sol2/sol/table_core.hpp

// The MIT License (MIT) 

// Copyright (c) 2013-2016 Rapptz, ThePhD and contributors

// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
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// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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#ifndef SOL_TABLE_CORE_HPP
#define SOL_TABLE_CORE_HPP

#include "proxy.hpp"
#include "stack.hpp"
#include "function_types.hpp"
#include "usertype.hpp"
#include "table_iterator.hpp"

namespace sol {
	namespace detail {
		template <std::size_t n>
		struct clean { lua_State* L; clean(lua_State* L) : L(L) {} ~clean() { lua_pop(L, static_cast<int>(n)); } };
		struct ref_clean { lua_State* L; int& n; ref_clean(lua_State* L, int& n) : L(L), n(n) {} ~ref_clean() { lua_pop(L, static_cast<int>(n)); } };
		inline int fail_on_newindex(lua_State* L) {
			return luaL_error(L, "sol: cannot modify the elements of an enumeration table");
		}
	}

	template <bool top_level, typename base_t>
	class basic_table_core : public base_t {
		friend class state;
		friend class state_view;

		template <typename... Args>
		using is_global = meta::all<meta::boolean<top_level>, meta::is_c_str<Args>...>;

		template<typename Fx>
		void for_each(std::true_type, Fx&& fx) const {
			auto pp = stack::push_pop(*this);
			stack::push(base_t::lua_state(), nil);
			while (lua_next(base_t::lua_state(), -2)) {
				sol::object key(base_t::lua_state(), -2);
				sol::object value(base_t::lua_state(), -1);
				std::pair<sol::object&, sol::object&> keyvalue(key, value);
				auto pn = stack::pop_n(base_t::lua_state(), 1);
				fx(keyvalue);
			}
		}

		template<typename Fx>
		void for_each(std::false_type, Fx&& fx) const {
			auto pp = stack::push_pop(*this);
			stack::push(base_t::lua_state(), nil);
			while (lua_next(base_t::lua_state(), -2)) {
				sol::object key(base_t::lua_state(), -2);
				sol::object value(base_t::lua_state(), -1);
				auto pn = stack::pop_n(base_t::lua_state(), 1);
				fx(key, value);
			}
		}

		template<typename Ret0, typename Ret1, typename... Ret, std::size_t... I, typename Keys>
		auto tuple_get(types<Ret0, Ret1, Ret...>, std::index_sequence<0, 1, I...>, Keys&& keys) const
			-> decltype(stack::pop<std::tuple<Ret0, Ret1, Ret...>>(nullptr)) {
			typedef decltype(stack::pop<std::tuple<Ret0, Ret1, Ret...>>(nullptr)) Tup;
			return Tup(
				traverse_get_optional<top_level, Ret0>(meta::is_specialization_of<sol::optional, meta::unqualified_t<Ret0>>(), detail::forward_get<0>(keys)),
				traverse_get_optional<top_level, Ret1>(meta::is_specialization_of<sol::optional, meta::unqualified_t<Ret1>>(), detail::forward_get<1>(keys)),
				traverse_get_optional<top_level, Ret>(meta::is_specialization_of<sol::optional, meta::unqualified_t<Ret>>(), detail::forward_get<I>(keys))...
			);
		}

		template<typename Ret, std::size_t I, typename Keys>
		decltype(auto) tuple_get(types<Ret>, std::index_sequence<I>, Keys&& keys) const {
			return traverse_get_optional<top_level, Ret>(meta::is_specialization_of<sol::optional, meta::unqualified_t<Ret>>(), detail::forward_get<I>(keys));
		}

		template<typename Pairs, std::size_t... I>
		void tuple_set(std::index_sequence<I...>, Pairs&& pairs) {
			auto pp = stack::push_pop<top_level && (is_global<decltype(detail::forward_get<I * 2>(pairs))...>::value)>(*this);
			void(detail::swallow{ (stack::set_field<top_level>(base_t::lua_state(),
				detail::forward_get<I * 2>(pairs),
				detail::forward_get<I * 2 + 1>(pairs),
				lua_gettop(base_t::lua_state())
			), 0)... });
		}

		template <bool global, typename T, typename Key>
		decltype(auto) traverse_get_deep(Key&& key) const {
			stack::get_field<global>(base_t::lua_state(), std::forward<Key>(key));
			return stack::get<T>(base_t::lua_state());
		}

		template <bool global, typename T, typename Key, typename... Keys>
		decltype(auto) traverse_get_deep(Key&& key, Keys&&... keys) const {
			stack::get_field<global>(base_t::lua_state(), std::forward<Key>(key));
			return traverse_get_deep<false, T>(std::forward<Keys>(keys)...);
		}

