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- Subject: Re: Proposal: Trailing comma in function calls
- From: Tom N Harris <telliamed@...>
- Date: Wed, 04 Jun 2014 16:20:28 -0400
On Wednesday, June 04, 2014 05:15:23 PM Dirk Laurie wrote:
> More generally, "lexical void" inside an argument list could mean nil.
> That is something that I (when in a bikeshedding mood) have sometimes
> missed, with some library functions where I use seldom use the early
> arguments, e.g.
I like this. And on the left side too.
first,,third = something()
Assigns the first and third values while dropping the second without having to
assign a dummy variable.
> But now, in your example, I don't suppose you want
> to mean
> print('this is a string', 'another string', 'yet another string', nil )
> or would you?
You can have both. The formal definition of an unnamed element in a comma list
is "nothing". That is,
print() -- is not the same as
print(nil) -- thus
print(,) -- is not the same as
It's not that you're ignoring the last comma when there's no variable after
it, you're implying the last comma after a variable name. Then the number of
arguments to the function is equal to the number of commas.