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new implementation for `require' (with templates)
This commit is contained in:
Roberto Ierusalimschy
parent
62dd4cbe91
commit
391c5459cb
175
lbaselib.c
175
lbaselib.c
@ -1,5 +1,5 @@
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/*
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** $Id: lbaselib.c,v 1.66 2002/04/09 20:19:06 roberto Exp roberto $
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** $Id: lbaselib.c,v 1.67 2002/04/12 19:57:29 roberto Exp roberto $
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** Basic library
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** See Copyright Notice in lua.h
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*/
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@ -200,6 +200,23 @@ static int luaB_next (lua_State *L) {
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}
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static int luaB_nexti (lua_State *L) {
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lua_Number i = lua_tonumber(L, 2);
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luaL_check_type(L, 1, LUA_TTABLE);
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if (i == 0) { /* `for' start? */
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lua_getglobal(L, "nexti"); /* return generator, */
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lua_pushvalue(L, 1); /* state, */
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lua_pushnumber(L, 1); /* and initial value */
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return 3;
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}
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else { /* `for' step */
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lua_pushnumber(L, i+1); /* next value */
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lua_rawgeti(L, 1, i);
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return (lua_isnil(L, -1)) ? 0 : 2;
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}
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}
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static int passresults (lua_State *L, int status, int oldtop) {
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if (status == 0) {
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int nresults = lua_gettop(L) - oldtop;
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@ -259,58 +276,6 @@ static int luaB_assert (lua_State *L) {
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}
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#define LUA_PATH "LUA_PATH"
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#define LUA_PATH_SEP ";"
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#ifndef LUA_PATH_DEFAULT
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#define LUA_PATH_DEFAULT "./"
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#endif
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static int luaB_require (lua_State *L) {
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const char *path;
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luaL_check_string(L, 1);
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lua_settop(L, 1);
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lua_getglobal(L, LUA_PATH); /* get path */
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if (lua_isstring(L, 2)) /* is LUA_PATH defined? */
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path = lua_tostring(L, 2);
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else { /* LUA_PATH not defined */
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lua_pop(L, 1); /* pop old global value */
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path = getenv(LUA_PATH); /* try environment variable */
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if (path == NULL) path = LUA_PATH_DEFAULT; /* else use default */
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lua_pushstring(L, path);
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lua_pushvalue(L, -1); /* duplicate to leave a copy on stack */
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lua_setglobal(L, LUA_PATH);
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}
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lua_pushvalue(L, 1); /* check package's name in book-keeping table */
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lua_gettable(L, lua_upvalueindex(1));
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if (!lua_isnil(L, -1)) /* is it there? */
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return 0; /* package is already loaded */
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else { /* must load it */
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for (;;) { /* traverse path */
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int res;
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int l = strcspn(path, LUA_PATH_SEP); /* find separator */
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lua_pushlstring(L, path, l); /* directory name */
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lua_pushvalue(L, 1); /* package name */
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lua_concat(L, 2); /* concat directory with package name */
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res = lua_dofile(L, lua_tostring(L, -1)); /* try to load it */
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lua_settop(L, 2); /* pop string and eventual results from dofile */
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if (res == 0) break; /* ok; file done */
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else if (res != LUA_ERRFILE)
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lua_error(L, NULL); /* error running package; propagate it */
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if (*(path+l) == '\0') /* no more directories? */
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luaL_verror(L, "could not load package `%.20s' from path `%.200s'",
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lua_tostring(L, 1), lua_tostring(L, 2));
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path += l+1; /* try next directory */
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}
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}
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lua_pushvalue(L, 1);
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lua_pushnumber(L, 1);
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lua_settable(L, lua_upvalueindex(1)); /* mark it as loaded */
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return 0;
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}
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static int aux_unpack (lua_State *L, int arg) {
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int n, i;
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luaL_check_type(L, arg, LUA_TTABLE);
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@ -395,6 +360,104 @@ static int luaB_tostring (lua_State *L) {
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}
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/*
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** {======================================================
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** `require' function
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** =======================================================
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*/
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/* name of global that holds table with loaded packages */
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#define REQTAB "_LOADED"
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/* name of global that holds the search path for packages */
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#define LUA_PATH "LUA_PATH"
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#ifndef LUA_PATH_SEP
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#define LUA_PATH_SEP ';'
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#endif
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#ifndef LUA_PATH_DEFAULT
