NoIO b #

(<$) :: a -> NoIO b -> NoIO a #

Functor Par1 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Par1 a -> Par1 b #

(<$) :: a -> Par1 b -> Par1 a #

Functor ArgDescr 
Instance details

Defined in System.Console.GetOpt

Methods

fmap :: (a -> b) -> ArgDescr a -> ArgDescr b #

(<$) :: a -> ArgDescr b -> ArgDescr a #

Functor ArgOrder 
Instance details

Defined in System.Console.GetOpt

Methods

fmap :: (a -> b) -> ArgOrder a -> ArgOrder b #

(<$) :: a -> ArgOrder b -> ArgOrder a #

Functor OptDescr 
Instance details

Defined in System.Console.GetOpt

Methods

fmap :: (a -> b) -> OptDescr a -> OptDescr b #

(<$) :: a -> OptDescr b -> OptDescr a #

Functor P 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

fmap :: (a -> b) -> P a -> P b #

(<$) :: a -> P b -> P a #

Functor ReadP 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

fmap :: (a -> b) -> ReadP a -> ReadP b #

(<$) :: a -> ReadP b -> ReadP a #

Functor ReadPrec 
Instance details

Defined in Text.ParserCombinators.ReadPrec

Methods

fmap :: (a -> b) -> ReadPrec a -> ReadPrec b #

(<$) :: a -> ReadPrec b -> ReadPrec a #

Functor IO 
Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b #

(<$) :: a -> IO b -> IO a #

Functor Maybe 
Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b #

(<$) :: a -> Maybe b -> Maybe a #

Functor Solo 
Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Solo a -> Solo b #

(<$) :: a -> Solo b -> Solo a #

Functor [] 
Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> [a] -> [b] #

(<$) :: a -> [b] -> [a] #

Monad m => Functor (WrappedMonad m) 
Instance details

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b #

(<$) :: a -> WrappedMonad m b -> WrappedMonad m a #

Arrow a => Functor (ArrowMonad a) 
Instance details

Defined in Control.Arrow

Methods

fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b #

(<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0 #

Functor (Either a) 
Instance details

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b #

(<$) :: a0 -> Either a b -> Either a a0 #

Functor (Proxy :: Type -> Type) 
Instance details

Defined in Data.Proxy

Methods

fmap :: (a -> b) -> Proxy a -> Proxy b #

(<$) :: a -> Proxy b -> Proxy a #

Functor (Arg a) 
Instance details

Defined in Data.Semigroup

Methods

fmap :: (a0 -> b) -> Arg a a0 -> Arg a b #

(<$) :: a0 -> Arg a b -> Arg a a0 #

Functor (Array i) 
Instance details

Defined in GHC.Arr

Methods

fmap :: (a -> b) -> Array i a -> Array i b #

(<$) :: a -> Array i b -> Array i a #

Functor (U1 :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> U1 a -> U1 b #

(<$) :: a -> U1 b -> U1 a #

Functor (V1 :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> V1 a -> V1 b #

(<$) :: a -> V1 b -> V1 a #

Functor (ST s) 
Instance details

Defined in GHC.ST

Methods

fmap :: (a -> b) -> ST s a -> ST s b #

(<$) :: a -> ST s b -> ST s a #

Functor f => Functor (Lift f) 
Instance details

Defined in Control.Applicative.Lift

Methods

fmap :: (a -> b) -> Lift f a -> Lift f b #

(<$) :: a -> Lift f b -> Lift f a #

Functor m => Functor (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

fmap :: (a -> b) -> MaybeT m a -> MaybeT m b #

(<$) :: a -> MaybeT m b -> MaybeT m a #

Functor ((,) a) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b) -> (a, a0) -> (a, b) #

(<$) :: a0 -> (a, b) -> (a, a0) #

Arrow a => Functor (WrappedArrow a b) 
Instance details

Defined in Control.Applicative

Methods

fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 #

(<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 #

Functor m => Functor (Kleisli m a) 
Instance details

Defined in Control.Arrow

Methods

fmap :: (a0 -> b) -> Kleisli m a a0 -> Kleisli m a b #

(<$) :: a0 -> Kleisli m a b -> Kleisli m a a0 #

Functor (Const m :: Type -> Type) 
Instance details

Defined in Data.Functor.Const

Methods

fmap :: (a -> b) -> Const m a -> Const m b #

(<$) :: a -> Const m b -> Const m a #

Functor f => Functor (Ap f) 
Instance details

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> Ap f a -> Ap f b #

(<$) :: a -> Ap f b -> Ap f a #

Functor f => Functor (Alt f) 
Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Alt f a -> Alt f b #