		template <bool global, typename T, std::size_t I, typename Key>
		decltype(auto) traverse_get_deep_optional(int& popcount, Key&& key) const {
			typedef decltype(stack::get<T>(base_t::lua_state())) R;
			auto p = stack::probe_get_field<global>(base_t::lua_state(), std::forward<Key>(key), lua_gettop(base_t::lua_state()));
			popcount += p.levels;
			if (!p.success)
				return R(nullopt);
			return stack::get<T>(base_t::lua_state());
		}

		template <bool global, typename T, std::size_t I, typename Key, typename... Keys>
		decltype(auto) traverse_get_deep_optional(int& popcount, Key&& key, Keys&&... keys) const {
			auto p = I > 0 ? stack::probe_get_field<global>(base_t::lua_state(), std::forward<Key>(key), -1) : stack::probe_get_field<global>(base_t::lua_state(), std::forward<Key>(key), lua_gettop(base_t::lua_state()));
			popcount += p.levels;
			if (!p.success)
				return T(nullopt);
			return traverse_get_deep_optional<false, T, I + 1>(popcount, std::forward<Keys>(keys)...);
		}

		template <bool global, typename T, typename... Keys>
		decltype(auto) traverse_get_optional(std::false_type, Keys&&... keys) const {
			detail::clean<sizeof...(Keys)> c(base_t::lua_state());
			return traverse_get_deep<top_level, T>(std::forward<Keys>(keys)...);
		}

		template <bool global, typename T, typename... Keys>
		decltype(auto) traverse_get_optional(std::true_type, Keys&&... keys) const {
			int popcount = 0;
			detail::ref_clean c(base_t::lua_state(), popcount);
			return traverse_get_deep_optional<top_level, T, 0>(popcount, std::forward<Keys>(keys)...);
		}

		template <bool global, typename Key, typename Value>
		void traverse_set_deep(Key&& key, Value&& value) const {
			stack::set_field<global>(base_t::lua_state(), std::forward<Key>(key), std::forward<Value>(value));
		}

		template <bool global, typename Key, typename... Keys>
		void traverse_set_deep(Key&& key, Keys&&... keys) const {
			stack::get_field<global>(base_t::lua_state(), std::forward<Key>(key));
			traverse_set_deep<false>(std::forward<Keys>(keys)...);
		}

		basic_table_core(lua_State* L, detail::global_tag t) noexcept : reference(L, t) { }

	public:
		typedef basic_table_iterator<base_t> iterator;
		typedef iterator const_iterator;

		basic_table_core() noexcept : base_t() { }
		template <typename T, meta::enable<meta::neg<std::is_same<meta::unqualified_t<T>, basic_table_core>>, std::is_base_of<base_t, meta::unqualified_t<T>>> = meta::enabler>
		basic_table_core(T&& r) noexcept : base_t(std::forward<T>(r)) {
#ifdef SOL_CHECK_ARGUMENTS
			if (!is_table<meta::unqualified_t<T>>::value) {
				auto pp = stack::push_pop(*this);
				stack::check<basic_table_core>(base_t::lua_state(), -1, type_panic);
			}
#endif // Safety
		}
		basic_table_core(const basic_table_core&) = default;
		basic_table_core(basic_table_core&&) = default;
		basic_table_core& operator=(const basic_table_core&) = default;
		basic_table_core& operator=(basic_table_core&&) = default;
		basic_table_core(const stack_reference& r) : basic_table_core(r.lua_state(), r.stack_index()) {}
		basic_table_core(stack_reference&& r) : basic_table_core(r.lua_state(), r.stack_index()) {}
		basic_table_core(lua_State* L, int index = -1) : base_t(L, index) {
#ifdef SOL_CHECK_ARGUMENTS
			stack::check<basic_table_core>(L, index, type_panic);
#endif // Safety
		}

		iterator begin() const {
			return iterator(*this);
		}

		iterator end() const {
			return iterator();
		}

		const_iterator cbegin() const {
			return begin();
		}

		const_iterator cend() const {
			return end();
		}

		template<typename... Ret, typename... Keys>
		decltype(auto) get(Keys&&... keys) const {
			static_assert(sizeof...(Keys) == sizeof...(Ret), "number of keys and number of return types do not match");
			auto pp = stack::push_pop<is_global<Keys...>::value>(*this);
			return tuple_get(types<Ret...>(), std::make_index_sequence<sizeof...(Ret)>(), std::forward_as_tuple(std::forward<Keys>(keys)...));
		}

		template<typename T, typename Key>
		decltype(auto) get_or(Key&& key, T&& otherwise) const {
			typedef decltype(get<T>("")) U;
			sol::optional<U> option = get<sol::optional<U>>(std::forward<Key>(key));
			if (option) {
				return static_cast<U>(option.value());
			}
			return static_cast<U>(std::forward<T>(otherwise));
		}

