{-|
Module      : Z.IO.StdStream.Ansi
Description : Ansi control code sequences
Copyright   : (c) Winterland, 2017-2020
License     : BSD
Maintainer  : winterland1989@gmail.com
Stability   : experimental
Portability : non-portable

Provides utilities to build <ANSI code sequences https://en.wikipedia.org/wiki/ANSI_escape_code>.

@
> putStd . bold . italicize . color Red  $ "hello"
hello   -- bold, italicize and red
@

-}

module Z.IO.StdStream.Ansi
  ( -- * Style modifier
    bold, italicize, underline,
    color, color', palette, palette', rgb, rgb',
    -- * Control codes
    cursorUp, cursorDown, cursorForward, cursorBackward,
    cursorDownLine, cursorUpLine ,
    setCursorColumn, setCursorPosition, saveCursor, restoreCursor,
    clearFromCursorToScreenEnd, clearFromCursorToScreenBeginning, clearScreen,
    clearFromCursorToLineEnd, clearFromCursorToLineBeginning, clearLine,
    scrollPageUp, scrollPageDown,
    hideCursor, showCursor,
    setTitle,
    -- * Style codes
    reset,
    boldIntensity, faintIntensity, resetIntensity,
    italicized, noItalicized,
    singleUnderline, doubleUnderline, noUnderline,
    slowBlink, rapidBlink, blinkOff,
    conceal, reveal,
    invert, invertOff,
    setForeground, setBrightForeground, setBackground, setBrightBackground,
    setPaletteForeground, setPaletteBackground,
    setRGBForeground, setRGBBackground,
    setDefaultForeground, setDefaultBackground,
    AnsiColor(..), PaletteColor, RGBColor,
    -- * Internal helper
    csi, sgr, colorToCode
  ) where

import qualified Z.Data.Builder as B
import qualified Z.Data.Text    as T
import Data.Word
import GHC.Generics

csi :: [Int]  -- ^ List of parameters for the control sequence
    -> B.Builder () -- ^ Character(s) that identify the control function
    -> B.Builder ()
csi :: [Int] -> Builder () -> Builder ()
csi [Int]
args Builder ()
code = do
    Char -> Builder ()
B.char8 Char
'\ESC'
    Char -> Builder ()
B.char8 Char
'['
    Builder () -> (Int -> Builder ()) -> [Int] -> Builder ()
forall a. Builder () -> (a -> Builder ()) -> [a] -> Builder ()
B.intercalateList (Char -> Builder ()
B.char8 Char
';') Int -> Builder ()
forall a. (Integral a, Bounded a) => a -> Builder ()
B.int [Int]
args
    Builder ()
code

cursorUp, cursorDown, cursorForward, cursorBackward
  :: Int -- ^ Number of lines or characters to move
  -> B.Builder ()
cursorDownLine, cursorUpLine :: Int -- ^ Number of lines to move
                                     -> B.Builder ()
cursorUp :: Int -> Builder ()
cursorUp Int
n       = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'A')
cursorDown :: Int -> Builder ()
cursorDown Int
n     = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'B')
cursorForward :: Int -> Builder ()
cursorForward Int
n  = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'C')
cursorBackward :: Int -> Builder ()
cursorBackward Int
n = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'D')
cursorDownLine :: Int -> Builder ()
cursorDownLine Int
n = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'E')
cursorUpLine :: Int -> Builder ()
cursorUpLine Int
n   = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'F')

-- | Code to move the cursor to the specified column. The column numbering is
-- 1-based (that is, the left-most column is numbered 1).
setCursorColumn :: Int -- ^ 1-based column to move to
                -> B.Builder ()
setCursorColumn :: Int -> Builder ()
setCursorColumn Int
n = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'G')