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#define LUA_PATH_DEFAULT "?.lua"
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#endif
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static const char *getpath (lua_State *L) {
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const char *path;
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lua_getglobal(L, LUA_PATH); /* try global variable */
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path = lua_tostring(L, -1);
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if (path) return path;
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path = getenv(LUA_PATH); /* else try environment variable */
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if (path) return path;
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return LUA_PATH_DEFAULT; /* else use default */
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}
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static const char *nextpath (lua_State *L, const char *path) {
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const char *l;
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if (*path == '\0') return NULL; /* no more pathes */
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if (*path == LUA_PATH_SEP) path++; /* skip separator */
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l = strchr(path, LUA_PATH_SEP); /* find next separator */
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if (l == NULL) l = path+strlen(path);
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lua_pushlstring(L, path, l - path); /* directory name */
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return l;
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}
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static void composename (lua_State *L) {
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const char *path = lua_tostring(L, -1);
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const char *wild = strchr(path, '?');
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if (wild == NULL) return; /* no wild char; path is the file name */
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lua_pushlstring(L, path, wild - path);
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lua_pushvalue(L, 1); /* package name */
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lua_pushstring(L, wild + 1);
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lua_concat(L, 3);
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}
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static int luaB_require (lua_State *L) {
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const char *path;
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int status = LUA_ERRFILE; /* not found (yet) */
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luaL_check_string(L, 1);
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lua_settop(L, 1);
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lua_pushvalue(L, 1);
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lua_setglobal(L, "_REQUIREDNAME");
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lua_getglobal(L, REQTAB);
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if (!lua_istable(L, 2)) lua_error(L, REQTAB " is not a table");
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path = getpath(L);
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lua_pushvalue(L, 1); /* check package's name in book-keeping table */
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lua_gettable(L, 2);
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if (!lua_isnil(L, -1)) /* is it there? */
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return 0; /* package is already loaded */
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else { /* must load it */
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while (status == LUA_ERRFILE && (path = nextpath(L, path)) != NULL) {
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composename(L);
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status = lua_dofile(L, lua_tostring(L, -1)); /* try to load it */
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lua_settop(L, 3); /* pop string and eventual results from dofile */
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}
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}
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switch (status) {
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case 0: {
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lua_pushvalue(L, 1);
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lua_pushboolean(L, 1);
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lua_settable(L, 2); /* mark it as loaded */
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return 0;
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}
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case LUA_ERRFILE: { /* file not found */
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luaL_verror(L, "could not load package `%.20s' from path `%.200s'",
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lua_tostring(L, 1), lua_tostring(L, 3));
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}
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default: { /* error loading package */
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lua_error(L, NULL);
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return 0; /* to avoid warnings */
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}
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}
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}
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/* }====================================================== */
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static const luaL_reg base_funcs[] = {
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{LUA_ALERT, luaB__ALERT},
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{LUA_ERRORMESSAGE, luaB__ERRORMESSAGE},
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@ -402,6 +465,7 @@ static const luaL_reg base_funcs[] = {
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{"metatable", luaB_metatable},
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{"globals", luaB_globals},
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{"next", luaB_next},
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{"nexti", luaB_nexti},
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{"print", luaB_print},
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{"tonumber", luaB_tonumber},
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{"tostring", luaB_tostring},
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@ -417,6 +481,7 @@ static const luaL_reg base_funcs[] = {
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{"loadstring", luaB_loadstring},
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{"dofile", luaB_dofile},
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{"dostring", luaB_dostring},
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{"require", luaB_require},
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{NULL, NULL}
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};
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@ -511,10 +576,8 @@ static void base_open (lua_State *L) {
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LUALIB_API int lua_baselibopen (lua_State *L) {
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base_open(L);
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co_open(L);
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/* `require' needs an empty table as upvalue */
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lua_newtable(L);
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lua_pushcclosure(L, luaB_require, 1);
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lua_setglobal(L, "require");
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lua_setglobal(L, REQTAB);
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return 0;
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}
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