/*
** Main operation 'ra' = #rb'.
*/
void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
const TValue *tm;
switch (ttype(rb)) {
case LUA_TTABLE: {
Table *h = hvalue(rb);
tm = fasttm(L, h->metatable, TM_LEN);
if (tm) break; /* metamethod? break switch to call it */
setivalue(ra, luaH_getn(h)); /* else primitive len */
return;
}
case LUA_TSHRSTR: {
setivalue(ra, tsvalue(rb)->shrlen);
return;
}
case LUA_TLNGSTR: {
setivalue(ra, tsvalue(rb)->u.lnglen);
return;
}
default: { /* try metamethod */
tm = luaT_gettmbyobj(L, rb, TM_LEN);
if (ttisnil(tm)) /* no metamethod? */
luaG_typeerror(L, rb, "get length of");
break;
}
}
luaT_callTM(L, tm, rb, rb, ra, 1);
}
/*
** Main function for table assignment (invoking metamethods if needed).
** Compute 't[key] = val'
*/
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* 't' is a table? */
Table *h = hvalue(t);
TValue *oldval = cast(TValue *, luaH_get(h, key));
/* if previous value is not nil, there must be a previous entry
in the table; a metamethod has no relevance */
if (!ttisnil(oldval) ||
/* previous value is nil; must check the metamethod */
((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
/* no metamethod; is there a previous entry in the table? */
(oldval != luaO_nilobject ||
/* no previous entry; must create one. (The next test is
always true; we only need the assignment.) */
(oldval = luaH_newkey(L, h, key), 1)))) {
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, oldval, val); /* assign new value to that entry */
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
}
else /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
}
/*
** Finish the table access 'val = t[key]'.
** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to
** t[k] entry (which must be nil).
*/
void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
const TValue *slot) {
int loop; /* counter to avoid infinite loops */
const TValue *tm; /* metamethod */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
if (slot == NULL) { /* 't' is not a table? */
lua_assert(!ttistable(t));
tm = luaT_gettmbyobj(L, t, TM_INDEX);
if (ttisnil(tm))
luaG_typeerror(L, t, "index"); /* no metamethod */
/* else will try the metamethod */
}
else { /* 't' is a table */
lua_assert(ttisnil(slot));
tm = fasttm(L, hvalue(t)->metatable, TM_INDEX); /* table's metamethod */
if (tm == NULL) { /* no metamethod? */
setnilvalue(val); /* result is nil */
return;
}
/* else will try the metamethod */
}
if (ttisfunction(tm)) { /* is metamethod a function? */
luaT_callTM(L, tm, t, key, val, 1); /* call it */
return;
}
t = tm; /* else try to access 'tm[key]' */
if (luaV_fastget(L,t,key,slot,luaH_get)) { /* fast track? */
setobj2s(L, val, slot); /* done */
return;
}
/* else repeat (tail call 'luaV_finishget') */
}
luaG_runerror(L, "'__index' chain too long; possible loop");
}
int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
StkId res, TMS event) {
const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
if (ttisnil(tm))
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
if (ttisnil(tm)) return 0;
luaT_callTM(L, tm, p1, p2, res, 1);
return 1;
}
/*
** Main operation for equality of Lua values; return 't1 == t2'.
** L == NULL means raw equality (no metamethods)
*/
int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
const TValue *tm;
if (ttype(t1) != ttype(t2)) { /* not the same variant? */
#ifndef _KERNEL
if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER)
return 0; /* only numbers can be equal with different variants */
else { /* two numbers with different variants */
lua_Integer i1, i2; /* compare them as integers */
return (tointeger(t1, &i1) && tointeger(t2, &i2) && i1 == i2);
}
#else /* _KERNEL */
return 0; /* numbers have only the integer variant */
#endif /* _KERNEL */
}
/* values have same type and same variant */
switch (ttype(t1)) {
case LUA_TNIL: return 1;
case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2));
#ifndef _KERNEL
case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2));
#endif /* _KERNEL */
case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
case LUA_TLCF: return fvalue(t1) == fvalue(t2);
case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2));
case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2));
case LUA_TUSERDATA: {
if (uvalue(t1) == uvalue(t2)) return 1;
else if (L == NULL) return 0;
tm = fasttm(L, uvalue(t1)->metatable, TM_EQ);
if (tm == NULL)
tm = fasttm(L, uvalue(t2)->metatable, TM_EQ);
break; /* will try TM */
}
case LUA_TTABLE: {
if (hvalue(t1) == hvalue(t2)) return 1;
else if (L == NULL) return 0;
tm = fasttm(L, hvalue(t1)->metatable, TM_EQ);
if (tm == NULL)
tm = fasttm(L, hvalue(t2)->metatable, TM_EQ);
break; /* will try TM */
}
default:
return gcvalue(t1) == gcvalue(t2);
}
if (tm == NULL) /* no TM? */
return 0; /* objects are different */
luaT_callTM(L, tm, t1, t2, L->top, 1); /* call TM */
return !l_isfalse(L->top);
