[swift-evolution] [Review] SE-0084: Allow trailing commas in parameter lists and tuples

[Joe Groff]

> On May 11, 2016, at 10:14 AM, Vladimir.S <svabox at gmail.com> wrote:
> 
> In this case (if this is a such good feature) IMO we should think about making the trailing commas *required*. In this way we will be consistent in either do we have trailing commas in Swift or don't. Otherwise we'll have a zoo in our sources/projects.
> 
> I don't think we need to have the same rules for commas "everywhere we have comma-delimited syntax".

We've generally shied away from legislating style; see our rationale behind not requiring `self.` for an example:

https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160104/005478.html

In languages where trailing commas are pervasively allowed, such as Perl, Python, Ruby, and modern Javascript, I haven't seen any indication that this is a major problem. Less blood has definitely been shed over it than over bracing style and other style wars.

-Joe