[swift-evolution] Optionals and nil in Switch statement

[Nevin Brackett-Rozinsky]

I just got home and tested. The answer is yes, `case "text"?` does work.

let optStr : String? = "text"
switch optStr {
case nil     : print("Nil")
case "text"? : print("Success")
default      : print("Default")
}
// Prints `Success`

Nevin

On Tue, Jun 28, 2016 at 12:27 PM, Nevin Brackett-Rozinsky <
nevin.brackettrozinsky at gmail.com> wrote:

> Does `case "text"?` work?
>
>
> On Tuesday, June 28, 2016, Kevin Nattinger via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>> Case .none:
>> Case .some("string"):
>>
>>
>> On Jun 28, 2016, at 06:40, Lucas Jordan via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>> Forgive me if this was/is discussed already, I am new to the process
>> here....
>>
>> (code is attached as a playground too)
>>
>>
>>
>> Sometimes when I am working with a String? nil can be a reasonable value,
>> and what I want to do is something like the following:
>>
>> import UIKit
>>
>>
>> var str:String? = "Hello, playground"
>>
>>
>> switch str{
>>
>> case nil:
>>
>>     print("Nil!")
>>
>> case "Hello, playground":  //it would be super nice if this worked.
>>
>>     print("Match")
>>
>> default:
>>
>>     print("Some other non nil value?")
>>
>> }
>>
>>
>> But it does not work, the orange  text is a compile time error,
>> "Expression pattern of type 'String' cannot match value of type 'String?'.
>> I realize that this can be replaced with a let statement (case let s
>> where s == "Hello, playground":), but that is verbose.
>>
>> Seems like the compiler could be OK with the orange text, since it is
>> clearly not nil.
>>
>> Thoughts?
>>
>> -Lucas
>>
>>
>>
>>
>>
>> <NilInSwitchStatements.playground.zip>
>>
>> _______________________________________________
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>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
>>
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