[swift-evolution] [Review] SE-0066: Standardize function type argument syntax to require parentheses

[Joe Groff]

> On Apr 26, 2016, at 1:33 PM, Chris Lattner via swift-evolution <swift-evolution at swift.org> wrote:
> 
> 
>> On Apr 26, 2016, at 5:56 AM, Vladimir.S via swift-evolution <swift-evolution at swift.org> wrote:
>> 
>> On 26.04.2016 9:38, Goffredo Marocchi via swift-evolution wrote:
>>> 
>>> Agreed, the exception for the parameter list in a closure declaration
>>> should be gone too potentially, I do not see a very convincing case why we
>>> should keep it. Does it solve some particular problem now in its current form?
>> 
>> Probably support. If we want to be clear about if parameter list is a tuple or it is a list of values i.e. (Int,Int) -> Void  vs  ((Int,Int)) -> Void , IMO we should be also clear about parameter list in a closure declaration..
>> 
>> But it seems right now it is not just about syntax:
> 
> Yes, closure expressions have other problems.  For example, if a closure expression contextually takes two parameters, it is invalid to use $0 without also using $1.  :-(

IIRC that restriction arose out of tuple splatting ambiguities, so we should be able to fix now that we've done away with splatting (as another proposal, of course).

-Joe