ansi-terminal by Max Bolingbroke

ANSI terminal support for Haskell, which allows:

• Cursor movement
• Screen and line clearing
• Color output
• Showing or hiding the cursor
• Changing the console title (though this is not strictly part of ANSI, it is widely supported in Unix)

It is compatible with Windows (via an emulation layer) and those Unixes with ANSI terminals.

If you like this, you may be interested in ansi-wl-pprint, which provides a pretty-printer that can construct strings containing ANSI colorisation.

Not all of the ANSI escape codes are provided by this module, but most (if not all) of the popular and well supported ones are. For a full list, have a look at the current version of the API. Each supported escape code or family of codes has a corresponding function that comes in three variants:

• A straight IO variant that doesn't take a Handle and just applies the ANSI escape code to the terminal attached to stdout
• An IO variant similar to above, but which takes a Handle to which the ANSI escape should be applied
• A String variant that returns a literal string that should be included to get the effect of the code. This is the only one of the three API variants that only works on Unix-like operating systems: on Windows these strings will always be blank!

A full example is available, but for a taste of how the library works try the following code:

import System.Console.ANSI

main = do
    setCursorPosition 5 0
    setTitle "ANSI Terminal Short Example"

    setSGR [ SetConsoleIntensity BoldIntensity
           , SetColor Foreground Vivid Red
           ]
    putStr "Hello"
    
    setSGR [ SetConsoleIntensity NormalIntensity
           , SetColor Foreground Vivid White
           , SetColor Background Dull Blue
           ]
    putStrLn "World!"