add a visit link command

gem300.rkt

@@ -39,7 +39,10 @@
   (iter 10)
   (newline)
   (let ([remaining (pipe-content-length document-buffer)])
-     (printf "~a bytes remaining\n" remaining)))
+    (printf "~a bytes remaining\n" remaining)))
+
+(define (visit-cmd line)
+  (go-cmd (gmi:match-link document (string->number line))))
 
 (define (repl)
   (display "G-300 > ")
@@ -55,6 +58,10 @@
       ;; go command
       [(or (string=? (cadr matches) "go")
            (string=? (cadr matches) "g"))
-       (go-cmd (caddr matches))]))
+       (go-cmd (caddr matches))]
+
+      ;; visit link command
+      [(andmap char-numeric? (string->list (cadr matches)))
+       (visit-cmd (cadr matches))]))
 
   (repl))