handle relative links and unspecified schemes

gem300.rkt

@@ -3,6 +3,8 @@
 (require (prefix-in net: "net.rkt")
          (prefix-in gmi: "gmi.rkt"))
 
+(require net/url-string)
+
 ;; global state variable which will be an input port containing the
 ;; rendered out gemtext document as it shall be shown to the user
 (define document-buffer null)
@@ -10,8 +12,15 @@
 ;; global state which will be the document structure, before rendering
 (define document null)
 
+;; global state for the url of the currently visited document
+(define current-url null)
+
 (define (go-cmd url)
   (if (non-empty-string? url)
+      (let ()
+        (when (not (string-contains? url "://"))
+          (set! url (string-append "gemini://" url)))
+
         (let-values ([(status meta c-in) (net:get url)])
           (let-values ([(doc) (gmi:parse (port->lines c-in))]
                        [(db-in db-out) (make-pipe #f)])
@@ -22,10 +31,12 @@
             (parameterize ([current-output-port db-out])
               (gmi:render doc))
 
+            (set! current-url url)
+
             (let ([remaining (pipe-content-length db-in)])
               (printf "document retrieved. ~a bytes\n" remaining))
 
-          (next-cmd)))
+            (next-cmd))))
 
       (displayln "go where?")))
 
@@ -43,7 +54,11 @@
     (printf "~a bytes remaining\n" remaining)))
 
 (define (visit-cmd line)
-  (go-cmd (gmi:match-link document (string->number line))))
+  (define url (gmi:match-link document (string->number line)))
+  (set! url
+        (url->string (combine-url/relative (string->url current-url)
+                                           url)))
+  (go-cmd url))
 
 (define (repl)
   (display "G-300 > ")