The Generics Manifesto and single-element tuples

[Jens]

@xwu

The original question in this thread hasn't ever been answered because, essentially, it's unanswerable. Swift had one model of the relationship among parenthesized expressions, tuples, and parameter lists, but this was abandoned as unworkable. Now it has another model, but this has not been completely implemented. Difficulties arise from the fact that there is no complete implementation of any one design. The solution isn't to write off the design as flawed and to propose another one: that's how you get three incompletely implemented designs.

I agree that the solution isn't to write off the intended design as flawed. But discussions such as this, and also bug reporting and fixing, would probably be more productive if the intended model/design was clearly documented, including any relationship among tuples, parenthesized expressions, parameter lists, etc. Such a document should also make it clear if/how the model makes questions like "Does 1-tuples exist?" unanswerable/irrelevant.

Can someone more experienced than me please start a rough sketch?
(I suppose it would end up here as eg Tuples.md.)

This document could then be announced in a separate thread, and discussions like this could continue (more productively) there, while establishing a common understanding by referring to and improving the document.