Re: string.gsub accepting a callable userdata

[Jerome Vuarand <jerome.vuarand@...>]

2012/12/13 Rena <hyperhacker@gmail.com>:
> You want __mode='v', not __weak.

Yes, of course :-)

> And I'm not sure why you're using a table
> to store that one item. It's not necessary to use a table to create local
> upvalues:

But then you get a hard reference to the userdata object, and that may
change its lifetime.

> local gsub,type = string.gsub,type
> local ref
> local function unref(...) return ref(...) end
>
> function string.gsub(s,pat,repl)
>    if type(repl) == 'userdata' then
>       ref = repl
>
>       repl = unref
>    end
>    return gsub(s,pat,repl)
> end
>
> Although this function just looks like an elaborate noop... is it needed at
> all?

What function, unref or the new string.gsub? The point of this whole
topic is to be able to pass a callable userdata to string.gsub, which
these two function achieve, so I don't think it's a no-op.