Highlighter.hs

module Highlighter.Highlighter where

import Data.Text
import Common
import System.Console.ANSI (Color(..), Underlining(..), SGR(..), setSGRCode)
import DiffRender.DiffRender

-- Mostly for use with highlighting and not actual token parsing.
-- This represent any tokens we want to show in editors with highlighting.
class Highlightable a where
  getTokenLoc :: a -> Location
  highlight :: (StyledText, Maybe a) -> StyledText
  pairWithTokens :: [a] -> Int -> Text -> ([(Text, Maybe a)], [a])
  -- ^ Associate token type with their text sources
  -- First arg is stack of tokens at current location
  -- Second arg is the text offset at current location
  -- Third arg is the text at the current location
  --
  -- This is so that in an editor, a line of text can break at somewhere in the
  -- middle of a single token. So an editor cannot display tokenwise without more
  -- complex tracking of current offset in source text.

instance Highlightable Text where
  highlight (x, _) = x
  pairWithTokens _ _ t = ([(t, Nothing)], [])
  getTokenLoc = error "No token location for text"

underlineText :: Text -> Text
underlineText t = let
  startCode = (setSGRCode [SetUnderlining SingleUnderline])
  endCode = setSGRCode []
  in (pack startCode) <> t <> (pack endCode)

colorText :: Color -> Color -> Text -> StyledText
colorText fg bg t = StyledText (FgBg fg bg) [Plain t]

colorTextFg :: Color -> Text -> StyledText
colorTextFg fg t = StyledText (Fg fg) [Plain t]