Is there a function like String#scan, but returning array of MatchDatas?

Question

I need a function to return all matches of a regexp in a string and positions at which the matches are found (I want to highlight matches in the string).

There is String#match that returns MatchData, but only for the first match.

Is there a better way to do this than something like

matches = []
begin
  match = str.match(regexp)
  break unless match
  matches << match
  str = str[match.end(0)..-1]
  retry
end

Answer 1

If you just need to iterate over the MatchData objects you can use Regexp.last_match in the scan-block, like:

string.scan(regex) do
  match_data = Regexp.last_match
  do_something_with(match_data)
end

If you really need an array, you can use:

require 'enumerator' # Only needed for ruby 1.8.6
string.enum_for(:scan, regex).map { Regexp.last_match }

Answer 2

Do you really need the position or is it enough to replace the matches on the fly?

s="I'mma let you finish but Beyonce had one of the best music videos of all time!"
s.gsub(/(Beyonce|best)/, '<b>\1</b>')

=> "I'mma let you finish but Beyonce had one of the best music videos of all time!"

Answer 3

I think at least you can enhance your code a bit:

matches = []
while(match = str.match(regexp)) 
  matches << match
  str = match.post_match
end