System.Console.Haskeline.Class

haskeline-class-0.6: Class interface for working with Haskeline

Portability	FlexibleInstances, MultiPatamTypeClasses, UndecidableInstances, GeneralizedNewtypeDeriving
Stability	experimental
Maintainer	Antoine Latter <aslatter@gmail.com>

Description

Haskeline provides all of its functionality within the scope of a monad transformer. This module adds two pieces to this:

- Introduced here is a type-class which defines the operations supported by the Haskeline monad transformer - MonadHaskeline
- Also is a newtype wrapper around Haskeline's InputT, called HaskelineT. Sadly, InputT defines ints own instance of the mtl MonadState, which is no good for folks wanting to use InputT in an existing monad transformer stack.

HaskelineT also has an instance of MonadState, but it merely lifts the functions further in the transformer stack.

Large portions of the Haskeline functionality are re-exported here for convinience.

Synopsis

data HaskelineT m a

runHaskelineT :: MonadException m => Settings m -> HaskelineT m a -> m a

runHaskelineTWithPrefs :: MonadException m => Prefs -> Settings m -> HaskelineT m a -> m a

class MonadException m => MonadHaskeline m where

getInputLine :: String -> m (Maybe String)

getInputChar :: String -> m (Maybe Char)

outputStr :: String -> m ()

outputStrLn :: String -> m ()

data Settings m = Settings {

complete :: CompletionFunc m

historyFile :: Maybe FilePath

autoAddHistory :: Bool

}

defaultSettings :: MonadIO m => Settings m

setComplete :: CompletionFunc m -> Settings m -> Settings m

data Prefs

readPrefs :: FilePath -> IO Prefs

defaultPrefs :: Prefs

data Interrupt = Interrupt

handleInterrupt :: MonadException m => m a -> m a -> m a

module System.Console.Haskeline.Completion

module System.Console.Haskeline.MonadException

Documentation

data HaskelineT m a

Source

Instances

MonadTrans HaskelineT

MonadState s m => MonadState s (HaskelineT m)

Monad m => Monad (HaskelineT m)

Monad m => Functor (HaskelineT m)

Monad m => Applicative (HaskelineT m)

MonadIO m => MonadIO (HaskelineT m)

MonadException m => MonadException (HaskelineT m)

MonadException m => MonadHaskeline (HaskelineT m)

runHaskelineT :: MonadException m => Settings m -> HaskelineT m a -> m a

Source

runHaskelineTWithPrefs :: MonadException m => Prefs -> Settings m -> HaskelineT m a -> m a

Source

class MonadException m => MonadHaskeline m where

Source

Methods

getInputLine :: String -> m (Maybe String)

Source

getInputChar :: String -> m (Maybe Char)

Source

outputStr :: String -> m ()

Source

outputStrLn :: String -> m ()

Source

Instances

MonadException m => MonadHaskeline (InputT m)

MonadException m => MonadHaskeline (HaskelineT m)

MonadHaskeline m => MonadHaskeline (StateT s m)

data Settings m

Source

Application-specific customizations to the user interface.

Constructors

Settings

complete :: CompletionFunc m	Custom tab completion.
historyFile :: Maybe FilePath	Where to read/write the history at the start and end of each line input session.
autoAddHistory :: Bool	If `True`, each nonblank line returned by `getInputLine` will be automatically added to the history.

Instances

Monad m => MonadReader (Settings m) (InputT m)

defaultSettings :: MonadIO m => Settings m

Source

A useful default. In particular:

defaultSettings = Settings { complete = completeFilename, historyFile = Nothing, autoAddHistory = True }

setComplete :: CompletionFunc m -> Settings m -> Settings m

Source

Because complete is the only field of Settings depending on m, the expression defaultSettings {completionFunc = f} leads to a type error from being too general. This function works around that issue, and may become unnecessary if another field depending on m is added.

data Prefs

Source

Prefs allow the user to customize the line-editing interface. They are read by default from ~/.haskeline; to override that behavior, use readPrefs and runInputTWithPrefs.

Each line of a .haskeline file defines one field of the Prefs datatype; field names are case-insensitive and unparseable lines are ignored. For example:

editMode: Vi completionType: MenuCompletion maxhistorysize: Just 40

Instances

Show Prefs

Monad m => MonadReader Prefs (InputT m)

readPrefs :: FilePath -> IO Prefs

Source

Read Prefs from a given file. If there is an error reading the file, the defaultPrefs will be returned.

defaultPrefs :: Prefs

Source

The default preferences which may be overwritten in the .haskeline file.

data Interrupt

Source