[swift-evolution] Proposal: Deprecate optionals in string interpolation
dan.appel00 at gmail.com
Wed May 18 17:56:09 CDT 2016
Optional(foo) better depicts the actual type (it's an options string, after
all). If you're not happy with it, just use the nil coalescing operator
such as "\(foo ?? "")". This is from the same series of proposals as
implicit casting - there are reasons it's done the way it is.
On Wed, May 18, 2016 at 3:49 PM Jacob Bandes-Storch via swift-evolution <
swift-evolution at swift.org> wrote:
> +1, personally I have taken to using `x+"str"+y` instead of
> `"\(x)str\(y)"`, if x/y are strings, so I can get a compile-time error if I
> do this accidentally.
> But I do see the appeal of being able to print("the data: \(data)") for
> simple use cases. Didn't someone earlier propose some modifiers/labels like
> "\(describing: x)" ?
> On Wed, May 18, 2016 at 11:50 AM, Krystof Vasa via swift-evolution <
> swift-evolution at swift.org> wrote:
>> The string interpolation is one of the strong sides of Swift, but also
>> one of its weaknesses.
>> It has happened to me more than once that I've used the interpolation
>> with an optional by mistake and the result is then far from the expected
>> This happened mostly before Swift 2.0's guard expression, but has
>> happened since as well.
>> The user will seldomly want to really get the output
>> "Optional(something)", but is almost always expecting just "something". I
>> believe this should be addressed by a warning to force the user to check
>> the expression to prevent unwanted results. If you indeed want the output
>> of an optional, it's almost always better to use the ?? operator and supply
>> a null value placeholder, e.g. "\(myOptional ?? "<<none>>")", or use
>> myOptional.debugDescription - which is a valid expression that will always
>> return a non-optional value to force the current behavior.
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>> swift-evolution at swift.org
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