The source linked to above includes an illustration of how to use the combinators to build a pattern-matching function for C's floating-point numbers. Specifically, it implements:
"-"?(([0-9]+(\\.[0-9]+)?)|(\\.[0-9]+))([eE][+-]?[0-9]+)?
I've added a lot of explanatory comments, but it's worth noting that without them, the entire thing fits on a single page. Although I came up with this technique on my own and originally didn't know the technique had a name, I was later informed that it is an example of parser combinators. I'm calling this particular manifestation lexer combinators because in this case that term seems more accurate.