(<$) :: a -> Alt f b -> Alt f a #

(Generic1 f, Functor (Rep1 f)) => Functor (Generically1 f) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Generically1 f a -> Generically1 f b #

(<$) :: a -> Generically1 f b -> Generically1 f a #

Functor f => Functor (Rec1 f) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Rec1 f a -> Rec1 f b #

(<$) :: a -> Rec1 f b -> Rec1 f a #

Functor (URec (Ptr ()) :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec (Ptr ()) a -> URec (Ptr ()) b #

(<$) :: a -> URec (Ptr ()) b -> URec (Ptr ()) a #

Functor (URec Char :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Char a -> URec Char b #

(<$) :: a -> URec Char b -> URec Char a #

Functor (URec Double :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Double a -> URec Double b #

(<$) :: a -> URec Double b -> URec Double a #

Functor (URec Float :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Float a -> URec Float b #

(<$) :: a -> URec Float b -> URec Float a #

Functor (URec Int :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Int a -> URec Int b #

(<$) :: a -> URec Int b -> URec Int a #

Functor (URec Word :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Word a -> URec Word b #

(<$) :: a -> URec Word b -> URec Word a #

Functor f => Functor (Backwards f) 
Instance details

Defined in Control.Applicative.Backwards

Methods

fmap :: (a -> b) -> Backwards f a -> Backwards f b #

(<$) :: a -> Backwards f b -> Backwards f a #

Functor m => Functor (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

fmap :: (a -> b) -> AccumT w m a -> AccumT w m b #

(<$) :: a -> AccumT w m b -> AccumT w m a #

Functor m => Functor (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

fmap :: (a -> b) -> ExceptT e m a -> ExceptT e m b #

(<$) :: a -> ExceptT e m b -> ExceptT e m a #

Functor m => Functor (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

fmap :: (a -> b) -> IdentityT m a -> IdentityT m b #

(<$) :: a -> IdentityT m b -> IdentityT m a #

Functor m => Functor (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

fmap :: (a -> b) -> ReaderT r m a -> ReaderT r m b #

(<$) :: a -> ReaderT r m b -> ReaderT r m a #

Functor m => Functor (SelectT r m) 
Instance details

Defined in Control.Monad.Trans.Select

Methods

fmap :: (a -> b) -> SelectT r m a -> SelectT r m b #

(<$) :: a -> SelectT r m b -> SelectT r m a #

Functor m => Functor (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

fmap :: (a -> b) -> StateT s m a -> StateT s m b #

(<$) :: a -> StateT s m b -> StateT s m a #

Functor m => Functor (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

fmap :: (a -> b) -> StateT s m a -> StateT s m b #

(<$) :: a -> StateT s m b -> StateT s m a #

Functor m => Functor (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.CPS

Methods

fmap :: (a -> b) -> WriterT w m a -> WriterT w m b #

(<$) :: a -> WriterT w m b -> WriterT w m a #

Functor m => Functor (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

fmap :: (a -> b) -> WriterT w m a -> WriterT w m b #

(<$) :: a -> WriterT w m b -> WriterT w m a #

Functor m => Functor (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

fmap :: (a -> b) -> WriterT w m a -> WriterT w m b #

(<$) :: a -> WriterT w m b -> WriterT w m a #

Functor (Constant a :: Type -> Type) 
Instance details

Defined in Data.Functor.Constant

Methods

fmap :: (a0 -> b) -> Constant a a0 -> Constant a b #

(<$) :: a0 -> Constant a b -> Constant a a0 #

Functor f => Functor (Reverse f) 
Instance details

Defined in Data.Functor.Reverse

Methods

fmap :: (a -> b) -> Reverse f a -> Reverse f b #

(<$) :: a -> Reverse f b -> Reverse f a #

Functor ((,,) a b) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, a0) -> (a, b, b0) #