		template<typename T, typename Key, typename D>
		decltype(auto) get_or(Key&& key, D&& otherwise) const {
			sol::optional<T> option = get<sol::optional<T>>(std::forward<Key>(key));
			if (option) {
				return static_cast<T>(option.value());
			}
			return static_cast<T>(std::forward<D>(otherwise));
		}

		template <typename T, typename... Keys>
		decltype(auto) traverse_get(Keys&&... keys) const {
			auto pp = stack::push_pop<is_global<Keys...>::value>(*this);
			return traverse_get_optional<top_level, T>(meta::is_specialization_of<sol::optional, meta::unqualified_t<T>>(), std::forward<Keys>(keys)...);
		}

		template <typename... Keys>
		basic_table_core& traverse_set(Keys&&... keys) {
			auto pp = stack::push_pop<is_global<Keys...>::value>(*this);
			auto pn = stack::pop_n(base_t::lua_state(), static_cast<int>(sizeof...(Keys)-2));
			traverse_set_deep<top_level>(std::forward<Keys>(keys)...);
			return *this;
		}

		template<typename... Args>
		basic_table_core& set(Args&&... args) {
			tuple_set(std::make_index_sequence<sizeof...(Args) / 2>(), std::forward_as_tuple(std::forward<Args>(args)...));
			return *this;
		}

		template<typename T>
		basic_table_core& set_usertype(usertype<T>& user) {
			return set_usertype(usertype_traits<T>::name, user);
		}

		template<typename Key, typename T>
		basic_table_core& set_usertype(Key&& key, usertype<T>& user) {
			return set(std::forward<Key>(key), user);
		}

		template<typename Class, typename... Args>
		basic_table_core& new_usertype(const std::string& name, Args&&... args) {
			usertype<Class> utype(std::forward<Args>(args)...);
			set_usertype(name, utype);
			return *this;
		}

		template<typename Class, typename CTor0, typename... CTor, typename... Args>
		basic_table_core& new_usertype(const std::string& name, Args&&... args) {
			constructors<types<CTor0, CTor...>> ctor{};
			return new_usertype<Class>(name, ctor, std::forward<Args>(args)...);
		}

		template<typename Class, typename... CArgs, typename... Args>
		basic_table_core& new_usertype(const std::string& name, constructors<CArgs...> ctor, Args&&... args) {
			usertype<Class> utype(ctor, std::forward<Args>(args)...);
			set_usertype(name, utype);
			return *this;
		}

		template<typename Class, typename... Args>
		basic_table_core& new_simple_usertype(const std::string& name, Args&&... args) {
			usertype<Class> utype(simple, base_t::lua_state(), std::forward<Args>(args)...);
			set_usertype(name, utype);
			return *this;
		}

		template<typename Class, typename CTor0, typename... CTor, typename... Args>
		basic_table_core& new_simple_usertype(const std::string& name, Args&&... args) {
			constructors<types<CTor0, CTor...>> ctor{};
			return new_simple_usertype<Class>(name, ctor, std::forward<Args>(args)...);
		}

		template<typename Class, typename... CArgs, typename... Args>
		basic_table_core& new_simple_usertype(const std::string& name, constructors<CArgs...> ctor, Args&&... args) {
			usertype<Class> utype(simple, base_t::lua_state(), ctor, std::forward<Args>(args)...);
			set_usertype(name, utype);
			return *this;
		}

		template<bool read_only = true, typename... Args>
		basic_table_core& new_enum(const std::string& name, Args&&... args) {
			if (read_only) {
				table idx = create_with(std::forward<Args>(args)...);
				table x = create_with(
					meta_function::new_index, detail::fail_on_newindex,
					meta_function::index, idx
				);
				table target = create_named(name);
				target[metatable_key] = x;
			}
			else {
				create_named(name, std::forward<Args>(args)...);
			}
			return *this;
		}

		template<typename Fx>
		void for_each(Fx&& fx) const {
			typedef meta::is_invokable<Fx(std::pair<sol::object, sol::object>)> is_paired;
			for_each(is_paired(), std::forward<Fx>(fx));
		}

		size_t size() const {
			auto pp = stack::push_pop(*this);
			return lua_rawlen(base_t::lua_state(), -1);
		}

		bool empty() const {
			return cbegin() == cend();
		}

		template<typename T>
		proxy<basic_table_core&, T> operator[](T&& key) & {
			return proxy<basic_table_core&, T>(*this, std::forward<T>(key));
		}