-- | Code to move the cursor to the specified position (row and column). The
-- position is 1-based (that is, the top-left corner is at row 1 column 1).
setCursorPosition :: Int -- ^ 1-based row to move to
                  -> Int -- ^ 1-based column to move to
                  -> B.Builder ()
setCursorPosition :: Int -> Int -> Builder ()
setCursorPosition Int
n Int
m = [Int] -> Builder () -> Builder ()
csi [Int
n, Int
m] (Char -> Builder ()
B.char8 Char
'G')

saveCursor, restoreCursor :: B.Builder ()
saveCursor :: Builder ()
saveCursor    = Char -> Builder ()
B.char8 Char
'\ESC' Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Char -> Builder ()
B.char8 Char
'7'
restoreCursor :: Builder ()
restoreCursor = Char -> Builder ()
B.char8 Char
'\ESC' Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Char -> Builder ()
B.char8 Char
'8'


clearFromCursorToScreenEnd, clearFromCursorToScreenBeginning, clearScreen :: B.Builder ()
clearFromCursorToLineEnd, clearFromCursorToLineBeginning, clearLine :: B.Builder ()

clearFromCursorToScreenEnd :: Builder ()
clearFromCursorToScreenEnd       = [Int] -> Builder () -> Builder ()
csi [Int
0] (Char -> Builder ()
B.char8 Char
'J')
clearFromCursorToScreenBeginning :: Builder ()
clearFromCursorToScreenBeginning = [Int] -> Builder () -> Builder ()
csi [Int
1] (Char -> Builder ()
B.char8 Char
'J')
clearScreen :: Builder ()
clearScreen                      = [Int] -> Builder () -> Builder ()
csi [Int
2] (Char -> Builder ()
B.char8 Char
'J')
clearFromCursorToLineEnd :: Builder ()
clearFromCursorToLineEnd         = [Int] -> Builder () -> Builder ()
csi [Int
0] (Char -> Builder ()
B.char8 Char
'K')
clearFromCursorToLineBeginning :: Builder ()
clearFromCursorToLineBeginning   = [Int] -> Builder () -> Builder ()
csi [Int
1] (Char -> Builder ()
B.char8 Char
'K')
clearLine :: Builder ()
clearLine                        = [Int] -> Builder () -> Builder ()
csi [Int
2] (Char -> Builder ()
B.char8 Char
'K')

scrollPageUp, scrollPageDown :: Int -- ^ Number of lines to scroll by
                             -> B.Builder()
scrollPageUp :: Int -> Builder ()
scrollPageUp Int
n   = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'S')
scrollPageDown :: Int -> Builder ()
scrollPageDown Int
n = [Int] -> Builder () -> Builder ()
csi [Int
n] (Char -> Builder ()
B.char8 Char
'T')

hideCursor, showCursor :: B.Builder ()
hideCursor :: Builder ()
hideCursor = [Int] -> Builder () -> Builder ()
csi [] Builder ()
"?25l"
showCursor :: Builder ()
showCursor = [Int] -> Builder () -> Builder ()
csi [] Builder ()
"?25h"

-- | XTerm control sequence to set the Icon Name and Window Title.
setTitle :: T.Text  -- ^ New Icon Name and Window Title
         -> B.Builder ()
setTitle :: Text -> Builder ()
setTitle Text
title = do
    Builder ()
"\ESC]0;"
    Text -> Builder ()
B.text ((Char -> Bool) -> Text -> Text
T.filter (Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
/= Char
'\007') Text
title)
    Char -> Builder ()
B.char8 Char
'\007'

sgr :: [Word8]  -- ^ List of sgr code for the control sequence
    -> B.Builder ()
sgr :: [Word8] -> Builder ()
sgr [Word8]
args = do
    Char -> Builder ()
B.char8 Char
'\ESC'
    Char -> Builder ()
B.char8 Char
'['
    Builder () -> (Word8 -> Builder ()) -> [Word8] -> Builder ()
forall a. Builder () -> (a -> Builder ()) -> [a] -> Builder ()
B.intercalateList (Char -> Builder ()
B.char8 Char
';') Word8 -> Builder ()
forall a. (Integral a, Bounded a) => a -> Builder ()
B.int [Word8]
args
    Char -> Builder ()
B.char8 Char
'm'

