[swift-evolution] [Proposal] function "return" optional keyword.

[ilya]

-1 on inferred return type and omitting return with func

Both features are actually available in the language as-is, just not with
the func keyword:

let someInferredFunction = { _ in 5}  // () -> Int

When teaching Swift we actually teach func + return keywords together, they
make it easy to see all possible return paths from a function.

And we recommend using func instead of a closure when there is a multiline
body with control statements. Having implicit return in that case hurts
readability.  For example, out of three possible return points within this
function only one is not marked with return:

func f(input: Int) -> Int {
    if input > 10 {
        return 10
    }
    if input < 0 {
        return 0
    }
    input
}


+1 on omitting return from var {} declaration, those methods look like
closures and will often be one-liners.


On Sun, Dec 20, 2015 at 5:29 AM, Craig Cruden via swift-evolution <
swift-evolution at swift.org> wrote:

> I looked at the discussion and it looked like they were discussion two
> things combined.
>    - inferred return type (on function signature)
>    - and omitting return on the return.
>
> I agree with Chris on the fact that the function should have the type of
> return specified on the signature and not inferred since it is useful for
> API documentation to know that ahead of time on a strongly typed language.
>
> What is not necessary is actually forcing people to type return “x” on the
> last line - since “return” is rather redundant and clutter for those people
> of a functional programming paradigm point of view.
>
>
> On 2015-12-20, at 4:15:15, Stephen Christopher via swift-evolution <
> swift-evolution at swift.org> wrote:
>
> The discussion I was remembering, comment courtesy of Chris:
> https://devforums.apple.com/message/1014317#1014317
>
> (linked from https://devforums.apple.com/thread/255242)
>
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