System.Console.Haskeline.Internal · haskeline-0.8.5.0

valueasks :: MonadReader r m => (r -> a) -> m a

#

valueevalStateT' :: Monad m => s -> StateT s m a -> m a

#

valuegets :: MonadState s m => (s -> a) -> m a

#

valuemodify :: MonadState s m => (s -> s) -> m ()

#

valueorElse :: Monad m => MaybeT m a -> m a -> m a

#

valuerunReaderT' :: r -> ReaderT r m a -> m a

#

valueupdate :: MonadState s m => (s -> (a, s)) -> m a

#

valuemapReaderT :: (m a -> n b) -> ReaderT r m a -> ReaderT r n b

#

Transform the computation inside a ReaderT.

runReaderT (mapReaderT f m) = f . runReaderT m

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

#

Map both the return value and final state of a computation using the given function.

runStateT (mapStateT f m) = f . runStateT m

classclass Monad m => MonadIO (m :: Type -> Type) where

#

Monads in which IO computations may be embedded. Any monad built by applying a sequence of monad transformers to the IO monad will be an instance of this class.

Instances should satisfy the following laws, which state that liftIO is a transformer of monads:

```
liftIO . return = return
```

liftIO (m >>= f) = liftIO m >>= (liftIO . f)

Methods

liftIO :: IO a -> m a
Lift a computation from the IO monad. This allows us to run IO computations in any monadic stack, so long as it supports these kinds of operations (i.e. IO is the base monad for the stack).
Example
```
import Control.Monad.Trans.State -- from the "transformers" library

printState :: Show s => StateT s IO ()
printState = do
  state <- get
  liftIO $ print state
```
Had we omitted liftIO, we would have ended up with this error:
```
• Couldn't match type ‘IO’ with ‘StateT s IO’
 Expected type: StateT s IO ()
   Actual type: IO ()
```
The important part here is the mismatch between StateT s IO () and IO ().
Luckily, we know of a function that takes an IO a and returns an (m a): liftIO, enabling us to run the program and see the expected results:
```
> evalStateT printState "hello"
"hello"

> evalStateT printState 3
3
```

Instances21MonadIO, …

MonadIO QDefined in ghc-internal-10.0.0 · GHC.Internal.TH.Monad
MonadIO IODefined in ghc-internal-10.0.0 · GHC.Internal.Control.Monad.IO.Class
MonadIO m => MonadIO (CatchT m)Defined in exceptions-0.10.12 · Control.Monad.Catch.Pure
MonadIO m => MonadIO (DumbTerm m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.DumbTerm
MonadIO m => MonadIO (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
MonadIO m => MonadIO (InputT m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT
MonadIO m => MonadIO (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadIO m => MonadIO (ExceptT e m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Except
MonadIO m => MonadIO (IdentityT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Identity
MonadIO m => MonadIO (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadIO m => MonadIO (SelectT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Select
MonadIO m => MonadIO (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Lazy
MonadIO m => MonadIO (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadIO m => MonadIO (WriterT w m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Writer.CPS
(Monoid w, Functor m, MonadIO m) => MonadIO (AccumT w m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Accum
(Monoid w, MonadIO m) => MonadIO (WriterT w m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Writer.Lazy
(Monoid w, MonadIO m) => MonadIO (WriterT w m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Writer.Strict
MonadIO m => MonadIO (ContT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Cont
MonadIO m => MonadIO (RWST r w s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.RWS.CPS
(Monoid w, MonadIO m) => MonadIO (RWST r w s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.RWS.Lazy
(Monoid w, MonadIO m) => MonadIO (RWST r w s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.RWS.Strict

classclass Monad m => MonadReader r (m :: Type -> Type) where

#

Methods

ask :: m r

Instances7MonadReader, …

Monad m => MonadReader Handles (DumbTerm m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.DumbTerm
Monad m => MonadReader Handles (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
Monad m => MonadReader Actions (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
Monad m => MonadReader Terminal (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
(MonadReader r m, MonadTrans t, Monad (t m)) => MonadReader r (t m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
Monad m => MonadReader r (ReaderT r m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
Monad m => MonadReader s (StateT s m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads

classclass Monad m => MonadState s (m :: Type -> Type) where

#

Methods

get :: m s
put :: s -> m ()