(<$) :: a0 -> (a, b, b0) -> (a, b, a0) #

(Functor f, Functor g) => Functor (Product f g) 
Instance details

Defined in Data.Functor.Product

Methods

fmap :: (a -> b) -> Product f g a -> Product f g b #

(<$) :: a -> Product f g b -> Product f g a #

(Functor f, Functor g) => Functor (Sum f g) 
Instance details

Defined in Data.Functor.Sum

Methods

fmap :: (a -> b) -> Sum f g a -> Sum f g b #

(<$) :: a -> Sum f g b -> Sum f g a #

(Functor f, Functor g) => Functor (f :*: g) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :*: g) a -> (f :*: g) b #

(<$) :: a -> (f :*: g) b -> (f :*: g) a #

(Functor f, Functor g) => Functor (f :+: g) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :+: g) a -> (f :+: g) b #

(<$) :: a -> (f :+: g) b -> (f :+: g) a #

Functor (K1 i c :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> K1 i c a -> K1 i c b #

(<$) :: a -> K1 i c b -> K1 i c a #

Functor (ContT r m) 
Instance details

Defined in Control.Monad.Trans.Cont

Methods

fmap :: (a -> b) -> ContT r m a -> ContT r m b #

(<$) :: a -> ContT r m b -> ContT r m a #

Functor ((,,,) a b c) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0) #

(<$) :: a0 -> (a, b, c, b0) -> (a, b, c, a0) #

Functor ((->) r) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> (r -> a) -> r -> b #

(<$) :: a -> (r -> b) -> r -> a #

(Functor f, Functor g) => Functor (Compose f g) 
Instance details

Defined in Data.Functor.Compose

Methods

fmap :: (a -> b) -> Compose f g a -> Compose f g b #

(<$) :: a -> Compose f g b -> Compose f g a #

(Functor f, Functor g) => Functor (f :.: g) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :.: g) a -> (f :.: g) b #

(<$) :: a -> (f :.: g) b -> (f :.: g) a #

Functor f => Functor (M1 i c f) 
Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> M1 i c f a -> M1 i c f b #

(<$) :: a -> M1 i c f b -> M1 i c f a #

Functor m => Functor (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.CPS

Methods

fmap :: (a -> b) -> RWST r w s m a -> RWST r w s m b #

(<$) :: a -> RWST r w s m b -> RWST r w s m a #

Functor m => Functor (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

fmap :: (a -> b) -> RWST r w s m a -> RWST r w s m b #

(<$) :: a -> RWST r w s m b -> RWST r w s m a #

Functor m => Functor (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

fmap :: (a -> b) -> RWST r w s m a -> RWST r w s m b #

(<$) :: a -> RWST r w s m b -> RWST r w s m a #

Functor ((,,,,) a b c d) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, d, a0) -> (a, b, c, d, b0) #

(<$) :: a0 -> (a, b, c, d, b0) -> (a, b, c, d, a0) #

Functor ((,,,,,) a b c d e) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, d, e, a0) -> (a, b, c, d, e, b0) #

(<$) :: a0 -> (a, b, c, d, e, b0) -> (a, b, c, d, e, a0) #

Functor ((,,,,,,) a b c d e f) 
Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, d, e, f, a0) -> (a, b, c, d, e, f, b0) #

