Rework Grammar and Parser

Properly construct headless binary with basic validation and print functionality

Add Error and Warning structs to Parser
Add FileNode pointer getter to Parser
Change all `char8_t*` and `const char8_t` to `const char*` in Parser
Add Parser move operators and Parser deconstructor
Add BufferHandler PIMPL object to Parser
Add UTF-8 file Warning

Add proper Grammar value retrieval
Simplify AST node resolution for Grammar

Add AbstractSyntaxTree for v2script data parser:
	Has compile-time embedded type information accessible at compile-time and runtime
	Optionally compiled AST print functionality

Add detail/TypeName.hpp
Add detail/SelfType.hpp
Add detail/DetectUtf8.hpp
Add detail/Errors.hpp
Add detail/Warnings.hpp

Add `OPENVIC_DATALOADER_PRINT_NODES` for headless construction
Fix wrong environment reference for headless construction in SConstruct

4 files changed, 313 insertions, 11 deletions

diff --git a/include/openvic-dataloader/detail/SelfType.hpp b/include/openvic-dataloader/detail/SelfType.hpp
new file mode 100644
index 0000000..5366aef
--- /dev/null
+++ b/include/openvic-dataloader/detail/SelfType.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <type_traits>
+
+namespace ovdl::detail {
+#pragma GCC diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma GCC diagnostic ignored "-Wnon-template-friend"
+	template<typename T>
+	struct Reader {
+		friend auto adl_GetSelfType(Reader<T>);
+	};
+
+	template<typename T, typename U>
+	struct Writer {
+		friend auto adl_GetSelfType(Reader<T>) { return U {}; }
+	};
+#pragma GCC diagnostic pop
+
+	inline void adl_GetSelfType() {}
+
+	template<typename T>
+	using Read = std::remove_pointer_t<decltype(adl_GetSelfType(Reader<T> {}))>;
+}
diff --git a/include/openvic-dataloader/detail/TypeName.hpp b/include/openvic-dataloader/detail/TypeName.hpp
new file mode 100644
index 0000000..e9f27d3
--- /dev/null
+++ b/include/openvic-dataloader/detail/TypeName.hpp
@@ -0,0 +1,52 @@
+#pragma once
+
+#include <array>
+#include <cstddef>
+#include <string_view>
+#include <utility>
+
+namespace ovdl::detail {
+
+	template<std::size_t... Idxs>
+	constexpr auto substring_as_array(std::string_view str, std::index_sequence<Idxs...>) {
+		return std::array { str[Idxs]..., '\n' };
+	}
+
+	template<typename T>
+	constexpr auto type_name_array() {
+#if defined(__clang__)
+		constexpr auto prefix = std::string_view { "[T = " };
+		constexpr auto suffix = std::string_view { "]" };
+		constexpr auto function = std::string_view { __PRETTY_FUNCTION__ };
+#elif defined(__GNUC__)
+		constexpr auto prefix = std::string_view { "with T = " };
+		constexpr auto suffix = std::string_view { "]" };
+		constexpr auto function = std::string_view { __PRETTY_FUNCTION__ };
+#elif defined(_MSC_VER)
+		constexpr auto prefix = std::string_view { "type_name_array<" };
+		constexpr auto suffix = std::string_view { ">(void)" };
+		constexpr auto function = std::string_view { __FUNCSIG__ };
+#else
+#error Unsupported compiler
+#endif
+
+		constexpr auto start = function.find(prefix) + prefix.size();
+		constexpr auto end = function.rfind(suffix);
+
+		static_assert(start < end);
+
+		constexpr auto name = function.substr(start, (end - start));
+		return substring_as_array(name, std::make_index_sequence<name.size()> {});
+	}
+
+	template<typename T>
+	struct type_name_holder {
+		static inline constexpr auto value = type_name_array<T>();
+	};
+
+	template<typename T>
+	constexpr auto type_name() -> std::string_view {
+		constexpr auto& value = type_name_holder<T>::value;
+		return std::string_view { value.data(), value.size() };
+	}
+}
\ No newline at end of file
diff --git a/include/openvic-dataloader/v2script/AbstractSyntaxTree.hpp b/include/openvic-dataloader/v2script/AbstractSyntaxTree.hpp
new file mode 100644
index 0000000..80485b7
--- /dev/null
+++ b/include/openvic-dataloader/v2script/AbstractSyntaxTree.hpp
@@ -0,0 +1,174 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include <openvic-dataloader/detail/SelfType.hpp>
+#include <openvic-dataloader/detail/TypeName.hpp>
+
+#ifdef OPENVIC_DATALOADER_PRINT_NODES
+#include <iostream>
+
+#define OVDL_PRINT_FUNC_DECL virtual void print(std::ostream& stream) const = 0
+#define OVDL_PRINT_FUNC_DEF(...) \
+	void print(std::ostream& stream) const override __VA_ARGS__
+#else
+#define OVDL_PRINT_FUNC_DECL
+#define OVDL_PRINT_FUNC_DEF(...)
+#endif
+
+// defines get_type_static and get_type for string type naming
