[swift-evolution] [Idea] if let value!

[Sean Heber]

Yep - same here. I think I was one of the first to propose we find some solution to this on the list back when it first started, and oddly enough, with more Swift experience comes less and less feeling of this even being a problem. I think as you start thinking more “in Swift” you start structuring your code differently, using guards, changing the nature of the flow, and suddenly these situations come up less often.

l8r
Sean


> On May 17, 2016, at 10:13 AM, Tony Allevato via swift-evolution <swift-evolution at swift.org> wrote:
> 
> While I've sometimes (early on) wished for a shorter-hand syntax for that construct, I've never been able to think of something that I thought was better. I've gotten to the point where I don't particularly mind it anymore.
> 
> Regarding the exclamation point specifically, seeing one of those in an expression context says to me "this thing will die horribly if it is nil/throws an error". Using it in this context where that's not the case would probably go against users' expectations.
> 
> 
> On Tue, May 17, 2016 at 8:05 AM Vladimir.S via swift-evolution <swift-evolution at swift.org> wrote:
> On 17.05.2016 16:51, Johan Jensen wrote:
>  > This was one of the first and most commonly suggested ideas, when the Swift
>  > Evolution mailing list first started.
>  > Chris Lattner sums it up
>  >
> <https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20151214/003546.html>
>  > in one of those threads:
>  >
>  >> This is commonly requested - the problem is that while it does help
>  > reduce boilerplate, it runs counter to the goal of improving clarity.
>  >
>  > — Johan
> 
> Oh, thank you for letting this know.
> 
> Well, I totally disagree with Chris. And as soon as there was no 'official'
> proposal and 'official' decision, I'd like to discuss this more.
> 
> I saw a lot of code like
> if let mySomeValue = mySomeValue {} in sources and even in books.
> Plus, I really believe that
> if let mySomeValue! {..} is better in any way: readability, less space for
> errors(when you need to repeat the same name) etc
> 
> FWIW, I suggest more explicit variant:
> if let value! {...} // with exclamation mark
> In that "old" proposal there was `if let value {...}`, was not so clear.
> 
> I can't accept an argument that you can use another name - as usually
> 'good' name is already 'crafted' for the instance and you want to use it in
> next code.
> Otherwise, we need a 'best practice' to name optional variables with some
> prefix or suffix like : mySomeValueOpt, then `if let mySomeValue =
> mySomeValueOpt` will have a sense. But as I understand, we don't want to
> use such approach.
> Additionally, when you shadow optional value with same name - you are
> *protecting* yourself from using optional value inside block of unwrapped
> code. IMO it is a good idea.
> And want we or don't want, we already have this practice widely. So I
> believe this(my) proposal will improve the code.
> 
> I'd like to get opinion of the community regarding this feature.
> 
> On 17.05.2016 16:51, Johan Jensen wrote:
> > This was one of the first and most commonly suggested ideas, when the Swift
> > Evolution mailing list first started.
> > Chris Lattner sums it up
> > <https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20151214/003546.html>
> > in one of those threads:
> >
> >> This is commonly requested - the problem is that while it does help
> > reduce boilerplate, it runs counter to the goal of improving clarity.
> >
> > — Johan
> >
> > On Tue, May 17, 2016 at 3:43 PM, Vladimir.S via swift-evolution
> > <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
> >
> >     It is common to shadow optional value name with unwrapped value with
> >     same name:
> >
> >     if let someGoodValue = someGoodValue {...}
> >
> >     What if we'll have a syntax to not repeat the variable name to achieve
> >     the same target:
> >
> >     if let someGoodValue! {...}
> >
> >     What do you think?
> >     _______________________________________________
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> >     swift-evolution at swift.org <mailto:swift-evolution at swift.org>
> >     https://lists.swift.org/mailman/listinfo/swift-evolution
> >
> >
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