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

If using ruby >=1.9 and the named captures, you could:

class String 
  def scan2(regexp2_str, placeholders = {})
    return regexp2_str.to_re(placeholders).match(self)
  end

  def to_re(placeholders = {})
    re2 = self.dup
    separator = placeholders.delete(:SEPARATOR) || '' #Returns and removes separator if :SEPARATOR is set.
    #Search for the pattern placeholders and replace them with the regex
    placeholders.each do |placeholder, regex|
      re2.sub!(separator + placeholder.to_s + separator, "(?<#{placeholder}>#{regex})")
    end    
    return Regexp.new(re2, Regexp::MULTILINE)    #Returns regex using named captures.
  end
end

Usage (ruby >=1.9):

> "1234:Kalle".scan2("num4:name", num4:'\d{4}', name:'\w+')
=> #

or

> re="num4:name".to_re(num4:'\d{4}', name:'\w+')
=> /(?\d{4}):(?\w+)/m

> m=re.match("1234:Kalle")
=> #
> m[:num4]
=> "1234"
> m[:name]
=> "Kalle"

Using the separator option:

> "1234:Kalle".scan2("#num4#:#name#", SEPARATOR:'#', num4:'\d{4}', name:'\w+')
=> #