[swift-evolution] Proposal Sketch: simplify optional unwrapping syntax

[Dave Abrahams]

> On Dec 19, 2015, at 12:37 PM, ilya via swift-evolution <swift-evolution at swift.org> wrote:
> 
> I prefer 
> 
> if let vc = someInterestingViewConroller {
>   vc.doSomething()
> }
> 
> - Explicit is better than implicit
> - shadowing is bad 
> - now there's no ambiguity about how to change the original property. 
> 
> Therefore I'm -1 on any proposal that hides explicit name binding and/or increases shadowing, including let foo and unwrap foo. 

+1 to that.  IMO re-using the same name for the unwrapped version of an optional variable does not help readability, and I don't want to encourage it.  In a localized context like this, a short name is often better anyway as it declutters the code inside the block.

> 
> On Sat, Dec 19, 2015 at 21:31 Kevin Wooten via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
> As much fun as it to example with foo, I would argue the opposite when you use some real world variable names:
> 
> if let someInterestingViewConroller = someInterestingViewConroller {
> }
> 
> vs
> 
> If let someInterestingViewConroller {
> }
> 
> We know what let does and it should be enough to impart the necessary information for this statement.
> 
> When it comes to newcomers I think you'd be hard pressed to find somebody who'd be able to understand either form without teaching; so not losing much there.
> 
> 
> On Dec 19, 2015, at 10:01 AM, Chris Lattner via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
> 
>> 
>>> On Dec 11, 2015, at 8:19 AM, Jeff Kelley via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
>>> 
>>> I’ve had similar ideas to this. Instead of ditching the if let syntax altogether, another approach would be to use the existing name if no new name is given, so that this code:
>>> 
>>> 	if let foo = foo { /* use foo */ }
>>> 
>>> could become this code:
>>> 
>>> 	if let foo { /* use foo */ }
>>> 
>>> In both cases, foo is non-optional inside the braces. If you gave it another name with the if let syntax, that would work as it does today.
>> 
>> Hi Jeff,
>> 
>> This is commonly requested - the problem is that while it does help reduce boilerplate, it runs counter to the goal of improving clarity.
>> 
>> -Chris
>> 
>> 
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-Dave



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