String#each_match, kind of like String#scan but returning MatchData instead of the simple match. It takes a block as well!

string_each_match.rb

class String
  def each_match(regex)
    result = []
    position = 0
    
    while match_data = regex.match(self, position) do
      result << if block_given? then yield(match_data) else match_data end
      position = match_data.end(match_data.size - 1)
    end
    
    result
  end
end

'jojo'.each_match(/./) do |match|
  [match.pre_match, match[0], match.post_match].join('*')
end
# => ["*j*ojo", "j*o*jo", "jo*j*o", "joj*o*"]