From: Dominik Bathon <dbatml@...>
Date: 2005-04-22T10:50:38+09:00
Subject: Re: Linear complete variation of MatchData#to_a, possible?

On Wed, 20 Apr 2005 22:59:33 +0200, Trans <transfire@gmail.com> wrote:

> Amazing Pit Capitain! Your hunch was right on the money. Not only was
> your suggestion key to the solution, but the output was just as you
> expected. Here's the solution I found. It's not all that elegant, but
> it appears to work okay. I am certain there are much better solutions
> to be had, so if anyone has one to offer...

Here is my recursive version:

class MatchData

    def matchtree(index=0)
       ret=[]
       b, e=self.begin(index), self.end(index)
       while (index+=1)<=length
          if index==length || (bi=self.begin(index))>=e
             # we are finished, if something is left, then add it
             ret << string[b, e-b] if e>b
             break
          else
             if bi>=b
                ret << string[b, bi-b] if bi>b
                ret << matchtree(index)
                b=self.end(index)
             end
          end
       end
       ret
    end

    def matchset
       [pre_match, matchtree, post_match]
    end

end

md = /(bb)(cc(dd))(ee)/.match "XXaabbccddeeffXX"
p md.to_a
p md.matchset
md.length.times { |i| p md.matchtree(i) }


Output:
["bbccddee", "bb", "ccdd", "dd", "ee"]
["XXaa", [["bb"], ["cc", ["dd"]], ["ee"]], "ffXX"]
[["bb"], ["cc", ["dd"]], ["ee"]]
["bb"]
["cc", ["dd"]]
["dd"]
["ee"]

Btw. your version seems to have a little problem:
> #=> ["XXaa", [["bb"], ["cc", ["dd"]], "ee"], "ffXX"]
There are no brackets around the "ee".

Dominik