Re: Issues with the current varargs implementation (Was: Re: inadequate documentation for select and table.unpack)

[Sean Conner <sean@...>]

It was thus said that the Great Patrick Donnelly once stated:
> On Tue, Jun 21, 2016 at 3:22 PM, Soni L. <fakedme@gmail.com> wrote:
> > But varargs (and thus varargs-based arrays) are nil-safe by default.
> 
> Show me in the manual where it says **tables** are not nil safe and
> I'll stop posting to lua-l*.

  Lua 5.3, section 3.4.7:

	Unless a __len metamethod is given, the length of a table t is only
	defined if the table is a sequence, that is, the set of its positive
	numeric keys is equal to {1..n} for some non-negative integer n. In
	that case, n is its length. Note that a table like

	     {10, 20, nil, 40}

	is not a sequence, because it has the key 4 but does not have the
	key 3.  (So, there is no n such that the set {1..n} is equal to the
	set of positive numeric keys of that table.) Note, however, that
	non-numeric keys do not interfere with whether a table is a
	sequence.

  But for this discussion:

function foo(...) print(select('#',...) end
function bar(t)   print(#t)             end

foo(1,2,3,4)
4
bar{1,2,3,4}
4
foo(nil,nil,3,nil)
4
bar{nil,nil,3,nil}
0

  -spc