GNU ncurses is a library for creating command-line application with pseudo-graphical interfaces. This package is a nice, modern binding to GNU ncurses.
Code: https://john-millikin.com/code/haskell-ncurses (GitHub mirror)
The following example is a program that displays the message "Hello world!" until the user hits Q:
import UI.NCurses
main :: IO ()
main = runCurses $ do
setEcho False
w <- defaultWindow
updateWindow w $ do
moveCursor 1 10
drawString "Hello world!"
moveCursor 3 10
drawString "(press q to quit)"
moveCursor 0 0
render
waitFor w (\ev -> ev == EventCharacter 'q' || ev == EventCharacter 'Q')
waitFor :: Window -> (Event -> Bool) -> Curses ()
waitFor w p = loop where
loop = do
ev <- getEvent w Nothing
case ev of
Nothing -> loop
Just ev' -> if p ev' then return () else loop