reset :: B.Builder ()
reset :: Builder ()
reset = [Word8] -> Builder ()
sgr [Word8
0]

boldIntensity, faintIntensity, resetIntensity :: B.Builder ()
boldIntensity :: Builder ()
boldIntensity  = [Word8] -> Builder ()
sgr [Word8
1]
faintIntensity :: Builder ()
faintIntensity = [Word8] -> Builder ()
sgr [Word8
2]
resetIntensity :: Builder ()
resetIntensity    = [Word8] -> Builder ()
sgr [Word8
22]

bold :: B.Builder () -> B.Builder ()
bold :: Builder () -> Builder ()
bold Builder ()
t = Builder ()
boldIntensity Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Builder ()
t Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Builder ()
resetIntensity

italicized, noItalicized :: B.Builder ()
italicized :: Builder ()
italicized      = [Word8] -> Builder ()
sgr [Word8
3]
noItalicized :: Builder ()
noItalicized    = [Word8] -> Builder ()
sgr [Word8
23]

-- | Italicize some text
italicize :: B.Builder () -> B.Builder ()
italicize :: Builder () -> Builder ()
italicize Builder ()
t = Builder ()
italicized Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Builder ()
t Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Builder ()
noItalicized

singleUnderline, doubleUnderline, noUnderline :: B.Builder ()
singleUnderline :: Builder ()
singleUnderline = [Word8] -> Builder ()
sgr [Word8
4]
doubleUnderline :: Builder ()
doubleUnderline = [Word8] -> Builder ()
sgr [Word8
21]
noUnderline :: Builder ()
noUnderline   = [Word8] -> Builder ()
sgr [Word8
24]

-- | Add single underline to some text
underline  :: B.Builder () -> B.Builder ()
underline :: Builder () -> Builder ()
underline Builder ()
t = Builder ()
singleUnderline Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Builder ()
t Builder () -> Builder () -> Builder ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Builder ()
singleUnderline

slowBlink, rapidBlink, blinkOff :: B.Builder ()
-- | less than 150 per minute
slowBlink :: Builder ()
slowBlink   = [Word8] -> Builder ()
sgr [Word8
5]
-- | MS-DOS ANSI.SYS, 150+ per minute; not widely supported
rapidBlink :: Builder ()
rapidBlink  = [Word8] -> Builder ()
sgr [Word8
6]
blinkOff :: Builder ()
blinkOff     = [Word8] -> Builder ()
sgr [Word8
25]

conceal, reveal :: B.Builder ()
-- | Aka Hide, not widely supported.
conceal :: Builder ()
conceal = [Word8] -> Builder ()
sgr [Word8
8]
reveal :: Builder ()
reveal = [Word8] -> Builder ()
sgr [Word8
28]

invert, invertOff :: B.Builder ()
-- | Swap foreground and background colors, inconsistent emulation
invert :: Builder ()
invert = [Word8] -> Builder ()
sgr [Word8
7]
invertOff :: Builder ()
invertOff = [Word8] -> Builder ()
sgr [Word8
27]

-- | Colorized some text
color :: AnsiColor -> B.Builder () -> B.Builder ()
color :: AnsiColor -> Builder () -> Builder ()
color AnsiColor
c Builder ()
t = do
    AnsiColor -> Builder ()
setForeground AnsiColor
c
    Builder ()
t
    Builder ()
setDefaultForeground

-- | Colorized some text with background color
color' :: AnsiColor -> AnsiColor -> B.Builder () -> B.Builder ()
color' :: AnsiColor -> AnsiColor -> Builder () -> Builder ()
color' AnsiColor
c1 AnsiColor
c2 Builder ()
t = do
    AnsiColor -> Builder ()
setForeground AnsiColor
c1
    AnsiColor -> Builder ()
setBackground AnsiColor
c2
    Builder ()
t
    Builder ()
setDefaultForeground
    Builder ()
setDefaultBackground

