Re: Next Version of Lua?

[Olivier Hamel <evilpineapple@...>]

Hans van der Meer wrote:
> Yes, it is an array of bits, packed as tight as can be. Bits in the 
> array can be set, queried and iterated on. The testfile in the package 
> does a prime number sieve of Eratosthenes as an example, showing that 
> very many boolean flags can be manipulated comfortably.
>
> Indeed, metamethods may be used for combining bitmaps with AND, OR, XOR.
>
> The module cannot do arithmetic operations(like i<<1 or i>>1 for doing 
> powers of two). It was not designed as such and I agree with the quote 
> of Roberto in that one should not lightly tamper with arithmetics.
>
> Hans van der Meer
In all respect, I beg to differ. Quite a few algorithms could be 
significantly improved/facilitated/made implementable with such direct 
bitwise ops, though I agree that adding << and >> just for performing 
powers of two is indeed a waste, but I'd only used those as an example. 
Your implementation seems to handle bitflags well, which is the main 
reason (for me at least, that + some algorithms) I'm hoping for bitwise 
ops. But I'd think it'd be more overhead/bother to do (sorry don't have 
the ref sheet with me ATM so please bear as I use the incorrect 
constructs/method calls):

local WASDActive = bitmap.Create(FLAG_KEYBOARD_W, FLAG_KEYBOARD_A, 
FLAG_KEYBOARD_S, FLAG_KEYBOARD_D)
ExplodePlayerIfWASDIsPressed(WASDActive:GetValue())

Instead of:

ExplodePlayerIfWASDIsPressed(FLAG_KEYBOARD_W | FLAG_KEYBOARD_A | 
FLAG_KEYBOARD_S | FLAG_KEYBOARD_D)

Adding your object as a core type might be a solution, but then that 
adds a kludge to Lua's otherwise (near-?)perfect type universe.