class Sinatra::Base

def process_route(pattern, keys, conditions)
  @original_params ||= @params
  if match = pattern.match(@request.route)
    values = match.captures.to_a
    params =
      if keys.any?
        keys.zip(values).inject({}) do |hash,(k,v)|
          if k == 'splat'
            (hash[k] ||= []) << v
          else
            hash[k] = v
          end
          hash
        end
      elsif values.any?
        {'captures' => values}
      else
        {}
      end
    @params = @original_params.merge(params)
    @block_params = values
    catch(:pass) do
      conditions.each { |cond|
        throw :pass if instance_eval(&cond) == false }
      yield
    end
  end
ensure
  @params = @original_params
end