-- | Colorized some text
palette :: PaletteColor -> B.Builder () -> B.Builder ()
palette :: Word8 -> Builder () -> Builder ()
palette Word8
c Builder ()
t = do
    Word8 -> Builder ()
setPaletteForeground Word8
c
    Builder ()
t
    Builder ()
setDefaultForeground

-- | Colorized some text with background color
palette' :: PaletteColor -> PaletteColor -> B.Builder () -> B.Builder ()
palette' :: Word8 -> Word8 -> Builder () -> Builder ()
palette' Word8
c1 Word8
c2 Builder ()
t = do
    Word8 -> Builder ()
setPaletteForeground Word8
c1
    Word8 -> Builder ()
setPaletteBackground Word8
c2
    Builder ()
t
    Builder ()
setDefaultForeground
    Builder ()
setDefaultBackground

-- | Colorized some text
rgb :: RGBColor -> B.Builder () -> B.Builder ()
rgb :: RGBColor -> Builder () -> Builder ()
rgb RGBColor
c Builder ()
t = do
    RGBColor -> Builder ()
setRGBForeground RGBColor
c
    Builder ()
t
    Builder ()
setDefaultForeground

-- | Colorized some text with background color
rgb' :: RGBColor -> RGBColor -> B.Builder () -> B.Builder ()
rgb' :: RGBColor -> RGBColor -> Builder () -> Builder ()
rgb' RGBColor
c1 RGBColor
c2 Builder ()
t = do
    RGBColor -> Builder ()
setRGBForeground RGBColor
c1
    RGBColor -> Builder ()
setRGBBackground RGBColor
c2
    Builder ()
t
    Builder ()
setDefaultForeground
    Builder ()
setDefaultBackground

setForeground, setBrightForeground, setBackground, setBrightBackground :: AnsiColor -> B.Builder ()
setForeground :: AnsiColor -> Builder ()
setForeground AnsiColor
c       = [Word8] -> Builder ()
sgr [Word8
30 Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
+ AnsiColor -> Word8
colorToCode AnsiColor
c]
setBrightForeground :: AnsiColor -> Builder ()
setBrightForeground AnsiColor
c = [Word8] -> Builder ()
sgr [Word8
90 Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
+ AnsiColor -> Word8
colorToCode AnsiColor
c]
setBackground :: AnsiColor -> Builder ()
setBackground AnsiColor
c       = [Word8] -> Builder ()
sgr [Word8
40 Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
+ AnsiColor -> Word8
colorToCode AnsiColor
c]
setBrightBackground :: AnsiColor -> Builder ()
setBrightBackground AnsiColor
c = [Word8] -> Builder ()
sgr [Word8
100 Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
+ AnsiColor -> Word8
colorToCode AnsiColor
c]

setPaletteForeground, setPaletteBackground :: PaletteColor -> B.Builder ()
setPaletteForeground :: Word8 -> Builder ()
setPaletteForeground Word8
index = [Word8] -> Builder ()
sgr [Word8
38, Word8
5, Word8
index]
setPaletteBackground :: Word8 -> Builder ()
setPaletteBackground Word8
index = [Word8] -> Builder ()
sgr [Word8
48, Word8
5, Word8
index]

setRGBForeground, setRGBBackground :: RGBColor -> B.Builder ()
setRGBForeground :: RGBColor -> Builder ()
setRGBForeground (Word8
r,Word8
g,Word8
b) = [Word8] -> Builder ()
sgr [Word8
38, Word8
2, Word8
r, Word8
g, Word8
b]
setRGBBackground :: RGBColor -> Builder ()
setRGBBackground (Word8
r,Word8
g,Word8
b) = [Word8] -> Builder ()
sgr [Word8
48, Word8
2, Word8
r, Word8
g, Word8
b]

setDefaultForeground, setDefaultBackground :: B.Builder ()
setDefaultForeground :: Builder ()
setDefaultForeground = [Word8] -> Builder ()
sgr [Word8
39]
setDefaultBackground :: Builder ()
setDefaultBackground = [Word8] -> Builder ()
sgr [Word8
49]

