Regex with named capture groups getting all matches in Ruby

Question

I have a string:

s=\"123--abc,123--abc,123--abc\"

I tried using Ruby 1.9\'s new feature \"named groups\" to fetch all named group info:

Answer 1

I needed something similar recently. This should work like String#scan, but return an array of MatchData objects instead.

class String
  # This method will return an array of MatchData's rather than the
  # array of strings returned by the vanilla `scan`.
  def match_all(regex)
    match_str = self
    match_datas = []
    while match_str.length > 0 do 
      md = match_str.match(regex)
      break unless md
      match_datas << md
      match_str = md.post_match
    end
    return match_datas
  end
end

Running your sample data in the REPL results in the following:

> "123--abc,123--abc,123--abc".match_all(/(?\d*)--(?[a-z]*)/)
=> [#,
    #,
    #]

You may also find my test code useful:

describe String do
  describe :match_all do
    it "it works like scan, but uses MatchData objects instead of arrays and strings" do
      mds = "ABC-123, DEF-456, GHI-098".match_all(/(?[A-Z]+)-(?[0-9]+)/)
      mds[0][:word].should   == "ABC"
      mds[0][:number].should == "123"
      mds[1][:word].should   == "DEF"
      mds[1][:number].should == "456"
      mds[2][:word].should   == "GHI"
      mds[2][:number].should == "098"
    end
  end
end