class Raabro::Input

def match(str_or_regex)
  if str_or_regex.is_a?(Regexp)
    m = @string[@offset..-1].match(str_or_regex)
    m && (m.offset(0).first == 0) ? m[0].length : false
  else # String or whatever responds to #to_s
    s = str_or_regex.to_s
    l = s.length
    @string[@offset, l] == s ? l : false
  end
end