Re: A little bit about nothing (was Re: Empty? No. Array? No. Has? Yes.)
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- Subject: Re: A little bit about nothing (was Re: Empty? No. Array? No. Has? Yes.)
- From: Andrew Starks <andrew.starks@...>
- Date: Wed, 3 Jul 2013 12:03:45 -0500
This does not work though. Your version of something will always
report something, unless something is called:
function something(...)
if select('#',...) == 0 then
return false
else
local mary = ...
return true
end
end
print(something())
--false, good
local baz
print(something(baz))
--true, good
print(something(foo))
--true, bad
On Wed, Jul 3, 2013 at 11:53 AM, Pierre-Yves Gérardy <pygy79@gmail.com> wrote:
> On Wed, Jul 3, 2013 at 6:20 PM, Sean Conner <sean@conman.org> wrote:
>>
>> function something(mary) --[[ something about mary ]] end
>>
>> In straight Lua, there is no way for something to know if it was called
>> like:
>>
>> something()
>>
>> or
>>
>> something(nil)
>
> function something(...)
> if select('#',...) == 0 then
> -- something about nothing
> else
> local mary = ...
> -- something about mary
> end
> end
>
> That being said, it is not concise.
>
> -- Pierre-Yves
>