update message generator

how-to/messageLists.rst

@@ -4,7 +4,7 @@ Working with Message Lists
 
 Mail folders could contain a *lot* of messages: thousands, tens of thousands, or even hundreds of thousands.
 
-It would be a very bad idea to deal with that many messages at once, so the WebExtensions APIs split any response that could contain many messages into pages (or chunks, or groups, or whatever…). The default size of each page is 100 messages, although this could change and you **must not** rely on that number.
+It would be a very bad idea to deal with that many messages at once, so the WebExtensions APIs split any response that could contain many messages into pages (or chunks). The default size of each page is 100 messages, although this could change and you **must not** rely on that number.
 
 Each page is an object with two properties: ``id``, and ``messages``. To get the next page, call :ref:`messages.continueList` with the ``id`` property as an argument:
 
@@ -22,8 +22,8 @@ You could also wrap this code in a generator for ease-of-use:
 
 .. code-block:: javascript
 
-  async function* listMessages(folder) {
-    let page = await messenger.messages.list(folder);
+  async function* getMessages(list) {
+    let page = await list;
     for (let message of page.messages) {
       yield message;
     }
@@ -36,7 +36,7 @@ You could also wrap this code in a generator for ease-of-use:
     }
   }
 
-  let messages = listMessages(folder);
+  let messages = getMessages(messenger.messages.list(folder));
   for await (let message of messages) {
     // Do something with the message.
     let full = await messenger.messages.getFull(message.id);