Re: Suggestion: lua_popinteger and others

[Rena <hyperhacker@...>]

On Tue, Apr 24, 2012 at 23:41, Rebel Neurofog <rebelneurofog@gmail.com> wrote:
> On Wed, Apr 25, 2012 at 8:57 AM, Rena <hyperhacker@gmail.com> wrote:
>> On Tue, Apr 24, 2012 at 22:50, Rebel Neurofog <rebelneurofog@gmail.com> wrote:
>>> On Tue, Apr 24, 2012 at 11:00 AM, Rena <hyperhacker@gmail.com> wrote:
>>>> Right now if you want to retrieve a field using the C API, it takes
>>>> three lines per field:
>>>> lua_getfield(L, index, "field name");
>>>> lua_Integer val = lua_tointeger(L, -1);
>>>> lua_pop(L, 1);
>>>
>>> static inline lua_Integer get_integer (lua_State *L, int idx, const char *field)
>>> {
>>>    lua_getfield(L, idx, field);
>>>    lua_Integer val = lua_tointeger(L, -1);
>>>    lua_pop(L, 1);
>>>    return val;
>>> }
>>>
>>> In modern compilers inlining avoids unnecessary data copying so this
>>> is at least optimal.
>>> Although inlining isn't ASNI C.
>>>
>>
>> That's what I've done in my app. I was just proposing that such a
>> function should be part of the API.
>>
>
> Well, once again, inlining isn't ANSI C.
> And for now there's no inlining in Lua ()
> So adding lua_popinteger () is either suboptimal or takes duplication of
> big piece of code:
>
> LUA_API lua_Integer lua_popinteger (lua_State *L, int idx) {
>  TValue n;
>  const TValue *o = index2adr(L, idx);
>  if (tonumber(o, &n)) {
>    lua_Integer res;
>    lua_Number num = nvalue(o);
>    lua_number2integer(res, num);
> +  lua_pop(L, 1);
>    return res;
>  }
>  else
> + {
> +  lua_pop(L, 1);
>    return 0;
> + }
> }
>

Who mentioned inlining? Surely any overhead incurred is offset by
having only one function to call instead of two?

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