state ===== owning and non-owning state holders for registry and globals ------------------------------------------------------------ .. code-block:: cpp class state_view; class state : state_view, std::unique_ptr; The most important class here is ``state_view``. This structure takes a ``lua_State*`` that was already created and gives you simple, easy access to Lua's interfaces without taking ownership. ``state`` derives from ``state_view``, inheriting all of this functionality, but has the additional purpose of creating a fresh ``lua_State*`` and managing its lifetime for you in the default constructor. The majority of the members between ``state_view`` and :doc:`sol::table` are identical, with added for this higher-level type. Therefore, all of the examples and notes in :doc:`sol::table
` apply here as well. enumerations ------------ .. code-block:: cpp :caption: in-lua libraries :name: lib-enum enum class lib : char { base, package, coroutine, string, os, math, table, debug, bit32, io, ffi, jit, count // do not use }; This enumeration details the various base libraries that come with Lua. See the `standard lua libraries`_ for details about the various standard libraries. members ------- .. code-block:: cpp :caption: function: open standard libraries/modules :name: open-libraries template void open_libraries(Args&&... args); This function takes a number of :ref:`sol::lib` as arguments and opens up the associated Lua core libraries. .. code-block:: cpp :caption: function: script / script_file :name: state-script-function sol::function_result script(const std::string& code); sol::protected_function_result script(const std::string& code, const environment& env); template sol::protected_function_result script(const std::string& code, Func&& func); template sol::protected_function_result script(const std::string& code, const environment& env, Func&& func); sol::function_result script_file(const std::string& filename); sol::protected_function_result script_file(const std::string& filename, const environment& env); template sol::protected_function_result script_file(const std::string& filename, Func&& func); template sol::protected_function_result script_file(const std::string& filename, const environment& env, Func&& func); These functions run the desired blob of either code that is in a string, or code that comes from a filename, on the ``lua_State*``. It will not run isolated: any scripts or code run will affect code in the ``lua_State*`` the object uses as well (unless ``local`` is applied to a variable declaration, as specified by the Lua language). Code ran in this fashion is not isolated. If you need isolation, consider creating a new state or traditional Lua sandboxing techniques. If your script returns a value, you can capture it from the returned :ref:`sol::function_result`/:ref:`sol::protected_function_result`. To handle errors when using the second overload, provide a callable function/object that takes a ``lua_State*`` as its first argument and a ``sol::protected_function_result`` as its second argument. Then, handle the errors any way you like: .. code-block:: cpp :caption: running code safely :name: state-script-safe int main () { sol::state lua; // the default handler panics or throws, depending on your settings auto result1 = lua.script("bad.code", &sol::default_on_error); auto result2 = lua.script("123 bad.code", [](lua_State* L, sol::protected_function_result pfr) { // pfr will contain things that went wrong, for either loading or executing the script // the user can do whatever they like here, including throw. Otherwise, // they need to return the protected_function_result // You can also just return it, and let the call-site handle the error if necessary. return pfr; }); } You can also pass a :doc:`sol::environment` to ``script``/``script_file`` to have the script have sandboxed / contained in a way inside of a state. This is useful for runnig multiple different "perspectives" or "views" on the same state, and even has fallback support. See the :doc:`sol::environment` documentation for more details. .. code-block:: cpp :caption: function: require / require_file :name: state-require-function sol::object require(const std::string& key, lua_CFunction open_function, bool create_global = true); sol::object require_script(const std::string& key, const std::string& code, bool create_global = true); sol::object require_file(const std::string& key, const std::string& file, bool create_global = true); These functions play a role similar to `luaL_requiref`_ except that they make this functionality available for loading a one-time script or a single file. The code here checks if a module has already been loaded, and if it has not, will either load / execute the file or execute the string of code passed in. If ``create_global`` is set to true, it will also link the name ``key`` to the result returned from the open function, the code or the file. Regardless or whether a fresh load happens or not, the returned module is given as a single :doc:`sol::object` for you to use as you see fit. Thanks to `Eric (EToreo) for the suggestion on this one`_! .. code-block:: cpp :caption: function: load / load_file :name: state-load-code sol::load_result load(const std::string& code); sol::load_result load_file(const std::string& filename); These functions *load* the desired blob of either code that is in a string, or code that comes from a filename, on the ``lua_State*``. It will not run: it returns a ``load_result`` proxy that can be called to actually run the code, turned into a ``sol::function``, a ``sol::protected_function``, or some other abstraction. If it is called, it will run on the object's current ``lua_State*``: it is not isolated. If you need isolation, consider creating a new state or traditional Lua sandboxing techniques. .. code-block:: cpp :caption: function: do_string / do_file :name: state-do-code sol::protected_function_result do_string(const std::string& code); sol::protected_function_result do_file(const std::string& filename); These functions *loads and performs* the desired blob of either code that is in a string, or code that comes from a filename, on the ``lua_State*``. It *will* run, and then return a ``protected_function_result`` proxy that can be examined for either an error or the return value. .. code-block:: cpp :caption: function: global table / registry table sol::global_table globals() const; sol::table registry() const; Get either the global table or the Lua registry as a :doc:`sol::table
`, which allows you to modify either of them directly. Note that getting the global table from a ``state``/``state_view`` is usually unnecessary as it has all the exact same functions as a :doc:`sol::table
` anyhow. .. code-block:: cpp :caption: function: set_panic :name: set-panic void set_panic(lua_CFunction panic); Overrides the panic function Lua calls when something unrecoverable or unexpected happens in the Lua VM. Must be a function of the that matches the ``int(lua_State*)`` function signature. .. code-block:: cpp :caption: function: memory_used :name: memory-used std::size_t memory_used() const; Returns the amount of memory used *in bytes* by the Lua State. .. code-block:: cpp :caption: function: collect_garbage :name: collect-garbage void collect_garbage(); Attempts to run the garbage collector. Note that this is subject to the same rules as the Lua API's collect_garbage function: memory may or may not be freed, depending on dangling references or other things, so make sure you don't have tables or other stack-referencing items currently alive or referenced that you want to be collected. .. code-block:: cpp :caption: function: make a table sol::table create_table(int narr = 0, int nrec = 0); template sol::table create_table(int narr, int nrec, Key&& key, Value&& value, Args&&... args); template sol::table create_table_with(Args&&... args); static sol::table create_table(lua_State* L, int narr = 0, int nrec = 0); template static sol::table create_table(lua_State* L, int narr, int nrec, Key&& key, Value&& value, Args&&... args); Creates a table. Forwards its arguments to :ref:`table::create`. .. _standard lua libraries: http://www.lua.org/manual/5.3/manual.html#6 .. _luaL_requiref: https://www.lua.org/manual/5.3/manual.html#luaL_requiref .. _Eric (EToreo) for the suggestion on this one: https://github.com/ThePhD/sol2/issues/90