module Parser.Util where

import AST (Expr)
import Text.Megaparsec
import Data.Void (Void)
import Data.Text (Text)
import Control.Monad.Reader (Reader)

type Parser = ParsecT Void Text (Reader ParserData)

newtype ParserData = ParserData {
  exprParser :: Parser (Expr SourceRange)
}

-- | Specifies start and end positions of a parsed expression.
type SourceRange = (SourcePos, SourcePos)

-- | Adds the source range to a parser.
withSourceRange :: (MonadParsec e s m, TraversableStream s) => m (SourceRange -> a) -> m a
withSourceRange parser = flip curry <$> getSourcePos <*> parser <*> getSourcePos