Re: How to determine if all arguments are nil?

[Michael Broughton <mbobowik@...>]

I suspect that 2 is the best (and probably the fastest) way to do this. 
If you really don't want to create a table, then try one of these:

function f1(...)
   local n = select("#", ...)
   local b
   b = function(i, f, ...)
       if f ~= nil then
           return false
       elseif i == n then
           return true
       end
       return b(i + 1, ...)
   end
   return b(1, ...)
end

function f2(...)
   for i = 1, select("#", ...) do
       if select(i, ...) ~= nil then
           return false
       end
   end
   return true
end




Tim Hunter wrote:
> I have a varargs function. What is the Lua idiomatic way of 
> determining if all the arguments are nil? I've thought of two ways:
>
> 1. #{...} == 0
> 2. next{...} == nil
>
> This function is called very frequently, so I'd prefer not to have to 
> create a table if I can avoid it.