Re: Call a Lua function from C

[David Jones <drj@...>]

On Feb 02, 2005, at 14:45, Michael Cumming wrote:

> Adam, Rici,
>
> Thank you for the replys... so a quick guess at the code would be...
>
> if (lua_isfunction (L,1)) // we have a function
>
>    luacallbackfunction = luaL_ref(L, LUA_REGISTRYINDEX);
>
>
> When I want to use the function I can do
>
> lua_rawgeti(L, LUA_REGISTRYINDEX, luacallbackfunction);
> lua_pushxxx for the params
>
> lua_pcall (xxx)

Looks about right.

By the way, since tables and userdata can also be called if they have 
the correct metamethod then it is bad practice to use lua_isfunction to 
test if a value is callable.  I might, quite reasonably, pass in a 
"function" that was in fact a userdata that implemented the __call 
metamethod and your code would barf.  On the other hand, I appreciate 
that you would like _some_ sanity check.

David Jones