(use intarweb uri-common)

(write-request
  (make-request
    method: 'GET
    uri: (uri-reference "https://caolan.org/index.html")
    port: (current-output-port)))


;; result
;; GET https://caolan.org/index.html HTTP/1.1

;; should this be?
;; GET /index.html HTTP/1.1