assign_route_options

# File actionpack/lib/action_controller/routing/builder.rb, line 92
      def assign_route_options(segments, defaults, requirements)
        route_requirements = {} # Requirements that do not belong to a segment

        segment_named = Proc.new do |key|
          segments.detect { |segment| segment.key == key if segment.respond_to?(:key) }
        end

        requirements.each do |key, requirement|
          segment = segment_named[key]
          if segment
            raise TypeError, "#{key}: requirements on a path segment must be regular expressions" unless requirement.is_a?(Regexp)
            if requirement.source =~ %r{\A(\\A|\^)|(\\Z|\\z|\$)\Z}
              raise ArgumentError, "Regexp anchor characters are not allowed in routing requirements: #{requirement.inspect}"
            end
            if multiline_regexp?(requirement)
              raise ArgumentError, "Regexp multiline option not allowed in routing requirements: #{requirement.inspect}"
            end
            segment.regexp = requirement
          else
            route_requirements[key] = requirement
          end
        end

        defaults.each do |key, default|
          segment = segment_named[key]
          raise ArgumentError, "#{key}: No matching segment exists; cannot assign default" unless segment
          segment.is_optional = true
          segment.default = default.to_param if default
        end

        assign_default_route_options(segments)
        ensure_required_segments(segments)
        route_requirements
      end