Start ordered lists using the initial numbers from markdown lists

lib/marked.js

@@ -164,7 +164,8 @@ Lexer.prototype.token = function(src, top) {
       space,
       i,
       tag,
-      l;
+      l,
+      isordered;
 
   while (src) {
     // newline
@@ -279,10 +280,12 @@ Lexer.prototype.token = function(src, top) {
     if (cap = this.rules.list.exec(src)) {
       src = src.substring(cap[0].length);
       bull = cap[2];
+      isordered = bull.length > 1;
 
       this.tokens.push({
         type: 'list_start',
-        ordered: bull.length > 1
+        ordered: isordered,
+        start: isordered ? +bull : ''
       });
 
       // Get each top-level item.
@@ -836,9 +839,10 @@ Renderer.prototype.hr = function() {
   return this.options.xhtml ? '<hr/>\n' : '<hr>\n';
 };
 
-Renderer.prototype.list = function(body, ordered) {
-  var type = ordered ? 'ol' : 'ul';
-  return '<' + type + '>\n' + body + '</' + type + '>\n';
+Renderer.prototype.list = function(body, ordered, start) {
+  var type = ordered ? 'ol' : 'ul',
+      startatt = (ordered && start !== 1) ? (' start="' + start + '"') : '';
+  return '<' + type + startatt + '>\n' + body + '</' + type + '>\n';
 };
 
 Renderer.prototype.listitem = function(text) {
@@ -1099,13 +1103,14 @@ Parser.prototype.tok = function() {
     }
     case 'list_start': {
       body = '';
-      var ordered = this.token.ordered;
+      var ordered = this.token.ordered,
+          start = this.token.start;
 
       while (this.next().type !== 'list_end') {
         body += this.tok();
       }
 
-      return this.renderer.list(body, ordered);
+      return this.renderer.list(body, ordered, start);
     }
     case 'list_item_start': {
       body = '';

test/integration/marked-spec.js

@@ -3,3 +3,16 @@ var marked = require('../../marked.min.js');
 it('should run the test', function () {
   expect(marked('Hello World!')).toBe('<p>Hello World!</p>\n');
 });
+
+// http://spec.commonmark.org/0.28/#example-230
+it('should start an ordered list at 0 when requested', function () {
+  expect(
+    marked('0. ok')).
+    toBe("<ol start=\"0\">\n<li>ok</li>\n</ol>\n")
+});
+
+// http://spec.commonmark.org/0.28/#example-234
+it('indents code within an explicitly-started ordered list', function () {
+  expect(marked("  10.  foo\n\n           bar")).
+  toBe("<ol start=\"10\">\n<li><p>foo</p>\n<pre><code>bar\n</code></pre></li>\n</ol>\n");
+});

test/original/ordered_and_unordered_lists.html

@@ -146,3 +146,19 @@ <h2>Nested</h2>
 
 <p>that</p></li>
 </ul>
+
+
+<p>Ordered lists start from initial number:</p>
+
+<ol start="3">
+<li>Three</li>
+<li>Four</li>
+</ol>
+
+
+<p>Ordered lists start from initial zero:</p>
+
+<ol start="0">
+<li>Zero</li>
+<li>One</li>
+</ol>

test/original/ordered_and_unordered_lists.md

@@ -88,7 +88,7 @@ Multiple paragraphs:
 
 	Item 2. graf two. The quick brown fox jumped over the lazy dog's
 	back.
-	
+
 2.	Item 2.
 
 3.	Item 3.
@@ -129,3 +129,13 @@ This was an error in Markdown 1.0.1:
 	*	sub
 
 	that
+
+Ordered lists start from initial number:
+
+3. Three
+1. Four
+
+Ordered lists start from initial zero:
+
+0. Zero
+1. One