The nil check and creating an empty array have very similar performance, in my naïve testing.
Saagar Jha > On Jul 28, 2016, at 14:59, Jacob Bandes-Storch via swift-users > <swift-users@swift.org> wrote: > > 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 <rm...@latencyzero.com > <mailto:rm...@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 <jtban...@gmail.com > > <mailto:jtban...@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@swift.org <mailto:swift-users@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 > > rm...@latencyzero.com <mailto:rm...@latencyzero.com> > > > > > > _______________________________________________ > > swift-users mailing list > > swift-users@swift.org <mailto:swift-users@swift.org> > > https://lists.swift.org/mailman/listinfo/swift-users > > <https://lists.swift.org/mailman/listinfo/swift-users> > > > > > -- > Rick Mann > rm...@latencyzero.com <mailto:rm...@latencyzero.com> > > > _______________________________________________ > swift-users mailing list > swift-users@swift.org > https://lists.swift.org/mailman/listinfo/swift-users
_______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
