[swift-evolution] [Pitch] Introduce user-defined dynamically "callable" types

[Chris Lattner]

> On Nov 10, 2017, at 10:57 AM, Alejandro Martinez via swift-evolution <swift-evolution at swift.org> wrote:
> 
> This seems a really interesting solution Chris.
> Similar to what Joe mentions I think this would also be appreciated by
> the community to make even nicer DSLs in Swift, which may or may not
> be a good side effect of the proposal.
> Also, I'm just wondering, how much complication adds this to the
> compiler itself that would have to be maintained in the future?

This is a very localized and simple change to the compiler.  Assuming the pitch process goes well, I will provide an implementation.

-Chris