		template<typename T>
		proxy<const basic_table_core&, T> operator[](T&& key) const & {
			return proxy<const basic_table_core&, T>(*this, std::forward<T>(key));
		}

		template<typename T>
		proxy<basic_table_core, T> operator[](T&& key) && {
			return proxy<basic_table_core, T>(*this, std::forward<T>(key));
		}

		template<typename Sig, typename Key, typename... Args>
		basic_table_core& set_function(Key&& key, Args&&... args) {
			set_fx(types<Sig>(), std::forward<Key>(key), std::forward<Args>(args)...);
			return *this;
		}

		template<typename Key, typename... Args>
		basic_table_core& set_function(Key&& key, Args&&... args) {
			set_fx(types<>(), std::forward<Key>(key), std::forward<Args>(args)...);
			return *this;
		}

		template <typename... Args>
		basic_table_core& add(Args&&... args) {
			auto pp = stack::push_pop(*this);
			(void)detail::swallow{0, 
				(stack::set_ref(base_t::lua_state(), std::forward<Args>(args)), 0)...
			};
			return *this;
		}

	private:
		template<typename R, typename... Args, typename Fx, typename Key, typename = std::result_of_t<Fx(Args...)>>
		void set_fx(types<R(Args...)>, Key&& key, Fx&& fx) {
			set_resolved_function<R(Args...)>(std::forward<Key>(key), std::forward<Fx>(fx));
		}

		template<typename Fx, typename Key, meta::enable<meta::is_specialization_of<overload_set, meta::unqualified_t<Fx>>> = meta::enabler>
		void set_fx(types<>, Key&& key, Fx&& fx) {
			set(std::forward<Key>(key), std::forward<Fx>(fx));
		}

		template<typename Fx, typename Key, typename... Args, meta::disable<meta::is_specialization_of<overload_set, meta::unqualified_t<Fx>>> = meta::enabler>
		void set_fx(types<>, Key&& key, Fx&& fx, Args&&... args) {
			set(std::forward<Key>(key), as_function(std::forward<Fx>(fx), std::forward<Args>(args)...));
		}

		template<typename... Sig, typename... Args, typename Key>
		void set_resolved_function(Key&& key, Args&&... args) {
			set(std::forward<Key>(key), as_function<function_sig<Sig...>>(std::forward<Args>(args)...));
		}

	public:
		static inline table create(lua_State* L, int narr = 0, int nrec = 0) {
			lua_createtable(L, narr, nrec);
			table result(L);
			lua_pop(L, 1);
			return result;
		}

		template <typename Key, typename Value, typename... Args>
		static inline table create(lua_State* L, int narr, int nrec, Key&& key, Value&& value, Args&&... args) {
			lua_createtable(L, narr, nrec);
			table result(L);
			result.set(std::forward<Key>(key), std::forward<Value>(value), std::forward<Args>(args)...);
			lua_pop(L, 1);
			return result;
		}

		template <typename... Args>
		static inline table create_with(lua_State* L, Args&&... args) {
			static const int narr = static_cast<int>(meta::count_2_for_pack<std::is_integral, Args...>::value);
			return create(L, narr, static_cast<int>((sizeof...(Args) / 2) - narr), std::forward<Args>(args)...);
		}

		table create(int narr = 0, int nrec = 0) {
			return create(base_t::lua_state(), narr, nrec);
		}

		template <typename Key, typename Value, typename... Args>
		table create(int narr, int nrec, Key&& key, Value&& value, Args&&... args) {
			return create(base_t::lua_state(), narr, nrec, std::forward<Key>(key), std::forward<Value>(value), std::forward<Args>(args)...);
		}

		template <typename Name>
		table create(Name&& name, int narr = 0, int nrec = 0) {
			table x = create(base_t::lua_state(), narr, nrec);
			this->set(std::forward<Name>(name), x);
			return x;
		}

		template <typename Name, typename Key, typename Value, typename... Args>
		table create(Name&& name, int narr, int nrec, Key&& key, Value&& value, Args&&... args) {
			table x = create(base_t::lua_state(), narr, nrec, std::forward<Key>(key), std::forward<Value>(value), std::forward<Args>(args)...);
			this->set(std::forward<Name>(name), x);
			return x;
		}

		template <typename... Args>
		table create_with(Args&&... args) {
			return create_with(base_t::lua_state(), std::forward<Args>(args)...);
		}

		template <typename Name, typename... Args>
		table create_named(Name&& name, Args&&... args) {
			static const int narr = static_cast<int>(meta::count_2_for_pack<std::is_integral, Args...>::value);
			return create(std::forward<Name>(name), narr, sizeof...(Args) / 2 - narr, std::forward<Args>(args)...);
		}
	};
} // sol

#endif // SOL_TABLE_CORE_HPP