void luaT_trybinassocTM (lua_State *L, const TValue *p1, const TValue *p2,
StkId res, int inv, TMS event) {
if (inv)
luaT_trybinTM(L, p2, p1, res, event);
else
luaT_trybinTM(L, p1, p2, res, event);
}
void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
TValue *res) {
switch (op) {
case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
case LUA_OPSHL: case LUA_OPSHR:
case LUA_OPBNOT: { /* operate only on integers */
lua_Integer i1; lua_Integer i2;
if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
setivalue(res, intarith(L, op, i1, i2));
return;
}
else break; /* go to the end */
}
#ifndef _KERNEL
case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
lua_Number n1; lua_Number n2;
if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
setfltvalue(res, numarith(L, op, n1, n2));
return;
}
else break; /* go to the end */
}
#endif
default: { /* other operations */
#ifndef _KERNEL
lua_Number n1; lua_Number n2;
if (ttisinteger(p1) && ttisinteger(p2)) {
setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
return;
}
else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
setfltvalue(res, numarith(L, op, n1, n2));
return;
}
#else /* _KERNEL */
lua_Integer i1; lua_Integer i2;
if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
setivalue(res, intarith(L, op, i1, i2));
return;
}
#endif
else break; /* go to the end */
}
}
/* could not perform raw operation; try metamethod */
lua_assert(L != NULL); /* should not fail when folding (compile time) */
luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
}
/*
** Main operation for concatenation: concat 'total' values in the stack,
** from 'L->top - total' up to 'L->top - 1'.
*/
void luaV_concat (lua_State *L, int total) {
lua_assert(total >= 2);
do {
StkId top = L->top;
int n = 2; /* number of elements handled in this pass (at least 2) */
if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1))
luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT);
else if (isemptystr(top - 1)) /* second operand is empty? */
cast_void(tostring(L, top - 2)); /* result is first operand */
else if (isemptystr(top - 2)) { /* first operand is an empty string? */
setobjs2s(L, top - 2, top - 1); /* result is second op. */
}
else {
/* at least two non-empty string values; get as many as possible */
size_t tl = vslen(top - 1);
TString *ts;
/* collect total length and number of strings */
for (n = 1; n < total && tostring(L, top - n - 1); n++) {
size_t l = vslen(top - n - 1);
if (l >= (MAX_SIZE/sizeof(char)) - tl)
luaG_runerror(L, "string length overflow");
tl += l;
}
if (tl <= LUAI_MAXSHORTLEN) { /* is result a short string? */
char buff[LUAI_MAXSHORTLEN];
copy2buff(top, n, buff); /* copy strings to buffer */
ts = luaS_newlstr(L, buff, tl);
}
else { /* long string; copy strings directly to final result */
ts = luaS_createlngstrobj(L, tl);
copy2buff(top, n, getstr(ts));
}
setsvalue2s(L, top - n, ts); /* create result */
}
total -= n-1; /* got 'n' strings to create 1 new */
L->top -= n-1; /* popped 'n' strings and pushed one */
} while (total > 1); /* repeat until only 1 result left */
}