+#define OVDL_RT_TYPE_DEF                                                                              \
+	static constexpr std::string_view get_type_static() { return ::ovdl::detail::type_name<type>(); } \
+	constexpr std::string_view get_type() const override { return ::ovdl::detail::type_name<std::decay_t<decltype(*this)>>(); }
+
+// defines type for self-class referencing
+#define OVDL_TYPE_DEFINE_SELF                                                                                \
+	struct _self_type_tag {};                                                                                \
+	constexpr auto _self_type_helper()->decltype(::ovdl::detail::Writer<_self_type_tag, decltype(this)> {}); \
+	using type = ::ovdl::detail::Read<_self_type_tag>;
+
+namespace ovdl::v2script::ast {
+	struct Node {
+		Node(const Node&) = delete;
+		Node& operator=(const Node&) = delete;
+		Node() = default;
+		Node(Node&&) = default;
+		Node& operator=(Node&&) = default;
+		virtual ~Node() = default;
+
+		OVDL_PRINT_FUNC_DECL;
+
+		static constexpr std::string_view get_type_static() { return detail::type_name<Node>(); }
+		constexpr virtual std::string_view get_type() const = 0;
+
+		template<typename T>
+		constexpr bool is_type() const {
+			return get_type().compare(detail::type_name<T>()) == 0;
+		}
+	};
+
+	using NodePtr = Node*;
+	using NodeUPtr = std::unique_ptr<Node>;
+
+	template<class T, class... Args>
+	NodePtr make_node_ptr(Args&&... args) {
+		if constexpr (std::is_pointer_v<NodePtr>) {
+			return new T(std::forward<Args>(args)...);
+		} else {
+			return NodePtr(new T(std::forward<Args>(args)...));
+		}
+	}
+
+	template<typename To, typename From>
+	To& cast_node_ptr(const From& from) {
+		if constexpr (std::is_pointer_v<NodePtr>) {
+			return *static_cast<To*>(from);
+		} else {
+			return *static_cast<To*>(from.get());
+		}
+	}
+
+	constexpr std::vector<NodeUPtr> make_node_ptr_vector(const std::vector<NodePtr>& ptrs) {
+		std::vector<NodeUPtr> result;
+		result.reserve(ptrs.size());
+		for (auto&& p : ptrs) {
+			result.push_back(NodeUPtr(p));
+		}
+		return result;
+	}
+
+	struct IdentifierNode final : public Node {
+		std::string _name;
+		explicit IdentifierNode(std::string name)
+			: _name(std::move(name)) {
+		}
+
+		OVDL_TYPE_DEFINE_SELF;
+		OVDL_RT_TYPE_DEF;
+
+		OVDL_PRINT_FUNC_DEF({
+			stream << _name.c_str();
+		})
+	};
+
+	struct StringNode final : public Node {
+		std::string _name;
+		explicit StringNode(std::string name)
+			: _name(std::move(name)) {
+		}
+
+		OVDL_TYPE_DEFINE_SELF;
+		OVDL_RT_TYPE_DEF;
+
+		OVDL_PRINT_FUNC_DEF({
+			stream << '"' << _name.c_str() << '"';
+		})
+	};
+
+	struct AssignNode final : public Node {
+		std::string _name;
+		NodeUPtr _initializer;
+		explicit AssignNode(NodePtr name, NodePtr init)
+			: _initializer(std::move(init)) {
+			if (name->is_type<IdentifierNode>()) {
+				_name = cast_node_ptr<IdentifierNode>(name)._name;
+			}
+		}
+
+		OVDL_TYPE_DEFINE_SELF;
+		OVDL_RT_TYPE_DEF;
+
+		OVDL_PRINT_FUNC_DEF({
+			stream << _name.c_str() << " = ";
+			_initializer->print(stream);
+		})
+	};
+
+	struct ListNode final : public Node {
+		std::vector<NodeUPtr> _statements;
+		explicit ListNode(std::vector<NodePtr> statements = std::vector<NodePtr> {})
+			: _statements(make_node_ptr_vector(statements)) {
+		}
+
+		OVDL_TYPE_DEFINE_SELF;
+		OVDL_RT_TYPE_DEF;
+
+		OVDL_PRINT_FUNC_DEF({
+			stream << '{';
+			for (int i = 0; i < _statements.size(); i++) {
+				auto& statement = _statements[i];
+				statement->print(stream);
+				if (i + 1 != _statements.size())
+					stream << ' ';
+			}
+			stream << '}';
+		})
+	};
+
+	struct FileNode final : public Node {
+		std::vector<NodeUPtr> _statements;
+		FileNode() {}
+		explicit FileNode(std::vector<NodePtr> statements)
+			: _statements(make_node_ptr_vector(statements)) {
+		}
+
+		OVDL_TYPE_DEFINE_SELF;
+		OVDL_RT_TYPE_DEF;
+
+		OVDL_PRINT_FUNC_DEF({
+			for (auto& statement : _statements) {
+				statement->print(stream);
+				stream << "\n===========\n";
+			}
+		})
+	};
+}
+
+#undef OVDL_PRINT_FUNC_DECL
+#undef OVDL_PRINT_FUNC_DEF
+#undef OVDL_TYPE_DEFINE_SELF
\ No newline at end of file
diff --git a/include/openvic-dataloader/v2script/Parser.hpp b/include/openvic-dataloader/v2script/Parser.hpp
index 53aab90..dbbec73 100644
--- a/include/openvic-dataloader/v2script/Parser.hpp
+++ b/include/openvic-dataloader/v2script/Parser.hpp
@@ -1,27 +1,79 @@
 #pragma once
 
