[swift-users] Compact iteration of optional collection?

[Jacob Bandes-Storch]

You should test it out — I'd guess there's a good chance it gets optimized
out.
On Thu, Jul 28, 2016 at 2:58 PM Rick Mann <rmann at latencyzero.com> wrote:

> Yeah, I suppose that works. Feels a bit clunky, like the language lacks
> specific support for this (in that it provides specific support for so many
> other common constructs). But I guess I can make do with that.
>
> I suppose there's a bit of a performance hit, in that constructing an
> empty array and iterating over it is more expensive than a simple nil
> check, but that's unlikely to cause issues in practice.
>
> Thanks.
>
> > On Jul 28, 2016, at 14:56 , Jacob Bandes-Storch <jtbandes at gmail.com>
> wrote:
> >
> > How about "for item in someOptionalContainer ?? []"  ?
> >
> > On Thu, Jul 28, 2016 at 2:55 PM, Rick Mann via swift-users <
> swift-users at swift.org> wrote:
> > I often call methods that return an optional collection. I then iterate
> over it. The problem is, it's a bit cumbersome to write:
> >
> >      if let container = someOptionalContainer
> >     {
> >         for item in container
> >         {
> >         }
> >     }
> >
> > I wish I could just write
> >
> >     for item in someOptionalContainer
> >     {
> >     }
> >
> > such that if the optional is nil, it just skips the iteration altogether.
> >
> > Is there a syntax for that (especially in Swift 3)?
> >
> >
> > --
> > Rick Mann
> > rmann at latencyzero.com
> >
> >
> > _______________________________________________
> > swift-users mailing list
> > swift-users at swift.org
> > https://lists.swift.org/mailman/listinfo/swift-users
> >
>
>
> --
> Rick Mann
> rmann at latencyzero.com
>
>
>
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