C interacts with Lua to pass the C struct form table to Lua

Overview

The previous LUA-C interaction function Registration describes how to register C functions with Lua for use in Lua.
When the C-provided interface for fetching data is called in Lua, how does C convert multiple struct types to LUA's nested table types?

Here is an example to illustrate the C data type

typedef struct STUDENT
{
	int age	 ;		< age	
	int	 grade;		< grade
	Char name[32];	< name
}student;

typedef struct  School
{
	char phone[32];		< telephone
	int  totalpeople;	///< total number
}school;

define an interface to get data

int Get_student_info (student* p_student)
{
	assert (NULL! = p_student);
	P_student->age = 8;
	P_student->grade = 3;
	strncpy (P_student->name, "xiaoming", +);
	
	return 0;
}

int Get_school_info (school* p_school)
{
	assert (NULL! = p_school);
	P_school->totalpeople = $;
	strncpy (P_school->phone, "1008611", +);

	return 0;
}

interface implementations registered to LUA calls

#define JL_GET_ARRAY_MAX///< Get the maximum number of properties at once #define Jl_key_buf_max///<
	Keyword maximum cache length static void Format_student (Lua_state *l) {student student_info;
	memset (&student_info, 0, sizeof (student_info));
	int ret = Get_student_info (&student_info);	
	if (0! = ret) {assert (false);
		} else {lua_newtable (L);
		Lua_pushstring (L, student_info.name);
	
		Lua_setfield (L,-2, "name");
		Lua_pushinteger (L, student_info.age);
		
		Lua_setfield (L,-2, "age");
		Lua_pushinteger (L, Student_info.grade);
		
		Lua_setfield (L,-2, "grade");
		Nested student table into the parameter table lua_pushstring (L, "student"); Lua_insert (L,-2); /* Student Table */lua_settable (L,-3);
	/* Param.student = student */}} static void Format_school (Lua_state *l) {School school_info;
	memset (&school_info, 0, sizeof (school_info));
	int ret = Get_school_info (&school_info);	
	if (0! = ret) {assert (false);
		} else {lua_newtable (L); Lua_pushstring (L, School_infO.phone);
	
		Lua_setfield (L,-2, "phone");
		Lua_pushinteger (L, school_info.totalpeople);
				
		Lua_setfield (L,-2, "totalpeople");
		Nested school table into the parameter table lua_pushstring (L, "school"); Lua_insert (L,-2); /* School Table */lua_settable (L,-3); /* Param.school = School */}}//Here we register the function parameter for LUA to the array {"School", "student"} int lua_get_info (Lua_state *l) {lual_checkt Ype (L, 1, lua_ttable); Detects if the pass-through is table int array_len = Lua_rawlen (L, 1);
	The length of the array char Keys[jl_get_array_max][jl_key_buf_max] = {0}; int Len_max = (Array_len <= jl_get_array_max)?

	Array_len:jl_get_array_max;
	int idx = 1;
	int keys_num = 0;

		Take element for (int i = 0; i < Len_max; i++) {Lua_rawgeti (L, 1, idx++);
		size_t Tmp_len = 0;

		Const char* P_STR = lual_checklstring (L,-1, &tmp_len);
			if ((0 < Tmp_len) && (Tmp_len < Jl_key_buf_max)) {strcpy (Keys[keys_num], p_str);
		Keys_num + = 1;
	} lua_pop (L, 1);

	}//Return to Table lua_newtable (L); for (int k = 0; k < keys_num; ++k{if (0 = = strcmp (Keys[k], "school")) {Format_school (L);//Spell School Table} else if (0 = = strcmp (Keys[k], "s Tudent ")) {format_student (L);//Spell Student Table}} return 1;
 Indicates that a parameter is returned}

test code in LUA

Local B_APP_API = require (APP_API)
local param = b_app_api.get_info{"school", "student"}
assert (param ~= nil) C3/>print (Param.student.age, Param.student.grade, param.student.name)
print (Param.school.phone, param.school.totalPeople)

Result:
[Lua-print]: 8	3	xiaoming
[lua-print]: 1008611	500