(<$) :: a0 -> (a, b, c, d, e, f, b0) -> (a, b, c, d, e, f, a0) #

(=<<) :: Monad m => (a -> m b) -> m a -> m b #

join :: Monad m => m (m a) -> m a #

class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where #

Minimal complete definition

Nothing

Methods

mzero :: m a #

mplus :: m a -> m a -> m a #

Instances

Instances details
MonadPlus STM 
Instance details

Defined in GHC.Conc.Sync

Methods

mzero :: STM a #

mplus :: STM a -> STM a -> STM a #

MonadPlus P 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

mzero :: P a #

mplus :: P a -> P a -> P a #

MonadPlus ReadP 
Instance details

Defined in Text.ParserCombinators.ReadP

Methods

mzero :: ReadP a #

mplus :: ReadP a -> ReadP a -> ReadP a #

MonadPlus ReadPrec 
Instance details

Defined in Text.ParserCombinators.ReadPrec

Methods

mzero :: ReadPrec a #

mplus :: ReadPrec a -> ReadPrec a -> ReadPrec a #

MonadPlus IO 
Instance details

Defined in GHC.Base

Methods

mzero :: IO a #

mplus :: IO a -> IO a -> IO a #

MonadPlus Maybe 
Instance details

Defined in GHC.Base

Methods

mzero :: Maybe a #

mplus :: Maybe a -> Maybe a -> Maybe a #

MonadPlus [] 
Instance details

Defined in GHC.Base

Methods

mzero :: [a] #

mplus :: [a] -> [a] -> [a] #

(ArrowApply a, ArrowPlus a) => MonadPlus (ArrowMonad a) 
Instance details

Defined in Control.Arrow

Methods

mzero :: ArrowMonad a a0 #

mplus :: ArrowMonad a a0 -> ArrowMonad a a0 -> ArrowMonad a a0 #

MonadPlus (Proxy :: Type -> Type) 
Instance details

Defined in Data.Proxy

Methods

mzero :: Proxy a #

mplus :: Proxy a -> Proxy a -> Proxy a #

MonadPlus (U1 :: Type -> Type) 
Instance details

Defined in GHC.Generics

Methods

mzero :: U1 a #

mplus :: U1 a -> U1 a -> U1 a #

Monad m => MonadPlus (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

mzero :: MaybeT m a #

mplus :: MaybeT m a -> MaybeT m a -> MaybeT m a #

MonadPlus m => MonadPlus (Kleisli m a) 
Instance details

Defined in Control.Arrow

Methods

mzero :: Kleisli m a a0 #

mplus :: Kleisli m a a0 -> Kleisli m a a0 -> Kleisli m a a0 #

MonadPlus f => MonadPlus (Ap f) 
Instance details

Defined in Data.Monoid

Methods

mzero :: Ap f a #

mplus :: Ap f a -> Ap f a -> Ap f a #

MonadPlus f => MonadPlus (Alt f) 
Instance details

Defined in Data.Semigroup.Internal

Methods

mzero :: Alt f a #

mplus :: Alt f a -> Alt f a -> Alt f a #

MonadPlus f => MonadPlus (Rec1 f) 
Instance details

Defined in GHC.Generics

Methods

mzero :: Rec1 f a #

mplus :: Rec1 f a -> Rec1 f a -> Rec1 f a #

(Monoid w, Functor m, MonadPlus m) => MonadPlus (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

mzero :: AccumT w m a #

mplus :: AccumT w m a -> AccumT w m a -> AccumT w m a #

(Monad m, Monoid e) => MonadPlus (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

mzero :: ExceptT e m a #

mplus :: ExceptT e m a -> ExceptT e m a -> ExceptT e m a #

MonadPlus m => MonadPlus (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

mzero :: IdentityT m a #

mplus :: IdentityT m a -> IdentityT m a -> IdentityT m a #

MonadPlus m => MonadPlus (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

mzero :: ReaderT r m a #

mplus :: ReaderT r m a -> ReaderT r m a -> ReaderT r m a #

MonadPlus m => MonadPlus (SelectT r m) 
Instance details

Defined in Control.Monad.Trans.Select

Methods

mzero :: SelectT r m a #

mplus :: SelectT r m a -> SelectT r m a -> SelectT r m a #

MonadPlus m => MonadPlus (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

mzero :: StateT s m a #

mplus :: StateT s m a -> StateT s m a -> StateT s m a #

MonadPlus m => MonadPlus (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

mzero :: StateT s m a #

mplus :: StateT s m a -> StateT s m a -> StateT s m a #

(Functor m, MonadPlus m) => MonadPlus (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.CPS

Methods

mzero :: WriterT w m a #

mplus :: WriterT w m a -> WriterT w m a -> WriterT w m a #

(Monoid w, MonadPlus m) => MonadPlus (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

mzero :: WriterT w m a #

mplus :: WriterT w m a -> WriterT w m a -> WriterT w m a #

(Monoid w, MonadPlus m) => MonadPlus (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