Instances6MonadState

Monad m => MonadState Window (DumbTerm m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.DumbTerm
Monad m => MonadState TermPos (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
Monad m => MonadState TermRows (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
(MonadState s m, MonadTrans t, Monad (t m)) => MonadState s (t m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
Monad m => MonadState s (StateT s m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
MonadIO m => MonadState s (ReaderT (IORef s) m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads

classclass (forall (m :: Type -> Type). Monad m => Monad (t m)) => MonadTrans (t :: (Type -> Type) -> Type -> Type) where

#

The class of monad transformers. For any monad m, the result t m should also be a monad, and lift should be a monad transformation from m to t m, i.e. it should satisfy the following laws:

```
lift . return = return
```
```
lift (m >>= f) = lift m >>= (lift . f)
```

Since 0.6.0.0 and for GHC 8.6 and later, the requirement that t m be a Monad is enforced by the implication constraint forall m. Monad m => Monad (t m) enabled by the QuantifiedConstraints extension.

Ambiguity error with GHC 9.0 to 9.2.2

These versions of GHC have a bug (https://gitlab.haskell.org/ghc/ghc/-/issues/20582) which causes constraints like

(MonadTrans t, forall m. Monad m => Monad (t m)) => ...

to be reported as ambiguous. For transformers 0.6 and later, this can be fixed by removing the second constraint, which is implied by the first.

Methods

lift :: Monad m => m a -> t m a
Lift a computation from the argument monad to the constructed monad.

Instances20MonadTrans, …

MonadTrans CatchTDefined in exceptions-0.10.12 · Control.Monad.Catch.Pure
MonadTrans DumbTermDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.DumbTerm
MonadTrans DrawDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo
MonadTrans CmdMDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Command
MonadTrans InputTDefined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT
MonadTrans MaybeTDefined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Monoid w => MonadTrans (AccumT w)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Accum
Monoid w => MonadTrans (WriterT w)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Writer.Lazy
Monoid w => MonadTrans (WriterT w)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Writer.Strict
MonadTrans IdentityTDefined in transformers-0.6.3.0 · Control.Monad.Trans.Identity
MonadTrans (ExceptT e)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Except
MonadTrans (ReaderT r)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadTrans (SelectT r)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Select
MonadTrans (StateT s)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Lazy
MonadTrans (StateT s)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadTrans (WriterT w)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Writer.CPS
MonadTrans (ContT r)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Cont
Monoid w => MonadTrans (RWST r w s)Defined in transformers-0.6.3.0 · Control.Monad.Trans.RWS.Lazy
Monoid w => MonadTrans (RWST r w s)Defined in transformers-0.6.3.0 · Control.Monad.Trans.RWS.Strict
MonadTrans (RWST r w s)Defined in transformers-0.6.3.0 · Control.Monad.Trans.RWS.CPS

newtypenewtype MaybeT (m :: Type -> Type) a

#

The parameterizable maybe monad, a strict monad obtained by composing an arbitrary monad with the Maybe monad.

Computations are actions that may produce a value or exit.

The return function yields a computation that produces that value, while >>= sequences two subcomputations, exiting if either computation does.

Constructors

MaybeT
- runMaybeT :: m (Maybe a)

Instances36MonadTrans, MonadRWS, Generic1, MonadAccum, MonadError, MonadReader, …

