Re: Userdata with methods *and* table access.

[Rici Lake <lua@...>]

On 14-Oct-04, at 2:39 PM, Tom Spilman wrote:

>  I was considering hashes, but doesn't Lua internally keep a hashed 
> version
> of the string?  Is there a way to get to that?  Or can I count on the 
> const
> char pointer returned from lua_tostring to be the same for the same 
> strings
> (this sounds really hacky)?  As it is now my innermost scripted loops 
> are
> doing string compares at the binding layer which makes them less 
> efficient
> than they could be with a good hash.

You can count on the char pointer to be the same provided the string 
never gets garbage collected. (i.e., if you keep a reference to the 
string somewhere.)

In that case, though, you might as well use the Lua string itself as a 
key into a table whose values are, for example, a structure of getter 
and setter functions for that key.

(Remember that technically function pointers cannot be cast to void* 
but a struct whose members are function pointers can.)

>   Tom