void xl_set_documentation(Tree *node, text doc)
// ----------------------------------------------------------------------------
//   Attach the documentation to the node as a comment
// ----------------------------------------------------------------------------
{
    if (!doc.empty())
    {
        std::vector<text> com(1,doc);
        CommentsInfo *cinfo = new CommentsInfo();
        cinfo->after = com;
        node->SetInfo<CommentsInfo> (cinfo);
    }
}