MonadTrans MaybeTDefined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadRWS r w s m => MonadRWS r w s (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.RWS.Class
Functor m => Generic1 (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadAccum w m => MonadAccum w (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.Accum
The accumulated value 'survives' an error: even if the computation fails to deliver a result, we still have an accumulated value.
MonadError e m => MonadError e (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.Error.Class
MonadReader r m => MonadReader r (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.Reader.Class
MonadState s m => MonadState s (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadWriter w m => MonadWriter w (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.Writer.Class
MonadSelect r m => MonadSelect r (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.Select
'Extends' the possibilities considered by m to include Nothing; this means that Nothing gains a 'rank' (namely, a value of r), and the potential result could also be Nothing.
Monad m => Monad (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Functor m => Functor (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadFix m => MonadFix (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Monad m => MonadFail (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
(Functor m, Monad m) => Applicative (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Foldable f => Foldable (MaybeT f)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Traversable f => Traversable (MaybeT f)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
(Functor m, Monad m) => Alternative (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Monad m => MonadPlus (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadIO m => MonadIO (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadZip m => MonadZip (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Eq1 m => Eq1 (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Ord1 m => Ord1 (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Read1 m => Read1 (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Show1 m => Show1 (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Contravariant m => Contravariant (MaybeT m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
MonadCont m => MonadCont (MaybeT m)Defined in mtl-2.3.2 · Control.Monad.Cont.Class
MonadCatch m => MonadCatch (MaybeT m)Defined in exceptions-0.10.12 · Control.Monad.Catch
Catches exceptions from the base monad.
MonadMask m => MonadMask (MaybeT m)Defined in exceptions-0.10.12 · Control.Monad.Catch
MonadThrow m => MonadThrow (MaybeT m)Defined in exceptions-0.10.12 · Control.Monad.Catch
Throws exceptions into the base monad.
(Eq1 m, Eq a) => Eq (MaybeT m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
(Ord1 m, Ord a) => Ord (MaybeT m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
(Read1 m, Read a) => Read (MaybeT m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
(Show1 m, Show a) => Show (MaybeT m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
Generic (MaybeT m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
type Rep (MaybeT m a) = D1 ('MetaData "MaybeT" "Control.Monad.Trans.Maybe" "transformers-0.6.3.0-24a4" 'True) (C1 ('MetaCons "MaybeT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runMaybeT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (m (Maybe a)))))Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe
type Rep1 (MaybeT m) = D1 ('MetaData "MaybeT" "Control.Monad.Trans.Maybe" "transformers-0.6.3.0-24a4" 'True) (C1 ('MetaCons "MaybeT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runMaybeT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (m :.: Rec1 Maybe)))Defined in transformers-0.6.3.0 · Control.Monad.Trans.Maybe

newtypenewtype ReaderT r (m :: Type -> Type) a

#

The reader monad transformer, which adds a read-only environment to the given monad.

The return function ignores the environment, while m >>= k passes the inherited environment to both subcomputations:

image: images/bind-ReaderT.svg

ReaderT r m is strict if and only if m is.

Instances28Generic1, MonadAccum, MonadError, MonadWriter, MonadSelect, MonadState, …

Generic1 (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadAccum w m => MonadAccum w (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.Accum
MonadError e m => MonadError e (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.Error.Class
Monad m => MonadReader r (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.Reader.Class
MonadState s m => MonadState s (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadWriter w m => MonadWriter w (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.Writer.Class
MonadSelect r' m => MonadSelect r' (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.Select
Provides a read-only environment of type r to the 'strategy' function. However, the 'ranking' function (or more accurately, representation) has no access to r. Put another way, you can influence what values get chosen by changing r, but not how solutions are ranked.
MonadIO m => MonadState s (ReaderT (IORef s) m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
Monad m => MonadReader r (ReaderT r m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
MonadTrans (ReaderT r)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
(MonadIO m, MonadMask m) => CommandMonad (InputCmdT m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT
Monad m => Monad (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
Functor m => Functor (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadFix m => MonadFix (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadFail m => MonadFail (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
Applicative m => Applicative (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
Alternative m => Alternative (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadPlus m => MonadPlus (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadIO m => MonadIO (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadZip m => MonadZip (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
Contravariant m => Contravariant (ReaderT r m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
MonadCont m => MonadCont (ReaderT r m)Defined in mtl-2.3.2 · Control.Monad.Cont.Class
MonadCatch m => MonadCatch (ReaderT r m)Defined in exceptions-0.10.12 · Control.Monad.Catch
MonadMask m => MonadMask (ReaderT r m)Defined in exceptions-0.10.12 · Control.Monad.Catch
MonadThrow m => MonadThrow (ReaderT r m)Defined in exceptions-0.10.12 · Control.Monad.Catch
Generic (ReaderT r m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
type Rep (ReaderT r m a) = D1 ('MetaData "ReaderT" "Control.Monad.Trans.Reader" "transformers-0.6.3.0-24a4" 'True) (C1 ('MetaCons "ReaderT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runReaderT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (r -> m a))))Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader
type Rep1 (ReaderT r m) = D1 ('MetaData "ReaderT" "Control.Monad.Trans.Reader" "transformers-0.6.3.0-24a4" 'True) (C1 ('MetaCons "ReaderT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runReaderT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (FUN 'Many r :.: Rec1 m)))Defined in transformers-0.6.3.0 · Control.Monad.Trans.Reader

