const bq1 = node('blockquote', 'quote');
const bq2 = node('p', 'another quote');
const processedHtml = map(element => {
    if( is('blockquote', element)) {
        return node('p', value(element));
    }
    return element;
    }, append(append(make(), bq1), bq2));

export const map = (func, elements) => {
    if (isEmpty(elements)) {
        return l();
    }
    const newElement = func(head(elements);
    return cons(newElement, map(func, tail(elements)));
}

export const filter = (func, elements) => {
    if (isEmpty(elements)) {
        return l();
    }
    const current = head(elements);
    const tailElements = tail(elements);
    if (func(current)) {
        return cons(current, filter(func, tailElements);
    }
    return filter(func, tailElements);
};
///итеративно!
export const filter = (func, elements) => {
  const iter = (dom, acc) => {
    if (isEmpty(dom)) {
      return acc;
    }
    const current = head(dom);
    const tailElements = tail(dom);
    if (func(current)) {
      return iter(tailElements, cons(current, acc));
    }
    return iter(tailElements, acc);
  }
  return reverse(iter(elements, l()));
};