Re: Multi-indexed tables

[Dibyendu Majumdar <mobile@...>]

On Sun, 9 Dec 2018 at 19:46, Dibyendu Majumdar <mobile@majumdar.org.uk> wrote:
> On Sun, 9 Dec 2018 at 18:12, Dirk Laurie <dirk.laurie@gmail.com> wrote:
> >
> > 1. Is there any syntactic reason why one can't patch Lua so that
> > t[1,2] won't raise a compilation error, but instead invoke
> > __index(t,1,2) or __newindex(t,1,2,v)?
>
> I think there are issues with the way the table op codes work - and
> the number of registers they allow.
>
> GETTABLE A B C   R(A) := R(B)[RK(C)]
> SETTABLE A B C   R(A)[RK(B)] := RK(C)
>
> The opcode doesn't have room for additional registers.
>
> Lua's parsing also assumes that there is a single register for the key.
>

Also see:

http://lua-users.org/lists/lua-l/2018-03/msg00088.html