valuerunReaderT :: ReaderT r m a -> r -> m a

#

newtypenewtype StateT s (m :: Type -> Type) a

#

A state transformer monad parameterized by:

s - The state.
m - The inner monad.

The return function leaves the state unchanged, while >>= uses the final state of the first computation as the initial state of the second.

Instances25MonadAccum, MonadError, MonadWriter, MonadSelect, MonadState, MonadReader, …

MonadAccum w m => MonadAccum w (StateT s m)Defined in mtl-2.3.2 · Control.Monad.Accum
MonadError e m => MonadError e (StateT s m)Defined in mtl-2.3.2 · Control.Monad.Error.Class
MonadReader r m => MonadReader r (StateT s m)Defined in mtl-2.3.2 · Control.Monad.Reader.Class
Monad m => MonadState s (StateT s m)Defined in mtl-2.3.2 · Control.Monad.State.Class
MonadWriter w m => MonadWriter w (StateT s m)Defined in mtl-2.3.2 · Control.Monad.Writer.Class
MonadSelect w m => MonadSelect w (StateT s m)Defined in mtl-2.3.2 · Control.Monad.Select
'Readerizes' the state: the 'ranking' function can see a value of type s, but not modify it. Effectively, can be thought of as 'extending' the 'ranking' by all values in s, but which s gets given to any rank calls is predetermined by the 'outer state' (and cannot change).
Monad m => MonadState s (StateT s m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
Monad m => MonadReader s (StateT s m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Monads
MonadTrans (StateT s)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
(MonadIO m, MonadMask m) => CommandMonad (InputCmdT m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT
Monad m => Monad (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
Functor m => Functor (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadFix m => MonadFix (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadFail m => MonadFail (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
(Functor m, Monad m) => Applicative (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
(Functor m, MonadPlus m) => Alternative (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadPlus m => MonadPlus (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadIO m => MonadIO (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
Contravariant m => Contravariant (StateT s m)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
MonadCont m => MonadCont (StateT s m)Defined in mtl-2.3.2 · Control.Monad.Cont.Class
MonadCatch m => MonadCatch (StateT s m)Defined in exceptions-0.10.12 · Control.Monad.Catch
MonadMask m => MonadMask (StateT s m)Defined in exceptions-0.10.12 · Control.Monad.Catch
MonadThrow m => MonadThrow (StateT s m)Defined in exceptions-0.10.12 · Control.Monad.Catch
Generic (StateT s m a)Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict
type Rep (StateT s m a) = D1 ('MetaData "StateT" "Control.Monad.Trans.State.Strict" "transformers-0.6.3.0-24a4" 'True) (C1 ('MetaCons "StateT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runStateT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (s -> m (a, s)))))Defined in transformers-0.6.3.0 · Control.Monad.Trans.State.Strict

valuerunStateT :: StateT s m a -> s -> m (a, s)

#

valuebracketSet

:: (MonadMask m, MonadIO m)
=> IO a
-> a -> IO ()
-> a
-> m b
-> m b

#

Utility function for changing a property of a terminal for the duration of a computation.

valueclearLine :: Term m => LineChars -> m ()

#

valuedrawLine :: Term m => LineChars -> m ()

#

valueflushEventQueue :: (String -> IO ()) -> TChan Event -> IO ()

#

valueguardedEOF :: (Handle -> IO a) -> Handle -> MaybeT IO a

#

valuehGetByte :: Handle -> MaybeT IO Word8

#

Returns one 8-bit word. Needs to be wrapped by hWithBinaryMode.

valuehGetLocaleLine :: Handle -> MaybeT IO ByteString

#

Utility function to correctly get a line of input as an undecoded ByteString.