-- | ANSI's eight standard colors
data AnsiColor = Black
               | Red
               | Green
               | Yellow
               | Blue
               | Magenta
               | Cyan
               | White
        deriving (AnsiColor -> AnsiColor -> Bool
(AnsiColor -> AnsiColor -> Bool)
-> (AnsiColor -> AnsiColor -> Bool) -> Eq AnsiColor
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: AnsiColor -> AnsiColor -> Bool
$c/= :: AnsiColor -> AnsiColor -> Bool
== :: AnsiColor -> AnsiColor -> Bool
$c== :: AnsiColor -> AnsiColor -> Bool
Eq, Eq AnsiColor
Eq AnsiColor
-> (AnsiColor -> AnsiColor -> Ordering)
-> (AnsiColor -> AnsiColor -> Bool)
-> (AnsiColor -> AnsiColor -> Bool)
-> (AnsiColor -> AnsiColor -> Bool)
-> (AnsiColor -> AnsiColor -> Bool)
-> (AnsiColor -> AnsiColor -> AnsiColor)
-> (AnsiColor -> AnsiColor -> AnsiColor)
-> Ord AnsiColor
AnsiColor -> AnsiColor -> Bool
AnsiColor -> AnsiColor -> Ordering
AnsiColor -> AnsiColor -> AnsiColor
forall a.
Eq a
-> (a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
min :: AnsiColor -> AnsiColor -> AnsiColor
$cmin :: AnsiColor -> AnsiColor -> AnsiColor
max :: AnsiColor -> AnsiColor -> AnsiColor
$cmax :: AnsiColor -> AnsiColor -> AnsiColor
>= :: AnsiColor -> AnsiColor -> Bool
$c>= :: AnsiColor -> AnsiColor -> Bool
> :: AnsiColor -> AnsiColor -> Bool
$c> :: AnsiColor -> AnsiColor -> Bool
<= :: AnsiColor -> AnsiColor -> Bool
$c<= :: AnsiColor -> AnsiColor -> Bool
< :: AnsiColor -> AnsiColor -> Bool
$c< :: AnsiColor -> AnsiColor -> Bool
compare :: AnsiColor -> AnsiColor -> Ordering
$ccompare :: AnsiColor -> AnsiColor -> Ordering
$cp1Ord :: Eq AnsiColor
Ord, AnsiColor
AnsiColor -> AnsiColor -> Bounded AnsiColor
forall a. a -> a -> Bounded a
maxBound :: AnsiColor
$cmaxBound :: AnsiColor
minBound :: AnsiColor
$cminBound :: AnsiColor
Bounded, Int -> AnsiColor
AnsiColor -> Int
AnsiColor -> [AnsiColor]
AnsiColor -> AnsiColor
AnsiColor -> AnsiColor -> [AnsiColor]
AnsiColor -> AnsiColor -> AnsiColor -> [AnsiColor]
(AnsiColor -> AnsiColor)
-> (AnsiColor -> AnsiColor)
-> (Int -> AnsiColor)
-> (AnsiColor -> Int)
-> (AnsiColor -> [AnsiColor])
-> (AnsiColor -> AnsiColor -> [AnsiColor])
-> (AnsiColor -> AnsiColor -> [AnsiColor])
-> (AnsiColor -> AnsiColor -> AnsiColor -> [AnsiColor])
-> Enum AnsiColor
forall a.
(a -> a)
-> (a -> a)
-> (Int -> a)
-> (a -> Int)
-> (a -> [a])
-> (a -> a -> [a])
-> (a -> a -> [a])
-> (a -> a -> a -> [a])
-> Enum a
enumFromThenTo :: AnsiColor -> AnsiColor -> AnsiColor -> [AnsiColor]
$cenumFromThenTo :: AnsiColor -> AnsiColor -> AnsiColor -> [AnsiColor]
enumFromTo :: AnsiColor -> AnsiColor -> [AnsiColor]
