[swift-evolution] [Pitch] Support for pure functions. Part n + 1.

[Florent Vilmart]

We could do:

pure let closure = { _-> Else in }

But given the scope capturing nature of closures I was actually wondering if this 'purity' should be applied to closures.

After all an inline defined func would do.

On Feb 17, 2017, 11:59 AM -0500, Matthew Johnson <matthew at anandabits.com>, wrote:
> How do you suggest a closure indicate its purity? Something like this?
>
> { pure in $0.property }
>
> > On Feb 17, 2017, at 10:57 AM, Florent Vilmart <florent at flovilmart.com (mailto:florent at flovilmart.com)> wrote:
> > We were discussing the topic yesterday with others and some suggested adding a pure keyword, for improved readability, just before the function declaration:
> >
> > Ex:
> >
> > pure func(a:Some) -> Else {}
> >
> >
> >
> > On Feb 17, 2017, 11:51 AM -0500, Matthew Johnson via swift-evolution <swift-evolution at swift.org (mailto:swift-evolution at swift.org)>, wrote:
> > >
> > > > On Feb 17, 2017, at 10:46 AM, David Sweeris via swift-evolution <swift-evolution at swift.org (mailto:swift-evolution at swift.org)> wrote:
> > > >
> > > > On Feb 17, 2017, at 08:21, Adrian Zubarev via swift-evolution <swift-evolution at swift.org (mailto:swift-evolution at swift.org)> wrote:
> > > >
> > > > >
> > > > > I haven’t yet read all the feedback in this topic but I’d like to throw some bikeshedding of mine into the room. :)
> > > > >
> > > > >
> > > > > How about this?
> > > > >
> > > > > Version 1: func(pure) …
> > > > > Version 2: func label(…) ~> ReturnType
> > > > >
> > > > >
> > > > >
> > > >
> > > > Version 2 is going to upset those who use "~>" as an operator.
> > > >
> > > > As the # of possible attributes grows, having an obvious grouping mechanism for them, like version 1, might be worthwhile simply to help make the list clearer. What about allowing "@(list, of, attributes)" instead of "@list, @of, @attributes”?
> > >
> > > That would be a little bit awkward for attributes that are parameterized. And if we did do this we should allow the parens to be omitted when there is only one attribute.
> > > >
> > > > - Dave Sweeris _______________________________________________
> > > > swift-evolution mailing list
> > > > swift-evolution at swift.org (mailto:swift-evolution at swift.org)
> > > > https://lists.swift.org/mailman/listinfo/swift-evolution
> > >
> > > _______________________________________________
> > > swift-evolution mailing list
> > > swift-evolution at swift.org (mailto:swift-evolution at swift.org)
> > > https://lists.swift.org/mailman/listinfo/swift-evolution
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20170217/1b2b5434/attachment.html>