oo lua binding example

ldiriterator.c

#define LUA_LIB

#include <windows.h>
#include "lua.h"
#include "lauxlib.h"
#include "ldiriterator.h"

typedef struct DirectoryIterator
{
  HANDLE handle;
  BOOL last_result;
  WIN32_FIND_DATA find_data;
} DirectoryIterator;

static int newDirectoryIterator(lua_State *L)
{
  DirectoryIterator *p;
  const char *s = luaL_checkstring(L, 1);
  
  HANDLE handle;
  WIN32_FIND_DATA find_data;

  handle = FindFirstFileA(s, &find_data);
  if (handle == INVALID_HANDLE_VALUE)
  {
    lua_pushnil(L);
    return 1;
  }
  
  p = (DirectoryIterator *) lua_newuserdata(L, sizeof(DirectoryIterator));
  
  luaL_getmetatable(L, "LuaBook.directoryiterator");
  lua_setmetatable(L, -2);
      
  p->handle = handle;
  p->last_result = TRUE;
  memcpy(&p->find_data, &find_data, sizeof(find_data));
  
  return 1;
}

static int nextEntry(lua_State *L)
{
  void *ud;
  DirectoryIterator *p;
  
  ud = luaL_checkudata(L, 1, "LuaBook.directoryiterator");
  luaL_argcheck(L, ud != NULL, 1, "`directoryiterator' expected");
  p = (DirectoryIterator *) ud;
      
  if (p->last_result)
    lua_pushstring(L, p->find_data.cFileName);    
  else
    lua_pushnil(L);
  
  p->last_result = FindNextFile(p->handle, &p->find_data);
  
  return 1;
}

static int closeIterator(lua_State *L)
{
  DirectoryIterator *p = (DirectoryIterator *) luaL_checkudata(L, 1, "LuaBook.directoryiterator");
  FindClose(p->handle);  

  return 0;
}

static const struct luaL_reg directoryiterator_f [] =
{
  {"new", newDirectoryIterator},
  {NULL, NULL}
};

static const struct luaL_reg directoryiterator_m [] =
{
  {"next", nextEntry},
  {"__gc", closeIterator},
  {NULL, NULL}
};

LUALIB_API int luaopen_diriterator(lua_State *L)
{
  luaL_newmetatable(L, "LuaBook.directoryiterator");
  
  lua_pushstring(L, "__index");
  lua_pushvalue(L, -2);
  lua_settable(L, -3);
  
  luaL_openlib(L, NULL, directoryiterator_m, 0);
  luaL_openlib(L, "directoryiterator", directoryiterator_f, 0);

  return 1;
}

ldiriterator.h

LUALIB_API int luaopen_diriterator(lua_State *L);

linit.c

/*
** $Id: linit.c,v 1.14.1.1 2007/12/27 13:02:25 roberto Exp $
** Initialization of libraries for lua.c
** See Copyright Notice in lua.h
*/


#define linit_c
#define LUA_LIB

#include "lua.h"

#include "lualib.h"
#include "lauxlib.h"

#include "ldiriterator.h"

static const luaL_Reg lualibs[] = {
  {"", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
  {LUA_TABLIBNAME, luaopen_table},
  {LUA_IOLIBNAME, luaopen_io},
  {LUA_OSLIBNAME, luaopen_os},
  {LUA_STRLIBNAME, luaopen_string},
  {LUA_MATHLIBNAME, luaopen_math},
  {LUA_DBLIBNAME, luaopen_debug},
  {"diriterator", luaopen_diriterator},
  {NULL, NULL}
};


LUALIB_API void luaL_openlibs (lua_State *L) {
  const luaL_Reg *lib = lualibs;
  for (; lib->func; lib++) {
    lua_pushcfunction(L, lib->func);
    lua_pushstring(L, lib->name);
    lua_call(L, 1, 0);
  }
}