This is the first of a two part article describing the use of the boost::spirit parser framework. Spirit is the best fully object oriented parser that I have seen, allowing a user to rapidly created fully functional parsers using highly object oriented code. This first article is intended to introduce a programmer to writing enough code to successfully parse some simple input. I will not deal with any semantic actions. The next article will actually plumb in some semantic actions and create a fully working modular arithmetic calculator.