Re: varargs & table.insert()?

[Stefan Brantschen <sbr@...>]

On 3 Aug 2007 Stefan Brantschen wrote:

> > > How does one generalize that to insert a value anywhere in a  
> > > varargs?
> > rewrite table.insert in Lua, so it will use xxx.n, not #n. something
> > like:
> >
> > local function NewInsert (tbl, position, value)
> >   if position <= tbl.n then
> >     for f = tbl.n, position, -1 do tbl[f+1] = tbl[f]; end;
> >   end;
> >   tbl[position] = value;
> >   return tbl;
> > end;
>
> I'd simply use (t.n is the number of elements in the table):
>
> local function new_insert(t, val, pos)
>   pos = pos or t.n + 1
>   table.insert(t, pos, val)
>   t.n = t.n + 1
>   return t
> end

Rubbish. Sorry. I /really/ thought (based on some testing)  
table.insert handles tables with nils in case you explicitly indicate  
the insert position, but it does not. (And yes, t.n = t.n + 1 is also  
wrong, table.maxn might do the trick.) Ouch. Not my day.