chore: flat out the file structure

include/furvm/fwd.hpp

@@ -0,0 +1,218 @@
+#ifndef FURVM_FWD_HPP
+#define FURVM_FWD_HPP
+
+#include <cstddef> // IWYU pragma: export
+#include <cstdint> // IWYU pragma: export
+#include <memory>
+#include <string>
+
+/**
+ * @brief Furlang's virtual machine.
+ */
+namespace furvm {
+
+/**
+ * @brief A byte.
+ *
+ * There's nothing more to it.
+ */
+using byte = std::uint8_t;
+
+/**
+ * @brief An offset into bytecode.
+ */
+using bytecode_pos = std::uint64_t;
+
+/**
+ * @brief Handle header with reference count.
+ */
+template <typename Id>
+class refcount_header;
+
+/**
+ * @brief Generic handle header.
+ */
+template <typename Id>
+class generic_header;
+
+/**
+ * @brief Generic furvm object handle.
+ *
+ * @tparam Value Type of the handle's value.
+ * @tparam Header Type of the handle's header.
+ */
+template <typename Value, typename Header>
+class handle;
+
+/**
+ * @brief Container for the handles.
+ *
+ * @tparam Handle Type of the container's handle.
+ */
+template <typename Handle, typename = void>
+class handle_container;
+
+// constant.hpp
+
+/**
+ * @brief Constant index.
+ *
+ * An index to the constant in module's constant pool.
+ */
+using constant_index = std::uint16_t;
+
+/**
+ * @enum constant_t
+ * @brief Constant type.
+ */
+enum class constant_t : std::uint8_t;
+
+/**
+ * @class constant
+ * @brief Constant.
+ */
+class constant;
+
+// instruction.hpp
+
+struct instruction_argument;
+
+/**
+ * @struct instruction
+ * @brief Furvm's instruction.
+ */
+struct instruction;
+
+// function.hpp
+
+/**
+ * @enum function_t
+ * @brief Function type.
+ */
+enum class function_t : std::uint8_t;
+
+/**
+ * @class function
+ * @brief Function.
+ *
+ * A furvm function.
+ */
+class function;
+
+/**
+ * @brief Furvm function's index.
+ */
+using function_id = std::uint16_t;
+
+/**
+ * @brief A handle to a furvm function.
+ */
+using function_h = handle<function, refcount_header<function_id>>;
+
+// module.hpp
+
+struct mod_type;
+
+using mod_type_id = std::uint32_t;
+
+using mod_type_h = handle<mod_type, generic_header<mod_type_id>>;
+
+/**
+ * @class mod
+ * @brief Module.
+ *
+ * A furvm module. Translation unit of furlang.
+ */
+class mod;
+
+/**
+ * @brief An alias to a module shared pointer.
+ */
+using mod_p = std::shared_ptr<mod>;
+
+/**
+ * @brief An alias for a module's identifier.
+ */
+using mod_id = std::string;
+
+/**
+ * @brief A handle to a furvm module.
+ */
+using mod_h = handle<mod, refcount_header<mod_id>>;
+
+// thing.hpp
+
+/**
+ * @class bad_thing_access
+ * @brief Bad thing access exception.
+ */
+class bad_thing_access;
+
+using thing_type_id = std::uint32_t;
+
+/**
+ * @class thing
+ * @brief Furvm thing.
+ *
+ * A stack element. Think of it like of a value in C++ or I guess a class in java.
+ */
+template <template <typename> typename Allocator = std::allocator>
+class thing;
+
+/**
+ * @brief Furvm thing's index.
+ */
+using thing_id = std::uint32_t;
+
+// executor.hpp
+
+/**
+ * @brief A variable index type.
+ */
+using variable_t = std::uint16_t;
+
+/**
+ * @enum executor_flags
+ * @brief Flags of an executor.
+ */
+enum class executor_flags : std::uint32_t;
+
+/**
+ * @class executor
+ * @brief Furvm executor.
+ *
+ * Furvm executors are like threads.
+ */
+class executor;
+
+/**
+ * @brief Furvm executor's index.
+ */
+using executor_id = std::uint32_t;
+
+// context.hpp
+
+/**
+ * @class context
+ * @brief Context.
+ *
+ * A furvm context.
+ */
+class context;
+
+/**
+ * @brief An alias to a context shared pointer.
+ */
+using context_p = std::shared_ptr<context>;
+
+// exceptions.hpp:
+
+/**
+ * @class stack_underflow
+ * @brief Stack underflow exception.
+ */
+class stack_underflow;
+
+} // namespace furvm
+
+#endif // FURVM_FWD_HPP