}
/*
** Main function for table assignment (invoking metamethods if needed).
** Compute 't[key] = val'
*/
void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
StkId val, const TValue *oldval) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (oldval != NULL) {
Table *h = hvalue(t); /* save 't' table */
lua_assert(ttisnil(oldval));
/* must check the metamethod */
if ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
/* no metamethod; is there a previous entry in the table? */
(oldval != luaO_nilobject ||
/* no previous entry; must create one. (The next test is
always true; we only need the assignment.) */
(oldval = luaH_newkey(L, h, key), 1))) {
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, cast(TValue *, oldval), val);
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
}
else { /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
}
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
if (luaV_fastset(L, t, key, oldval, luaH_get, val))
return; /* done */
/* else loop */
}
luaG_runerror(L, "settable chain too long; possible loop");
}
/*
** Complete a table access: if 't' is a table, 'tm' has its metamethod;
** otherwise, 'tm' is NULL.
*/
void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
const TValue *tm) {
int loop; /* counter to avoid infinite loops */
lua_assert(tm != NULL || !ttistable(t));
for (loop = 0; loop < MAXTAGLOOP; loop++) {
if (tm == NULL) { /* no metamethod (from a table)? */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index"); /* no metamethod */
}
if (ttisfunction(tm)) { /* metamethod is a function */
luaT_callTM(L, tm, t, key, val, 1); /* call it */
return;
}
t = tm; /* else repeat access over 'tm' */
if (luaV_fastget(L,t,key,tm,luaH_get)) { /* try fast track */
setobj2s(L, val, tm); /* done */
return;
}
/* else repeat */
}
luaG_runerror(L, "gettable chain too long; possible loop");
}
/*
** Main function for table access (invoking metamethods if needed).
** Compute 'val = t[key]'
*/
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* 't' is a table? */
Table *h = hvalue(t);
const TValue *res = luaH_get(h, key); /* do a primitive get */
if (!ttisnil(res) || /* result is not nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
setobj2s(L, val, res); /* result is the raw get */
return;
}
/* else will try metamethod */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index"); /* no metamethod */
if (ttisfunction(tm)) { /* metamethod is a function */
luaT_callTM(L, tm, t, key, val, 1);
return;
}
t = tm; /* else repeat access over 'tm' */
}
luaG_runerror(L, "gettable chain too long; possible loop");
}
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
const TValue *res = luaH_get(h, key); /* do a primitive get */
if (!ttisnil(res) || /* result is not nil? */
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
setobj2s(L, val, res);
return;
}
/* else will try the tag method */
}
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 1);
return;
}
t = tm; /* else repeat with 'tm' */
}
luaG_runerror(L, "loop in gettable");
}
/*
** Finish a table assignment 't[key] = val'.
** If 'slot' is NULL, 't' is not a table. Otherwise, 'slot' points
** to the entry 't[key]', or to 'luaO_nilobject' if there is no such
** entry. (The value at 'slot' must be nil, otherwise 'luaV_fastset'
** would have done the job.)
*/
void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
StkId val, const TValue *slot) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm; /* '__newindex' metamethod */
if (slot != NULL) { /* is 't' a table? */
Table *h = hvalue(t); /* save 't' table */
lua_assert(ttisnil(slot)); /* old value must be nil */
tm = fasttm(L, h->metatable, TM_NEWINDEX); /* get metamethod */
if (tm == NULL) { /* no metamethod? */
if (slot == luaO_nilobject) /* no previous entry? */
slot = luaH_newkey(L, h, key); /* create one */
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, cast(TValue *, slot), val); /* set its new value */
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
}
else { /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
}
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
if (luaV_fastset(L, t, key, slot, luaH_get, val))
return; /* done */
/* else loop */
}
luaG_runerror(L, "'__newindex' chain too long; possible loop");
}
