module Sprockets::HTTPUtils

def find_q_matches(q_values, available, &matcher)

Returns Array of matched Strings from available Array or [].

Adapted from Rack::Utils#q_values.

Internal: Find all qvalue matches from an Array of available options. 
def find_q_matches(q_values, available, &matcher)
  matcher ||= lambda { |a, b| a == b }
  matches = []
  case q_values
  when Array
  when String
    q_values = parse_q_values(q_values)
  when NilClass
    q_values = []
  else
    raise TypeError, "unknown q_values type: #{q_values.class}"
  end
  q_values.each do |accepted, quality|
    if match = available.find { |option| matcher.call(option, accepted) }
      matches << [match, quality]
    end
  end
  matches.sort_by { |match, quality| -quality }.map { |match, quality| match }
end