seo优化师培训,长沙官网优化公司,沭阳金地建设网站,电子商城系统开发模块文章目录 1、Lua和C交互2、基础练习2.1、加载Lua脚本并传递参数2.2、加载脚本到stable#xff08;包#xff09;2.3、Lua调用c语言接口2.4、Lua实现面向对象2.5、向脚本中注册c的类 1、Lua和C交互 1、lua和c交互机制是基于一个虚拟栈#xff0c;C和lua之间的所有数据交互都通… 文章目录 1、Lua和C交互2、基础练习2.1、加载Lua脚本并传递参数2.2、加载脚本到stable包2.3、Lua调用c语言接口2.4、Lua实现面向对象2.5、向脚本中注册c的类 1、Lua和C交互 1、lua和c交互机制是基于一个虚拟栈C和lua之间的所有数据交互都通过这个虚拟栈来完成无论何时C想从lua中调用一个值被请求的值将会被压入栈C想要传递一个值给Lua首选将整个值压栈然后就可以在Lua中调用。 2、lua中提供正向和反向索引区别在于证书永远是栈底负数永远是栈顶。 2、基础练习 编译指令g test.cpp -o test -llua -ldl #include iostream
#include string.h
using namespace std;extern C
{
#include lua.h
#include lauxlib.h
#include lualib.h
}// g test.cpp -o test -llua -ldl
int main()
{//1.创建一个state // luaL_newstate返回一个指向堆栈的指针lua_State *L luaL_newstate();//2.入栈操作 lua_pushstring(L, hello world);lua_pushnumber(L, 200);//3.取值操作 if (lua_isstring(L, 1)) { //判断是否可以转为string cout lua_tostring(L, 1) endl; //转为string并返回 }if (lua_isnumber(L, 2)) {cout lua_tonumber(L, 2) endl;}//4.关闭state lua_close(L);return 0;
}2.1、加载Lua脚本并传递参数 编译指令g test.cpp -o test -llua -ldl 函数说明1、函数用于将Lua脚本加载到Lua虚拟机中并进行编译
luaL_loadbuffer(L,s,sz,n)lua_State *LLua状态对象表示Lua虚拟机的运行实例。const char *buff指向Lua脚本内容的字符串。size_t szLua脚本内容的长度。const char *name可选参数用于给脚本设置一个名称便于调试和错误消息的输出。返回值不为0表示有错误2、函数用于调用Lua函数并处理其执行过程中可能发生的错误
lua_pcall(L,n,r,f)lua_State *LLua状态对象表示Lua虚拟机的运行实例。int nargs传递给Lua函数的参数数量。int nresults期望的返回值数量。int errfunc错误处理函数在调用栈中的索引。返回值不为0表示有错误3、函数用于从全局环境中获取一个全局变量并将其值压入Lua栈顶
int lua_getglobal(lua_State *L, const char *name)lua_State *LLua状态对象表示Lua虚拟机的运行实例。const char *name要获取的全局变量的名称。4、函数用于将一个数字lua_Number类型压入Lua栈顶
void lua_pushnumber(lua_State *L, lua_Number n)lua_State *LLua状态对象表示Lua虚拟机的运行实例。lua_Number n要压入栈的数字。 执行流程 1、加载script脚本加载到lua虚拟机中 2、将脚本中的my_pow函数压入到栈顶 3、压入my_pow需要的两个参数 4、执行脚本 5、获取脚本中的返回值 #include cstdio
#include cstring
#include cmath
#include new
extern C {#include lua.h#include lualib.h#include lauxlib.h
}char const *script R(
function hello()print(hello world)
endfunction my_pow(x,y)return x^y
end
);char const *script_1 R(pkg.hello()
);int main()
{/*加载脚本并传递参数*/// 创建lua虚拟机创建虚拟栈lua_State *state luaL_newstate();// 打开lua标准库以便正常使用lua apiluaL_openlibs(state);{// 将lua脚本加载到虚拟机中并编译auto rst luaL_loadbuffer(state,script,strlen(script),hello);// 判断是否加载成功if(rst !0 ){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script faile:%s\n,msg);lua_pop(state,-1);}return -1;}// 执行加载并编译的Lua脚本if(lua_pcall(state,0,0,0)){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script faile:%s,msg);lua_pop(state,-1);}}// 从全局环境中获取一个my_pow函数压入到栈顶lua_getglobal(state,my_pow);// 判断栈顶是不是一个函数要是不是表示没有找到if(!lua_isfunction(state,-1)){printf(function named my_pow not function\n);return -1;}// 将数字参数压入Lua栈中lua_pushnumber(state,2);lua_pushnumber(state,8);rst lua_pcall(state,2,1,0);if(rst !0 ){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script faile:%s\n,msg);lua_pop(state,-1);}return -1;}if(lua_isnumber(state,-1)){lua_Number val lua_tonumber(state,-1);printf(%lf\n,val);}}lua_close(state);return 0;
