Lua table of string values as parameter in C function

Question

I want to make a C function that takes a lua table with strings as parameter, and the lua table does not have any keys, just values. How can I do this? I cannot figure it out. I did not find anything when I searched in google.

Did you take a look at Programming in Lua book? Especially the chapter 24 — hjpotter92, Mar 12 '15 at 21:59
@hjpotter92 No, I will take a look tomorrow, thanks for the suggestion — Erik W, Mar 12 '15 at 22:04
Do you know how tables work in Lua? (hint: they contain key/value pairs, there are no keys without values or values without keys) — user253751, Mar 12 '15 at 22:06
@immibis But they have a default key when you don,t specify one yourself right? — Erik W, Mar 13 '15 at 07:01
@ErikW The default keys are consecutive integers starting from 1. — user253751, Mar 13 '15 at 07:47

score 1 · Accepted Answer · answered Mar 13 '15 at 21:11

The "default" keys in a table are consecutive integers starting from 1. This:

{"hello", "world"}

is the same as:

{[1] = "hello", [2] = "world"}

You cannot access these entries with lua_getfield, because that takes a string key. You can do it the "manual" way, with lua_pushnumber and lua_gettable. If L is your lua_State*, t is the index of the table on the stack and and k is the key, then:

lua_pushnumber(L, k);
lua_gettable(L, t);

should do the same thing as:

lua_getfield(L, t, k);

does for string keys. Note that if t is a relative index (a negative number), then because you're pushing another item onto the stack, you'll need to adjust it by 1.

Lua table of string values as parameter in C function

1 Answers1