valuehMaybeReadNewline :: Handle -> IO ()

#

valuehWithBinaryMode :: (MonadIO m, MonadMask m) => Handle -> m a -> m a

#

Utility function since we're not using the new IO library yet.

valueisTerminalStyle :: RunTerm -> Bool

#

Are we using terminal-style interaction?

valuekeyEventLoop :: IO [Event] -> TChan Event -> IO Event

#

valuemapEvalTerm

:: forall a. n a -> m a
-> forall a. m a -> n a
-> EvalTerm n
-> EvalTerm m

#

valuematchInit :: Eq a => [a] -> [a] -> ([a], [a])

#

valuereturnOnEOF :: MonadMask m => a -> m a -> m a

#

valuesaveKeys :: TChan Event -> [Key] -> IO ()

#

classclass (MonadReader Prefs m, MonadReader Layout m, MonadIO m, MonadMask m) => CommandMonad (m :: Type -> Type) where

#

Methods

runCompletion :: (String, String) -> m (String, [Completion])

Instances2CommandMonad

(MonadIO m, MonadMask m) => CommandMonad (InputCmdT m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT
(MonadTrans t, CommandMonad m, MonadReader Prefs (t m), MonadIO (t m), MonadMask (t m), MonadReader Layout (t m)) => CommandMonad (t m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Term

datadata EvalTerm (m :: Type -> Type)

#

Constructors

forall n. (Term n, CommandMonad n) => EvalTerm (forall a. n a -> m a) (forall a. m a -> n a)

datadata Event

#

Constructors

WindowResize
KeyInput [Key]
ErrorEvent SomeException
ExternalPrint String

Instances1Show

Show EventDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Term

datadata FileOps

#

Operations needed for file-style interaction.

Backends can assume that getLocaleLine, getLocaleChar and maybeReadNewline are "wrapped" by wrapFileInput.

Constructors

FileOps
- withoutInputEcho :: forall (m :: Type -> Type) a. (MonadIO m, MonadMask m) => m a -> m a
  Perform an action without echoing input.
- wrapFileInput :: forall a. IO a -> IO a
- getLocaleLine :: MaybeT IO String
- getLocaleChar :: MaybeT IO Char
- maybeReadNewline :: IO ()

datadata Interrupt

#

Interrupt

Instances3Eq, Show, Exception

Eq InterruptDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Term
Show InterruptDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Term
Exception InterruptDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Term

datadata Layout

#

Constructors

Layout
- width :: Int
- height :: Int

Instances3Eq, Show, CommandMonad

Eq LayoutDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Term
Show LayoutDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Term
(MonadIO m, MonadMask m) => CommandMonad (InputCmdT m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT

datadata RunTerm

#

Constructors

RunTerm
- putStrOut :: String -> IO ()
  Write unicode characters to stdout.
- termOps :: Either TermOps FileOps
- wrapInterrupt :: forall a (m :: Type -> Type). (MonadIO m, MonadMask m) => m a -> m a
- closeTerm :: IO ()

classclass (MonadReader Layout m, MonadIO m, MonadMask m) => Term (m :: Type -> Type) where

#

Methods

reposition :: Layout -> LineChars -> m ()
moveToNextLine :: LineChars -> m ()
printLines :: [String] -> m ()
drawLineDiff :: LineChars -> LineChars -> m ()
clearLayout :: m ()
ringBell :: Bool -> m ()

Instances2Term

(MonadIO m, MonadMask m, MonadReader Layout m) => Term (DumbTerm m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.DumbTerm
(MonadIO m, MonadMask m, MonadReader Layout m) => Term (Draw m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.Backend.Terminfo

datadata TermOps

#

Operations needed for terminal-style interaction.

