Re: dynamically associating functions with lua

[Luiz Henrique de Figueiredo <lhf@...>]

>The only thought i have is to auto generate a lua script that implements 
>a function stub of the same name as the the dll function, push the 
>function name and all its parameters into a table and call a 'c' side 
>do_function_call that pulls this info and makes the call.

A simpler way is to expose a table with an __index metamethod that routes
the call to a single C function.

Here is what I've doing in my binding for GIMP:

 local router=gimp
 gimp={router=router}
 setmetatable(gimp,{
	 __index=function (t,k)
		 local f=function (...) router(k,unpack(arg)) end
		 rawset(t,k,f)
		 return f
	 end
 })

 gimp.gimp_message("Hello from GIMP and Lua!")
 gimp.extension_db_browser(0)

Note that "gimp" is the single C function that is exported by C. The code
above immediately redefines "gimp" to be a table with an __index metamethod
that does the routing. Note that the routing is by demand and that once
a function is called it becomes part of the table, that is, the __index
metamethod is called at most once for each function.
--lhf