mzero :: WriterT w m a #

mplus :: WriterT w m a -> WriterT w m a -> WriterT w m a #

MonadPlus m => MonadPlus (Reverse m) 
Instance details

Defined in Data.Functor.Reverse

Methods

mzero :: Reverse m a #

mplus :: Reverse m a -> Reverse m a -> Reverse m a #

(MonadPlus f, MonadPlus g) => MonadPlus (Product f g) 
Instance details

Defined in Data.Functor.Product

Methods

mzero :: Product f g a #

mplus :: Product f g a -> Product f g a -> Product f g a #

(MonadPlus f, MonadPlus g) => MonadPlus (f :*: g) 
Instance details

Defined in GHC.Generics

Methods

mzero :: (f :*: g) a #

mplus :: (f :*: g) a -> (f :*: g) a -> (f :*: g) a #

MonadPlus f => MonadPlus (M1 i c f) 
Instance details

Defined in GHC.Generics

Methods

mzero :: M1 i c f a #

mplus :: M1 i c f a -> M1 i c f a -> M1 i c f a #

(Functor m, MonadPlus m) => MonadPlus (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.CPS

Methods

mzero :: RWST r w s m a #

mplus :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a #

(Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

mzero :: RWST r w s m a #

mplus :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a #

(Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

mzero :: RWST r w s m a #

mplus :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a #

ap :: Monad m => m (a -> b) -> m a -> m b #

liftM :: Monad m => (a1 -> r) -> m a1 -> m r #

liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r #

liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r #

liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r #

liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r #

when :: Applicative f => Bool -> f () -> f () #

forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m () #

msum :: (Foldable t, MonadPlus m) => t (m a) -> m a #

void :: Functor f => f a -> f () #

forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b) #

(<$!>) :: Monad m => (a -> b) -> m a -> m b #

(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c #

(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c #

foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #

foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m () #

replicateM :: Applicative m => Int -> m a -> m [a] #

replicateM_ :: Applicative m => Int -> m a -> m () #

unless :: Applicative f => Bool -> f () -> f () #

filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a] #

forever :: Applicative f => f a -> f b #

mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c]) #

mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a #

zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c] #

zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m () #

guard :: Alternative f => Bool -> f () #

class Monad m => MonadFix (m :: Type -> Type) where #

Methods

mfix :: (a -> m a) -> m a #

Instances

Instances details
MonadFix Complex 
Instance details

Defined in Data.Complex

Methods

mfix :: (a -> Complex a) -> Complex a #

MonadFix Identity 
Instance details

Defined in Data.Functor.Identity

Methods

mfix :: (a -> Identity a) -> Identity a #

MonadFix First 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> First a) -> First a #

MonadFix Last 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Last a) -> Last a #

MonadFix Down 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Down a) -> Down a #

MonadFix First 
Instance details

Defined in Data.Semigroup

Methods

mfix :: (a -> First a) -> First a #

MonadFix Last 
Instance details

Defined in Data.Semigroup

Methods

mfix :: (a -> Last a) -> Last a #

MonadFix Max 
Instance details

Defined in Data.Semigroup

Methods

mfix :: (a -> Max a) -> Max a #

MonadFix Min 
Instance details

Defined in Data.Semigroup

Methods

mfix :: (a -> Min a) -> Min a #

MonadFix Dual 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Dual a) -> Dual a #

MonadFix Product 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Product a) -> Product a #

MonadFix Sum 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Sum a) -> Sum a #

MonadFix NonEmpty 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> NonEmpty a) -> NonEmpty a #

MonadFix Par1 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Par1 a) -> Par1 a #

MonadFix IO 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> IO a) -> IO a #

MonadFix Maybe 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Maybe a) -> Maybe a #

MonadFix Solo 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Solo a) -> Solo a #

MonadFix [] 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> [a]) -> [a] #

MonadFix (Either e) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Either e a) -> Either e a #

MonadFix (ST s) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> ST s a) -> ST s a #

MonadFix m => MonadFix (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

mfix :: (a -> MaybeT m a) -> MaybeT m a #

MonadFix f => MonadFix (Ap f) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Ap f a) -> Ap f a #

MonadFix f => MonadFix (Alt f) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Alt f a) -> Alt f a #

MonadFix f => MonadFix (Rec1 f) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Rec1 f a) -> Rec1 f a #

(Monoid w, Functor m, MonadFix m) => MonadFix (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

mfix :: (a -> AccumT w m a) -> AccumT w m a #

MonadFix m => MonadFix (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

mfix :: (a -> ExceptT e m a) -> ExceptT e m a #

MonadFix m => MonadFix (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

mfix :: (a -> IdentityT m a) -> IdentityT m a #

MonadFix m => MonadFix (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

mfix :: (a -> ReaderT r m a) -> ReaderT r m a #

MonadFix m => MonadFix (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

mfix :: (a -> StateT s m a) -> StateT s m a #

MonadFix m => MonadFix (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

mfix :: (a -> StateT s m a) -> StateT s m a #

MonadFix m => MonadFix (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.CPS

