/* vim: set et sw=3 tw=0 fo=croqlaw cino=t0: * * Luaxx, the C++ Lua wrapper library. * Copyright (c) 2006-2008 Matthew Nicholson * * 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 use, copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of 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 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include #include #define LOG std::cout /** @file * Luaxx implementation file. */ namespace lua { void StackDump(lua_State *L) { int i; int top = lua_gettop(L); for (i = 1; i <= top; i++) /* repeat for each level */ { int t = lua_type(L, i); LOG<on the stack. This can * confuse lua::state::next(); * * @returns the indicated value from the stack or the default value if the * conversion fails */ template<> std::string state::as(std::string default_value, int index) { if (lua_isstring(L, index)) { size_t len; const char *str = lua_tolstring(L, index, &len); return std::string(str, len); } else return default_value; } /** Check an argument of the current function. * @param narg the argument number to check * * This function will throw a lua error if there is no argument at the * given position. * * @note This function is meant to be called from with in a lua::cfunction. * The error throw is internal to the lua interpreter. When compiled as * C++, a C++ exception is thrown, so the stack is properly unwound. This * exception is not meant to be caught. */ state& state::check(int narg) { luaL_checkany(L, narg); return *this; } #ifndef lua_Integer_int /** Check an argument of the current function. * @param i the int to hold the returned value * @param narg the argument number to check * * This function checks if the given argument number is an int. * * @note This function is meant to be called from with in a * lua::cfunction. The error throw is internal to the lua intrepeter. * When compiled as C++, a C++ exception is thrown, so the stack is * properly unwound. This exception is not meant to be caught. */ state& state::check(int& i, int narg) { i = luaL_checkint(L, narg); return *this; } #endif /** Check an argument of the current function. * @param i the lua::integer (lua_Integer) to hold the returned value * @param narg the argument number to check * * This function checks if the given argument number is an integer. * * @note This is different from lua::check(int(), ...). It returns a * lua::integer (lua_Integer), which may not be an int. * * @note This function is meant to be called from with in a * lua::cfunction. The error throw is internal to the lua intrepeter. * When compiled as C++, a C++ exception is thrown, so the stack is * properly unwound. This exception is not meant to be caught. */ state& state::check(integer& i, int narg) { i = luaL_checkinteger(L, narg); return *this; } #ifndef lua_Integer_long /** Check an argument of the current function. * @param l the long to hold the returned value * @param narg the argument number to check * * This function checks if the given argument number is a long. * * @note This function is meant to be called from with in a * lua::cfunction. The error throw is internal to the lua intrepeter. * When compiled as C++, a C++ exception is thrown, so the stack is * properly unwound. This exception is not meant to be caught. */ state& state::check(long& l, int narg) { l = luaL_checklong(L, narg); return *this; } #endif /** Check an argument of the current function. * @param s the string to hold the returned value * @param narg the argument number to check * * This function checks if the given argument number is a string. * * @note This function is meant to be called from with in a * lua::cfunction. The error throw is internal to the lua intrepeter. * When compiled as C++, a C++ exception is thrown, so the stack is * properly unwound. This exception is not meant to be caught. */ state& state::check(std::string& s, int narg) { const char* c; size_t l; c = luaL_checklstring(L, narg, &l); s.assign(c, l); return *this; } /** Check an argument of the current function. * @param n the lua::number (lua_Number) to hold the returned value * @param narg the argument number to check * * This function checks if the given argument number is a lua::number * (lua_Number, a double by default). * * @note This function is meant to be called from with in a lua::cfunction. * The error throw is internal to the lua interpreter. When compiled as * C++, a C++ exception is thrown, so the stack is properly unwound. This * exception is not meant to be caught. */ state& state::check(number& n, int narg) { n = luaL_checknumber(L, narg); return *this; } #if 0 /** [specialization] Generate a Lua error (T = std::string). */ template<> void state::error(const std::string& message) { push(message); lua_error(L); } #endif /** Call a lua function. * @param nargs the number of args to pass to the function * @param nresults the number of values to return from the function * @param on_error A stack index where the error handling function is * stored. * @note The error handling function must be pushed in the stack * before the function to be called and its arguments. * @returns a reference to this lua::state */ state& state::pcall(int nargs, int nresults, int on_error) { throw_error(lua_pcall(L, nargs, nresults, on_error)); return *this; } /** Call a lua function in unprotected mode. * @param nargs the number of args to pass to the function * @param nresults the number of values to return from the function * stored. * @note If there is an error in the call the program will terminate. * @returns a reference to this lua::state */ state& state::call(int nargs, int nresults) { lua_call(L, nargs, nresults); return *this; } /** Ensure the stack is at least the given size. * @param size the size to use * * If the stack is smaller than the given size, it will grow to the * specified size. * * @exception lua::exception Thrown if the operation fails. * @returns a reference to this