This module provides a stateful, IO-based interface to Haskeline, which may be easier to integrate into some existing programs or libraries.
It is strongly recommended to use the safer, monadic API of System.Console.Haskeline, if possible, rather than the explicit state management functions of this module.
The equivalent REPL example is:
import System.Console.Haskeline import System.Console.Haskeline.IO import Control.Concurrent main = bracketOnError (initializeInput defaultSettings) cancelInput -- This will only be called if an exception such -- as a SigINT is received. (\hd -> loop hd >> closeInput hd) where loop :: InputState -> IO () loop hd = do minput <- queryInput hd (getInputLine "% ") case minput of Nothing -> return () Just "quit" -> return () Just input -> do queryInput hd $ outputStrLn $ "Input was: " ++ input loop hd
Initialize a session of line-oriented user interaction.
Finish and clean up the line-oriented user interaction session. Blocks on an
existing call to
Cancel and clean up the user interaction session. Does not block on an existing
Run one action (for example,
getInputLine) as part of a session of user interaction.
For example, multiple calls to
queryInput using the same
InputState will share
the same input history. In constrast, multiple calls to
runInputT will use distinct
histories unless they share the same history file.
This function should not be called on a closed or cancelled