使用带有数组作为参数的Design Documents

I'd like to update a document using Design Documents. I use PHP-on-Couch and call the design document like this:

$client->updateDoc("updateDocumentInfo", "infoUpdate", array(...), $docid);

The necessary information for the update are inside the array() statement. However, I can't figure out how to access the array inside my design document:

{
  "_id": "_design/updateDocumentInfo",
  "_rev": "...",
  "updates": {
    "infoUpdate": "function(doc, req) {doc.Name = ......;  var message = 'test'; return [doc, message];}"
  }
}

Does somebody know how I access an array inside this document?

Best regards