gistfile1.txt

def extract_regex(string)
  string.scan(/([a-z_]+):(?:\/|%r\{)((?:(?:\\\/)|[^\/])+)(?:\/|\})/).inject({}) do |hash, match|
    hash.merge match.first.to_sym => Regexp.new(match.last)
  end
end

test_string = 'this is a a:/regular/ expression b:/with a \/ in it/ and some c:%r{other stuff}'
expected = {:a => /regular/, :b => /with a \/ in it/, :c => /other stuff/}
actual = extract_regex(test_string)

if expected == actual
  puts "success"
else
  puts "fail (expected #{expected.inspect}, got #{actual.inspect})"
end