lua::state */ state& state::checkstack(int size) { if (!lua_checkstack(L, size)) throw lua::exception("Error growing the stack"); return *this; } /** Set a new index as the top of the stack. * @param index the index to use as the new top * @note If the previous top was higher than the new one, top values * are discarded. Otherwise this function pushs nils on to the stack * to get the proper size. * @returns a reference to this lua::state */ state& state::settop(int index) { lua_settop(L, index); return *this; } /** Get the number of elements in the stack. * @note This value is also the index of the top element. * @returns the number of elements in the stack */ int state::gettop() { return lua_gettop(L); } /** Get the number of elements in the stack. * @note This value is also the index of the top element. * @returns the number of elements in the stack */ int state::size() { return lua_gettop(L); } /** Check if the stack is empty. * @returns true if the stack is empty, false otherwise */ bool state::empty() { return !lua_gettop(L); } /** Move the top element to the given index. * @param index the index to insert at * @note All elements on top of the given index are shifted up to open * space for this element. * @returns a reference to this lua::state */ state& state::insert(int index) { lua_insert(L, index); return *this; } /** Replace the given index with the top element. * @param index the index to replae * @returns a reference to this lua::state */ state& state::replace(int index) { lua_replace(L, index); return *this; } /** Remove the given index from the stack. * @param index the index to remove * @note Elements are shifted down to fill in the empty spot. * @returns a reference to this lua::state */ state& state::remove(int index) { lua_remove(L, index); return *this; } /** Remove the given number of elemens from the stack. * @param elements the number of elements to remove * @returns a reference to this lua::state */ state& state::pop(int elements) { lua_pop(L, elements); return *this; } /** Push a copy of the element at the given index to the top of the * stack. * @param index the index of the element to copy * @returns a reference to this lua::state */ state& state::pushvalue(int index) { lua_pushvalue(L, index); return *this; } /** Create a new table on the stack. * @returns a reference to this lua::state */ state& state::newtable() { lua_newtable(L); return *this; } /** Create a new metatable and add it to the registry. * @param tname the name to use for the new metatable in the registry * * This function creates a new metatable and adds it to the registry * with the given key. This function also pushes the new metatable * onto the stack. * * @note Regardless of the return value, the new metatable is always pushed * on to the stack. * * @return true if a new metatable was created, false if the registry * alread has a key with the given name. */ bool state::newmetatable(const std::string& tname) { return luaL_newmetatable(L, tname.c_str()); } /** Create a new userdatum on the stack. * @param nbytes the size of the new userdatum * @return a pointer to the new userdatum */ void* state::newuserdata(size_t nbytes) { return lua_newuserdata(L, nbytes); } /** Get a value from a table on the stack. * @param index the index the table is stored at * * This function gets a value from the table at the given index and * pushes it onto the stack. * * @note You should have already pushed the key used to reference this * value onto the stack before calling this function. * * @returns a reference to this lua::state */ state& state::gettable(int index) { lua_gettable(L, index); return *this; } /** Get a value from a table on the stack. * @param k the key * @param index the index the table is stored at * * This function gets a value from the table at the given index and * pushes it onto the stack. * * @returns a reference to this lua::state */ state& state::getfield(const std::string& k, int index) { lua_getfield(L, index, k.c_str()); return *this; } /** Set a value in a table. * @param index the index the table is stored at * * This function sets a value in a table stored at the given index. * * @note The key and value to be used should have already been pushed * on the stack in that order. * * @returns a reference to this lua::state */ state& state::settable(int index) { lua_settable(L, index); return *this; } /** Set a field in a table. * @param k the key * @param index the index the table is stored at * * This function sets a value in a table stored at the given index. * * @note The value to be used should be on the top of the stack. * * @returns a reference to this lua::state */ state& state::setfield(const std::string& k, int index) { lua_setfield(L, index, k.c_str()); return *this; } /** Get the metatable associated with the given registry entry. * @param tname the name in the registry * * This function gets the metatable associated with the given key in * the registry. The resulting metatable is pushed onto the stack. * * @note This function uses luaL_getmetatable() internally. * * @returns a reference to this lua::state */ state& state::getmetatable(const std::string& tname) { luaL_getmetatable(L, tname.c_str()); return *this; } /** Get the metatable of the value at the given index. * @param index the index the value is stored at * * This function pushes on to the stack the metatabe of the value at * the given index. * * @note This function uses lua_getmetatable() internally. * * @returns false if the value at the given index does not have a * metatable or if the index is not valid */ bool state::getmetatable(int index) { return lua_getmetatable(L, index); } /** Get the next key value pair from a table on the stack. * @param index the stack index the table is at * * This function pops a key from the stack and pushes the next key * value pair to the stack. The key will be stored at index -2 and * the value will