인프런 커뮤니티 질문&답변

const sum = (f) => pipe(
    map(f),
    reduce(add),
  );

  const total_quantity = sum(
    p => p.quantity
  );

  log(total_quantity(products));

  const total_price = sum(
    p => p.price * p.quantity
  );

  log(total_price(products));