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Subject: Re: [PHP-DEV] [RFC] Argument unpacking
From: smalyshev@sugarcrm.com (Stas Malyshev)

Hi!

> function short (...$args) {
>     if (count($args))
>         return long(...$args, "some value");
> }

This is exactly the problem. Since $args has undefined number of
arguments, there's no way to determine where "some value" ends up. Which
means it's impossible to understand what's going on here. Now, if we had
named arguments, like python had, then using "some value" as a named
argument might work (and we'd need to see what to do with named
arguments in this case), but as positional argument this just doesn't
make much sense beyond some very esoteric things that nobody uses
directly, without wrapping libraries (like partially applied functions)
- at least in PHP.

> And I think you are really arguing about non-issues.
> Example: Multiple uses of unpacking syntax makes sense when you call a
> function with a variadic parameter:
> 
> function variadic (...$args) {
>     // do something
> } 
> 
> variadic(...$array1, ...$array2);

Again, since parameters in PHP are positional, they have meaning
depending on position. If you just wanted to pass an array, pass an
array, you don't need to use variadic syntax for that. Variadic syntax
makes sense only if positions there have meanings and you want to give
specific meanings to specific arguments in specific positions. In that
case, ...$array1, ...$array2 doesn't work since you can not have
meaningful positions. Only case where it works if you do functional
operations like partial application, where the meaning of the function
is not important but only the fact that it is a function is important.
But I don't think we need special syntax to do such things.
-- 
Stanislav Malyshev, Software Architect
SugarCRM: http://www.sugarcrm.com/
(408)454-6900 ext. 227