Re: [Challenge] Smallest table copy

[Pierre-Yves Gérardy <pygy79@...>]

On Fri, May 9, 2014 at 12:21 AM, Philipp Janda <siffiejoe@gmx.net> wrote:
> Am 08.05.2014 20:11 schröbte Pierre-Yves Gérardy:
>
>> On Thu, May 8, 2014 at 5:35 PM, Philipp Janda <siffiejoe@gmx.net> wrote:
>>>
>>> Am 08.05.2014 17:24 schröbte Pierre-Yves Gérardy:
>>>>
>>>> L="local a,b,c=..."load(L.."")load(L.."")
>>>> function(a,b,c)endfunction(a,b)end
>>>
>>>
>>>
>>> Yes, and we also rely on upvalues, so we would need the `function`
>>> keyword
>>> in there after all ...
>>> But for a moment it was a good idea.
>>
>>
>> No need for upvalues, a Lua chunck really is a vararg function:
>>
>>      add = load"local a,b = ... return a + b"
>>      add(1,2) --> 3
>
>
> If you want to use the `type` (or `next`) function in there without passing
> it in every call, then you need them as upvalues. E.g.:
>
>     add = load[[
>       local t = ...
>       return function( a, b )
>         if t( a ) == t( b ) then
>           return a + b
>         end
>       end]]( type )
>
> Personally, I usually don't localize all globals in toy programs, but the OP
> seems to care. Better safe than sorry, I guess.

Indeed, I hadn't thought about that in this case (I actually use that
technique in two of my libraries).

—Pierre-Yves