$cenumFromTo :: AnsiColor -> AnsiColor -> [AnsiColor]
enumFromThen :: AnsiColor -> AnsiColor -> [AnsiColor]
$cenumFromThen :: AnsiColor -> AnsiColor -> [AnsiColor]
enumFrom :: AnsiColor -> [AnsiColor]
$cenumFrom :: AnsiColor -> [AnsiColor]
fromEnum :: AnsiColor -> Int
$cfromEnum :: AnsiColor -> Int
toEnum :: Int -> AnsiColor
$ctoEnum :: Int -> AnsiColor
pred :: AnsiColor -> AnsiColor
$cpred :: AnsiColor -> AnsiColor
succ :: AnsiColor -> AnsiColor
$csucc :: AnsiColor -> AnsiColor
Enum, Int -> AnsiColor -> ShowS
[AnsiColor] -> ShowS
AnsiColor -> String
(Int -> AnsiColor -> ShowS)
-> (AnsiColor -> String)
-> ([AnsiColor] -> ShowS)
-> Show AnsiColor
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [AnsiColor] -> ShowS
$cshowList :: [AnsiColor] -> ShowS
show :: AnsiColor -> String
$cshow :: AnsiColor -> String
showsPrec :: Int -> AnsiColor -> ShowS
$cshowsPrec :: Int -> AnsiColor -> ShowS
Show, ReadPrec [AnsiColor]
ReadPrec AnsiColor
Int -> ReadS AnsiColor
ReadS [AnsiColor]
(Int -> ReadS AnsiColor)
-> ReadS [AnsiColor]
-> ReadPrec AnsiColor
-> ReadPrec [AnsiColor]
-> Read AnsiColor
forall a.
(Int -> ReadS a)
-> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
readListPrec :: ReadPrec [AnsiColor]
$creadListPrec :: ReadPrec [AnsiColor]
readPrec :: ReadPrec AnsiColor
$creadPrec :: ReadPrec AnsiColor
readList :: ReadS [AnsiColor]
$creadList :: ReadS [AnsiColor]
readsPrec :: Int -> ReadS AnsiColor
$creadsPrec :: Int -> ReadS AnsiColor
Read, (forall x. AnsiColor -> Rep AnsiColor x)
-> (forall x. Rep AnsiColor x -> AnsiColor) -> Generic AnsiColor
forall x. Rep AnsiColor x -> AnsiColor
forall x. AnsiColor -> Rep AnsiColor x
forall a.
(forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
$cto :: forall x. Rep AnsiColor x -> AnsiColor
$cfrom :: forall x. AnsiColor -> Rep AnsiColor x
Generic)
        deriving anyclass Int -> AnsiColor -> Builder ()
(Int -> AnsiColor -> Builder ()) -> Print AnsiColor
forall a. (Int -> a -> Builder ()) -> Print a
toUTF8BuilderP :: Int -> AnsiColor -> Builder ()
$ctoUTF8BuilderP :: Int -> AnsiColor -> Builder ()
T.Print

colorToCode :: AnsiColor -> Word8
colorToCode :: AnsiColor -> Word8
colorToCode AnsiColor
c = case AnsiColor
c of
    AnsiColor
Black   -> Word8
0
    AnsiColor
Red     -> Word8
1
    AnsiColor
Green   -> Word8
2
    AnsiColor
Yellow  -> Word8
3
    AnsiColor
Blue    -> Word8
4
    AnsiColor
Magenta -> Word8
5
    AnsiColor
Cyan    -> Word8
6
    AnsiColor
White   -> Word8
7

-- | 8-bit palette color, see https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit
type PaletteColor = Word8

-- | 24-bit RGB color
type RGBColor = (Word8, Word8, Word8)