Methods

mfix :: (a -> WriterT w m a) -> WriterT w m a #

(Monoid w, MonadFix m) => MonadFix (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

mfix :: (a -> WriterT w m a) -> WriterT w m a #

(Monoid w, MonadFix m) => MonadFix (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

mfix :: (a -> WriterT w m a) -> WriterT w m a #

(MonadFix f, MonadFix g) => MonadFix (Product f g) 
Instance details

Defined in Data.Functor.Product

Methods

mfix :: (a -> Product f g a) -> Product f g a #

(MonadFix f, MonadFix g) => MonadFix (f :*: g) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> (f :*: g) a) -> (f :*: g) a #

MonadFix ((->) r) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> r -> a) -> r -> a #

MonadFix f => MonadFix (M1 i c f) 
Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> M1 i c f a) -> M1 i c f a #

MonadFix m => MonadFix (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.CPS

Methods

mfix :: (a -> RWST r w s m a) -> RWST r w s m a #

(Monoid w, MonadFix m) => MonadFix (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

mfix :: (a -> RWST r w s m a) -> RWST r w s m a #

(Monoid w, MonadFix m) => MonadFix (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

mfix :: (a -> RWST r w s m a) -> RWST r w s m a #

fix :: (a -> a) -> a #

Examples

A function to increment a counter. Taken from the paper Generalising Monads to Arrows, John Hughes (http://www.math.chalmers.se/~rjmh/), November 1998:

tick :: State Int Int
tick = do n <- get
          put (n+1)
          return n

Add one to the given number using the state monad:

plusOne :: Int -> Int
plusOne n = execState tick n

A contrived addition example. Works only with positive numbers:

plus :: Int -> Int -> Int
plus n x = execState (sequence $ replicate n tick) x

An example from The Craft of Functional Programming, Simon Thompson (http://www.cs.kent.ac.uk/people/staff/sjt/), Addison-Wesley 1999: "Given an arbitrary tree, transform it to a tree of integers in which the original elements are replaced by natural numbers, starting from 0. The same element has to be replaced by the same number at every occurrence, and when we meet an as-yet-unvisited element we have to find a 'new' number to match it with:"

data Tree a = Nil | Node a (Tree a) (Tree a) deriving (Show, Eq)
type Table a = [a]
numberTree :: Eq a => Tree a -> State (Table a) (Tree Int)
numberTree Nil = return Nil
numberTree (Node x t1 t2)
       =  do num <- numberNode x
             nt1 <- numberTree t1
             nt2 <- numberTree t2
             return (Node num nt1 nt2)
    where
    numberNode :: Eq a => a -> State (Table a) Int
    numberNode x
       = do table <- get
            (newTable, newPos) <- return (nNode x table)
            put newTable
            return newPos
    nNode::  (Eq a) => a -> Table a -> (Table a, Int)
    nNode x table
       = case (findIndexInList (== x) table) of
         Nothing -> (table ++ [x], length table)
         Just i  -> (table, i)
    findIndexInList :: (a -> Bool) -> [a] -> Maybe Int
    findIndexInList = findIndexInListHelp 0
    findIndexInListHelp _ _ [] = Nothing
    findIndexInListHelp count f (h:t)
       = if (f h)
         then Just count
         else findIndexInListHelp (count+1) f t

numTree applies numberTree with an initial state:

numTree :: (Eq a) => Tree a -> Tree Int
numTree t = evalState (numberTree t) []
testTree = Node "Zero" (Node "One" (Node "Two" Nil Nil) (Node "One" (Node "Zero" Nil Nil) Nil)) Nil
numTree testTree => Node 0 (Node 1 (Node 2 Nil Nil) (Node 1 (Node 0 Nil Nil) Nil)) Nil

sumTree is a little helper function that does not use the State monad:

sumTree :: (Num a) => Tree a -> a
sumTree Nil = 0
sumTree (Node e t1 t2) = e + (sumTree t1) + (sumTree t2)