[swift-evolution] [Proposal] Revamp the playground quicklook APIs

[Chris Lattner]

> On Jan 9, 2018, at 11:30 PM, Saagar Jha <saagar at saagarjha.com> wrote:
>> 
>> In short, can we change playgroundRepresentation to return Any instead of Any?.  Among other things, doing so could ease the case of playground formatting Optional itself, which should presumably get a conditional conformance to this.  :-)
> 
> I believe the rationale behind this was to provide a way to “opt-out” of a customized representation, although now that I think about it, what exactly does the default mean? In particular, what happens in this case?

If you want a type to display as nothing (e.g. to avoid the perf impact of formatting it) just make the playground representation be an empty string or something.

-Chris