Re: Bytecode hacks

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

> So I wanna do a t:[var]() operator (which's pretty much t:name() but it 
> takes a var instead of a name) and I have no idea of how to do it...

The SELF instruction already supports this, but the parser does not.
Consider this code:
       local t={}
       t.f=print
       local v="f"
       t:x(1)

The bytecode is
	1	[1]	NEWTABLE 	0 0 0
	2	[2]	GETTABUP 	1 0 -2	; _ENV "print"
	3	[2]	SETTABLE 	0 -1 1	; "f" -
	4	[3]	LOADK    	1 -1	; "f"
	5	[4]	SELF     	2 0 -3	; "x"
	6	[4]	LOADK    	4 -4	; 1
	7	[4]	CALL     	2 3 1
	8	[4]	RETURN   	0 1

Changing the SELF instruction to
	5	[4]	SELF     	2 0 1
gives the right result, that is, calls t:[v](1). The third operand in SELF
is the location of the key. In the original code, it's the constant #3, "x".
In the modified code, it's the register #1, which is the local variable v,
and that contains "f".

I think there are patchs around for the t:[var]() syntax.