commit 721a55a9e57cebcde535bfaa77e3bbaae956d55b
from: Omar Polo <op@omarpolo.com>
date: Mon Jan 17 10:05:04 2022 UTC

handle non-closed verbatim blocks and nil-ify empty labels

The idea behind the ``` marker is to toggle the preformatted bit on
and off, so it's not strictly speaking a "verbatim block", even if
it's easier to manage it that way.

However, don't throw generic errors like that, and handle EOF without
a closing ``` marker.  While here, if label is the empty string, use
nil.

commit - 385d8c27124fbdf6686d98559ae01dc9c6a8acd0
commit + 721a55a9e57cebcde535bfaa77e3bbaae956d55b
blob - 89f55326edea41032c0eee14bd565226cf770ab9
blob + 124e85332fac9df40785f67e29e174aea69cc734
--- gemtext.lisp
+++ gemtext.lisp
@@ -92,11 +92,11 @@ Can be a programming language name or alternative text
                 (loop with label = (subseq line 3)
                       with content = nil
                       for line = (read-line in nil)
-                      unless line
-                        do (error "non-closed verbatim")
-                      when (markerp line)
+                      when (or (not line)
+                               (markerp line))
                         return (make-instance 'verbatim
-                                              :alt label
+                                              :alt (unless (string-equal label "")
+                                                     label)
                                               :text (format nil "~{~A~%~^~}"
                                                             (nreverse content)))
                       do (push line content))