Constructors

TermOps
- getLayout :: IO Layout
- withGetEvent :: forall (m :: Type -> Type) a. CommandMonad m => (m Event -> m a) -> m a
- evalTerm :: forall (m :: Type -> Type). CommandMonad m => EvalTerm m
- saveUnusedKeys :: [Key] -> IO ()
- externalPrint :: String -> IO ()

valuectrlChar :: Char -> Key

#

valuectrlKey :: Key -> Key

#

valuemetaChar :: Char -> Key

#

valuemetaKey :: Key -> Key

#

valuenoModifier :: Modifier

#

valueparseKey :: String -> Maybe Key

#

valuesetControlBits :: Char -> Char

#

valuesimpleChar :: Char -> Key

#

valuesimpleKey :: BaseKey -> Key

#

datadata BaseKey

#

Instances3Eq, Ord, Show

Eq BaseKeyDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key
Ord BaseKeyDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key
Show BaseKeyDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key

datadata Key

#

Constructors

Key Modifier BaseKey

Instances3Eq, Ord, Show

Eq KeyDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key
Ord KeyDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key
Show KeyDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key

datadata Modifier

#

Constructors

Modifier
- hasControl :: Bool
- hasMeta :: Bool
- hasShift :: Bool

Instances3Eq, Ord, Show

Eq ModifierDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key
Ord ModifierDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key
Show ModifierDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Key

valueaddNum :: Int -> ArgMode s -> ArgMode s

#

valueaddPasswordChar :: Char -> Password -> Password

#

valueafterChar :: (Char -> Bool) -> InsertMode -> Bool

#

valueappendFromCommandMode :: CommandMode -> InsertMode

#

valueapplyArg :: (s -> s) -> ArgMode s -> s

#

valueapplyCmdArg

:: InsertMode -> InsertMode
-> ArgMode CommandMode
-> CommandMode

#

valueatEnd :: (Char -> Bool) -> InsertMode -> Bool

#

valueatStart :: (Char -> Bool) -> InsertMode -> Bool

#

valuebaseChar :: Grapheme -> Char

#

valuebeforeChar :: (Char -> Bool) -> InsertMode -> Bool

#

valuedeleteChar :: CommandMode -> CommandMode

#

valuedeleteNext :: InsertMode -> InsertMode

#

valuedeletePasswordChar :: Password -> Password

#

valuedeletePrev :: InsertMode -> InsertMode

#

valueemptyIM :: InsertMode

#

valueenterCommandMode :: InsertMode -> CommandMode

#

valueenterCommandModeRight :: InsertMode -> CommandMode

#

valuegoLeftUntil :: (InsertMode -> Bool) -> InsertMode -> InsertMode

#

valuegoRightUntil :: (InsertMode -> Bool) -> InsertMode -> InsertMode

#

valuegraphemesToString :: [Grapheme] -> String

#

valueinsertChar :: Char -> InsertMode -> InsertMode

#

Insert one character, which may be combining, to the left of the cursor.

valueinsertFromCommandMode :: CommandMode -> InsertMode

#

valueinsertGraphemes :: [Grapheme] -> InsertMode -> InsertMode

#

valueinsertString :: String -> InsertMode -> InsertMode

#

Insert a sequence of characters to the left of the cursor.

valuelengthToEnd :: LineChars -> Int

#

Compute the number of characters under and to the right of the cursor.

valuelineChars :: LineState s => Prefix -> s -> LineChars

#

Accessor function for the various backends.

valuelistRestore :: Save s => [Grapheme] -> s

#

valuelistSave :: Save s => s -> [Grapheme]

#

valuemapBaseChars :: (Char -> Char) -> [Grapheme] -> [Grapheme]

#

valuemodifyBaseChar :: (Char -> Char) -> Grapheme -> Grapheme

#

valueoverChar :: (Char -> Bool) -> InsertMode -> Bool

#

valuepasteGraphemesAfter :: [Grapheme] -> CommandMode -> CommandMode

#

valuepasteGraphemesBefore :: [Grapheme] -> CommandMode -> CommandMode

#

valuereplaceChar :: Char -> CommandMode -> CommandMode

#

valuereplaceCharIM :: Char -> InsertMode -> InsertMode

#

valueskipLeft :: (Char -> Bool) -> InsertMode -> InsertMode

#

valueskipRight :: (Char -> Bool) -> InsertMode -> InsertMode

#

valuestartArg :: Int -> s -> ArgMode s

#

valuestringToGraphemes :: String -> [Grapheme]

#

Converts a string into a sequence of graphemes.

