assign numbers to links in a document

gem300.rkt

@@ -4,21 +4,22 @@
 (require net/url)
 
 (struct text (str))
-(struct link (url str))
+(struct link (url str ord))
 (struct preformatted (str))
 
-(define (parse-url line)
+(define (parse-url line link-#)
   (let ([split (string-split (substring line 2))])
     (if (empty? split)
         (text line)
         (link (car split)
               (if (>= (length split) 2)
                   (string-join (cdr split))
-                  (car split))))))
+                  (car split))
+              link-#))))
 
 
 (define (gemtext-parse lines)
-  (define (iter document lines state)
+  (define (iter document lines state link-#)
     ;; when there are no more lines, we have finished parsing.
     (if (empty? lines)
         ;; consing inherently makes everything backwards
@@ -39,7 +40,8 @@
            (iter (cons (preformatted (reverse (preformatted-str (car document))))
                        (cdr document))
                  (cdr lines)
-                 'normal)]
+                 'normal
+                 link-#)]
 
           ;; add line to most recent preformat block
           [(symbol=? 'preformatted state)
@@ -51,31 +53,37 @@
                                            (preformatted-str (car document))))
                        (cdr document))
                  (cdr lines)
-                 'preformatted)]
+                 'preformatted
+                 link-#)]
 
           ;; rest of this is normal mode
 
           ;; link lines
           [(string-prefix? (car lines) "=>")
-           (iter (cons (parse-url (car lines))
-                       document)
+           (let ([parsed (parse-url (car lines) link-#)])
+                 (iter (cons parsed document)
                        (cdr lines)
-                 'normal)]
+                       'normal
+                       (if (link? parsed)
+                           (add1 link-#)
+                           link-#)))]
 
           ;; preformatting toggle lines
           [(string-prefix? (car lines) "```")
            ;; add preformatted block to document and toggle mode
            (iter (cons (preformatted (list)) document)
                  (cdr lines)
-                 'preformatted)]
+                 'preformatted
+                 link-#)]
 
           [else
            (iter (cons (text (car lines))
                        document)
                  (cdr lines)
-                 'normal)])))
+                 'normal
+                 link-#)])))
 
-  (iter (list) lines 'normal))
+  (iter (list) lines 'normal 1))
 
 (define (request url-str)
   (define url (string->url url-str))
@@ -157,7 +165,7 @@
                                (preformatted-str line))]
 
                     [(link? line)
-                     (printf "[#] ~a\n" (link-str line))]))
+                     (printf "[~a] ~a\n" (link-ord line) (link-str line))]))
             document))
 
 (define commands