Re: Lua Wrapping

[David Morris-Oliveros <david@...>]

Ok, i think i got it..

Being new to lua, i don't quite know my way around that well, and i 
ended up shooting myself in the foot. Repeatedly.

The way i'm going to do it is, having only 1 table:

Vec2 = {
   __index = function(table, key)
       if getmetatable(table)[key] then
           return getmetatable(table)[key]
       end
      -- handle my C++ properties nicely
   end;
   new = function (self, x,y)
       return setmetatable({}, Vec2 );
   end;
   mag = function (self)
       return math.sqrt(self.x * self.x + self.y * self.y)
   end;
}

That way, when lua goes to execute this:

v = Vec2:new()
print (v:mag())

It will see that 'v' doesn't have 'mag', will go to its metatable's 
metamethod '__index', which will look it up it v's metatable (Vec2), and 
then return it, and since it's a function, will execute it with whatever 
params it has.
If it doesn't have 'mag', then it will assume that it's a property and 
handle it.

I suppose this is just a simple dispatcher. It works nicely in lua, and 
i thing think i'll have any problems in the C++ side.

Is this the "correct" approach?
Any better way of doing it?


David Morris-Oliveros wrote:

> First of all, sorry for the very very long post. If things like these 
> are considered bad, please let me know. Thanks

[...snip...]

--
// David Morris-Oliveros
// Camera Coder
// Team Bondi


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