> On Feb 6, 2017, at 11:08, Daniel Duan <[email protected]> wrote:
> 
> 
>> On Feb 6, 2017, at 10:58 AM, Jordan Rose <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> I think I see Alex's point here. Optional chaining is still intended to be a 
>> substitute for Objective-C's nil-swallowing, and therefore foo?.bar() should 
>> not warn if 'bar' has a discardable result, even though there is semantic 
>> information about whether the method was actually called. I think that of 
>> the three things under consideration here:
>> 
>> 1. foo?.bar() should not warn
>> 2. foo.map(baz) should warn
>> 3. Ternaries should be consistent with non-ternaries
>> 
> 
> I 100% agree with this analysis.
> 
>> #1 is the most important, at least to me. The Swift 3 change was to 
>> sacrifice #2 in favor of #3, which I'm not sure I would have done, but I 
>> wouldn't want to sacrifice #1 in favor of #2.
>> 
>> I wouldn't mind the model of the type being '@discardableResult 
>> Optional<Void>' or whatever, but I think that's probably more work than 
>> anyone wants to sign up for.
> 
> I’ll give this a go and report back. *crosses fingers*

I suspect this will entail making a new sugared type kind and then threading it 
carefully through the constraint solver (hence why I said it's probably more 
work than you want to take on).

Jordan

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