[swift-evolution] [pitch] Eliminate the "T1 -> T2" syntax, require "(T1) -> T2"

hitstergtd+swiftevo at gmail.com hitstergtd+swiftevo at gmail.com
Fri Apr 15 00:05:29 CDT 2016


Chris,

The proposed syntax looks and reads so much better! +1.

On 15 April 2016 at 05:57, Chris Lattner via swift-evolution
<swift-evolution at swift.org> wrote:
> We currently accept function type syntax without parentheses, like:
>
>   Int -> Float
>   String -> ()
>
> etc.  The original rationale aligned with the fact that we wanted to treat all functions as taking a single parameter (which was often of tuple type) and producing a tuple value (which was sometimes a tuple, in the case of void and multiple return values).  However, we’ve long since moved on from that early design point: there are a number of things that you can only do in a parameter list now (varargs, default args, etc), implicit tuple splat has been removed, and  the compiler has long ago stopped modeling function parameters this way.  Beyond that, it eliminates one potential style war.
>
> Given all this, I think it makes sense to go for syntactic uniformity between parameter list and function types, and just require parenthesis on the argument list.  The types above can be trivially written as:
>
>   (Int) -> Float
>   (String) -> ()
>
> Thoughts?
>
> -Chris
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution


More information about the swift-evolution mailing list