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#pragma once
#include <cassert>
#include <optional>
#include <string>
#include <variant>
#include <vector>
namespace rttt {
namespace hackernews {
using ItemId = int;
using ItemIds = std::vector<ItemId>;
struct Story {
std::string by = "";
int descendants = 0;
ItemId id = 0;
ItemIds kids;
int score = 0;
uint64_t time = 0;
std::string text = "";
std::string title = "";
std::string url = "";
std::string domain = "";
};
struct Comment {
std::string by = "";
ItemId id = 0;
ItemIds kids;
ItemId parent = 0;
std::string text = "";
uint64_t time = 0;
};
} // namespace hackernews
namespace rss {
struct Story {
std::string by = "";
uint64_t time = 0;
std::string text = "";
std::string title = "";
std::string domain = "";
std::string url = "";
int id;
std::string key = "";
};
} // namespace rss
// Forward declarations
namespace reddit {
struct Story;
struct Comment;
} // namespace reddit
struct Unknown {};
using ItemVariant =
std::variant<reddit::Comment, reddit::Story, hackernews::Comment,
hackernews::Story, rss::Story, Unknown>;
namespace reddit {
struct Story {
std::string by = "";
int descendants = 0;
int score = 0;
uint64_t time = 0;
std::string text = "";
std::string title = "";
std::string domain = "";
std::string url = "";
std::vector<ItemVariant> kids;
std::string id = "";
};
struct Comment {
std::string by = "";
std::string text = "";
std::string id = "";
uint64_t time = 0;
std::vector<ItemVariant> kids;
};
} // namespace reddit
inline std::optional<std::string> try_id_string(const ItemVariant &item) {
if (std::holds_alternative<reddit::Story>(item)) {
auto value = std::get<reddit::Story>(item);
if (value.id.empty())
return std::nullopt;
return value.id;
}
if (std::holds_alternative<reddit::Comment>(item)) {
auto value = std::get<reddit::Comment>(item);
if (value.id.empty())
return std::nullopt;
return value.id;
}
if (std::holds_alternative<hackernews::Story>(item)) {
auto value = std::get<hackernews::Story>(item);
if (value.id == 0)
return std::nullopt;
return std::to_string(value.id);
}
if (std::holds_alternative<hackernews::Comment>(item)) {
auto value = std::get<hackernews::Comment>(item);
if (value.id == 0)
return std::nullopt;
return std::to_string(value.id);
}
if (std::holds_alternative<rss::Story>(item)) {
auto value = std::get<rss::Story>(item);
if (value.id == 0)
return std::nullopt;
return std::to_string(value.id);
}
return std::nullopt;
}
inline std::optional<uint64_t> try_time(const ItemVariant &item) {
std::optional<uint64_t> opt;
std::visit(
[&opt](const auto &data) {
if constexpr (!std::is_same<const rttt::Unknown &,
decltype(data)>::value) {
opt = data.time;
}
},
item);
return opt;
}
template <typename C, typename = void> struct has_url : std::false_type {};
template <typename C>
struct has_url<
C, typename std::enable_if<std::is_same<decltype(std::declval<C>().url),
std::string>::value>::type>
: std::true_type {};
inline std::optional<std::string> try_url(const ItemVariant &item) {
std::optional<std::string> opt;
std::visit(
[&opt](const auto &data) {
if constexpr (has_url<decltype(data)>::value)
opt = data.url;
},
item);
return opt;
}
inline std::optional<std::string> try_text(const ItemVariant &item) {
std::optional<std::string> opt;
std::visit(
[&opt](const auto &data) {
if constexpr (!std::is_same<const rttt::Unknown &,
decltype(data)>::value) {
opt = data.text;
}
},
item);
return opt;
}
inline std::optional<std::vector<ItemVariant>>
try_kids(const ItemVariant &item) {
if (std::holds_alternative<reddit::Story>(item)) {
return std::get<reddit::Story>(item).kids;
}
if (std::holds_alternative<reddit::Comment>(item)) {
return std::get<reddit::Comment>(item).kids;
}
if (std::holds_alternative<hackernews::Comment>(item) ||
std::holds_alternative<hackernews::Story>(item)) {
assert(false); // kids work different here, so not supported (yet?)
}
return std::nullopt;
}
template <typename C, typename = void> struct has_text : std::false_type {};
template <typename C>
struct has_text<
C, typename std::enable_if<std::is_same<decltype(std::declval<C>().text),
std::string>::value>::type>
: std::true_type {};
} // namespace rttt
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