NOTE: Drops any initial, unattached combining characters.

valuetransposeChars :: InsertMode -> InsertMode

#

valuewithCommandMode :: (InsertMode -> InsertMode) -> CommandMode -> CommandMode

#

datadata ArgMode s

#

Used for commands which take an integer argument.

Constructors

ArgMode
- arg :: Int
- argState :: s

Instances4Functor, LineState, Result, Save

Functor ArgModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState s => LineState (ArgMode s)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result s => Result (ArgMode s)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Save s => Save (ArgMode s)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

datadata CommandMode

#

Used by vi mode. Considers the cursor to be located over some specific character. The first list is reversed.

Constructors

CMode [Grapheme] Grapheme [Grapheme]
CEmpty

Instances5Show, LineState, Move, Result, Save

Show CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Move CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Save CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

datadata Grapheme

#

A Grapheme is a fundamental unit of display for the UI. Several characters in sequence can represent one grapheme; for example, an a followed by the diacritic '\768' should be treated as one unit.

Instances3Eq, Show, CommandMonad

Eq GraphemeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Show GraphemeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
(MonadIO m, MonadMask m) => CommandMonad (InputCmdT m)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.InputT

datadata InsertMode

#

The standard line state representation; considers the cursor to be located between two characters. The first list is reversed.

Constructors

IMode [Grapheme] [Grapheme]

Instances6Eq, Show, LineState, Move, Result, Save

Eq InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Show InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Move InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Save InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

typetype LineChars = ([Grapheme], [Grapheme])

#

The characters in the line (with the cursor in the middle). NOT in a zippered format; both lists are in the order left->right that appears on the screen.

classclass LineState s where

#

This class abstracts away the internal representations of the line state, for use by the drawing actions. Line state is generally stored in a zipper format.

Methods

beforeCursor :: Prefix -> s -> [Grapheme]
afterCursor :: s -> [Grapheme]

Instances7LineState, …

LineState SearchModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Command.History
LineState CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState MessageDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState PasswordDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
LineState SearchEntryDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Vi
LineState s => LineState (ArgMode s)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

newtypenewtype Message

#

Constructors

Message
- messageText :: String

Instances1LineState

LineState MessageDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

classclass Move s where

#

Methods

goLeft :: s -> s
goRight :: s -> s
moveToStart :: s -> s
moveToEnd :: s -> s

Instances2Move

Move CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Move InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

datadata Password

#

Constructors

Password
- passwordState :: [Char]
  reversed
- passwordChar :: Maybe Char

Instances2LineState, Result

LineState PasswordDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result PasswordDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

typetype Prefix = [Grapheme]

#

classclass LineState s => Result s where

#

Methods

toResult :: s -> String

Instances5Result

Result SearchModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.Command.History
Result CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result PasswordDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Result s => Result (ArgMode s)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

classclass LineState s => Save s where

#

Methods

save :: s -> InsertMode
restore :: InsertMode -> s

Instances3Save

Save CommandModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Save InsertModeDefined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState
Save s => Save (ArgMode s)Defined in haskeline-0.8.5.0 · System.Console.Haskeline.LineState

datadata Behavior

#

Haskeline has two ways of interacting with the user:

"Terminal-style" interaction provides an rich user interface by connecting to the user's terminal (which may be different than stdin or stdout).
"File-style" interaction treats the input as a simple stream of characters, for example when reading from a file or pipe. Input functions (e.g., getInputLine) print the prompt to stdout.

A Behavior is a method for deciding at run-time which type of interaction to use.

For most applications (e.g., a REPL), defaultBehavior should have the correct effect.

Constructors

Behavior (IO RunTerm)

valuedebugTerminalKeys :: IO a

#

This function may be used to debug Haskeline's input.

It loops indefinitely; every time a key is pressed, it will print that key as it was recognized by Haskeline. Pressing Ctrl-C will stop the loop.

Haskeline's behavior may be modified by editing your ~/.haskeline file. For details, see: https://github.com/judah/haskeline/wiki/CustomKeyBindings

Methods

Example

Methods

Methods

Ambiguity error with GHC 9.0 to 9.2.2

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