return ErrorToken, fmt.Sprintf("error expected: keyword found '%s'", buffer)
	}
	return lastScannedItem.tok, lastScannedItem.literal
}

// skipWhiteSpaces consumes all blank characters
// returning the first non blank character
func (l *Lexer) skipWhiteSpaces(ch byte) byte {
	for {
		if !isWhitespace(ch) {
			return ch
		}
		ch = l.read()
	}
}

// Lex returns a pair of Token and the literal