Perhaps it should provide a Fix-It, but I don't see it as an an issue, more as
an opportunity to understand the pattern matching behind it :)
> On 29 Jun 2016, at 08:59, Charlie Monroe <char...@charliemonroe.net> wrote:
>
> Yes, you get a warning. But I don't see why it should - when you're matching
> against an optional, it's evident that you mean .some("Hello")... This should
> be automatically inferred.
>
> I find this a confusing part of the switch statement where
>
> let obj: Any? = "Hello"
>
> switch obj {
> case let str as String:
> print("Hey, found String!")
> default:
> print("No find.")
> }
>
> will print "Hey found String", but it won't allow you to match against a
> string literal. This is one of the first things that I found confusing when I
> first learned Swift.
>
>> On Jun 29, 2016, at 8:49 AM, David Hart <da...@hartbit.com> wrote:
>>
>> I don't see it as a bug. The if statement calls an equality function which
>> promotes the lhs to an Optional (or that accepts a non optional as lhs -
>> can't remember) but the switch statement does pattern matching. Does the the
>> compiler warn you when pattern matching an optional with a non-optional case?
>>
>>> On 29 Jun 2016, at 07:16, Charlie Monroe via swift-evolution
>>> <swift-evolution@swift.org> wrote:
>>>
>>> I nevertheless think that this is a bug and should be addressed. There is
>>> no reason where
>>>
>>> if stringOptional == stringNonOptional { ... }
>>>
>>> works, but pretty much the same construct doesn't work in the switch-case.
>>> It should be perhaps solved via a bugreport at http://bugs.swift.org and
>>> via evolution, though...
>>>
>>>> On Jun 29, 2016, at 12:31 AM, Nevin Brackett-Rozinsky via swift-evolution
>>>> <swift-evolution@swift.org> wrote:
>>>>
>>>> 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.brackettrozin...@gmail.com> wrote:
>>>>> Does `case "text"?` work?
>>>>>
>>>>>
>>>>>> On Tuesday, June 28, 2016, Kevin Nattinger via swift-evolution
>>>>>> <swift-evolution@swift.org> wrote:
>>>>>> Case .none:
>>>>>> Case .some("string"):
>>>>>>
>>>>>>
>>>>>>> On Jun 28, 2016, at 06:40, Lucas Jordan via swift-evolution
>>>>>>> <swift-evolution@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>
>>>>>>> _______________________________________________
>>>>>>> swift-evolution mailing list
>>>>>>> swift-evolution@swift.org
>>>>>>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>>>
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>>>> swift-evolution mailing list
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>>>
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>
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