factoring out common code in 'module' and 'luaL_openlib'

This commit is contained in:
Roberto Ierusalimschy
2010-05-31 13:34:19 -03:00
parent bd619b9311
commit 2c1a5d678d
3 changed files with 35 additions and 29 deletions

View File

@@ -1,5 +1,5 @@
/*
** $Id: lauxlib.c,v 1.212 2010/05/18 17:21:24 roberto Exp roberto $
** $Id: lauxlib.c,v 1.213 2010/05/18 17:32:19 roberto Exp roberto $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/
@@ -639,6 +639,9 @@ LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
}
/*
** Count number of elements in a luaL_Reg list.
*/
static int libsize (const luaL_Reg *l) {
int size = 0;
for (; l && l->name; l++) size++;
@@ -646,23 +649,34 @@ static int libsize (const luaL_Reg *l) {
}
/*
** Find or create a module table with a given name. The function
** first looks at the _LOADED table and, if that fails, try a
** global variable with that name. In any case, leaves on the stack
** the module table.
*/
LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname,
int sizehint) {
luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */
lua_getfield(L, -1, modname); /* get _LOADED[modname] */
if (!lua_istable(L, -1)) { /* not found? */
lua_pop(L, 1); /* remove previous result */
/* try global variable (and create one if it does not exist) */
lua_pushglobaltable(L);
if (luaL_findtable(L, 0, modname, sizehint) != NULL)
luaL_error(L, "name conflict for module " LUA_QS, modname);
lua_pushvalue(L, -1);
lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */
}
lua_remove(L, -2); /* remove _LOADED table */
}
LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
const luaL_Reg *l, int nup) {
luaL_checkversion(L);
if (libname) {
/* check whether lib already exists */
luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);
lua_getfield(L, -1, libname); /* get _LOADED[libname] */
if (!lua_istable(L, -1)) { /* not found? */
lua_pop(L, 1); /* remove previous result */
/* try global variable (and create one if it does not exist) */
lua_pushglobaltable(L);
if (luaL_findtable(L, 0, libname, libsize(l)) != NULL)
luaL_error(L, "name conflict for module " LUA_QS, libname);
lua_pushvalue(L, -1);
lua_setfield(L, -3, libname); /* _LOADED[libname] = new table */
}
lua_remove(L, -2); /* remove _LOADED table */
luaL_pushmodule(L, libname, libsize(l)); /* get/create library table */
lua_insert(L, -(nup + 1)); /* move library table to below upvalues */
}
luaL_checkstack(L, nup, "too many upvalues");