How does one create a recursive lexer?

In OS X, how can one create a custom RSS feed (by keyword) that will show up in their notification center?

• I am overwhelmed by the number of applications that allow me to do either one or the other (search by keyword or create an RSS feed that will show up in notification center), but seemingly not both.I am overwhelmed by the number of applications that allow me to do either one or the other (search by keyword or create an RSS feed that will show up in notification center), but seemingly not both.     I am overwhelmed by the number of applications that allow me to do either one or the other (search by keyword or create an RSS feed that will show up in notification center), but seemingly not both. Link to Questions, Topics, Blogs and People

• Answer:

  Use the'Monotony' feed reader http://www.timschroeder.net/monotony/