standardize on storing urls as url structs internally instead of as strings

gmi.rkt

@@ -3,9 +3,11 @@
 (provide (contract-out
           [render (-> document? void?)]
           [parse (-> (listof string?) document?)]
-          [match-link (-> document? integer? (or/c string? #f))]
+          [match-link (-> document? integer? (or/c url? #f))]
           [struct document ((items (listof (or/c text? link? pre?))))]))
 
+(require net/url-string)
+
 ;; a gemtext document is represented as a list of structs, a struct
 ;; for each type of item in a document.
 (struct document (items))
@@ -22,7 +24,7 @@
   (let ([split (string-split (substring line 2))])
     (if (empty? split)
         (text line)
-        (link (car split)
+        (link (string->url (car split))
               (if (>= (length split) 2)
                   (string-join (cdr split))
                   (car split))

net.rkt

@@ -1,21 +1,17 @@
 #lang racket
 
-(provide request)
+(provide (contract-out
+          [request (-> url? (values integer? string? input-port?))]))
 
 (require openssl)
 (require net/url-string)
 
-;; sends a request to a gemini server, and returns the status, header,
-;; and the input port for the rest of the body.
-;; this procedure will fail if the response is malformed, however, it
-;; is not up to it to validate the contents of the response.
-(define (request url-str)
-  (define url (string->url url-str))
+(define (request url)
   (define-values (c-in c-out)
     (ssl-connect (url-host url)
                  (or (url-port url) 1965)))
 
-  (write-string url-str c-out)
+  (write-string (url->string url) c-out)
   (write-string "\r\n" c-out)
 
   (define-values (status header)