{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleContexts #-}

module Language.SimpleShell.Parser
  ( lexeme
  , symbol
  , commentFirstChars
  )
where


import Control.Monad (void)
import Data.Text (Text)
import Text.Megaparsec (MonadParsec)
import Text.Megaparsec.Char (space1)
import qualified Text.Megaparsec.Char.Lexer as L
  ( lexeme
  , symbol
  , space
  , skipLineComment
  , skipBlockComment
  )


-- Must be kept in sync with 'commentFirstChars'.
sc :: (MonadParsec e Text m) => m ()
sc = L.space
  space1
  (L.skipLineComment "//")
  (L.skipBlockComment "/*" "*/")

-- | List of all characters that may start a comment.
commentFirstChars :: [Char]
commentFirstChars = "/"

lexeme :: (MonadParsec e Text m) => m a -> m a
lexeme = L.lexeme sc

symbol :: (MonadParsec e Text m) => Text -> m ()
symbol = void . L.symbol sc