need help understanding C API

[Patrick <patrick@...>]

Hello

I am trying to write a binding for Lua and I have hit a snag because I 
don't really understand the plain C API well enough.

Could someone please tell me if this is wrong..

If we do this:
int * foo

we have created a pointer that can accept an int's value at a specific 
memory location.

If we do this:
lua_State * foo

We have "prepared" a memory location for all kinds if types ints, chars, 
function pointers and so on that lua will need and when we do this:

foo = luaL_newstate()

We are propagating that memory location with values and that memory 
location is now a lua instance.

Did I get this right?



So this must be silly but I can't figure it out. I know this isn't good 
programming practice but if I do this:


lua_State *L;
L = luaL_newstate();

int main(void)
{ code continues.....



I get these errors:

hello.c:17:1: warning: data definition has no type or storage class 
[enabled by default]
hello.c:17:1: error: conflicting types for ‘L’
hello.c:16:12: note: previous declaration of ‘L’ was here
hello.c:17:5: warning: initialization makes integer from pointer without 
a cast [enabled by default]
hello.c:17:1: error: initializer element is not constant

If the space is allocated and propagated in global space would it not 
just be available later inside a function scope?

I have a binding generator that will help but it won't work inside 
function scope. I am trying to run it on globals and I am trying to 
learn more about the C API as I go along.

Thanks for reading

Happy birthday to Michal Kottman, my birthday is 2 hours away !

-Patrick