System.Console.Style

This library provides styled text output using ANSI escape sequences. The main feature is that the library keeps track of a stack of the active styles using a state monad. This makes it easy to use this library for a pretty printer with nested annotations, e.g., wl-pprint-console.

Warning: Windows supports is currently not implemented, but is planned (by using ansi-terminal or by directly using the ffi).

Example:

basicExample :: IO ()
basicExample = runWithStyle [FgColor Blue] $ do
  withStyle [Bold] $ liftIO $ putStr "Bold Blue"

  setStyle [Save, Italic, BgColor Red]
  liftIO $ putStr "Italic Red"
  setStyle [Restore]

  setStyle [Under]
  liftIO $ putStr "Under Blue"
  setStyle [Reset]

  liftIO $ putStrLn "Normal output"

For many more examples, see the Example.hs file.

Documentation

data Color

Constructors

DefaultColor

Black

Red

Green

Yellow

Blue

Magenta

Cyan

White

DullBlack

DullRed

DullGreen

DullYellow

DullBlue

DullMagenta

DullCyan

DullWhite

Color256 !Word8

RGB !Word8 !Word8 !Word8

Instances

Eq Color

Methods

(==) :: Color -> Color -> Bool

(/=) :: Color -> Color -> Bool

Ord Color

Methods

compare :: Color -> Color -> Ordering

(<) :: Color -> Color -> Bool

(<=) :: Color -> Color -> Bool

(>) :: Color -> Color -> Bool

(>=) :: Color -> Color -> Bool

max :: Color -> Color -> Color

min :: Color -> Color -> Color

Show Color

Methods

showsPrec :: Int -> Color -> ShowS

show :: Color -> String

showList :: [Color] -> ShowS

class HasStyle s where

Minimal complete definition

getStyle, putStyle

Methods

getStyle :: s -> Style

putStyle :: Style -> s -> s

Instances

HasStyle Style

Methods

getStyle :: Style -> Style

putStyle :: Style -> Style -> Style

data SetStyle

Constructors

Bold

NotBold

Italic

NotItalic

Under

NotUnder

Invert

NotInvert

Save

Restore

Reset

Blink

NotBlink

FgColor !Color

BgColor !Color

Instances

Eq SetStyle

Methods

(==) :: SetStyle -> SetStyle -> Bool

(/=) :: SetStyle -> SetStyle -> Bool

Ord SetStyle

Methods

compare :: SetStyle -> SetStyle -> Ordering

(<) :: SetStyle -> SetStyle -> Bool

(<=) :: SetStyle -> SetStyle -> Bool

(>) :: SetStyle -> SetStyle -> Bool

(>=) :: SetStyle -> SetStyle -> Bool

max :: SetStyle -> SetStyle -> SetStyle

min :: SetStyle -> SetStyle -> SetStyle

Show SetStyle

Methods

showsPrec :: Int -> SetStyle -> ShowS

show :: SetStyle -> String

showList :: [SetStyle] -> ShowS

data Style

Instances

HasStyle Style

Methods

getStyle :: Style -> Style

putStyle :: Style -> Style -> Style

data Term

Constructors

TermDumb

Term8

Term256

TermRGB

TermWin

Instances

Eq Term

Methods

(==) :: Term -> Term -> Bool

(/=) :: Term -> Term -> Bool

Show Term

Methods

showsPrec :: Int -> Term -> ShowS

show :: Term -> String

showList :: [Term] -> ShowS

defaultStyle :: Term -> Style

(defaultStyle term) returns the default style configured with terminal type term.

hDefaultStyle :: Handle -> Term -> Style

(hDefaultStyle handle term) return the default (initial) style configured with the file handle handle and terminal type term@.

Every style has a single associated handle.

hGetTerm :: MonadIO m => Handle -> m Term

The action (hGetTerm handle) determines the terminal type of the file handle handle.

The terminal type is determined by checking if the file handle points to a device and by looking at the $TERM environment variable.

hRunStyle :: MonadIO m => Handle -> StateT Style m a -> m a

The action (hRunStyle handle action) runs the StateT monad transformer providing the active style for the given action.

hRunWithStyle :: (MonadIO m, Foldable f) => Handle -> f SetStyle -> StateT Style m a -> m a

The action (hRunWithStyle handle cmd action) runs the StateT monad transformer providing the active style for the given action.

The output on handle within the action is modified by the given style commands cmd. The style is restored to the defaults afterwards.

runStyle :: Term -> State Style a -> a

The action (runStyle term action) runs the State monad providing the active style for the given action.

runWithStyle :: (MonadIO m, Foldable f) => f SetStyle -> StateT Style m a -> m a

The action (runWithStyle cmd action) runs the StateT monad transformer providing the active style for the given action.

The output on stdout within the action is modified by the given style commands cmd. The style is restored to the defaults afterwards.

setStyle :: (MonadIO m, MonadState s m, HasStyle s, Foldable f) => f SetStyle -> m ()

The action (setStyle cmd) modifies the current style by executing the style commands cmd.

styleCode' :: Foldable f => Style -> f SetStyle -> (Style, String)

The function (styleCode' style cmd) returns the modified style status and ANSI code corresponding to the style commands cmd.

styleCode :: (MonadState s m, HasStyle s, Foldable f) => f SetStyle -> m String

The action (styleCode cmd) returns the ANSI code corresponding to the style commands cmd. This action must be executed within a monadic context providing the current style status.

withStyle :: (MonadIO m, MonadState s m, HasStyle s, Foldable f) => f SetStyle -> m a -> m a

The action (withStyle cmd action) executes the action with the current style modified by the style commands cmd.

The style is restored to the previously active style afterwards.