static S ai_renderNodesList(L<WebNode> l) {
  ret ai_renderNodesList(l, "-");
}

static S ai_renderNodesList(L<WebNode> l, S defaultText) {
  ret empty(l) ? defaultText : joinWithComma(map web_text(l));
}

static S ai_renderNodesList(L<WebNode> l, S defaultText, S joiner) {
  ret empty(l) ? defaultText : join(joiner, map web_text(l));
}