The Grepper class greps through files, and returns a result set of Grepper::Result objects. Each Result object represents the matches found in a single file. The Result contains a set of Grepper::Match objects. Each Match object represents a line (the line that matched) and before- and after-context arrays. If no before or after lines were requested, those context values will be nil. To use, you prepare a Grepper object; call <tt>run</tt> on it; and walk through the result set.