 #include <cstddef>
-#include <cstdio>
+#include <functional>
+#include <memory>
+#include <optional>
 #include <ostream>
+#include <string>
+#include <vector>
+
+#include <openvic-dataloader/v2script/AbstractSyntaxTree.hpp>
 
 namespace ovdl::v2script {
+
+	using FileNode = ast::FileNode;
+
 	class Parser {
 	public:
-		static Parser from_buffer(char8_t* data, std::size_t size);
-		static Parser from_buffer(char8_t* start, char8_t* end);
-		static Parser from_file(const char8_t* path);
+		struct Error {
+			const enum class Type : unsigned char {
+				Recoverable,
+				Fatal
+			} type;
+			const std::string message;
+			const int error_value;
+		};
+
+		struct Warning {
+			const std::string message;
+			const int warning_value;
+		};
+
+		Parser();
+
+		static Parser from_buffer(const char* data, std::size_t size);
+		static Parser from_buffer(const char* start, const char* end);
+		static Parser from_file(const char* path);
+
+		Parser& load_from_buffer(const char* data, std::size_t size);
+		Parser& load_from_buffer(const char* start, const char* end);
+		Parser& load_from_file(const char* path);
 
+		void set_error_log_to_null();
 		void set_error_log_to_stderr();
-		void set_error_log_path(const char8_t* path);
-		void set_error_log_to(std::basic_ostream<char8_t> stream);
-		void set_error_log_to(std::FILE* file);
+		void set_error_log_to_stdout();
+		void set_error_log_to(std::basic_ostream<char>& stream);
 
-		bool parse();
+		bool simple_parse();
 
-		bool has_error();
-		bool has_warning();
+		bool has_error() const;
+		bool has_fatal_error() const;
+		bool has_warning() const;
+
+		const std::vector<Error>& get_errors() const;
+		const std::vector<Warning>& get_warnings() const;
+
+		const FileNode* get_file_node() const;
+
+		Parser(Parser&&);
+		Parser& operator=(Parser&&);
+
+		~Parser();
 
 	private:
-		Parser();
+		std::vector<Error> _errors;
+		std::vector<Warning> _warnings;
+
+		class BufferHandler;
+		friend class BufferHandler;
+		std::unique_ptr<BufferHandler> _buffer_handler;
+		std::unique_ptr<FileNode> _file_node;
+		std::reference_wrapper<std::ostream> _error_stream;
+		const char* _file_path;
+		bool _has_fatal_error = false;
+
+		template<typename... Args>
+		inline void _run_load_func(std::optional<Error> (BufferHandler::*func)(Args...), Args... args);
 	};
 }
\ No newline at end of file