evalExpr :: LispEnv s -> T.Text -> ST s (ThrowsError (LispVal s))
evalExpr env expr =
    case readExpr expr of
        Left err  -> return $ Left err
        Right val -> eval env val
evalExpr :: LispEnv s -> T.Text -> ST s (ThrowsError (LispVal s))
evalExpr env expr =
    case readExpr expr of
        Left err  -> return $ Left err
        Right val -> eval env val
evalExpr env expr =
    case readExpr expr of
        Left err  -> return $ Left err
        Right val -> eval env val