Re: Implementing GOTO/GOSUB

[Asko Kauppi <asko.kauppi@...>]

Well, you can emulate GOSUBs with GOTO, can't you.. (just conceptually,

	a=1
	__GOSUB=77
	a=2
	__GOSUB=77
	a=3
	__LABEL=77
	print(a)
	__RETURN

Where:
	__GOSUB=xx:	__RETURN_TO='#'..linenum; __GOTO=xx; __LABEL='#'..linenum
	__RETURN:	__GOTO=__RETURN_TO

This would probably need the use of C preprocessor (cpp) or something 
alike to do the macros (& get the linenums!).  Is that out of the 
question?


13.9.2004 kello 20:13, Luiz Henrique de Figueiredo kirjoitti:

 I tried to implement GOTO/GOSUB functionality in Lua.
> An year ago, prompted by a similar request here in lua-l, I wrote a 
> simple
> patch for luac that did the right thing for the code below:
>
>          a=1
>          __GOTO=12
>          __LABEL=99
>          print("bye",a)
>          do return end
>          a=2
>          __LABEL=12
>          print("hello",a)
>          a=3
>          __GOTO=99
>
> That is, it turned __GOTO into JMPs and __LABEL into NOPS.
> This worked great for GOTO but I don't think it will work for GOSUB 
> ... RETURN.
> --lhf