new metamethods for '__pairs' and '__ipairs'

This commit is contained in:
Roberto Ierusalimschy 2007-10-17 15:26:39 -02:00
parent b7fa64565a
commit ab09732986

View File

@ -1,5 +1,5 @@
/*
** $Id: lbaselib.c,v 1.197 2007/02/09 12:40:21 roberto Exp roberto $
** $Id: lbaselib.c,v 1.198 2007/06/21 13:48:04 roberto Exp roberto $
** Basic library
** See Copyright Notice in lua.h
*/
@ -223,6 +223,22 @@ static int luaB_type (lua_State *L) {
}
static int pairsmeta (lua_State *L, const char *method, int iszero) {
if (!luaL_getmetafield(L, 1, method)) { /* no metamethod? */
luaL_checktype(L, 1, LUA_TTABLE); /* argument must be a table */
lua_pushvalue(L, lua_upvalueindex(1)); /* will return generator, */
lua_pushvalue(L, 1); /* state, */
if (iszero) lua_pushinteger(L, 0); /* and initial value */
else lua_pushnil(L);
}
else {
lua_pushvalue(L, 1); /* argument 'self' to metamethod */
lua_call(L, 1, 3); /* get 3 values from metamethod */
}
return 3;
}
static int luaB_next (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
lua_settop(L, 2); /* create a 2nd argument if there isn't one */
@ -236,11 +252,7 @@ static int luaB_next (lua_State *L) {
static int luaB_pairs (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
lua_pushvalue(L, lua_upvalueindex(1)); /* return generator, */
lua_pushvalue(L, 1); /* state, */
lua_pushnil(L); /* and initial value */
return 3;
return pairsmeta(L, "__pairs", 0);
}
@ -255,11 +267,7 @@ static int ipairsaux (lua_State *L) {
static int luaB_ipairs (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
lua_pushvalue(L, lua_upvalueindex(1)); /* return generator, */
lua_pushvalue(L, 1); /* state, */
lua_pushinteger(L, 0); /* and initial value */
return 3;
return pairsmeta(L, "__ipairs", 1);
}