}2.2、加载脚本到stable包 编译命令 g main.cpp -o main -llua -ldl #include cstdio
#include cstring
#include cmath
#include new
extern C {#include lua.h#include lualib.h#include lauxlib.h
}
char const *script R(
function hello()print(hello world)
endfunction my_pow(x,y)return x^y
end
);/* _G {helloworld function print(hello world)}_G {pkg {helloworld function print(hello world)}}pkg.helloworld()
*/char const *script_1 R(pkg.hello()
);int main()
{/*加载脚本到stable包1、生成chunk push到栈顶2、创建table设置给_G表_G[pkg] {}3、给这个table设置元表元表继承_G的访问域(__index)4、执行code chunk*/lua_State *state luaL_newstate();luaL_openlibs(state);{auto rst luaL_loadbuffer(state,script,strlen(script),helloworld);if(rst ! 0){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script faile:%s\n,msg);lua_pop(state,1);}return -1;}// 取出_G表lua_getglobal(state,_G);if(lua_istable(state,-1)){ // chunk _Glua_newtable(state); // 创建表 chunk _G new_stablelua_pushstring(state,pkg); // chunk _G new_stable pkglua_pushvalue(state,-2); // chunk _G new_stable pkg new_stablelua_rawset(state,-4); // chunk _G new_stablechar const *upvalueName lua_setupvalue(state,-3,1); // chunk _Glua_newtable(state); // chunk _G metastablelua_pushstring(state,__index); // chunk _G metastable __indexlua_pushvalue(state,-3); // chunk _G metastable __index _Glua_rawset(state,-3); // chunk _G metastablelua_pushstring(state,pkg);lua_rawget(state,-3); // chunk _G metastable pkg(table)lua_pushvalue(state,-2); // chunk _G metastable pkg(table) metastablelua_setmetatable(state,-2); // chunk _G metastable pkg(stable)lua_pop(state,3); // chunk}// 执行chunkif(lua_pcall(state,0,0,0)){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(call function chunk failed:%s\n,msg);lua_pop(state,1);}}// 加载script_1rst luaL_loadbuffer(state,script_1,strlen(script_1),script_1);if(rst ! 0){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script failed:%s\n,msg);lua_pop(state,1);}return -1;}if(lua_pcall(state,0,0,0)){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(call function chunk failed:%s\n,msg);lua_pop(state,1);}}lua_close(state);}return 0;
}2.3、Lua调用c语言接口
#include cstdio
#include cstring
#include cmath
#include new
extern C {#include lua.h#include lualib.h#include lauxlib.h
}int pow_from_c(lua_State *L)
{int param_count lua_gettop(L);if(param_count ! 2)return 0;if(lua_isinteger(L,1) lua_isinteger(L,2)){auto x lua_tointeger(L,1);auto y lua_tointeger(L,2);int rst (int)pow(x,y);lua_pushinteger(L,rst);return 1;}return 0;
}char const *script_2 R(local val pow_from_c(2,3)print(val)
);
int main()
{// lua调用c语言接口lua_State *state luaL_newstate();luaL_openlibs(state);{/*_G {pow_from_c pow_from_c}*/lua_getglobal(state,_G);lua_pushstring(state,pow_from_c);lua_pushcclosure(state,pow_from_c,0); // _G pow_from_c; closurelua_rawset(state,-3); // _Glua_pop(state,1); // _G}auto rst luaL_loadbuffer(state,script_2,strlen(script_2),script_2);if(rst ! 0){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script faile:%s\n,msg);lua_pop(state,1);}return -1;}if(lua_pcall(state,0,0,0)){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(call function chunk failed:%s\n,msg);lua_pop(state,1);}}lua_close(state);return 0;