be at index -1. The key is expected to be on the * top of the stack. * * @note While traversing a table, do not call * lua::state::to(std::string()) directly on a key, unless you know * that the key is actually a string. lua::state::to(std::string()) * changes the value at the given index; this confuses the next call * to lua::state::next(). * * While Loop Example: * @code * while(L.next() != 0) { * // do stuff * L.pop(); * } * @endcode * * For Loop Example: * @code * for(L.push(lua::nil()); L.next(); L.pop()) { * // do stuff * } * @endcode * * @returns true as long as there are remaining items in the table */ bool state::next(int index) { return lua_next(L, index); } /** Load a global symbol onto the stack. * @param name the name of the global to load * * This function loads a global symbol onto the stack from the lua * state. * * @returns a reference to this lua::state */ state& state::getglobal(const std::string& name) { lua_getglobal(L, name.c_str()); return *this; } /** Set a global symbol. * @param name the name of the global to set * * This function sets/creates a global symbol from the value above it * on the stack. * * @note You should have pushed the value of the symbol onto the stack * before calling this function. * * @returns a reference to this lua::state */ state& state::setglobal(const std::string& name) { lua_setglobal(L, name.c_str()); return *this; } /** Load a file as a Lua chunk. * @param filename the name of the file to load * @returns a reference to this lua::state */ state& state::loadfile(const std::string& filename) { throw_error(luaL_loadfile(L, filename.c_str())); return *this; } /** Load a string as a Lua chunk. * @param s the string to load * @returns a reference to this lua::state */ state& state::loadstring(const std::string& s) { throw_error(luaL_loadstring(L, s.c_str())); return *this; } /** Get the length of a value on the stack. * @param index the index the value is stored at * @returns the length of the indicated value */ size_t state::objlen(int index) { return lua_rawlen(L, index); } /** Get the value at index as a bool. * @param boolean where to store the value * @param index the index to get * @note This function does \em not pop the value from the stack. * @todo Instead of throwing an exception here, we may just return an * error code. * @throws lua::bad_conversion if the value on the stack could not be * converted to the indicated type * @returns a reference to this lua::state */ template<> state& state::to(bool& boolean, int index) { if (lua_isboolean(L, index)) boolean = lua_toboolean(L, index); else throw bad_conversion("Cannot convert non 'boolean' value to bool"); return *this; } /** Get the value at index as a string. * @param string where to store the value * @param index the index to get * @note This function does \em not pop the value from the stack. * @todo Instead of throwing an exception here, we may just return an * error code. * * @note lua::state::to(std::string()) will convert the value at the * indicated index to a string on the stack. This can * confuse lua::state::next(); * * @throws lua::bad_conversion if the value on the stack could not be * converted to the indicated type * @returns a reference to this lua::state */ template<> state& state::to(std::string& string, int index) { if (lua_isstring(L, index)) { size_t len; const char *str = lua_tolstring(L, index, &len); string.replace(0, std::string::npos, str, len); } else throw bad_conversion("Cannot convert value to string"); return *this; } /** Get the value at index as a bool. * @param default_value this value is returned if the conversion fails * @param index the index to get * @note This function does \em not pop the value from the stack. * @returns the indicated value from the stack or the default value if the * conversion fails */ template<> bool state::as(bool default_value, int index) { if (lua_isboolean(L, index)) return lua_toboolean(L, index); else return default_value; } /** [specialization] Get the value at index as a bool (T = bool). */ template<> bool state::as(int index) { if (lua_isboolean(L, index)) return lua_toboolean(L, index); else throw bad_conversion("Cannot convert non 'boolean' value to bool"); } /** [specialization] Get the value at index as a string (T = std::string). * @note lua::state::as(std::string()) will convert the value at the * indicated index to a string on the stack. This can confuse * lua::state::next(); */ template<> std::string state::as(int index) { if (lua_isstring(L, index)) { size_t len; const char *str = lua_tolstring(L, index, &len); return std::string(str, len); } else throw bad_conversion("Cannot convert value to string"); } /** [specialization] Check if the given index is a nil (T = lua::nil). */ template<> bool state::is(int index) { return lua_isnil(L, index); } /** [specialization] Check if the given index is a boolean (T = bool). */ template<> bool state::is(int index) { return lua_isboolean(L, index); } /** [specialization] Check if the given index is a string (T = std::string). */ template<> bool state::is(int index) { return lua_isstring(L, index); } /** [specialization] Check if the given index is a table (T = lua::table). */ template<> bool state::is(int index) { return lua_istable(L, index); } /** [specialization] Check if the given index is a C function (T = * lua::cfunction). */ template<> bool state::is(int index) { return lua_iscfunction(L, index); } /** [specialization] Check if the given index is a function (T = * lua::function). */ template<> bool state::is(int index) { return lua_isfunction(L, index); } /** [specialization] Check if the given index is userdata (T = * lua::userdata). */ template<> bool state::is(int index) { return lua_isuserdata(L, index); } /** [specialization] Check if the given index is light userdata (T = * lua::lightuserdata). */ template<> bool state::is(int index) { return lua_islightuserdata(L, index); } }