}2.4、Lua实现面向对象
local anial_matestable {__index {walk function (self)print(self,我是walk)end,eat function (self)print(self,eat.)end,},__newindex function (object,key,value)print(assigned ..value..named ..key..but not really)end,
}function newobject()local objs {name xxxx}setmetatable(objs,anial_matestable)return objs
endlocal obj newobject()
obj.eat()
obj.walk()
obj.name abc
obj.id 02.5、向脚本中注册c的类
#include cstdio
#include cstring
#include cmath
#include new
extern C {#include lua.h#include lualib.h#include lauxlib.h
}
char const *script_3 R(local obj_1 create_game_object(1);local obj_2 create_game_object(1);local obj_3 create_game_object(2);local rst1 obj_1:equal(obj_2)local rst2 obj_1:equal(obj_3)print(rst1,;,rst2)print(..obj_1:id())
);class GameObject{
private:u_int32_t _id;
public:static size_t registy_value;
public:GameObject(u_int32_t id):_id(id){}u_int32_t id()const{return _id;}bool equal(GameObject *obj){return _id obj-id();}
};
size_t GameObject::registy_value 0;int GameObject_equal(lua_State *state){int arg_count lua_gettop(state);if(arg_count!2){return 0;}if(lua_isuserdata(state,1) lua_isuserdata(state,2)){void *userdata_self lua_touserdata(state,1);void *userdata_that lua_touserdata(state,2);GameObject *obj1 (GameObject*)userdata_self;GameObject *obj2 (GameObject*)userdata_that;auto rst obj1-equal(obj2);lua_pushboolean(state,rst);return 1;}return 0;
}int GameObject_id(lua_State* state){GameObject *this_obj (GameObject*)lua_touserdata(state,1);auto rst this_obj-id();lua_pushinteger(state,rst);return 1;
}int create_game_object(lua_State* state){auto id lua_tointeger(state,1);void *p lua_newuserdata(state,sizeof(GameObject));GameObject *obj new(p)GameObject(id);lua_rawgetp(state,LUA_REGISTRYINDEX,GameObject::registy_value);lua_setmetatable(state,-2);return 1;
}int main()
{// 怎么向脚本中注册c的类// 使用userdata/*userdata:{metadata:{__index {equal function(){},id function(){},}}}*/lua_State *state luaL_newstate();luaL_openlibs(state);{lua_getglobal(state,_G);lua_pushstring(state,create_game_object);lua_pushcclosure(state,create_game_object,0);lua_rawset(state,-3);lua_pop(state,1);lua_newtable(state);lua_pushstring(state,__index);lua_newtable(state);lua_pushstring(state,equal);lua_pushcclosure(state,GameObject_equal,0);lua_rawset(state,-3);lua_pushstring(state,id);lua_pushcclosure(state,GameObject_id,0);lua_rawset(state,-3);lua_rawset(state,-3);lua_rawsetp(state,LUA_REGISTRYINDEX,GameObject::registy_value);auto rst luaL_loadbuffer(state,script_3,strlen(script_3),oop);if(rst ! 0){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script failed:%s\n,msg);lua_pop(state,1);}return -1;}// 执行if(lua_pcall(state,0,0,0)){if(lua_isstring(state,-1)){auto msg lua_tostring(state,-1);printf(load script failed:%s\n,msg);lua_pop(state,1);}}}lua_close(state);return 0;
}
